WorldWideScience

Sample records for vesicle proton pump

  1. Proton pump inhibitors

    Science.gov (United States)

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by glands in ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This is a ...

  2. Proton-pump inhibitors

    African Journals Online (AJOL)

    Proton-pump inhibitors (PPIs) work by binding irreversibly to the. H+/K+-ATPase pump of the parietal cell, leading to inhibition of acid production in approximately 70% of active pumps.1The result is a dramatic increase in gastric pH mitigating the deleterious effects of acid in gastro-oesophageal reflux disease (GORD) and.

  3. Plant proton pumps

    DEFF Research Database (Denmark)

    Gaxiola, Roberto A.; Palmgren, Michael Gjedde; Schumacher, Karin

    2007-01-01

    Chemiosmotic circuits of plant cells are driven by proton (H+) gradients that mediate secondary active transport of compounds across plasma and endosomal membranes. Furthermore, regulation of endosomal acidification is critical for endocytic and secretory pathways. For plants to react...

  4. Proton pump inhibitors and gastroenteritis

    NARCIS (Netherlands)

    R.J. Hassing (Robert); A. Verbon (Annelies); H. de Visser (Herman); A. Hofman (Albert); B.H.Ch. Stricker (Bruno)

    2016-01-01

    textabstractAn association between proton pump inhibitor (PPI) therapy and bacterial gastroenteritis has been suggested as well as contradicted. The aim of this study was to examine the association between the use of PPIs and occurrence of bacterial gastroenteritis in the prospective Rotterdam

  5. Proton Pump Inhibitors and Gastritis

    OpenAIRE

    Suzuki, Masayuki; Suzuki, Hidekazu; Hibi, Toshifumi

    2008-01-01

    Proton pump inhibitors (PPIs) are novel compounds that strongly inhibit the H+/K+-ATPase in the gastric parietal cells to cause profound suppression of acid secretion. Acid-generating ATPase, also known as vacuolar-type ATPase, is located in the lysozomes of leukocytes and osteoclasts and its activity is also reportedly influenced by treatment with PPIs. This concept is supported by the results of studies using autoradiography in which 3H-Lansoprazole uptake sites were clearly detected in the...

  6. Localization of the Proton Pump of Corn Coleoptile Microsomal Membranes by Density Gradient Centrifugation 1

    Science.gov (United States)

    Mandala, Suzanne; Mettler, Irvin J.; Taiz, Lincoln

    1982-01-01

    Previous studies characterizing an ATP-dependent proton pump in microsomal membrane vesicles of corn coleoptiles led to the conclusion that the proton pump was neither mitochondrial nor plasma membrane in origin (Mettler, Mandala, Taiz 1982 Plant Physiol 70: 1738-1742). To facilitate positive identification of the vesicles, corn coleoptile microsomal membranes were fractionated on linear sucrose and dextran gradients, with ATP-dependent [14C]methylamine uptake as a probe for proton pumping. On sucrose gradients, proton pumping activity exhibited a density of 1.11 grams/cubic centimeter and was coincident with the endoplasmic reticulum (ER). In the presence of high magnesium, the ER shifted to a heavier density, while proton pumping activity showed no density shift. On linear dextran gradients, proton pumping activity peaked at a lighter density than the ER. The proton pump appears to be electrogenic since both [14C]SCN− uptake and 36Cl− uptake activities coincided with [14C] methylamine uptake on dextran gradients. On the basis of density and transport properties, we conclude that the proton pumping vesicles are probably derived from the tonoplast. Nigericin-stimulated ATPase activity showed a broad distribution which did not coincide with any one membrane marker. PMID:16662755

  7. Proton pump inhibitors and osteoporosis

    DEFF Research Database (Denmark)

    Andersen, Bjarne Nesgaard; Johansen, Per Birger; Abrahamsen, Bo

    2016-01-01

    PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months and a di......PURPOSE OF REVIEW: The purpose of the review is to provide an update on recent advances in the evidence based on proton pump inhibitors (PPI) as a possible cause of osteoporosis and osteoporotic fractures. This review focuses, in particular, on new studies published in the last 18 months...... and a discussion of these findings and how this has influenced our understanding of this association, the clinical impact and the underlying pathophysiology. RECENT FINDINGS: New studies have further strengthened existing evidence linking use of PPIs to osteoporosis. Short-term use does not appear to pose a lower...... risk than long-term use. There is a continued lack of conclusive studies identifying the pathogenesis. Direct effects on calcium absorption or on osteoblast or osteoclast action cannot at present plausibly explain the mechanism. SUMMARY: The use of PPIs is a risk factor for development of osteoporosis...

  8. [Interaction between clopidogrel and proton pump inhibitors

    NARCIS (Netherlands)

    Harmsze, A.M.; Boer, A. de; Boot, H.; Deneer, V.H.; Heringa, M.; Mol, P.G.; Schalekamp, T.; Verduijn, M.M.; Verheugt, F.W.A.; Comte, M. le

    2011-01-01

    The drug interaction between proton pump inhibitors and clopidogrel has been the subject of much study in recent years. Contradictory results regarding the effect of proton pump inhibitors on platelet reactivity and on clinical outcome in clopidogrel-treated patients have been reported in

  9. Protons and how they are transported by proton pumps.

    Science.gov (United States)

    Buch-Pedersen, M J; Pedersen, B P; Veierskov, B; Nissen, P; Palmgren, M G

    2009-01-01

    The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells of plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological proton pumps emerge. Most notably, the minimal pumping apparatus of all pumps consists of a central proton acceptor/donor, a positively charged residue to control pK(a) changes of the proton acceptor/donor, and bound water molecules to facilitate rapid proton transport along proton wires.

  10. Protons and how they are transported by proton pumps

    DEFF Research Database (Denmark)

    Buch-Pedersen, Morten Jeppe; Pedersen, Bjørn Panyella; Nissen, Poul

    2008-01-01

    The very high mobility of protons in aqueous solutions demands special features of membrane proton transporters to sustain efficient yet regulated proton transport across biological membranes. By the use of the chemical energy of ATP, plasma-membrane-embedded ATPases extrude protons from cells...... of plants and fungi to generate electrochemical proton gradients. The recently published crystal structure of a plasma membrane H(+)-ATPase contributes to our knowledge about the mechanism of these essential enzymes. Taking the biochemical and structural data together, we are now able to describe the basic...... molecular components that allow the plasma membrane proton H(+)-ATPase to carry out proton transport against large membrane potentials. When divergent proton pumps such as the plasma membrane H(+)-ATPase, bacteriorhodopsin, and F(O)F(1) ATP synthase are compared, unifying mechanistic premises for biological...

  11. Toward hybrid proteo-polymeric vesicles generating a photoinduced proton gradient for biofuel cells

    Science.gov (United States)

    Choi, Hyo-Jick; Lee, Hyeseung; Montemagno, Carlo D.

    2005-09-01

    We describe our efforts towards constructing a hybrid protein-polymer vesicle device based on the photoactive protein, bacteriorhodopsin (BR), for applications in the area of biosensors and biofuel cells. Successful protein incorporation into biomimetic polymer vesicles is a prerequisite for developing hybrid 'nano-bio' integrated devices. We suggest a systematic procedure for creating energy transducing, protein-incorporating, functional vesicles, based on the morphological ternary diagram. First, we constructed the morphological ternary diagram of the water/ethanol/polymer system with a size distribution of vesicles. The polymer used was an ABA triblock copolymer, PEtOz-PDMS-PEtOz [poly(2-ethyl-2-oxazoline)-b-poly(dimethylsiloxane)-b-poly(2-ethyl-2-oxazoline)]. Second, we incorporated BR in the form of purple membrane (PM) into polymer vesicle membranes under several different conditions, based on the morphological ternary diagram. Generation of electrochemical energy by BR proton pumping was checked by monitoring the pH change in parallel with transmission electron microscope analysis. The morphology of the polymer vesicles changed very little with the addition of PM. This work shows that the morphological ternary diagram provides a systematic method for constructing successful hybrid BR-incorporating biomimetic polymer vesicles.

  12. Proton Pumps: Mechanism of Action and Applications

    Science.gov (United States)

    Lanyi, Janos K.; Pohorille, Andrew; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Recent progress in understanding molecular structures and mechanisms of action of proton pumps has paved the way to their novel applications in biotechnology. Proton pumps, in particular bacteriorhodopsin and ATP synthases, are capable of continuous, renewable conversion of light to chemical, mechanical or electrical energy, which can be used in macro- or nano-scale devices. The capability of protein systems incorporated into liposomes to generate ATP, which can be further used to drive chemical reactions, and to act as molecular motors has been already demonstrated. Other possible applications of such biochemical devices include targeted drug delivery and biocatalytic re actors. All these devices might prove superior to their inorganic alternatives.

  13. Proton pump inhibitors inhibit pancreatic secretion

    DEFF Research Database (Denmark)

    Wang, Jing; Barbuskaite, Dagne; Tozzi, Marco

    2015-01-01

    +/K+-ATPases are expressed and functional in human pancreatic ducts and whether proton pump inhibitors (PPIs) have effect on those. Here we show that the gastric HKα1 and HKβ subunits (ATP4A; ATP4B) and non-gastric HKα2 subunits (ATP12A) of H+/K+-ATPases are expressed in human pancreatic cells. Pumps have similar...... localizations in duct cell monolayers (Capan-1) and human pancreas, and notably the gastric pumps are localized on the luminal membranes. In Capan-1 cells, PPIs inhibited recovery of intracellular pH from acidosis. Furthermore, in rats treated with PPIs, pancreatic secretion was inhibited but concentrations...

  14. Proton pump inhibitors affect the gut microbiome

    NARCIS (Netherlands)

    Imhann, Floris; Bonder, Marc Jan; Vich Vila, Arnau; Fu, Jingyuan; Mujagic, Zlatan; Vork, Lisa; Feenstra, Ettje T.; Jankipersadsing, Soesma A; Cenit, Maria Carmen; Harmsen, Hermie J M; Dijkstra, Gerard; Franke, Lude; Xavier, Ramnik J; Jonkers, Daisy; Wijmenga, Cisca; Weersma, Rinse K; Zhernakova, Alexandra

    BACKGROUND AND AIMS: Proton pump inhibitors (PPIs) are among the top 10 most widely used drugs in the world. PPI use has been associated with an increased risk of enteric infections, most notably Clostridium difficile. The gut microbiome plays an important role in enteric infections, by resisting or

  15. [Interaction between clopidogrel and proton pump inhibitors].

    Science.gov (United States)

    Harmsze, Ankie M; de Boer, Anthonius; Boot, Henk; Deneer, Vera H M; Heringa, Mette; Mol, Peter G M; Schalekamp, Tom; Verduijn, Monique M; Verheugt, Freek W A; le Comte, Marianne

    2011-01-01

    The drug interaction between proton pump inhibitors and clopidogrel has been the subject of much study in recent years. Contradictory results regarding the effect of proton pump inhibitors on platelet reactivity and on clinical outcome in clopidogrel-treated patients have been reported in literature. Concomitant use of omeprazole and clopidogrel was found to decrease the exposure (AUC) to clopidogrel's active metabolite by 50% and to sharply increase platelet reactivity, as a result of inhibition by omeprazole of CYP2C19, a cytochrome P450 (CYP) enzyme. Pantoprazole has a much weaker effect on clopidogrel's pharmacokinetics and on platelet reactivity during concomitant use. The influence of the other proton pump inhibitors when used simultaneously with clopidogrel has not yet been investigated in adequately randomized studies. Regulatory agencies state that the combination of clopidogrel and the CYP2C19 inhibitors omeprazole and esomeprazole should be avoided. To date, there is no conclusive evidence of a clinically-relevant interaction between any of the proton pump inhibitors and clopidogrel.

  16. Proton diet for the sodium pump.

    Science.gov (United States)

    Apell, Hans-Jürgen; Benz, Gabriela; Sauerbrunn, Daniel

    2011-01-25

    In the absence of Na(+) and K(+) ions the Na,K-ATPase shows a pH-dependent ATP hydrolysis that can be inhibited by ouabain. At pH 7.2 this activity is 5% of the maximal under physiological conditions. It could be inferred that this activity is associated with H(+) transport in both directions across the membrane and facilitates an H-only mode of the sodium pump under such unphysiological conditions. By the analysis of experiments with reconstituted proteoliposomes an overall electroneutral transport mode has been proven. The stoichiometry was determined to be 2 H(+)/2 H(+)/1 ATP and is comparable to what is known from the closely related H,K-ATPase. By time-resolved ATP-concentration jump experiments it was found that at no time was the third, Na(+)-specific binding site of the pump occupied by protons. A modified Post-Albers pump cycle is proposed, with H(+) ions as congeners for Na(+) and K(+), by which all experiments performed can be explained.

  17. Proton Pump Inhibitor Use and the Antifracture Efficacy of Alendronate

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Eiken, Pia Agnete; Eastell, Richard

    2011-01-01

    Background: Proton pump inhibitors (PPIs) are widely used in elderly patients and are frequently coadministered in users of oral bisphosphonates. Biologically, PPIs could affect the absorption of calcium, vitamin B12, and bisphosphonates and could affect the osteoclast proton pump, thus interacting...

  18. The safety of proton pump inhibitors in pregnancy

    DEFF Research Database (Denmark)

    Nielsen, Gunnar Lauge; Sørensen, Henrik Toft; Thulstrup, Ane Marie

    1999-01-01

    AIM: To assess the safety of proton pump inhibitors during pregnancy. METHODS: Fifty-one pregnant women exposed to proton pump inhibitors around the time of conception or during pregnancy were compared with 13 327 controls without exposure to any prescribed drug in a population-based study based...... on The Pharmaco-Epidemiological Prescription Database of North Jutland and the Danish Hospital Discharge Registry. RESULTS: Three babies with malformations were found among 38 women exposed to proton pump inhibitors from 30 days before conception to the end of the first trimester. No cases of stillbirth were...... birth weight or number of preterm deliveries in pregnancies exposed to proton pump inhibitors. However, further monitoring is warranted in order to establish or rule out a potential association between the use of proton pump inhibitors and increased risk of either cardiac malformations or preterm birth....

  19. Strategies for discontinuation of proton pump inhibitors

    DEFF Research Database (Denmark)

    Haastrup, Peter; Paulsen, Maja S; Begtrup, Luise M

    2014-01-01

    and ongoing studies. A total of 371 abstracts were scrutinized to determine relevancy. RESULTS: The thorough search resulted in six clinical studies on strategies for discontinuation of PPIs. All discontinuation regimens used in the studies differed, and several interventions have been tested in order...... to decrease use of PPIs. Discontinuations were reported across all studies ranging from 14% to 64% without deteriorating symptom control. Tapering seems to be a more effective discontinuation strategy than abrupt discontinuation. CONCLUSION: Discontinuation of PPIs is feasible in a clinical setting......PURPOSE: Proton pump inhibitors (PPIs) are considered to be overprescribed. Consensus on how to attempt discontinuation is, however, lacking. We therefore conducted a systematic review of clinical studies on discontinuation of PPIs. METHODS: Systematic review based on clinical studies investigating...

  20. Proton Pump Inhibitors: Risk for Myopathy?

    Science.gov (United States)

    Colmenares, Evan W; Pappas, Ashley L

    2016-08-18

    The purpose of this article is to describe the relationship between proton pump inhibitors (PPIs) and symptoms of myopathy based on case reports. A literature search was conducted in PubMed (1946 to June 2016) using MeSH terms proton pump inhibitors, omeprazole, esomeprazole, lansoprazole, dexlansoprazole, rabeprazole, pantoprazole, and muscular diseases Additionally, a search was conducted in ToxNet and EMBASE using similar search criteria. The resulting articles were scanned to assess relevance to the review. Bibliographies of all relevant articles were evaluated for additional sources; 26 articles resulted from the search of PubMed, ToxNet, and EMBASE; articles that involved medications typically considered to have myalgia-like side effects (eg, statins), or included patients who presented with a confounding disease state (eg, Guillain-Barré) were excluded. In total, 11 case reports as well as a review of an adverse event reporting database that included 292 cases were evaluated. Association of PPI use and myopathy symptoms does not have a clear etiology. Overall, the available published data do not show a high risk of myopathy with PPI use but should be considered if a patient presents with myopathy symptoms and concurrent PPI use. A limited body of published data suggests that PPI use has been associated with myopathy-like symptoms without long-term effects following discontinuation. Although myopathy is a rare adverse effect observed with PPIs, it can be a serious side effect to be considered when starting a patient on acid suppression therapy. © The Author(s) 2016.

  1. Towards structural and functional analysis of the plant plasma membrane proton pump

    DEFF Research Database (Denmark)

    Justesen, Bo Højen

    The plasma membrane H+-ATPase is a proton pump essential for several physiological important processes in plants. Through the extrusion of protons from the cell, the PM H+-ATPase establishes and maintains a proton gradient used by proton coupled transporters and secondary active transport...... of nutrients and metabolites across the plasma membrane. Additional processes involving the PM H+-ATPase includes plant growth, development, and response to biotic and abiotic stresses. Extensive efforts have been made in attempts to elucidate the detailed physiological role and biochemical characteristics...... of plasma membrane H+-ATPases. Studies on the plasma membrane H+-ATPases have involved both in vivo and in vitro approaches, with the latter employing either solubilisation by detergent micelles, or reconstitution into lipid vesicles. Despite resulting in a large body of information on structure, function...

  2. Proton Pump Inhibitors in Pediatrics: Relevant Pharmacokinetics and Pharmacodynamics

    National Research Council Canada - National Science Library

    Kearns, Gregory L; Winter, Harland S

    2003-01-01

    A marked discordance between the disposition of proton pump inhibitors (PPIs) in plasma and the kinetics of effect suggests the need for new approaches to characterize the clinical pharmacology of PPIs in infants and children...

  3. Respiratory Complex I in Bos taurus and Paracoccus denitrificans Pumps Four Protons across the Membrane for Every NADH Oxidized.

    Science.gov (United States)

    Jones, Andrew J Y; Blaza, James N; Varghese, Febin; Hirst, Judy

    2017-03-24

    Respiratory complex I couples electron transfer between NADH and ubiquinone to proton translocation across an energy-transducing membrane to support the proton-motive force that drives ATP synthesis. The proton-pumping stoichiometry of complex I (i.e. the number of protons pumped for each two electrons transferred) underpins all mechanistic proposals. However, it remains controversial and has not been determined for any of the bacterial enzymes that are exploited as model systems for the mammalian enzyme. Here, we describe a simple method for determining the proton-pumping stoichiometry of complex I in inverted membrane vesicles under steady-state ADP-phosphorylating conditions. Our method exploits the rate of ATP synthesis, driven by oxidation of NADH or succinate with different sections of the respiratory chain engaged in catalysis as a proxy for the rate of proton translocation and determines the stoichiometry of complex I by reference to the known stoichiometries of complexes III and IV. Using vesicles prepared from mammalian mitochondria (from Bos taurus) and from the bacterium Paracoccus denitrificans, we show that four protons are pumped for every two electrons transferred in both cases. By confirming the four-proton stoichiometry for mammalian complex I and, for the first time, demonstrating the same value for a bacterial complex, we establish the utility of P. denitrificans complex I as a model system for the mammalian enzyme. P. denitrificans is the first system described in which mutagenesis in any complex I core subunit may be combined with quantitative proton-pumping measurements for mechanistic studies. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  4. Proton pump inhibitors affect the gut microbiome.

    Science.gov (United States)

    Imhann, Floris; Bonder, Marc Jan; Vich Vila, Arnau; Fu, Jingyuan; Mujagic, Zlatan; Vork, Lisa; Tigchelaar, Ettje F; Jankipersadsing, Soesma A; Cenit, Maria Carmen; Harmsen, Hermie J M; Dijkstra, Gerard; Franke, Lude; Xavier, Ramnik J; Jonkers, Daisy; Wijmenga, Cisca; Weersma, Rinse K; Zhernakova, Alexandra

    2016-05-01

    Proton pump inhibitors (PPIs) are among the top 10 most widely used drugs in the world. PPI use has been associated with an increased risk of enteric infections, most notably Clostridium difficile. The gut microbiome plays an important role in enteric infections, by resisting or promoting colonisation by pathogens. In this study, we investigated the influence of PPI use on the gut microbiome. The gut microbiome composition of 1815 individuals, spanning three cohorts, was assessed by tag sequencing of the 16S rRNA gene. The difference in microbiota composition in PPI users versus non-users was analysed separately in each cohort, followed by a meta-analysis. 211 of the participants were using PPIs at the moment of stool sampling. PPI use is associated with a significant decrease in Shannon's diversity and with changes in 20% of the bacterial taxa (false discovery rate microbiome of PPI-users, including the genus Rothia (p=9.8×10(-38)). In PPI users we observed a significant increase in bacteria: genera Enterococcus, Streptococcus, Staphylococcus and the potentially pathogenic species Escherichia coli. The differences between PPI users and non-users observed in this study are consistently associated with changes towards a less healthy gut microbiome. These differences are in line with known changes that predispose to C. difficile infections and can potentially explain the increased risk of enteric infections in PPI users. On a population level, the effects of PPI are more prominent than the effects of antibiotics or other commonly used drugs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  5. Exploring the proton pump and exit pathway for pumped protons in cytochrome ba3 from Thermus thermophilus

    Science.gov (United States)

    Chang, Hsin-Yang; Choi, Sylvia K.; Vakkasoglu, Ahmet Selim; Chen, Ying; Hemp, James; Fee, James A.; Gennis, Robert B.

    2012-01-01

    The heme-copper oxygen reductases are redox-driven proton pumps. In the current work, the effects of mutations in a proposed exit pathway for pumped protons are examined in the ba3-type oxygen reductase from Thermus thermophilus, leading from the propionates of heme a3 to the interface between subunits I and II. Recent studies have proposed important roles for His376 and Asp372, both of which are hydrogen-bonded to propionate-A of heme a3, and for Glu126II (subunit II), which is hydrogen-bonded to His376. Based on the current results, His376, Glu126II, and Asp372 are not essential for either oxidase activity or proton pumping. In addition, Tyr133, which is hydrogen-bonded to propionate-D of heme a3, was also shown not to be essential for function. However, two mutations of the residues hydrogen-bonded to propionate-A, Asp372Ile and His376Asn, retain high electron transfer activity and normal spectral features but, in different preparations, either do not pump protons or exhibit substantially diminished proton pumping. It is concluded that either propionate-A of heme a3 or possibly the cluster of groups centered about the conserved water molecule that hydrogen-bonds to both propionates-A and -D of heme a3 is a good candidate to be the proton loading site. PMID:22431640

  6. Exploring the proton pump and exit pathway for pumped protons in cytochrome ba3 from Thermus thermophilus.

    Science.gov (United States)

    Chang, Hsin-Yang; Choi, Sylvia K; Vakkasoglu, Ahmet Selim; Chen, Ying; Hemp, James; Fee, James A; Gennis, Robert B

    2012-04-03

    The heme-copper oxygen reductases are redox-driven proton pumps. In the current work, the effects of mutations in a proposed exit pathway for pumped protons are examined in the ba(3)-type oxygen reductase from Thermus thermophilus, leading from the propionates of heme a(3) to the interface between subunits I and II. Recent studies have proposed important roles for His376 and Asp372, both of which are hydrogen-bonded to propionate-A of heme a(3), and for Glu126(II) (subunit II), which is hydrogen-bonded to His376. Based on the current results, His376, Glu126(II), and Asp372 are not essential for either oxidase activity or proton pumping. In addition, Tyr133, which is hydrogen-bonded to propionate-D of heme a(3), was also shown not to be essential for function. However, two mutations of the residues hydrogen-bonded to propionate-A, Asp372Ile and His376Asn, retain high electron transfer activity and normal spectral features but, in different preparations, either do not pump protons or exhibit substantially diminished proton pumping. It is concluded that either propionate-A of heme a(3) or possibly the cluster of groups centered about the conserved water molecule that hydrogen-bonds to both propionates-A and -D of heme a(3) is a good candidate to be the proton loading site.

  7. Pancreatic bicarbonate secretion involves two proton pumps

    DEFF Research Database (Denmark)

    Novak, Ivana; Wang, Jing; Henriksen, Katrine L.

    2011-01-01

    H(+)/HCO(3)(-) transporters, which depend on gradients created by the Na(+)/K(+)-ATPase. However, the model cannot fully account for high-bicarbonate concentrations, and other active transporters, i.e. pumps, have not been explored. Here we show that pancreatic ducts express functional gastric...... and non-gastric H(+)-K(+)-ATPases. We measured intracellular pH and secretion in small ducts isolated from rat pancreas and showed their sensitivity to H(+)-K(+) pump inhibitors and ion substitutions. Gastric and non-gastric H(+)-K(+) pumps were demonstrated on RNA and protein levels, and pumps were...... localized to the plasma membranes of pancreatic ducts. Quantitative analysis of H(+)/HCO(3)(-) and fluid transport shows that the H(+)-K(+) pumps can contribute to pancreatic secretion in several species. Our results call for revision of the bicarbonate transport physiology in pancreas, and most likely...

  8. Crystal structure of the plasma membrane proton pump

    DEFF Research Database (Denmark)

    Pedersen, Bjørn P.; Buch-Pedersen, Morten Jeppe; Morth, J. Preben

    2007-01-01

    A prerequisite for life is the ability to maintain electrochemical imbalances across biomembranes. In all eukaryotes the plasma membrane potential and secondary transport systems are energized by the activity of P-type ATPase membrane proteins: H1-ATPase (the proton pump) in plants and fungi1......-3, and Na1,K1-ATPase (the sodium-potassium pump) in animals4. The name P-type derives from the fact that these proteins exploit a phosphorylated reaction cycle intermediate of ATP hydrolysis5.The plasma membrane proton pumps belong to the type III P-type ATPase subfamily, whereas Na1,K1-ATPase and Ca21...... the functional unit of ATP-coupled proton transport across the plasma membrane, and the structure is locked in a functional state not previously observed in P-type ATPases. The transmembrane domain reveals a large cavity, which is likely to be filled with water, located near the middle of the membrane plane...

  9. Use of antacids, alginates and proton pump inhibitors

    DEFF Research Database (Denmark)

    Lødrup, Anders; Reimer, Christine; Bytzer, Peter

    2014-01-01

    OBJECTIVE: Both over-the-counter medicine, such as antacids or alginates, and proton pump inhibitors (PPI) are used for treating acid-related disorders. We sought to describe what characterizes users of these different medicines, including long-term PPI users within the general population. METHOD...

  10. Use of proton pump inhibitors and the risk of listeriosis

    DEFF Research Database (Denmark)

    Jensen, Anne Kvistholm; Simonsen, Jacob; Ethelberg, Steen

    2017-01-01

    BACKGROUND: Recent studies suggest that proton pump inhibitors (PPIs) may increase the risk for listeriosis. We aimed to investigate a potential association in cases of non-pregnancy associated listeriosis, using registry data. METHODS: We conducted a population-based case-control study using...

  11. [Pharmacogenic osteoporosis beyond cortisone. Proton pump inhibitors, glitazones and diuretics].

    Science.gov (United States)

    Kann, P H; Hadji, P; Bergmann, R S

    2014-05-01

    [corrected] There are many drugs which can cause osteoporosis or at least favor its initiation. The effect of hormones and drugs with antihormonal activity, such as glucocorticoids and aromatase inhibitors, on initiation of osteoporosis is well known. In addition, proton pump inhibitors, glitazones and diuretics also influence the formation of osteoporosis. The results of currently available studies on the correlation between proton pump inhibitors, glitazones and diuretics on formation of osteoporosis were evaluated and summarized. Proton pump inhibitors and glitazones increase the risk for osteoporotic fractures. Loop diuretics may slightly increase fracture risk, whereas thiazides were shown to be osteoprotective by reducing fracture probability on a relevant scale. Proton pump inhibitors should not be prescribed without serious consideration and then only as long as necessary. Alternatively, the administration of the less effective H2 antagonists should be considered when possible due to the reduction of acid secretion. Because the long-term intake of thiazides is associated with a clinically relevant reduction in the risk of fractures and they are economic and well-tolerated, prescription can be thoroughly recommended within the framework of differential diagnostic considerations in an appropriate clinical context. The briefly increased risk of falling immediately after starting diuretic therapy is the only point which needs to be considered.

  12. Inappropriate prescribing of proton pump inhibitors among patients ...

    African Journals Online (AJOL)

    non-ICU, who were receiving PPIs prescriptions as part of their drug regimen during their hospitalization, were recruited. ... Keywords: NSAID-induced ulcer, Overuse of medications, Proton pump inhibitor, Stress ulcer,. Intensive care unit .... Patients with uninvestigated dyspepsia may be given full dose PPIs for one month to ...

  13. [Proton pump inhibitors: not as safe as they seem

    NARCIS (Netherlands)

    Herwaarden, N. van; Bos, J.M; Veldman, B.; Kramers, C.

    2016-01-01

    - Proton pump inhibitors (PPIs) are among the most widely used drugs worldwide. However, some patients use them without a good indication.- Although PPIs are generally safe, there is an increasing number of signals of potentially serious side effects.- This article gives an overview of the incidence

  14. Proton pump inhibitors: potential cost reductions by applying prescribing guidelines.

    LENUS (Irish Health Repository)

    Cahir, Caitriona

    2012-01-01

    There are concerns that proton pump inhibitors (PPI) are being over prescribed in both primary and secondary care. This study aims to establish potential cost savings in a community drug scheme for a one year period according to published clinical and cost-effective guidelines for PPI prescribing.

  15. Effectiveness of ranitidine bismuth citrate and proton pump inhibitor ...

    African Journals Online (AJOL)

    A national meta-analysis showed that the average H. pylori eradication rate with proton pump inhibitor-based triple regimens in Turkey had decreased from 84% in 1997 to 55.3% in 2004, suggesting a need to evaluate alternative regimens. Materials and methods: The study was a prospective, single-center trial with a ...

  16. Inappropriate prescribing of proton pump inhibitors among patients ...

    African Journals Online (AJOL)

    Purpose: To evaluate the current prescription pattern and appropriateness of proton pump inhibitors (PPIs) in two of the largest tertiary hospitals in Jordan, and also to determine their utilization rate among the admitted patients. Methods: A retrospective cross-sectional study was conducted over 10 months ...

  17. pH-induced proton permeability changes of plasma membrane vesicles

    NARCIS (Netherlands)

    Miedema, H; Prins, HBA; Staal, H.

    In vivo studies with leaf cells of aquatic plant species such as Elodea nuttallii revealed the proton permeability and conductance of the plasma membrane to be strongly pH dependent. The question was posed if similar pH dependent permeability changes also occur in isolated plasma membrane vesicles.

  18. Increased risk of fundic gland polyps during long-term proton pump inhibitor therapy

    NARCIS (Netherlands)

    Jalving, M.; Koornstra, J. J.; Wesseling, J.; Boezen, H. M.; De Jong, S.; Kleibeuker, J. H.

    2006-01-01

    Background It is controversial whether proton pump inhibitor use leads to fundic gland polyp development. Aim To determine whether fundic gland polyp development is due to proton pump inhibitor use and to investigate mechanisms involved. Methods Proton pump inhibitor use and the presence of fundic

  19. A systematic review of the role of proton pump inhibitors for symptoms of laryngopharyngeal reflux

    NARCIS (Netherlands)

    Sen, P.; Georgalas, C.; Bhattacharyya, A. K.

    2006-01-01

    . Proton pump inhibitors are currently used widely for the treatment of laryngopharyngeal reflux. . This systematic review assessed the efficacy of proton pump inhibitors in the treatment of symptoms of laryngopharyngeal reflux. . Outcome measures used to assess efficacy of proton pump inhibitors

  20. Sodium and proton effects on inward proton transport through Na/K pumps.

    Science.gov (United States)

    Mitchell, Travis J; Zugarramurdi, Camila; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

    2014-06-17

    The Na/K pump hydrolyzes ATP to export three intracellular Na (Nai) as it imports two extracellular K (Ko) across animal plasma membranes. Within the protein, two ion-binding sites (sites I and II) can reciprocally bind Na or K, but a third site (site III) exclusively binds Na in a voltage-dependent fashion. In the absence of Nao and Ko, the pump passively imports protons, generating an inward current (IH). To elucidate the mechanisms of IH, we used voltage-clamp techniques to investigate the [H]o, [Na]o, and voltage dependence of IH in Na/K pumps from ventricular myocytes and in ouabain-resistant pumps expressed in Xenopus oocytes. Lowering pHo revealed that Ho both activates IH (in a voltage-dependent manner) and inhibits it (in a voltage-independent manner) by binding to different sites. Nao effects depend on pHo; at pHo where no Ho inhibition is observed, Nao inhibits IH at all concentrations, but when applied at pHo that inhibits pump-mediated current, low [Na]o activates IH and high [Na]o inhibits it. Our results demonstrate that IH is a property inherent to Na/K pumps, not linked to the oocyte expression environment, explains differences in the characteristics of IH previously reported in the literature, and supports a model in which 1), protons leak through site III; 2), binding of two Na or two protons to sites I and II inhibits proton transport; and 3), pumps with mixed Na/proton occupancy of sites I and II remain permeable to protons. Copyright © 2014 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  1. Proton pumping in cytochrome c oxidase: energetic requirements and the role of two proton channels.

    Science.gov (United States)

    Blomberg, Margareta R A; Siegbahn, Per E M

    2014-07-01

    Cytochrome c oxidase is a superfamily of membrane bound enzymes catalyzing the exergonic reduction of molecular oxygen to water, producing an electrochemical gradient across the membrane. The gradient is formed both by the electrogenic chemistry, taking electrons and protons from opposite sides of the membrane, and by proton pumping across the entire membrane. In the most efficient subfamily, the A-family of oxidases, one proton is pumped in each reduction step, which is surprising considering the fact that two of the reduction steps most likely are only weakly exergonic. Based on a combination of quantum chemical calculations and experimental information, it is here shown that from both a thermodynamic and a kinetic point of view, it should be possible to pump one proton per electron also with such an uneven distribution of the free energy release over the reduction steps, at least up to half the maximum gradient. A previously suggested pumping mechanism is developed further to suggest a reason for the use of two proton transfer channels in the A-family. Since the rate of proton transfer to the binuclear center through the D-channel is redox dependent, it might become too slow for the steps with low exergonicity. Therefore, a second channel, the K-channel, where the rate is redox-independent is needed. A redox-dependent leakage possibility is also suggested, which might be important for efficient energy conservation at a high gradient. A mechanism for the variation in proton pumping stoichiometry over the different subfamilies of cytochrome oxidase is also suggested. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Overuse of proton pump inhibitors and its consequences

    Directory of Open Access Journals (Sweden)

    Marcin Kazberuk

    2016-10-01

    Full Text Available Direct inhibition of H+ ion excretion to the gastric lumen makes proton pump inhibitors (PPI the most effective drugs against gastric acid-related diseases. Over recent years usage of proton pump inhibitors has increased dramatically. Due to the low costs, high efficacy and rarity of adverse effects, their use is prevalent and often it does not correspond with existing medical guidelines. The literature lists stress ulcer prophylaxis among patients with low risk of bleeding, routine ‘gastroprotective’ medication during treatment and non-specific abdominal symptoms as the most common patterns of off-label PPI use. This article summarizes the influence of PPI therapy on gastric mucosa, absorption and occurrence of adverse effects. The authors note that their low awareness among physicians contributes to wide and imprudent use of drugs of this group.

  3. Plant proton pumps as markers of biostimulant action

    Directory of Open Access Journals (Sweden)

    Daniel Basílio Zandonadi

    2016-02-01

    Full Text Available ABSTRACT A standard protocol to evaluate the effects of biostimulants on plant physiology is still lacking. The proton pumps present in the vacuolar and plasma membranes are the primary agents responsible for the regulation of the electrochemical gradient that energizes the nutrient uptake system and acid growth mechanism of plant cells. In this study, two of these enzymes were characterized as biochemical markers of biostimulant activity. A simple and fast protocol based on the degree of root acidification using a pH sensitive dye and the Micro-Tom tomato as a plant model is proposed as an efficient methodology to prove the efficacy of biostimulants that are claimed to improve nutrient acquisition and root growth. The results agree with the data from more conventional, expensive and time-consuming proton pump assays. A direct correlation was found between plasmalemma proton-adenosine triphosphatase (H+-ATPase activation and the amount of rhizosphere acidification observed in the bromocresol gel. Moreover, roots of the diageotropica (dgt Micro-Tom plants, defective in auxin responses, barely acidify bromocresol purple gel even in the presence of indole-3-acetic acid (IAA, 1 μM. The biostimulant TEA (vermicompost water extract, 25 % enhances proton extrusion by 40 % in wild type (WT plants, but no effect was induced in dgt plants. These results reinforce the notion that the class of biostimulant known as humic substances stimulates plant proton pumps and promotes root growth by exerting an auxin-like bioactivity and establish the usefulness of an economically and technically feasible assay to certify this kind of biostimulant.

  4. Dietary Inulin Fibers Prevent Proton-Pump Inhibitor (PPI)-Induced Hypocalcemia in Mice

    NARCIS (Netherlands)

    Hess, M.W.; Baaij, J.H.F. de; Gommers, L.M.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2015-01-01

    BACKGROUND: Proton-pump inhibitor-induced hypomagnesemia (PPIH) is the most recognized side effect of proton-pump inhibitors (PPIs). Additionally, PPIH is associated with hypocalcemia and hypokalemia. It is hypothesized that PPIs reduce epithelial proton secretion and thereby increase the pH in the

  5. Use of proton pump inhibitors during pregnancy and breastfeeding.

    Science.gov (United States)

    Nava-Ocampo, Alejandro A; Velázquez-Armenta, Elvia Y; Han, Jung-Yeol; Koren, Gideon

    2006-07-01

    A 36-year-old pregnant patient has symptoms of peptic disease. Treatment with diet and lifestyle modifications and also antacids has given her little relief. If she were not pregnant, I would prescribe a proton pump inhibitor (PPI) for her. She is now 4 weeks pregnant, and I need to determine whether PPIs are safe during pregnancy. Data currently available suggest that omeprazole is not teratogenic in humans. While information on other PPIs is limited, a systematic review of the evidence suggests that they are also not teratogenic.

  6. Proton pump inhibitor usage and the associated risk of pneumonia in patients with chronic kidney disease

    National Research Council Canada - National Science Library

    Chen, Chih-Hung; Lin, Hsiu-Chen; Lin, Hsiu-Li; Lin, Yi-Tsung; Chou, Jung-Min; Hsu, Shih-Ping; Fung, Chang-Phone

    2015-01-01

    .... Gastrointestinal symptoms frequently occur in patients with CKD, and proton pump inhibitors (PPIs) have therapeutic indications for gastrointestinal disorders involving excessive acid production...

  7. Association Between Proton Pump Inhibitors and Microscopic Colitis.

    Science.gov (United States)

    Law, Ernest H; Badowski, Melissa; Hung, Yu-Ting; Weems, Kimberly; Sanchez, Angelica; Lee, Todd A

    2017-03-01

    Microscopic colitis (MC) is a chronic inflammatory disease of the colon that is characterized by chronic, watery, nonbloody diarrhea. Concern regarding a potential association between proton-pump inhibitors (PPIs) and MC has recently emerged. We sought to systematically review and summarize the evidence for the potential association between PPIs and MC. We systematically searched EMBASE, MEDLINE, Cochrane Database of Systematic Reviews, International Pharmaceutical Abstracts, and Google Scholar using the terms proton-pump inhibitors (omeprazole, lansoprazole, dexlansoprazole, rabeprazole, pantoprazole, or esomeprazole), microscopic colitis, collagenous colitis, and lymphocytic colitis. Full-text, English-language reports of case reports/series, observational studies, experimental studies, and systematic reviews/meta-analyses published between January 2000 to August 2016 were included. Bibliographies from pertinent publications were reviewed for additional references. Outcome was defined as the development of biopsy-confirmed MC. A total of 19 publications were identified: 5 case control studies and 14 case reports/series (encompassing a total of 32 cases). All studies were limited by small sample sizes. Risk of MC by dose or specific PPI agent was not investigated in any of the studies. A review of the current body of evidence reveals a possible association between PPIs and MC. There is a need for large observational studies of high quality to examine the differential effect of specific PPIs and whether the magnitude of association is dose dependent. Given their widespread use, clinicians should routinely question whether patients are receiving unnecessary treatment with PPIs and discontinue therapy where appropriate.

  8. Potential interaction between proton pump inhibitor and clopidogrel

    Directory of Open Access Journals (Sweden)

    Indra Kurniawan

    2013-02-01

    Full Text Available Clopidogrel is an anti-platelet agent commonly used in patients with atherosclerotic cardiovascular (CV disease. Although formerly considered safe, several studies reported that the use of clopidogrel may cause a significant increase in the rate of gastrointestinal (GI bleeding. This adverse effect could be minimized by coadministration of proton pump inhibitor (PPI. However, since PPI and clopidogrel share the same metabolic pathway, it has been hypothesized that the administration of PPI following clopidogrel therapy may cause a reduction in its anti-platelet effect, thereby increasing the risk of CV events. Recent studies found no significant inhibition in the activation of clopidogrel by CYP2C19 with administration of PPI in vitro. Pharmacokinetic and pharmacodynamic studies, as well as clinical studies, reported conflicting results regarding the potential interaction between PPI and clopidogrel. Until now, the available study investigated the PPI-clopidogrel interaction are primarily observational. The COGENT study is the only prospective, placebo-controlled trial examined the PPI-clopidogrel interaction. This study revealed no significant increase in CV events in patients receiving PPI following clopidogrel therapy, compared to the control group. Though remains controversial, current expert consensus recommended the administration of PPI in patients receiving clopidogrel, particularly in high-risk patients. (Med J Indones. 2013;22:57-62Keywords: Cardiovascular, clopidogrel, gastrointestinal, proton pump inhibitor

  9. Subunit composition and ATP site labeling of the coated vesicle proton-translocating adenosinetriphosphatase

    Energy Technology Data Exchange (ETDEWEB)

    Arai, H.; Berne, M.; Terres, G.; Terres, H.; Puopolo, K.; Forgac, M.

    1987-10-20

    The partially purified proton-translocating adenosinetriphosphatase ((H/sup +/)-ATPase) from clathrin-coated vesicles has been reported to contain eight polypeptides of molecular weights 15,000-116,000. To determine whether these polypeptides form a single macromolecular complex, the authors have isolated three monoclonal antibodies which recognize the reconstitutively active (H/sup +/)-ATPase in the native, detergent-solubilized state. All three monoclonal antibodies precipitate the same set of polypeptides from either the partially purified enzyme or the detergent-solubilized coated vesicle membrane proteins. The immunoprecipitated polypeptides have molecular weights of 100,000, 73,000, 58,000, 40,000, 38,000, 34,000, 33,000, 19,000, and 17,000. These results thus indicate that this set of polypeptides forms a single macromolecular complex and suggest that they correspond to subunits of the coated vesicle (H/sup +/)-ATPase. To identify the ATP-hydrolytic subunit of the coated vesicle (H/sup +/)-ATPase, the purified enzyme was reacted with N-ethylmaleimide (NEM) and 7-chloro-4-nitro-2,1,3-benzoxadiazole (NBD-C1), both of which inhibit activity in an ATP-protectable manner. Labeling was carried out by using (/sup 3/H)NEM or (/sup 14/C)NBD-C1, and the specificity of the reaction was increased by prelabeling of the protein with the nonradioactive reagents in the presence of ATP and by taking advantage of the nucleotide specificity of protection. The principal polypeptide labeled by both (/sup 3/H)NEM and (/sup 14/C)NBD-C1 had a molecular weight of 73,000. In addition, this protein was the only polypeptide whose labeling was significantly reduced in the presence of ATP. These results suggest that the 73,000-dalton polypeptide participates in ATP hydrolysis by the coated vesicle (H/sup +/)-ATPase.

  10. The appropriateness of a proton pump inhibitor prescription.

    LENUS (Irish Health Repository)

    Moran, N

    2014-11-01

    Proton pump inhibitors (PPIs) are one of the most commonly prescribed groups of drug in Ireland, at great expense to the Irish healthcare executive. This study aims to evaluate the appropriateness of PPI prescriptions on admission and discharge in a tertiary referral hospital. All non-elective admissions in the Emergency Department in one week were included in the study. 102 patients in total were included, with 36 (35.4%) treated with a PPI on admission. Of these, only 3 (8.3%) had a clear indication noted as per current NICE guidelines. 18 new in-hospital PPI prescriptions were documented. 11 (61%) of which were present on discharge prescriptions. Continuing PPI prescription on discharge into the community may be inappropriate, costly and potentially harmful. Brief interventions aimed at reducing inappropriate PPI prescriptions have been shown to be effective at reducing the cost and potential harm of unnecessary treatment.

  11. Acute interstitial nephritis due to proton pump inhibitors

    Directory of Open Access Journals (Sweden)

    K Sampathkumar

    2013-01-01

    Full Text Available Proton pump inhibitors (PPI are commonly prescribed for dyspepsia and acid peptic disease. Acute interstitial nephritis (AIN is an uncommon though important side-effect of these classes of drugs. We describe four cases: three females and one male. PPIs implicated were pantoprazole in two, omeprazole and esomeprazole in one each. AIN developed after an average period of 4 weeks of drug therapy. The symptoms were vomiting, loin pain, and oliguria. Minimal proteinuria with pyuria were seen and the mean serum creatinine was 4.95 ± 4 mg/dl. Two patients required hemodialysis. Renal biopsy showed interstitial mononuclear, plasma cell and eosinophilic infiltrates in all cases. PPI was stopped and steroids were started in all. Renal recovery was total in two and partial in two. A high index of suspicion is required to diagnose PPI induced AIN. Renal biopsy for confirmation followed up by prompt steroid therapy results in renal functional improvement.

  12. Use of proton pump inhibitors after anti-reflux surgery

    DEFF Research Database (Denmark)

    Lodrup, A.; Pottegård, Anton; Hallas, J.

    2014-01-01

    healthcare registries. Design A nationwide retrospective follow-up study of all patients aged >= 18 and undergoing first-time ARS in Denmark during 1996-2010. Two outcome measures were used: redemption of first PPI prescription after ARS (index prescription) and a marker of long-term use, defined......, respectively. Five-, 10- and 15-year risks of redeeming index PPI prescription were 57.5%, 72.4% and 82.6%, respectively. Similarly, 5-, 10- and 15-year risks of taking up long-term PPI use were 29.4%, 41.1% and 56.6%. Female gender, high age, ARS performed in most recent years, previous use of PPI and use......Objective Antireflux surgery (ARS) has been suggested as an alternative to lifelong use of proton pump inhibitors (PPI) in reflux disease. Data from clinical trials on PPI use after ARS have been conflicting. We investigated PPI use after ARS in the general Danish population using nationwide...

  13. Hypomagnesemia Induced by Long-Term Treatment with Proton-Pump Inhibitors

    Directory of Open Access Journals (Sweden)

    Simone Janett

    2015-01-01

    Full Text Available In 2006, hypomagnesemia was first described as a complication of proton-pump inhibitors. To address this issue, we systematically reviewed the literature. Hypomagnesemia, mostly associated with hypocalcemic hypoparathyroidism and hypokalemia, was reported in 64 individuals on long-term proton-pump inhibitors. Hypomagnesemia recurred following replacement of one proton-pump inhibitor with another but not with a histamine type-2 receptor antagonist. The association between proton-pump inhibitors and magnesium metabolism was addressed in 14 case-control, cross-sectional studies. An association was found in 11 of them: 6 reports found that the use of proton-pump inhibitors is associated per se with a tendency towards hypomagnesemia, 2 found that this tendency is more pronounced in patients concurrently treated with diuretics, carboplatin, or cisplatin, and 2 found a relevant tendency to hypomagnesemia in patients with poor renal function. Finally, findings likely reflecting decreased intestinal magnesium uptake were observed on treatment with proton-pump inhibitors. Three studies did not disclose any relationship between magnesium metabolism and treatment with histamine type-2 receptor antagonists. In conclusion, proton-pump inhibitors may cause hypomagnesemia. In these cases, switching to a histamine type-2 receptor antagonist is advised.

  14. Correlation between proton pump inhibitors and risk of pyogenic liver abscess.

    Science.gov (United States)

    Lin, Hsien-Feng; Liao, Kuan-Fu; Chang, Ching-Mei; Lin, Cheng-Li; Lai, Shih-Wei

    2017-08-01

    Little is known about the relationship between proton pump inhibitors use and pyogenic liver abscess. The objective of this study was to evaluate the correlation between proton pump inhibitors use and pyogenic liver abscess in Taiwan. This was a population-based case-control study using the database of the Taiwan National Health Insurance Program since 2000 to 2011. Subjects aged 20 to 84 who experienced their first episode of pyogenic liver abscess were enrolled as the case group (n = 1372). Randomly selected subjects aged 20 to 84 without pyogenic liver abscess were enrolled as the control group (n = 1372). Current use, early use, and late use of proton pump inhibitors was defined as subjects whose last one tablet for proton pump inhibitors was noted ≤30 days, between 31 to 90 days and ≥91 days before the date of admission for pyogenic liver abscess. Subjects who never received a prescription for proton pump inhibitors were defined as nonusers of proton pump inhibitors. A multivariable unconditional logistic regression model was used to measure the odds ratio and 95% confidence interval to evaluate the correlation between proton pump inhibitors use and pyogenic liver abscess. After adjusting for confounders, the adjusted odds ratio of pyogenic liver abscess was 7.59 for subjects with current use of proton pump inhibitors (95% confidence interval 5.05, 11.4), when compared with nonusers. Current use of proton pump inhibitors is associated with a greater risk of pyogenic liver abscess.

  15. Identification of a high-affinity Ca sup 2+ pump associated with endocytotic vesicles in Dictyostelium discoideum

    Energy Technology Data Exchange (ETDEWEB)

    Milne, J.L.; Coukell, M.B. (York Univ., North York, Ontario (Canada))

    1989-11-01

    In the cellular slime mold Dictyostelium discoideum, changes in free cytosolic Ca{sup 2+} are thought to regulate certain processes during cell aggregation and differentiation. To understand the mechanisms controlling free Ca{sup 2+} levels in this organism, the authors previously isolated and characterized an ATP/Mg{sup 2+}-dependent, high-affinity Ca{sup 2+} pump which appeared to be a component of inside-out plasma membrane vesicles. In this report, they demonstrate that a high-affinity Ca{sup 2+} pump, with properties virtually identical to the isolated pump, can be detected in filipin- or digitonin-permeabilized cells of Dictyostelium. Moreover, Ca{sup 2+}-pumping vesicles, which migrate on Percoll/KCl gradients like the vesicles identified earlier, can be isolated from the permeabilized cells. Results of additional experiments suggest that this intracellular Ca{sup 2+} transporter is associated with a high-capacity non-IP{sub 3}-releasable Ca{sup 2+} store which is generated by endocytosis. A possible role for this store in maintaining Ca{sup 2+} homeostasis in Dictyostelium is discussed.

  16. Proton pump inhibitor therapy and potential long-term harm.

    Science.gov (United States)

    Corleto, Vito Domenico; Festa, Stefano; Di Giulio, Emilio; Annibale, Bruno

    2014-02-01

    This review summarizes the recent literature on the potential side-effects of proton pump inhibitors (PPIs) and known interactions with the metabolism/absorption of other drugs. Data confirm that PPIs are a very well tolerated drug class. Their high safety, efficacy and wide distribution lead to overuse, inappropriate dosage or excessive duration of treatment. Despite the absorption of micronutrients or other plausible effects on the development of bacterial infections linked to PPI-induced hypochlorhydria, it is difficult to demonstrate an association between PPI and specific symptoms. A possible negative effect of PPIs on bone integrity appears weak, but hypomagnesemia is likely a PPI drug class effect. A higher risk of Clostridium difficile infection and other infectious diseases such as small intestinal bacterial overgrowth and spontaneous bacterial peritonitis remain controversial in PPI users. However, the careful use of PPIs in cirrhotic or otherwise fragile patients is mandatory. Short-term or long-term PPI use may trigger microscopic colitis, and the management of this condition may include PPI withdrawal. The effect of PPIs on stimulating exocrine or endocrine gastric cell proliferation is poorly understood. A diagnostic delay or masking of diseases such as gastrinoma is difficult to evaluate. Short-term standard dose PPI treatment is low risk. Long-term PPI use may complicate health conditions by various mechanisms linked to PPIs and/or to hypochlorhydria.

  17. Proton pump inhibitors as a risk factor for norovirus infection.

    Science.gov (United States)

    Prag, C; Prag, M; Fredlund, H

    2017-06-01

    Norovirus causes viral gastroenteritis, which is a major problem in health care. The disease causes death in elderly and seriously ill patients, and results in significant health costs each year. Proton pump inhibitors (PPIs) reduce gastric acidity, which is an important protection against microorganisms. We hypothesised that treatment with PPIs increases the risk of contracting norovirus infection. This has not previously been studied. The study was a retrospective case-control study, in which 192 hospitalised patients positive for norovirus in Örebro County, Sweden, were identified as cases. For each case, a hospitalised patient who did not have the infection was selected as a control, and matched with respect to ward, gender, admission date and age. Details of exposure, i.e. treatment with PPIs, were retrieved from the patient records. Odds ratio (OR) with confidence intervals (CIs) and P-values were calculated using McNemar's test. There was a significantly increased risk of norovirus infection in patients treated with PPIs compared with patients without PPI treatment (OR 1·73, 95% CI 1·07-2·81; P = 0·02). PPIs appear to be a risk factor for norovirus infection, and our results motivate future studies to further examine this association.

  18. Implementation of a proton pump inhibitor stewardship program.

    Science.gov (United States)

    Davis, Kelly W; Hanners, Rachel E; Lockwood, Sean M

    2017-06-15

    The development and implementation of a proton pump inhibitor (PPI) stewardship program at a single institution are described. Due to the overuse of PPIs and the increasing awareness of the adverse drug events associated with long-term PPI therapy, the pharmacy and internal medicine services of a medical center implemented a PPI stewardship program. All patients admitted to the internal medicine service were evaluated by the PPI stewardship team to determine if they had an appropriate indication for PPI continuation in the hospital as well as after discharge. If patients did not meet specified criteria for continuation of PPI use during hospitalization, PPI therapy was suspended and replaced by as-needed acid suppressive therapy, and the patients received discharge counseling regarding the implemented medication regimen changes. Challenges encountered during program development included establishing appropriate criteria for PPI continuation and determining the best method for discontinuing PPIs in order to reduce the risk of rebound hyperacidity. In an effort to reduce unnecessary PPI use, a PPI stewardship program was developed and implemented to ensure appropriate continuation of PPIs for patients admitted and discharged from an internal medicine service. Copyright © 2017 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

  19. Proton pump inhibitor use in a university teaching hospital

    Directory of Open Access Journals (Sweden)

    Maria Meli

    2012-10-01

    Full Text Available Introduction Proton pump inhibitors (PPIs are highly prescribed drugs in Italy and in particular in the Sicilian region but little is known about their use in the hospital setting.Materials and methods PPI utilization and related costs were reviewed retrospectively by examining the pharmaceutical records of drug dispensation to the various wards of the Policlinico Universitario P. Giaccone of Palermo in 2010. Differences in the prescribing rates and drug preferences among the different clinical wards were analyzed.Results A total of 20,420 patients were hospitalized at the Policlinico of Palermo in 2010. Overall, the consumption of PPIs was 120 DDD/100 bed-days for the year 2010 with a total cost of 42,780 euros. Omeprazole and esomeprazole were the most commonly prescribed molecules accounting for over 70% of all prescriptions: nevertheless, wide differences in drug choices were noted even within the same ward. As expected, greater utilization rates were registered in the Internal Medicine and General Surgery departments. In particular, the highest consumption was observed in the Oncology, Geriatry and Obesity Surgery wards, with about 250 DDD/100 bed-days. All wards reported intravenous PPI administration suggesting some inappropriate use.Discussion From our data, PPIs appear to be moderately over-used at the Policlinico of Palermo. This practice may lead to the inappropriate continuation of therapy in primary care, further increasing costs and risks of adverse events. A survey evaluating in more detail the appropriateness of prescriptions is advisable.

  20. Association Between Proton Pump Inhibitor Use and Spontaneous Bacterial Peritonitis in Cirrhotic Patients with Ascites

    Directory of Open Access Journals (Sweden)

    Mélissa Ratelle

    2014-01-01

    Full Text Available BACKGROUND: There are data suggesting a link between proton pump inhibitor (PPI use and the development of spontaneous bacterial peritonitis (SBP in cirrhotic patients with ascites; however, these data are controversial.

  1. Differences in proton pumping and Na/H exchange at the leaf cell tonoplast between a halophyte and a glycophyte

    Science.gov (United States)

    Katschnig, Diana; Jaarsma, Rinse; Almeida, Pedro; Rozema, Jelte; Schat, Henk

    2014-01-01

    The tonoplast Na+/H+ antiporter and tonoplast H+ pumps are essential components of salt tolerance in plants. The objective of this study was to investigate the transport activity of the tonoplast Na+/H+ antiporter and the tonoplast V-H+-ATPase and V-H+-PPase in a highly tolerant salt-accumulating halophyte, Salicornia dolichostachya, and to compare these transport activities with activities in the related glycophyte Spinacia oleracea. Vacuolar membrane vesicles were isolated by density gradient centrifugation, and the proton transport and hydrolytic activity of both H+ pumps were studied. Furthermore, the Na+/H+-exchange capacity of the vesicles was investigated by 9-amino-6-chloro-2-methoxyacridine fluorescence. Salt treatment induced V-H+-ATPase and V-H+-PPase activity in vesicles derived from S. oleracea, whereas V-H+-ATPase and V-H+-PPase activity in S. dolichostachya was not affected by salt treatment. Na+/H+-exchange capacity followed the same pattern, i.e. induced in response to salt treatment (0 and 200 mM NaCl) in S. oleracea and not influenced by salt treatment (10 and 200 mM NaCl) in S. dolichostachya. Our results suggest that S. dolichostachya already generates a high tonoplast H+ gradient at low external salinities, which is likely to contribute to the high cellular salt accumulation of this species at low external salinities. At high external salinities, S. dolichostachya showed improved growth compared with S. oleracea, but V-H+-ATPase, V-H+-PPase and Na+/H+-exchange activities were comparable between the species, which might imply that S. dolichostachya more efficiently retains Na+ in the vacuole. PMID:24887002

  2. Allosteric interactions and proton conducting pathways in proton pumping aa(3) oxidases: heme a as a key coupling element.

    Science.gov (United States)

    Capitanio, Nazzareno; Palese, Luigi Leonardo; Capitanio, Giuseppe; Martino, Pietro Luca; Richter, Oliver-Matthias H; Ludwig, Bernd; Papa, Sergio

    2012-04-01

    In this paper allosteric interactions in protonmotive heme aa(3) terminal oxidases of the respiratory chain are dealt with. The different lines of evidence supporting the key role of H(+)/e(-) coupling (redox Bohr effect) at the low spin heme a in the proton pump of the bovine oxidase are summarized. Results are presented showing that the I-R54M mutation in P. denitrificans aa(3) oxidase, which decreases by more than 200mV the E(m) of heme a, inhibits proton pumping. Mutational amino acid replacement in proton channels, at the negative (N) side of membrane-inserted prokaryotic aa(3) oxidases, as well as Zn(2+) binding at this site in the bovine oxidase, uncouples proton pumping. This effect appears to result from alteration of the structural/functional device, closer to the positive, opposite (P) surface, which separates pumped protons from those consumed in the reduction of O(2) to 2 H(2)O. Copyright © 2011 Elsevier B.V. All rights reserved.

  3. Proton pump inhibitors alter the composition of the gut microbiota.

    Science.gov (United States)

    Jackson, Matthew A; Goodrich, Julia K; Maxan, Maria-Emanuela; Freedberg, Daniel E; Abrams, Julian A; Poole, Angela C; Sutter, Jessica L; Welter, Daphne; Ley, Ruth E; Bell, Jordana T; Spector, Tim D; Steves, Claire J

    2016-05-01

    Proton pump inhibitors (PPIs) are drugs used to suppress gastric acid production and treat GI disorders such as peptic ulcers and gastro-oesophageal reflux. They have been considered low risk, have been widely adopted, and are often over-prescribed. Recent studies have identified an increased risk of enteric and other infections with their use. Small studies have identified possible associations between PPI use and GI microbiota, but this has yet to be carried out on a large population-based cohort. We investigated the association between PPI usage and the gut microbiome using 16S ribosomal RNA amplification from faecal samples of 1827 healthy twins, replicating results within unpublished data from an interventional study. We identified a significantly lower abundance in gut commensals and lower microbial diversity in PPI users, with an associated significant increase in the abundance of oral and upper GI tract commensals. In particular, significant increases were observed in Streptococcaceae. These associations were replicated in an independent interventional study and in a paired analysis between 70 monozygotic twin pairs who were discordant for PPI use. We propose that the observed changes result from the removal of the low pH barrier between upper GI tract bacteria and the lower gut. Our findings describe a significant impact of PPIs on the gut microbiome and should caution over-use of PPIs, and warrant further investigation into the mechanisms and their clinical consequences. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  4. Influence of proton pump inhibitor use in gastrointestinal polyps.

    Science.gov (United States)

    Hsu, Wen-Hung; Wu, I-Chen; Kuo, Chao-Hung; Su, Yu-Chung; Lu, Chien-Yu; Kuo, Fu-Chen; Jan, Chang-Ming; Wang, Wen-Ming; Wu, Deng-Chyang; Yu, Fang-Jung

    2010-02-01

    Proton pump inhibitors (PPIs) are the most potent anti-acid agents and are extensively used worldwide. PPI-induced hypergastrinemia is one of the very few side effects associated with these drugs. However, because hypergastrinemia is related to the occurrence of colonic adenomatous polyps, the purpose of this study was to analyze the relationship between the occurrence of gastrointestinal polyps and hypergastrinemia induced by PPIs. This study included 259 patients who underwent colonoscopy and esophagogastroduodenoscopy between January and August 2007. Chart records, including medication history and fasting plasma gastrin level, were reviewed and analyzed. Any subtle polypoid lesions in the stomach and colon were sampled by biopsy for histological examination. Helicobacter pylori infection status was examined by a rapid urea test during esophagogastroduodenoscopy. All patients underwent endoscopy examinations. A total of 122 patients were receiving PPI treatment for either peptic ulcer disease or reflux esophagitis and were included as the study group. The remaining 137 patients were not treated with PPIs and served as the non-PPI group. The mean fasting gastrin level in PPI users versus non-PPI users was 121.8 ng/L versus 56.8 ng/L, respectively (p polyps was higher in the PPI group (65.6% vs. 37.2%, p polyps observed (22.13% vs. 22.62%, p = 0.928). In conclusion, the prevalence of gastric polyps, particularly fundic gland polyps, was higher among PPI users. However, the prevalence of colonic polyps was not affected by PPI use, regardless of past history of colonic adenomatous polyps.

  5. Proton pump inhibitors on pancreatic cancer risk and survival.

    Science.gov (United States)

    Kearns, Malcolm D; Boursi, Ben; Yang, Yu-Xiao

    2017-02-01

    Hypergastrinemia may promote the development and progression of pancreatic cancer. Proton pump inhibitor (PPI) therapy is known to cause hypergastrinemia. We sought to determine the association between PPI therapy and the risk of developing pancreatic cancer as well as survival following pancreatic cancer diagnosis. We conducted a nested case-control study and a retrospective cohort study in The Health Improvement Network (THIN), a medical records database representative of the UK population. In the case-control study, each patient with incident pancreatic cancer was matched with up to four controls based on age, sex, practice site and both duration and calendar time of follow-up using incidence density sampling. The odds ratios (ORs) and 95% confidence intervals (CIs) for pancreatic cancer risk associated with PPI use were estimated using multivariable conditional logistic regression. The retrospective cohort study compared the survival of pancreatic cancer patients according to their PPI exposure at the time of diagnosis. The effect of PPI use on pancreatic cancer survival was assessed using a multivariable Cox regression analysis. The case-control study included 4113 cases and 16,072 matched controls. PPI use was more prevalent in cases than controls (53% vs. 26% active users). Adjusting for diabetes, smoking, alcohol use and BMI, PPI users including both former users and active users with longer cumulative PPI use had a higher risk of pancreatic cancer compared to non-users. When assessing survival following pancreatic cancer diagnosis, only short-term, active users had a modest decrease in survival. Long-term PPI therapy may be associated with pancreatic cancer risk. While PPI users recently started on treatment had a slightly worse survival, this result likely is from reverse causation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Proton pump inhibitors: potential cost reductions by applying prescribing guidelines

    Directory of Open Access Journals (Sweden)

    Cahir Caitriona

    2012-11-01

    Full Text Available Abstract Background There are concerns that proton pump inhibitors (PPI are being over prescribed in both primary and secondary care. This study aims to establish potential cost savings in a community drug scheme for a one year period according to published clinical and cost-effective guidelines for PPI prescribing. Methods Retrospective population-based cohort study in the Republic of Ireland using the Health Services Executive (HSE Primary Care Reimbursement Services (PCRS pharmacy claims database. The HSE-PCRS scheme is means tested and provides free health care including medications to approximately 30% of the Irish population. Prescription items are WHO ATC coded and details of every drug dispensed and claimants’ demographic data are available. Potential cost savings (net ingredient cost were estimated according to UK NICE clinical guidelines for all HSE-PCRS claimants on PPI therapy for ≥3 consecutive months starting in 2007 with a one year follow up (n=167,747. Five scenarios were evaluated; (i change to PPI initiation (cheapest brand; and after 3 months (ii therapeutic switching (cheaper brand/generic equivalent; (iii dose reduction (maintenance therapy; (iv therapeutic switching and dose reduction and (v therapeutic substitution (H2 antagonist. Results Total net ingredient cost was €88,153,174 for claimants on PPI therapy during 2007. The estimated costing savings for each of the five scenarios in a one year period were: (i €36,943,348 (42% reduction; (ii €29,568,475 (34%; (iii €21,289,322 (24%; (iv €40,505,013 (46%; (v €34,991,569 (40%. Conclusion There are opportunities for substantial cost savings in relation to PPI prescribing if implementation of clinical guidelines in terms of generic substitution and step-down therapy is implemented on a national basis.

  7. Proton-pumping mechanism of cytochrome c oxidase: A kinetic master-equation approach

    Science.gov (United States)

    Kim, Young C.; Hummer, Gerhard

    2011-01-01

    Cytochrome c oxidase (CcO) is an efficient energy transducer that reduces oxygen to water and converts the released chemical energy into an electrochemical membrane potential. As a true proton pump, CcO translocates protons across the membrane against this potential. Based on a wealth of experiments and calculations, an increasingly detailed picture of the reaction intermediates in the redox cycle has emerged. However, the fundamental mechanism of proton pumping coupled to redox chemistry remains largely unresolved. Here we examine and extend a kinetic master-equation approach to gain insight into redox-coupled proton pumping in CcO. Basic principles of the CcO proton pump emerge from an analysis of the simplest kinetic models that retain essential elements of the experimentally determined structure, energetics, and kinetics, and that satisfy fundamental physical principles. The master-equation models allow us to address the question of how pumping can be achieved in a system in which all reaction steps are reversible. Whereas proton pumping does not require the direct modulation of microscopic reaction barriers, such kinetic gating greatly increases the pumping efficiency. Further efficiency gains can be achieved by partially decoupling the proton uptake pathway from the ative-site region. Such a mechanism is consistent with the proposed Glu valve, in which the side chain of a key glutamic acid shuttles between the D channel and the active-site region. We also show that the models predict only small proton leaks even in the absence of turnover. The design principles identified here for CcO provide a blueprint for novel biology-inspired fuel cells, and the master-equation formulation should prove useful also for other molecular machines. PMID:21946020

  8. Receptor kinase-mediated control of primary active proton pumping at the plasma membrane

    DEFF Research Database (Denmark)

    Fuglsang, Anja Thoe; Kristensen, Astrid; Cuin, Tracey A.

    2014-01-01

    Acidification of the cell wall space outside the plasma membrane is required for plant growth and is the result of proton extrusion by the plasma membrane-localized H+-ATPases. Here we show that the major plasma membrane proton pumps in Arabidopsis, AHA1 and AHA2, interact directly in vitro...... heterologous expression system, the introduction of a negative charge at this position caused pump activation. Application of PSY1 to plant seedlings induced rapid in planta phosphorylation at Thr-881, concomitant with an instantaneous increase in proton efflux from roots. The direct interaction between AHA2...

  9. ENDOSCOPIC AND HISTOPATHOLOGIC GASTRIC CHANGES IN CHRONIC USERS OF PROTON-PUMP INHIBITORS

    Directory of Open Access Journals (Sweden)

    Sílvia Maria Perrone CAMILO

    2015-03-01

    Full Text Available Background Proton-pump inhibitors have been used for at least two decades. They are among the most commonly sold drugs in the world. However, some controversy remains about the indications for their use and the consequences of their prolonged use. Objectives To evaluate and compare the endoscopic and histopathologic gastric changes in chronic users of proton-pump inhibitors to changes in non-users. Methods A prospective study performed at a tertiary Public Hospital involving 105 patients undergoing upper-gastrointestinal endoscopy. Subjects included 81 proton-pump inhibitor users and 24 non-users (control group. Biopsies of the antral-type mucosa, the antral-fundic transition, and the fundus were evaluated by the Sydney System. The presence of erosion or ulceration, lymphatic follicles, reactive gastropathy, and polypoid or epithelial hyperplasia was also determined. Serum levels of gastrin were measured. Results We found two polyps, one in each group, both of which were negative for Helicobacter pylori. There were two cases of parietal cell hyperplasia in users of proton-pump inhibitors. Gastrin was elevated in 28 users of proton-pump inhibitors and in four members of the control group. We did not find statistically significant differences in the endoscopic or histopathologic findings between the two groups. Conclusions Chronic use of proton-pump inhibitors for the duration examined was not associated with significant gastric changes. An interesting finding was that the 4 chronic users of proton-pump inhibitors who had serum gastrin levels above 500 pg/mL also had positive serology for Chagas disease.

  10. A Conserved Asparagine in a P-type Proton Pump Is Required for Efficient Gating of Protons*

    Science.gov (United States)

    Ekberg, Kira; Wielandt, Alex G.; Buch-Pedersen, Morten J.; Palmgren, Michael G.

    2013-01-01

    The minimal proton pumping machinery of the Arabidopsis thaliana P-type plasma membrane H+-ATPase isoform 2 (AHA2) consists of an aspartate residue serving as key proton donor/acceptor (Asp-684) and an arginine residue controlling the pKa of the aspartate. However, other important aspects of the proton transport mechanism such as gating, and the ability to occlude protons, are still unclear. An asparagine residue (Asn-106) in transmembrane segment 2 of AHA2 is conserved in all P-type plasma membrane H+-ATPases. In the crystal structure of the plant plasma membrane H+-ATPase, this residue is located in the putative ligand entrance pathway, in close proximity to the central proton donor/acceptor Asp-684. Substitution of Asn-106 resulted in mutant enzymes with significantly reduced ability to transport protons against a membrane potential. Sensitivity toward orthovanadate was increased when Asn-106 was substituted with an aspartate residue, but decreased in mutants with alanine, lysine, glutamine, or threonine replacement of Asn-106. The apparent proton affinity was decreased for all mutants, most likely due to a perturbation of the local environment of Asp-684. Altogether, our results demonstrate that Asn-106 is important for closure of the proton entrance pathway prior to proton translocation across the membrane. PMID:23420846

  11. WITHDRAWN: Proton pump inhibitor treatment for acute peptic ulcer bleeding.

    Science.gov (United States)

    Leontiadis, Grigorios I; Sharma, Virender Kumar; Howden, Colin W

    2010-05-12

    Randomised controlled trials (RCTs) evaluating the clinical effect of proton pump inhibitors (PPIs) in peptic ulcer (PU) bleeding yield conflicting results. To evaluate the efficacy of PPIs in acute bleeding from PU using evidence from RCTs. We searched CENTRAL, The Cochrane Library (Issue 4, 2004), MEDLINE (1966 to November 2004), EMBASE (1980 to November 2004), proceedings of major meetings to November 2004, and reference lists of articles. We contacted pharmaceutical companies and experts in the field. RCTs of PPI treatment (oral or intravenous) compared with placebo or H(2)-receptor antagonist (H(2)RA) in acute bleeding from PU. Two reviewers extracted data independently, assessed study validity, summarised studies and undertook meta-analysis. The influence of study characteristics on the outcomes was examined by subgroup analyses and meta-regression. Twenty-four RCTs comprising 4373 participants in total were included. Statistical heterogeneity was found among trials for rebleeding (P = 0.04), but not for all-cause mortality (P = 0.24) or surgery (P = 0.45). There was no significant difference in all-cause mortality rates between PPI and control treatment; pooled rates were 3.9% on PPI versus 3.8% on control (odds ratio (OR) 1.01; 95% CI 0.74 to 1.40). PPIs significantly reduced rebleeding compared to control; pooled rates were 10.6% with PPI versus 17.3% with control treatment (OR 0.49; 95% CI 0.37 to 0.65). PPI treatment significantly reduced surgery compared with control; pooled rates were 6.1% on PPI versus 9.3% on control (OR 0.61; 95% CI 0.48 to 0.78). There was no evidence to suggest that results on mortality and rebleeding were dependent on study quality, route of PPI administration, type of control treatment or application of initial endoscopic haemostatic treatment. PPIs significantly reduced surgery compared with placebo but not when compared with H(2)RA. There was no evidence to suggest that study quality, route of PPI administration or application

  12. Drug Repositioning of Proton Pump Inhibitors for Enhanced Efficacy and Safety of Cancer Chemotherapy

    Directory of Open Access Journals (Sweden)

    Kenji Ikemura

    2017-12-01

    Full Text Available Proton pump inhibitors (PPIs, H+/K+-ATPase inhibitors, are the most commonly prescribed drugs for the treatment of gastroesophageal reflux and peptic ulcer diseases; they are highly safe and tolerable. Since PPIs are frequently used in cancer patients, studies investigating interactions between PPIs and anticancer agents are of particular importance to achieving effective and safe cancer chemotherapy. Several studies have revealed that PPIs inhibit not only the H+/K+-ATPase in gastric parietal cells, but also the vacuolar H+-ATPase (V-ATPase overexpressed in tumor cells, as well as the renal basolateral organic cation transporter 2 (OCT2 associated with pharmacokinetics and/or renal accumulation of various drugs, including anticancer agents. In this mini-review, we summarize the current knowledge regarding the impact of PPIs on the efficacy and safety of cancer chemotherapeutics via inhibition of targets other than the H+/K+-ATPase. Co-administration of clinical doses of PPIs protected kidney function in patients receiving cisplatin and fluorouracil, presumably by decreasing accumulation of cisplatin in the kidney via OCT2 inhibition. In addition, co-administration or pretreatment with PPIs could inhibit H+ transport via the V-ATPase in tumor cells, resulting in lower extracellular acidification and intracellular acidic vesicles to enhance the sensitivity of the tumor cells to the anticancer agents. In the present mini-review, we suggest that PPIs enhance the efficacy and safety of anticancer agents via off-target inhibition (e.g., of OCT2 and V-ATPase, rather than on-target inhibition of the H+/K+-ATPase. The present findings should provide important information to establish novel supportive therapy with PPIs during cancer chemotherapy.

  13. Molecular mechanisms controlling proton pumping by bacteriorhodopsin. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crouch, Rosalie K.; Ebrey, Thomas G.

    2000-02-10

    Bacteriorhodopsin (bR) is the simplest biological system for the transduction of light energy. Light energy is directly converted to transmembrane proton gradient by a single, small membrane protein. The extraordinary stability of bR makes it an outstanding subject for bioenergetic studies. This project has focused on the role of interactions between key residues of the pigment involved in light-induced proton transfer. Methods to estimate the strength of these interactions and their correlation with the rate and efficiency of proton transfer have been developed. The concept of the coupling of the protonation states of key groups has been applied to individual steps of the proton transfer with the ultimate goal of understanding on the molecular level the driving forces for proton transport and the pathway of the transported proton in bT. The mechanism of light-induced proton release, uptake and the mechanism of recovery of initial state of bT has been examined. The experiments were performed with genetically engineered, site-specific mutants of bR. This has enabled us to characterize the role of individual amino acid residues in bR. Time resolved and low temperature absorption spectroscopy and light-induced photocurrent measurements were used in order to study the photochemical cycle and proton transfer in mutant pigments. Chemical modification and crosslinking of both the specific amino acids to the chromophore or to other amino acids were used to elucidate the role of light-induced conformational changes in the photocycle and the structure of the protein in the ground state. The results of this project provided new knowledge on the architecture of the proton transfer pathways inside the protein, on the mechanism of proton release in bR, and on the role of specific amino acid residues in the structure and function of bR.

  14. Functional dissection of the proton pumping modules of mitochondrial complex I.

    Directory of Open Access Journals (Sweden)

    Stefan Dröse

    2011-08-01

    Full Text Available Mitochondrial complex I, the largest and most complicated proton pump of the respiratory chain, links the electron transfer from NADH to ubiquinone to the pumping of four protons from the matrix into the intermembrane space. In humans, defects in complex I are involved in a wide range of degenerative disorders. Recent progress in the X-ray structural analysis of prokaryotic and eukaryotic complex I confirmed that the redox reactions are confined entirely to the hydrophilic peripheral arm of the L-shaped molecule and take place at a remarkable distance from the membrane domain. While this clearly implies that the proton pumping within the membrane arm of complex I is driven indirectly via long-range conformational coupling, the molecular mechanism and the number, identity, and localization of the pump-sites remains unclear. Here, we report that upon deletion of the gene for a small accessory subunit of the Yarrowia complex I, a stable subcomplex (nb8mΔ is formed that lacks the distal part of the membrane domain as revealed by single particle analysis. The analysis of the subunit composition of holo and subcomplex by three complementary proteomic approaches revealed that two (ND4 and ND5 of the three subunits with homology to bacterial Mrp-type Na(+/H(+ antiporters that have been discussed as prime candidates for harbouring the proton pumps were missing in nb8mΔ. Nevertheless, nb8mΔ still pumps protons at half the stoichiometry of the complete enzyme. Our results provide evidence that the membrane arm of complex I harbours two functionally distinct pump modules that are connected in series by the long helical transmission element recently identified by X-ray structural analysis.

  15. Proton-pump inhibitors are associated with increased cardiovascular risk independent of clopidogrel use: a nationwide cohort study

    DEFF Research Database (Denmark)

    Charlot, Mette; Ahlehoff, Ole; Norgaard, Mette Lykke

    2010-01-01

    Controversy remains on whether the dual use of clopidogrel and proton-pump inhibitors (PPIs) affects clinical efficacy of clopidogrel.......Controversy remains on whether the dual use of clopidogrel and proton-pump inhibitors (PPIs) affects clinical efficacy of clopidogrel....

  16. ATP-driven calcium transport in membrane vesicles of Streptococcus sanguis. [Streptococcus sanguis; Streptococcus faecalis; Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Houng, H.; Lynn, A.R.; Rosen, B.P.

    1986-11-01

    Calcium transport was investigated in membrane vesicles prepared from the oral bacterium Streptococcus sanguis. Procedures were devised for the preparation of membrane vesicles capable of accumulation /sup 45/Ca/sup 2 +/. Uptake was ATP dependent and did not require a proton motive force. Calcium transport in these vesicles was compared with /sup 45/Ca/sup 2 +/ accumulation in membrane vesicles from Streptococcus faecalis and Escherichia coli. The data support the existence of an ATP-driven calcium pump in S. sanguis similar to that in S. faecalis. This pump, which catalyzes uptake into membrane vesicles, would be responsible for extrusion of calcium from intact cells.

  17. Should Helicobacter pylori be eradicated before starting long-term proton pump inhibitors?

    NARCIS (Netherlands)

    Rauws, E. A.

    1997-01-01

    Symptomatic gastro-oesophageal reflux disease is a common disorder characterized by pathological exposure of the distal oesophagus to acid. The management requires the control of symptoms, prevention of relapse and complications. Proton pump inhibitors are without doubt the most effective agents in

  18. The influence of proton pump inhibitors and other commonly used medication on the gut microbiota

    NARCIS (Netherlands)

    Imhann, Floris; Vich Vila, Arnau; Bonder, Marc Jan; Lopez Manosalva, Ailine G; Koonen, Debby P Y; Fu, Jingyuan; Wijmenga, Cisca; Zhernakova, Alexandra; Weersma, Rinse K

    2017-01-01

    Proton pump inhibitors (PPIs), used to treat gastro-esophageal reflux and prevent gastric ulcers, are among the most widely used drugs in the world. The use of PPIs is associated with an increased risk of enteric infections. Since the gut microbiota can, depending on composition, increase or

  19. Clinical effects of proton pump inhibitors: Focus on pharmacogenetics, kinetics and dynamics

    NARCIS (Netherlands)

    N.G.M. Hunfeld (Nicole)

    2010-01-01

    textabstractThis thesis describes the clinical effects of proton pump inhibitors, with focus on pharmacogenetics, kinetics and dynamics. The aims were to investigate the occurence of Rebound Acid Hypersecretion and to investigate the speed of onset, the duration of effect and the difference in

  20. Limited ability of the proton-pump inhibitor test to identify patients with gastroesophageal reflux disease

    DEFF Research Database (Denmark)

    Bytzer, Peter; Jones, Roger; Vakil, Nimish

    2012-01-01

    The efficacy of proton-pump inhibitor (PPI) therapy often is assessed to determine whether patients' symptoms are acid-related and if patients have gastroesophageal reflux disease (GERD), although the accuracy of this approach is questionable. We evaluated the diagnostic performance of the PPI te...

  1. Development of a tritium monitor combined with an electrochemical tritium pump using a proton conducting oxide

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, M. [National Institute for Fusion Science, Toki, Gifu (Japan); Sugiyama, T. [Nagoya University, Fro-cho, Chikusa-ku, Nagoya (Japan)

    2015-03-15

    The detection of low level tritium is one of the key issues for tritium management in tritium handling facilities. Such a detection can be performed by tritium monitors based on proton conducting oxide technique. We tested a tritium monitoring system composed of a commercial proportional counter combined with an electrochemical hydrogen pump equipped with CaZr{sub 0.9}In{sub 0.1}O{sub 3-α} as proton conducting oxide. The hydrogen pump operated at 973 K under electrolysis conditions using tritiated water vapor (HTO). The proton conducting oxide extracts tritium molecules (HT) from HTO and tritium concentration is measured by the proportional counter. The advantage of the proposed tritium monitoring system is that it is able to convert HTO into molecular hydrogen.

  2. Therapeutic substitution post-patent expiry: the cases of ACE inhibitors and proton pump inhibitors.

    Science.gov (United States)

    Vandoros, Sotiris

    2014-05-01

    This paper examines whether there is a switch in total (originator and generic) consumption after generic entry from molecules that face generic competition towards other molecules of the same class, which are still in-patent. Data from six European countries for the time period 1991 to 2006 are used to study the cases of angiotensin-converting enzyme inhibitors and proton pump inhibitors. Empirical evidence shows that patent expiry of captopril and enalapril led to a switch in total (off-patent originator and generic) consumption towards other in-patent angiotensin-converting enzyme inhibitors, whereas patent expiry of omeprazole led to a switch in consumption towards other proton pump inhibitors. This phenomenon makes generic policies ineffective and results in an increase in pharmaceutical expenditure due to the absence of generic alternatives in the market of in-patent molecules. Copyright © 2013 John Wiley & Sons, Ltd.

  3. A Review of the Novel Application and Potential Adverse Effects of Proton Pump Inhibitors

    OpenAIRE

    Yu, Li-Yuan; Sun, Lu-Ning; ZHANG Xue-hui; Li, Yue-Qi; Yu, Lei; Yuan, Zi-Qing-Yun; Meng, Ling; Zhang, Hong-Wen; Wang, Yong-Qing

    2017-01-01

    Proton pump inhibitors (PPIs) are known as a class of pharmaceutical agents that target H+/K+-ATPase, which is located in gastric parietal cells. PPIs are widely used in the treatment of gastric acid-related diseases including peptic ulcer disease, erosive esophagitis and gastroesophageal reflux disease, and so on. These drugs present an excellent safety profile and have become one of the most commonly prescribed drugs in primary and specialty care. Except for gastric acid-related diseases, P...

  4. Gastroesophageal reflux symptoms not responding to proton pump inhibitor: GERD, NERD, NARD, esophageal hypersensitivity or dyspepsia?

    OpenAIRE

    Bashashati, Mohammad; Hejazi, Reza A; Andrews, Christopher N; Storr, Martin A

    2014-01-01

    Gastroesophageal reflux (GER) is a common gastrointestinal process that can generate symptoms of heartburn and chest pain. Proton pump inhibitors (PPIs) are the gold standard for the treatment of GER; however, a substantial group of GER patients fail to respond to PPIs. In the past, it was believed that acid reflux into the esophagus causes all, or at least the majority, of symptoms attributed to GER, with both erosive esophagitis and nonerosive outcomes. However, with modern testing techniqu...

  5. High risk of drug-induced microscopic colitis with concomitant use of NSAIDs and proton pump inhibitors

    NARCIS (Netherlands)

    Verhaegh, B P M; de Vries, F; Masclee, A A M; Keshavarzian, A; de Boer, A; Souverein, P C; Pierik, M J; Jonkers, D M A E

    2016-01-01

    BACKGROUND: Microscopic colitis (MC) is a chronic bowel disorder characterised by watery diarrhoea. Nonsteroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), selective serotonin reuptake inhibitors (SSRIs) and statins have been associated with MC. However, underlying mechanisms

  6. Optical silencing of C. elegans cells with arch proton pump.

    Directory of Open Access Journals (Sweden)

    Ayako Okazaki

    Full Text Available BACKGROUND: Optogenetic techniques using light-driven ion channels or ion pumps for controlling excitable cells have greatly facilitated the investigation of nervous systems in vivo. A model organism, C. elegans, with its small transparent body and well-characterized neural circuits, is especially suitable for optogenetic analyses. METHODOLOGY/PRINCIPAL FINDINGS: We describe the application of archaerhodopsin-3 (Arch, a recently reported optical neuronal silencer, to C. elegans. Arch::GFP expressed either in all neurons or body wall muscles of the entire body by means of transgenes were localized, at least partially, to the cell membrane without adverse effects, and caused locomotory paralysis of worms when illuminated by green light (550 nm. Pan-neuronal expression of Arch endowed worms with quick and sustained responsiveness to such light. Worms reliably responded to repeated periods of illumination and non-illumination, and remained paralyzed under continuous illumination for 30 seconds. Worms expressing Arch in different subsets of motor neurons exhibited distinct defects in the locomotory behavior under green light: selective silencing of A-type motor neurons affected backward movement while silencing of B-type motor neurons affected forward movement more severely. Our experiments using a heat-shock-mediated induction system also indicate that Arch becomes fully functional only 12 hours after induction and remains functional for more than 24 hour. CONCLUSIONS/SGNIFICANCE: Arch can be used for silencing neurons and muscles, and may be a useful alternative to currently widely used halorhodopsin (NpHR in optogenetic studies of C. elegans.

  7. Surgery and proton pump inhibitors for treatment of vocal process granulomas.

    Science.gov (United States)

    Hong-Gang, Duan; He-Juan, Jin; Chun-Quan, Zheng; Guo-Kang, Fan

    2013-11-01

    The aim of this study was to analyze the outcomes of vocal process granulomas treated with surgery and proton pump inhibitors and to specify related factors of recurrence. The medical records of patients with diagnosis of vocal process granuloma between 2000 and 2012 were reviewed. All patients were treated with surgery and proton pump inhibitors for at least 1 month. Forty-one patients were reviewed; mean follow-up time was 45 months. There was no recurrence among the patients who had a recent history of intubation. The recurrence rates of contact granuloma was 38.7 %, and significantly related to the frequency of surgery (P = 0.042), but was not significantly associated with the history of acid reflux (P = 0.676) and vocal abuse (P = 0.447), lesion size (P = 0.203) or surgical techniques (P = 0.331). Surgery combined with proton pump inhibitors was partially effective for the vocal process granulomas, especially with intubated patients. However, repeat surgery for recurrent contact granuloma should be preceded with caution due to high recurrence rates.

  8. The effects of long-term therapy with proton pump inhibitors on meal stimulated gastrin.

    Science.gov (United States)

    Helgadóttir, Hólmfridur; Metz, David C; Yang, Yu-Xiao; Rhim, Andrew D; Björnsson, Einar S

    2014-02-01

    Dyspepsia develops in healthy volunteers after withdrawal of proton-pump inhibitors. This phenomenon, attributed to rebound acid hypersecretion, is thought to be mediated by reflex hypergastrinemia. To measure fasting and postprandial gastrin in patients on long-term proton-pump inhibitor treatment and correlate gastrin levels with the duration of treatment and other potential predictors. In this cross sectional study patients, with erosive esophagitis, on long-term proton-pump inhibitor treatment and healthy controls underwent gastrin measurements at baseline and four times following a meal and Helicobacter pylori status was determined. A total of 100 patients and 50 controls were studied. Pre- and postprandial gastrin levels were higher in patients (pgastrin-curve and the treatment duration. Female patients had significantly higher gastrin levels than males pre- and postprandial, whereas such differences was not found in the control group. Female gender was the only independent predictor of s-gastrin levels (OR 2.50 compared to males, 95% CI: 1.08-5.76, p=0.032) in the patient group. Gastrin values were higher in patients compared to controls. There was no correlation between gastrin levels and treatment duration. Female patients had significantly higher gastrin values than males. Copyright © 2013 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  9. Proton pump inhibitors as anti vacuolar-ATPases drugs: a novel anticancer strategy

    Directory of Open Access Journals (Sweden)

    Fais Stefano

    2010-05-01

    Full Text Available Abstract The vacuolar ATPases are ATP-dependent proton pumps whose functions include the acidification of intracellular compartments and the extrusion of protons through the cell cytoplasmic membrane. These pumps play a pivotal role in the regulation of cell pH in normal cells and, to a much greater extent, in tumor cells. In fact, the glucose metabolism in hypoxic conditions by the neoplasms leads to an intercellular pH drift towards acidity. The acid microenvironment is modulated through the over-expression of H+ transporters that are also involved in tumor progression, invasiveness, distant spread and chemoresistance. Several strategies to block/downmodulate the efficiency of these transporters are currently being investigated. Among them, proton pump inhibitors have shown to successfully block the H+ transporters in vitro and in vivo, leading to apoptotic death. Furthermore, their action seems to synergize with conventional chemotherapy protocols, leading to chemosensitization and reversal of chemoresistance. Aim of this article is to critically revise the current knowledge of this cellular machinery and to summarize the therapeutic strategies developed to counter this mechanism.

  10. The safety of proton pump inhibitors in pregnancy: a multicentre prospective controlled study.

    Science.gov (United States)

    Diav-Citrin, O; Arnon, J; Shechtman, S; Schaefer, C; van Tonningen, M R; Clementi, M; De Santis, M; Robert-Gnansia, E; Valti, E; Malm, H; Ornoy, A

    2005-02-01

    Proton pump inhibitors are used to treat gastro-oesophageal reflux and peptic ulcers. Gastro-oesophageal reflux is a common condition in pregnancy. Human pregnancy experience with lansoprazole or pantoprazole is very limited. More data exist on the safety of omeprazole in pregnancy. To assess the safety of proton pump inhibitors in pregnancy. The rate of major anomalies was compared between pregnant women exposed to omeprazole, lanzoprazole, or pantoprazole and a control group counselled for non-teratogens. The study design is a multicentre (n = 8), prospective, controlled study of the European Network of Teratology Information Services. We followed up 295 pregnancies exposed to omeprazole [233 in the first trimester (T1)], 62 to lansoprazole (55 in T1) and 53 to pantoprazole (47 in T1), and compared pregnancy outcome to that of 868 European Network of Teratology Information Services controls. The rate of major congenital anomalies did not differ between the exposed and control groups [omeprazole nine of 249 (3.6%), lansoprazole two of 51 (3.9%) and pantoprazole one of 48 (2.1%) vs. controls 30 of 792 = 3.8%]. No differences were found when exposure was limited to the first trimester after exclusion of genetic, cytogenetic or infectious anomalies. This study suggests that proton pump inhibitors do not represent a major teratogenic risk in humans.

  11. Reaction of proton pump inhibitors with model peptides results in novel products.

    Science.gov (United States)

    Watson, Charles; Zhu, Lixin; Guan, Shenheng; Machen, Terry E; Forte, John G

    2013-01-01

    The proposed mechanism for proton pump inhibitors (PPIs) is that PPIs are activated at low pH to the sulfenamide form, which reacts with the sulfhydryl group of cysteine(s) at the active site of the proton pump, to produce reducible disulfide-bonded PPI-proton pump conjugates. However, this mechanism cannot explain the observations that some PPI-protein conjugates are irreducible. This study was designed to investigate the chemistry of the irreducible conjugates by mass spectrometry, using three PPIs and 17 cysteine-containing peptides. While some peptides favored the formation of reducible PPI-peptide adduct, the other peptides mainly produced irreducible adducts. Characterization of the irreducible adduct revealed that the irreducible bonding required the participation of both a sulfhydryl group and a nearby primary amino group. High resolution mass spectrometry suggested a molecular structure of the irreducible adduct. These results suggested a reaction mechanism in which the PPI pyridone form reacted with an amino group and a sulfhydryl group to form an irreducible adduct. The irreducible adduct becomes the dominant product over time because of the irreversible nature of the pyridone-mediated reaction. These findings may explain the irreducible inhibition of H/K-ATPase by PPIs and their relatively slow biological turnover in vivo. [Supplementary materials: available only at http://dx.doi.org/10.1254/jphs.13058FP].

  12. Proton Pump Inhibition Increases Rapid Eye Movement Sleep in the Rat

    Directory of Open Access Journals (Sweden)

    Munazah Fazal Qureshi

    2014-01-01

    Full Text Available Increased bodily CO2 concentration alters cellular pH as well as sleep. The proton pump, which plays an important role in the homeostatic regulation of cellular pH, therefore, may modulate sleep. We investigated the effects of the proton pump inhibitor “lansoprazole” on sleep-wakefulness. Male Wistar rats were surgically prepared for chronic polysomnographic recordings. Two different doses of lansoprazole (low: 1 mg/kg; high: 10 mg/kg were injected intraperitoneally in the same animal (n=7 and sleep-wakefulness was recorded for 6 hrs. The changes in sleep-wakefulness were compared statistically. Percent REM sleep amount in the vehicle and lansoprazole low dose groups was 9.26±1.03 and 9.09±0.54, respectively, which increased significantly in the lansoprazole high dose group by 31.75% (from vehicle and 34.21% (from low dose. Also, REM sleep episode numbers significantly increased in lansoprazole high dose group. Further, the sodium-hydrogen exchanger blocker “amiloride” (10 mg/kg; i.p. (n=5 did not alter sleep-wake architecture. Our results suggest that the proton pump plays an important role in REM sleep modulation and supports our view that REM sleep might act as a sentinel to help maintain normal CO2 level for unperturbed sleep.

  13. Functional and morphological changes of the mucous membrane of the stomach after long application of proton pump inhibitors

    Directory of Open Access Journals (Sweden)

    M. V. Markina

    2010-04-01

    Full Text Available Changes of mucous membrane of rats’ stomach after long term application of proton pump inhibition – Omeprazole. Increase of pepsin concentration, volume and рН in both fasting and basal gastric juice in comparison with the control was observed. It is established that the content of nitrates and nitrites in gastric juice and in the rats’ mixed saliva after the 12th day of introduction of proton pump inhibitors is 3:1.

  14. Voltage dependence of proton pumping by bacteriorhodopsin mutants with altered lifetime of the M intermediate.

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    Sven Geibel

    Full Text Available The light-driven proton pump bacteriorhodopsin (BR from Halobacterium salinarum is tightly regulated by the [H(+] gradient and transmembrane potential. BR exhibits optoelectric properties, since spectral changes during the photocycle are kinetically controlled by voltage, which predestines BR for optical storage or processing devices. BR mutants with prolonged lifetime of the blue-shifted M intermediate would be advantageous, but the optoelectric properties of such mutants are still elusive. Using expression in Xenopus oocytes and two-electrode voltage-clamping, we analyzed photocurrents of BR mutants with kinetically destabilized (F171C, F219L or stabilized (D96N, D96G M intermediate in response to green light (to probe H(+ pumping and blue laser flashes (to probe accumulation/decay of M. These mutants have divergent M lifetimes. As for BR-WT, this strictly correlates with the voltage dependence of H(+ pumping. BR-F171C and BR-F219L showed photocurrents similar to BR-WT. Yet, BR-F171C showed a weaker voltage dependence of proton pumping. For both mutants, blue laser flashes applied during and after green-light illumination showed reduced M accumulation and shorter M lifetime. In contrast, BR-D96G and BR-D96N exhibited small photocurrents, with nonlinear current-voltage curves, which increased strongly in the presence of azide. Blue laser flashes showed heavy M accumulation and prolonged M lifetime, which accounts for the strongly reduced H(+ pumping rate. Hyperpolarizing potentials augmented these effects. The combination of M-stabilizing and -destabilizing mutations in BR-D96G/F171C/F219L (BR-tri shows that disruption of the primary proton donor Asp-96 is fatal for BR as a proton pump. Mechanistically, M destabilizing mutations cannot compensate for the disruption of Asp-96. Accordingly, BR-tri and BR-D96G photocurrents were similar. However, BR-tri showed negative blue laser flash-induced currents even without actinic green light, indicating

  15. Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps

    Science.gov (United States)

    Vedovato, Natascia

    2014-01-01

    A single Na+/K+-ATPase pumps three Na+ outwards and two K+ inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na+ than K+ generates outward current across the cell membrane. Less well understood is the ability of Na+/K+ pumps to generate an inward current of protons. Originally noted in pumps deprived of external K+ and Na+ ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K+ and Na+ concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na+ release from phosphorylated Na+/K+ pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na+/K+ pumps that enables proton import is not required for completion of the 3 Na+/2 K+ transport cycle. However, the back-step occurs readily during Na+/K+ transport when external K+ ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na+-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na+ and K+ ions that passes through binding site II. The inferred occurrence of Na+/K+ exchange and H+ import during the same conformational cycle of a single molecule identifies the Na+/K+ pump as a hybrid transporter. Whether Na+/K+ pump–mediated proton inflow may have any physiological or pathophysiological significance remains to be clarified. PMID

  16. How cytochrome c oxidase can pump four protons per oxygen molecule at high electrochemical gradient.

    Science.gov (United States)

    Blomberg, Margareta R A; Siegbahn, Per E M

    2015-03-01

    Experiments have shown that the A-family cytochrome c oxidases pump four protons per oxygen molecule, also at a high electrochemical gradient. This has been considered a puzzle, since two of the reduction potentials involved, Cu(II) and Fe(III), were estimated from experiments to be too low to afford proton pumping at a high gradient. The present quantum mechanical study (using hybrid density functional theory) suggests a solution to this puzzle. First, the calculations show that the charge compensated Cu(II) potential for CuB is actually much higher than estimated from experiment, of the same order as the reduction potentials for the tyrosyl radical and the ferryl group, which are also involved in the catalytic cycle. The reason for the discrepancy between theory and experiment is the very large uncertainty in the experimental observations used to estimate the equilibrium potentials, mainly caused by the lack of methods for direct determination of reduced CuB. Second, the calculations show that a high energy metastable state, labeled EH, is involved during catalytic turnover. The EH state mixes the low reduction potential of Fe(III) in heme a3 with another, higher potential, here suggested to be that of the tyrosyl radical, resulting in enough exergonicity to allow proton pumping at a high gradient. In contrast, the corresponding metastable oxidized state, OH, is not significantly higher in energy than the resting state, O. Finally, to secure the involvement of the high energy EH state it is suggested that only one proton is taken up via the K-channel during catalytic turnover. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. MODULATION OF GROWTH AND PROTON PUMPING ATPase ACTIVITY OF PROBIOTIC Lactobacilli BY DIETARY CUCURBITS

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    Irfan Ahmad

    2013-12-01

    Full Text Available Gastrointestinal tract predominantly harbor probiotic Lactobacilli which exert beneficial effects on human health. Aqueous extracts from fruits of Lagenaria siceraria (Ls, Luffa cylindrica (Lc and Cucurbita maxima (Cm were prepared and lyophilized. Fruit extracts were investigated for their effects on Lactobacillus rhamnosus (L. rhamnosus, Lactobacillus plantarum (L. plantarum and Lactobacillus acidophilus (L. acidophilus. Extracts were found to enhance growth of Lactobacilli without any toxic effect (up to 1000µg/mL concentration. Minimum concentration of extracts at which growth of probiotic strains were found to be enhanced significantly were determined (103.67 µg/mL-118µg/mL and considered as effective concentration (EC or growth stimulatory concentration (GSC. Proton pumping ATPase activity of Lactobacilli were examined and found to be enhanced significantly (29.89- 61.96% in extracts treated probiotics (Lactobacilli as compared to the normal control. Inulin used as positive control and found to enhance the proton efflux activity (28.06-37.72% with respect to the control. These dietary cucurbits enhance metabolic activity of probiotic Lactobacilli by modulating their proton pumping ATPase mechanism. This study suggested that the consumption of cucurbit fruits might be a natural source of enhancing the activities of probiotic Lactobacilli in the gut.

  18. Enhancement of survival and electricity production in an engineered bacterium by light-driven proton pumping.

    Science.gov (United States)

    Johnson, Ethan T; Baron, Daniel B; Naranjo, Belén; Bond, Daniel R; Schmidt-Dannert, Claudia; Gralnick, Jeffrey A

    2010-07-01

    Microorganisms can use complex photosystems or light-dependent proton pumps to generate membrane potential and/or reduce electron carriers to support growth. The discovery that proteorhodopsin is a light-dependent proton pump that can be expressed readily in recombinant bacteria enables development of new strategies to probe microbial physiology and to engineer microbes with new light-driven properties. Here, we describe functional expression of proteorhodopsin and light-induced changes in membrane potential in the bacterium Shewanella oneidensis strain MR-1. We report that there were significant increases in electrical current generation during illumination of electrochemical chambers containing S. oneidensis expressing proteorhodopsin. We present evidence that an engineered strain is able to consume lactate at an increased rate when it is illuminated, which is consistent with the hypothesis that proteorhodopsin activity enhances lactate uptake by increasing the proton motive force. Our results demonstrate that there is coupling of a light-driven process to electricity generation in a nonphotosynthetic engineered bacterium. Expression of proteorhodopsin also preserved the viability of the bacterium under nutrient-limited conditions, providing evidence that fulfillment of basic energy needs of organisms may explain the widespread distribution of proteorhodopsin in marine environments.

  19. Potential regulatory phosphorylation sites in a Medicago truncatula plasma membrane proton pump implicated during early symbiotic signaling in roots.

    Science.gov (United States)

    Nguyen, Thao T; Volkening, Jeremy D; Rose, Christopher M; Venkateshwaran, Muthusubramanian; Westphall, Michael S; Coon, Joshua J; Ané, Jean-Michel; Sussman, Michael R

    2015-08-04

    In plants and fungi the plasma membrane proton pump generates a large proton-motive force that performs essential functions in many processes, including solute transport and the control of cell elongation. Previous studies in yeast and higher plants have indicated that phosphorylation of an auto-inhibitory domain is involved in regulating pump activity. In this report we examine the Medicago truncatula plasma membrane proton pump gene family, and in particular MtAHA5. Yeast complementation assays with phosphomimetic mutations at six candidate sites support a phosphoregulatory role for two residues, suggesting a molecular model to explain early Nod factor-induced changes in the plasma membrane proton-motive force of legume root cells. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  20. What you need to know when you prescribe a proton pump inhibitor.

    Science.gov (United States)

    Norman, A; Hawkey, C J

    2011-10-01

    Ever since they were launched, proton pump inhibitors (PPIs) have been regarded as profligate prescription interventions and have become a favourite target for pharmacy advisers. Now that they are cheap, with generic omeprazole 20 mg daily costing £1.88 per month (£24.51 per annum) in the UK, it is time to ask whether this status should be reviewed, whether there are areas where the message should be reversed and whether there are any circumstances in which the extra cost of branded PPIs or combined preparations is justified. Equally, with the recognition of an extended toxicity profile, is prescribing profligacy not an economic but a safety issue?

  1. Proton Pump Inhibitors in the Management of Tachypnoea following Panproctocolectomy: A Case of High Output Ileostomy

    Directory of Open Access Journals (Sweden)

    Neville Azzopardi

    2011-04-01

    Full Text Available High output ileostomies are important complications of stoma formation following bowel surgery. Adequate management of such stomas might prevent severe morbidity and mortality when this potentially fatal complication develops. In this case report, we describe a female patient with a recent ileostomy formation following panproctocolectomy for ulcerative colitis who presented with progressively increasing shortness of breath. The patient was found to have a hypochloraemic metabolic acidosis on arterial blood gases. She rapidly improved with adequate sodium and fluid replacement and with the use of a course of proton pump inhibitors. This case highlights the importance of recognising high output ileostomies early and important management issues in their regard.

  2. Negative chronotropic effect of proton pump inhibitors on frog-heart preparation.

    Science.gov (United States)

    Gautam, Chander Shekhar; Utreja, Amita; Goel, Divya; Sandhu, Gurpreet; Gogia, Nidhi

    2009-01-01

    Proton pump inhibitors (PPIs) have been known to cause bradycardia. We evaluated the effect of three PPIs, i.e. omeprazole, rabeprazole and pantoprazole on the heart rate of frog. The in situ frog heart preparation was set up. Heart rate and amplitude of contraction were studied following administration of different doses of the three PPIs. Statistical analysis was done by using Graphpad statistical software system. After 1 mg of omeprazole and rabeprazole, and 2 mg pantoprazole, the heart rate was similar as compared to baseline (p >0.05). After 2 mg of omeprazole and rabeprazole, and 4 mg pantoprazole, the reduction in heart rate was significant (p frog heart prepration.

  3. Proton Pump Inhibitor use in Hospitalized Patients: Is Overutilization Becoming a Problem?

    Directory of Open Access Journals (Sweden)

    Cheryl Durand

    2012-01-01

    Full Text Available Proton pump inhibitors (PPIs are among the most common classes of medications prescribed. Though they were previously thought of as safe, recent literature has shown risks associated with their use including increased risk for Clostridium difficile infection, pneumonia, and fractures. Due to these risks, it is important to determine if PPIs are being used appropriately. This review evaluates seven studies in hospitalized patients. Additionally, this review evaluates literature pertaining to recently discovered adverse reactions; all studies found PPIs are being overutilized. Findings highlight the importance of evaluating appropriate therapy with these agents and recommending discontinuation if a proper indication does not exist.

  4. Proton pump inhibitors in rheumatic diseases: clinical practice, drug interactions, bone fractures and risk of infections

    Directory of Open Access Journals (Sweden)

    E. Gremese

    2011-06-01

    Full Text Available Patients affected by acute coronary syndrome (ACS or by chronic inflammatory musculoskeletal and connective tissue diseases (i.e. systemic sclerosis, often need antiaggregant therapy (ASA or Clopidogrel. The concomitant use of proton pump inhibitors (PPIs is suggested to reduce the risk of haemorrhage. Clopidogrel is a prodrug activated by cytocrome P 450. PPIs too have a CYP P450 metabolism, and a drug interaction has been observed between PPIs and clopidogrel. 25% of nonresponsiveness to clopidogrel is due to this drug interaction (1. Some studies have demonstrated that the use of PPIs is associated with an increased risk of bone fractures and Clostridium difficile infection.

  5. Proton Pumping and Slippage Dynamics of a Eukaryotic P-Type ATPase Studied at the Single-Molecule Level

    DEFF Research Database (Denmark)

    Veshaguri, Salome

    In all eukaryotes the plasma membrane potential and secondary transport systems are energized by P-type ATPases whose regulation however remains poorly understood. Here we monitored at the single-molecule level the activity of the prototypic proton pumping P-type ATPase Arabidopsis thaliana isoform...... pumping rates remained constant. Titration of ATP down to ~1% of apparent Km for ATPase activity exclusively affected the distributions of the durations the pump spends in active and inactive states. The dramatic consequence of our findings is that ATP reduction decreased ATP/H+ stoichiometry of the pump...

  6. Structure of a prokaryotic virtual proton pump at 3.2 Å resolution

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yiling; Jayaram, Hariharan; Shane, Tania; Kolmakova-Partensky, Ludmila; Wu, Fang; Williams, Carole; Xiong, Yong; Miller, Christopher; (Yale); (Brandeis)

    2009-09-15

    To reach the mammalian gut, enteric bacteria must pass through the stomach. Many such organisms survive exposure to the harsh gastric environment (pH 1.5-4) by mounting extreme acid-resistance responses, one of which, the arginine-dependent system of Escherichia coli, has been studied at levels of cellular physiology, molecular genetics and protein biochemistry. This multiprotein system keeps the cytoplasm above pH 5 during acid challenge by continually pumping protons out of the cell using the free energy of arginine decarboxylation. At the heart of the process is a 'virtual proton pump' in the inner membrane, called AdiC, that imports L-arginine from the gastric juice and exports its decarboxylation product agmatine. AdiC belongs to the APC superfamily of membrane proteins, which transports amino acids, polyamines and organic cations in a multitude of biological roles, including delivery of arginine for nitric oxide synthesis, facilitation of insulin release from pancreatic {beta}-cells, and, when inappropriately overexpressed, provisioning of certain fast-growing neoplastic cells with amino acids. High-resolution structures and detailed transport mechanisms of APC transporters are currently unknown. Here we describe a crystal structure of AdiC at 3.2 {angstrom} resolution. The protein is captured in an outward-open, substrate-free conformation with transmembrane architecture remarkably similar to that seen in four other families of apparently unrelated transport proteins.

  7. Structure of a Prokaryotic Virtual Proton Pump at 3.2 Astroms Resolution

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Y.; Jayaram, H; Shane, T; Partensky, L; Wu, F; williams, C; Xiong, Y; Miller, C

    2009-01-01

    To reach the mammalian gut, enteric bacteria must pass through the stomach. Many such organisms survive exposure to the harsh gastric environment (pH 1.5-4) by mounting extreme acid-resistance responses, one of which, the arginine-dependent system of Escherichia coli, has been studied at levels of cellular physiology, molecular genetics and protein biochemistry. This multiprotein system keeps the cytoplasm above pH 5 during acid challenge by continually pumping protons out of the cell using the free energy of arginine decarboxylation. At the heart of the process is a 'virtual proton pump' in the inner membrane, called AdiC, that imports L-arginine from the gastric juice and exports its decarboxylation product agmatine. AdiC belongs to the APC superfamily of membrane proteins, which transports amino acids, polyamines and organic cations in a multitude of biological roles, including delivery of arginine for nitric oxide synthesis, facilitation of insulin release from pancreatic beta-cells, and, when inappropriately overexpressed, provisioning of certain fast-growing neoplastic cells with amino acids. High-resolution structures and detailed transport mechanisms of APC transporters are currently unknown. Here we describe a crystal structure of AdiC at 3.2 A resolution. The protein is captured in an outward-open, substrate-free conformation with transmembrane architecture remarkably similar to that seen in four other families of apparently unrelated transport proteins.

  8. Interaction between clopidogrel and proton-pump inhibitors and management strategies in patients with cardiovascular diseases

    Directory of Open Access Journals (Sweden)

    Paul A Gurbel

    2010-11-01

    Full Text Available Paul A Gurbel1, Udaya S Tantry1, Dean J Kereiakes21Sinai Center for Thrombosis Research, Sinai Hospital of Baltimore, Baltimore, MD, USA; 2The Christ Hospital Heart and Vascular Center/The Lindner Research Center at The Christ Hospital, Cincinnati, OH, USAAbstract: Dual antiplatelet therapy (DAPT with clopidogrel and aspirin has been successful in reducing ischemic events in a wide range of patients with cardiovascular diseases. However, the anti-ischemic effects of DAPT may also be associated with gastrointestinal (GI complications including ulceration and bleeding particularly in ‘high risk’ and elderly patients. Current guidelines recommend the use of proton-pump inhibitors (PPIs to reduce the risk of GI bleeding in patients treated with DAPT. However, pharmacodynamic studies suggest an effect of PPIs on clopidogrel metabolism with a resultant reduction in platelet inhibitory effects. Similarly, several observational studies have demonstrated reduced clopidogrel benefit in patients who coadministered PPIs. Although recent US Food and Drug Administration and European Medicines Agency statements discourage PPI (particularly omeprazole and clopidogrel coadministration, the 2009 AHA/ACC/SCAI PCI guidelines do not support a change in current practice in the absence of adequately powered prospective randomized clinical trial data. The data regarding pharmacologic and clinical interactions between PPI and clopidogrel therapies are herein examined and treatment strategies are provided.Keywords: cardiovascular disease, gastrointestinal, proton-pump inhibitor, antiplatelet therapy

  9. BENEFITS VERSUS RISKS OF PROTON PUMP INHIBITORS: ARE WE OPENING THE CAN OF WORMS

    Directory of Open Access Journals (Sweden)

    Naser Ashraf Tadvi

    2016-01-01

    Full Text Available Proton pump inhibitors (PPIs are one of the most commonly used drugs worldwide They are indicated for treatment of Gastro-esophageal Reflux Disease (GERD, acid peptic disorders, stress ulcers and prophylaxis of NSAID induced ulcers.[1] PPIs are more efficacious than other drugs like histamine -2 receptor blockers for the treatment of these disorders.[1] Though PPIs are highly potent and effective acid suppressors they are often misused and prescribed irrationally. The incidence of irrational use of PPIs varies from 40-70 % in different studies. [2] In one of our previous studies 58 % of PPIs prescriptions were irrational. [2] These findings become much more significant in the light of recent findings which suggest correlation of long term use of PPIs to myocardial infarction and kidney injury. [3,4] The PPIs may be deemed safe for short term use but chronic use carries risk of hip fractures, infection with clostridium difficle, community acquired pneumonia.[2] PPIs exposure in elderly population was also found to be associated with hyperparathyroidism in one recently conducted study.[5] The ongoing long term studies for assessing the safety and association of PPIs with various serious outcomes may open up a new can of worms. Keeping in mind the benefits as well as risks of proton pump inhibitors, clinicians should judiciously use these drugs in practice. The patients should also be educated regarding the adverse outcomes of PPIs on long term therapy as these drugs are easily available without prescription.

  10. The prophylactic use of a proton pump inhibitor before food and alcohol.

    LENUS (Irish Health Repository)

    O'Leary, C

    2012-02-03

    BACKGROUND: Patients report that the prophylactic consumption of a proton pump inhibitor minimizes gastrointestinal symptoms expected to be provoked by late-night food and alcohol consumption. The efficacy of this practice has not been studied formally. AIM: To perform a randomized, double-blind, placebo-controlled trial of a single dose of lansoprazole (30 mg) taken prior to a large meal and alcohol consumption. METHODS: Study subjects were recruited randomly from local primary care and hospital physicians. Each participant (n = 56; 37 male, 19 female; mean age, 38 years) completed questionnaires before and after the meal. Approximately 90 min prior to the provocative meal, participants were witnessed taking either placebo or 30 mg lansoprazole. Bar tokens were dispensed to permit the accurate quantification of alcohol consumption (mean, 15 units). RESULTS: Forty per cent of subjects reported significant reflux symptoms. For the entire group, there was no significant difference between lansoprazole and placebo. Post-prandial reflux was more frequent in those consuming > 15 units of alcohol (13\\/26, 50%) compared with those consuming < 15 units (7\\/30, 24%; P < 0.05). In the group who consumed > 15 units of alcohol, lansoprazole was associated with a lower rate of heartburn (5\\/15, 33%) compared with placebo (8\\/11, 73%; P < 0.05). CONCLUSION: A single dose of a proton pump inhibitor prior to indulgence was only associated with reduced heartburn in those consuming > 15 units of alcohol.

  11. Dietary Inulin Fibers Prevent Proton-Pump Inhibitor (PPI)-Induced Hypocalcemia in Mice

    Science.gov (United States)

    Hess, Mark W.; de Baaij, Jeroen H. F.; Gommers, Lisanne M. M.; Hoenderop, Joost G. J.; Bindels, René J. M.

    2015-01-01

    Background Proton-pump inhibitor-induced hypomagnesemia (PPIH) is the most recognized side effect of proton-pump inhibitors (PPIs). Additionally, PPIH is associated with hypocalcemia and hypokalemia. It is hypothesized that PPIs reduce epithelial proton secretion and thereby increase the pH in the colon, which may explain the reduced absorption of and Mg2+ and Ca2+. Fermentation of dietary oligofructose-enriched inulin fibers by the microflora leads to acidification of the intestinal lumen and by this enhances mineral uptake. This study aimed, therefore, to improve mineral absorption by application of dietary inulin to counteract PPIH. Methods Here, C57BL/J6 mice were supplemented with omeprazole and/or inulin. Subsequently, Mg2+ and Ca2+ homeostasis was assessed by means of serum, urine and fecal electrolyte measurements. Moreover, the mRNA levels of magnesiotropic and calciotropic genes were examined in the large intestine and kidney by real-time PCR. Results Treatment with omeprazole significantly reduced serum Mg2+ and Ca2+ levels. However, concomitant addition of dietary inulin fibers normalized serum Ca2+ but not serum Mg2+ concentrations. Inulin abolished enhanced expression of Trpv6 and S100g in the colon by omeprazole. Additionally, intestinal and renal mRNA levels of the Trpm6 gene were reduced after inulin intake. Conclusions This study suggests that dietary inulin counteracts reduced intestinal Ca2+ absorption upon PPI treatment. In contrast, inulin did not increase intestinal absorption of Mg2+ sufficiently to recover serum Mg2+. The clinical potential of dietary inulin treatment should be the subject of future studies. PMID:26397986

  12. Dietary Inulin Fibers Prevent Proton-Pump Inhibitor (PPI-Induced Hypocalcemia in Mice.

    Directory of Open Access Journals (Sweden)

    Mark W Hess

    Full Text Available Proton-pump inhibitor-induced hypomagnesemia (PPIH is the most recognized side effect of proton-pump inhibitors (PPIs. Additionally, PPIH is associated with hypocalcemia and hypokalemia. It is hypothesized that PPIs reduce epithelial proton secretion and thereby increase the pH in the colon, which may explain the reduced absorption of and Mg2+ and Ca2+. Fermentation of dietary oligofructose-enriched inulin fibers by the microflora leads to acidification of the intestinal lumen and by this enhances mineral uptake. This study aimed, therefore, to improve mineral absorption by application of dietary inulin to counteract PPIH.Here, C57BL/J6 mice were supplemented with omeprazole and/or inulin. Subsequently, Mg2+ and Ca2+ homeostasis was assessed by means of serum, urine and fecal electrolyte measurements. Moreover, the mRNA levels of magnesiotropic and calciotropic genes were examined in the large intestine and kidney by real-time PCR.Treatment with omeprazole significantly reduced serum Mg2+ and Ca2+ levels. However, concomitant addition of dietary inulin fibers normalized serum Ca2+ but not serum Mg2+ concentrations. Inulin abolished enhanced expression of Trpv6 and S100g in the colon by omeprazole. Additionally, intestinal and renal mRNA levels of the Trpm6 gene were reduced after inulin intake.This study suggests that dietary inulin counteracts reduced intestinal Ca2+ absorption upon PPI treatment. In contrast, inulin did not increase intestinal absorption of Mg2+ sufficiently to recover serum Mg2+. The clinical potential of dietary inulin treatment should be the subject of future studies.

  13. Dietary Inulin Fibers Prevent Proton-Pump Inhibitor (PPI)-Induced Hypocalcemia in Mice.

    Science.gov (United States)

    Hess, Mark W; de Baaij, Jeroen H F; Gommers, Lisanne M M; Hoenderop, Joost G J; Bindels, René J M

    2015-01-01

    Proton-pump inhibitor-induced hypomagnesemia (PPIH) is the most recognized side effect of proton-pump inhibitors (PPIs). Additionally, PPIH is associated with hypocalcemia and hypokalemia. It is hypothesized that PPIs reduce epithelial proton secretion and thereby increase the pH in the colon, which may explain the reduced absorption of and Mg2+ and Ca2+. Fermentation of dietary oligofructose-enriched inulin fibers by the microflora leads to acidification of the intestinal lumen and by this enhances mineral uptake. This study aimed, therefore, to improve mineral absorption by application of dietary inulin to counteract PPIH. Here, C57BL/J6 mice were supplemented with omeprazole and/or inulin. Subsequently, Mg2+ and Ca2+ homeostasis was assessed by means of serum, urine and fecal electrolyte measurements. Moreover, the mRNA levels of magnesiotropic and calciotropic genes were examined in the large intestine and kidney by real-time PCR. Treatment with omeprazole significantly reduced serum Mg2+ and Ca2+ levels. However, concomitant addition of dietary inulin fibers normalized serum Ca2+ but not serum Mg2+ concentrations. Inulin abolished enhanced expression of Trpv6 and S100g in the colon by omeprazole. Additionally, intestinal and renal mRNA levels of the Trpm6 gene were reduced after inulin intake. This study suggests that dietary inulin counteracts reduced intestinal Ca2+ absorption upon PPI treatment. In contrast, inulin did not increase intestinal absorption of Mg2+ sufficiently to recover serum Mg2+. The clinical potential of dietary inulin treatment should be the subject of future studies.

  14. Partial symptom-response to proton pump inhibitors in patients with non-erosive reflux disease or reflux oesophagitis - a post hoc analysis of 5796 patients

    DEFF Research Database (Denmark)

    Bytzer, P; van Zanten, S Veldhuyzen; Mattsson, H

    2012-01-01

    Although most patients with gastro-oesophageal reflux disease (GERD) benefit from proton pump inhibitor (PPI) therapy, some experience only partial symptom relief.......Although most patients with gastro-oesophageal reflux disease (GERD) benefit from proton pump inhibitor (PPI) therapy, some experience only partial symptom relief....

  15. [In vitro susceptibility of Trichomonas vaginalis to metronidazole, ornidazole and proton pump inhibitors pantoprazole and esomeprazole].

    Science.gov (United States)

    Aksoy Gökmen, Ayşegül; Girginkardeşler, Nogay; Kilimcioğlu, Ali Ahmet; Şirin, Mümtaz Cem; Özbilgin, Ahmet

    2016-01-01

    The current treatment of trichomoniasis is based on the use of 5-nitroimidazole derivatives. Although metronidazole is reliable, inexpensive and highly effective against anaerobic microorganisms and protozoa, the development of metronidazole-resistant T.vaginalis strains pose to an increasing problem. Nitroimidazoles are compounds having azomycin (2-nitroimidazole) chemical structure and are obtained from Streptomyces strains. Benzimidazole, which is found in the structure of proton pump inhibitors, is also present in the other components that have antiprotozoal activity. In this study, the in vitro susceptibility of T.vaginalis against metronidazole, ornidazole, and the proton pump inhibitors which are tested recently as antiprotozoal agents; pantoprazole and esomeprazole was investigated. For this purpose a clinical T.vaginalis strain which was formerly isolated and stored after cryopreservation process in our laboratory was used. Minimum inhibitory concentration (MIC) and minimum lethal concentration (MLC) values of those agents against to this strain were determined in vitro by dilution method in 24-well cell culture plates. Trypticase yeast extract maltose medium, horse serum and antibiotic (penicillin + streptomycin) were distributed to each well of cell culture plates and after metronidazole, ornidazole, pantoprazole and esomeprazole solutions were added to two wells for each as 800, 400, 200, 100, 50 and 25 µg/ml, followed by the addition of 1 ml 5x10(3) T.vaginalis trophozoites into each well. Plates were incubated at 37°C, and viability and motility of the trophozoites were evaluated under light microscope at 24, 48 and 72 hours after incubation. MIC and MLC values of metronidazole/ornidazole in the 72(th) hour were found as 50 µg/ml and 100 µg/ml, respectively. MIC and MLC values for pantoprazole in the 72th hour were 200 µg/ml and 400 µg/ml, while the values for esomeprazole were 400 µg/ml ve 800 µg/ml, respectively. As a result, T

  16. FTIR spectroscopy of a light-driven compatible sodium ion-proton pumping rhodopsin at 77 K.

    Science.gov (United States)

    Ono, Hikaru; Inoue, Keiichi; Abe-Yoshizumi, Rei; Kandori, Hideki

    2014-05-08

    Krokinobacter eikastus rhodopsin 2 (KR2) is a light-driven sodium ion pump that was discovered in marine bacteria. Although KR2 is able to pump lithium ions similarly, it is converted into a proton pump in potassium chloride or salts of larger cations. In this paper, we applied light-induced difference Fourier-transform infrared (FTIR) spectroscopy to KR2, a compatible sodium ion-proton pump, at 77 K. The first structural study of the functional cycle showed that the structure and structural changes in the primary processes of KR2 are common to all microbial rhodopsins. The red shifted K formation (KR2K) was accompanied by retinal photoisomerization from an all-trans to a 13-cis form, resulting in a distorted retinal chromophore. The observed hydrogen out-of-plane vibrations were H/D exchangeable, indicating that the chromophore distortion by retinal isomerization is located near the Schiff base region in KR2. This tendency was also the case for bacteriorhodopsin and halorhodopsin but not the case for sensory rhodopsin I and II. Therefore, ion pumps such as proton, chloride, and sodium pumps exhibit local structural perturbations of retinal at the Schiff base moiety, while photosensors show more extended structural perturbations of retinal. The retinal Schiff base of KR2 forms a hydrogen bond that is stronger than in BR. KR2 possesses more protein-bound water molecules than other microbial rhodopsins and contains strongly hydrogen-bonded water (O-D stretch at 2333 cm(-1) in D2O). The light-induced difference FTIR spectra at 77 K were identical between the two states functioning as light-driven sodium ion and proton pumps, indicating that the structural changes in the primary processes are identical between different ion pump functions in KR2. In other words, it is unknown which ions are transported by molecules when they absorb photons and photoisomerize. It is likely that the relaxation processes from the K state lead to an alternative function, namely a sodium

  17. Clostridium difficile Infection and Proton Pump Inhibitor Use in Hospitalized Pediatric Cystic Fibrosis Patients

    Directory of Open Access Journals (Sweden)

    John F. Pohl

    2011-01-01

    Full Text Available Children with cystic fibrosis (CF often take proton pump inhibitors (PPIs, which helps improve efficacy of fat absorption with pancreatic enzyme replacement therapy. However, PPI use is known to be associated with Clostridium difficile-(C. diff- associated diarrhea (CDAD. We retrospectively evaluated the incidence of C. diff infection from all pediatric hospital admissions over a 5-year period at a single tertiary children's hospital. We found significantly more C. diff-positive stool tests in hospitalized patients with CF compared to patients with no diagnosis of CF. However, use of a PPI was not associated with an increased risk of CDAD in hospitalized CF patients. In summary, C. diff infection is more common in hospitalized pediatric CF patients although PPI use may not be a risk factor for CDAD development in this patient population.

  18. The potential drug-drug interaction between proton pump inhibitors and warfarin

    DEFF Research Database (Denmark)

    Henriksen, Daniel Pilsgaard; Stage, Tore Bjerregaard; Hansen, Morten Rix

    2015-01-01

    BACKGROUND: Proton pump inhibitors (PPIs) have been suggested to increase the effect of warfarin, and clinical guidelines recommend careful monitoring of international normalized ratio (INR) when initiating PPI among warfarin users. However, this drug-drug interaction is sparsely investigated...... before and after PPI initiation. Sensitivity analyses revealed no differences among individual PPIs. CONCLUSIONS: We found no evidence of a clinically meaningful drug-drug interaction between PPIs and warfarin in a Northern European patient population of unselected patients from an everyday outpatient...... and outpatient clinics and their use of prescription drugs. Data were analyzed in 2015. We assessed INR, warfarin dose, and dose/INR ratio before and after initiating PPI treatment using the paired student's t-test. RESULTS: We identified 305 warfarin users initiating treatment with PPIs. The median age was 71...

  19. The association of proton pump inhibitors and chronic kidney disease: cause or confounding?

    Science.gov (United States)

    Li, Tingting; Xie, Yan; Al-Aly, Ziyad

    2018-02-09

    To discuss whether the recently described relationship between proton pump inhibitor (PPI) use and the risk of adverse kidney outcomes represents a causal relationship or is merely the result of confounding. A wave of observational studies has described an association between PPI use and the risk of development of chronic kidney disease and its progression to end-stage renal disease. The results are generally robust and remarkably consistent across different studies. The application of modern pharmacoepidemiologic methods to estimate the effect of a putative unmeasured or unknown confounder or set of confounders on the relationship of PPI use and risk of adverse renal outcomes suggests that confounding is unlikely to explain away the reported association. The constellation of evidence from all available studies suggests that PPI use is associated with increased risk of adverse kidney outcomes. Exercising vigilance in the use of PPI is warranted.

  20. Cost-Effectiveness of Intravenous Proton Pump Inhibitors in High-Risk Bleeders

    Directory of Open Access Journals (Sweden)

    Sander Veldhuyzen van Zanten

    2004-01-01

    Full Text Available There is unequivocal evidence that proton pump inhibitors (PPIs are currently the most effective acid suppressive agents available. Intravenous (IV formulations have been developed, although only IV pantoprazole is available in Canada. In patients presenting with serious upper gastrointestinal (GI bleeding due to duodenal or gastric ulcers, it has always been believed that IV administration of acid-lowering agents would improve clinical outcomes. The reason behind this thinking is twofold. First, there is in vitro evidence that formed clots are more stable at or near neutral pH (1. Second, by administering the agent intravenously, suppression of acid production is achieved much more quickly, thereby promoting more rapid healing of the ulcer and reducing the risk of persistent or recurrent bleeding. Interestingly and surprisingly, however, the data for intravenous H2-blockers have been disappointing (2. This failure to demonstrate clinical benefit has never been fully explained.

  1. [Proton Pump Inhibitor and High-dose Methotrexate: Two Cases Reports].

    Science.gov (United States)

    Evrard, Julien; Farnier, Elodie; Carcel, Corine; Lachenal, Florence; Vial, Thierry; Pont, Emmanuelle

    2015-01-01

    Methotrexate (MTX) is a cytotoxic agent prescribed at high dose in treatment of malignancy. Association of MTX to proton pump inhibitor (PPI) is not recommended if doses are more than 20 mg per weeks and only to take into account for smaller doses. Review relate some cases of delayed elimination of methotrexate in patients taking PPI, which increase risk of toxic event. However, currently there is no status quo on interaction between PPI and MTX according to available data. We report two clinical cases illustrating one more time a toxic event to MTX in presence of PPI. In absence of risk/benefit ratio set correctly, an assessment of appropriateness of PPI prescription before MTX therapy can limit an iatrogenic risk. © 2015 Société Française de Pharmacologie et de Thérapeutique.

  2. Esophageal pH-Impedance Monitoring in Patients With Therapy-Resistant Reflux Symptoms : 'On' or 'Off' Proton Pump Inhibitor?

    NARCIS (Netherlands)

    Hemmink, Gerrit J. M.; Bredenoord, Albert J.; Weusten, Bas L. A. M.; Monkelbaan, Jan F.; Timmer, Robin; Smout, Andre J. P. M.

    2008-01-01

    BACKGROUND: In patients with proton pump inhibitor (PPI)-resistant symptoms, ambulatory 24-h pH-impedance monitoring can be used to assess whether a relationship exists between symptoms and reflux episodes. Until now, it is unclear whether combined pH-impedance monitoring in these patients should be

  3. Concomitant use of clopidogrel and proton pump inhibitors: impact on platelet function and clinical outcome- a systematic review

    NARCIS (Netherlands)

    Jaspers Focks, J.; Brouwer, M.A.; Oijen, M.G.H. van; Lanas, A.; Bhatt, D.L.; Verheugt, F.W.A.

    2013-01-01

    BACKGROUND: Clopidogrel as an adjunct to aspirin has improved outcomes after acute coronary syndromes, but laboratory studies suggest a reduced antiplatelet effect when proton pump inhibitors (PPIs) are co-administered. Despite corroborating data from retrospective studies, new clinical data fuel

  4. Use of Proton Pump Inhibitors and Risks of Fundic Gland Polyps and Gastric Cancer : Systematic Review and Meta-analysis

    NARCIS (Netherlands)

    Tran-Duy, An; Spaetgens, Bart; Hoes, Arno W|info:eu-repo/dai/nl/101111762; de Wit, Niek J|info:eu-repo/dai/nl/100525393; Stehouwer, Coen D A

    2016-01-01

    BACKGROUND & AIMS: There have been increasing numbers of case reports and observational studies of adverse events in patients receiving long-term therapy with proton pump inhibitors (PPIs). The effects of PPI therapy on risks of fundic gland polyps (FGPs) and gastric cancer have received

  5. Meta-analysis: the influence of pre-treatment with a proton pump inhibitor on Helicobacter pylori eradication.

    NARCIS (Netherlands)

    Janssen, M.J.R.; Laheij, R.J.F.; Boer, W.A. de; Jansen, J.B.M.J.

    2005-01-01

    BACKGROUND: There is much debate about the influence of pre-treatment with a proton pump inhibitor on Helicobacter pylori eradication. The few studies investigating the influence of pre-treatment on triple and quadruple therapies did not find differences in eradication rates. However, the high

  6. Teaching the Fundamentals of Biological Research with Primary Literature: Learning from the Discovery of the Gastric Proton Pump

    Science.gov (United States)

    Zhu, Lixin

    2011-01-01

    For the purpose of teaching collegians the fundamentals of biological research, literature explaining the discovery of the gastric proton pump was presented in a 50-min lecture. The presentation included detailed information pertaining to the discovery process. This study was chosen because it demonstrates the importance of having a broad range of…

  7. Cost Effectiveness of Gastroprotection with Proton Pump Inhibitors in Older Low-Dose Acetylsalicylic Acid Users in the Netherlands

    NARCIS (Netherlands)

    Chau, S.H.; Sluiter, R.L.; Kievit, W.; Wensing, M.; Teichert, M.; Hugtenburg, J.G.

    2017-01-01

    PURPOSE: The present study aimed to assess the cost effectiveness of concomitant proton pump inhibitor (PPI) treatment in low-dose acetylsalicylic acid (LDASA) users at risk of upper gastrointestinal (UGI) adverse effects as compared with no PPI co-medication with attention to the age-dependent

  8. Cardiovascular and gastrointestinal outcomes in clopidogrel users on proton pump inhibitors: results of a large Dutch cohort study

    NARCIS (Netherlands)

    van Boxel, Ofke S.; van Oijen, Martijn G. H.; Hagenaars, Matthijs P.; Smout, A. J. P. M.; Siersema, Peter D.

    2010-01-01

    OBJECTIVES: Recent studies have raised concerns on the clinical effectiveness of clopidogrel when taken in combination with proton pump inhibitors (PPIs), demonstrating an increase in the occurrence of cardiovascular events. In this study, the association between the co-administration of a PPI and

  9. Cardiovascular and gastrointestinal outcomes in clopidogrel users on proton pump inhibitors: results of a large Dutch cohort study.

    NARCIS (Netherlands)

    Boxel, O.S. van; Oijen, M.G.H. van; Hagenaars, M.P.; Smout, A.J.P.M.; Siersema, P.D.

    2010-01-01

    OBJECTIVES: Recent studies have raised concerns on the clinical effectiveness of clopidogrel when taken in combination with proton pump inhibitors (PPIs), demonstrating an increase in the occurrence of cardiovascular events. In this study, the association between the co-administration of a PPI and

  10. Clopidogrel and proton pump inhibitors--where do we stand in 2012?

    LENUS (Irish Health Repository)

    Drepper, Michael D

    2012-05-14

    Clopidogrel in association with aspirine is considered state of the art of medical treatment for acute coronary syndrome by reducing the risk of new ischemic events. Concomitant treatment with proton pump inhibitors in order to prevent gastrointestinal side effects is recommended by clinical guidelines. Clopidogrel needs metabolic activation predominantly by the hepatic cytochrome P450 isoenzyme Cytochrome 2C19 (CYP2C19) and proton pump inhibitors (PPIs) are extensively metabolized by the CYP2C19 isoenzyme as well. Several pharmacodynamic studies investigating a potential clopidogrel-PPI interaction found a significant decrease of the clopidogrel platelet antiaggregation effect for omeprazole, but not for pantoprazole. Initial clinical cohort studies in 2009 reported an increased risk for adverse cardiovascular events, when under clopidogrel and PPI treatment at the same time. These observations led the United States Food and Drug Administration and the European Medecines Agency to discourage the combination of clopidogrel and PPI (especially omeprazole) in the same year. In contrast, more recent retrospective cohort studies including propensity score matching and the only existing randomized trial have not shown any difference concerning adverse cardiovascular events when concomitantly on clopidogrel and PPI or only on clopidogrel. Three meta-analyses report an inverse correlation between clopidogrel-PPI interaction and study quality, with high and moderate quality studies not reporting any association, rising concern about unmeasured confounders biasing the low quality studies. Thus, no definite evidence exists for an effect on mortality. Because PPI induced risk reduction clearly overweighs the possible adverse cardiovascular risk in patients with high risk of gastrointestinal bleeding, combination of clopidogrel with the less CYP2C19 inhibiting pantoprazole should be recommended.

  11. Normal and proton pump inhibitor-mediated gastrin levels in infants 1 to 11 months old.

    Science.gov (United States)

    Treem, William; Hu, Peter; Sloan, Sheldon

    2013-10-01

    Scant data exist on the normal range of serum gastrin in infants. In phase I and III trials of rabeprazole in gastroesophageal reflux disease, we studied serum gastrin levels in infants 1 to 11 months old, and assessed normal ranges and the effect of acid-suppressive drugs. Overall, 349 treatment-naïve or treatment-experienced (previously exposed to proton pump inhibitors and/or H2-receptor antagonists) infants with gastroesophageal reflux disease were screened for baseline serum gastrin. Repeat gastrin was monitored at early termination or end of study, allowing assessment of 1 to 8 week daily rabeprazole (5- or 10-mg) treatment on gastrin levels. Median (5%-95% range) baseline gastrin was 118 ng/L (39-315) in the treatment-naïve group (n = 251), driven mostly by high levels (121.5 [48-326] ng/L) in the 1- to gastrin levels (152 [48-487] ng/L; P = 0.0011) with no clear difference between previously proton pump inhibitor-exposed and H2-receptor antagonist-exposed groups. At the end of study, mean (standard deviation) levels were unchanged from baseline in infants withdrawn from rabeprazole to placebo (124 [94] ng/L), but elevated from baseline in those continuing treatment with 5-mg (245 [151] ng/L) and 10-mg (332 [222] ng/L) rabeprazole during the study. Gastrin levels in treatment-naïve infants were elevated through 8 months of age. Between 8 and 12 months of age, they declined so that the median level was within the upper limit of the normal adult range (gastrin levels in infants younger than 1 year.

  12. Effectiveness of proton pump inhibitors in the treatment of patients with endoscopic esophagitis.

    Science.gov (United States)

    Gashi, Zaim; Haziri, Adem; Berisha, Drita; Zekaj, Sadik; Polloshka, Aida; Bakalli, Aurora; Juniku, Argjira; Sadriu, Luljeta

    2010-01-01

    Gastroesophageal reflux disease (GERD) is a common disorder, typically diagnosed by a history of chronic heartburn. Proton pump inhibitors (PPIs) eliminate symptoms and heal esophagitis more frequently and more rapidly than other agents. The aims of this study were to evaluate the effectiveness of proton pump inhibitors (PPIs) in terms of symptom resolution and endoscopic healing in patients with erosive reflux disease. In this prospective study we included 380 patients with positive history for the main symptoms of erosive reflux disease. Symptoms were evaluated before and after treatment with PPI on the period of three months and were recorded with heartburn system score and regurgitation score. All patients were classified according to Los Angeles classification for erosive reflux disease, before and after the three months treatment with PPI and were conducted for their healing of erosive oesophagitis in the finish of the treatment. Before the treatment, 95% of patients were with heartburn, 90% with regurgitation and 70% with epigastric pain. Quantification for pyrosis and regurgitation were obtained in each patient. After treatment of these patients with PPIs, resolution for pyrosis was from 95% to 25%, for regurgitation from 90% to 20% and for epigastric pain from 70% to 10%. In 71.67% of patients was found complete healing of erosive oesophagitis and minimal progression in 1.05% of patients. Results of this study showed that PPI treatment of patients with erosive reflux disease can influence on very good symptomatic and mucosal resolution after three months. Epigastric pain was shown not to bee specific for erosive reflux disease.

  13. Use of proton pump inhibitors in general practice: Is it rationale?

    Directory of Open Access Journals (Sweden)

    Nousheen, Tadvi NA, Shareef SM

    2014-03-01

    Full Text Available Background: The incidence of improper use of PPIs varies from 40-70% in various studies. Initiation and the continuous use of these drugs without correct indications will result in significant cost to the patient. The present study was planned with the aim of finding out the rational use of PPIs in the in patients of a rural tertiary care hospital. Objectives: To assess indications of use of PPIs along with their dose, frequency, rationality of treatment, safety and efficacy. Methods: Prospective observational drug-utilization study of PPIs was conducted for two months in the inpatients of General Medicine and General Surgery wards. The sample size of study was (n=100. The case sheets of the patients were reviewed for PPIs prescription and relevant data was taken. A five point Likert scale with validated Reflux Disease Diagnostic Questionnaire (RDQhaving 12 items was used for evaluating symptoms score for assessing efficacy of PPIs. Results: A total of 46.72% inpatients were on proton pump inhibitors, in surgery(47.52% and medicine wards (46.01%. The indications for PPIs therapy were acute gastritis (4% , Gastro Esophageal reflux disease (5% , Duodenal ulcer(1% , co-administration with Non Steroidal Anti-Inflammatory Drugs(32%. PPIs were prescribed irrationally in 58 % of patients without any valid indication. The incidence of polypharmacy was high, average number of drugs per prescription was 4.93. Antimicrobials were the most common drugs used in (71%. CONCLUSION: Proton pump inhibitors should be used more judiciously and awareness should be created among the clinicians in the hospital so that appropriate prescription of PPIs will improve the patient care at low cost.

  14. Blood Pressure-Lowering Effect of Orally Ingested Nitrite Is Abolished by a Proton Pump Inhibitor.

    Science.gov (United States)

    Montenegro, Marcelo F; Sundqvist, Michaela L; Larsen, Filip J; Zhuge, Zhengbing; Carlström, Mattias; Weitzberg, Eddie; Lundberg, Jon O

    2017-01-01

    Inorganic nitrate and nitrite from dietary and endogenous sources are metabolized to NO and other bioactive nitrogen oxides that affect blood pressure. The mechanisms for nitrite bioactivation are unclear, but recent studies in rodents suggest that gastric acidity may influence the systemic effects of this anion. In a randomized, double-blind, placebo-controlled crossover study, we tested the effects of a proton pump inhibitor on the acute cardiovascular effects of nitrite. Fifteen healthy nonsmoking, normotensive subjects, aged 19 to 39 years, were pretreated with placebo or esomeprazole (3×40 mg) before ingesting sodium nitrite (0.3 mg kg(-1)), followed by blood pressure monitoring. Nitrite reduced systolic blood pressure by a maximum of 6±1.3 mm Hg when taken after placebo, whereas pretreatment with esomeprazole blunted this effect. Peak plasma nitrite, nitrate, and nitroso species levels after nitrite ingestion were similar in both interventions. In 8 healthy volunteers, we then infused increasing doses of sodium nitrite (1, 10, and 30 nmol kg(-1) min(-1)) intravenously. Interestingly, although plasma nitrite peaked at similar levels as with orally ingested nitrite (≈1.8 µmol/L), no changes in blood pressure were observed. In rodents, esomeprazole did not affect the blood pressure response to the NO donor, DEA NONOate, or vascular relaxation to nitroprusside and acetylcholine, demonstrating an intact downstream NO-signaling pathway. We conclude that the acute blood pressure-lowering effect of nitrite requires an acidic gastric environment. Future studies will reveal if the cardiovascular complications associated with the use of proton pump inhibitors are linked to interference with the nitrate-nitrite-NO pathway. © 2016 American Heart Association, Inc.

  15. Clopidogrel and proton pump inhibitors - where do we stand in 2012?

    Science.gov (United States)

    Drepper, Michael D; Spahr, Laurent; Frossard, Jean Louis

    2012-01-01

    Clopidogrel in association with aspirine is considered state of the art of medical treatment for acute coronary syndrome by reducing the risk of new ischemic events. Concomitant treatment with proton pump inhibitors in order to prevent gastrointestinal side effects is recommended by clinical guidelines. Clopidogrel needs metabolic activation predominantly by the hepatic cytochrome P450 isoenzyme Cytochrome 2C19 (CYP2C19) and proton pump inhibitors (PPIs) are extensively metabolized by the CYP2C19 isoenzyme as well. Several pharmacodynamic studies investigating a potential clopidogrel-PPI interaction found a significant decrease of the clopidogrel platelet antiaggregation effect for omeprazole, but not for pantoprazole. Initial clinical cohort studies in 2009 reported an increased risk for adverse cardiovascular events, when under clopidogrel and PPI treatment at the same time. These observations led the United States Food and Drug Administration and the European Medecines Agency to discourage the combination of clopidogrel and PPI (especially omeprazole) in the same year. In contrast, more recent retrospective cohort studies including propensity score matching and the only existing randomized trial have not shown any difference concerning adverse cardiovascular events when concomitantly on clopidogrel and PPI or only on clopidogrel. Three meta-analyses report an inverse correlation between clopidogrel-PPI interaction and study quality, with high and moderate quality studies not reporting any association, rising concern about unmeasured confounders biasing the low quality studies. Thus, no definite evidence exists for an effect on mortality. Because PPI induced risk reduction clearly overweighs the possible adverse cardiovascular risk in patients with high risk of gastrointestinal bleeding, combination of clopidogrel with the less CYP2C19 inhibiting pantoprazole should be recommended. PMID:22611308

  16. Lack of proton pump inhibitor trial prior to commencing therapy for eosinophilic esophagitis is common in the community.

    Science.gov (United States)

    Whitson, M J; Lynch, K L; Yang, Y-X; Metz, D C; Falk, G W

    2017-12-22

    Eosinophilic esophagitis is characterized by eosinophil inflammation restricted to the esophagus and the resulting symptoms of esophageal dysfunction. Critical to the diagnosis of eosinophilic esophagitis is a trial of proton pump inhibitor therapy to exclude alternative causes of esophageal eosinophilia such as proton pump inhibitor-responsive esophageal eosinophilia. While consensus guidelines recommend a proton pump inhibitor trial prior to diagnosis, little is known about its implementation in clinical practice. The primary aim of this study is to assess the frequency of proton pump inhibitor trial prior to the diagnosis of eosinophilic esophagitis in community practice. The secondary aim is to assess the frequency of other treatments for eosinophilic esophagitis, including topical steroids and/or dietary therapy, in patients who did not undergo a proton pump inhibitor trial prior to diagnosis or who had an alternative diagnosis to eosinophilic esophagitis upon completed workup. We conducted a single-center, case series of patients referred to the Hospital of the University of Pennsylvania for eosinophilic esophagitis management between 2010 and 2015. This case series consisted of 125 patients who were referred from community practitioners with a presumptive diagnosis of eosinophilic esophagitis. Upon review, 90 out of 125 (72%) patients had not had a proton pump inhibitor trial or esophageal pH testing prior to the diagnosis of eosinophilic esophagitis being made. Of these patients, 77.8% (70/90) had already received either topical steroid or dietary therapy for presumed eosinophilic esophagitis. Of the 125 patients initially diagnosed with eosinophilic esophagitis, 32 (25.6%) were found to have an alternative diagnosis, and 79.2% of this subset of patients (25/32) had previously received topical steroid or dietary therapy. This study demonstrates that a substantial number of patients with presumed eosinophilic esophagitis have not had a proton pump inhibitor

  17. Up in Smoke: Uncovering a Lack of Evidence for Proton Pump Inhibitors as a Source of Tetrahydrocannibol Immunoassay False Positives.

    Science.gov (United States)

    Powers, Jennifer L; Rasmussen, Natalie N; Hurst, Dow; Strathmann, Frederick G

    2017-11-08

    It is recommended that positives in immunoassay drug screens be followed up with more specific confirmatory testing. The drug package insert for pantoprazole mentions reports of false-positive urine screening tests for tetrahydrocannabinol in patients receiving proton pump inhibitors, but no method details or data are given, referenced, or found in literature searches. Thus, we investigated this using our laboratory's assay. A spiked sample and samples from 32 patients taking a proton pump inhibitor were analyzed using the EMIT II Plus Cannabinoid assay with a 20 ng/mL cutoff. Additionally, we examined urine samples from 50 patients with false-positive or low-positive screens for evidence of a proton pump inhibitor. To determine whether O-desmethyl pantoprazole sulfate, the major metabolite, shares any structural or electrostatic similarity to suggest a basis for cross-reactivity in the immunoassay, we used computational techniques for analyses. Molecular electrostatic potential energy (MEP) maps were calculated for the global minimum conformers, and the maximum common substructure Tanimoto similarity was calculated for the modeled compounds. Neither the spiked sample nor the patient samples were found to screen positive. None of the false-positive or low-positive screens were found to contain a proton pump inhibitor. Computational studies showed very little similarity in shape or electrostatics between the two molecules. We find no supporting evidence of pantoprazole as the cause of false positives in the EMIT II Plus Cannabinoid assay and caution the use of proton pump inhibitors as an explanation for tetrahydrocannabinol immunoassay false positives.

  18. E3710, a new proton pump inhibitor, with a long-lasting inhibitory effect on gastric acid secretion.

    Science.gov (United States)

    Kodama, Kotaro; Fujisaki, Hideaki; Kubota, Atsuhiko; Kato, Hiroshi; Hirota, Kazuo; Kuramochi, Hiroko; Murota, Miki; Tabata, Yoshikuni; Ueda, Masato; Harada, Hitoshi; Kawahara, Tetsuya; Shinoda, Masanobu; Watanabe, Nobuhisa; Iida, Daisuke; Terauchi, Hiroki; Yasui, Sou; Miyazawa, Shuhei; Nagakawa, Junichi

    2010-08-01

    We have investigated the pharmacology of sodium (R)-2-[4-(2,2-dimethyl-1,3-dioxan-5-yl) methoxy-3,5-dimethylpyridin-2-yl]methylsulfinyl-1H-benzimidazol (E3710), a new proton pump inhibitor (PPI), and its effect on gastric acid secretion. E3710 irreversibly inhibited H(+),K(+)-ATPase activity in pig gastric vesicles with an acidic internal environment with an IC(50) of 0.28 microM. Administration of E3710 (0.1, 0.2, 0.4, and 0.8 mg/kg; n = 6) intraduodenally in a gastric fistula model in dogs inhibited histamine-stimulated gastric acid secretion at 0 to 2 and 24 to 26 h after administration with ED(50) values of 0.18 and 0.22 mg/kg, respectively. The inhibition by E3710 was 2.3 times more potent than that of another representative PPI, esomeprazole (0.2, 0.4, 0.8, and 1.6 mg/kg; n = 6) at 0 to 2 h after administration (ED(50) = 0.40 mg/kg) and 2.8 times more potent at 24 to 26 h (ED(50) = 0.71 mg/kg). In the gastric fistula dogs, the intragastric pH was >or=4 for 17% (n = 27) of a 24-h period with vehicle alone, but when E3710 was administered, at 0.2 (n = 4), 0.4 (n = 8), and 0.8 mg/kg (n = 5), the pH was >or=4 for 40, 79, and 88% of a day, respectively. The corresponding values for esomeprazole at 0.8 (n = 4) and 1.6 mg/kg (n = 8) were 55 and 59%, respectively. In a crossover study with vehicle, E3710 at 0.4 mg/kg and esomeprazole at 1.6 mg/kg (n = 6), E3710 increased the intragastric pH to >4 for 82% of a day compared with 61% of a day with esomeprazole. These results show that E3710 is a long-acting inhibitor of gastric acid secretion and a promising novel therapy for acid-related diseases, such as gastroesophageal reflux disease.

  19. Biophysical comparison of ATP-driven proton pumping mechanisms suggests a kinetic advantage for the rotary process depending on coupling ratio

    OpenAIRE

    Anandakrishnan, Ramu; Zuckerman, Daniel M.

    2017-01-01

    ATP-driven proton pumps, which are critical to the operation of a cell, maintain cytosolic and organellar pH levels within a narrow functional range. These pumps employ two very different mechanisms: an elaborate rotary mechanism used by V-ATPase H+ pumps, and a simpler alternating access mechanism used by P-ATPase H+ pumps. Why are two different mechanisms used to perform the same function? Systematic analysis, without parameter fitting, of kinetic models of the rotary, alternating access an...

  20. [Safety and interactions of proton pump inhibitors: lessons learned in millions of patients].

    Science.gov (United States)

    Esplugues, Juan V; Martí-Cabrera, Miguel

    2010-05-01

    After many years of widespread use, proton pump inhibitors (PPI) have been demonstrated to be relatively safe. The most frequently associated adverse reactions are mild with scarce clinical effects. These agents produce hypergastrinemia but this adverse effect has not been related to the development of malignancies. PPI seem to facilitate certain bacterial infections in the gastrointestinal and respiratory tracts. However, these infections are easily treated and therefore do not limit the prescription of PPI. From the pharmacokinetic point of view, the possibility of interactions with other drugs metabolized by the cytochrome P450 system has been described but these interactions generally seem to have little clinical or therapeutic importance. However, regulatory agencies are currently stressing the hypothetical interaction between PPI (especially omeprazole) and clopidogrel, which reduces the latter's antiplatelet effect. Although this recommendation should be followed, this interaction should be specifically evaluated to determine its clinical effect and the possible alternatives in patients at risk of gastrointestinal bleeding. Lastly, the present article reviews PPI administration in special, currently debated situations, such as in pregnant or breastfeeding women. Copyright © 2010 Elsevier España S.L. All rights reserved.

  1. Proton Pump Inhibitors in Cardiovascular Disease: Drug Interactions with Antiplatelet Drugs.

    Science.gov (United States)

    Würtz, Morten; Grove, Erik L

    2017-01-01

    Aspirin and P2Y12 receptor antagonists are widely used across the spectrum of cardiovascular diseases. Upper gastrointestinal complications, including ulcer and bleeding, are relatively common during antiplatelet treatment and, therefore, concomitant proton pump inhibitor (PPI) treatment is often prescribed.PPIs provide gastroprotection by changing the intragastric milieu, essentially by raising intragastric pH. In recent years, it has been heavily discussed whether PPIs may reduce the cardiovascular protection by aspirin and, even more so, clopidogrel. Pharmacodynamic and pharmacokinetic studies suggested an interaction between PPIs and clopidogrel, and subsequent clinical studies were conducted to evaluate the clinical impact of this interaction. More recently, it was reported that PPIs may also attenuate the antiplatelet effect of aspirin. This may be clinically important, because a fixed combination of aspirin and a PPI (esomeprazole) has recently been approved and because aspirin is the most widely used drug in patients with cardiovascular disease. The antiplatelet effect of the new P2Y12 receptor antagonists, ticagrelor and prasugrel, seems less influenced by PPI co-treatment.Given the large number of patients treated with antithrombotic drugs and PPIs, even a minor reduction of platelet inhibition potentially carries considerable clinical impact. The present book chapter summarizes the evidence regarding the widespread use of platelet inhibitors and PPIs in combination. Moreover, it outlines current evidence supporting or opposing drug interactions between these drugs and discusses clinical implications.

  2. Efficacy and safety of proton pump inhibitors in the management of pediatric gastroesophageal reflux disease.

    Science.gov (United States)

    Tjon, James A; Pe, Michael; Soscia, Joanna; Mahant, Sanjay

    2013-09-01

    Proton pump inhibitors (PPIs) are commonly prescribed to infants and children for managing gastroesophageal reflux disease (GERD). Recently published literature illustrates conflicting evidence on the efficacy of PPIs in infants and children. Randomized controlled trials and systematic reviews have demonstrated a lack of efficacy of PPIs, specifically in young infants. Furthermore, emerging evidence also suggests that PPIs are not as benign as once thought, with newer data implicating a potential association of PPIs with an increased risk of respiratory tract infections, gastrointestinal infections, bone fractures, hypomagnesemia, and the occurrence of rebound hyperacidity after discontinuation of PPI therapy. To summarize the emerging data in children, we reviewed the literature to assess the efficacy and safety of PPIs in managing pediatric GERD. Despite conflicting evidence on the efficacy of PPIs, most studies in children demonstrated some benefit when compared with placebo. With respect to the safety of PPIs in children, only a few small studies and case reports indicated a potential association of PPIs with an increased risk of respiratory tract or gastrointestinal infections, bone fractures, and hypomagnesemia; however, many of those studies had their own limitations. From the review, it is clear that further well-designed trials and observational studies are needed to shed more light on the efficacy and safety of PPIs in the pediatric population. © 2013 Pharmacotherapy Publications, Inc.

  3. Can proton pumping by SERCA enhance the regulatory role of phospholamban and sarcolipin?

    Science.gov (United States)

    Becucci, Lucia; Foresti, Maria Luisa; Schwan, Adrian; Guidelli, Rolando

    2013-11-01

    The effect of the incorporation of phosphorylated phospholamban (pPLN) and sarcolipin (SLN) in mercury-supported self-assembled lipid monolayers and in lipid bilayers tethered to mercury via a hydrophilic spacer was investigated by voltammetric techniques and electrochemical impedance spectroscopy. It was shown that pPLN and SLN do not permeabilize lipid bilayers toward ions at physiological pH. However, they exert a permeabilizing action toward inorganic monovalent cations such as K(+) and Tl(+), but not toward divalent cations such as Ca(2+) and Cd(2+), following a small decrease in pH. This behavior can be associated with their regulatory action on the Ca-ATPase of the sarcoplasmic reticulum (SERCA). SERCA pumps two Ca(2+) ions from the cytosol to the lumen of the sarcoplasmic reticulum (SR) and two protons in the opposite direction, causing a transient decrease of pH in the immediate vicinity of its cytoplasmic domain. This decrease is expected to activate the liberated pPLN molecules and SLN to make the SR membrane leakier toward K(+) and Na(+) and the SLN ion channel to translocate small inorganic anions, such as Cl(-). The effect of pPLN and SLN, which becomes synergic when they are both present in the SR membrane, is expected to favor a rapid equilibration of ions on both sides of the membrane. © 2013.

  4. Omeprazole, a gastric proton pump inhibitor, inhibits melanogenesis by blocking ATP7A trafficking.

    Science.gov (United States)

    Matsui, Mary S; Petris, Michael J; Niki, Yoko; Karaman-Jurukovska, Nevena; Muizzuddin, Neelam; Ichihashi, Masamitsu; Yarosh, Daniel B

    2015-03-01

    Omeprazole is a proton pump inhibitor used in the treatment of peptic ulcer disease and gastrosophageal reflux disease and acts by irreversibly blocking ATP4A, a P-type H+/K+ ATPase in gastric parietal cells. We found that omeprazole and its closely related congeners inhibited melanogenesis at micromolar concentrations in B16 mouse melanoma cells, normal human epidermal melanocytes, and in a reconstructed human skin model. Omeprazole topically applied to the skin of UV-irradiated human subjects significantly reduced pigment levels after 3 weeks compared with untreated controls. Omeprazole had no significant inhibitory effect on the activities of purified human tyrosinase or on the mRNA levels of tyrosinase, dopachrome tautomerase, Pmel17, or MITF mRNA levels. Although melanocytes do not express ATP4A, they do express ATP7A, a copper transporting P-type ATPase in the trans-Golgi network that is required for copper acquisition by tyrosinase. ATP7A relocalization from the trans-Golgi network to the plasma membrane in response to elevated copper concentrations in melanocytes was inhibited by omeprazole. Omeprazole treatment increased the proportion of EndoH sensitive tyrosinase, indicating that tyrosinase maturation was impaired. In addition, omeprazole reduced tyrosinase protein abundance in the presence of cycloheximide, suggestive of increased degradation. Our findings are consistent with the hypothesis that omeprazole reduces melanogenesis by inhibiting ATP7A and by enhancing degradation of tyrosinase.

  5. Influence of different proton pump inhibitors on the pharmacokinetics of voriconazole.

    Science.gov (United States)

    Qi, Fang; Zhu, Liqin; Li, Na; Ge, Tingyue; Xu, Gaoqi; Liao, Shasha

    2017-04-01

    This study aimed to determine the influence of proton pump inhibitors (PPIs) on the pharmacokinetics of voriconazole and to characterise potential drug-drug interactions (DDIs) between voriconazole and various PPIs (omeprazole, esomeprazole, lansoprazole and rabeprazole). Using adjusted physicochemical data and the pharmacokinetic (PK) parameters of voriconazole and PPIs, physiologically based pharmacokinetic (PBPK) models were built and were verified in healthy subjects using GastroPlus TM to predict the plasma concentration-time profiles of voriconazole and PPIs. These models were then used to assess potential DDIs for voriconazole when administered with PPIs. The results indicated the PBPK model-simulated plasma concentration-time profiles of both voriconazole and PPIs were consistent with the observed profiles. In addition, the DDI simulations suggested that the PK values of voriconazole increased to various degrees when combined with several PPIs. The area under the plasma concentration-time curve for the time of the simulation (AUC 0- t ) of voriconazole was increased by 39%, 18%, 12% and 1% when co-administered with omeprazole, esomeprazole, lansoprazole and rabeprazole, respectively. Omeprazole was the most potent CYP2C19 inhibitor tested, whereas rabeprazole had no influence on voriconazole (omeprazole > esomeprazole > lansoprazole > rabeprazole). However, in consideration of the therapeutic concentration range, dosage adjustment of voriconazole is unnecessary regardless of which PPI was co-administered. Copyright © 2017 Elsevier B.V. and International Society of Chemotherapy. All rights reserved.

  6. In Vitro Study of the Variable Effects of Proton Pump Inhibitors on Voriconazole

    Science.gov (United States)

    Niece, Krista L.; Boyd, Natalie K.

    2015-01-01

    Voriconazole is a broad-spectrum antifungal agent used for the treatment of severe fungal infections. Maintaining therapeutic concentrations of 1 to 5.5 μg/ml is currently recommended to maximize the exposure-response relationship of voriconazole. However, this is challenging, given the highly variable pharmacokinetics of the drug, which includes metabolism by cytochrome P450 (CYP450) isotypes CYP2C19, CYP3A4, and CYP2C9, through which common metabolic pathways for many medications take place and which are also expressed in different isoforms with various metabolic efficacies. Proton pump inhibitors (PPIs) are also metabolized through these enzymes, making them competitive inhibitors of voriconazole metabolism, and coadministration with voriconazole has been reported to increase total voriconazole exposure. We examined the effects of five PPIs (rabeprazole, pantoprazole, lansoprazole, omeprazole, and esomeprazole) on voriconazole concentrations using four sets of human liver microsomes (HLMs) of different CYP450 phenotypes. Overall, the use of voriconazole in combination with any PPI led to a significantly higher voriconazole yield compared to that achieved with voriconazole alone in both pooled HLMs (77% versus 59%; P voriconazole yield from that at the baseline after PPI exposure in pooled microsomes ranged from 22% with pantoprazole to 51% with esomeprazole. Future studies are warranted to confirm whether and how the deliberate coadministration of voriconazole and PPIs can be used to boost voriconazole levels in patients with difficult-to-treat fungal infections. PMID:26124167

  7. Is there an overprescription of proton pump inhibitors in oncohematologic patients undergoing ambulatory oncospecific treatment?

    Directory of Open Access Journals (Sweden)

    Meritxell Pujal Herranz

    2016-09-01

    Full Text Available Objective: The aim of this study is to evaluate the prevalence of proton pump inhibitors (PPIs prescription, and the level of adequacy of the indication of these drugs in oncohematologic patients under ambulatory oncoespecific treatment. Method: An observational descriptive study in oncohematologic patients under ambulatory oncoespecific treatment. A protocol for the rational use of PPI targeted to oncohematologic patients based on the PPI protocol of our hospital was designed. Patients under active treatment with PPIs were quantified and the appropriateness of their indications evaluated. Results: 111 patients (71 oncologic and 40 hematologic were included. 56% of all oncologic patients and 63% of all hematologic patients were under active treatment with PPIs. After reviewing the indications for PPI in all patients, 72% of oncologic and 12% of hematologic patients did not present evidence justifying treatment with these drugs. Conclusion: It is important the pharmacist to detect unappropriated prescriptions of PPIs, especially among oncologic patients, and to promote a deprescription of these drugs

  8. A Review of the Novel Application and Potential Adverse Effects of Proton Pump Inhibitors.

    Science.gov (United States)

    Yu, Li-Yuan; Sun, Lu-Ning; Zhang, Xue-Hui; Li, Yue-Qi; Yu, Lei; Yuan, Zi-Qing-Yun; Meng, Ling; Zhang, Hong-Wen; Wang, Yong-Qing

    2017-05-01

    Proton pump inhibitors (PPIs) are known as a class of pharmaceutical agents that target H+/K+-ATPase, which is located in gastric parietal cells. PPIs are widely used in the treatment of gastric acid-related diseases including peptic ulcer disease, erosive esophagitis and gastroesophageal reflux disease, and so on. These drugs present an excellent safety profile and have become one of the most commonly prescribed drugs in primary and specialty care. Except for gastric acid-related diseases, PPIs can also be used in the treatment of Helicobacter pylori infection, viral infections, respiratory system diseases, cancer and so on. Although PPIs are mainly used short term in patients with peptic ulcer disease, nowadays these drugs are increasingly used long term, and frequently for a lifetime, for instance in patients with typical or atypical symptoms of gastroesophageal reflux disease and in NSAID or aspirin users at risk of gastrotoxicity and related complications including hemorrhage, perforation and gastric outlet obstruction. Long-term use of PPIs may lead to potential adverse effects, such as osteoporotic fracture, renal damage, infection (pneumonia and clostridium difficile infection), rhabdomyolysis, nutritional deficiencies (vitamin B12, magnesium and iron), anemia and thrombocytopenia. In this article, we will review some novel uses of PPIs in other fields and summarize the underlying adverse reactions.

  9. Inulin significantly improves serum magnesium levels in proton pump inhibitor-induced hypomagnesaemia.

    Science.gov (United States)

    Hess, M W; de Baaij, J H F; Broekman, M; Bisseling, T M; Haarhuis, B; Tan, A; Te Morsche, R; Hoenderop, J G J; Bindels, R J M; Drenth, J P H

    2016-06-01

    Proton pump inhibitors (PPI) are among the most widely prescribed drugs to treat gastric acid-related disorders. PPI-induced hypomagnesaemia, a defect in intestinal absorption of Mg(2+) , can be a severe side effect of chronic PPI use. To restore serum Mg(2+) concentrations in PPI-induced hypomagnesaemia patients by dietary supplementation with inulin fibres. Eleven patients with PPI-induced hypomagnesaemia and 10 controls were treated with inulin (20 g/day). Each trial consisted of two cycles of 14-day inulin treatment followed by a washout period of 14 days. Patients continued to use their PPI. Serum Mg(2+) levels served as the primary endpoint. Inulin significantly enhanced serum Mg(2+) levels from 0.60 to 0.68 mmol/L in PPI-induced hypomagnesaemia patients, and from 0.84 to 0.93 mmol/L in controls. As a consequence 24 h urinary Mg(2+) excretion was significantly increased in patients with PPI-induced hypomagnesaemia (0.3-2.2 mmol/day). Symptoms related to hypomagnesaemia, including muscle cramps and paraesthesia, were reduced during intervention with inulin. Inulin increases serum Mg(2+) concentrations under PPI maintenance in patients with PPI-induced hypomagnesaemia. © 2016 John Wiley & Sons Ltd.

  10. A Benzimidazole Proton Pump Inhibitor Increases Growth and Tolerance to Salt Stress in Tomato

    Directory of Open Access Journals (Sweden)

    Michael J. Van Oosten

    2017-07-01

    Full Text Available Pre-treatment of tomato plants with micromolar concentrations of omeprazole (OP, a benzimidazole proton pump inhibitor in mammalian systems, improves plant growth in terms of fresh weight of shoot and roots by 49 and 55% and dry weight by 54 and 105% under salt stress conditions (200 mM NaCl, respectively. Assessment of gas exchange, ion distribution, and gene expression profile in different organs strongly indicates that OP interferes with key components of the stress adaptation machinery, including hormonal control of root development (improving length and branching, protection of the photosynthetic system (improving quantum yield of photosystem II and regulation of ion homeostasis (improving the K+:Na+ ratio in leaves and roots. To our knowledge OP is one of the few known molecules that at micromolar concentrations manifests a dual function as growth enhancer and salt stress protectant. Therefore, OP can be used as new inducer of stress tolerance to better understand molecular and physiological stress adaptation paths in plants and to design new products to improve crop performance under suboptimal growth conditions.Highlight: Omeprazole enhances growth of tomato and increases tolerance to salinity stress through alterations of gene expression and ion uptake and transport.

  11. Serum magnesium and proton-pump inhibitors use: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Gustavo Adolpho Moreira Faulhaber

    2013-06-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate the association of serum magnesium levels with proton pump inhibitors (PPIs use and other factors. METHODS: This was a cross-sectional study of 151 patients admitted with acute diseases in the Internal Medicine Division of the Hospital de Clinicas de Porto Alegre, after the exclusion of conditions that are commonly associated with hypomagnesemia: diarrhea; vomiting; chronic alcohol use; severely uncompensated diabetes mellitus; and chronic use of laxatives, diuretics or other drugs causing magnesium deficiency. RESULTS: All patients had normal serum magnesium levels. Serum albumin and creatinine levels were positively associated with serum magnesium levels, after adjusting for confounders. There was no difference between mean serum magnesium levels of PPI users and non-users, nor between men and women; there was also no correlation among age, serum phosphorus, and potassium levels with serum magnesium levels. Limitations of this study include the absence of an instrument for measuring adherence to PPI use and the sample size. CONCLUSION: The association of PPI use and hypomagnesemia is uncommon. Congenital defects in the metabolism of magnesium may be responsible for hypomagnesemia in some patients using this drug class.

  12. Proton pump inhibitors overuse: only inappropriate prescriptions or further iatrogenic damage?

    Directory of Open Access Journals (Sweden)

    Mario Visconti

    2015-09-01

    Full Text Available Proton pump inhibitors (PPIs are the most potent drugs for reducing gastric acid secretion; so, since their release in the late 1980s, they have been recommended as the first therapeutic choice for many gastroesophageal diseases, risk reduction in or healing of non-steroidal anti-inflammatory drugs-associated ulcer disease and stress ulcer prophylaxis in intensive care unit patients. Thus PPIs account for a significant proportion of pharmaceutical health-care expenditure. Much of this high expenditure results from overuse of PPIs in account of inappropriate indications or prolongation of therapies for excessive time compared to real need. PPIs overutilization occurs in all medical care settings: in the majority of hospitalized patients with low risks for gastrointestinal bleeding, in patients healed at discharge from hospital, in outpatients in ambulatory practice. However potential adverse effects associated with PPIs therapy have been described, including enteric (especially by Clostridium difficile in elderly patients and pneumonia infections, nutritional deficiencies, rebound acid hypersecretion, acute interstitial nephritis, gastric neoplasms, bone fractures. Caution is required for some coprescription, particularly with clopidogrel.

  13. Proton pump inhibitors as a possible cause of vitiligo: an in vivo and in vitro study.

    Science.gov (United States)

    Shin, J M; Lee, J Y; Lee, D Y; Yoon, T Y; Lee, J C; Lim, E H; Sohn, K C; Lee, Y H; Im, M; Seo, Y J; Kim, C D; Lee, J H; Lee, Y

    2014-11-01

    Vitiligo is an acquired depigmentation disorder of melanocytes. Recently, some clinical reports have suggested that proton pump inhibitors (PPIs) may worsen vitiligo, but their effects on melanocytes have yet to be elucidated. We investigated the effect of PPIs on melanogenesis in vivo and in vitro. We examined the effect of PPIs on melanogenesis in B16 murine melanoma cells by measuring melanin content and tyrosinase (TYR) activity. TYR and tyrosinase-related protein-1 (TRP-1) were monitored by western blotting. Finally, a PPI was applied to zebrafish embryos to investigate its in vivo effect on pigmentation. In agreement with our clinical experience of worsened vitiligo after PPI treatment, PPIs decreased both melanin content and TYR activity. Western blotting showed that PPIs decreased TYR and TRP-1 protein levels. In the zebrafish test, PPIs inhibited body pigmentation in a dose-dependent manner. These results suggest that the functional inhibition of melanization by PPIs may induce or aggravate vitiligo lesions in genetically predisposed patients. © 2013 European Academy of Dermatology and Venereology.

  14. Association of Proton Pump Inhibitor (PPI Use with Energy Intake, Physical Activity, and Weight Gain

    Directory of Open Access Journals (Sweden)

    Jennifer L. Czwornog

    2015-10-01

    Full Text Available Studies suggest proton pump inhibitor (PPI use impacts body weight regulation, though the effect of PPIs on energy intake, energy extraction, and energy expenditure is unknown. We used data on 3073 eligible adults from the National Health and Nutrition Examination Survey (NHANES. Medication use, energy intake, diet composition, and physical activity were extracted from NHANES. Multivariate regression models included confounding variables. Daily energy intake was similar between PPI users and non-users (p = 0.41. Diet composition was similar between the two groups, except that PPI users consumed a slightly greater proportion of calories from fat (34.5% vs. 33.2%; p = 0.02. PPI users rated themselves as being as physically active as their age/gender-matched peers and reported similar frequencies of walking or biking. However, PPI users were less likely to have participated in muscle-strengthening activities (OR: 0.53; 95% CI: 0.30–0.95. PPI users reported similar sedentary behaviors to non-users. Male PPI users had an increase in weight (of 1.52 ± 0.59 kg; p = 0.021 over the previous year compared to non-users, while female PPI users had a non-significant increase in weight. The potential mechanisms for PPI-associated weight gain are unclear as we did not find evidence for significant differences in energy intake or markers of energy expenditure.

  15. Effect of esomeprazole, a proton pump inhibitor on the pharmacokinetics of sonidegib in healthy volunteers.

    Science.gov (United States)

    Zhou, Jocelyn; Quinlan, Michelle; Glenn, Kelli; Boss, Hildegard; Picard, Franck; Castro, Henry; Sellami, Dalila

    2016-10-01

    This study aimed to evaluate the impact of esomeprazole on the pharmacokinetics of sonidegib. This Phase I study evaluated the impact of the proton pump inhibitor (PPI) esomeprazole on the oral absorption and pharmacokinetics (PKs) of a single dose of sonidegib under fasted conditions. A total of 42 healthy subjects were enrolled to receive either sonidegib alone (200 mg single dose) or sonidegib in combination with esomeprazole (40 mg pre-treatment 5 days and combination were given on day 6). Primary PK parameters assessed in the study were area under the concentration-time curve (AUC) from 0-14 days and 0-7 days and maximum observed plasma concentration (Cmax ). The plasma exposure (AUC0-14d, AUC0-7d and Cmax ) of a single 200 mg oral dose of sonidegib was decreased by 32-38% when sonidegib was co-administered with esomeprazole compared with sonidegib alone, with no apparent change in elimination slope and tmax . Baseline gastric pH was similar between the two arms. These results suggest a modest reduction in the extent of sonidegib absorption by esomeprazole. There was no obvious metabolic drug-drug interaction between the two agents. Both sonidegib and esomeprazole were well tolerated in the study population. © 2016 The British Pharmacological Society.

  16. Comparison of vonoprazan and proton pump inhibitors for eradication of Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    Satoshi Shinozaki

    2016-05-01

    Full Text Available Alternative eradication therapies for Helicobacter pylori infection are needed because of an increasing failure rate over the past decade. The aim of this study was to determine if vonoprazan, a new potassium-competitive acid blocker, showed superiority to existing proton pump inhibitors for primary eradication of H. pylori in routine clinical practice. Data for 573 patients who underwent primary H. pylori eradication therapy were retrospectively reviewed. Regimens included clarithromycin 200 mg, amoxicillin 750 mg, and an acid-suppressing drug [lansoprazole 30 mg (LAC, rabeprazole 10 mg (RAC, esomeprazole 20 mg (EAC, or vonoprazan 20 mg (VAC] twice daily for 1 week. Eradication was successful in 73% (419/573 of patients using intention-to-treat (ITT analysis and 76% (419/549 of patients in per-protocol (PP analysis. The VAC group had a significantly superior eradication rate compared with the LAC and RAC groups in ITT (VAC 83%, LAC 66% and RAC 67%, p  80% eradication rate regardless of the degree of atrophy.

  17. Hyperparathyroidism Associated with Long-Term Proton Pump Inhibitors Independent of Concurrent Bisphosphonate Therapy in Elderly Adults.

    Science.gov (United States)

    Hinson, Andrew M; Wilkerson, Bekka M; Rothman-Fitts, Ivy; Riggs, Ann T; Stack, Brendan C; Bodenner, Donald L

    2015-10-01

    To measure the effect of proton pump inhibitors (PPIs), with and without concurrent bisphosphonates, on parathyroid hormone (PTH), vitamin D, and calcium. Retrospective chart review of individuals 60 years and older. Subjects with reduced renal function (creatinine >1.3 mg/dL) and low vitamin D (hyperparathyroidism regardless of concurrent oral BP administration. © 2015, Copyright the Authors Journal compilation © 2015, The American Geriatrics Society.

  18. Suspicion of Drug-Drug Interaction between High-Dose Methotrexate and Proton Pump Inhibitors: A Case Report - Should the Practice Be Changed?

    National Research Council Canada - National Science Library

    Ranchon, F; Vantard, N; Gouraud, A; Schwiertz, V; Franchon, E; Pham, B.N; Vial, T; You, B; Bouafia, F; Salles, G; Rioufol, C

    2011-01-01

    .... Alkaline hyperhydration, folinic acid and carboxypeptidase G2 were given. Prescription analyses by pharmacists and literature research have permitted us to suggest that a drug-drug interaction between methotrexate and proton pump inhibitors (PPI...

  19. Engineering a Chemical Switch into the Light-driven Proton Pump Proteorhodopsin by Cysteine Mutagenesis and Thiol Modification.

    Science.gov (United States)

    Harder, Daniel; Hirschi, Stephan; Ucurum, Zöhre; Goers, Roland; Meier, Wolfgang; Müller, Daniel J; Fotiadis, Dimitrios

    2016-07-25

    For applications in synthetic biology, for example, the bottom-up assembly of biomolecular nanofactories, modules of specific and controllable functionalities are essential. Of fundamental importance in such systems are energizing modules, which are able to establish an electrochemical gradient across a vesicular membrane as an energy source for powering other modules. Light-driven proton pumps like proteorhodopsin (PR) are excellent candidates for efficient energy conversion. We have extended the versatility of PR by implementing an on/off switch based on reversible chemical modification of a site-specifically introduced cysteine residue. The position of this cysteine residue in PR was identified by structure-based cysteine mutagenesis combined with a proton-pumping assay using E. coli cells overexpressing PR and PR proteoliposomes. The identified PR mutant represents the first light-driven proton pump that can be chemically switched on/off depending on the requirements of the molecular system. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Proton pump inhibitor use is associated with an increased risk for microscopic colitis: a case-control study.

    Science.gov (United States)

    Keszthelyi, D; Jansen, S V; Schouten, G A; de Kort, S; Scholtes, B; Engels, L G J B; Masclee, A A M

    2010-11-01

    Microscopic colitis causes chronic watery diarrhoea. Recent studies have suggested an aetiological role for various medications, including proton pump inhibitors, in the pathogenesis of microscopic colitis. To determine whether an association exists between microscopic colitis and proton pump inhibitor use in patients with documented microscopic colitis vs. age- and gender-matched controls. In this retrospective case-control study, cases of microscopic colitis from a secondary and tertiary referral medical centre diagnosed in the last 5 years were reviewed. Demographic characteristics, clinical, histological and endoscopic records, as well as exposure to PPIs and NSAIDs were assessed. Controls from the population were matched to cases by gender and by age. During the investigated period, 136 cases were identified in both hospitals. Of these, 95 cases of microscopic colitis were retrieved for detailed analysis. Exposure to proton pump inhibitors at the time of the histological diagnosis was significantly higher in patients with collagenous colitis than in controls [38% vs. 13%, P microscopic colitis and PPI use, and it supports the possible aetiological role of PPI exposure in the development of microscopic colitis. © 2010 Blackwell Publishing Ltd.

  1. In vivo effect of proton-pump inhibitors on gastric plasmin-dependent fibrinolysis: a study in a porcine model.

    Science.gov (United States)

    Thibault, Aurelie; Marteau, Philippe; Drouet, Ludovic; Lavergne Slove, Anne; Bal dit Sollier, Claire; Camus, Marine; Dray, Xavier

    2012-12-01

    Alkalization of gastric fluids could inhibit plasmin-mediated and/or pepsin-mediated fibrinolysis. We evaluated the gastric antifibrinolytic effect of proton pump inhibitors in a live porcine model. Six pigs were randomly assigned to treatment with proton pump inhibitors vs no treatment. After endoscopic mucosal resection, 8 μm sections were incubated on fibrin films. Fibrinolytic activity was assessed through focal lysis time. One-hundred-and-forty-two mucosal sections and 129 submucosal sections were analysed. Twenty-four additional sections were analysed on plates containing tranexamic acid to explore pepsin-mediated fibrinolysis. Focal lysis times in treated vs control groups were 21.0 min vs 21.2 min (p = 0.39) in the mucosa, and 22.2 min vs 20.2 min (p = 0.56) in the submucosa. No lysis could be seen on the plasmin-inhibited fibrin plates. Only plasmin-mediated fibrinolysis was observed. Proton pump inhibitors had no significant plasmin-dependant antifibrinolytic effect. They may enhance haemostasis through different pathways. Copyright © 2012 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  2. Factors affecting Helicobacter pylori eradication using a seven-day triple therapy with a proton pump inhibitor, tinidazole and clarithromycin, in brazilian patients with peptic ulcer

    OpenAIRE

    Silva, Fernando Marcuz; Zaterka,Schlioma; Eisig, Jaime Natan; Chehter,Ethel Zimberg; CHINZON,Décio; Laudanna, Antonio Atílio

    2001-01-01

    Triple therapy is accepted as the treatment of choice for H. pylori eradication. In industrialized countries, a proton pump inhibitor plus clarithromycin and amoxicillin or nitroimidazole have shown the best results. Our aims were: 1. To study the eradication rate of the association of a proton pump inhibitor plus tinidazole and clarithromycin on H. pylori infection in our population. 2. To determine if previous treatments, gender, age, tobacco, alcohol use, and non-steroidal anti-inflammator...

  3. Murine ameloblasts are immunonegative for Tcirg1, the v-H-ATPase subunit essential for the osteoclast plasma proton pump.

    Science.gov (United States)

    Bronckers, Antonius L J J; Lyaruu, Donacian M; Bervoets, Theodore J; Medina, Juan F; DenBesten, Pamela; Richter, Johan; Everts, Vincent

    2012-04-01

    Maturation stage ameloblasts of rodents express vacuolar type-H-ATPase in the ruffled border of their plasma membrane in contact with forming dental enamel, similar to osteoclasts that resorb bone. It has been proposed that in ameloblasts this v-H-ATPase acts as proton pump to acidify the enamel space, required to complete enamel mineralization. To examine whether this v-H-ATPase in mouse ameloblasts is a proton pump, we determined whether these cells express the lysosomal, T-cell, immune regulator 1 (Tcirg1, v-H-Atp6v(0)a(3)), which is an essential part of the plasma membrane proton pump that is present in osteoclasts. Mutation of this subunit in Tcirg1 null (or oc/oc) mice leads to severe osteopetrosis. No immunohistochemically detectable Tcirg1 was seen in mouse maturation stage ameloblasts. Strong positive staining in secretory and maturation stage ameloblasts however was found for another subunit of v-H-ATPase, subunit b, brain isoform (v-H-Atp6v(1)b(2)). Mouse osteoclasts and renal tubular epithelium stained strongly for both Tcirg1 and v-H-Atp6v(1)b(2). In Tcirg1 null mice osteoclasts and renal epithelium were negative for Tcirg1 but remained positive for v-H-Atp6v(1)b(2). The bone in these mutant mice was osteopetrotic, tooth eruption was inhibited or delayed, and teeth were often morphologically disfigured. However, enamel formation in these mutant mice was normal, ameloblasts structurally unaffected and the mineral content of enamel similar to that of wild type mice. We concluded that Tcirg1, which is essential for osteoclasts to pump protons into the bone, is not appreciably expressed in maturation stage mouse ameloblasts. Our data suggest that the reported v-H-ATPase in maturation stage ameloblasts is not the typical osteoclast-type plasma membrane associated proton pump which acidifies the extracellular space, but rather a v-H-ATPase potentially involved in intracellular acidification. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Proton pump inhibitors inhibit metformin uptake by organic cation transporters (OCTs.

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    Anne T Nies

    Full Text Available Metformin, an oral insulin-sensitizing drug, is actively transported into cells by organic cation transporters (OCT 1, 2, and 3 (encoded by SLC22A1, SLC22A2, or SLC22A3, which are tissue specifically expressed at significant levels in various organs such as liver, muscle, and kidney. Because metformin does not undergo hepatic metabolism, drug-drug interaction by inhibition of OCT transporters may be important. So far, comprehensive data on the interaction of proton pump inhibitors (PPIs with OCTs are missing although PPIs are frequently used in metformin-treated patients. Using in silico modeling and computational analyses, we derived pharmacophore models indicating that PPIs (i.e. omeprazole, pantoprazole, lansoprazole, rabeprazole, and tenatoprazole are potent OCT inhibitors. We then established stably transfected cell lines expressing the human uptake transporters OCT1, OCT2, or OCT3 and tested whether these PPIs inhibit OCT-mediated metformin uptake in vitro. All tested PPIs significantly inhibited metformin uptake by OCT1, OCT2, and OCT3 in a concentration-dependent manner. Half-maximal inhibitory concentration values (IC(50 were in the low micromolar range (3-36 µM and thereby in the range of IC(50 values of other potent OCT drug inhibitors. Finally, we tested whether the PPIs are also transported by OCTs, but did not identify PPIs as OCT substrates. In conclusion, PPIs are potent inhibitors of the OCT-mediated metformin transport in vitro. Further studies are needed to elucidate the clinical relevance of this drug-drug interaction with potential consequences on metformin disposition and/or efficacy.

  5. Investigation of proton pump inhibitors binding with bovine serum albumin and their relationship to molecular structure

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    Zhang Yuping [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Shi Shuyun, E-mail: shuyshi@gmail.com [School of Chemistry and Chemical Engineering, Central South University, Changsha 410083 (China); Peng Mijun, E-mail: pengmj163@163.com [Key Laboratory of Hunan Forest Products and Chemical Industry Engineering, Jishou University, Zhangjiajie 427000 (China)

    2012-08-15

    The interactions of three proton pump inhibitors (PPIs), omeprazole, pantoprazole and ilaprazole with bovine serum albumin (BSA) have been investigated by fluorescence, synchronous fluorescence, ultraviolet-visible (UV-vis) and circular dichroism (CD). Various binding parameters have been calculated at various temperatures. The results indicated that omeprazole, pantoprazole and ilaprazole had a strong ability to quench the intrinsic fluorescence of BSA with static quenching mechanism, and the binding affinities were significantly affected by different substituents and polarities as the order ilaprazole>pantoprazole>omeprazole. The site marker competitive experiments indicated that the binding of omeprazole, pantoprazole and ilaprazole to BSA primarily took place in subdomain IIA. The results of thermodynamic parameters {Delta}G, {Delta}H and {Delta}S indicated that electrostatic interaction played a major role for PPIs-BSA association. The distance r between PPIs and BSA was evaluated according to the theory of Foerster's energy transfer. The quantitative analysis of synchronous fluorescence and CD spectra showed the change in secondary structure of the BSA upon interaction with PPIs by a reduction of {alpha}-helix. All the above results many have relevant insight into the PPIs' availability and distribution. - Highlights: Black-Right-Pointing-Pointer The interactions of three PPIs with BSA have been investigated. Black-Right-Pointing-Pointer The fluorescence quenching mechanism is static quenching. Black-Right-Pointing-Pointer Binding affinities were greatly affected by the substituents and polarities. Black-Right-Pointing-Pointer The binding of three PPIs to BSA primarily took place in subdomain IIA.

  6. Single enantiomer versus racemate: chiral distinction in the proton pump inhibitors omeprazole and esomeprazole.

    Science.gov (United States)

    Marom, Hili; Pogodin, Sergey; Agranat, Israel

    2014-04-01

    Chiral distinction in the proton pump inhibitor drugs omeprazole and in its chiral-switch esomeprazole magnesium was studied employing the Density Functional Theory (DFT) method. At B3LYP/6-311G(d,p), the 6-methoxy∙∙∙6-methoxy and 5-methoxy∙∙∙5-methoxy homochiral and heterochiral dimers were calculated. The chiral distinction free energies (ΔΔG(298,(RS-SS))) between the cyclic C2-(S,S)- and Ci-(R,S)-dimers with two intermolecular hydrogen bonds are 3.8, 1.9 (with BSSE counterpoise correction), and -6.9 (with D3 dispersion and BSSE counterpoise corrections) kJ/mol. Adding water as an implicit solvent (polarized continuum model [PCM] model) resulted in a chiral distinction energy of -3.3 kJ/mol, indicating a reversal of the order of the relative stabilities of C2-(S,S)- and Ci-(R,S)-dimers. The chiral distinction free energies between the corresponding (less stable) C1-dimers with one intermolecular hydrogen bond are -9.3, -5.8 (with BSSE CC), 17.6 (D3 + BSSE CC), and -3.2 (H2O) kJ/mol. The results highlight the contention that omeprazole is not just a superposition of its enantiomer constituents. They are consistent with the pharmacological evidence of enantiomer-enantiomer interactions in omeprazole versus esomeprazole and the differences between the drugs omeprazole and esomeprazole magnesium and support the lodged application for regulatory supplementary protection certificate (SPC) exclusivity for the esomeprazole-related combination drug Vimovo. Copyright © 2014 Wiley Periodicals, Inc.

  7. Proton Pump Inhibitor and Histamine-2 Receptor Antagonist Use and Iron Deficiency.

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    Lam, Jameson R; Schneider, Jennifer L; Quesenberry, Charles P; Corley, Douglas A

    2017-03-01

    Proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) suppress gastric acid production, which can inhibit iron absorption. However, few data exist regarding whether these medications increase the risk of clinical iron deficiency. A community-based case-control study evaluated the association between acid-suppressing medication use and the subsequent risk of iron deficiency. It contrasted 77,046 patients with new iron deficiency diagnoses (January 1999-December 2013), with 389,314 controls. Medication exposures, outcomes, and potential confounders used electronic databases. We excluded patients with pre-existing risk factors for iron deficiency. Associations were estimated using conditional logistic regression. Among cases, 2343 (3.0%) received a prior ≥2-year supply of PPIs and 1063 (1.4%) received H2RAs (without PPI use). Among controls, 3354 (0.9%) received a prior ≥2-year supply of PPIs and 2247 (0.6%) H2RAs. Both ≥2 years of PPIs (adjusted odds ratio, 2.49; 95% confidence interval, 2.35-2.64) and ≥2 years of H2RAs (odds ratio, 1.58; 95% CI, 1.46-1.71) were associated with an increased subsequent risk for iron deficiency. Among PPI users, the associations were stronger for higher daily doses (>1.5 vs 1.5 pills per day for at least 10 years (odds ratio, 4.27; 95% CI, 2.53-7.21). No similar strong associations were found for other commonly used prescription medications. Among patients without known risk factors for iron deficiency, gastric acid inhibitor use for ≥2 years was associated with an increased subsequent risk of iron deficiency. The risk increased with increasing potency of acid inhibition and decreased after medication discontinuation. Copyright © 2017 AGA Institute. Published by Elsevier Inc. All rights reserved.

  8. Optimal management of antiplatelet therapy and proton pump inhibition following percutaneous coronary intervention.

    Science.gov (United States)

    Thomas, Mark R; Storey, Robert F

    2012-02-01

    Dual antiplatelet therapy (aspirin and a P2Y(12) antagonist) is required after the insertion of a coronary artery stent. If the stent has been inserted in the context of an acute coronary syndrome (ACS), then clopidogrel or a high-potency P2Y(12) antagonist such as prasugrel or ticagrelor should be considered. Current indications for the use of prasugrel in this situation include ST elevation, diabetes, or previous stent thrombosis on clopidogrel therapy. If the stent has been inserted electively for stable ischemic heart disease, then the patient should normally receive clopidogrel. Next, it is important to consider the patient's bleeding risk. The CRUSADE score can be used to determine the likelihood of a subsequent gastrointestinal (GI) bleed. For patients treated with aspirin and clopidogrel who are at high risk of a GI bleed, the current evidence suggests that a proton pump inhibitor (PPI) is the most effective way to reduce this risk. There is evidence that omeprazole may attenuate the pharmacodynamic effect of clopidogrel and, therefore, it would be reasonable to use an alternative PPI that has less risk of negative pharmacokinetic and pharmacodynamic interaction, such as pantoprazole. If a patient is at moderate or low risk of bleeding, then a PPI should be avoided in combination with clopidogrel as the risk of negative interaction is greater than the risk of GI bleeding. There is no substantive evidence that PPIs attenuate the therapeutic effect of prasugrel or ticagrelor; therefore, patients at moderate or high risk of GI bleeding should be offered a PPI.

  9. Influence of proton pump inhibitors on gastritis diagnosis and pathologic gastric changes.

    Science.gov (United States)

    Nasser, Soumana C; Slim, Mahmoud; Nassif, Jeanette G; Nasser, Selim M

    2015-04-21

    To investigate the influence of proton pump inhibitors (PPIs) exposure on the diagnosis of Helicobacter pylori (H. pylori) gastritis and intestinal metaplasia. Chronic PPI use is associated with masking of H. pylori infection. Patients with H. pylori infection are predisposed to gastric and duodenal ulcers, and long-term infection with this organism has been associated with gastric mucosal atrophy and serious long-term complications, such as gastric lymphoma and adenocarcinoma. Three hundred patients diagnosed with gastritis between January 2008 and April 2010 were included in our study. The computerized medical database of these patients was reviewed retrospectively in order to assess whether the type of gastritis diagnosed (H. pylori vs non-H. pylori gastritis) is influenced by PPI exposure. H. pylori density was graded as low, if corresponding to mild density following the Updated Sydney System, or high, if corresponding to moderate or severe densities in the Updated Sydney System. Patients were equally distributed between males and females with a median age at the time of diagnosis of 50 years old (range: 20-87). The histological types of gastritis were classified as H. pylori gastritis (n = 156, 52%) and non-H. pylori gastritis (n = 144, 48%). All patients with non-H. pylori gastritis had inactive chronic gastritis. Patients with no previous PPI exposure were more likely to be diagnosed with H. pylori gastritis than those with previous PPI exposure (71% vs 34.2%, P gastritis and leads to a significant drop in H. pylori densities and to an increased risk of intestinal metaplasia. The use of PPIs masks H. pylori infection, promotes the diagnosis of non-H. pylori inactive chronic gastritis diagnosis, and increases the incidence of intestinal metaplasia.

  10. EFFECTS OF PROTON PUMP INHIBITORS ON DENTAL EROSIONS CAUSED BY GASTROESOPHAGEAL REFLUX DISEASE

    Directory of Open Access Journals (Sweden)

    Andrei Vasile OLTEANU

    2015-12-01

    Full Text Available Background: Numerous studies worldwide have assessed the association between dental erosions or other related oral manifestations, and the gastroesophageal reflux disease (GERD. Nowadays, one of the main therapeutic resources of GERD is represented by proton pump inhibitors (PPIs. Adequate salivary secretions and flow are considered mandatory for the protection of both teeth and esophageal mucosa. The aim of the present study was to evaluate the possible correlation between GERD treatment options and subsequent control of oral manifestation, taking as premises that either PPIs or dietary and lifestyle changes may control oral patterns of GERD by acting on salivary secretions. Methods: 48 clinically diagnosed GERD adult patients with oral manifestations, mainly erosions, were included in the study, none of which showing alarming symptoms that would require further gastroenterologic examination. Oral examination evaluated the DMF (decayed, missing, filled and OHI-S (Simplified Oral Hygiene indices. Salivary flow was evaluated by the Saxon test. 25 patients were prescribed dietary and lifestyle measures and PPIs (omeprazole – 20 mg, whereas 23 patients were managed only through dietary and lifestyle modifications. General assessment was performed at the time of diagnosis and 4 weeks afterwards. Results: No significant differences as to the DMF index, OHI-S index or Saxon test were found over the 4 weeks management between the groups. Conclusions: Oral manifestation of GERD may be caused by impaired salivary secretions and flow, otherwise no - positive or negative - effect could be secondary to PPI therapy. Accordingly, complex oral rehabilitation of GERD patients and collaboration between gastroenterologists and dentists should be promoted.

  11. Association between use of proton pump inhibitors and occurrence of colon diverticulitis.

    Science.gov (United States)

    Ho, Bo-Lung; Hu, Hsiao-Yun; Chang, Shen-Shong

    2016-01-01

    Some recent studies have described the adverse effects of proton pump inhibitors (PPIs). PPI use and colonic diverticulitis are both associated with bacterial enteric infection and translocation. The aim of this study was to assess the association between PPI use and colonic diverticulitis. We conducted a population-based nested case-control study in part by use of data retrospectively collected from the National Health Insurance Research Database. Diverticulitis patients were identified using inpatient discharge records with International Classification of Diseases, Ninth Revision, Clinical Modification codes (562.11 and 562.13), and were recruited as the study cohort. The controls were matched to the study patients by age, sex, nonsteroidal anti-inflammatory drugs use, laxative use, and index date. The cumulative defined daily dose (DDD) was estimated as the sum of the dispensed DDD of any PPI. The adjusted odds ratio and 95% confidence interval (CI) were estimated using multiple logistic regression. We enrolled 690 patients with acute diverticulitis, along with 2760 patients who comprised the control group. The adjusted odds ratios for the study cohort compared with PPI nonusers, after adjusting for possible confounders (including sex, age, comorbidities, and medication), were 1.29 (95% CI = 0.70-2.36) and 1.02 (95% CI = 0.59-1.76) for the group with cumulative PPI use ≥42 and ≥55 DDDs over an exposure period of 90 and 180 days, respectively, prior to the claimed date of hospitalization for colonic diverticulitis. The study showed that use of PPIs did not increase the risk of colon diverticulitis. Copyright © 2015. Published by Elsevier Taiwan LLC.

  12. Association of Proton Pump Inhibitors Usage with Risk of Pneumonia in Dementia Patients.

    Science.gov (United States)

    Ho, Sai-Wai; Teng, Ying-Hock; Yang, Shun-Fa; Yeh, Han-Wei; Wang, Yu-Hsun; Chou, Ming-Chih; Yeh, Chao-Bin

    2017-07-01

    To determine the association between usages of proton pump inhibitors (PPIs) and subsequent risk of pneumonia in dementia patients. Retrospective cohort study. Taiwanese National Health Insurance Research Database. The study cohort consisted of 786 dementia patients with new PPI usage and 786 matched dementia patients without PPI usage. The study endpoint was defined as the occurrence of pneumonia. The Cox proportional hazard model was used to estimate the pneumonia risk. Defined daily dose methodology was applied to evaluate the cumulative and dose-response relationships of PPI. Incidence of pneumonia was higher among patients with PPI usage (adjusted hazard ratio (HR) = 1.89; 95% CI = 1.51-2.37). Cox model analysis also demonstrated that age (adjusted HR = 1.05; 95% CI = 1.03-1.06), male gender (adjusted HR = 1.57; 95% CI = 1.25-1.98), underlying cerebrovascular disease (adjusted HR = 1.30; 95% CI = 1.04-1.62), chronic pulmonary disease (adjusted HR = 1.39; 95% CI = 1.09-1.76), congestive heart failure (adjusted HR = 1.54; 95% CI = 1.11-2.13), diabetes mellitus (adjusted HR = 1.54; 95% CI = 1.22-1.95), and usage of antipsychotics (adjusted HR = 1.29; 95% CI = 1.03-1.61) were independent risk factors for pneumonia. However, usage of cholinesterase inhibitors and histamine receptor-2 antagonists were shown to decrease pneumonia risk. PPI usage in dementia patients is associated with an 89% increased risk of pneumonia. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

  13. Proton Pump Inhibitors and Survival Outcomes in Patients With Metastatic Renal Cell Carcinoma.

    Science.gov (United States)

    Lalani, Aly-Khan A; McKay, Rana R; Lin, Xun; Simantov, Ronit; Kaymakcalan, Marina D; Choueiri, Toni K

    2017-12-01

    Proton pump inhibitors (PPIs) are potent inhibitors of gastric acid secretion and can affect the optimal absorption of concomitant oral medications, such as vascular endothelial growth factor (VEGF) tyrosine kinase inhibitors (TKIs). The purpose of this study was to investigate the effect of PPI use on survival in metastatic renal cell carcinoma (mRCC) patients treated in the targeted therapy era. We conducted a pooled analysis of mRCC patients treated in phase II and III clinical trials. Statistical analyses were performed using Cox regression adjusted for several risk factors and the Kaplan-Meier method. We identified 2188 patients treated with sunitinib (n = 952), axitinib (n = 626) or sorafenib (n = 610), of whom 120 were PPI users. Overall, PPI users showed similar overall survival compared with non-PPI users (hazard ratio [HR], 1.051; 95% confidence interval [CI], 0.769-1.438; P = .754; median, 24.1 vs. 21.3 months). Similarly, progression-free survival (HR, 1.016; 95% CI, 0.793-1.301; P = .902; median, 5.5 vs. 8.0 months) and objective response rates (23.3% vs. 27.4%; P = .344) were not different between PPI users and nonusers. These findings were consistent across International mRCC Database Consortium risk groups and according to line of therapy. Adverse events were similar between PPI users and nonusers. We showed that PPI use does not appear to negatively affect the efficacy and safety of select VEGF-TKIs in patients with mRCC. Documentation of concomitant medications and patient education on potential drug interactions are critical for optimizing the use of oral cancer-targeting therapy. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Effect of Long-Term Proton Pump Inhibitor Therapy on Nutritional Status in Elderly Hospitalized Patients.

    Science.gov (United States)

    Nakamichi, Mariko; Wakabayashi, Hidetaka

    2016-01-01

    The purpose was to investigate the association between proton pump inhibitor (PPI) therapy and nutritional status in elderly hospitalized patients. Participants were 190 elderly patients admitted to the long-term care wards, convalescence rehabilitation wards, and community integrated care wards in January 2015. Nutritional status was assessed using the mini nutritional assessment short-form (MNA-SF). The PPI use group was compared with the PPI non-use group regarding nutrition status. Logistic regression analysis was used to examine whether the period of PPI therapy was associated independently with malnutrition following adjustment for covariates including gender, age, and serum albumin level. Forty-one patients were male (22%) and 149 patients were female (78%), with a mean age of 85.4±8.4. Fifty-three patients (28%) took PPIs (with a median prescription period of 91 d, ranging from 51 to 227). With a MNA-SF score of 7 points or lower designated as malnutrition, there was no significant difference in nutritional status between the PPI and non-PPI groups (p=0.172). The median MNA-SF scores in the PPI and non-PPI groups were 9 vs 7 points, respectively. Logistic regression analysis showed that long-term PPI therapy (odds ratio, 0.994; 95% confidence interval 0.990-0.999) was significantly associated with improved nutritional status. The presence or absence of PPI therapy is not associated with malnutrition in elderly hospitalized patients. Longer-term PPI therapy may improve nutritional status.

  15. The safety of proton pump inhibitors (PPIs) in pregnancy: a meta-analysis.

    Science.gov (United States)

    Gill, Simerpal K; O'Brien, Lisa; Einarson, Thomas R; Koren, Gideon

    2009-06-01

    Heartburn and acid reflux are common medical disorders in pregnancy and can result in serious discomfort and complications. Furthermore, some pregnant women also experience more severe gastrointestinal conditions, such as Helicobacter pylori infections, peptic ulcers, and Zollinger-Ellison syndrome. To allow the use of proton pump inhibitors (PPIs) in pregnancy, the fetal safety of this drug class must be established. The aim of this study is to determine the fetal safety of PPIs during early pregnancy through systematic literature review. All original research assessing the safety of PPIs in pregnancy was sought from inception to July 2008. Two independent reviewers identified articles, compared results, and settled differences through consensus. The Downs-Black scale was used to assess quality. Data assessed included congenital malformations, spontaneous abortions, and preterm delivery. A random effects meta-analysis combined the results from included studies. Of the 60 articles identified, 7 met our inclusion criteria. Using data from 134,940 patients, including 1,530 exposed and 133,410 not exposed to PPIs, the overall odds ratio (OR) for major malformations was 1.12 (95% confidence interval, CI: 0.86-1.45). Further analysis revealed no increased risk for spontaneous abortions (OR=1.29, 95% CI: 0.84-1.97); similarly, there was no increased risk for preterm delivery (OR=1.13, 95% CI: 0.96-1.33). In the secondary analysis of 1,341 exposed and 120,137 not exposed to omeprazole alone, the OR and 95% CI for major malformations were 1.17 and 0.90-1.53, respectively. On the basis of these results, PPIs are not associated with an increased risk for major congenital birth defects, spontaneous abortions, or preterm delivery. The narrow range of 95% CIs is further reassuring, suggesting that PPIs can be safely used in pregnancy.

  16. [Analysis of the use of proton pump inhibitors in primary health care].

    Science.gov (United States)

    Hernández-Arroyo, M J; Díaz-Madero, A; Enríquez-Gutiérrez, E; Teijeiro-Bermejo, M C; Sáez-Rodríguez, E; Gutiérrez-Martín, M R

    2017-11-15

    The increase in the consumption of anti-ulcer drugs is accompanied by a high rate of incorrect use. The objectives of this study were to analyse the adequacy of repeat prescriptions of proton pump inhibitors (PPIs) in a Medical Centre, and to evaluate the efficacy of an improvement intervention. A cross-sectional, descriptive and observational study of prevalence was conducted on patients in a medical centre under treatment with PPIs for at least 3consecutive months (November 2016-January 2017). An analysis was performed that included the indication, dosage and time of treatment with PPIs, drug interactions, and possible risks that could be related with their use. An intervention was carried out to optimise rational and efficient prescribing of these medicines. A total of 703 patients were included in the study, which is 5.4% of the total adult patients that are assigned to the centre. Adequacy criteria were not met by 436 (62.0%). Of these, 52.5% were women, 70.0% were over 65 years old, and had been on treatment for a mean of 2.7 ± 1.9 years. Interactions were observed in 48.1%, and 29.0% had some risk factors. After the intervention, the inadequate prescribing was corrected in 112 (25.7%) patients, which was a reduction of 46.1% (P<.001). There is a high prevalence of prescription and inadequacy of PPIs in the long term. This suggests that it is necessary to improve training of professionals to strengthen rational use and to reduce risks. The launch of an intervention programme has led to the revision and optimisation of treatments. Copyright © 2017 Sociedad Española de Médicos de Atención Primaria (SEMERGEN). Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Intake of Proton Pump Inhibitors Is Associated with an Increased Risk of Dental Implant Failure.

    Science.gov (United States)

    Chrcanovic, Bruno Ramos; Kisch, Jenö; Albrektsson, Tomas; Wennerberg, Ann

    To investigate the association between the intake of proton pump inhibitors (PPIs) and the risk of dental implant failure. The present retrospective cohort study is based on patients consecutively treated between 1980 and 2014 with implant-supported/retained prostheses at one specialist clinic. Modern endosseous dental implants with cylindrical or conical design were included, and only complete cases were considered; ie, only those implants with information available for all variables measured were included in the regression model analysis. Zygomatic implants and implants detected in radiographies but without basic information about them in the patients' files were excluded from the study. Implant- and patient-related data were collected. Multilevel mixed-effects parametric survival analysis was used to test the association between PPI exposure (predictor variable) and risk of implant failure (outcome variable), adjusting for several potential confounders. A total of 3,559 implants were placed in 999 patients, with 178 implants reported as failures. The implant failure rates were 12.0% (30/250) for PPI users and 4.5% (148/3,309) for nonusers. A total of 45 out of 178 (25.3%) failed implants were lost up to abutment connection (6 in PPI users, 39 in nonusers), with an early-to-late failure ratio of 0.34:1. The intake of PPIs was shown to have a statistically significant negative effect for implant survival rate (HR 2.811; 95% CI: 1.139 to 6.937; P = .025). Bruxism, smoking, implant length, prophylactic antibiotic regimen, and implant location were also identified as factors with a statistically significant effect on the implant survival rate. This study suggests that the intake of PPIs may be associated with an increased risk of dental implant failure.

  18. Mass balance and metabolism of Z-215, a novel proton pump inhibitor, in healthy volunteers.

    Science.gov (United States)

    Toda, Ryoko; Miyagawa, Tomoharu; Masuda, Yuka; Hoshino, Yusuke; Yoshii, Kazuyoshi; Hirayama, Masamichi; Shibuya, Minaka; Kawabata, Yoshihiro

    2017-11-02

    The human mass balance of [(14 )C]Z-215, a novel proton pump inhibitor, was characterised in six healthy male volunteers following single oral administration of [(14 )C]Z-215 (20 mg, 3.7 MBq) to determine the elimination pathway of Z-215 and the distribution of its metabolites in plasma, urine, and faeces (NCT02618629). [(14 )C]Z-215 was rapidly absorbed, with a Cmax of 434 ng/mL at 0.38 h for Z-215 and 732 ng eq./mL at 0.5 h for total radioactivity. Means of 59.61% and 31.36% of the administered radioactive dose were excreted in urine and faeces, respectively, within 168 h post-dose. The majority of the dose was recovered within 24 h in urine and 96 h in faeces. Unchanged Z-215 was excreted in urine at trace levels but was not detected in faeces. The main components in plasma were Z-215 and Z-215 sulphone, accounting for 29.8% and 13.3% of the total circulating radioactivity, respectively. Additionally, Z-215 was metabolised through oxidation, reduction and conjugation. Our in vitro Z-215 metabolism study showed that the major isozyme contributing to the oxidation of Z-215, including the formation of Z-215 sulphone, was CYP3A4. In conclusion, Z-215 is well absorbed in humans and primarily eliminated via metabolism, where CYP3A4 plays an important role.

  19. The proton pump inhibitor lansoprazole improves the skeletal phenotype in dystrophin deficient mdx mice.

    Directory of Open Access Journals (Sweden)

    Arpana Sali

    Full Text Available In Duchenne muscular dystrophy (DMD, loss of the membrane stabilizing protein dystrophin results in myofiber damage. Microinjury to dystrophic myofibers also causes secondary imbalances in sarcolemmic ion permeability and resting membrane potential, which modifies excitation-contraction coupling and increases proinflammatory/apoptotic signaling cascades. Although glucocorticoids remain the standard of care for the treatment of DMD, there is a need to investigate the efficacy of other pharmacological agents targeting the involvement of imbalances in ion flux on dystrophic pathology.We designed a preclinical trial to investigate the effects of lansoprazole (LANZO administration, a proton pump inhibitor, on the dystrophic muscle phenotype in dystrophin deficient (mdx mice. Eight to ten week-old female mice were assigned to one of four treatment groups (n = 12 per group: (1 vehicle control; (2 5 mg/kg/day LANZO; (3 5 mg/kg/day prednisolone; and (4 combined treatment of 5 mg/kg/day prednisolone (PRED and 5 mg/kg/day LANZO. Treatment was administered orally 5 d/wk for 3 months. At the end of the study, behavioral (Digiscan and functional outcomes (grip strength and Rotarod were assessed prior to sacrifice. After sacrifice, body, tissue and organ masses, muscle histology, in vitro muscle force, and creatine kinase levels were measured. Mice in the combined treatment groups displayed significant reductions in the number of degenerating muscle fibers and number of inflammatory foci per muscle field relative to vehicle control. Additionally, mice in the combined treatment group displayed less of a decline in normalized forelimb and hindlimb grip strength and declines in in vitro EDL force after repeated eccentric contractions.Together our findings suggest that combined treatment of LANZO and prednisolone attenuates some components of dystrophic pathology in mdx mice. Our findings warrant future investigation of the clinical efficacy of LANZO and

  20. Impact of pharmacy intervention on the use of proton-pump inhibitors in the hospital setting.

    Science.gov (United States)

    Atkins, Richard; Smith, Lori

    2013-12-01

    Determine effectiveness of pharmacy-driven medical staff training regarding proton-pump inhibitor (PPI) therapy. This study was performed in two parts. Part I evaluated baseline PPI usage within the hospital. Part II evaluated the effect of pharmacy-driven medical staff education on PPI prescribing patterns. Data were collected retrospectively via electronic chart review. Passavant Area Hospital in Jacksonville, Illinois, is a 99-bed community hospital. Patients' profiles were selected if administration of at least one PPI was electronically charted during their hospital stay. Patients discharged from the emergency department were not included in the study. There were a total of 1,089 charts reviewed (Part I: N=565; Part II: N=524). The average patient age was 66.5 years. Part I results were presented to the pharmacy and therapeutics (P&T) committee and medical staff. A series of three educational presentations were subsequently given to medical staff. Part II results were reported to the P&T committee, with further interventions to be determined after consulting with hospital administration and medical staff. Improvement of appropriate acute PPI therapy. Secondary outcome measures included duration of acute therapy and continuation of chronic therapy. There was improvement in the appropriate usage of PPI for stress ulcer prophylaxis (SUP) (P=0.1216), decreased chronic PPI therapy (P=0.0054), and increased documentation of PPI indication (P=0.0365). A decrease of appropriate acute duration of PPI for SUP was also observed (PPharmacy interventions have an overall positive impact on appropriate use of PPI therapy.

  1. Proton-Pump Inhibitor Exposure Aggravates Clostridium difficile-Associated Colitis: Evidence From a Mouse Model.

    Science.gov (United States)

    Hung, Yuan-Pin; Ko, Wen-Chien; Chou, Po-Han; Chen, Yi-Hsuan; Lin, Hsiao-Ju; Liu, Ya-Hui; Tsai, Hung-Wen; Lee, Jen-Chieh; Tsai, Pei-Jane

    2015-08-15

    Clostridium difficile is currently the leading cause of infectious diarrhea in hospitalized patients. In addition to the infection due to toxigenic C. difficile in the gastrointestinal tract of susceptible hosts, other predisposing factors for C. difficile infection (CDI) are identified, including advanced age, a prolonged hospital stay, and use of acid-suppressive drugs. Of note, exposure to gastric acid-reducing agents, such as H2 blockers and proton pump inhibitors (PPIs), remains a controversial risk factor, and has been associated with CDI in some studies but not in others. A mouse model of antibiotic-associated clostridial colitis was established to examine the role of PPIs for CDI. A mouse model of antibiotic-associated clostridial colitis was set up. NF-κB reporter mice were used to address the in vivo spatial and temporal inflammatory patterns of C. difficile-associated colitis. Serum levels of lipopolysaccharide and dextran-FITC were measured to reflect the barrier permeability of affected intestines. Mice with CDI that were exposed to PPI exhibited greater losses of stool consistency and body and cecal weights than those that were not exposed to PPI. Further, more neutrophilic infiltrations, epithelial damage, and inflammatory cytokine expression were noted in colon specimens of the mice with PPI exposure. More-evident inflammatory responses were detected by in vivo imaging of NF-κB reporter mice with CDI that were exposed to PPI. Gut barrier permeability was increased to a greater extent, as reflected by higher serum levels of lipopolysaccharide and dextran-FITC in mice with CDI that were exposed to PPI. Our mouse model demonstrates that PPI exposure increases the severity of intestinal inflammation in mice with C. difficile-associated colitis. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  2. Proton pump inhibitor use in the U.S. ambulatory setting, 2002-2009.

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    Stephen R Rotman

    Full Text Available BACKGROUND AND AIMS: Anecdotal reports and studies of select populations suggest that the use of proton pump inhibitors (PPIs has increased since their introduction. We sought to determine recent trends in PPI use in the U.S. outpatient setting and characteristics of patients and physicians that may predict their use. METHODS: We used data from the National Ambulatory Medical Care Survey (NAMCS and the National Hospital Ambulatory Medical Care Survey (NHAMCS to estimate the prevalence of visits in which patients used PPIs from 2002 to 2009. We tested for associations between PPI use and patient, physician, and practice characteristics using data from 2009. We also estimated the prevalence of visits in which PPIs were used by patients without gastrointestinal complaints, diagnoses, or other indications for their use and tested for associations between patient and physician characteristics and PPI use in patients with no documented indication. RESULTS: PPIs were used in 4.0% of visits in 2002 and 9.2% in 2009 (p<0.001 for trend across years. The use of omeprazole (0.9% in 2002 to 3.9% in 2009, p<0.001, esomeprazole (0.9% in 2002 to 2.3% in 2009, p<0.001, and pantoprazole (0.6% in 2002 to 1.6% in 2009, p<0.001 increased significantly over the study period. Among visits by patients using PPIs, 62.9% documented no gastrointestinal complaints, gastrointestinal diagnoses, or other indicated reason for their use. CONCLUSIONS: We found that PPI use increased significantly from 2002 to 2009 as did documented indications for their use. Newly-prescribed PPI use did not change from 2006 to 2009. More research is needed to determine whether PPIs are overused in the U.S. outpatient setting.

  3. Influence of generics in prescribing dynamics of proton pump inhibitors in general practice

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    Simona Cammarota

    2009-01-01

    Full Text Available Use of antisecretory drugs has greatly increased in recent years in Italy. After the launching of generic lansoprazole (early 2006, several Italian Regional Health Authorities have introduced measures to favour the prescription of less expensive PPI. The aim of this study is to evaluate general practitioners’ prescription (GPs of different Proton Pump Inhibitors (PPIs in the period between 2005 to 2008. Analysis has been performed on a database of 99 medical practitioners that have managed an average of 150,000 inhabitants. We evaluate the PPIs prescriptions from Jan 2005 to Dec 2008. Evaluations performed are the following: 1 PPI prescription (total and separately for lansoprazole, esomeprazole, pantoprazole, rabeprazole, and omeprazole; 2 prevalence of the reimbursement purpose (Gastroprotection – G; Acid-Related Disease – ARD; 3 PPI prescriptions separately for ARD diagnostic codes. Data were expressed as Compound Annual Growth Rate (CAGR. PPI consumption were quantified using Defined Daily Dose system (DDD. The total volume of PPI’s prescribing increased progressively over the 4 years (CAGR +15%. The proportion of defined daily doses accounted for by lansoprazole increased from 12.0% in 2005 to 30.9% in 2008. The prescription of omeprazole decreased from 42.2% to 26.7%, while that of esomeprazole remained costant. The reimbursement purpose was higher for G (CAGR +43% than for ARD (CAGR +7%. We found an increase of lansoprazole prescriptions especially for heartburn (CAGR +52.4%, gastroesophageal reflux (CAGR 34,5% and upper abdominal pain (CAGR 37,2%. Generic PPIs has unexpectedly increased the prescription of whole drug class during the period 2005-2008. Our data suggest that the appropriateness of PPI prescription after generic PPI introduction should be carefully monitored to distinguish between cost-effective from cost-ineffective PPI treatment.

  4. In-hospital gastric protection with proton pump inhibitors: adverse effects beyond (overutilization?

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    Paolo Montanari

    2013-04-01

    Full Text Available Background: Proton pump inhibitors (PPIs have provided important benefits in the management of gastroesophageal reflux disease (GERD, peptic ulcer disease and in the prevention of non steroidal antiinflammatory drugs and aspirin-related ulcer complications. PPIs are also the most commonly used medications for stress ulcer prophylaxis, despite little evidence to support their use in non-intensive care unit. Discussion: Considering the widespread use of PPIs, these agents’ overall safety profile is unquestionable. However, there is growing evidence that PPIs use may be associated with an increased risk of enteric infections, pneumonia, hip fractures, vitamin B12 deficiency. Overall, until now, none of these adverse effects have discouraged the PPIs treatment. Recently attention has been placed on a more important potential adverse effect of PPIs, their interaction with clopidogrel to which they are associated for the prophylaxis of gastrointestinal bleeding. Preliminary results of laboratory tests suggest that omeprazole reduces clopidogrel’s antiplatelet effect. The interaction seems to involve the competitive inhibition of the CYP2C19 isoenzyme. The effect appears to be clinically important, as some retrospective studies have shown an increase in adverse cardiovascular outcomes when PPIs and clopidogrel are used concomitantly. Some studies indicate that pantoprazole and esomeprazole are not associated with impaired response to clopidogrel. However, the available data for PPIs other than omeprazole do not allow definitive conclusions to be drawn about whether is a class effect. Conclusions: Specifically designed and randomized clinical studies are needed to define the interaction between PPIs and clopidogrel. Moreover, alternative treatment strategies with histamine- 2 receptor antagonists that are not dependent on cytochrome p450 2C19 should be tested in future studies.

  5. East Asian perspective on the interaction between proton pump inhibitors and clopidogrel.

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    Zou, Duowu; Goh, Khean-Lee

    2017-06-01

    Both proton pump inhibitors (PPIs) and clopidogrel are widely prescribed in the Asia-Pacific population. PPIs are the mainstay therapeutic agents for prophylaxis against aspirin gastropathy and for acid-related disorders including gastroesophageal reflux disease. They are also co-prescribed with oral anticoagulant agents and with dual-antiplatelet therapy for the treatment and prevention of gastrointestinal bleeding. Clopidogrel belongs to the drug class of thienopyridines and is currently the most widely prescribed oral anticoagulant agent either alone or in combination with aspirin. Platelet inhibition by clopidogrel is prone to significant inter-individual variability and is believed to be affected by several factors such as genetics and drug-drug interactions. Since it was first reported in 2009, the potential for drug-drug interactions between PPIs and clopidogrel has remained headline news, and its significance in clinical practice is the subject of an ongoing debate. For East Asian patients in particular, the clinical relevance of the interaction between PPIs and clopidogrel remains unclear because of conflicting data, as well as underrepresentation of East Asian subjects in landmark trials. Increased CYP2C19 genetic polymorphisms in individuals from Asia-Pacific countries only fuel the confusion. Recent studies in East Asian cohorts suggests that the potential of PPIs to attenuate the efficacy of clopidogrel could be minimized by the use of newer PPIs with weaker affinity for the CYP2C19 isoenzyme, namely, pantoprazole, dexlansoprazole, and rabeprazole. This review aims to help clinicians choose the most appropriate PPI for co-prescription with clopidogrel in patients from Asia-Pacific countries. © 2016 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  6. Improved Model of Proton Pump Crystal Structure Obtained by Interactive Molecular Dynamics Flexible Fitting Expands the Mechanistic Model for Proton Translocation in P-Type ATPases.

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    Focht, Dorota; Croll, Tristan I; Pedersen, Bjorn P; Nissen, Poul

    2017-01-01

    The plasma membrane H(+)-ATPase is a proton pump of the P-type ATPase family and essential in plants and fungi. It extrudes protons to regulate pH and maintains a strong proton-motive force that energizes e.g., secondary uptake of nutrients. The only crystal structure of a H(+)-ATPase (AHA2 from Arabidopsis thaliana) was reported in 2007. Here, we present an improved atomic model of AHA2, obtained by a combination of model rebuilding through interactive molecular dynamics flexible fitting (iMDFF) and structural refinement based on the original data, but using up-to-date refinement methods. More detailed map features prompted local corrections of the transmembrane domain, in particular rearrangement of transmembrane helices 7 and 8, and the cytoplasmic N- and P-domains, and the new model shows improved overall quality and reliability scores. The AHA2 structure shows similarity to the Ca(2+)-ATPase E1 state, and provides a valuable starting point model for structural and functional analysis of proton transport mechanism of P-type H(+)-ATPases. Specifically, Asp684 protonation associated with phosphorylation and occlusion of the E1P state may result from hydrogen bond interaction with Asn106. A subsequent deprotonation associated with extracellular release in the E2P state may result from an internal salt bridge formation to an Arg655 residue, which in the present E1 state is stabilized in a solvated pocket. A release mechanism based on an in-built counter-cation was also later proposed for Zn(2+)-ATPase, for which structures have been determined in Zn(2+) released E2P-like states with the salt bridge interaction formed.

  7. Proton Pump Inhibitors Inhibit Pancreatic Secretion: Role of Gastric and Non-Gastric H+/K+-ATPases.

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    Jing Wang

    Full Text Available The mechanism by which pancreas secretes high HCO3- has not been fully resolved. This alkaline secretion, formed in pancreatic ducts, can be achieved by transporting HCO3- from serosa to mucosa or by moving H+ in the opposite direction. The aim of the present study was to determine whether H+/K+-ATPases are expressed and functional in human pancreatic ducts and whether proton pump inhibitors (PPIs have effect on those. Here we show that the gastric HKα1 and HKβ subunits (ATP4A; ATP4B and non-gastric HKα2 subunits (ATP12A of H+/K+-ATPases are expressed in human pancreatic cells. Pumps have similar localizations in duct cell monolayers (Capan-1 and human pancreas, and notably the gastric pumps are localized on the luminal membranes. In Capan-1 cells, PPIs inhibited recovery of intracellular pH from acidosis. Furthermore, in rats treated with PPIs, pancreatic secretion was inhibited but concentrations of major ions in secretion follow similar excretory curves in control and PPI treated animals. In addition to HCO3-, pancreas also secretes K+. In conclusion, this study calls for a revision of the basic model for HCO3- secretion. We propose that proton transport is driving secretion, and that in addition it may provide a protective pH buffer zone and K+ recirculation. Furthermore, it seems relevant to re-evaluate whether PPIs should be used in treatment therapies where pancreatic functions are already compromised.

  8. A phylogenetically distinctive and extremely heat stable light-driven proton pump from the eubacterium Rubrobacter xylanophilus DSM 9941T.

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    Kanehara, Kanae; Yoshizawa, Susumu; Tsukamoto, Takashi; Sudo, Yuki

    2017-03-14

    Rhodopsins are proteins that contain seven transmembrane domains with a chromophore retinal and that function as photoreceptors for light-energy conversion and light-signal transduction in a wide variety of organisms. Here we characterized a phylogenetically distinctive new rhodopsin from the thermophilic eubacterium Rubrobacter xylanophilus DSM 9941T that was isolated from thermally polluted water. Although R. xylanophilus rhodopsin (RxR) is from Actinobacteria, it is located between eukaryotic and archaeal rhodopsins in the phylogenetic tree. Escherichia coli cells expressing RxR showed a light-induced decrease in environmental pH and inhibition by a protonophore, indicating that it works as a light-driven outward proton pump. We characterized purified RxR spectroscopically, and showed that it has an absorption maximum at 541 nm and binds nearly 100% all-trans retinal. The pKa values for the protonated retinal Schiff base and its counterion were estimated to be 10.7 and 1.3, respectively. Time-resolved flash-photolysis experiments revealed the formation of a red-shifted intermediate. Of note, RxR showed an extremely high thermal stability in comparison with other proton pumping rhodopsins such as thermophilic rhodopsin TR (by 16-times) and bacteriorhodopsin from Halobacterium salinarum (HsBR, by 4-times).

  9. Masking of 13C urea breath test by proton pump inhibitors is dependent on type of medication: comparison between omeprazole, pantoprazole, lansoprazole and esomeprazole.

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    Levine, A; Shevah, O; Shabat-Sehayek, V; Aeed, H; Boaz, M; Moss, S F; Niv, Y; Avni, Y; Shirin, H

    2004-07-01

    The need to withhold acid suppression therapy while awaiting urea breath test results is a common clinical problem in symptomatic patients. It is unclear at present if the dose or type of proton pump inhibitor or the type of test meal govern the apparent masking effect of proton pump inhibitors on the urea breath test. To prospectively evaluate Helicobacter pylori detection rates during treatment with four different proton pump inhibitors, utilizing a high-dose citric acid-based 13C urea breath test. Patients positive for Helicobacter pylori by urea breath test were randomized to receive either omeprazole 20 mg/day, pantoprazole 40 mg/day, lansoprazole 30 mg/day or esomeprazole 40 mg/day for 14 days. A repeat breath test was performed on day 14 of treatment. One hundred and seventy-nine patients, mean age 45.8 +/- 16.8, completed the study. Treatment with omeprazole or pantoprazole prior to urea breath test (UBT) was associated with low false negative results, while lansoprazole and esomeprazole caused clinically unacceptable high false negative rates (pantoprazole 2.2% vs. lansoprazole 16.6%, P = 0.02, vs. esomeprazole 13.6%, P = 0.05; omeprazole 4.1% vs. lansoprazole 16.6%, P = 0.05). Proton pump inhibitor-induced false negative results on high-dose citric acid based urea breath test vary with the type of proton pump inhibitor used. Selection of the appropriate test meal and proton pump inhibitor may allow symptomatic individuals to continue their proton pump inhibitors prior to performing a urea breath test.

  10. The cost-effectiveness of high-dose oral proton pump inhibition after endoscopy in the acute treatment of peptic ulcer bleeding.

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    Barkun, A N; Herba, K; Adam, V; Kennedy, W; Fallone, C A; Bardou, M

    2004-07-15

    Recent data suggest a role for high-dose oral proton pump inhibition in ulcer bleeding. To compare the cost-effectiveness of oral high-dose proton pump inhibition to both high-dose intravenous proton pump inhibition and placebo administration. The model adopted a 30-day time horizon, and focused on patients with ulcer haemorrhage initially treated endoscopically for high-risk stigmata. Re-bleeding rates were set a priori based on non-head-to-head data from the literature, and charges and lengths of stay from a national American database. Sensitivity analyses were carried across a broad range of clinically relevant assumptions. Re-bleeding rates for patients receiving intravenous, oral, or placebo therapies were 5.9%, 11.8%, and 27%, respectively. The mean lengths of stay and costs for admitted patients with and without re-bleeding were 4.7 and 3 days; $11,802, and $7993, respectively. High-dose intravenous proton pump inhibition was more effective and less costly (dominant) than high-dose oral proton pump inhibition with incremental savings of $136.40 per patient treated. The oral high-dose strategy in turn dominated placebo administration. Results remained robust according to one- and two-way sensitivity analyses. In patients undergoing endoscopic haemostasis, subsequent high-dose intravenous proton pump inhibition is more cost-effective than high-dose oral proton pump inhibition, which in turn dominates placebo. The results from this exploratory-type cost analysis require confirmation by head-to-head prospective trials performed in Western populations.

  11. Proton Pump Inhibitors Do Not Increase Risk for Clostridium difficile Infection in the Intensive Care Unit.

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    Faleck, David M; Salmasian, Hojjat; Furuya, E Yoko; Larson, Elaine L; Abrams, Julian A; Freedberg, Daniel E

    2016-11-01

    Patients in the intensive care unit (ICU) frequently receive proton pump inhibitors (PPIs) and have high rates of Clostridium difficile infection (CDI). PPIs have been associated with CDI in hospitalized patients, but ICU patients differ fundamentally from non-ICU patients and few studies have focused on PPI use exclusively in the critical care setting. We performed a retrospective cohort study to determine the associations between PPIs and health-care facility-onset CDI in the ICU. We analyzed data from all adult ICU patients at three affiliated hospitals (14 ICUs) between 2010 and 2013. Patients were excluded if they had recent CDI or an ICU stay of Health-care facility-onset CDI in the ICU was defined as a newly positive PCR for the C. difficile toxin B gene from an unformed stool, with subsequent receipt of anti-CDI therapy. We analyzed PPIs and other exposures as time-varying covariates and used Cox proportional hazards models to adjust for demographics, comorbidities, and other clinical factors. Of 18,134 patients who met the criteria for inclusion, 271 (1.5%) developed health-care facility-onset CDI in the ICU. Receipt of antibiotics was the strongest risk factor for CDI (adjusted HR (aHR) 2.79; 95% confidence interval (CI), 1.50-5.19). There was no significant increase in risk for CDI associated with PPIs in those who did not receive antibiotics (aHR 1.56; 95% CI, 0.72-3.35), and PPIs were actually associated with a decreased risk for CDI in those who received antibiotics (aHR 0.64; 95% CI, 0.48-0.83). There was also no evidence of increased risk for CDI in those who received higher doses of PPIs. Exposure to antibiotics was the most important risk factor for health-care facility-onset CDI in the ICU. PPIs did not increase risk for CDI in the ICU regardless of use of antibiotics.

  12. [What is the utility of proton pump inhibitor testing in non-cardiac chest pain?].

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    Huamán, José Wálter; Aliaga, Verónica; Domenech, Gemma; Videla, Sebastián; Saperas, Esteban

    2014-10-01

    Noncardiac chest pain (NCCP) often represents a diagnostic and therapeutic challenge. Given that gastroesophageal reflux disease (GERD) is the most common cause of NCCP, initial treatment with proton-pump inhibitors (PPI) has been proposed for all patients (PPI testing), reserving esophageal function testing solely for non-responders. The aim of the present study was to provide evidence on the clinical utility of PPI testing with high-dose pantoprazole in patients with NCCP. We carried out a study of diagnostic performance with a cohort design in patients with NCCP, who had been assessed by the Cardiology Service. All patients underwent upper endoscopy, esophageal manometry, and 24h esophageal pH monitoring before PPI testing with pantoprazole 40 mg every 12h for 1 month. Before and after treatment, we assessed the severity (intensity and frequency) of chest pain, quality of life, and anxiety and depression by means of specific questionnaires. The diagnosis of GERD was based on a pathological finding of esophageal pH monitoring. A positive response to PPI testing was defined as an improvement in chest pain >50% compared with the baseline score after 1 month of PPI therapy. We included 30 consecutive patients (17 men/13 women) with a mean age of 49 years. Of these 30 patients, 20 with NCCP had GERD (67%, 95%CI: 47%-83%). A positive response to PPI therapy was observed in 13 of the 30 (43%) patients with NCCP: 11 of the 20 (55%) patients in the GERD-positive group and 2 of the 10 (20%) in the GERD-negative group. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PPI testing was 55%, 80%, 85%, 47% and 63%, respectively. A significant reduction in chest pain after pantoprazole therapy (P=.003) and a slight non significant improvement in anxiety and depression was achieved in the GERD-positive group as compared to the GERD-negative group. In NCCP, PPI testing with pantoprazole has a low sensitivity for the diagnosis of

  13. Pleiotropic effect of the proton pump inhibitor esomeprazole leading to suppression of lung inflammation and fibrosis.

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    Ghebremariam, Yohannes T; Cooke, John P; Gerhart, William; Griego, Carol; Brower, Jeremy B; Doyle-Eisele, Melanie; Moeller, Benjamin C; Zhou, Qingtao; Ho, Lawrence; de Andrade, Joao; Raghu, Ganesh; Peterson, Leif; Rivera, Andreana; Rosen, Glenn D

    2015-08-01

    The beneficial outcome associated with the use of proton pump inhibitors (PPIs) in idiopathic pulmonary fibrosis (IPF) has been reported in retrospective studies. To date, no prospective study has been conducted to confirm these outcomes. In addition, the potential mechanism by which PPIs improve measures of lung function and/or transplant-free survival in IPF has not been elucidated. Here, we used biochemical, cell biological and preclinical studies to evaluate regulation of markers associated with inflammation and fibrosis. In our in vitro studies, we exposed primary lung fibroblasts, epithelial and endothelial cells to ionizing radiation or bleomycin; stimuli typically used to induce inflammation and fibrosis. In addition, we cultured lung fibroblasts from IPF patients and studied the effect of esomeprazole on collagen release. Our preclinical study tested efficacy of esomeprazole in a rat model of bleomycin-induced lung injury. Furthermore, we performed retrospective analysis of interstitial lung disease (ILD) databases to examine the effect of PPIs on transplant-free survival. The cell culture studies revealed that esomeprazole controls inflammation by suppressing the expression of pro-inflammatory molecules including vascular cell adhesion molecule-1, inducible nitric oxide synthase, tumor necrosis factor-alpha (TNF-α) and interleukins (IL-1β and IL-6). The antioxidant effect is associated with strong induction of the stress-inducible cytoprotective protein heme oxygenase-1 (HO1) and the antifibrotic effect is associated with potent inhibition of fibroblast proliferation as well as downregulation of profibrotic proteins including receptors for transforming growth factor β (TGFβ), fibronectin and matrix metalloproteinases (MMPs). Furthermore, esomeprazole showed robust effect in mitigating the inflammatory and fibrotic responses in a murine model of acute lung injury. Finally, retrospective analysis of two ILD databases was performed to assess the effect

  14. Regulatory assembly of the vacuolar proton pump VoV1-ATPase in yeast cells by FLIM-FRET

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    Ernst, Stefan; Batisse, Claire; Zarrabi, Nawid; Böttcher, Bettina; Börsch, Michael

    2010-02-01

    We investigate the reversible disassembly of VOV1-ATPase in life yeast cells by time resolved confocal FRET imaging. VOV1-ATPase in the vacuolar membrane pumps protons from the cytosol into the vacuole. VOV1-ATPase is a rotary biological nanomotor driven by ATP hydrolysis. The emerging proton gradient is used for secondary transport processes as well as for pH and Ca2+ homoeostasis in the cell. The activity of the VOV1-ATPase is regulated through assembly / disassembly processes. During starvation the two parts of VOV1-ATPase start to disassemble. This process is reversed after addition of glucose. The exact mechanisms are unknown. To follow the disassembly / reassembly in vivo we tagged two subunits C and E with different fluorescent proteins. Cellular distributions of C and E were monitored using a duty cycle-optimized alternating laser excitation scheme (DCO-ALEX) for time resolved confocal FRET-FLIM measurements.

  15. The influence of hospital drug formulary policies on the prescribing patterns of proton pump inhibitors in primary care

    DEFF Research Database (Denmark)

    Larsen, Michael Due; Schou, Mette; Kristiansen, Anja Sparre

    2014-01-01

    AIM: This study had two aims: Firstly, to describe how prescriptions for proton pump inhibitor (PPI) in primary care were influenced by a change of the hospital drug policy, and secondly, to describe if a large discount on an expensive PPI (esomeprazole) to a hospital would influence prescribing...... decreased from 33.5 to 9.4 %, corresponding to a risk ratio of 0.28. In primary care after discharge, 13.4 % of esomeprazole use was initiated in the hospital, and this was 8.4 % for PPIs in general. After the change of hospital drug policy, this decreased to 6.5 % for esomeprazole and increased...

  16. Oral versus intravenous proton pump inhibitors in preventing re-bleeding for patients with peptic ulcer bleeding after successful endoscopic therapy.

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    Yen, Hsu-Heng; Yang, Chia-Wei; Su, Wei-Wen; Soon, Maw-Soan; Wu, Shun-Sheng; Lin, Hwai-Jeng

    2012-06-08

    High dose intravenous proton pump inhibitor after endoscopic therapy for peptic ulcer bleeding has been recommended as adjuvant therapy. Whether oral proton pump inhibitor can replace intravenous proton pump inhibitor in this setting is unknown. This study aims to compare the clinical efficacy of oral and intravenous proton pump inhibitor after endoscopic therapy. Patients with high-risk bleeding peptic ulcers after successful endoscopic therapy were randomly assigned as oral lansoprazole or intravenous esomeprazole group. Primary outcome of the study was re-bleeding rate within 14 days. Secondary outcome included hospital stay, volume of blood transfusion, surgical intervention and mortality within 1 month. From April 2010 to Feb 2011, 100 patients were enrolled in this study. The re-bleeding rates were 4% (2/50) in the intravenous group and 4% (2/50) in the oral group. There was no difference between the two groups with regards to the hospital stay, volume of blood transfusion, surgery or mortality rate. The mean duration of hospital stay was 1.8 days in the oral lansoprazole group and 3.9 days in the intravenous esomeprazole group (p > 0.01). Patients receiving oral proton pump inhibitor have a shorter hospital stay. There is no evidence of a difference in clinical outcomes between oral and intravenous PPI treatment. However, the study was not powered to prove equivalence or non-inferiority. Future studies are still needed. NCT01123031.

  17. Tritium Sequestration in Gen IV NGNP Gas Stream via Proton Conducting Ceramic Pumps

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Fanglin Frank [Univ. of South Carolina, Columbia, SC (United States); Adams, Thad M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Reifsnider, Kenneth [Univ. of South Carolina, Columbia, SC (United States)

    2011-09-30

    Several types of high-temperature proton conductors based on SrCeO3 and BaCeO3 have been systematically investigated in this project for tritium separation in NGNP applications. One obstacle for the field application is the chemical stability issues in the presence of steam and CO2 for these proton conductors. Several strategies to overcome such issues have been evaluated, including A site doping and B site co-doping method for perovskite-structured proton conductors. Novel zirconium-free proton conductors have also been developed with improved electrical conductivity and enhanced chemical stability. Novel catalytic materials for the proton-conducting separation membranes have been investigated. A tubular geometry proton-conducting membrane has been developed for the proton separation membranes. Total dose rate estimated from tritium decay (beta emission) under realistic membrane operating conditions, combined with electron irradiation experiments, indicates that proton ceramic materials possess the appropriate radiation stability for this application.

  18. The Ca(2+)-ATPase pump facilitates bidirectional proton transport across the sarco/endoplasmic reticulum.

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    Espinoza-Fonseca, L Michel

    2017-03-28

    Ca(2+) transport across the sarco/endoplasmic reticulum (SR) plays an essential role in intracellular Ca(2+) homeostasis, signalling, cell differentiation and muscle contractility. During SR Ca(2+) uptake and release, proton fluxes are required to balance the charge deficit generated by the exchange of Ca(2+) and other ions across the SR. During Ca(2+) uptake by the SR Ca(2+)-ATPase (SERCA), two protons are countertransported from the SR lumen to the cytosol, thus partially compensating for the charge moved by Ca(2+) transport. Studies have shown that protons are also transported from the cytosol to the lumen during Ca(2+) release, but a transporter that facilitates proton transport into the SR lumen has not been described. In this article we propose that SERCA forms pores that facilitate bidirectional proton transport across the SR. We describe the location and structure of water-filled pores in SERCA that form cytosolic and luminal pathways for protons to cross the SR membrane. Based on this structural information, we suggest mechanistic models for proton translocation to the cytosol during active Ca(2+) transport, and into the SR lumen during SERCA inhibition by endogenous regulatory proteins. Finally, we discuss the physiological consequences of SERCA-mediated bidirectional proton transport across the SR membrane of muscle and non-muscle cells.

  19. Are proton pump inhibitors the first choice for acute treatment of gastric ulcers? A meta analysis of randomized clinical trials

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    Ward Alexandra

    2002-07-01

    Full Text Available Abstract Background Gastric ulcers are a frequent problem in the United States. Proton pump inhibitors have been shown to increase healing rates and improve clinical symptoms. The objective of this study is to compare gastric ulcer healing rates for patients treated with a proton pump inhibitor (PPI (omeprazole, rabeprazole, pantoprazole, or lansoprazole, an histamine 2- receptor antagonist (ranitidine or placebo. Methods A literature search was conducted to identify randomized, controlled clinical trials that included a PPI in at least one treatment arm and assessed the gastric ulcer healing rates endoscopically. The healing rates were estimated for each treatment at specific time points, and Rate Ratios (RR and 95% confidence intervals (CI were estimated for each trial. Results Sixteen trials met the inclusion criteria: four compared a PPI versus placebo, nine compared a PPI versus ranitidine (no trials of rabeprazole versus ranitidine met the inclusion criteria, and three compared a newer PPI (lansoprazole, pantoprazole or rabeprazole versus omeprazole. In relation to ranitidine, the pooled RR of PPIs (lansoprazole, omeprazole and pantoprazole was 1.33 (95% CI 1.24 to 1.42 at four weeks. In each trial, greater improvement in the studied clinical symptoms was found with the newer PPIs (rabeprazole, pantoprazole and lansoprazole when compared to omeprazole. Conclusion In this study treatment with PPIs resulted in higher healing rates than ranitidine or placebo. This evidence suggests that the first choice for gastric ulcer treatment for the greater relief of symptoms is one of the newer PPIs.

  20. Oral proton pump inhibitors disrupt horizontal cell-cone feedback and enhance visual hallucinations in macular degeneration patients.

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    Hanneken, Anne M; Babai, Norbert; Thoreson, Wallace B

    2013-02-27

    Visual hallucinations (VHs) occur in macular degeneration patients with poor vision but normal cognitive function. The underlying mechanisms are poorly understood. We report the identification of pharmaceutical agents that enhance VH and use these agents to examine the contribution of retinal neurons to this syndrome. We detail clinical observations on VH in five macular degeneration patients treated with proton pump inhibitors having the core structure, 2-pyridyl-methylsulfinyl-benzimidazole. We tested possible retinal mechanisms using paired whole cell recordings to examine effects of these compounds on feedback interactions between horizontal cells and cones in amphibian retina. Five patients with advanced wet macular degeneration described patterned VHs that were induced or enhanced by oral proton pump inhibitors. The abnormal images increased with light, disappeared in the dark, and originated in the retina, based on ophthalmodynamometry. Simultaneous paired whole cell recordings from amphibian cones and horizontal cells showed that 2-pyridyl-methylsulfinyl-benzimidazoles blocked the negative shift in voltage dependence and increase in amplitude of the calcium current (ICa) in cones that is induced by changes in horizontal cell membrane potential. These effects disrupt the negative feedback from horizontal cells to cones that is important for the formation of center-surround receptive fields in bipolar and ganglion cells, and thus for normal spatial and chromatic perception. Our study suggests that changes in the output of retinal neurons caused by disturbances in outer retinal feedback mechanisms can enhance patterned visual hallucinations.

  1. A rapid Fourier transform infrared spectroscopic method for analysis of certain proton pump inhibitors in binary and ternary mixtures

    Science.gov (United States)

    Khashaba, Pakinaz Y.; Ali, Hassan Refat H.; El-Wekil, Mohamed M.

    2018-02-01

    A simple and non-destructive FTIR method was used to determine certain proton pump inhibitors (PPIs) in binary and ternary mixtures. Proton pump inhibitors (PPIs); omeprazole (OMZ), esomeprazole (EZM), lansoprazole (LAN), pantoprazole sodium (PAN sodium) and rabeprazole sodium (RAB sodium) in binary mixture with domperidone (DOM) and ternary mixture of OMZ, clarithromycin (CLM) and tinidazole (TNZ) were determined in the solid-state by FTIR spectroscopy for the first time. The method was validated according to ICH-guidelines where linearity was ranged from 20 to 850 μg/g and 20-360 μg/g for PPIs and DOM, respectively in binary mixtures and 10-400, 100-8000 and 150-14,000 μg/g for OMZ, CLM and TNZ, respectively. Limits of detection were found to be 6-100 and 9-100 μg/g for PPIs and DOM, respectively and 4, 40 and 50 μg/g for OMZ, CLM and TNZ, respectively. The method was applied successfully for determination of the cited drugs in their respective pharmaceutical dosage forms.

  2. Effect of proton pump inhibitors on platelet inhibition activity of clopidogrel in Chinese patients with percutaneous coronary intervention

    Directory of Open Access Journals (Sweden)

    Kwan T

    2011-06-01

    Full Text Available Joanne Kwan1, Wah Wah Htun2, Yili Huang3, Wilson Ko3, Tak W Kwan31Boston University, Boston, MA, USA; 2Lutheran Medical Center, Brooklyn, NY, USA; 3Beth Israel Medical Center, New York, NY, USABackground: The purpose of this study was to examine the effect of proton pump inhibitors (PPI on the antiplatelet activity of clopidogrel in a consecutive series of Chinese patients after they had received coronary stents.Methods: A sample of 51 consecutive Chinese patients treated with coronary stents and taking PPI and clopidogrel for more than 30 days were enrolled in this study. Mean values for platelet residual units and percentage inhibition before PPI (+PPI and 14 days after discontinuation of PPI (-PPI were compared using the paired t-test.Results: There was no effect of concomitant use of esomeprazole and clopidogrel or omeprazole and clopidogrel on the inhibition assay, but platelet residual units and percentage inhibition showed statistically significant improvement after stopping lansoprazole in Chinese patients who were on chronic clopidogrel therapy. Clopidogrel resistance existed more frequently in the Chinese-American population examined, and was as high as 68% (+PPI to 73% (-PPI.Conclusion: The clopidogrel resistance found is cause for concern, although its relationship with clinical events is currently unknown in this population. Further study with other thienopyridines or genetic variant analysis is suggested.Keywords: proton pump inhibitors, clopidogrel resistance, Chinese population, percutaneous coronary intervention

  3. Yb:LiNbO3 Annealed/Proton-Exchanged Waveguide Lasers Pumped by InGaAs Laser Diode at 980 nm Wavelength

    Science.gov (United States)

    Fujimura, Masatoshi; Tsuchimoto, Hidekazu; Suhara, Toshiaki

    2007-08-01

    Various waveguide lasers in rare-earth-doped LiNbO3 have been studied, and an Yb:LiNbO3 annealed/proton-exchanged (APE) waveguide laser pumped at a 918 nm wavelength has been reported recently. In this paper, an Yb:LiNbO3 APE waveguide laser pumped at a 980 nm wavelength is proposed and demonstrated. Pumping at 980 nm allows the use of a commercially available InGaAs laser diode for a pump source instead of a Ti:Al2O3 laser used in the previous work. The longer pump wavelength is favorable to avoid photorefractive damage. A prototype device was designed, fabricated and tested. Laser oscillation was achieved at 1061 nm wavelength with a threshold pump power of 30 mW. An output power of 4.3 mW was obtained, which was three-orders of magnitude larger than that obtained in the previous work.

  4. Engineering bacterial efflux pumps for solar-powered bioremediation of surface waters.

    Science.gov (United States)

    Kapoor, Vikram; Wendell, David

    2013-05-08

    Antibiotics are difficult to selectively remove from surface waters by present treatment methods. Bacterial efflux pumps have evolved the ability to discriminately expel antibiotics and other noxious agents via proton and ATP driven pathways. Here, we describe light-dependent removal of antibiotics by engineering the bacterial efflux pump AcrB into a proteovesicle system. We have created a chimeric protein with the requisite proton motive force by coupling AcrB to the light-driven proton pump Delta-rhodopsin (dR) via a glycophorin A transmembrane domain. This creates a solar powered protein material capable of selectively capturing antibiotics from bulk solutions. Using environmental water and direct sunlight, our AcrB-dR vesicles removed almost twice as much antibiotic as the treatment standard, activated carbon. Altogether, the AcrB-dR system provides an effective means of extracting antibiotics from surface waters as well as potential antibiotic recovery through vesicle solubilization.

  5. Role of protons in the pump cycle of KdpFABC investigated by time-resolved kinetic experiments.

    Science.gov (United States)

    Damnjanovic, Bojana; Apell, Hans-Jürgen

    2014-05-20

    The time-resolved kinetics of the KdpFABC complex solubilized in Aminoxide WS-35 was investigated by ATP concentration jump experiments. ATP was photoreleased from its inactive precursor, caged ATP, and charge movements in the membrane domain of the KdpFABC were detected by the electrochromic dye RH421. At low ATP concentrations, the ATP binding step became rate-limiting with an apparent, pH-independent ATP binding affinity of ~70 μM. At saturating ATP concentrations, the rate-limiting step is the conformational transition (E1-P → P-E2) with a rate constant of ~1.7 s(-1) at 20 °C that was independent of K(+) concentration. This observation together with the detected fluorescence decrease indicates that K(+) (or another positive ion) is bound in the membrane domain after enzyme phosphorylation and the conformational transition to the P-E2 state. pH dependence experiments revealed different roles of H(+) in the transport mechanism. Two different functions of protons for the ion pump must be distinguished. On one hand, there are electrogenically bound "functional" protons, which are not transported but prerequisite for the performance of the ATP-driven half-cycle. On the other hand, protons bind to the transport sites, acting as weak congeners of K(+). There possibly are noncompetitively bound protons, affecting the enzyme activity and/or coupling between KdpA and KdpB subunits. Finally, the recently proposed Post-Albers model for the KdpFABC complex was supplemented with stoichiometry factors of 2 for K(+) and 3 for H(+), and additional inhibitory side reactions controlled by H(+) were introduced, which are relevant at pH <6.5 and/or in the absence of K(+).

  6. Biophysical comparison of ATP-driven proton pumping mechanisms suggests a kinetic advantage for the rotary process depending on coupling ratio.

    Science.gov (United States)

    Anandakrishnan, Ramu; Zuckerman, Daniel M

    2017-01-01

    ATP-driven proton pumps, which are critical to the operation of a cell, maintain cytosolic and organellar pH levels within a narrow functional range. These pumps employ two very different mechanisms: an elaborate rotary mechanism used by V-ATPase H+ pumps, and a simpler alternating access mechanism used by P-ATPase H+ pumps. Why are two different mechanisms used to perform the same function? Systematic analysis, without parameter fitting, of kinetic models of the rotary, alternating access and other possible mechanisms suggest that, when the ratio of protons transported per ATP hydrolyzed exceeds one, the one-at-a-time proton transport by the rotary mechanism is faster than other possible mechanisms across a wide range of driving conditions. When the ratio is one, there is no intrinsic difference in the free energy landscape between mechanisms, and therefore all mechanisms can exhibit the same kinetic performance. To our knowledge all known rotary pumps have an H+:ATP ratio greater than one, and all known alternating access ATP-driven proton pumps have a ratio of one. Our analysis suggests a possible explanation for this apparent relationship between coupling ratio and mechanism. When the conditions under which the pump must operate permit a coupling ratio greater than one, the rotary mechanism may have been selected for its kinetic advantage. On the other hand, when conditions require a coupling ratio of one or less, the alternating access mechanism may have been selected for other possible advantages resulting from its structural and functional simplicity.

  7. Comparison of different regimens of proton pump inhibitors for acute peptic ulcer bleeding.

    Science.gov (United States)

    Neumann, Ignacio; Letelier, Luz M; Rada, Gabriel; Claro, Juan Carlos; Martin, Janet; Howden, Colin W; Yuan, Yuhong; Leontiadis, Grigorios I

    2013-06-12

    Treatment with proton pump inhibitors (PPIs) improves clinical outcomes in patients with peptic ulcer bleeding. However, the optimal dose and route of administration of PPIs remains controversial. To evaluate the efficacy of different regimens of PPIs in the management of acute peptic ulcer bleeding using evidence from direct comparison randomized controlled trials (RCTs).We specifically intended to assess the differential effect of the dose and route of administration of PPI on mortality, rebleeding, surgical intervention, further endoscopic haemostatic treatment (EHT), length of hospital stay, transfusion requirements and adverse events. We searched CENTRAL (in The Cochrane Library 2010, Issue 3), MEDLINE and EMBASE (from inception to September 2010) and proceedings of major gastroenterology meetings (January 2000 to September 2010), without language restrictions. Original investigators were contacted to request missing data. RCTs that compared at least two different regimens of the same or a different PPI in patients with acute peptic ulcer bleeding, diagnosed endoscopically. Two reviewers independently selected studies, extracted data and assessed risk of bias. We synthesized data using the Mantel-Haenszel random-effects method and performed multivariate meta-regression with random permutations based on Monte Carlo simulation. We measured heterogeneity with the I² statistic and Cochrane Q test and assessed publication bias with funnel plots and Egger's test. We graded the overall quality of evidence using the GRADE approach. Twenty two RCTs were included; risk of bias was high in 17 and unclear in 5. The main analysis included 13 studies (1716 patients) comparing "high" dose regimens (72-hour cumulative dose > 600 mg of intravenous PPI) to other doses; there was no significant heterogeneity for any clinical outcome. We found low quality evidence that did not exclude a potential reduction or increase in mortality, rebleeding, surgical interventions or

  8. Pharmacoeconomic analysis of proton pump inhibitor therapy and interventions to control Helicobacter pylori infection

    NARCIS (Netherlands)

    Klok, Rogier Martijn

    2006-01-01

    In dit proefschrift worden de farmacoeconomische aspecten van problemen in het bovenste deel van het gastrointestinale tract besproken. De uitwisselbaarheid van proton pomp remmers (PPRs) wordt besproken net als switch patronen na het aflopen van het patent van omeprazol, de eerste PPR op de

  9. Resolution of Fundic Gland Polyposis following Laparoscopic Magnetic Sphincter Augmentation and Subsequent Cessation of Proton Pump Inhibitors

    Directory of Open Access Journals (Sweden)

    Joel R. Brockmeyer

    2015-01-01

    Full Text Available Gastric polyps occur from a variety of sources and are found commonly on upper endoscopy. We present the case of a 49-year-old female who presented for evaluation for antireflux surgery with a history of fundic gland polyposis who required twice-daily proton pump inhibitors (PPIs for control of her gastric reflux. After verifying that she met criteria for surgery, she underwent an uncomplicated laparoscopic magnetic sphincter augmentation placement. With the cessation of PPIs following surgery, the fundic gland polyposis resolved. Fundic gland polyps may occur sporadically or within certain syndromes, such as familial adenomatous polyposis. Multiple possible inciting factors exist, including the use of PPIs. This is the first reported case of the resolution of numerous fundic gland polyps following the completion of laparoscopic magnetic sphincter augmentation.

  10. Concomitant use of clopidogrel and proton pump inhibitors is not associated with major adverse cardiovascular events following coronary stent implantation

    DEFF Research Database (Denmark)

    Schmidt, M; Johansen, M B; Robertson, D J

    2012-01-01

    Aliment Pharmacol Ther 2012; 35: 165-174 SUMMARY: Background  Cytochrome P450 inhibition by proton pump inhibitors (PPIs) may attenuate the effectiveness of clopidogrel. Aim  To examine whether PPI use modifies the association between clopidogrel use and major adverse cardiovascular events (MACE.......97-1.58) for clopidogrel users and 1.26 (95% CI: 0.97-1.63) for clopidogrel non-users]. Conclusions  The use of PPIs as a class did not modify the protective effect of clopidogrel, but its use was associated with major adverse cardiovascular events itself, particularly among patients having used PPIs before percutaneous...... implantation between 2002 and 2005 and ascertained their reported comorbidities. During the recommended 12-month postintervention treatment period, we tracked use of clopidogrel and PPI and the rate of MACE. We used Cox regression to compute hazard ratios (HRs), controlling for potential confounders. Results...

  11. Positive Darwinian selection in the piston that powers proton pumps in complex I of the mitochondria of Pacific salmon.

    Directory of Open Access Journals (Sweden)

    Michael R Garvin

    Full Text Available The mechanism of oxidative phosphorylation is well understood, but evolution of the proteins involved is not. We combined phylogenetic, genomic, and structural biology analyses to examine the evolution of twelve mitochondrial encoded proteins of closely related, yet phenotypically diverse, Pacific salmon. Two separate analyses identified the same seven positively selected sites in ND5. A strong signal was also detected at three sites of ND2. An energetic coupling analysis revealed several structures in the ND5 protein that may have co-evolved with the selected sites. These data implicate Complex I, specifically the piston arm of ND5 where it connects the proton pumps, as important in the evolution of Pacific salmon. Lastly, the lineage to Chinook experienced rapid evolution at the piston arm.

  12. Stress ulcer prophylaxis with a proton pump inhibitor versus placebo in critically ill patients (SUP-ICU trial)

    DEFF Research Database (Denmark)

    Krag, Mette; Perner, Anders; Wetterslev, Jørn

    2016-01-01

    BACKGROUND: Critically ill patients in the intensive care unit (ICU) are at risk of clinically important gastrointestinal bleeding, and acid suppressants are frequently used prophylactically. However, stress ulcer prophylaxis may increase the risk of serious adverse events and, additionally......, the quantity and quality of evidence supporting the use of stress ulcer prophylaxis is low. The aim of the SUP-ICU trial is to assess the benefits and harms of stress ulcer prophylaxis with a proton pump inhibitor in adult patients in the ICU. We hypothesise that stress ulcer prophylaxis reduces the rate...... of gastrointestinal bleeding, but increases rates of nosocomial infections and myocardial ischaemia. The overall effect on mortality is unpredictable. METHODS/DESIGN: The SUP-ICU trial is an investigator-initiated, pragmatic, international, multicentre, randomised, blinded, parallel-group trial of stress ulcer...

  13. Effects of administration of a proton pump inhibitor before endoscopic submucosal dissection for differentiated early gastric cancer with ulcer.

    Science.gov (United States)

    Myung, Yu Sik; Hong, Su Jin; Han, Jae Pil; Park, Kyung Woo; Ko, Bong Min; Lee, Moon Sung

    2017-01-01

    In ulcerative early gastric cancer, improvement and exacerbation of ulceration repeat as a malignant cycle. Moreover, early gastric cancer combined with ulcer is associated with a low curative resection rate and high risk of adverse events. The aim of this study was to investigate the ulcer healing rate and clinical outcomes with the administration of a proton pump inhibitor before endoscopic submucosal dissection for differentiated early gastric cancer with ulcer. A total of 136 patients with differentiated early gastric cancer with ulcer who met the expanded indications for endoscopic submucosal dissection were reviewed between June 2005 and June 2014. Eighty-one patients were given PPI before endoscopic submucosal dissection and 55 patients were not given PPI. The complete ulcer healing rate was significantly different between the two groups (59.3 % vs. 23.6 %, P cancer.

  14. Synaptic vesicles are capable of synthesizing the VGLUT substrate glutamate from α-ketoglutarate for vesicular loading.

    Science.gov (United States)

    Takeda, Kouji; Ishida, Atsuhiko; Takahashi, Kento; Ueda, Tetsufumi

    2012-04-01

    Synaptic vesicle loading of glutamate is a pivotal step in glutamate synaptic transmission. The molecular machinery responsible for this step is comprised of v-type proton-pump ATPase and a vesicular glutamate transporter. Recent evidence indicates that synaptic vesicles are endowed with glycolytic ATP-synthesizing enzymes, providing energy for immediate use by vesicle-bound proton-pump ATPase. In this study, we provide evidence that synaptic vesicles are also capable of synthesizing the vesicular glutamate transporter substrate glutamate, from α-ketoglutarate and l-aspartate (as the amino group donor); glutamate thus produced is taken up into vesicles. We also report a finding that α-ketoglutarate-derived glutamate uptake into synaptic vesicles and aspartate aminotransferase are inhibited by 2,3-pyrazinedicarboxylate. Evidence is given that this is a selective inhibitor for aspartate aminotransferase. These observations provide insight into understanding the nerve endings' mechanism for high efficiency in glutamate transmission. Finding this inhibitor may have implications for further experimentation on the role of α-ketoglutarate-derived glutamate in glutamate transmission. © 2012 The Authors. Journal of Neurochemistry © 2012 International Society for Neurochemistry.

  15. Effects of 12 weeks' treatment with a proton pump inhibitor on insulin secretion, glucose metabolism and markers of cardiovascular risk in patients with type 2 diabetes

    DEFF Research Database (Denmark)

    Hove, K D; Brøns, Cecilie; Færch, Kai Erik Vinther

    2013-01-01

    Recent studies suggest that proton pump inhibitor treatment may increase insulin secretion and improve glucose metabolism in type 2 diabetes. In a randomised double-blind prospective placebo-controlled 2 × 2 factorial study, we examined the effect of esomeprazole on insulin secretion, HbA(1c...

  16. Proton pump inhibitor use and risk of adverse cardiovascular events in aspirin treated patients with first time myocardial infarction: nationwide propensity score matched study.

    Science.gov (United States)

    Charlot, Mette; Grove, Erik L; Hansen, Peter Riis; Olesen, Jonas B; Ahlehoff, Ole; Selmer, Christian; Lindhardsen, Jesper; Madsen, Jan Kyst; Køber, Lars; Torp-Pedersen, Christian; Gislason, Gunnar H

    2011-05-11

    To examine the effect of proton pump inhibitors on adverse cardiovascular events in aspirin treated patients with first time myocardial infarction. Retrospective nationwide propensity score matched study based on administrative data. Setting All hospitals in Denmark. All aspirin treated patients surviving 30 days after a first myocardial infarction from 1997 to 2006, with follow-up for one year. Patients treated with clopidogrel were excluded. The risk of the combined end point of cardiovascular death, myocardial infarction, or stroke associated with use of proton pump inhibitors was analysed using Kaplan-Meier analysis, Cox proportional hazard models, and propensity score matched Cox proportional hazard models. Results 3366 of 19,925 (16.9%) aspirin treated patients experienced recurrent myocardial infarction, stroke, or cardiovascular death. The hazard ratio for the combined end point in patients receiving proton pump inhibitors based on the time dependent Cox proportional hazard model was 1.46 (1.33 to 1.61; Paspirin treated patients with first time myocardial infarction, treatment with proton pump inhibitors was associated with an increased risk of adverse cardiovascular events.

  17. Proton pump inhibitor use and fracture risk - effect modification by histamine H1 receptor blockade. Observational case-control study using National Prescription Data

    DEFF Research Database (Denmark)

    Abrahamsen, Bo; Vestergaard, Peter

    2013-01-01

    It remains unknown why proton pump inhibitor (PPI) use may be associated with risk of osteoporotic fractures; evidence of direct effects on calcium absorption or on the osteoclast in humans is weak or absent. However, the ensuing increased gastrin levels may cause histamine production through...

  18. Lack of a clinically significant drug-drug interaction in healthy volunteers between the HCV protease inhibitor boceprevir and the proton pump inhibitor omeprazole

    NARCIS (Netherlands)

    Kanter, C.T.M.M. de; Colbers, A.P.; Blonk, M.I.; Wissen, C.P.W.G.M. van; Schouwenberg, B.J.J.W.; Drenth, J.P.H.; Burger, D.M.

    2013-01-01

    OBJECTIVES: Proton pump inhibitors (PPIs) can limit the solubility of concomitant drugs, which can lead to decreased absorption and exposure. Reduced efficacy can be a consequence and in the case of an antimicrobial agent this may contribute to development of resistance. Patients chronically

  19. A systematic comparison of triple therapies for treatment of Helicobacter pylori infection with proton pump inhibitor/ ranitidine bismuth citrate plus clarithromycin and either amoxicillin or a nitroimidazole.

    NARCIS (Netherlands)

    Janssen, M.J.R.; Oijen, A.H.A.M. van; Verbeek, A.L.M.; Jansen, J.B.M.J.; Boer, W.A. de

    2001-01-01

    BACKGROUND: Triple therapies with proton pump inhibitor/ranitidine bismuth citrate (RBC), clarithromycin (C) and either amoxicillin (A) or a nitroimidazole (I) are widely accepted as treatment for Helicobacter pylori infection. However, it is not clear which of these antibiotic combinations should

  20. Effect of proton-pump inhibitor treatment on symptoms and quality of life in GERD patients depends on the symptom-reflux association

    NARCIS (Netherlands)

    Aanen, Marissa C.; Weusten, Bas L. A. M.; Numans, Mattijs E.; de Wit, Niek J.; Samsom, Melvin; Smout, Andre J. P. M.

    2008-01-01

    Backgound: Gastroesophageal reflux disease patients demonstrate various pathophysiologic backgrounds. Therefore, a heterogeneous response to proton-pump inhibitor (PPI) treatment can be expected. We investigated the effect of short-term PPI treatment on symptoms and quality of life (QOL) in primary

  1. The effect of dose and type of proton pump inhibitor use on risk of fractures and osteoporosis treatment in older Australian women: A prospective cohort study

    NARCIS (Netherlands)

    van der Hoorn, M.M.C.; Tett, S.E.; de Vries, O.J.; Dobson, A.J.; Peeters, G.M.E.E.

    2015-01-01

    Objectives: Proton pump inhibitors (PPIs) are among the most prescribed medications worldwide, however, there is growing concern regarding potential negative effects on bone health. The aim was to examine the effect of dose and type of PPI use on subsequent use of osteoporosis medication and

  2. The effect of proton pump inhibitors on glycated hemoglobin levels in patients with type 2 diabetes mellitus.

    Science.gov (United States)

    Han, Na; Oh, Minkyung; Park, Su Min; Kim, You Jeong; Lee, Eun Ju; Kim, Tae Kyoon; Kim, Tae Nyun; Kwon, Min Jeong; Kim, Mi-Kyung; Lee, Soon Hee; Rhee, Byoung Doo; Park, Jeong Hyun

    2015-02-01

    Gastrin increases the growth and neogenesis of the islets of Langerhans. Oral proton pump inhibitors (PPIs) increase the circulating gastrin level in animals and humans, but the therapeutic benefit of PPIs for diabetes mellitus has not been resolved. We examined whether treatment with a PPI for ≥2 months affected the glycated hemoglobin (A1C) level in patients with type 2 diabetes. The electronic medical records of patients treated at the Busan Paik Hospital in South Korea were examined. The primary outcome measure was the change in A1C before and after PPI treatment for ≥2 months. We also tested if the primary outcome measure was affected by sex, age, duration of diabetes, body mass index, PPI molecule, duration of treatment with PPI or concurrent therapy with other antidiabetes agents. In total, 43 patients (17 men and 26 women) were studied (mean age 63.8 years). Patients were treated with a PPI for a mean of 180 days. The A1C levels before and after treatment were not significantly different (6.86%±1.10% and 6.77%±1.07%, respectively; p=0.406). Metformin monotherapy did not lower A1C levels as compared with a combination therapy including metformin and antidiabetes medication not including metformin. Proton pump inhibitor treatment of patients with type 2 diabetes did not reduce A1C levels. The data of this study were obtained from a retrospective chart review and included a small number of subjects. Furthermore, large randomized controlled studies are needed to define the effect of PPIs for type 2 patients with diabetes. Copyright © 2015 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

  3. Role of proton pump inhibitors in preventing hypergastrinemia-associated carcinogenesis and in antagonizing the trophic effect of gastrin.

    Science.gov (United States)

    Han, Y-M; Park, J-M; Kangwan, N; Jeong, M; Lee, S; Cho, J Y; Ko, W J; Hahm, K B

    2015-04-01

    Gastrin is the main hormone stimulating gastric acid secretion, but it exerts proliferative and anti-apoptotic actions on various cancer cell types, in addition to its well-known trophic effect on enterochromaffin-like cells. As treatment with proton pump inhibitors (PPIs) increases the biosynthesis and secretion of gastrin, it has been postulated that treatment with PPIs could increase the risk of cancer, especially in Barrett's esophagus, gastric carcinoids, and colorectal cancer (CRC). Some tumors produce gastrin of their own, which can act in an autocrine manner to promote tumor growth. In addition, gastrin is known to foster the tumor microenvironment. However, in spite of these potentially increased cancer risks due to PPI-induced hypergastrinemia, prospective, large-scale cohort studies did not show an increase in CRC prevalence. The question as to why the long-term use of PPIs was not associated with an increased cancer risk of CRC might be answered by the fact that the PPIs antagonized the trophic effects of hypergastrinemia. Furthermore, the blockade of proton pumps or potassium channels in cancer cells could limit the abnormal glycolytic energy metabolism of cancer cells. Apart from their suppressive effect on gastric acids, PPIs exert an anti-tumor effect through the selective induction of apoptosis as well as an anti-inflammatory effect, and they protect cells from developing chemo- or radiotherapeutic resistance. Moreover, the anti-carcinogenic actions of PPIs were augmented with PPI-induced hypergastrinemia. Together with their potential targeted killing of cancer stem cells, these effects demonstrate their potential anti-cancer actions.

  4. Vesicle Photonics

    Science.gov (United States)

    Vasdekis, A. E.; Scott, E. A.; Roke, S.; Hubbell, J. A.; Psaltis, D.

    2013-07-01

    Amphiphiles, under appropriate conditions, can self-assemble into nanoscale thin membrane vessels (vesicles) that encapsulate and hence protect and transport molecular payloads. Vesicles assemble naturally within cells but can also be artificially synthesized. In this article, we review the mechanisms and applications of light-field interactions with vesicles. By being associated with light-emitting entities (e.g., dyes, fluorescent proteins, or quantum dots), vesicles can act as imaging agents in addition to cargo carriers. Vesicles can also be optically probed on the basis of their nonlinear response, typically from the vesicle membrane. Light fields can be employed to transport vesicles by using optical tweezers (photon momentum) or can directly perturb the stability of vesicles and hence trigger the delivery of the encapsulated payload (photon energy). We conclude with emerging vesicle applications in biology and photochemical microreactors.

  5. Are higher doses of proton pump inhibitors better in acute peptic bleeding?

    Directory of Open Access Journals (Sweden)

    Alejandro Villalón

    2016-06-01

    Full Text Available Si bien existe consenso acerca de la utilidad de los inhibidores de la bomba de protones en la hemorragia digestiva péptica aguda, persiste la controversia sobre cuál es la dosis óptima. Utilizando la base de datos Epistemonikos, la cual es mantenida mediante búsquedas en 30 bases de datos, identificamos seis revisiones sistemáticas que en conjunto incluyen 27 estudios aleatorizados evaluando esta pregunta. Realizamos un metanálisis y tablas de resumen de los resultados utilizando el método GRADE. Concluimos que las dosis altas de inhibidores de la bomba de protones probablemente resultan en poca o nula diferencia en el riesgo de resangrado y mortalidad. El balance riesgo/beneficio y costo/beneficio son probablemente desfavorables a la utilización de dosis altas.

  6. Oral versus intravenous proton pump inhibitors in preventing re-bleeding for patients with peptic ulcer bleeding after successful endoscopic therapy

    Directory of Open Access Journals (Sweden)

    Yen Hsu-Heng

    2012-06-01

    Full Text Available Abstract Background High dose intravenous proton pump inhibitor after endoscopic therapy for peptic ulcer bleeding has been recommended as adjuvant therapy. Whether oral proton pump inhibitor can replace intravenous proton pump inhibitor in this setting is unknown. This study aims to compare the clinical efficacy of oral and intravenous proton pump inhibitor after endoscopic therapy. Methods Patients with high-risk bleeding peptic ulcers after successful endoscopic therapy were randomly assigned as oral lansoprazole or intravenous esomeprazole group. Primary outcome of the study was re-bleeding rate within 14 days. Secondary outcome included hospital stay, volume of blood transfusion, surgical intervention and mortality within 1 month. Results From April 2010 to Feb 2011, 100 patients were enrolled in this study. The re-bleeding rates were 4% (2/50 in the intravenous group and 4% (2/50 in the oral group. There was no difference between the two groups with regards to the hospital stay, volume of blood transfusion, surgery or mortality rate. The mean duration of hospital stay was 1.8 days in the oral lansoprazole group and 3.9 days in the intravenous esomeprazole group (p > 0.01. Conclusion Patients receiving oral proton pump inhibitor have a shorter hospital stay. There is no evidence of a difference in clinical outcomes between oral and intravenous PPI treatment. However, the study was not powered to prove equivalence or non-inferiority. Future studies are still needed. Trial registration NCT01123031

  7. Effective pumping proton collection facilitated by a copper site (CuB) of bovine heart cytochrome c oxidase, revealed by a newly developed time-resolved infrared system.

    Science.gov (United States)

    Kubo, Minoru; Nakashima, Satoru; Yamaguchi, Satoru; Ogura, Takashi; Mochizuki, Masao; Kang, Jiyoung; Tateno, Masaru; Shinzawa-Itoh, Kyoko; Kato, Koji; Yoshikawa, Shinya

    2013-10-18

    X-ray structural and mutational analyses have shown that bovine heart cytochrome c oxidase (CcO) pumps protons electrostatically through a hydrogen bond network using net positive charges created upon oxidation of a heme iron (located near the hydrogen bond network) for O2 reduction. Pumping protons are transferred by mobile water molecules from the negative side of the mitochondrial inner membrane through a water channel into the hydrogen bond network. For blockage of spontaneous proton back-leak, the water channel is closed upon O2 binding to the second heme (heme a3) after complete collection of the pumping protons in the hydrogen bond network. For elucidation of the structural bases for the mechanism of the proton collection and timely closure of the water channel, conformational dynamics after photolysis of CO (an O2 analog)-bound CcO was examined using a newly developed time-resolved infrared system feasible for accurate detection of a single C=O stretch band of α-helices of CcO in H2O medium. The present results indicate that migration of CO from heme a3 to CuB in the O2 reduction site induces an intermediate state in which a bulge conformation at Ser-382 in a transmembrane helix is eliminated to open the water channel. The structural changes suggest that, using a conformational relay system, including CuB, O2, heme a3, and two helix turns extending to Ser-382, CuB induces the conformational changes of the water channel that stimulate the proton collection, and senses complete proton loading into the hydrogen bond network to trigger the timely channel closure by O2 transfer from CuB to heme a3.

  8. Effective Pumping Proton Collection Facilitated by a Copper Site (CuB) of Bovine Heart Cytochrome c Oxidase, Revealed by a Newly Developed Time-resolved Infrared System*

    Science.gov (United States)

    Kubo, Minoru; Nakashima, Satoru; Yamaguchi, Satoru; Ogura, Takashi; Mochizuki, Masao; Kang, Jiyoung; Tateno, Masaru; Shinzawa-Itoh, Kyoko; Kato, Koji; Yoshikawa, Shinya

    2013-01-01

    X-ray structural and mutational analyses have shown that bovine heart cytochrome c oxidase (CcO) pumps protons electrostatically through a hydrogen bond network using net positive charges created upon oxidation of a heme iron (located near the hydrogen bond network) for O2 reduction. Pumping protons are transferred by mobile water molecules from the negative side of the mitochondrial inner membrane through a water channel into the hydrogen bond network. For blockage of spontaneous proton back-leak, the water channel is closed upon O2 binding to the second heme (heme a3) after complete collection of the pumping protons in the hydrogen bond network. For elucidation of the structural bases for the mechanism of the proton collection and timely closure of the water channel, conformational dynamics after photolysis of CO (an O2 analog)-bound CcO was examined using a newly developed time-resolved infrared system feasible for accurate detection of a single C=O stretch band of α-helices of CcO in H2O medium. The present results indicate that migration of CO from heme a3 to CuB in the O2 reduction site induces an intermediate state in which a bulge conformation at Ser-382 in a transmembrane helix is eliminated to open the water channel. The structural changes suggest that, using a conformational relay system, including CuB, O2, heme a3, and two helix turns extending to Ser-382, CuB induces the conformational changes of the water channel that stimulate the proton collection, and senses complete proton loading into the hydrogen bond network to trigger the timely channel closure by O2 transfer from CuB to heme a3. PMID:23996000

  9. Renal intercalated cells are rather energized by a proton than a sodium pump.

    Science.gov (United States)

    Chambrey, Régine; Kurth, Ingo; Peti-Peterdi, Janos; Houillier, Pascal; Purkerson, Jeffrey M; Leviel, Françoise; Hentschke, Moritz; Zdebik, Anselm A; Schwartz, George J; Hübner, Christian A; Eladari, Dominique

    2013-05-07

    The Na(+) concentration of the intracellular milieu is very low compared with the extracellular medium. Transport of Na(+) along this gradient is used to fuel secondary transport of many solutes, and thus plays a major role for most cell functions including the control of cell volume and resting membrane potential. Because of a continuous leak, Na(+) has to be permanently removed from the intracellular milieu, a process that is thought to be exclusively mediated by the Na(+)/K(+)-ATPase in animal cells. Here, we show that intercalated cells of the mouse kidney are an exception to this general rule. By an approach combining two-photon imaging of isolated renal tubules, physiological studies, and genetically engineered animals, we demonstrate that inhibition of the H(+) vacuolar-type ATPase (V-ATPase) caused drastic cell swelling and depolarization, and also inhibited the NaCl absorption pathway that we recently discovered in intercalated cells. In contrast, pharmacological blockade of the Na(+)/K(+)-ATPase had no effects. Basolateral NaCl exit from β-intercalated cells was independent of the Na(+)/K(+)-ATPase but critically relied on the presence of the basolateral ion transporter anion exchanger 4. We conclude that not all animal cells critically rely on the sodium pump as the unique bioenergizer, but can be replaced by the H(+) V-ATPase in renal intercalated cells. This concept is likely to apply to other animal cell types characterized by plasma membrane expression of the H(+) V-ATPase.

  10. Proton pump inhibitor use and risk of adverse cardiovascular events in aspirin treated patients with first time myocardial infarction: nationwide propensity score matched study

    DEFF Research Database (Denmark)

    Charlot, Mette; Grove, Erik; Hansen, Peter Riis

    2011-01-01

    OBJECTIVE: To examine the effect of proton pump inhibitors on adverse cardiovascular events in aspirin treated patients with first time myocardial infarction. DESIGN: Retrospective nationwide propensity score matched study based on administrative data. Setting All hospitals in Denmark. PARTICIPANTS......: All aspirin treated patients surviving 30 days after a first myocardial infarction from 1997 to 2006, with follow-up for one year. Patients treated with clopidogrel were excluded. MAIN OUTCOME MEASURES: The risk of the combined end point of cardiovascular death, myocardial infarction, or stroke...... associated with use of proton pump inhibitors was analysed using Kaplan-Meier analysis, Cox proportional hazard models, and propensity score matched Cox proportional hazard models. Results 3366 of 19,925 (16.9%) aspirin treated patients experienced recurrent myocardial infarction, stroke, or cardiovascular...

  11. Two-week treatment with proton pump inhibitor is sufficient for healing post endoscopic submucosal dissection ulcers

    Science.gov (United States)

    Arai, Makoto; Matsumura, Tomoaki; Okimoto, Kenichiro; Oyamada, Arata; Saito, Keiko; Minemura, Shoko; Maruoka, Daisuke; Tanaka, Takeshi; Nakagawa, Tomoo; Katsuno, Tatsuro; Yokosuka, Osamu

    2014-01-01

    AIM: To investigate the optimum period of treatment for post endoscopic submucosal dissection (ESD) ulcers. METHODS: Patients who underwent ESD for gastric cancer were randomized to two groups and treated with esomeprazole 20 mg per day for 4 wk (4W group) or 2 wk (2W group). At 4 wk after ESD, we measured the size of the artificial ulcers by endoscopy and determined the ulcer healing rate, compared with the size of the ESD specimens. This randomized controlled trial study was approved by our ethics committee and registered in the UMIN Clinical Trial Registry. RESULTS: A total of 60 consecutive patients were included in the study. All patients received rebamipide 300 mg per day for 4 wk. One patient in 2W group who showed bleeding within two weeks and received endoscopic treatment was excluded from further analysis. The numbers of patients with ulcers in the healing/scar stage in the 2W and 4W groups at 4 wk after ESD were 20/6 and 28/5, respectively, with no significant difference. The ulcer healing rate in the 2W and 4W groups were 96.1% [95% confidence interval (CI): 94.6%-97.55] vs 94.8% (95%CI: 92.6%-97.1%), respectively, with no statistical difference (UMIN000006951). CONCLUSION: Two-wk treatment with a proton pump inhibitor is as effective as four-week treatment for healing post ESD ulcers. PMID:25473190

  12. CYP2C19 Phenoconversion by Routinely Prescribed Proton Pump Inhibitors Omeprazole and Esomeprazole: Clinical Implications for Personalized Medicine.

    Science.gov (United States)

    Klieber, Martin; Oberacher, Herbert; Hofstaetter, Silvia; Beer, Beate; Neururer, Martin; Amann, Anton; Alber, Hannes; Modak, Anil

    2015-09-01

    The phenotype pantoprazole-(13)C breath test (Ptz-BT) was used to evaluate the extent of phenoconversion of CYP2C19 enzyme activity caused by commonly prescribed proton pump inhibitors (PPI) omeprazole and esomprazole. The Ptz-BT was administered to 26 healthy volunteers and 8 stable cardiovascular patients twice at baseline and after 28 days of PPI therapy to evaluate reproducibility of the Ptz-BT and changes in CYP2C19 enzyme activity (phenoconversion) after PPI therapy. The average intrapatient interday variability in CYP2C19 phenotype (n = 31) determined by Ptz-BT was considerably low (coefficient of variation, 17%). Phenotype conversion resulted in 25 of 26 (96%) nonpoor metabolizer (non-PM) volunteers/patients as measured by the Ptz-BT at baseline and after PPI therapy. The incidence of PM status by phenotype following administration of omeprazole/esomeprazole (known inhibitors of CYP2C19) was 10-fold higher than those who are genetically PMs in the general population, which could have critical clinical implications for personalizing medications primarily metabolized by CYP2C19, such as clopidogrel, PPI, cyclophosphamide, thalidomide, citalopram, clonazepam, diazepam, phenytoin, etc. The Ptz-BT can rapidly (30 minutes) evaluate CYP2C19 phenotype and, more importantly, can identify patients with phenoconversion in CYP2C19 enzyme activity caused by nongenetic factors such as concomitant drugs. Copyright © 2015 by The American Society for Pharmacology and Experimental Therapeutics.

  13. A Case of Pantoprazole Anaphylaxis with Cross Reactivity to All Proton Pump Inhibitors: Finding a Safe Alternative.

    Science.gov (United States)

    Turedi, Ozlem; Sozener, Zeynep Celebi; Kendirlinan, Resat; Bavbek, Sevim

    2017-01-01

    Hypersensitivity reactions due to Proton pump inhibitors (PPIs ) are rare, and further anaphylaxis to a PPI with cross-reactivity to all commercially available PPIs is very rare. To present a case of anaphylaxis to pantoprazole with cross-reactivity to all commercially available PPIs. Skin prick tests (SPTs), intradermal tests (IDTs) and oral provocation tests (OPTs) were performed with available PPIs according to the method described in previous studies. All tested PPIs except lansoprazole were positive on skin tests either SPT or IDT. The patient was challenged with lansoprazole at increasing doses (7.5 mg, 15 mg, 30 mg capsule) every 60 minutes and she reacted with urticaria to 52.5 mg cumulative dose of lansoprazole. She could tolerate ranitidine and famotidine tablets via OPT. In our best knowledge, our case was the first case in this regard and that points the possibility of all cross-reactive pattern in patients with pantoprazole anaphylaxis and the importance of a thorough drug allergy work-up for finding safe alternatives. H2 receptor antagonists are used as safe alternatives in cases with PPI hypersensitivity. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  14. Analysis, occurrence, fate and risks of proton pump inhibitors, their metabolites and transformation products in aquatic environment: A review.

    Science.gov (United States)

    Kosma, Christina I; Lambropoulou, Dimitra A; Albanis, Triantafyllos A

    2016-11-01

    Proton pump inhibitors (PPIs) which include omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole, are extensively used for the relief of gastro-intestinal disorders. Despite their high worldwide consumption, PPIs are extensively metabolized in human bodies and therefore are not regularly detected in monitoring studies. Very recently, however, it has been shown that some omeprazole metabolites may enter and are likely to persist in aquatic environment. Hence, to fully assess the environmental exposures and risks associated with PPIs, it is important to better understand and evaluate the fate and behavior not only of the parent compound but also of their metabolites and their transformation products arising from biotic and abiotic processes (hydrolysis, photodegradation, biodegradation etc.) in the environment. In this light, the purpose of this review is to summarize the present state of knowledge on the introduction and behavior of these chemicals in natural and engineering systems and highlight research needs and gaps. It draws attention to their transformation, the increase contamination by their metabolites/TPs in different environmental matrices and their potential adverse effects in the environment. Furthermore, existing research on analytical developments with respect to sample treatment, separation and detection of PPIs and their metabolites/TPs is provided. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Clopidogrel and proton pump inhibitor (PPI) interaction: separate intake and a non-omeprazole PPI the solution?

    Science.gov (United States)

    2010-01-01

    Background Dual therapy with aspirin and clopidogrel increases the risk of gastrointestinal bleeding. Therefore, co-therapy with a proton pump inhibitor (PPI) is recommended by most guidelines. However, there are warnings against combining PPIs with clopidogrel because of their interactions with cytochrome P450 isoenzyme 2C19 (CYP2C19). Methods The effects of the combined or separate intake of 20 mg of omeprazole and 75 mg of clopidogrel on the clopidogrel-induced inhibition of platelet aggregation were measured in four healthy subjects whose CYP2C19 exon sequences were determined. The effects of co-therapy with 10 mg of rabeprazole were also examined. Results Two subjects showed the wild-type CYP2C19 sequence. The concurrent intake of omeprazole had no effect on clopidogrel-induced platelet inhibition in these subjects. Two subjects were heterozygous for the *2 allele, with predicted reduced CYP2C19 activity. One of them was a clopidogrel non-responder. In the second heterozygous subject, omeprazole co-therapy reduced the clopidogrel anti-platelet effect when taken simultaneously or separately. However, the simultaneous intake of rabeprazole did not reduce the clopidogrel effect. Conclusion The clopidogrel-PPI interaction does not seem to be a PPI class effect. Rabeprazole did not affect the clopidogrel effect in a subject with a clear omeprazole-clopidogrel interaction. The separate intake of PPI and clopidogrel may not be sufficient to prevent their interaction. PMID:20562062

  16. Chronic proton pump inhibition therapy in the diagnostic accuracy of serum pepsinogen I and gastrin concentrations to identify pernicious anaemia.

    Science.gov (United States)

    Martín-Alcolea, Mariam; Rodríguez-Hernández, Inés; Aldea, Marta; Rosas, Irene; Juncà, Jordi; Granada, Maria Luisa

    2017-06-01

    Chronic use of proton pump inhibitors (PPIs) leads to increases in gastrin and pepsinogen-I serum concentrations. To asses if chronic treatment with PPIs has an effect on serum gastrin and pepsinogen-I concentrations for the diagnosis of pernicious anaemia (PA). Serum gastrin and pepsinogen-I were measured in 38 patients with PA and 74 without PA (controls); 17/38 PA patients and 36/74 controls were treated with PPIs. Receiver Operating Curves (ROC) were used to compare diagnostic accuracy of gastrin and pepsinogen-I for PA in patients under chronic treatment with PPIs and in untreated patients. PPI treatment increased pepsinogen-I in patients and in controls, while gastrin increased only in controls. In untreated patients, a pepsinogen-I gastrin >115pg/mL had 100% sensitivity and 92.11% specificity for PA diagnosis. In PPI-treated patients, a pepsinogen Igastrin, 610pg/mL, had a very low sensitivity (58%). PPI chronic treatment decreased the diagnostic accuracy for the studied biomarkers, particularly of gastrin. In PPI-treated patients, serum pepsinogen-I concentrations >24.1ng/mL allowed rejecting a PA diagnosis with 100% specificity. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  17. Drug-Induced Vitamin B12 Deficiency: A Focus on Proton Pump Inhibitors and Histamine-2 Antagonists.

    Science.gov (United States)

    Linder, Lauren; Tamboue, Cynthia; Clements, Jennifer N

    2017-12-01

    To review primary literature of gastric acid suppressive agents and vitamin B12 deficiency. From the published articles, proton pump inhibitors (PPIs) are associated with a higher risk of inducing vitamin B12 deficiency than histamine-2 receptor antagonists (H2RAs). Literature suggests that there is an increased risk of developing vitamin B12 deficiency in patients who are exposed to extended durations of therapy with PPIs. There are, however, some conflicting data in elderly patients suggesting that the PPI use for more than 3 years does not increase the risk of vitamin B12 deficiency. No evidence was found to support the extended use of H2RA monotherapy causing vitamin B12 deficiency. The inconsistency of results reported could be due to the differing patient populations studied, such as Zollinger-Ellison syndrome (ZES) and elderly patients. Overall, the lack of consistent evidence shows the need for more research in this area. To investigate the clinical significance of vitamin B12 deficiency caused by acid suppression with PPIs and H2RAs, longer prospective studies are needed. These studies should focus on patient-centered outcomes to accurately determine the extended usage of PPI and H2RA and the true effects on vitamin B12 deficiency.

  18. Cytotoxic effects of the proton pump inhibitor omeprazole on the non-target marine microalga Tetraselmis suecica.

    Science.gov (United States)

    Seoane, Marta; Esperanza, Marta; Cid, Ángeles

    2017-10-01

    Omeprazole (OMP) is one of the most commonly used drugs for the treatment of gastro-intestinal disorders. Although it is daily consumed in high quantities and commonly detected in waters worldwide, relatively little is known about its ecotoxicity. The aim of this study was to evaluate the potential acute toxicity of increasing concentrations of OMP on the marine microalga Tetraselmis suecica analysing several cytotoxicity biomarkers by flow cytometry after 24h of exposure. Results showed that OMP caused a decrease in growth and autofluorescence, an increase in cellular volume and intracellular complexity, hyperpolarization of cytoplasmic and mitochondrial membranes and intracellular acidification. In addition, large amounts of reactive oxygen species (ROS) were generated which resulted in a decrease in the percentage of the viable population. However, the viable population showed an increase in their metabolic activity as an early response to overcome the stress. In conclusion, OMP may affect proton pumps in non-target organisms such as microalgae; it disturbed pH homeostasis and provoked an early accumulation of ROS that resulted in a rapid cell death in cells exposed to the highest concentration assayed. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Association between proton pump inhibitor therapy and clostridium difficile infection: a contemporary systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Imad M Tleyjeh

    Full Text Available INTRODUCTION: Emerging epidemiological evidence suggests that proton pump inhibitor (PPI acid-suppression therapy is associated with an increased risk of Clostridium difficile infection (CDI. METHODS: Ovid MEDLINE, EMBASE, ISI Web of Science, and Scopus were searched from 1990 to January 2012 for analytical studies that reported an adjusted effect estimate of the association between PPI use and CDI. We performed random-effect meta-analyses. We used the GRADE framework to interpret the findings. RESULTS: We identified 47 eligible citations (37 case-control and 14 cohort studies with corresponding 51 effect estimates. The pooled OR was 1.65, 95% CI (1.47, 1.85, I(2 = 89.9%, with evidence of publication bias suggested by a contour funnel plot. A novel regression based method was used to adjust for publication bias and resulted in an adjusted pooled OR of 1.51 (95% CI, 1.26-1.83. In a speculative analysis that assumes that this association is based on causality, and based on published baseline CDI incidence, the risk of CDI would be very low in the general population taking PPIs with an estimated NNH of 3925 at 1 year. CONCLUSIONS: In this rigorously conducted systemic review and meta-analysis, we found very low quality evidence (GRADE class for an association between PPI use and CDI that does not support a cause-effect relationship.

  20. Proton Pump Inhibitors and the Risk for Fracture at Specific Sites: Data Mining of the FDA Adverse Event Reporting System.

    Science.gov (United States)

    Wang, Liwei; Li, Mei; Cao, Yuying; Han, Zhengqi; Wang, Xueju; Atkinson, Elizabeth J; Liu, Hongfang; Amin, Shreyasee

    2017-07-17

    Proton pump inhibitors (PPIs) are widely used to treat gastric acid-related disorders. Concerns have been raised about potential fracture risk, especially at the hip, spine and wrist. However, fracture risk at other bone sites has not been as well studied. We investigated the association between PPIs and specific fracture sites using an aggregated knowledge-enhanced database, the Food and Drug Administration Adverse Event Reporting System Data Mining Set (AERS-DM). Proportional reporting ratio (PRR) was used to detect statistically significant associations (signals) between PPIs and fractures. We analyzed both high level terms (HLT) and preferred terms (PT) for fracture sites, defined by MedDRA (Medical Dictionary for Regulatory Activities). Of PPI users reporting fractures, the mean age was 65.3 years and the female to male ratio was 3.4:1. Results revealed signals at multiple HLT and PT fracture sites, consistent for both sexes. These included fracture sites with predominant trabecular bone, not previously reported as being associated with PPIs, such as 'rib fractures', where signals were detected for overall PPIs as well as for each of 5 generic ingredients (insufficient data for dexlansoprazole). Based on data mining from AERS-DM, PPI use appears to be associated with an increased risk for fractures at multiple sites.

  1. Effect of proton pump inhibitors on the serum concentrations of the selective serotonin reuptake inhibitors citalopram, escitalopram, and sertraline.

    Science.gov (United States)

    Gjestad, Caroline; Westin, Andreas A; Skogvoll, Eirik; Spigset, Olav

    2015-02-01

    The selective serotonin reuptake inhibitors (SSRIs) citalopram, escitalopram, and sertraline are all metabolized by the cytochrome P-450 isoenzyme CYP2C19, which is inhibited by the proton pump inhibitors (PPIs) omeprazole, esomeprazole, lansoprazole, and pantoprazole. The aim of the present study was to evaluate the effect of these PPIs on the serum concentrations of citalopram, escitalopram, and sertraline. Serum concentrations from patients treated with citalopram, escitalopram, or sertraline were obtained from a routine therapeutic drug monitoring database, and samples from subjects concomitantly using PPIs were identified. Dose-adjusted SSRI serum concentrations were calculated to compare data from those treated and those not treated with PPIs. Citalopram concentrations were significantly higher in patients treated with omeprazole (+35.3%; P Escitalopram concentrations were significantly higher in patients treated with omeprazole (+93.9%; P escitalopram is affected to a greater extent than are citalopram and sertraline. When omeprazole or esomeprazole are used in combination with escitalopram, a 50% dose reduction of the latter should be considered.

  2. Proton pump inhibitors protect mice from acute systemic inflammation and induce long-term cross-tolerance.

    Science.gov (United States)

    Balza, E; Piccioli, P; Carta, S; Lavieri, R; Gattorno, M; Semino, C; Castellani, P; Rubartelli, A

    2016-07-21

    Incidence of sepsis is increasing, representing a tremendous burden for health-care systems. Death in acute sepsis is attributed to hyperinflammatory responses, but the underlying mechanisms are still unclear. We report here that proton pump inhibitors (PPIs), which block gastric acid secretion, selectively inhibited tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) secretion by Toll-like receptor (TLR)-activated human monocytes in vitro, in the absence of toxic effects. Remarkably, the oversecretion of IL-1β that represents a hallmark of monocytes from patients affected by cryopyrin-associated periodic syndrome is also blocked. Based on these propaedeutic experiments, we tested the effects of high doses of PPIs in vivo in the mouse model of endotoxic shock. Our data show that a single administration of PPI protected mice from death (60% survival versus 5% of untreated mice) and decreased TNF-α and IL-1β systemic production. PPIs were efficacious even when administered after lipopolysaccharide (LPS) injection. PPI-treated mice that survived developed a long-term cross-tolerance, becoming resistant to LPS- and zymosan-induced sepsis. In vitro, their macrophages displayed impaired TNF-α and IL-1β to different TLR ligands. PPIs also prevented sodium thioglycollate-induced peritoneal inflammation, indicating their efficacy also in a non-infectious setting independent of TLR stimulation. Lack of toxicity and therapeutic effectiveness make PPIs promising new drugs against sepsis and other severe inflammatory conditions.

  3. Lactobacillus paracasei F19 versus placebo for the prevention of proton pump inhibitor-induced bowel symptoms: a randomized clinical trial.

    Science.gov (United States)

    Compare, Debora; Rocco, Alba; Sgamato, Costantino; Coccoli, Pietro; Campo, Salvatore Maria Antonio; Nazionale, Immacolata; Larussa, Tiziana; Luzza, Francesco; Chiodini, Paolo; Nardone, Gerardo

    2015-04-01

    Proton pump inhibitors may foster intestinal dysbiosis and related bowel symptoms. To evaluate the effect of Lactobacillus paracasei F19 on bowel symptom onset in patients on long-term proton pump inhibitors. In this randomized, double-blind, placebo-controlled study, patients with typical gastroesophageal reflux disease symptoms receiving pantoprazole 40 mg/d for six months were randomly assigned to receive: (A) Lactobacillus paracasei F19 bid for three days/week for six months; (B) placebo bid for three days/week for six months; (C) Lactobacillus paracasei F19 bid for three days/week for three months and placebo bid for three days/week for the following three months; (D) placebo bid for three days/week for three months and Lactobacillus paracasei F19 bid for three days/week for the following three months. Bloating, flatulence, abdominal pain and bowel habit were assessed monthly. 100/312 patients were enrolled. In the parallel groups, the treatment-by-time interaction affected bloating (p = 0.015), while Lactobacillus paracasei F19 treatment alone affected flatulence (p = 0.011). Moreover, the treatment-by-time interaction significantly affected the mean score of bloating (p = 0.01) and flatulence (p Lactobacillus paracasei F19 supplementation prevents bowel symptom onset in patients on long-term proton pump inhibitors. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  4. The influence of osmotic stress on the content of calcium ions in the red beet vacuoles and on the transport activity of tonoplast proton pumps

    Directory of Open Access Journals (Sweden)

    Ozolina N.V.

    2012-05-01

    Full Text Available The contents of calcium ions in the isolated vacuoles and in intact red beets under the conditions of dormancy and osmotic stress was determined. It is demonstrated that the content of calcium ions in the red beet vacuoles not exposed to osmotic stress makes 13.3% of the total content these ions in intact red beets. Under the conditions of osmotic stress, this indicator increases substantially. Furthermore, under the conditions of hyperosmotic stress, the content of calcium ions in the vacuoles was 30%, while under hypoosmotic stress it was 49% of the total content of these ions in the intact red beet. The transition of calcium ions from the cytoplasm and other compartments into the vacuole under the conditions of osmotic stress is, probably, one of forms of participation of the vacuole in adaptation processes of the plant cell under this kind of abiotic stress. It has been demonstrated for the first time that tonoplast proton pumps, which actively participate in provision of calcium homeostasis in cytoplasm, substantially activate their transport activity under osmotic stress, what allows one to speak about their important role in the cell’s protective programs. Under normal (no stress conditions, artificial elevation of the content of calcium ions led to inhibition of activity of the tonoplast proton pumps, while under gipoosmotic stress the activity of tonoplast proton pumps increased, what might aid to restoring homeoctasis with respect to calcium ions in cytoplasm.

  5. Inadequate prescription of chronic consumption of proton pump inhibitors in a hospital in Mexico: Cross-sectional study

    Directory of Open Access Journals (Sweden)

    Jaime Alberto Sánchez-Cuén

    2013-03-01

    Full Text Available Introduction: PPIs have been an enormous therapeutic advance in acid-related diseases. However, it has been detected an abuse in its consumption. The aim of this study was to determine the frequency of inadequate prescription of chronic use of PPIs in outpatients in a speciality hospital. Material and methods: we performed a cross-sectional descriptive study review. The study population were patients, chronic users of proton pump inhibitors (PPIs, attending outpatient consult in a hospital of government workers. We defined as chronic user of PPIs that patient that takes medication daily for over a year and inappropriate prescription, that one that has not been approved by the clinical guidelines. A simple random sampling was utilized. The following parameters were investigated: diagnosis and prescription of PPIs, time of use, at which level of care PPIs were prescribed (primary care or specialist, self-medication, with or without endoscopy. For the statistical analysis, we used Student's t-test and Chi-square, 95% confidence intervals and significance 0.05 %. Results: we reviewed 153 patients, 40 (26.1 % men and 113 (73.9 % women, mean age 58 ± 11.4 years. The prescription of chronic treatment with PPIs was adequate in 64.7 % of patients and inadequate in 35.3 %. The most common appropriate prescription (31.3 % of chronic use of PPIs was due to gastroesophageal reflux disease. The most common inadequate prescription was absence of diagnosis (22.2 %, polypharmacy without nonsteroidal antiinflammatory drugs (16.6 % and chronic gastritis (16.6 %. History of endoscopy were not statistically significant. Conclusions: the frequency of inappropriate prescriptions of chronic use of PPIs was high, around 35.3 %, similar to those reported in hospitals in developed countries.

  6. Analysis, occurrence, fate and risks of proton pump inhibitors, their metabolites and transformation products in aquatic environment: A review

    Energy Technology Data Exchange (ETDEWEB)

    Kosma, Christina I. [Department of Chemistry, University of Ioannina, Ioannina, 45110 (Greece); Lambropoulou, Dimitra A., E-mail: dlambro@chem.auth.gr [Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Albanis, Triantafyllos A. [Department of Chemistry, University of Ioannina, Ioannina, 45110 (Greece)

    2016-11-01

    Proton pump inhibitors (PPIs) which include omeprazole, esomeprazole, lansoprazole, pantoprazole and rabeprazole, are extensively used for the relief of gastro-intestinal disorders. Despite their high worldwide consumption, PPIs are extensively metabolized in human bodies and therefore are not regularly detected in monitoring studies. Very recently, however, it has been shown that some omeprazole metabolites may enter and are likely to persist in aquatic environment. Hence, to fully assess the environmental exposures and risks associated with PPIs, it is important to better understand and evaluate the fate and behavior not only of the parent compound but also of their metabolites and their transformation products arising from biotic and abiotic processes (hydrolysis, photodegradation, biodegradation etc.) in the environment. In this light, the purpose of this review is to summarize the present state of knowledge on the introduction and behavior of these chemicals in natural and engineering systems and highlight research needs and gaps. It draws attention to their transformation, the increase contamination by their metabolites/TPs in different environmental matrices and their potential adverse effects in the environment. Furthermore, existing research on analytical developments with respect to sample treatment, separation and detection of PPIs and their metabolites/TPs is provided. - Highlights: • Occurrence and fate of PPIs and their metabolites/TPs in the aquatic environment • Overview of the analytical methods applied, using LC-MS techniques • Omeprazole attended the most frequent analysis • Determination and behavior of omeprazole's metabolites/TPs in the environment • More ecotoxicological research is needed to assess the risks of PPIs.

  7. Acute Coronary Syndromes, Gastrointestinal Protection, and Recommendations Regarding Concomitant Administration of Proton-Pump Inhibitors (Omeprazol/Esomeprazole) and Clopidogrel.

    Science.gov (United States)

    Lozano, Iñigo; Sanchez-Insa, Esther; de Leiras, Sergio Rodríguez; Carrillo, Pilar; Ruiz-Quevedo, Valeriano; Pinar, Eduardo; Gopar-Gopar, Silvia; Bayon, Jeremías; Mañas, Pilar; Lasa, Garikoitz; CruzGonzalez, Ignacio; Hernandez, Felipe; Fernandez-Portales, Javier; Fernandez-Fernandez, Javier; Pérez-Serradilla, Ana; de la Torre Hernandez, José M; Gomez-Jaume, Alfredo

    2016-02-01

    The Food and Drug Administration and the European Medicines Agency sent a warning in 2010 discouraging the concomitant use of clopidogrel with omeprazole or esomeprazole. The purpose is to know the gastroprotective approach in patients with acute coronary syndrome (ACS) and the level of follow-up of the alert. In 17 hospitals with catheterization laboratory in Spain, 1 per region, we studied 25 consecutive patients per hospital whose diagnosis of discharge since October 1, 2013, had been any type of ACS. We analyzed their baseline clinical profile, the gatroprotective agents at admission and discharge and the antiplatelet therapy at discharge. The number of patients included was 425: age 67.2 ± 12.5 years, women 29.8%, diabetes 36.5%. The patients presented unstable angina in 21.6%, non-ST-elevation myocardial infarction in 35.3% and ST-elevation myocardial infarction in 43.1%. Conservative approach was chosen in 17.9%, bare-metal stents 32.2%, ≥ 1 drug-eluting stent 48.5%, and surgery 1.4%. Aspirin was indicated in 1.9%, aspirin + clopidogrel 73.6%, aspirin + prasugrel 17.6%, and aspririn + ticagrelor 6.8%. Gastroprotective agents were present in 40.2% patients at admission and this percentage increased to 93.7% at discharge. Of the 313 (73.6%) on clopidogrel in 96 (30.6%) was combined with omeprazole and 3 (0.95%) with esomeprazole, whereas the most commonly used was pantoprazole with 190 patients (44.7%). In conclusion, almost the totality of the patients with an ACS receive gastroprotective agents at the moment of discharge, most of them with proton-pump inhibitors. In one every 3 cases of the patients who are on clopidogrel, the recommendation of the Food and Drug Administration and the European Medicines Agency is not followed. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Systematic review: the effects of long-term proton pump inhibitor use on serum gastrin levels and gastric histology.

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    Lundell, L; Vieth, M; Gibson, F; Nagy, P; Kahrilas, P J

    2015-09-01

    Proton pump inhibitors (PPIs) have a well-established safety profile. However, concerns have been raised about a potential relationship between PPI-induced hypergastrinaemia and the development of enterochromaffin-like (ECL) cell hyperplasia, neuroendocrine tumours and gastric cancer during long-term therapy. To review the effects of long-term PPI use on serum gastrin levels and gastric histopathology. A systematic literature search was conducted in PubMed on 21 April 2015 to identify studies reporting the effects of long-term (defined as >3 years) PPI use on gastrin levels and gastric histopathology. A total of 16 studies (1920 patients) met the inclusion criteria. During long-term PPI therapy, mean gastrin levels rose to one to three times the upper limit of the normal range (~100 pg/mL), and an increased prevalence of ECL cell hyperplasia was observed (+7.8-52.0%). Helicobacter pylori-positive patients had a significantly increased risk of developing ECL linear/micronodular hyperplasia compared with H. pylori-negative patients [OR: 2.45 (95% CI: 1.47-4.10), P = 0.0006]; however, no evidence of neoplastic changes was found. The risk of corpus atrophy was markedly higher in H. pylori-positive patients than in H. pylori-negative patients [OR: 11.45 (95% CI: 6.25-20.99), P < 0.00001]. Not a single case of gastric adenocarcinoma was found. Long-term PPI therapy induced moderate hypergastrinaemia in most patients and an increased prevalence of ECL cell hyperplasia. H. pylori-positive patients receiving long-term PPI therapy were exposed to a higher risk of corpus atrophy than H. pylori-negative patients. No neuroendocrine tumours or gastric cancers were found. © 2015 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.

  9. Interaction Between Low-Dose Methotrexate and Nonsteroidal Anti-inflammatory Drugs, Penicillins, and Proton Pump Inhibitors.

    Science.gov (United States)

    Hall, Jill J; Bolina, Monika; Chatterley, Trish; Jamali, Fakhreddin

    2017-02-01

    To review the potential drug interactions between low-dose methotrexate (LD-MTX) and nonsteroidal anti-inflammatory drugs (NSAIDs), penicillins, and proton-pump inhibitors (PPIs) given the disparity between interactions reported for high-dose and low-dose MTX to help guide clinicians. A literature search was performed in MEDLINE (1946 to September 2016), EMBASE (1974 to September 2016), and International Pharmaceutical Abstracts (1970 to January 2015) to identify reports describing potential drug interactions between LD-MTX and NSAIDS, penicillins, or PPIs. Reference lists of included articles were reviewed to find additional eligible articles. All English-language observational, randomized, and pharmacokinetic (PK) studies assessing LD-MTX interactions in humans were analyzed to determine clinical relevance in making recommendations to clinicians. Clinical case reports were assigned a Drug Interaction Probability Scale score. A total of 32 articles were included (28 with NSAIDs, 3 with penicillins, and 2 with PPIs [1 including both PPI and NSAID]). Although there are some PK data to describe increased LD-MTX concentrations when NSAIDs are used concomitantly, the clinical relevance remains unclear. Based on the limited data on LD-MTX with penicillins and PPIs, no clinically meaningful interaction was identified. Given the available evidence, the clinical importance of the interaction between LD-MTX and NSAIDs, penicillins, and PPIs cannot be substantiated. Health care providers should assess the benefit and risk of LD-MTX regardless of concomitant drug use, including factors known to predispose patients to MTX toxicity, and continue to monitor clinical and laboratory parameters per guideline recommendations.

  10. Potential Mechanisms of Hematological Adverse Drug Reactions in Patients Receiving Clozapine in Combination With Proton Pump Inhibitors.

    Science.gov (United States)

    Wiciński, Michał; Węclewicz, Mateusz M; Miętkiewicz, Mateusz; Malinowski, Bartosz; Grześk, Elżbieta; Klonowska, Joanna

    2017-03-01

    Clozapine is a second-generation antipsychotic which has proven efficacy in treating the symptoms of schizophrenia. Although clozapine therapy is associated with a number of adverse drug reactions, it is frequently used. One of the most common adverse drug reactions is gastroesophageal reflux disease which is an indication for treatment with proton pump inhibitors (PPIs). Coadministration of clozapine and PPIs increases the risk of hematological adverse drug reactions, including neutropenia and agranulocytosis. The mechanism in idiosyncratic agranulocytosis is not dose related and involves either a direct toxic or an immune-allergic effect. It is suspected that the clozapine metabolites nitrenium ion and N-desmethylclozapine may cause apoptosis or impair growth of granulocytes. Formation of N-desmethylclozapine is correlated with activity of the cytochrome P450 enzymes 1A2 and 3A4 (CYP1A2 and CYP3A4). Nitrenium ion is produced by the flavin-containing monooxygenase system of leukocytes. A drug interaction between clozapine and a PPI is a consequence of the induction of common metabolic pathways either by the PPI or clozapine. Findings to date suggest that indirect induction of flavin-containing monooxygenase by omeprazole through the aryl hydrocarbon receptor increases the expression of the enzyme mRNA and in the long term may cause the increase in activity. Moreover, induction of CYP1A2, especially by omeprazole and lansoprazole, may increase the serum concentration of N-desmethylclozapine, which can accumulate in lymphocytes and may achieve toxic levels. Another hypothesis that may explain hematological adverse drug reactions is competitive inhibition of CYP2C19, which may contribute to increased serum concentrations of toxic metabolites.

  11. Acid suppression by proton pump inhibitors enhances aquaporin-4 and KCNQ1 expression in gastric fundic parietal cells in mouse.

    Science.gov (United States)

    Matsuzaki, Juntaro; Suzuki, Hidekazu; Minegishi, Yuriko; Sugai, Etsuko; Tsugawa, Hitoshi; Yasui, Masato; Hibi, Toshifumi

    2010-12-01

    The widespread use of proton pump inhibitors (PPIs) is known to cause sporadic gastric fundic gland polyps (FGPs). Altered expression and localization of the water or ion transport proteins might contribute to the excess fluid secretion into the cystic lumen for the development of FGPs. We investigated the alteration of the murine gastric fundic mucosa after PPI treatment, and examined the expression of water channel aquaporin-4 (AQP4) and potassium channel KCNQ1, which are expressed only in the parietal cells in the gastric mucosa. Male 5-week-old C57BL/6J mice were administered lansoprazole (LPZ) by subcutaneous injection for 8 weeks. The expression of AQP4 and KCNQ1 were investigated by Western blotting, quantitative RT-PCR, and immunohistochemistry. The expression of mucin-6 (Muc6), pepsinogen, and sonic hedgehog (Shh) were also investigated as mucosal cell lineage markers. Gastric mucosal hyperplasia with multiple cystic dilatations, exhibiting similar histological findings to the FGPs, was observed in the LPZ-treated mice. An increase in the number of AQP4-positive parietal cells and KCNQ1-positive parietal cells was observed. The extension of the distribution of AQP4-positive cells toward the surface of the fundic glands was also observed. The expression levels of AQP4 mRNA and protein were significantly enhanced. The expression of KCNQ1 mRNA was correlated with that of AQP4 mRNA in the LPZ-treated mice. Mucous neck-to-zymogenic cell lineage differentiation was delayed in association with decreased expression of Shh in the LPZ-treated mice. PPI administration increased the number of parietal cells with enhanced expression of AQP4 and KCNQ1.

  12. Use of Proton-Pump Inhibitors Predicts Heart Failure and Death in Patients with Coronary Artery Disease.

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    Ana María Pello Lázaro

    Full Text Available Proton-pump inhibitors (PPIs seem to increase the incidence of cardiovascular events in patients with coronary artery disease (CAD, mainly in those using clopidogrel. We analysed the impact of PPIs on the prognosis of patients with stable CAD.We followed 706 patients with CAD. Primary outcome was the combination of secondary outcomes. Secondary outcomes were 1 acute ischaemic events (any acute coronary syndrome, stroke, or transient ischaemic attack and 2 heart failure (HF or death.Patients on PPIs were older [62.0 (53.0-73.0 vs. 58.0 (50.0-70.0 years; p = 0.003] and had a more frequent history of stroke (4.9% vs. 1.1%; p = 0.004 than those from the non-PPI group, and presented no differences in any other clinical variable, including cardiovascular risk factors, ejection fraction, and therapy with aspirin and clopidogrel. Follow-up was 2.2±0.99 years. Seventy-eight patients met the primary outcome, 53 developed acute ischaemic events, and 33 HF or death. PPI use was an independent predictor of the primary outcome [hazard ratio (HR = 2.281 (1.244-4.183; p = 0.008], along with hypertension, body-mass index, glomerular filtration rate, atrial fibrillation, and nitrate use. PPI use was also an independent predictor of HF/death [HR = 5.713 (1.628-20.043; p = 0.007], but not of acute ischaemic events. A propensity score showed similar results.In patients with CAD, PPI use is independently associated with an increased incidence of HF and death but not with a high rate of acute ischaemic events. Further studies are needed to confirm these findings.

  13. Non-specific gastric inflammation in children is associated with proton pump inhibitor treatment for more than 6 weeks

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    Eduardo Daniel Rosas-Blum

    2014-01-01

    Full Text Available Background & Aims: Non-specific gastric inflammation (NSGI is a commonly reported pathological finding. We investigated if it is associated with the use of proton pump inhibitors (PPI in children at a single tertiary center. Methods: We performed an IRB-approved chart review of all endoscopy and biopsy reports of patients who underwent esophagogastroduodenoscopy between July 2009 to July 2010 (n=310. Demographic data, dose, and duration of exposure to PPI, and biopsy results were collected and analyzed. All esophageal, gastric and duodenal biopsies were independently reviewed by a pathologist. Patients with acute gastritis, moderate/severe chronic gastric inflammation or Helicobacter pylori infection were excluded. The presence of NSGI was compared between patients exposed and not exposed to PPI as well as between patients with different doses and durations of PPI exposure to assess for potential associations. Results: A total of 193 patients were included: 88 (46% had a history of PPI use, and 48 (25% were found to have NSGI. Compared to patients not exposed to PPI, the odds ratio of NSGI in patients exposed to PPIs was 2.81(95% CI: 1.36-5.93. The odds ratio of NSGI in patients exposed to PPI for >3 months was 4.53(95% CI: 1.69-11.97. Gender, ethnicity, and age were not associated with NSGI. No histological differences were found in the esophagus and duodenum between patients exposed and not exposed to PPI. Conclusion: This study found that PPI exposure is associated with NSGI with a higher risk for those exposed for >3 months. As the clinical implications of NSGI are not known, judicious use of PPIs is needed. Prospective studies are required to confirm and to determine the etiologic factors (i.e. alteration of the gastric pH, serum gastrin that may be related with the presence of NGSI.

  14. Effects of proton pump inhibitor on outcomes of patients with severe acute pancreatitis based on a national administrative database.

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    Murata, Atsuhiko; Ohtani, Makoto; Muramatsu, Keiji; Matsuda, Shinya

    2015-01-01

    This study aimed to investigate whether proton pump inhibitors (PPIs) affect the outcomes of patients with severe acute pancreatitis based on a national administrative database. A total of 10,400 patients with severe acute pancreatitis were referred to 1021 hospitals between 2010 and 2012 in Japan. Patients were divided into two groups: patients who used PPIs (n = 3879) and those without PPIs (n = 6521). We collected patients' data from the administrative database to compare in-hospital mortality within 7, 14, and 28 days, and overall in-hospital mortality between groups, using propensity score analysis to adjust for treatment selection bias. Multiple logistic regression showed that use of PPIs did not affect in-hospital mortality within 7 and 14 days. The odds ratio (OR) for mortality within 7 days was 1.14 (95% confidence interval [CI]: 0.91-1.42, p = 0.236) while that within 14 days was 1.10 (95% CI: 0.89-1.35, p = 0.349). No significant association was observed for in-hospital mortality within 28 days and overall in-hospital mortality (OR for within 28 days: 1.12, 95% CI: 0.92-1.37, p = 0.224; OR for overall in-hospital mortality: 1.42, 95% CI: 0.97-1.87, p = 0.065). This study shows that use of PPIs does not affect clinical outcomes of patients with severe acute pancreatitis. Prospective or randomized studies are needed to confirm the efficacy of PPIs on outcomes of patients with severe acute pancreatitis in the future. Copyright © 2015 IAP and EPC. Published by Elsevier B.V. All rights reserved.

  15. Construction, internal validation and implementation in a mobile application of a scoring system to predict nonadherence to proton pump inhibitors.

    Science.gov (United States)

    Mares-García, Emma; Palazón-Bru, Antonio; Folgado-de la Rosa, David Manuel; Pereira-Expósito, Avelino; Martínez-Martín, Álvaro; Cortés-Castell, Ernesto; Gil-Guillén, Vicente Francisco

    2017-01-01

    Other studies have assessed nonadherence to proton pump inhibitors (PPIs), but none has developed a screening test for its detection. To construct and internally validate a predictive model for nonadherence to PPIs. This prospective observational study with a one-month follow-up was carried out in 2013 in Spain, and included 302 patients with a prescription for PPIs. The primary variable was nonadherence to PPIs (pill count). Secondary variables were gender, age, antidepressants, type of PPI, non-guideline-recommended prescription (NGRP) of PPIs, and total number of drugs. With the secondary variables, a binary logistic regression model to predict nonadherence was constructed and adapted to a points system. The ROC curve, with its area (AUC), was calculated and the optimal cut-off point was established. The points system was internally validated through 1,000 bootstrap samples and implemented in a mobile application (Android). The points system had three prognostic variables: total number of drugs, NGRP of PPIs, and antidepressants. The AUC was 0.87 (95% CI [0.83-0.91], p < 0.001). The test yielded a sensitivity of 0.80 (95% CI [0.70-0.87]) and a specificity of 0.82 (95% CI [0.76-0.87]). The three parameters were very similar in the bootstrap validation. A points system to predict nonadherence to PPIs has been constructed, internally validated and implemented in a mobile application. Provided similar results are obtained in external validation studies, we will have a screening tool to detect nonadherence to PPIs.

  16. Maternal use of proton pump inhibitors during early pregnancy and the prevalence of hypospadias in male offspring.

    Science.gov (United States)

    Erichsen, Rune; Mikkelsen, Ellen; Pedersen, Lars; Sørensen, Henrik Toft

    2014-01-01

    Proton pump inhibitors (PPIs) are increasingly used in reflux disease treatment also among pregnant women. Hypospadias prevalence is increasing and the birth defect is diagnosed in 0.3%-0.8% of male births, but the association with maternal PPI use during pregnancy is virtually unknown. Therefore, we decided to estimate the hypospadias risk in male offspring after maternal PPI use during pregnancy. We used Danish nationwide registries to conduct a population-based prevalence study including all live-born boys from 1997 through 2009. Maternal PPI use was classified according to exposure time: early pregnancy (30 days before conception through the end of the first trimester) and entire pregnancy (30 days before and throughout pregnancy). Outcome was defined as a hospital hypospadias diagnosis recorded any time after delivery. We calculated prevalence ratios and 95% confidence intervals associating maternal PPI use with hypospadias in male offspring using Cox proportional hazard regression analysis and adjusted for confounding factors. We identified a total of 430,569 live-born boys of whom 2926 were exposed to maternal PPI use during early pregnancy. Among the exposed boys, 20 (0.7%) were diagnosed with hypospadias, whereas 2683 (0.6%) of the nonexposed had hypospadias (adjusted prevalence ratio = 1.1; 95% confidence interval, 0.7-1.7). A total of 5227 boys were exposed during the entire pregnancy, and 32 (0.6%) had hypospadias corresponding to a prevalence ratio of 1.0 (95% confidence interval, 0.7-1.4). The subanalysis restricted to omeprazole exposure showed similar results. We thus conclude that maternal PPI use during pregnancy was not associated with hypospadias in boy offspring.

  17. Analysis of the Interaction between Clopidogrel, Aspirin, and Proton Pump Inhibitors Using the FDA Adverse Event Reporting System Database.

    Science.gov (United States)

    Suzuki, Yukiya; Suzuki, Honami; Umetsu, Ryogo; Uranishi, Hiroaki; Abe, Junko; Nishibata, Yuri; Sekiya, Yasuaki; Miyamura, Nobuteru; Hara, Hideaki; Tsuchiya, Teruo; Kinosada, Yasutomi; Nakamura, Mitsuhiro

    2015-01-01

    Clopidogrel is an antiplatelet agent widely used in combination with aspirin to limit the occurrence of cardiovascular (embolic/thrombotic) events. Consensus guidelines recommend proton pump inhibitors (PPIs) as a gastrointestinal (GI) prophylactic measure for all patients receiving dual antiplatelet therapy with clopidogrel and aspirin. The objective of this study was to analyze the effect of the simultaneous use of clopidogrel, aspirin, and PPIs on hemorrhagic and embolic/thrombotic events using the U.S. Food and Drug Administration (FDA) Adverse Event Reporting System (FAERS) database. Reports of hemorrhagic and embolic/thrombotic events between 2004 and 2013 were analyzed with a reporting odds ratio (ROR) algorithm and logistic regression methods. The Medical Dictionary for Regulatory Activities Preferred Terms was used to identify such events. Regarding hemorrhagic events, the adjusted RORs of the concomitant use of aspirin and clopidogrel and those of PPIs prescribed with aspirin and clopidogrel were 4.40 (95% confidence interval [CI], 4.02-4.81) and 3.40 (95% CI, 2.84-4.06), respectively. For embolic/thrombotic events, the adjusted RORs of the concomitant use of aspirin and clopidogrel and those of PPIs prescribed with aspirin and clopidogrel were 2.37 (95% CI, 2.16-2.59) and 2.38 (95% CI, 2.00-2.84), respectively. Among patients included in the FAERS database, the concurrent use of aspirin and clopidogrel with PPIs reduced the adjusted ROR of GI hemorrhagic events. PPIs had little influence on the adjusted ROR of embolic/thrombotic events. These results support the use of PPIs as a preventive measure against GI hemorrhagic events for patients receiving clopidogrel and aspirin.

  18. Implementation of Global Strategies to Prevent Hospital-Onset Clostridium difficile Infection: Targeting Proton Pump Inhibitors and Probiotics.

    Science.gov (United States)

    Lewis, Paul O; Lundberg, Timothy S; Tharp, Jennifer L; Runnels, Clay W

    2017-10-01

    Proton pump inhibitors (PPIs) have been identified as a significant risk factor for the development of Clostridium difficile infection (CDI). Probiotics given concurrently with antibiotics have been shown to have a moderate impact on preventing CDI. To evaluate the effectiveness of hospital-wide interventions designed to reduce PPI use and increase probiotics and whether these interventions were associated with a change in the incidence of hospital onset (HO)-CDI. This retrospective cohort study compared 2 fiscal years: July 2013 to June 2014 (FY14) and July 2014 to June 2015 (FY15). In July of FY15, global educational initiatives were launched targeting PPIs. Additionally, a HO-CDI prevention bundle was added to antibiotic-containing order sets targeting probiotics. Overall PPI use, probiotic use, and incidence of HO-CDI were recorded and compared for each cohort. Charts were also reviewed for patients who developed HO-CDI for the presence and appropriateness of a PPI and presence of probiotics. The interventions resulted in a decrease in PPI use by 14% or 96 doses/1000 patient days (TPD; P = 0.0002) and a reduction in IV PPI use by 31% or 71 doses/TPD ( P = 0.0008). Probiotic use increased by 130% or 126 doses/TPD ( P = 0.0006). The incidence of HO-CDI decreased by 20% or 0.1 cases/TPD ( P = 0.04). A collaborative, multifaceted educational initiative directed at highlighting the risks associated with PPI use was effective in reducing PPI prescribing. The implementation of a probiotic bundle added to antibiotic order sets was effective in increasing probiotic use. These interventions were associated with a decrease in incidence of HO-CDI.

  19. Proton pump inhibitors and the risk of hospitalisation for community-acquired pneumonia: replicated cohort studies with meta-analysis

    Science.gov (United States)

    Filion, Kristian B; Chateau, Dan; Targownik, Laura E; Gershon, Andrea; Durand, Madeleine; Tamim, Hala; Teare, Gary F; Ravani, Pietro; Ernst, Pierre; Dormuth, Colin R

    2014-01-01

    Objective Previous observational studies suggest that the use of proton pump inhibitors (PPIs) may increase the risk of hospitalisation for community-acquired pneumonia (HCAP). However, the potential presence of confounding and protopathic biases limits the conclusions that can be drawn from these studies. Our objective was, therefore, to examine the risk of HCAP with PPIs prescribed prophylactically in new users of non-steroidal anti-inflammatory drugs (NSAIDs). Design We formed eight restricted cohorts of new users of NSAIDs, aged ≥40 years, using a common protocol in eight databases (Alberta, Saskatchewan, Manitoba, Ontario, Quebec, Nova Scotia, US MarketScan and the UK's General Practice Research Database (GPRD)). This specific patient population was studied to minimise bias due to unmeasured confounders. High-dimensional propensity scores were used to estimate site-specific adjusted ORs (aORs) for HCAP at 6 months in PPI patients compared with unexposed patients. Fixed-effects meta-analytic models were used to estimate overall effects across databases. Results Of the 4 238 504 new users of NSAIDs, 2.3% also started a PPI. The cumulative 6-month incidence of HCAP was 0.17% among patients prescribed PPIs and 0.12% in unexposed patients. After adjustment, PPIs were not associated with an increased risk of HCAP (aOR=1.05; 95% CI 0.89 to 1.25). Histamine-2 receptor antagonists yielded similar results (aOR=0.95, 95% CI  0.75 to 1.21). Conclusions Our study does not support the proposition of a pharmacological effect of gastric acid suppressors on the risk of HCAP. PMID:23856153

  20. Multi-indication Pharmacotherapeutic Multicriteria Decision Analytic Model for the Comparative Formulary Inclusion of Proton Pump Inhibitors in Qatar.

    Science.gov (United States)

    Al-Badriyeh, Daoud; Alabbadi, Ibrahim; Fahey, Michael; Al-Khal, Abdullatif; Zaidan, Manal

    2016-05-01

    The formulary inclusion of proton pump inhibitors (PPIs) in the government hospital health services in Qatar is not comparative or restricted. Requests to include a PPI in the formulary are typically accepted if evidence of efficacy and tolerability is presented. There are no literature reports of a PPI scoring model that is based on comparatively weighted multiple indications and no reports of PPI selection in Qatar or the Middle East. This study aims to compare first-line use of the PPIs that exist in Qatar. The economic effect of the study recommendations was also quantified. A comparative, evidence-based multicriteria decision analysis (MCDA) model was constructed to follow the multiple indications and pharmacotherapeutic criteria of PPIs. Literature and an expert panel informed the selection criteria of PPIs. Input from the relevant local clinician population steered the relative weighting of selection criteria. Comparatively scored PPIs, exceeding a defined score threshold, were recommended for selection. Weighted model scores were successfully developed, with 95% CI and 5% margin of error. The model comprised 7 main criteria and 38 subcriteria. Main criteria are indication, dosage frequency, treatment duration, best published evidence, available formulations, drug interactions, and pharmacokinetic and pharmacodynamic properties. Most weight was achieved for the indications selection criteria. Esomeprazole and rabeprazole were suggested as formulary options, followed by lansoprazole for nonformulary use. The estimated effect of the study recommendations was up to a 15.3% reduction in the annual PPI expenditure. Robustness of study conclusions against variabilities in study inputs was confirmed via sensitivity analyses. The implementation of a locally developed PPI-specific comparative MCDA scoring model, which is multiweighted indication and criteria based, into the Qatari formulary selection practices is a successful evidence-based cost-cutting exercise

  1. Delayed-type hypersensitivity reactions induced by proton pump inhibitors: A clinical and in vitro T-cell reactivity study.

    Science.gov (United States)

    Lin, C-Y; Wang, C-W; Hui, C-Y R; Chang, Y-C; Yang, C-H; Cheng, C-Y; Chen, W-W; Ke, W-M; Chung, W-H

    2017-06-28

    Proton pump inhibitors (PPIs) have been known to induce type I hypersensitivity reactions. However, severe delayed-type hypersensitivity reactions (DHR) induced by PPI, such as Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), or drug rash with eosinophilia and systemic symptoms (DRESS), are rarely reported. We conducted a study of a large series of PPI-related DHR, followed up their tolerability to alternative anti-ulcer agents, and investigated the T-cell reactivity to PPI in PPI-related DHR patients. We retrospectively analyzed patients with PPI-related DHR from multiple medical centers in Taiwan during the study period January 2003 to April 2016. We analyzed the causative PPI, clinical manifestations, organ involvement, treatment, and complications. We also followed up the potential risk of cross-hypersensitivity or tolerability to other PPI after their hypersensitivity episodes. Drug lymphocyte activation test (LAT) was conducted by measuring granulysin and interferon-γ to confirm the causalities. There were 69 cases of PPI-related DHR, including SJS/TEN (n=27) and DRESS (n=10). The LAT by measuring granulysin showed a sensitivity of 59.3% and specificity of 96.4%. Esomeprazole was the most commonly involved in PPI-related DHR (51%). Thirteen patients allergic to one kind of PPI could tolerate other structurally different PPI without cross-hypersensitivity reactions, whereas three patients developed cross-hypersensitivity reactions to alternative structurally similar PPI. The cross-reactivity to structurally similar PPI was also observed in LAT assay. PPIs have the potential to induce life-threatening DHR. In patients when PPI is necessary for treatment, switching to structurally different alternatives should be considered. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  2. In vitro dissolution of proton-pump inhibitor products intended for paediatric and geriatric use in physiological bicarbonate buffer.

    Science.gov (United States)

    Liu, Fang; Shokrollahi, Honaz

    2015-05-15

    Proton-pump inhibitor (PPI) products based on enteric coated multiparticulates are design to meet the needs of patients who cannot swallow tablets such as children and older adults. Enteric coated PPI preparations exhibit delays in in vivo absorption and onset of antisecretory effects, which is not reflected by the rapid in vitro dissolution in compendial pH 6.8 phosphate buffer commonly used for assessment of these products. A more representative and physiological medium, pH 6.8 mHanks bicarbonate buffer, was used in this study to evaluate the in vitro dissolution of enteric coated multiparticulate-based PPI products. Commercially available omeprazole, lansoprazole and esomeprazole products were subject to dissolution tests using USP-II apparatus in pH 4.5 phosphate buffer saline for 45 min (acid stage) followed by pH 6.8 phosphate buffer or pH 6.8 mHanks bicarbonate buffer. In pH 6.8 phosphate buffer, all nine tested products displayed rapid and comparable dissolution profiles meeting the pharmacopeia requirements for delayed release preparations. In pH 6.8 mHanks buffer, drug release was delayed and failed the pharmacopeia requirements from most enteric coated preparations. Despite that the same enteric polymer, methacrylic acid-ethyl acrylate copolymer (1:1), was applied to all commercial multiparticulate-based products, marked differences were observed between dissolution profiles of these preparations. The use of pH 6.8 physiological bicarbonate (mHanks) buffer can serve as a useful tool to provide realistic and discriminative in vitro release assessment of enteric coated PPI preparations and to assist rational formulation development of these products. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Asthma symptoms improvement in moderate persistent asthma patients with gastroesophageal reflux disease (GERD: the role of proton-pump inhibitor

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    Agus D. Susanto

    2008-09-01

    Full Text Available This study aimed to evaluate effect of proton pump inhibitor (esomeprazole on asthma symptoms, use of inhaled bronchodilator and peak expiratory flow rate (PEFR in moderate persistent asthma with gastroesofageal refluks disease (GERD. This randomized single blind, controlled clinical trial study was conducted at Persahabatan Hospital, Jakarta from July 2004 until October 2005. Samples were moderate persistent asthma patients with GERD. GERD is diagnosed GERD symptoms and proof of oesophagitis from endoscopy and or histapatologic examination from oesophagus biopsy. Phase 1:2 week run-in period patient received inhaled budesonide 2x200 ug/day. Phase 2: patient randomised to receive inhaled budesonide 2 x 400 ug/day with esomeprazole 40 mg/day or without esomeprazole (control group for 8 weeks. Phase 3: 4 week wash out period, patient receive inhaled budesonide 2 x 200 ug/day. Diary cards were assessed at run-in periode, after treatment 4 weeks, 8 weeks and wash out. There were 32 patients (23 female and 9 male completed the study. Mean total asthma symptoms score daily were significantly decreased on esomeprazole vs without esomeprazole after 8 weeks (-2.29 vs -0.90; p < 0.05. Mean use of inhaled bronchodilator was significantly decreased on esomeprazole vs without esomeprazole after 8 weeks (-1.09 vs -0.42; p < 0.05. Morning and evening PEFR improved higher on esomeprazole than without esomeprazol but were not significantly difference. In conclusion, administration esomeprazole 40 mg daily improved asthma symptoms and lower the use of inhaled bronchodilator in moderate persistent asthma patients with GERD. (Med J Indones 2008; 17: 169-74Keywords: Asthma symptoms, inhaled bronchodilator, moderate persistent asthma, GERD, esomeprazole

  4. Changes in Practice Patterns of Clopidogrel in Combination with Proton Pump Inhibitors after an FDA Safety Communication.

    Directory of Open Access Journals (Sweden)

    Annie Guérin

    Full Text Available In 2009, the FDA issued a warning that omeprazole--a proton pump inhibitor (PPI--reduces the antithrombotic effect of clopidogrel by almost half when taken concomitantly. This study aims to analyze the impact of the FDA Safety Communications on prescribing clopidogrel together with PPIs.This retrospective study identified clopidogrel users from the Truven Health Analytics MarketScan Databases (01/2006-12/2012. Rates of clopidogrel-PPI combination therapy were estimated in 6-month intervals for patients with ≥1 clopidogrel prescription fill, then were analyzed pre- and post-safety communication (11/17/2009. Analyses were also conducted by grouping PPIs into CYP2C19 inhibitors (omeprazole and esomeprazole and CYP2C19 non-inhibitors (pantoprazole, lansoprazole, dexlansoprazole, and rabeprazole.Overall, 483,074 patients met the selection criteria; of these, 157,248 used a clopidogrel-PPI combination. On average, 30.5% of patients in the pre- and 19.9% in the post-communication period used a clopidogrel-PPI combination therapy. Among clopidogrel users, the probability of using clopidogrel-PPI combinations fell by over 40% in the post-communication period (OR = 0.57; p<0.001; the proportion of patients using esomeprazole fell from 12.9% to 5.3%, and the proportion using omeprazole fell from 10.1% to 6.3%. Among combination therapy users, the probability of patients using a combination with a CYP2C19 inhibitor decreased by 53% (OR = 0.47; p<0.001; however, 31.5% of patients were still prescribed a clopidogrel-PPI combination therapy. Trends were similar for all and newly treated patients, regardless of clopidogrel indication and physician specialty.The FDA Safety Communication resulted in a reduction in the number of patients undergoing combination therapy; however approximately one-third of patients still used combination therapy post-communication.

  5. Effectiveness of ranitidine bismuth citrate and proton pump inhibitor based triple therapies of Helicobacter pylori in Turkey

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    Mustafa Iscan

    2011-09-01

    Full Text Available Background : Helicobacter pylori infection is the main cause of gastritis, gastroduodenal ulcer disease, MALT lymphoma, and adenocarcinoma of the stomach. The reported prevalence of H. pylori in the adult population in Turkey is 67.6%–81.3%. A national meta-analysis showed that the average H. pylori eradication rate with proton pump inhibitor-based triple regimens in Turkey had decreased from 84% in 1997 to 55.3% in 2004, suggesting a need to evaluate alternative regimens. Materials and methods : The study was a prospective, single-center trial with a parallel group design. After the selection procedure, consecutive out-patients were assigned to one of six study groups using random sampling numbers. All patients received amoxicillin 1,000 mg b.i.d. and clarithromycin 500 mg b.i.d. along with ranitidine bismuth citrate 400 mg b.i.d., or omeprazole 20 mg b.i.d., or lansoprazole 30 mg b.i.d., or rabeprazole 20 mg b.i.d., or pantoprazole 40 mg b.i.d., or esomeprazole 40 mg b.i.d. for 14 days. Results : When we look at the eradication rates of the treatment groups, only two groups (ranitidine bismuth citrate and rabeprazole groups had eradication rates greater than 80%, both at intention to treat and per protocol analyses. The other four groups (omeprazole, lansoprazole, pantoprazole, and esomeprazole groups showed statistically significant lower eradication rates both at intention to treat (between 57.6 and 66.7% and per protocol (between 60.3 and 72.1% analyses when compared with ranitidine bismuth citrate and rabeprazole groups (p<.05. Conclusion : Ranitidine bismuth citrate and/or rabeprazole based triple therapies must be preferred for the first-line treatment of H. pylori infection.

  6. Rational use of nonsteroidal anti-inflammatory drugs and proton pump inhibitors in combination for rheumatic diseases

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    Wolfgang W Bolten

    2010-09-01

    Full Text Available Wolfgang W BoltenDivision of Rheumatology, Klaus-Miehlke Klinik, Wiesbaden, GermanyAbstract: Nonsteroidal anti-inflammatory drugs (NSAIDs are successfully used to alleviate pain and inflammation in rheumatic diseases. In an appreciable percentage of cases, the use of systemic NSAIDs is associated with adverse lesions of the gastrointestinal (GI mucosa up to life-threatening perforations, ulcers, and bleeding. Reliable warning signals mostly do not arise. Therefore, it is important to take preventive measures to reduce the GI risk. One established method is to assign cyclooxygenase 2 (COX-2-specific inhibitors (coxibs instead of traditional NSAIDs (tNSAIDs. Coxibs spare in part the endogenous gastroprotective mechanisms. Another reliable choice to improve the GI safety is the comedication of proton pump inhibitors (PPIs to suppress gastric acid. A fixed NSAID/PPI combination ensures expected protective effects by improving patients’ PPI adherence and physicians’ PPI prescription persistence. A fixed combination of enteric-coated naproxen and immediate-release esomeprazole has just been approved by the US Food and Drug Administration. PPI combinations with aspirin, other tNSAIDs, and coxibs are desirable. Patients in all risk groups, even patients at low risk of GI adverse events, benefit from concomitant protective measures. Moreover, the literature suggests that NSAID/PPI combinations are cost effective, including for patients in low-GI-risk groups. Pricing of fixed NSAID/PPI combinations will play a pivotal role for their broad acceptance in the future.Keywords: PPI, NSAID, fixed combination, gastrointestinal, adverse events, prevention

  7. Radiation lethality potentiation in total body irradiated mice by a commonly prescribed proton pump inhibitor, Pantoprazole sodium.

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    Biju, Prabath G; Gubrij, Igor; Garg, Sarita; Gupta, Prem K; Hauer-Jensen, Martin; Burnett, Alexander F

    2014-07-01

    Pantoprazole sodium (Protonix) is a proton pump inhibitor (PPI) widely used to treat peptic ulcer and gastroesophageal reflux due to its ability to inhibit gastric acid secretion. Therefore, a large group of the population exposed to total body irradiation (TBI) in the event of a nuclear disaster would be on this or similar medications. We investigated the effect of pantoprazole on TBI-induced lethality in mice. Male CD2F1 mice were exposed to various doses of uniform TBI using a (137)Cs irradiator. Pantoprazole was administered by twice daily subcutaneous injection in saline from 4 days before to 5 days after irradiation. Effects on gastric pH, and gastrointestinal (GI) and hematopoietic toxicity were evaluated. Pantoprazole administration significantly exacerbated 30 day lethality and gastrointestinal toxicity. Median survival after 9.0 Gy TBI was reduced from 22 days to 12 days (p = 0.006). Pantoprazole adversely effected intestinal crypt survival and mucosal surface area. In contrast, equivalent doses of a histamine type-2(H2) receptor blocker (cimetidine) did not alter TBI-induced lethality. The adverse effect of pantoprazole on TBI-induced lethality is highly important because of the widespread use of PPI in the general population, as well as use of these drugs for acid suppression in individuals exposed to radiation. Further studies of the mechanisms underlying the adverse effect of PPI after exposure to TBI are clearly warranted. Until results from such studies are available, other acid-suppressing strategies should be preferred in the context of radiation exposure.

  8. A dipeptidyl peptidase-4 inhibitor ameliorates hypertensive cardiac remodeling via angiotensin-II/sodium-proton pump exchanger-1 axis.

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    Kawase, Haruya; Bando, Yasuko K; Nishimura, Kazuyuki; Aoyama, Morihiko; Monji, Akio; Murohara, Toyoaki

    2016-09-01

    To address the impact of antidiabetic drugs on cardiovascular safety is a matter of clinical concern. Preclinical studies revealed that various protective effects of dipeptidyl peptidase-4 inhibitor (DPP4i) on cardiovascular disease; however, its impact of on hypertension remains controversial. Teneligliptin (TEN; 10mg/kg/day/p.o.) ameliorates hypertension and cardiac remodeling by normalizing a rise of angiotensin-II (AngII) that specifically observed in spontaneously hypertensive rats (SHR). TEN had no effects on vasculature and concentrations of the DPP4-related vasoactive peptides (bradykinin, neuropeptide Y, and atrial natriuretic peptide). The primary action of TEN on BP lowering was due to restoring the AngII-induced manifestation of congestive heart failure observed in SHR. Sodium-proton pump exchanger type 1 (NHE-1) is a regulator of intracellular acidity (pHi) and implicated pathophysiological role in cardiac remodeling occurred in diseased myocardium. Cardiac NHE-1 expression level was increased in SHR and this was restored in TEN-treated SHR. AngII directly augmented cardiac NHE-1 expression and its activity that contributed to hypertrophic response. TEN attenuated the AngII-induced cardiac hypertrophy with decline in pHi via suppression of NHE-1. Loss of NHE-1 activity by specific inhibitor or RNA silencing promoted intracellular acidification and consistently attenuated the AngII-mediated cardiac hypertrophy. The present study revealed the protective actions of TEN on hypertension and comorbid cardiac remodeling via AngII/NHE-1 axis and the novel pathophysiological roles of intracellular acidification via NHE-1 in cardiac hypertrophy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Changes in Practice Patterns of Clopidogrel in Combination with Proton Pump Inhibitors after an FDA Safety Communication

    Science.gov (United States)

    Guérin, Annie; Mody, Reema; Carter, Valerie; Ayas, Charles; Patel, Haridarshan; Lasch, Karen; Wu, Eric

    2016-01-01

    Objectives In 2009, the FDA issued a warning that omeprazole–a proton pump inhibitor (PPI)–reduces the antithrombotic effect of clopidogrel by almost half when taken concomitantly. This study aims to analyze the impact of the FDA Safety Communications on prescribing clopidogrel together with PPIs. Methods This retrospective study identified clopidogrel users from the Truven Health Analytics MarketScan Databases (01/2006–12/2012). Rates of clopidogrel-PPI combination therapy were estimated in 6-month intervals for patients with ≥1 clopidogrel prescription fill, then were analyzed pre- and post-safety communication (11/17/2009). Analyses were also conducted by grouping PPIs into CYP2C19 inhibitors (omeprazole and esomeprazole) and CYP2C19 non-inhibitors (pantoprazole, lansoprazole, dexlansoprazole, and rabeprazole). Results Overall, 483,074 patients met the selection criteria; of these, 157,248 used a clopidogrel-PPI combination. On average, 30.5% of patients in the pre- and 19.9% in the post-communication period used a clopidogrel-PPI combination therapy. Among clopidogrel users, the probability of using clopidogrel-PPI combinations fell by over 40% in the post-communication period (OR = 0.57; pclopidogrel-PPI combination therapy. Trends were similar for all and newly treated patients, regardless of clopidogrel indication and physician specialty. Conclusions The FDA Safety Communication resulted in a reduction in the number of patients undergoing combination therapy; however approximately one-third of patients still used combination therapy post-communication. PMID:26727382

  10. Cardiovascular outcomes associated with concomitant use of clopidogrel and proton pump inhibitors in patients with acute coronary syndrome in Taiwan

    Science.gov (United States)

    Lin, Chen-Fang; Shen, Li-Jiuan; Wu, Fe-Lin Lin; Bai, Chyi-Huey; Gau, Churn-Shiouh

    2012-01-01

    AIMS Our study aimed to examine the impact of concomitant use of proton pump inhibitors (PPIs) with clopidogrel on the cardiovascular outcomes of patients with acute coronary syndrome (ACS). Furthermore, we sought to quantify the effects of five individual PPIs when used concomitantly with clopidogrel. METHODS We conducted a retrospective cohort study of patients who were newly hospitalized for ACS between 1 January 2006 and 31 December 2007 retrieved from the Taiwan National Health Insurance Research Database (NHIRD) and who were prescribed clopidogrel (n= 37 099) during the follow-up period. A propensity score technique was used to establish a matched cohort in 1:1 ratio (n= 5173 for each group). The primary clinical outcome was rehospitalization for ACS, while secondary outcomes were rehospitalization for percutaneous transluminal coronary angioplasty (PTCA) with stent, PTCA without stent and revascularization (PTCA or coronary artery bypass graft surgery) after the discharge date for the index ACS event. RESULTS The adjusted hazard ratio of rehospitalization for ACS was 1.052 (95% confidence interval, 0.971–1.139; P= 0.214) in the propensity score matched cohort. Among all PPIs, only omeprazole was found to be statistically significantly associated with an increased risk of rehospitalization for ACS (adjusted hazard ratio, 1.226; 95% confidence interval, 1.066–1.410; P= 0.004). Concomitant use of esomeprazole, pantoprazole, rabeprazole and lansoprazole did not increase the risk. CONCLUSIONS Our study indicated no statistically significant increase in the risk of rehospitalization for ACS due to concurrent use of clopidogrel and PPIs overall. Among individual PPIs, only omeprazole was found to be statistically significantly associated with increased risk of rehospitalization for ACS. PMID:22364155

  11. Influence of low-dose proton pump inhibitors administered concomitantly or separately on the anti-platelet function of clopidogrel.

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    Furuta, Takahisa; Sugimoto, Mitsushige; Kodaira, Chise; Nishino, Masafumi; Yamade, Mihoko; Uotani, Takahiro; Sahara, Shu; Ichikawa, Hitomi; Kagami, Takuma; Iwaizumi, Moriya; Hamaya, Yasushi; Osawa, Satoshi; Sugimoto, Ken; Umemura, Kazuo

    2017-04-01

    Proton pump inhibitors (PPIs) at low doses can effectively prevent gastrointestinal bleeding due to aspirin and are widely used in Japan for gastroprotection in patients taking anti-platelet agents. We examined the influence of different PPIs at low doses administered concomitantly or separately on anti-platelet functions of clopidogrel. In 41 healthy Japanese volunteers with different CYP2C19 genotypes who took clopidogrel 75 mg in the morning alone, or with omeprazole 10 mg, esomeprazole 10 mg, lansoprazole 15 mg, or rabeprazole 10 mg, either concomitantly in the morning or separately in the evening, we measured the inhibition of platelet aggregation (IPA, %) using VerifyNow P2Y12 assay at 4 h after the last clopidogrel dose on Day 7 of each regimen. IPA by clopidogrel with rabeprazole administered at lunchtime, approximately 4 h after clopidogrel, was also measured. Mean IPAs in those concomitantly receiving omeprazole, esomeprazole, lansoprazole or rabeprazole (47.2 ± 21.1%, 43.2 ± 20.2%, 46.4 ± 18.8%, and 47.3 ± 19.2%, respectively) were significantly decreased compared with those receiving clopidogrel alone (56.0%) (all ps clopidogrel with rabeprazole administered at lunchtime was 51.6%, which was markedly similar to that of clopidogrel alone (p = 0.114). All tested PPIs reduce the efficacy of clopidogrel when administered concomitantly. Our preliminary data suggest that administration of rabeprazole 4 h following clopidogrel may minimize potential drug-drug interactions.

  12. Liposome Model Systems to Study the Endosomal Escape of Cell-Penetrating Peptides: Transport across Phospholipid Membranes Induced by a Proton Gradient

    Directory of Open Access Journals (Sweden)

    Fatemeh Madani

    2011-01-01

    Full Text Available Detergent-mediated reconstitution of bacteriorhodopsin (BR into large unilamellar vesicles (LUVs was investigated, and the effects were carefully characterized for every step of the procedure. LUVs were prepared by the extrusion method, and their size and stability were examined by dynamic light scattering. BR was incorporated into the LUVs using the detergent-mediated reconstitution method and octyl glucoside (OG as detergent. The result of measuring pH outside the LUVs suggested that in the presence of light, BR pumps protons from the outside to the inside of the LUVs, creating acidic pH inside the vesicles. LUVs with 20% negatively charged headgroups were used to model endosomes with BR incorporated into the membrane. The fluorescein-labeled cell-penetrating peptide penetratin was entrapped inside these BR-containing LUVs. The light-induced proton pumping activity of BR has allowed us to observe the translocation of fluorescein-labeled penetratin across the vesicle membrane.

  13. A Comparison of Alkaline Water and Mediterranean Diet vs Proton Pump Inhibition for Treatment of Laryngopharyngeal Reflux.

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    Zalvan, Craig H; Hu, Shirley; Greenberg, Barbara; Geliebter, Jan

    2017-10-01

    Laryngopharyngeal reflux (LPR) is a common disorder with protean manifestations in the head and neck. In this retrospective study, we report the efficacy of a wholly dietary approach using alkaline water, a plant-based, Mediterranean-style diet, and standard reflux precautions compared with that of the traditional treatment approach of proton pump inhibition (PPI) and standard reflux precautions. To determine whether treatment with a diet-based approach with standard reflux precautions alone can improve symptoms of LPR compared with treatment with PPI and standard reflux precautions. This was a retrospective medical chart review of 2 treatment cohorts. From 2010 to 2012, 85 patients with LPR that were treated with PPI and standard reflux precautions (PS) were identified. From 2013 to 2015, 99 patients treated with alkaline water (pH >8.0), 90% plant-based, Mediterranean-style diet, and standard reflux precautions (AMS) were identified. The outcome was based on change in Reflux Symptom Index (RSI). Recorded change in the RSI after 6 weeks of treatment. Of the 184 patients identified in the PS and AMS cohorts, the median age of participants in each cohort was 60 years (95% CI, 18-82) and 57 years (95% CI, 18-93), respectively (47 [56.3%] and 61 [61.7%] were women, respectively). The percentage of patients achieving a clinically meaningful (≥6 points) reduction in RSI was 54.1% in PS-treated patients and 62.6% in AMS-treated patients (difference between the groups, 8.05; 95% CI, -5.74 to 22.76). The mean reduction in RSI was 27.2% for the PS group and 39.8% in the AMS group (difference, 12.10; 95% CI, 1.53 to 22.68). Our data suggest that the effect of PPI on the RSI based on proportion reaching a 6-point reduction in RSI is not significantly better than that of alkaline water, a plant-based, Mediterranean-style diet, and standard reflux precautions, although the difference in the 2 treatments could be clinically meaningful in favor of the dietary approach. The

  14. Proton-Pump Inhibitors Reduce Gastrointestinal Events Regardless of Aspirin Dose in Patients Requiring Dual Antiplatelet Therapy.

    Science.gov (United States)

    Vaduganathan, Muthiah; Bhatt, Deepak L; Cryer, Byron L; Liu, Yuyin; Hsieh, Wen-Hua; Doros, Gheorghe; Cohen, Marc; Lanas, Angel; Schnitzer, Thomas J; Shook, Thomas L; Lapuerta, Pablo; Goldsmith, Mark A; Laine, Loren; Cannon, Christopher P

    2016-04-12

    The COGENT (Clopidogrel and the Optimization of Gastrointestinal Events Trial) showed that proton-pump inhibitors (PPIs) safely reduced rates of gastrointestinal (GI) events in patients requiring dual antiplatelet therapy (DAPT). However, utilization of appropriate prophylactic PPI therapy remains suboptimal, especially with low-dose aspirin. The authors investigated the safety and efficacy of PPI therapy in patients receiving DAPT in low- and high-dose aspirin subsets. Randomized patients with available aspirin dosing information in COGENT (N = 3,752) were divided into "low-dose" (≤ 100 mg) and "high-dose" (>100 mg) aspirin groups. The primary GI and cardiovascular endpoints were composite upper GI events and major adverse cardiac events, respectively. All events were adjudicated by independent, blinded gastroenterologists and cardiologists. Median duration of follow-up was 110 days. Low-dose aspirin users (n = 2,480; 66.1%) were more likely to be older, female, and have higher rates of peripheral artery disease, prior stroke, and hypertension, whereas high-dose aspirin users (n = 1,272; 33.9%) had higher rates of hyperlipidemia, smoking, a history of percutaneous coronary intervention, and were more than twice as likely to be enrolled from sites within the United States (80.4% vs. 39.8%). High-dose aspirin was associated with similar 180-day Kaplan-Meier estimates of adjudicated composite GI events (1.7% vs. 2.1%; adjusted hazard ratio: 0.88; 95% confidence interval: 0.46 to 1.66) and major adverse cardiac events (4.8% vs. 5.5%; adjusted hazard ratio: 0.73; 95% confidence interval: 0.48 to 1.11) compared with low-dose aspirin. Randomization to PPI therapy reduced 180-day Kaplan-Meier estimates of the primary GI endpoint in low-dose (1.2% vs. 3.1%) and high-dose aspirin subsets (0.9% vs. 2.6%; p for interaction = 0.80), and did not adversely affect the primary cardiovascular endpoint in either group. Gastroprotection with PPI therapy should be utilized in

  15. Risk factors associated with gastroesophageal reflux disease relapse in primary care patients successfully treated with a proton pump inhibitor.

    Science.gov (United States)

    López-Colombo, A; Pacio-Quiterio, M S; Jesús-Mejenes, L Y; Rodríguez-Aguilar, J E G; López-Guevara, M; Montiel-Jarquín, A J; López-Alvarenga, J C; Morales-Hernández, E R; Ortiz-Juárez, V R; Ávila-Jiménez, L

    There are no studies on the factors associated with gastroesophageal reflux disease (GERD) relapse in primary care patients. To identify the risk factors associated with GERD relapse in primary care patients that responded adequately to short-term treatment with a proton pump inhibitor. A cohort study was conducted that included GERD incident cases. The patients received treatment with omeprazole for 4 weeks. The ReQuest questionnaire and a risk factor questionnaire were applied. The therapeutic success rate and relapse rate were determined at 4 and 12 weeks after treatment suspension. A logistic regression analysis of the possible risk factors for GERD relapse was carried out. Of the 83 patient total, 74 (89.16%) responded to treatment. Symptoms recurred in 36 patients (48.64%) at 4 weeks and in 13 patients (17.57%) at 12 weeks, with an overall relapse rate of 66.21%. The OR multivariate analysis (95% CI) showed the increases in the possibility of GERD relapse for the following factors at 12 weeks after treatment suspension: basic educational level or lower, 24.95 (1.92-323.79); overweight, 1.76 (0.22-13.64); obesity, 0.25 (0.01-3.46); smoking, 0.51 (0.06-3.88); and the consumption of 4-12 cups of coffee per month, 1.00 (0.12-7.84); citrus fruits, 14.76 (1.90-114.57); NSAIDs, 27.77 (1.12-686.11); chocolate, 0.86 (0.18-4.06); ASA 1.63 (0.12-21.63); carbonated beverages, 4.24 (0.32-55.05); spicy food 7-16 times/month, 1.39 (0.17-11.17); and spicy food ≥ 20 times/month, 4.06 (0.47-34.59). The relapse rate after short-term treatment with omeprazole was high. The consumption of citrus fruits and NSAIDs increased the possibility of GERD relapse. Copyright © 2016 Asociación Mexicana de Gastroenterología. Publicado por Masson Doyma México S.A. All rights reserved.

  16. Cost Effectiveness of Gastroprotection with Proton Pump Inhibitors in Older Low-Dose Acetylsalicylic Acid Users in the Netherlands.

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    Chau, Sek Hung; Sluiter, Reinier L; Kievit, Wietske; Wensing, Michel; Teichert, Martina; Hugtenburg, Jacqueline G

    2017-05-01

    The present study aimed to assess the cost effectiveness of concomitant proton pump inhibitor (PPI) treatment in low-dose acetylsalicylic acid (LDASA) users at risk of upper gastrointestinal (UGI) adverse effects as compared with no PPI co-medication with attention to the age-dependent influence of PPI-induced adverse effects. We used a Markov model to compare the strategy of PPI co-medication with no PPI co-medication in older LDASA users at risk of UGI adverse effects. As PPIs reduce the risk of UGI bleeding and dyspepsia, these risk factors were modelled together with PPI adverse effects for LDASA users 60-69, 70-79 (base case) and 80 years and older. Incremental cost-utility ratios (ICURs) were calculated as cost per quality-adjusted life-year (QALY) gained per age category. Furthermore, a budget impact analysis assessed the expected changes in expenditure of the Dutch healthcare system following the adoption of PPI co-treatment in all LDASA users potentially at risk of UGI adverse effects. PPI co-treatment of 70- to 79-year-old LDASA users, as compared with no PPI, resulted in incremental costs of €100.51 at incremental effects of 0.007 QALYs with an ICUR of €14,671/QALY. ICURs for 60- to 69-year-old LDASA users were €13,264/QALY and €64,121/QALY for patients 80 years and older. Initiation of PPI co-treatment for all Dutch LDASA users of 60 years and older at risk of UGI adverse effects but not prescribed a PPI (19%) would have cost €1,280,478 in the first year (year 2013 values). PPI co-medication in LDASA users at risk of UGI adverse effects is generally cost effective. However, this strategy becomes less cost effective with higher age, particularly in patients aged 80 years and older, mainly due to the increased risks of PPI-induced adverse effects.

  17. Cost-Effectiveness of Histamine2 Receptor Antagonists Versus Proton Pump Inhibitors for Stress Ulcer Prophylaxis in Critically Ill Patients.

    Science.gov (United States)

    Hammond, Drayton A; Kathe, Niranjan; Shah, Anuj; Martin, Bradley C

    2017-01-01

    To determine the cost-effectiveness of stress ulcer prophylaxis with histamine2 receptor antagonists (H2RAs) versus proton pump inhibitors (PPIs) in critically ill and mechanically ventilated adults. A decision analytic model estimating the costs and effectiveness of stress ulcer prophylaxis (with H2RAs and PPIs) from a health care institutional perspective. Adult mixed intensive care unit (ICU) population who received an H2RA or PPI for up to 9 days. Effectiveness measures were mortality during the ICU stay and complication rate. Costs (2015 U.S. dollars) were combined to include medication regimens and untoward events associated with stress ulcer prophylaxis (pneumonia, Clostridium difficile infection, and stress-related mucosal bleeding). Costs and probabilities for complications and mortality from complications came from randomized controlled trials and observational studies. A base case scenario was developed with pooled data from an observational study and meta-analysis of randomized controlled trials. Scenarios based on observational and meta-analysis data alone were evaluated. Outcomes were expected and incremental costs, mortalities, and complication rates. Univariate sensitivity analyses were conducted to determine the influence of inputs on cost, mortality, and complication rates. Monte Carlo simulations evaluated second-order uncertainty. In the base case scenario, the costs, complication rates, and mortality rates were $9039, 17.6%, and 2.50%, respectively, for H2RAs and $11,249, 22.0%, and 3.34%, respectively, for PPIs, indicating that H2RAs dominated PPIs. The observational study-based model provided similar results; however, in the meta-analysis-based model, H2RAs had a cost of $8364 and mortality rate of 3.2% compared with $7676 and 2.0%, respectively, for PPIs. At a willingness-to-pay threshold of $100,000/death averted, H2RA therapy was superior or preferred 70.3% in the base case and 97.0% in the observational study-based scenario. PPI therapy

  18. Algorithmic approach to patients presenting with heartburn and epigastric pain refractory to empiric proton pump inhibitor therapy.

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    Roorda, Andrew K; Marcus, Samuel N; Triadafilopoulos, George

    2011-10-01

    Reflux-like dyspepsia (RLD), where predominant epigastric pain is associated with heartburn and/or regurgitation, is a common clinical syndrome in both primary and specialty care. Because symptom frequency and severity vary, overlap among gastroesophageal reflux disease (GERD), non-erosive reflux disease (NERD), and RLD, is quite common. The chronic and recurrent nature of RLD and its variable response to proton pump inhibitor (PPI) therapy remain problematic. To examine the prevalence of GERD, NERD, and RLD in a community setting using an algorithmic approach and to assess the potential, reproducibility, and validity of a multi-factorial scoring system in discriminating patients with RLD from those with GERD or NERD. Using a novel algorithmic approach, we evaluated an outpatient, community-based cohort referred to a gastroenterologist because of epigastric pain and heartburn that were only partially relieved by PPI. After an initial symptom evaluation (for epigastric pain, heartburn, regurgitation, dysphagia), an endoscopy and distal esophageal biopsies were performed, followed by esophageal motility and 24-h ambulatory pH monitoring to assess esophageal function and pathological acid exposure. A scoring system based on presence of symptoms and severity of findings was devised. Data was collected in two stages: subjects in the first stage were designated as the derivation cohort; subjects in the second stage were labeled the validation cohort. The total cohort comprised 159 patients (59 males, 100 females; mean age 52). On endoscopy, 30 patients (19%) had complicated esophagitis (CE) and 11 (7%) had Barrett's esophagus (BE) and were classified collectively as patients with GERD. One-hundred and eighteen (74%) patients had normal esophagus. Of these, 94 (59%) had one or more of the following: hiatal hernia, positive biopsy, abnormal pH, and/or abnormal motility studies and were classified as patients with NERD. The remaining 24 patients (15%) had normal functional

  19. Impact of proton pump inhibitor therapy on the efficacy of clopidogrel in the CAPRIE and CREDO trials.

    Science.gov (United States)

    Dunn, Steven P; Steinhubl, Steven R; Bauer, Deborah; Charnigo, Richard J; Berger, Peter B; Topol, Eric J

    2013-01-15

    Proton pump inhibitors (PPIs) may interfere with the metabolic activation of clopidogrel via inhibition of cytochrome P450 2C19, but the clinical implications remain unclear. The impact of PPI use on the 1-year primary end point (ischemic stroke, myocardial infarction [MI], or vascular death) in the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial and the 28-day (all-cause death, MI, or urgent target vessel revascularization) and 1-year (all-cause death, MI, or stroke) primary end points in the Clopidogrel for Reduction of Events During Observation (CREDO) trial were examined. Clopidogrel appeared to elevate risk for the primary end point in CAPRIE among PPI users (estimated hazard ratio [EHR] 2.66, 95% CI 0.94 to 7.50) while lowering it for non-PPI users (EHR 0.90, 95% CI 0.83 to 0.99, interaction P=0.047). Moreover, PPI use was associated with worse outcomes in patients receiving clopidogrel (EHR 2.39, 95% CI 1.74 to 3.28) but not aspirin (EHR 1.04, 95% CI 0.70 to 1.57, interaction P=0.001). Clopidogrel did not significantly alter risk for the 1-year primary end point in CREDO among PPI users (EHR 0.82, 95% CI 0.48 to 1.40) while lowering it for non-PPI users (EHR 0.71, 95% CI 0.52 to 0.98, interaction P=0.682). Also, PPI use was associated with worse outcomes in both patients receiving clopidogrel (EHR 1.67, 95% CI 1.06 to 2.64) and those receiving placebo (EHR 1.56, 95% CI 1.06 to 2.30, interaction P=0.811). In CREDO, the efficacy of clopidogrel was not significantly affected by PPI use. However, in CAPRIE, clopidogrel was beneficial to non-PPI users while apparently harmful to PPI users. Whether this negative interaction is clinically important for patients receiving clopidogrel without aspirin needs further study.

  20. Impact of Proton Pump Inhibitor Therapy on the Efficacy of Clopidogrel in the CAPRIE and CREDO Trials

    Science.gov (United States)

    Dunn, Steven P.; Steinhubl, Steven R.; Bauer, Deborah; Charnigo, Richard J.; Berger, Peter B.; Topol, Eric J.

    2013-01-01

    Background Proton pump inhibitors (PPIs) may interfere with the metabolic activation of clopidogrel via inhibition of cytochrome P450 2C19, but the clinical implications remain unclear. Methods and Results The impact of PPI use on the 1‐year primary end point (ischemic stroke, myocardial infarction [MI], or vascular death) in the Clopidogrel versus Aspirin in Patients at Risk of Ischemic Events (CAPRIE) trial and the 28‐day (all‐cause death, MI, or urgent target vessel revascularization) and 1‐year (all‐cause death, MI, or stroke) primary end points in the Clopidogrel for Reduction of Events During Observation (CREDO) trial were examined. Clopidogrel appeared to elevate risk for the primary end point in CAPRIE among PPI users (estimated hazard ratio [EHR] 2.66, 95% CI 0.94 to 7.50) while lowering it for non‐PPI users (EHR 0.90, 95% CI 0.83 to 0.99, interaction P=0.047). Moreover, PPI use was associated with worse outcomes in patients receiving clopidogrel (EHR 2.39, 95% CI 1.74 to 3.28) but not aspirin (EHR 1.04, 95% CI 0.70 to 1.57, interaction P=0.001). Clopidogrel did not significantly alter risk for the 1‐year primary end point in CREDO among PPI users (EHR 0.82, 95% CI 0.48 to 1.40) while lowering it for non‐PPI users (EHR 0.71, 95% CI 0.52 to 0.98, interaction P=0.682). Also, PPI use was associated with worse outcomes in both patients receiving clopidogrel (EHR 1.67, 95% CI 1.06 to 2.64) and those receiving placebo (EHR 1.56, 95% CI 1.06 to 2.30, interaction P=0.811). Conclusions In CREDO, the efficacy of clopidogrel was not significantly affected by PPI use. However, in CAPRIE, clopidogrel was beneficial to non‐PPI users while apparently harmful to PPI users. Whether this negative interaction is clinically important for patients receiving clopidogrel without aspirin needs further study. PMID:23525436

  1. Time esophageal pH < 4 overestimates the prevalence of pathologic esophageal reflux in subjects with gastroesophageal reflux disease treated with proton pump inhibitors

    Directory of Open Access Journals (Sweden)

    Sloan Sheldon

    2008-05-01

    Full Text Available Abstract Background A Stanford University study reported that in asymptomatic GERD patients who were being treated with a proton pump inhibitor (PPI, 50% had pathologic esophageal acid exposure. Aim We considered the possibility that the high prevalence of pathologic esophageal reflux might simply have resulted from calculating acidity as time pH Methods We calculated integrated acidity and time pH Results The prevalence of pathologic 24-hour esophageal reflux in both studies was significantly higher when measured as time pH Conclusion In GERD subjects treated with a PPI, measuring time esophageal pH

  2. Malignant Range Elevation of Serum Chromogranin A due to Inadvertent Use of Proton Pump Inhibitor in a Subject with Pancreatic Incidentaloma

    Directory of Open Access Journals (Sweden)

    Usman Hammawa Malabu

    2011-01-01

    Full Text Available We present a case of highly elevated tenfold rise of serum chromogranin A in a young, morbidly obese, hypertensive female being investigated for pancreatic mass, weight loss, and elevated ESR. Following extensive noninvasive investigations, an ultrasound-guided pancreatic biopsy confirmed benign haemorrhagic cyst. A clue to the etiology of the hyperchromogranin A was the elevated serum gastrin level leading to suspicion of proton pump inhibitor administration confirmed by admittance to its use. Withdrawal of the medication led to dramatic resolution of the neuroendocrine tumor marker.

  3. Impact of proton pump inhibitor treatment on gastrointestinal bleeding associated with non-steroidal anti-inflammatory drug use among post-myocardial infarction patients taking antithrombotics

    DEFF Research Database (Denmark)

    Olsen, A. M. S.; Lindhardsen, J.; Gislason, G. H.

    2015-01-01

    STUDY QUESTION What is the effect of proton pump inhibitors (PPIs) on the risk of gastrointestinal bleeding in post-myocardial infarction patients taking antithrombotics and treated with non-steroidal anti-inflammatory drugs (NSAIDs)? METHODS This was a nationwide cohort study based on linked...... plus antithrombotic therapy was estimated using adjusted time dependent Cox regression models. STUDY ANSWER AND LIMITATIONS The use of PPIs was independently associated with decreased risk of gastrointestinal bleeding in post-myocardial infarction patients taking antithrombotics and treated with NSAIDs...

  4. Characterization and partial purification of a proton translocating ATPase from corn coleoptile tonoplasts

    Energy Technology Data Exchange (ETDEWEB)

    Mandala, S.M.

    1985-01-01

    ATP-dependent proton translocating activity in microsomal membranes from corn coleoptiles was characterized. Proton pumping activity, detected by either /sup 14/C-methylamine uptake or quinacrine fluorescence quenching, had a broad optimum at pH 7.5, and was substrate specific for MgATP. N,N'-dicyclohexylcarbodiimide, diethylstilbestrol, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, and protonophores were found to inhibit proton transport, while vanadate and oligomycin had little effect. Proton pumping activity was stimulated 10 fold with Cl/sup -/ but was almost completely inhibited by 50 mM, KNO/sub 3/. Uptake studies with /sup 36/Cl/sup -/ indicated the Cl/sup -/ was transported into the microsomal vesicles in response to the pH gradient. ATP-stimulated proton pumping activity was localized on linear density gradients. On sucrose gradients, the activity cosedimented with the marker for endoplasmic reticulum at 1.11 g/cc. Sucrose gradients prepared in the presence of MgCl/sub 2/ were used to shift the ER marker to a heavier density, away from proton pumping activity. Linear dextran gradients also resulted in a clear separation of ATP-stimulated methylamine, thiocyanate, and /sup 36/Cl/sup -/ uptake, from markers for ER, Golgi, mitochondria, and plasma membranes. The tonoplast ATPase was solubilized with octylglucoside and partially purified on linear sucrose gradients. The specific activity of the KNO/sub 3/-sensitive ATPase increased 30-fold during purification.

  5. Proton pump activity is required for active uptake of chloride in isolated amphibian skin exposed to freshwater

    DEFF Research Database (Denmark)

    Jensen, Lars Jørn; Willumsen, Niels J.; Larsen, Erik Hviid

    2002-01-01

    Net proton secretion and unidirectional chloride fluxes were measured in isolated skin of toads (Bufo bufo) and frogs (Rana esculenta) mounted in an Ussing chamber and exposed to a Ringer's solution on the serosal side and a freshwater-like solution (1-3 mM Cl-) on the external side. Active proto...

  6. Long-term use of Proton Pump Inhibitors, Dose-response Relationship, and Associated Risk of Ischemic Stroke and Myocardial Infarction

    DEFF Research Database (Denmark)

    Sehested, Thomas S G; Gerds, Thomas A; Fosbøl, Emil L

    2018-01-01

    Danish individuals with no prior history of MI or stroke, who had an elective upper gastrointestinal endoscopy performed between 1997 and 2012, were identified from nationwide registries. We used multiple Poisson regression to test associations with current PPI use and its dose, and used multiple cause......BACKGROUND: Use of proton pump inhibitors (PPIs) has been associated with cardiovascular disease among patients not on antiplatelet therapy. The associations of PPI use, duration and dose, with risk of first-time ischemic stroke and myocardial infarction (MI) are poorly understood. METHODS: All....... CONCLUSION: Use of PPIs was associated with increased risks of first-time ischemic stroke and MI, particularly among long-term users and at high doses. This article is protected by copyright. All rights reserved....

  7. Intravenous versus high-dose oral proton pump inhibitor therapy after endoscopic hemostasis of high-risk lesions in patients with acute nonvariceal upper gastrointestinal bleeding.

    Science.gov (United States)

    Murthy, Sanjay; Keyvani, Leila; Leeson, Shauna; Targownik, Laura E

    2007-07-01

    Intravenous proton pump inhibitors (IV PPIs) decrease rebleeding following endoscopic hemostasis of bleeding peptic ulcers. Oral PPIs may be equally efficacious and may significantly reduce health care costs. This study aimed to compare outcomes in patients receiving oral versus IV PPI therapy following endoscopic hemostasis in patients with acute nonvariceal upper gastrointestinal bleeding (ANVUGIB). We performed a retrospective review of all patients who received PPI therapy following endoscopic hemostasis for ANVUGIB. The primary outcome was the adverse gastrointestinal event rate. One hundred sixty-two patients met the entry criteria (72 oral PPIs, 90 IV PPIs). The difference in the rate of adverse gastrointestinal events between the two groups was 1% (P = 0.85). Postendoscopic IV PPI use was associated with an odds ratio of 1.01 for developing an adverse outcome versus oral PPIs (95% CI: 0.44-2.33). We conclude that oral PPIs are probably equivalent to IV PPIs for preventing rebleeding in ANVUGIB patients.

  8. Negative Effect of Proton-pump Inhibitors (PPIs) on Helicobacter pylori Growth, Morphology, and Urease Test and Recovery after PPI Removal--An In vitro Study.

    Science.gov (United States)

    Saniee, Parastoo; Shahreza, Somayeh; Siavoshi, Farideh

    2016-04-01

    Proton-pump inhibitor (PPI) consumption does lead to false-negative results of Helicobacter pylori diagnostic tests such as biopsy culture and rapid urease test (RUT). Helicobacter pylori isolates from 112 dyspeptic patients with (56.5%) or without (43.5%) PPI consumption were recruited for examining the negative effects of omeprazole (OMP), lansoprazole (LPZ), and pantoprazole (PAN) on H. pylori viability, morphology, and urease, in vitro. The effect of a sublethal concentration of OMP on bacterial features and their recovery after removal of OMP was also assessed. Of 112 culture-positive gastric biopsies, 87.5% were RUT positive and 12.5% RUT negative. There was a significant correlation between negative RUT results and PPI consumption (p pylori isolates. OMP and LPZ inhibited urease of 90.3% of isolates between 0 and 40 minutes and 54.4% between 20 and 40 minutes, respectively. PAN did not inhibit H. pylori growth and urease. Three 3-day (9 days) consecutive subcultures of H. pylori on brucella blood agar (BBA) supplemented with OMP resulted in reduced bacterial viability (1+), compared with control (4+), change of spiral morphology to coccoid, and reduction in pink color intensity in urea agar. Bacterial growth (1+), morphology, and urease test did not improve after the first 3-day and second 3-day (6 days) subcultures on BBA. However, relative recovery occurred after the third 3-day (9 days) subculture and complete recovery was observed after the fourth 3-day (12 days) subculture, as confluent growth (4+), 100% spiral cells, and strong urease test. Proton-pump Inhibitors exert transient negative effects on H. pylori viability, morphology, and urease test. Accordingly, cessation of PPI consumption at least 12 days before endoscopy could help avoiding false-negative results of H. pylori diagnostic tests. © 2015 John Wiley & Sons Ltd.

  9. Ten-day Quadruple therapy comprising proton-pump inhibitor, bismuth, tetracycline, and levofloxacin achieves a high eradication rate for Helicobacter pylori infection after failure of sequential therapy.

    Science.gov (United States)

    Hsu, Ping-I; Chen, Wen-Chi; Tsay, Feng-Woei; Shih, Chih-An; Kao, Sung-Shuo; Wang, Huay-Min; Yu, Hsien-Chung; Lai, Kwok-Hung; Tseng, Hui-Hwa; Peng, Nan-Jing; Chen, Angela; Kuo, Chao-Hung; Wu, Deng-Chyang

    2014-02-01

    Sequential therapy has been recommended in the Maastricht IV/Florence Consensus Report as the first-line treatment for Helicobacter pylori eradication in regions with high clarithromycin resistance. However, it fails in 5-24% of infected subjects, and the recommended levofloxacin-containing triple rescue therapy only achieves a 77% eradication rate after failure of sequential therapy. To investigate the efficacy of a novel quadruple therapy comprising proton-pump inhibitor, bismuth, tetracycline, and levofloxacin for rescue treatment of sequential therapy. This was a multicenter study in which H. pylori-infected patients who had failed sequential therapy received a 10-day quadruple therapy (esomeprazole (40 mg b.d), tripotassium dicitrato bismuthate (120 mg q.d.s.), tetracycline (500 mg q.d.s.), and levofloxacin (500 mg o.d.) for 10 days). H. pylori status was examined 6 weeks after the end of treatment. From July 2007 to June 2012, twenty-four subjects received 10-day quadruple therapy. The eradication rates according to intention-to-treat and per-protocol analyses were both 95.8% (23 of 24; 95% confidence interval, 87.8-103.8%). Adverse events were seen in 25.0% (6 of 24) of the patients. Drug compliance was 100.0% (24/24). The 10-day quadruple therapy comprising proton-pump inhibitor, bismuth, tetracycline, and levofloxacin achieves a very high eradication rate for H. pylori infection after failure of sequential therapy. It is well tolerated and has great potential to become a good choice of rescue treatment following non-bismuth-containing quadruple therapy in regions with high clarithromycin resistance. © 2013 John Wiley & Sons Ltd.

  10. A Genetic Screen for Pathogenicity Genes in the Hemibiotrophic Fungus Colletotrichum higginsianum Identifies the Plasma Membrane Proton Pump Pma2 Required for Host Penetration.

    Science.gov (United States)

    Korn, Martin; Schmidpeter, Johannes; Dahl, Marlis; Müller, Susanne; Voll, Lars M; Koch, Christian

    2015-01-01

    We used insertional mutagenesis by Agrobacterium tumefaciens mediated transformation (ATMT) to isolate pathogenicity mutants of Colletotrichum higginsianum. From a collection of 7200 insertion mutants we isolated 75 mutants with reduced symptoms. 19 of these were affected in host penetration, while 17 were affected in later stages of infection, like switching to necrotrophic growth. For 16 mutants the location of T-DNA insertions could be identified by PCR. A potential plasma membrane H(+)-ATPase Pma2 was targeted in five independent insertion mutants. We genetically inactivated the Ku80 component of the non-homologous end-joining pathway in C. higginsianum to establish an efficient gene knockout protocol. Chpma2 deletion mutants generated by homologous recombination in the ΔChku80 background form fully melanized appressoria but entirely fail to penetrate the host tissue and are non-pathogenic. The ChPMA2 gene is induced upon appressoria formation and infection of A. thaliana. Pma2 activity is not important for vegetative growth of saprophytically growing mycelium, since the mutant shows no growth penalty under these conditions. Colletotrichum higginsianum codes for a closely related gene (ChPMA1), which is highly expressed under most growth conditions. ChPMA1 is more similar to the homologous yeast genes for plasma membrane pumps. We propose that expression of a specific proton pump early during infection may be common to many appressoria forming fungal pathogens as we found ChPMA2 orthologs in several plant pathogenic fungi.

  11. Relating proton pumps with gap junctions: colocalization of ductin, the channel-forming subunit c of V-ATPase, with subunit a and with innexins 2 and 3 during Drosophila oogenesis.

    Science.gov (United States)

    Lautemann, Julia; Bohrmann, Johannes

    2016-07-13

    separately concentrated in presumed gap-junction plaques. Our results support the notion of a large variety of gap junctions existing in the Drosophila ovary. Moreover, since ductin is the channel-forming part of a proton pump and, like the innexins, is able to form junctional as well as non-junctional membrane channels, a plethora of cellular functions could be realized by using these proteins. The distribution and activity patterns of such membrane channels are expected to contribute to developmentally important bioelectric signals.

  12. Proton pump inhibitors suppress iNOS-dependent DNA damage in Barrett's esophagus by increasing Mn-SOD expression

    Energy Technology Data Exchange (ETDEWEB)

    Thanan, Raynoo [Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Mie 513-8670 (Japan); Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507 (Japan); Ma, Ning [Faculty of Health Science, Suzuka University of Medical Science, Suzuka, Mie 513-0293 (Japan); Iijima, Katsunori; Abe, Yasuhiko; Koike, Tomoyuki; Shimosegawa, Tooru [Division of Gastroenterology, Tohoku University Hospital, Sendai, Miyaki 980-8574 (Japan); Pinlaor, Somchai [Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen 40002 (Thailand); Hiraku, Yusuke; Oikawa, Shinji; Murata, Mariko [Department of Environmental and Molecular Medicine, Mie University Graduate School of Medicine, Tsu, Mie 514-8507 (Japan); Kawanishi, Shosuke, E-mail: kawanisi@suzuka-u.ac.jp [Faculty of Pharmaceutical Sciences, Suzuka University of Medical Science, Suzuka, Mie 513-8670 (Japan)

    2012-05-04

    Highlights: Black-Right-Pointing-Pointer Inflammation by Barrett's esophagus (BE) is a risk factor of its adenocarcinoma (BEA). Black-Right-Pointing-Pointer 8-Nitroguanine and 8-oxodG are inflammation-related DNA lesions. Black-Right-Pointing-Pointer DNA lesions and iNOS expression were higher in the order, BEA > BE > normal tissues. Black-Right-Pointing-Pointer Proton pump inhibitors suppress DNA damage by increasing Mn-SOD via Nrf2 activation. Black-Right-Pointing-Pointer DNA lesions can be useful biomarkers to predict risk of BEA in BE patients. -- Abstract: Barrett's esophagus (BE), an inflammatory disease, is a risk factor for Barrett's esophageal adenocarcinoma (BEA). Treatment of BE patients with proton pump inhibitors (PPIs) is expected to reduce the risk of BEA. We performed an immunohistochemical study to examine the formation of nitrative and oxidative DNA lesions, 8-nitroguanine and 8-oxo-7,8-dihydro-2 Prime -deoxygaunosine (8-oxodG), in normal esophageal, BE with pre- and post-treatment by PPIs and BEA tissues. We also observed the expression of an oxidant-generating enzyme (iNOS) and its transcription factor NF-{kappa}B, an antioxidant enzyme (Mn-SOD), its transcription factor (Nrf2) and an Nrf2 inhibitor (Keap1). The immunoreactivity of DNA lesions was significantly higher in the order of BEA > BE > normal tissues. iNOS expression was significantly higher in the order of BEA > BE > normal tissues, while Mn-SOD expression was significantly lower in the order of BEA < BE < normal tissues. Interestingly, Mn-SOD expression and the nuclear localization of Nrf2 were significantly increased, and the formation of DNA lesions was significantly decreased in BE tissues after PPIs treatment for 3-6 months. Keap1 and iNOS expression was not significantly changed by the PPIs treatment in BE tissues. These results indicate that 8-nitroguanine and 8-oxodG play a role in BE-derived BEA. Additionally, PPIs treatment may trigger the activation and

  13. Comparison of health care resource utilization and costs among patients with GERD on once-daily or twice-daily proton pump inhibitor therapy

    Directory of Open Access Journals (Sweden)

    Mody R

    2013-04-01

    Full Text Available Reema Mody,1 Debra Eisenberg,2 Likun Hou,2 Siddhesh Kamat,2 Joseph Singer,2 Lauren B Gerson3 1Takeda Pharmaceuticals International Inc, Deerfield, IL, 2HealthCore Inc, Wilmington, DE, 3Stanford University School of Medicine, Stanford, CA, USA Background: The purpose of this study was to assess differences in health care resource utilization and costs associated with once-daily and twice-daily proton pump inhibitor (PPI therapy. Most patients with gastroesophageal reflux disease (GERD achieve symptom control on once-daily PPI therapy, but approximately 20%–30% require twice-daily dosing. Methods: Patients were ≥18 years of age with at least one medical claim for GERD and at least two PPI claims from HealthCore's Integrated Research Database (HIRDSM during 2004–2009. Patients were continuously eligible for 12 months before and after the index date (date of first PPI claim. Based on PPI dosing throughout the post-index period (quantity of medication dispensed/number of days supply, patients were classified as once-daily (dose ≤ 1.5 pills per day or twice-daily (≥1.5 PPI users. Results: The study cohort included 248,386 patients with GERD (mean age 52.8 ± 13.93 years, 56% females of whom 90% were once-daily and 10% were twice-daily PPI users. The Deyo-Charlson Comorbidity Index for once-daily and twice-daily PPI users was 0.70 ± 1.37 and 0.89 ± 1.54, respectively (P < 0.05. More once-daily patients had claims for Barrett's esophagus (5% versus 2%, P < 0.0001 than twice-daily patients. Post-index, higher proportions of twice-daily patients had at least one GERD-related inpatient visit (7% versus 5%, outpatient visit (60% versus 49%, and office visit (48% versus 38% versus once-daily patients (P < 0.0001. Mean total GERD-related health care costs were $2065 ± $6636 versus $3749 ± $11,081 for once-daily and twice-daily PPI users, respectively (P < 0.0001. Conclusion: Patients receiving twice-daily PPI therapy were likely to have more

  14. Outcomes in patients with nonerosive reflux disease treated with a proton pump inhibitor and alginic acid ± glycyrrhetinic acid and anthocyanosides

    Directory of Open Access Journals (Sweden)

    Di Pierro F

    2013-03-01

    Full Text Available Francesco Di Pierro,1 Mario Gatti,2 Giuliana Rapacioli,3 Leandro Ivaldi4 1Velleja Research, Milan, 2Gastroenterology Department, Giussano Hospital, Monza-Brianza, 3AIOR, Piacenza, 4Digestive Endoscopic Department, Ceva Hospital, Ceva, Cuneo, Italy Background: The purpose of this study was to compare the efficacy of alginic acid alone versus alginic acid combined with low doses of pure glycyrrhetinic acid and bilberry anthocyanosides as an addon to conventional proton pump inhibitor therapy in relieving symptoms associated with nonerosive reflux disease. Methods: This prospective, randomized, 8-week, open-label trial was conducted at two centers. Sixty-three patients with persistent symptoms of gastroesophageal reflux disease and normal upper gastrointestinal endoscopy were eligible for the study. Patients in group A (n = 31 were treated with pantoprazole and a formula (Mirgeal® containing alginic acid and low doses of pure glycyrrhetinic acid + standardized Vaccinium myrtillus extract for 4 weeks, then crossed over to the multi-ingredient formula for a further 4 weeks. Patients in group B (n = 32 were treated pantoprazole and alginic acid alone twice daily, then crossed over to alginic acid twice daily for a further 4 weeks. Efficacy was assessed by medical evaluation of a symptom relief score, estimated using a visual analog scale (0–10. Side effects, tolerability, and compliance were also assessed. Results: Of the 63 patients enrolled in the study, 58 (29 in group A and 29 in group B completed the 8-week trial. The baseline characteristics were comparable between the two groups. During the study, significant differences were recorded in symptom scores for both groups. In group A, symptoms of chest pain, heartburn, and abdominal swelling were less serious than in group B. Treatment A was better tolerated, did not induce hypertension, and had fewer side effects than treatment B. No significant differences in compliance were found between the

  15. Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles.

    Science.gov (United States)

    Farsi, Zohreh; Preobraschenski, Julia; van den Bogaart, Geert; Riedel, Dietmar; Jahn, Reinhard; Woehler, Andrew

    2016-02-26

    Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided by an electrochemical proton gradient. However, it is unclear how transmitter molecules carrying different net charges can be efficiently sequestered while maintaining charge neutrality and osmotic balance. We used single-vesicle imaging to monitor pH and electrical gradients and directly showed different uptake mechanisms for glutamate and γ-aminobutyric acid (GABA) operating in parallel. In contrast to glutamate, GABA was exchanged for protons, with no other ions participating in the transport cycle. Thus, only a few components are needed to guarantee reliable vesicle filling with different neurotransmitters. Copyright © 2016, American Association for the Advancement of Science.

  16. The effectiveness of prophylactic proton pump inhibitors for prevention of non-steroidal anti inflammatory drugs associated gastric and duodenal ulcers in elderly.

    Science.gov (United States)

    Kheiri, Babikir; Mabrouk, Ahmed; Ahmed, Imran; Khan, Hashim; Sheikh, Azeem S

    2014-01-01

    Aims was undertaken to ensure concomitant usage of proton pump inhibitors (PPIs) with Non-Steroidal Anti-inflammatory Drugs (NSAIDs) in Elderly, in order to avoid upper gastrointestinal (GI) symptoms and ulcers. Reviewing of 386 patients' prescription on the EMIS (Egton Medical Information Systems) Web, on April 2014. Checking who have not been prescribed PPIs with NSAIDs, offering them appointment for prescription and discussion about risks and benefits of PPIs. Re-audit of 390 patients' prescription on the EMIS Web, on July 2014. Exclusion criteria in the audit and re-audit were; NSAIDs usage for more than 3 years, contra-indications for PPIs, and patients who declined inclusion in the audit. In the first audit cycle, a total of 386 patients' prescription reviewed, 23 (6%) patients were not prescribed PPIs with NSAIDs and were eligible for PPIs prescription. Those patients were contacted by post, an appointment arranged for them and prescribed the PPIs. 12 weeks later a re-audit was done, showed that all patients (100%) who are prescribed NSAIDs are prescribed prophylactic PPIs. None of the patients who are prescribed NSAIDs and PPIs concomitantly developed upper GI symptoms or ulcers. The audit increased the awareness of the junior doctors of the importance of concomitant prescription of PPIs with NSAIDs, in accordance with the electronic Medical Compendium (eMC) guidelines, to prevent upper GI symptoms and ulcers. That was reflected in the re-audit having 100% of the patients prescribed NSAIDs and PPIs concomitantly.

  17. Adenocarcinoma arising in multiple hyperplastic polyps in a patient with Helicobacter pylori infection and hypergastrinemia during long-term proton pump inhibitor therapy.

    Science.gov (United States)

    Anjiki, Hajime; Mukaisho, Ken-Ichi; Kadomoto, Yu; Doi, Hisakazu; Yoshikawa, Kunio; Nakayama, Takahisa; Vo, Diem Thi-Ngoc; Hattori, Takanori; Sugihara, Hiroyuki

    2017-04-01

    We report a case of developing multiple adenocarcinoma foci in multiple hyperplastic polyps in a patient with Helicobacter pylori infection and hypergastrinemia during long-term proton pump inhibitor (PPI) therapy. A 57-year-old man, who was undergoing hemodialysis for chronic renal failure, underwent an upper gastrointestinal endoscopy to elucidate the cause of anemia. Atrophic gastritis with H. pylori infection and multiple adenocarcinoma foci in multiple hyperplastic polyps were found in the endoscopic and histological examinations. Enterochromaffin-like micronests and parietal cell protrusion in the background of the polyps suggested the existence of hypergastrinemia. The serum gastrin level was markedly high-10,206 pg/ml (normal range 37-172 pg/ml). The cause of this marked hypergastrinemia was not autoimmune gastritis and gastrinoma. After discontinuing PPI therapy and successful eradication of H. pylori, the serum gastrin level decreased to normal range. These findings indicate that hypergastrinemia may be caused by long-term PPI therapy in patients with H. pylori infection. This case suggests that hypergastrinemia may mediate gastric carcinogenesis in patients with H. pylori infection.

  18. Extraesophageal Reflux: What Is the Best Parameter for pH-Monitoring Data Analysis from the Perspective of Patient Response to Proton Pump Inhibitors?

    Directory of Open Access Journals (Sweden)

    Karol Zelenik

    2013-01-01

    Full Text Available Objectives. To analyze the pH-monitoring records of patients with suspected extraesophageal reflux (EER using three different parameters (number of refluxes (NOR, acid exposure time (AET, and reflux area index (RAI, with a view to determining which type of analysis is best at selecting the patients who will respond to a proton pump inhibitor (PPI. Methods. Demographic data were obtained and the level of the complaint was assessed using the Visual Analogue Scale. A dual probe pH-monitoring study was conducted. NOR greater than six, AET more than 0.1%, and RAI higher than 6.3 mpH were taken to be the thresholds for EER. Subsequently the response to a 12-week PPI trial was analyzed. Results. A total of 81 patients were analyzed. The percentages of patients with substantial EER based on NOR, AET, and RAI were 36%, 28% and 26%, respectively. Statistically significant, often positive PPI trials were confirmed in the group identified as having substantial EER using all three types of analysis. When using AET and RAI, the significance was more pronounced (P=0.012 and P=0.013, resp. in comparison with NOR (P=0.033. Conclusions. Patients with EER diagnosed using AET or RAI will respond to PPI significantly often.

  19. Correlation between the Serum Pepsinogen I Level and the Symptom Degree in Proton Pump Inhibitor-Users Administered with a Probiotic

    Directory of Open Access Journals (Sweden)

    Muneki Igarashi

    2014-06-01

    Full Text Available In patients with functional upper gastrointestinal disorders such as gastroesophageal reflux disease and functional dyspepsia, the presence of symptoms is thought to occur in the absence of any organic diseases and the mechanisms behind this remain unclear. We therefore examined the relationship between stomach-related biomarker levels and symptoms. Twenty-four outpatients who had taken proton-pump inhibitors every day were enrolled in this study. The subjects consumed yogurt containing 109 colony-forming units of Lactobacillus gasseri OLL2716 (LG21 every day for three months. They underwent four clinical examinations in total. Each examination consisted of answering a questionnaire with a frequency scale for the symptoms of GERD (FSSG, and included measurements of the serum gastrin, ghrelin, and pepsinogens I and II levels. As a result, the FSSG score and the PGI value showed a decrease and an increase, respectively, after LG21 treatment when analyzed without age adjustment. A multiple regression analysis with additional adjustments for gender and age revealed a strong association between the PGI value and the FSSG symptom scores. Therefore either the PGI level itself or the factors regulating the PGI level might be involved in the etiology of these symptoms.

  20. Influence of proton-pump inhibitors on stomach wall uptake of 99mTc-tetrofosmin in cadmium-zinc-telluride SPECT myocardial perfusion imaging.

    Science.gov (United States)

    Mouden, Mohamed; Rijkee, Karlijn S; Schreuder, Nanno; Timmer, Jorik R; Jager, Pieter L

    2015-02-01

    Proton-pump inhibitors (PPIs) induce potentially interfering stomach wall activity in single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) with technetium-99m ((99m)Tc)-sestamibi. However, no data are available for (99m)Tc-tetrofosmin. We assessed the influence of prolonged (>2 weeks) PPI use on the stomach wall uptake of (99m)Tc-tetrofosmin in patients referred for stress MPI with a cadmium-zinc-telluride-based SPECT camera and its relation with dyspepsia symptoms. Consecutive patients (n=127) underwent a 1-day adenosine stress-first SPECT-MPI with (99m)Tc-tetrofosmin, of whom 54 (43%) patients had been on PPIs for more than 2 weeks. Stomach wall activity was identified on stress SPECT using computed tomographic attenuation maps and was scored using a four-point grading scale into clinically relevant (scores 2 or 3) or nonrelevant (scores 0 or 1).Patients on PPIs had stomach wall uptake more frequently as compared with patients not using PPIs (22 vs. 7%, P=0.017). Dyspepsia was similar in both groups. Prolonged use of PPIs is associated with stomach wall uptake of (99m)Tc-tetrofosmin in stress cadmium-zinc-telluride-SPECT images. Gastric symptoms were not associated with stomach wall uptake.

  1. Proton pump inhibitor use for 12 months is not associated with changes in serum magnesium levels: a prospective open label comparative study.

    Science.gov (United States)

    Bahtiri, Elton; Islami, Hilmi; Hoxha, Rexhep; Gashi, Afrim; Thaçi, Kujtim; Karakulak, Çağla; Thaçi, Shpetim; Qorraj Bytyqi, Hasime

    2017-03-01

    Proton pump inhibitors (PPIs) are a widely used class of drugs because of a generally acceptable safety profile. Among recently raised safety issues of the long-term use of PPIs is the increased risk of developing hypomagnesemia. As there have been very few prospective studies measuring serum magnesium levels before and after PPI therapy, we aimed to prospectively assess the potential association between PPI therapy for 12 months and the risk of hypomagnesemia as well as the incidence of new-onset hypomagnesemia during the study. In addition, the association of PPI therapy with the risk of hypocalcemia was assessed. The study included 250 patients with normal serum magnesium and total calcium levels, who underwent a long-term PPI treatment. Serum magnesium, total calcium, and parathormone (PTH) levels were measured at baseline and after 12 months. Of the 250 study participants, 209 completed 12 months of treatment and were included in the statistical analysis. The Wilcoxon signed rank test showed no statistically significant differences in serum magnesium levels between measurements at two different time points. However, there were statistically significant differences in serum total calcium and PTH levels in PPI users. Stable serum magnesium levels were demonstrated after 12 months and no association between PPI use and risk of hypomagnesemia was shown in the general population. Significant reductions of serum total calcium levels were demonstrated among PPI users; nevertheless, further research is required before recommending any serum calcium and PTH level monitoring in patients initiated on long-term PPI therapy.

  2. Additive Effects of Rebamipide Plus Proton Pump Inhibitors on the Expression of Tight Junction Proteins in a Rat Model of Gastro-Esophageal Reflux Disease.

    Science.gov (United States)

    Gweon, Tae-Geun; Park, Jong-Hyung; Kim, Byung-Wook; Choi, Yang Kyu; Kim, Joon Sung; Park, Sung Min; Kim, Chang Whan; Kim, Hyung-Gil; Chung, Jun-Won

    2017-10-27

    The aim of this study was to investigate the effects of rebamipide on tight junction proteins in the esophageal mucosa in a rat model of gastroesophageal reflux disease (GERD). GERD was created in rats by tying the proximal stomach. The rats were divided into a control group, a proton pump inhibitor (PPI) group, and a PPI plus rebamipide (PPI+R) group. Pantoprazole (5 mg/kg) was administered intraperitoneally to the PPI and PPI+R groups. An additional dose of rebamipide (100 mg/kg) was administered orally to the PPI+R group. Mucosal erosions, epithelial thickness, and leukocyte infiltration into the esophageal mucosa were measured in isolated esophagi 14 days after the procedure. A Western blot analysis was conducted to measure the expression of claudin-1, -3, and -4. The mean surface area of mucosal erosions, epithelial thickness, and leukocyte infiltration were lower in the PPI group and the PPI+R group than in the control group. Western blot analysis revealed that the expression of claudin-3 and -4 was significantly higher in the PPI+R group than in the control group. Rebamipide may exert an additive effect in combination with PPI to modify the tight junction proteins of the esophageal mucosa in a rat model of GERD. This treatment might be associated with the relief of GERD symptoms.

  3. Is the Ca2+-ATPase from sarcoplasmic reticulum also a heat pump?

    Science.gov (United States)

    Kjelstrup, Signe; de Meis, Leopoldo; Bedeaux, Dick; Simon, Jean-Marc

    2008-11-01

    We calculate, using the first law of thermodynamics, the membrane heat fluxes during active transport of Ca(2+) in the Ca(2+)-ATPase in leaky and intact vesicles, during ATP hydrolysis or synthesis conditions. The results show that the vesicle interior may cool down during hydrolysis and Ca(2+)-uptake, and heat up during ATP synthesis and Ca(2+)-efflux. The heat flux varies with the SERCA isoform. Electroneutral processes and rapid equilibration of water were assumed. The results are consistent with the second law of thermodynamics for the overall processes. The expression for the heat flux and experimental data, show that important contributions come from the enthalpy of hydrolysis for the medium in question, and from proton transport between the vesicle interior and exterior. The analysis give quantitative support to earlier proposals that certain, but not all, Ca(2+)-ATPases, not only act as Ca(2+)-pumps, but also as heat pumps. It can thus help explain why SERCA 1 type enzymes dominate in tissues where thermal regulation is important, while SERCA 2 type enzymes, with their lower activity and better ability to use the energy from the reaction to pump ions, dominate in tissues where this is not an issue.

  4. Proton-pump inhibitors adverse effects: a review of the evidence and position statement by the Sociedad Española de Patología Digestiva.

    Science.gov (United States)

    de la Coba Ortiz, Cristóbal; Argüelles Arias, Federico; Martín de Argila de Prados, Carlos; Júdez Gutiérrez, Javier; Linares Rodríguez, Antonio; Ortega Alonso, Aida; Rodríguez de Santiago, Enrique; Rodríguez-Téllez, Manuel; Vera Mendoza, María Isabel; Aguilera Castro, Lara; Álvarez Sánchez, Ángel; Andrade Bellido, Raúl Jesús; Bao Pérez, Fidencio; Castro Fernández, Manuel; Giganto Tomé, Froilán

    2016-04-01

    In the last few years a significant number of papers have related the use of proton-pump inhibitors (PPIs) to potential serious adverse effects that have resulted in social unrest. The goal of this paper was to provide a literature review for the development of an institutional position statement by Sociedad Española de Patología Digestiva (SEPD) regarding the safety of long-term PPI use. A comprehensive review of the literature was performed to draw conclusions based on a critical assessment of the following: a) current PPI indications; b) vitamin B12 deficiency and neurological disorders; c) magnesium deficiency; d) bone fractures; e) enteric infection and pneumonia; f) interactions with thienopyridine derivatives; e) complications in cirrhotic patients. Current PPI indications have remained unchanged for years now, and are well established. A general screening of vitamin B12 levels is not recommended for all patients on a PPI; however, it does seem necessary that magnesium levels be measured at therapy onset, and then monitored in subjects on other drugs that may induce hypomagnesemia. A higher risk for bone fractures is present, even though causality cannot be concluded for this association. The association between PPIs and infection with Clostridium difficile is mild to moderate, and the risk for pneumonia is low. In patients with cardiovascular risk receiving thienopyridines derivatives it is prudent to adequately consider gastrointestinal and cardiovascular risks, given the absence of definitive evidence regardin potential drug-drug interactions; if gastrointestinal risk is found to be moderate or high, effective prevention should be in place with a PPI. PPIs should be cautiously indicated in patients with decompensated cirrhosis. PPIs are safe drugs whose benefits outweigh their potential side effects both short-term and long-term, provided their indication, dosage, and duration are appropriate.

  5. Proton-pump inhibitors adverse effects: a review of the evidence and position statement by the Sociedad Española de Patología Digestiva

    Directory of Open Access Journals (Sweden)

    Cristóbal de-la-Coba

    2016-04-01

    Full Text Available Introduction: In the last few years a significant number of papers have related the use of proton-pump inhibitors (PPIs to potential serious adverse effects that have resulted in social unrest. Objective: The goal of this paper was to provide a literature review for the development of an institutional position statement by Sociedad Española de Patología Digestiva (SEPD regarding the safety of long-term PPI use. Material and methods: A comprehensive review of the literature was performed to draw conclusions based on a critical assessment of the following: a current PPI indications; b vitamin B12 deficiency and neurological disorders; c magnesium deficiency; d bone fractures; e enteric infection and pneumonia; f interactions with thienopyridine derivatives; e complications in cirrhotic patients. Results: Current PPI indications have remained unchanged for years now, and are well established. A general screening of vitamin B12 levels is not recommended for all patients on a PPI; however, it does seem necessary that magnesium levels be measured at therapy onset, and then monitored in subjects on other drugs that may induce hypomagnesemia. A higher risk for bone fractures is present, even though causality cannot be concluded for this association. The association between PPIs and infection with Clostridium difficile is mild to moderate, and the risk for pneumonia is low. In patients with cardiovascular risk receiving thienopyridines derivatives it is prudent to adequately consider gastrointestinal and cardiovascular risks, given the absence of definitive evidence regardin potential drug-drug interactions; if gastrointestinal risk is found to be moderate or high, effective prevention should be in place with a PPI. PPIs should be cautiously indicated in patients with decompensated cirrhosis. Conclusions: PPIs are safe drugs whose benefits outweigh their potential side effects both short-term and long-term, provided their indication, dosage, and

  6. Changes in gastric pH and in pharmacokinetics of ulipristal acetate - a drug-drug interaction study using the proton pump inhibitor esomeprazole.

    Science.gov (United States)

    Pohl, Oliver; Osterloh, Ian; Lecomte, Véronique; Gotteland, Jean-Pierre

    2013-01-01

    Ulipristal acetate is a novel selective progesterone receptor modulator for the treatment of benign gynecological conditions such as uterine myoma. As a Biopharmaceutical Classification System (BCS) II compound, it is highly soluble at low pH but has low solubility at neutral conditions. Esomeprazole, a proton pump inhibitor used widely for treatment of gastric and duodenal ulcers, efficiently increases gastric pH. Thus, the aim of this study was to determine the effects of esomeprazole on the pharmacokinetics of ulipristal acetate. This was a nonrandomized, single sequence, 2 period, open, study in 18 healthy female subjects. Subjects received oral ulipristal acetate tablets (10 mg) once on Days 1 and 13 and daily esomeprazole administrations (20 mg) from Days 9 through 14. Co-administration of esomeprazole decreased geometric mean Cmax of ulipristal acetate by 65% (geometric mean ratio point estimate (90% CI): 0.35 (0.28 - 0.42)), and delayed median tmax from 0.75 to 1.00 h (Hodges-Lehmann estimate of difference (90% CI): tmax 0.63 (0.25 - 1.25)) but had minor effects on AUCs of +15% and +11% (geometric mean ratio point estimates (90% CI): AUC0-t 1.15 (1.02 - 1.31) and AUC0-∞ (1.11 (0.98 - 1.27)), respectively. A total of 6 adverse events were reported by 4 subjects, none of them being serious. Concomitant use of ulipristal acetate with esomeprazole at therapeutic concentrations led to a modified absorption rate while exposure in terms of AUC remained close to bioequivalence limits. In the context of chronic administration of ulipristal acetate, no clinically significant effects are expected from co-administration with drugs increasing gastric pH.

  7. A combination of a dairy product fermented by lactobacilli and galactooligosaccharides shows additive effects on mineral balances in growing rats with hypochlorhydria induced by a proton pump inhibitor.

    Science.gov (United States)

    Takasugi, Satoshi; Ashida, Kinya; Maruyama, Suyaka; Matsukiyo, Yukari; Kaneko, Tetsuo; Yamaji, Taketo

    2013-06-01

    This study aimed to investigate the effects of a combination of a dairy product fermented by lactobacilli (DFL) and galactooligosaccharides (GOS) on mineral balances in growing rats with hypochlorhydria induced by a proton pump inhibitor (PPI). Three-week-old male rats were assigned to receive one of six diets: a control diet, control diets containing 1.6 or 5.0 % GOS, a DFL diet and DFL diets containing 1.6 or 5.0 % GOS for 9 days. From day 5 of the feeding period, half of the rats fed with control diets were subcutaneously administered with saline, whereas the remaining rats were administered with PPI for 5 days. Calcium (Ca), phosphorus (P), magnesium (Mg), iron (Fe) and zinc (Zn) balances were determined from days 6 to 9. PPI administration significantly decreased the apparent absorption of Ca and Fe and increased urinary P excretion, resulting in decreased Ca, Fe and P retention. GOS dose-dependently increased the apparent absorption of Ca, Mg and Fe and urinary Mg excretion and decreased urinary P excretion. DFL significantly increased the apparent absorption of Ca and Mg and urinary Mg excretion. The combination of DFL and GOS additively affected these parameters, resulting in increased Ca, P and Fe retention, and it further increased the apparent absorption and retention of Zn at 5.0 % GOS. In conclusion, the combination of DFL and GOS improves Ca, P and Fe retention in an additive manner and increases the Zn retention in growing rats with hypochlorhydria induced by PPI.

  8. A dairy product fermented by lactobacilli cancels the adverse effects of hypochlorhydria induced by a proton pump inhibitor on bone metabolism in growing rats.

    Science.gov (United States)

    Takasugi, Satoshi; Ashida, Kinya; Maruyama, Suyaka; Komaba, Yukari; Kaneko, Tetsuo; Yamaji, Taketo

    2011-11-01

    The purpose of the present study is to investigate the effects of hypochlorhydria induced by proton pump inhibitor (PPI) administration and intake of a dairy product fermented by lactobacilli (DFL) on bone metabolism in growing rats. Male rats, aged 3 weeks, were divided into two groups: a control group fed a casein-based diet and a group fed a DFL-based diet. Each group was fed its respective experimental diets for 9 d. At day 5 of the feeding period, each group was divided into two subgroups: one that received a saline injection and one that received a PPI injection. Rats were subcutaneously administered saline or PPI for 5 d. Faecal Ca excretion was determined from day 6 to day 9. At the end of the experiment, plasma and femurs were collected. Administration of PPI significantly decreased bone mineral density (shown by X-ray computerised tomography) and bone strength (shown by a three-point bending test) in the control group. Plasma osteocalcin, type I collagen C-telopeptides, 1,25-dihydroxyvitamin D and parathyroid hormone concentrations were elevated by PPI administration in the control group. Faecal Ca excretion and urinary P excretion in the control group were remarkably increased by PPI administration. On the other hand, these adverse effects of PPI were not observed in the DFL group. These results suggest that hypochlorhydria-induced bone loss may result from high bone turnover induced by secondary hyperparathyroidism due to Ca malabsorption and that DFL intake cancels these adverse effects probably via improving Ca malabsorption in growing rats.

  9. Comparison of the human gastric microbiota in hypochlorhydric states arising as a result of Helicobacter pylori-induced atrophic gastritis, autoimmune atrophic gastritis and proton pump inhibitor use.

    Directory of Open Access Journals (Sweden)

    Bryony N Parsons

    2017-11-01

    Full Text Available Several conditions associated with reduced gastric acid secretion confer an altered risk of developing a gastric malignancy. Helicobacter pylori-induced atrophic gastritis predisposes to gastric adenocarcinoma, autoimmune atrophic gastritis is a precursor of type I gastric neuroendocrine tumours, whereas proton pump inhibitor (PPI use does not affect stomach cancer risk. We hypothesised that each of these conditions was associated with specific alterations in the gastric microbiota and that this influenced subsequent tumour risk. 95 patients (in groups representing normal stomach, PPI treated, H. pylori gastritis, H. pylori-induced atrophic gastritis and autoimmune atrophic gastritis were selected from a cohort of 1400. RNA extracted from gastric corpus biopsies was analysed using 16S rRNA sequencing (MiSeq. Samples from normal stomachs and patients treated with PPIs demonstrated similarly high microbial diversity. Patients with autoimmune atrophic gastritis also exhibited relatively high microbial diversity, but with samples dominated by Streptococcus. H. pylori colonisation was associated with decreased microbial diversity and reduced complexity of co-occurrence networks. H. pylori-induced atrophic gastritis resulted in lower bacterial abundances and diversity, whereas autoimmune atrophic gastritis resulted in greater bacterial abundance and equally high diversity compared to normal stomachs. Pathway analysis suggested that glucose-6-phospahte1-dehydrogenase and D-lactate dehydrogenase were over represented in H. pylori-induced atrophic gastritis versus autoimmune atrophic gastritis, and that both these groups showed increases in fumarate reductase. Autoimmune and H. pylori-induced atrophic gastritis were associated with different gastric microbial profiles. PPI treated patients showed relatively few alterations in the gastric microbiota compared to healthy subjects.

  10. Comparison of the human gastric microbiota in hypochlorhydric states arising as a result of Helicobacter pylori-induced atrophic gastritis, autoimmune atrophic gastritis and proton pump inhibitor use

    Science.gov (United States)

    Eccles, Richard; Duckworth, Carrie A.; Varro, Andrea

    2017-01-01

    Several conditions associated with reduced gastric acid secretion confer an altered risk of developing a gastric malignancy. Helicobacter pylori-induced atrophic gastritis predisposes to gastric adenocarcinoma, autoimmune atrophic gastritis is a precursor of type I gastric neuroendocrine tumours, whereas proton pump inhibitor (PPI) use does not affect stomach cancer risk. We hypothesised that each of these conditions was associated with specific alterations in the gastric microbiota and that this influenced subsequent tumour risk. 95 patients (in groups representing normal stomach, PPI treated, H. pylori gastritis, H. pylori-induced atrophic gastritis and autoimmune atrophic gastritis) were selected from a cohort of 1400. RNA extracted from gastric corpus biopsies was analysed using 16S rRNA sequencing (MiSeq). Samples from normal stomachs and patients treated with PPIs demonstrated similarly high microbial diversity. Patients with autoimmune atrophic gastritis also exhibited relatively high microbial diversity, but with samples dominated by Streptococcus. H. pylori colonisation was associated with decreased microbial diversity and reduced complexity of co-occurrence networks. H. pylori-induced atrophic gastritis resulted in lower bacterial abundances and diversity, whereas autoimmune atrophic gastritis resulted in greater bacterial abundance and equally high diversity compared to normal stomachs. Pathway analysis suggested that glucose-6-phospahte1-dehydrogenase and D-lactate dehydrogenase were over represented in H. pylori-induced atrophic gastritis versus autoimmune atrophic gastritis, and that both these groups showed increases in fumarate reductase. Autoimmune and H. pylori-induced atrophic gastritis were associated with different gastric microbial profiles. PPI treated patients showed relatively few alterations in the gastric microbiota compared to healthy subjects. PMID:29095917

  11. Predicting the efficacy of proton pump inhibitors in patients with non-erosive reflux disease before therapy using dual-channel 24-h esophageal pH monitoring.

    Science.gov (United States)

    Shimatani, Tomohiko; Sugimoto, Mitsushige; Nishino, Masafumi; Adachi, Kyoichi; Furuta, Kenji; Ito, Masanori; Kurosawa, Susumu; Manabe, Noriaki; Mannen, Kotaro; Hongo, Michio; Chiba, Tsutomu; Kinoshita, Yoshikazu

    2012-05-01

    We aimed to determine whether reflux- and symptom-related parameters can predict the efficacy of proton pump inhibitors (PPI) in non-erosive reflux disease (NERD). Twenty-seven NERD patients who had experienced heartburn more than once a week within the previous month were enrolled. Intraesophageal pH before therapy was measured simultaneously at 5 and 15 cm above the esophagogastric junction (EGJ) for 24 h. The PPI rabeprazole was administered at a dose of 10 mg once daily for 4 weeks. In the event that heartburn was not relieved, the dose was increased to 10 mg twice daily for an additional 2 weeks, and again to 20 mg twice daily for another 2 weeks. Univariate analysis demonstrated no significant associations between any reflux- or symptom-related parameters at either site and complete heartburn relief after 4 weeks, or cumulative complete heartburn relief after 8 weeks. However, post-hoc analysis demonstrated more satisfactory heartburn relief after 4 weeks in patients with a high symptom index compared with those with a low symptom index, at 5 cm above the EGJ (P = 0.009). Cumulative satisfactory heartburn relief after 8 weeks was also greater in patients with a high total number of acid reflux episodes compared with those with a low total number of episodes, at 15 cm above the EGJ (P = 0.037). Pre-therapeutic pH monitoring in the lower and mid-esophagus is useful for predicting the efficacy of PPI in NERD patients. © 2011 Journal of Gastroenterology and Hepatology Foundation and Blackwell Publishing Asia Pty Ltd.

  12. Concomitant use of proton pump inhibitors and clopidogrel in patients with coronary, cerebrovascular, or peripheral artery disease in the factores de Riesgo y ENfermedad Arterial (FRENA) registry.

    Science.gov (United States)

    Muñoz-Torrero, Juan Francisco Sánchez; Escudero, Domingo; Suárez, Carmen; Sanclemente, Carmen; Pascual, Ma Teresa; Zamorano, José; Trujillo-Santos, Javier; Monreal, Manuel

    2011-01-01

    Among patients receiving clopidogrel for coronary artery disease, concomitant therapy with proton pump inhibitors (PPIs) has been associated with an increased risk for recurrent coronary events. Factores de Riesgo y ENfermedad Arterial (FRENA) is an ongoing, multicenter, observational registry of consecutive outpatients with coronary artery disease, cerebrovascular disease, or peripheral artery disease. We retrospectively examined the influence of concomitant use of PPIs on outcome in patients receiving clopidogrel. As of March 2009, 1222 patients were using clopidogrel: 595 had coronary artery disease, 329 cerebrovascular disease, and 298 had peripheral artery disease. Of these, 519 (42%) were concomitantly using PPIs. Over a mean follow-up of 15 months, 131 patients (11%) had 139 subsequent ischemic events: myocardial infarction 44, ischemic stroke 40, and critical limb ischemia 55. Seventeen of them (13%) died within 15 days of the subsequent event. PPI users had a higher incidence of myocardial infarction (rate ratio, 2.5; 95% confidence interval [CI], 1.3-4.8), ischemic stroke (rate ratio, 1.9; 95% CI, 1.03-3.7), and a nonsignificantly higher rate of critical limb ischemia (rate ratio, 1.6; 95% CI, 0.95-2.8) than nonusers. On multivariate analysis, concomitant use of clopidogrel and PPIs was independently associated with an increased risk for subsequent ischemic events both in the whole series of patients (hazard ratio, 1.8; 95% CI, 1.1-2.7) and in those with cerebrovascular disease or peripheral artery disease (hazard ratio, 1.5; 95% CI, 1.01-2.4). In patients with established arterial disease, concomitant use of PPIs and clopidogrel was associated with a nearly doubling of the incidence of subsequent myocardial infarction or ischemic stroke. This higher incidence persisted after multivariate adjustment.

  13. Proton pump inhibitors drastically modify triosephosphate isomerase from Giardia lamblia at functional and structural levels, providing molecular leads in the design of new antigiardiasic drugs.

    Science.gov (United States)

    García-Torres, Itzhel; de la Mora-de la Mora, Ignacio; Marcial-Quino, Jaime; Gómez-Manzo, Saúl; Vanoye-Carlo, América; Navarrete-Vázquez, Gabriel; Colín-Lozano, Blanca; Gutiérrez-Castrellón, Pedro; Sierra-Palacios, Edgar; López-Velázquez, Gabriel; Enríquez-Flores, Sergio

    2016-01-01

    Proton pump inhibitors (PPIs) are extensively used in clinical practice because of their effectiveness and safety. Omeprazole is one of the best-selling drugs worldwide and, with other PPIs, has been proposed to be potential drugs for the treatment of several diseases. We demonstrated that omeprazole shows cytotoxic effects in Giardia and concomitantly inactivates giardial triosephosphate isomerase (GlTIM). Therefore, we evaluated the efficiency of commercially available PPIs to inactivate this enzyme. We assayed the effect of PPIs on the GlTIM WT, single Cys mutants, and the human counterpart, following enzyme activity, thermal stability, exposure of hydrophobic regions, and susceptibility to limited proteolysis. PPIs efficiently inactivated GlTIM; however, rabeprazole was the best inactivating drug and was nearly ten times more effective. The mechanism of inactivation by PPIs was through the modification of the Cys 222 residue. Moreover, there are important changes at the structural level, the thermal stability of inactivated-GlTIM was drastically diminished and the structural rigidity was lost, as observed by the exposure of hydrophobic regions and their susceptibility to limited proteolysis. Our results demonstrate that rabeprazole is the most potent PPI for GlTIM inactivation and that all PPIs tested have substantial abilities to alter GITIM at the structural level, causing serious damage. This is the first report demonstrating the effectiveness of commercial PPIs on a glycolytic parasitic enzyme, with structural features well known. This study is a step forward in the use and understanding the implicated mechanisms of new antigiardiasic drugs safe in humans. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Triple therapy with high-dose proton-pump inhibitor, amoxicillin, and doxycycline is useless for Helicobacter pylori eradication: a proof-of-concept study.

    Science.gov (United States)

    Almeida, Nuno; Romãozinho, José M; Donato, Maria M; Luxo, Cristina; Cardoso, Olga; Cipriano, Maria A; Marinho, Carol; Sofia, Carlos

    2014-04-01

    Helicobacter pylori resistance to antibiotics is steadily increasing and multidrug-resistant strains are common and difficult to eliminate, mainly in countries where bismuth, tetracycline, furazolidone, and rifabutin are unavailable. To evaluate the efficacy and safety of a triple therapy with proton-pump inhibitor (PPI), amoxicillin, and doxycycline in patients with multidrug-resistant H. pylori. This prospective study involved 16 patients (13 females; mean age - 50 ± 11.3 years) infected by H. pylori with known resistance to clarithromycin, metronidazole, and levofloxacin, but susceptibility to amoxicillin and tetracycline. All patients were previously submitted to upper endoscopy with gastric biopsies for H. pylori culture and susceptibility testing by Etest. Mutations in 23S rRNA and gyrA genes were determined by real-time PCR. A 10-day eradication regimen with PPI (double-standard dose b.i.d.), amoxicillin (1000 mg b.i.d.), and doxycycline (100 mg b.i.d.) was prescribed after pretreatment with PPI during 3 days. Eradication success was assessed by (13) C-urea breath test 6-10 weeks after treatment. Compliance and adverse events were determined through phone contact immediately after treatment and specific written questionnaires. Only one patient did not complete treatment due to adverse events. Another four patients experienced mild side effects not affecting compliance. The control (13) C-urea breath test was positive in all patients. Per-protocol and intention-to-treat eradication rates were 0%. Although safe, a triple-therapy protocol with high-dose PPI, amoxicillin, and doxycycline is useless for multidrug-resistant H. pylori eradication. © 2014 John Wiley & Sons Ltd.

  15. No Association of Proton Pump Inhibitor Use with Fasting or Postload Glycaemia in Patients with Cardiovascular Disease: A Cross-Sectional Retrospective Study

    Science.gov (United States)

    Kruszelnicka, Olga; Kuźma, Marcin; Pena, Iwona Z.; Perera, Ian B.; Chyrchel, Bernadeta; Wieczorek-Surdacka, Ewa; Surdacki, Andrzej

    2017-01-01

    Background: Proton pump inhibitor (PPI) use was reportedly associated with an excess of adverse cardiovascular (CV) events, thus making their systemic effects relevant to public health. PPIs reduce gastric acid secretion, causing increased gastrin release. Gastrin stimulates β-cell neogenesis and enhances insulin release, exerting an incretin-like effect. Our aim was to assess, if PPI usage is associated with altered glycaemia in patients with CV disease. Methods: We retrospectively analyzed medical records of 102 subjects (80 with ischemic heart disease) who underwent a routine oral glucose tolerance test while hospitalized in a cardiology department. Fasting and 2-h postload glucose levels were compared according to PPI use for ≥1 month prior to admission. Results: Compared to 51 subjects without PPIs, those on a PPI were older, more frequently male, had a lower body-mass index and a tendency to a worse renal function. PPI users and non-users exhibited similar glucose levels at baseline (5.6 ± 0.9 vs. 5.5 ± 1.1 mmol/l, P = 0.5) and 2-hrs post glucose intake (9.8 ± 3.0 vs. 9.9 ± 3.4 mmol/l, P = 0.9). This was consistent across subgroups stratified by gender or diabetes status. The results were substantially unchanged after adjustment for different characteristics of subjects with and without PPIs. Conclusions: PPI use does not appear associated with altered glycaemia in subjects with CV disease. Unchanged glucose tolerance despite PPI usage may result from simultaneous activation of pathways that counteract the putative PPI-induced incretin-like effect. PMID:28924374

  16. Proton pump inhibitors decrease eotaxin-3/CCL26 expression in patients with chronic rhinosinusitis with nasal polyps: Possible role of the nongastric H,K-ATPase.

    Science.gov (United States)

    Min, Jin-Young; Ocampo, Christopher J; Stevens, Whitney W; Price, Caroline P E; Thompson, Christopher F; Homma, Tetsuya; Huang, Julia H; Norton, James E; Suh, Lydia A; Pothoven, Kathryn L; Conley, David B; Welch, Kevin C; Shintani-Smith, Stephanie; Peters, Anju T; Grammer, Leslie C; Harris, Kathleen E; Hulse, Kathryn E; Kato, Atsushi; Modyanov, Nikolai N; Kern, Robert C; Schleimer, Robert P; Tan, Bruce K

    2017-01-01

    Chronic rhinosinusitis with nasal polyps (CRSwNP) is often characterized by tissue eosinophilia that is associated with poor prognosis. Recent findings that proton pump inhibitors (PPIs) directly modulate the expression of eotaxin-3, an eosinophil chemoattractant, in patients with eosinophilic diseases suggest therapeutic potential for PPIs in those with CRSwNP. We assessed the effect of type 2 mediators, particularly IL-13 and eotaxin-3, on tissue eosinophilia and disease severity in patients with chronic rhinosinusitis (CRS). Further investigation focused on PPI suppression of eotaxin-3 expression in vivo and in vitro, with exploration of underlying mechanisms. Type 2 mediator levels in nasal tissues and secretions were measured by using a multiplex immunoassay. Eotaxin-3 and other chemokines expressed in IL-13-stimulated human sinonasal epithelial cells (HNECs) and BEAS-2B cells with or without PPIs were assessed by using ELISA, Western blotting, real-time PCR, and intracellular pH imaging. Nasal tissues and secretions from patients with CRSwNP had increased IL-13, eotaxin-2, and eotaxin-3 levels, and these were positively correlated with tissue eosinophil cationic protein levels and radiographic scores in patients with CRS (P H(+),K(+)-exchange, which was blocked by PPIs and the mechanistically unrelated H,K-ATPase inhibitor, SCH-28080. Furthermore, knockdown of ATP12A (gene for the nongastric H,K-ATPase) significantly attenuated IL-13-induced eotaxin-3 expression in HNECs. PPIs also had effects on accelerating IL-13-induced eotaxin-3 mRNA decay. Our results demonstrated that PPIs reduce IL-13-induced eotaxin-3 expression by airway epithelial cells. Furthermore, mechanistic studies suggest that the nongastric H,K-ATPase is necessary for IL-13-mediated epithelial responses, and its inhibitors, including PPIs, might be of therapeutic value in patients with CRSwNP by reducing epithelial production of eotaxin-3. Copyright © 2016 American Academy of Allergy

  17. Proton pump inhibitor use and fracture risk - effect modification by histamine H1 receptor blockade. Observational case-control study using National Prescription Data.

    Science.gov (United States)

    Abrahamsen, Bo; Vestergaard, Peter

    2013-11-01

    It remains unknown why proton pump inhibitor (PPI) use may be associated with risk of osteoporotic fractures; evidence of direct effects on calcium absorption or on the osteoclast in humans is weak or absent. However, the ensuing increased gastrin levels may cause histamine production through hypertrophy of gastric enterochromaffin like cells, which could lead to bone loss. We speculated that H1 receptor antagonists (H1RA) used for allergies would then reduce the effect of PPI on bone. We therefore conducted a register-based case-control study comprising 124,655 patients with hospital treated fractures, who were matched 3:1 with non fracture control subjects of the same age and gender. Use of prescription medications was retrieved from the National Prescription Database and data was analyzed using conditional logistic regression analysis. We observed a significant interaction between PPI and H1RA use on fracture risk in general (adjusted OR 0.92, 95% CI 0.87-0.98) though not on hip fracture risk (adjusted OR 0.99, 95% CI 0.85-1.16). There was a significant modification of the interaction by age (pfracture categories). As previously shown, fracture risk was higher in PPI users both for fractures in general and for hip fractures. Irrespective of PPI use, H1RA users had lower risk of hip fractures than non-users (adjusted OR 0.86, 95% CI 0.79-0.93). This short report suggests that the effects of PPI on bone could be driven by in part by increased histamine release as the increased fracture risk can be modified by H1RA. © 2013.

  18. [Survey of the prescriptions of proton pump inhibitors in patients admitted in an internal medicine ward: how is the compliance to the French guidelines?].

    Science.gov (United States)

    Sauvaget, L; Rolland, L; Dabadie, S; Desblaches, J; Bernard, N; Vandenhende, M-A; Bonnet, F; Pédeboscq, S; Morlat, P

    2015-10-01

    In June 2009, the national French authority for Health reported many off-label uses of proton pump inhibitors (PPI). Our objective was to analyse the justification and modalities of PPI prescriptions in patients before their admission in a department of internal medicine. Data were prospectively collected during 5months. At admission, all prescriptions of PPI by general practitioners (GP) were recorded. The accordance of the prescriptions with the marketing authorization indications and the French guidelines in terms of duration of treatment or dosage was analyzed. These informations were obtained from computerized medical records and, if necessary, by contacting GPs. We collected 173 prescriptions. Fifty-six (32%) were in accordance with marketing authorization indications and, among them, 15 prescriptions (9% of all) respected the French guidelines about dosage and duration of treatment. One hundred and six prescriptions (61%) were not adequate and among them an off-label use was notified in 91 (53% of all); among them 33% for simple dyspeptic disorders, 23% for the prevention of NSAID-induced lesions in patients without risk factors, and finally 17% for the prevention of stress ulcer. Fifty-two prescriptions (30%) were unclassified due to incomplete data. Our study showed that a vast majority of the prescriptions for PPIs are not in accordance with French guidelines. Preventive actions against abusive prescriptions, withdrawal strategies or replacement of already prescribed PPIs should be implemented to reduce the risk of side effects and the economic impact of long term use of PPIs. Copyright © 2015 Société nationale française de médecine interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  19. Immediate-type hypersensitivity reactions to proton pump inhibitors: usefulness of skin tests in the diagnosis and assessment of cross-reactivity.

    Science.gov (United States)

    Kepil Özdemir, S; Yılmaz, I; Aydin, Ö; Büyüköztürk, S; Gelincik, A; Demirtürk, M; Erdoğdu, D; Cömert, S; Erdoğan, T; Karakaya, G; Kalyoncu, A F; Oner Erkekol, F; Dursun, A B; Misirligil, Z; Bavbek, S

    2013-08-01

    Data are limited about the value of skin tests in the diagnosis of proton pump inhibitor (PPI)-induced hypersensitivity reactions and the cross-reactivity between PPIs. We aimed to assess the role of skin testing in the diagnosis of PPI-related immediate hypersensitivity reactions and the cross-reactivity patterns among PPIs. The study was designed in a prospective, national, multicentre nature. Sixty-five patients with a suggestive history of a PPI-induced immediate hypersensitivity reaction and 30 control subjects were included. Standardized skin prick and intradermal tests were carried out with a panel of PPIs. Single-blind, placebo-controlled oral provocation tests (OPTs) with the PPIs other than the culprit PPI that displayed negative results in skin tests (n = 61) and diagnostic OPTs with the suspected PPI (n = 12) were performed. The suspected PPIs were lansoprazole (n = 52), esomeprazole (n = 11), pantoprazole (n = 9), rabeprazole (n = 2), and omeprazole (n = 1). The sensitivity, specificity, and negative and positive predictive values of the skin tests with PPIs were 58.8%, 100%, 70.8%, and 100%, respectively. Fifteen of the 31 patients with a hypersensitivity reaction to lansoprazole had a positive OPT or skin test result with at least one of the alternative PPIs (8/52 pantoprazole, 6/52 omeprazole, 5/52 esomeprazole, 3/52 rabeprazole). Considering the high specificity, skin testing seems to be a useful method for the diagnosis of immediate-type hypersensitivity reactions to PPIs and for the evaluation of cross-reactivity among PPIs. However, OPT should be performed in case of negativity on skin tests. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  20. Conflicting results between randomized trials and observational studies on the impact of proton pump inhibitors on cardiovascular events when coadministered with dual antiplatelet therapy: systematic review.

    Science.gov (United States)

    Melloni, Chiara; Washam, Jeffrey B; Jones, W Schuyler; Halim, Sharif A; Hasselblad, Victor; Mayer, Stephanie B; Heidenfelder, Brooke L; Dolor, Rowena J

    2015-01-01

    Discordant results have been reported on the effects of concomitant use of proton pump inhibitors (PPIs) and dual antiplatelet therapy (DAPT) for cardiovascular outcomes. We conducted a systematic review comparing the effectiveness and safety of concomitant use of PPIs and DAPT in the postdischarge treatment of unstable angina/non-ST-segment-elevation myocardial infarction patients. We searched for clinical studies in MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews, from 1995 to 2012. Reviewers screened and extracted data, assessed applicability and quality, and graded the strength of evidence. We performed meta-analyses of direct comparisons when outcomes and follow-up periods were comparable. Thirty-five studies were eligible. Five (4 randomized controlled trials and 1 observational) assessed the effect of omeprazole when added to DAPT; the other 30 (observational) assessed the effect of PPIs as a class when compared with no PPIs. Random-effects meta-analyses of the studies assessing PPIs as a class consistently reported higher event rates in patients receiving PPIs for various clinical outcomes at 1 year (composite ischemic end points, all-cause mortality, nonfatal MI, stroke, revascularization, and stent thrombosis). However, the results from randomized controlled trials evaluating omeprazole compared with placebo showed no difference in ischemic outcomes, despite a reduction in upper gastrointestinal bleeding with omeprazole. Large, well-conducted observational studies of PPIs and randomized controlled trials of omeprazole seem to provide conflicting results for the effect of PPIs on cardiovascular outcomes when coadministered with DAPT. Prospective trials that directly compare pharmacodynamic parameters and clinical events among specific PPI agents in patients with unstable angina/non-ST-segment-elevation myocardial infarction treated with DAPT are warranted. © 2015 American Heart Association, Inc.

  1. Use of proton pump inhibitors (PPI) and history of earlier fracture are independent risk factors for fracture in postmenopausal women. The WHILA study.

    Science.gov (United States)

    Moberg, Louise M E; Nilsson, Peter M; Samsioe, Göran; Borgfeldt, Christer

    2014-08-01

    Postmenopausal women in the Western world are highly burdened by osteoporotic fractures. The aim of this study is to investigate risk factors at baseline for fracture in 6416 postmenopausal women during long-term follow-up. At baseline, all women completed a questionnaire regarding background factors, diseases, current use of medications and reproductive and contraceptive history, a physical examination and laboratory analyses. Fracture occurrence after inclusion in the study was recorded with the help of official registries. All significant variables in univariate logistic regression with a decreased or increased risk for fracture were analysed in a multivariate logistic regression. Increased fracture risk was observed in women currently using proton pump inhibitors (PPI), odds ratio (OR) 2.53 (95% confidence interval (CI)) 1.28-4.99, and women having had a fracture after the age of 40, but before inclusion in the study, OR 1.70 (95% CI 1.24-2.32). A protective effect against fractures was observed in women with a positive family history of diabetes OR 0.66 (95% CI 0.44-0.98). A significant interaction was observed between fracture risk, use of PPI and HT status (p=0.014) and women with HT had an increased fracture risk with use of PPI (OR 3.37 (95% CI 1.96-5.80)) compared to women without HT (OR 1.13 (95% CI 0.57-2.24)). In conclusion, usage of PPIs was associated with a doubled risk for fracture in postmenopausal women. Women with previous fractures using PPI should be considered for prophylactic treatment reducing fracture risk. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Randomised clinical trial: addition of alginate-antacid (Gaviscon Double Action) to proton pump inhibitor therapy in patients with breakthrough symptoms.

    Science.gov (United States)

    Coyle, C; Crawford, G; Wilkinson, J; Thomas, S J; Bytzer, P

    2017-06-01

    Symptomatic breakthrough in proton pump inhibitor (PPI)-treated gastro-oesophageal reflux disease (GERD) patients is a common problem with a range of underlying causes. The nonsystemic, raft-forming action of alginates may help resolve symptoms. To assess alginate-antacid (Gaviscon Double Action, RB, Slough, UK) as add-on therapy to once-daily PPI for suppression of breakthrough reflux symptoms. In two randomised, double-blind studies (exploratory, n=52; confirmatory, n=262), patients taking standard-dose PPI who had breakthrough symptoms, assessed by Heartburn Reflux Dyspepsia Questionnaire (HRDQ), were randomised to add-on Gaviscon or placebo (20 mL after meals and bedtime). The exploratory study endpoint was change in HRDQ score during treatment vs run-in. The confirmatory study endpoint was "response" defined as ≥3 days reduction in the number of "bad" days (HRDQ [heartburn/regurgitation] >0.70) during treatment vs run-in. In the exploratory study, significantly greater reductions in HRDQ scores (heartburn/regurgitation) were observed in the Gaviscon vs placebo (least squares mean difference [95% CI] -2.10 [-3.71 to -0.48]; P=.012). Post hoc "responder" analysis of the exploratory study also revealed significantly more Gaviscon patients (75%) achieved ≥3 days reduction in "bad" days vs placebo patients (36%), P=.005. In the confirmatory study, symptomatic improvement was observed with add-on Gaviscon (51%) but there was no significant difference in response vs placebo (48%) (OR (95% CI) 1.15 (0.69-1.91), P=.5939). Adding Gaviscon to PPI reduced breakthrough GERD symptoms but a nearly equal response was observed for placebo. Response to intervention may vary according to whether symptoms are functional in origin. © 2017 John Wiley & Sons Ltd.

  3. Low Soluble Fms-Like Tyrosine Kinase-1, Endoglin, and Endothelin-1 Levels in Women With Confirmed or Suspected Preeclampsia Using Proton Pump Inhibitors.

    Science.gov (United States)

    Saleh, Langeza; Samantar, Raaho; Garrelds, Ingrid M; van den Meiracker, Anton H; Visser, Willy; Danser, A H Jan

    2017-09-01

    Patients with preeclampsia display elevated placenta-derived sFlt-1 (soluble Fms-like tyrosine kinase-1) and endoglin levels and decreased placental growth factor levels. Proton pump inhibitors (PPIs) decrease trophoblast sFlt-1 and endoglin secretion in vitro. PPIs are used during pregnancy to combat reflux disease. Here, we investigated whether PPIs affect sFlt-1 in women with confirmed/suspected preeclampsia, making use of a prospective cohort study involving 430 women. Of these women, 40 took PPIs (6 esomeprazole, 32 omeprazole, and 2 pantoprazole) for 8 to 45 (median 29) days before sFlt-1 measurement. Measurements were only made once, at study entry between weeks 20 and 41 (median 33 weeks). PPI use was associated with lower sFlt-1 levels, with no change in placental growth factor levels, both when compared with all non-PPI users and with 80 gestational age-matched controls selected from the non-PPI users. No sFlt-1/placental growth factor alterations were observed in women using ferrous fumarate or macrogol while, as expected, women using antihypertensive medication displayed higher sFlt-1 levels and lower placental growth factor levels. The PPI use-associated decrease in sFlt-1 was independent of the application of antihypertensive drugs and also occurred when restricting our analysis to patients with hypertensive disease of pregnancy at study entry. PPI users displayed more cases with preexisting proteinuria, less gestational hypertension, and a lower number of neonatal sepsis cases. Finally, their plasma endoglin and endothelin-1 levels were lower while sFlt-1 levels correlated positively with both. In conclusion, PPI use associates with low sFlt-1, endoglin, and endothelin-1 levels, warranting prospective trials to investigate the therapeutic potential of PPIs in preeclampsia. © 2017 American Heart Association, Inc.

  4. ATP4a is required for development and function of the Xenopus mucociliary epidermis - a potential model to study proton pump inhibitor-associated pneumonia.

    Science.gov (United States)

    Walentek, Peter; Beyer, Tina; Hagenlocher, Cathrin; Müller, Christina; Feistel, Kerstin; Schweickert, Axel; Harland, Richard M; Blum, Martin

    2015-12-15

    Proton pump inhibitors (PPIs), which target gastric H(+)/K(+)ATPase (ATP4), are among the most commonly prescribed drugs. PPIs are used to treat ulcers and as a preventative measure against gastroesophageal reflux disease in hospitalized patients. PPI treatment correlates with an increased risk for airway infections, i.e. community- and hospital-acquired pneumonia. The cause for this correlation, however, remains elusive. The Xenopus embryonic epidermis is increasingly being used as a model to study airway-like mucociliary epithelia. Here we use this model to address how ATP4 inhibition may affect epithelial function in human airways. We demonstrate that atp4a knockdown interfered with the generation of cilia-driven extracellular fluid flow. ATP4a and canonical Wnt signaling were required in the epidermis for expression of foxj1, a transcriptional regulator of motile ciliogenesis. The ATP4/Wnt module activated foxj1 downstream of ciliated cell fate specification. In multiciliated cells (MCCs) of the epidermis, ATP4a was also necessary for normal myb expression, apical actin formation, basal body docking and alignment of basal bodies. Furthermore, ATP4-dependent Wnt/β-catenin signaling in the epidermis was a prerequisite for foxa1-mediated specification of small secretory cells (SSCs). SSCs release serotonin and other substances into the medium, and thereby regulate ciliary beating in MCCs and protect the epithelium against infection. Pharmacological inhibition of ATP4 in the mature mucociliary epithelium also caused a loss of MCCs and led to impaired mucociliary clearance. These data strongly suggest that PPI-associated pneumonia in human patients might, at least in part, be linked to dysfunction of mucociliary epithelia of the airways. Copyright © 2015 Elsevier Inc. All rights reserved.

  5. The Influence of Proton Pump Inhibitors on the Fecal Microbiome of Infants with Gastroesophageal Reflux—A Prospective Longitudinal Interventional Study

    Directory of Open Access Journals (Sweden)

    Christoph Castellani

    2017-10-01

    Full Text Available Proton pump inhibitors (PPIs are the standard therapy for gastroesophageal reflux disease. In adults, PPI treatment is associated with Clostridium difficile infections (CDI. In contrast to adults the microbiome of infants develops from sterility at birth toward an adult-like profile in the first years of life. The effect of PPIs on this developing microbiome has never been studied. The aim of the present study was to determine the effect of oral PPIs on the fecal microbiome in infants with gastroesophageal reflux disease (GERD. In this prospective longitudinal study 12 infants with proven GERD received oral PPIs for a mean period of 18 weeks (range 8–44. Stool samples were collected before (“before PPI” and 4 weeks after initiation of PPI therapy (“on PPI”. A third sample was obtained 4 weeks after PPI discontinuation (“after PPI”. The fecal microbiome was determined by NGS based 16S rDNA sequencing. This trial was registered with clinicaltrials.gov (NCT02359604. In a comparison of “before PPI” and “on PPI” neither α- nor β-diversity changed significantly. On the genus level, however, the relative abundances showed a decrease of Lactobacillus and Stenotrophomonas and an increase of Haemophilus. After PPI therapy there was a significant increase of α- and β-diversity. Additionally, the relative abundances of the phyla Firmicutes, Bacteroidetes, and Proteobacteria were significantly changed and correlated to patients' age and the introduction of solid foods. PPI treatment has only minor effects on the fecal microbiome. After discontinuation of PPI treatment the fecal microbiome correlated to patients' age and nutrition.

  6. Proton pump inhibitor monotherapy and the risk of cardiovascular events in patients with gastro-esophageal reflux disease: a meta-analysis.

    Science.gov (United States)

    Sun, S; Cui, Z; Zhou, M; Li, R; Li, H; Zhang, S; Ba, Y; Cheng, G

    2017-02-01

    Proton pump inhibitors (PPIs) are commonly used as potent gastric acid secretion antagonists for gastro-esophageal disorders and their overall safety in patients with gastro-esophageal reflux disease (GERD) is considered to be good and they are well-tolerated. However, recent studies have suggested that PPIs may be a potential independent risk factor for cardiovascular adverse events. The aim of our meta-analysis was to examine the association between PPI monotherapy and cardiovascular events in patients with GERD. A literature search involved examination of relevant databases up to July 2015 including PubMed, Cochrane Library, EMBASE, and ClinicalTrial.gov, as well as selected randomized controlled trials (RCTs) reporting cardiovascular events with PPI exposure in GERD patients. In addition, the pooled risk ratio (RR) and heterogeneity were assessed based on a fixed effects model of the meta-analysis and the I2 statistic, respectively. Seventeen RCTs covering 7540 patients were selected. The pooled data suggested that the use of PPIs was associated with a 70% increased cardiovascular risk (RR=1.70, 95% CI: [1.13-2.56], P=.01, I2 =0%). Furthermore, higher risks of adverse cardiovascular events in the omeprazole subgroup (RR=3.17, 95% CI: [1.43-7.03], P=.004, I2 =25%) and long-term treatment subgroup (RR=2.33, 95% CI: [1.33-4.08], P=.003, I2 =0%) were found. PPI monotherapy can be a risk factor for cardiovascular adverse events. Omeprazole could significantly increase the risk of cardiovascular events and, so, should be used carefully. © 2016 John Wiley & Sons Ltd.

  7. Expression of the H+-ATPase AHA10 proton pump is associated with citric acid accumulation in lemon juice sac cells.

    Science.gov (United States)

    Aprile, Alessio; Federici, Claire; Close, Timothy J; De Bellis, Luigi; Cattivelli, Luigi; Roose, Mikeal L

    2011-12-01

    The sour taste of lemons (Citrus limon (L.) Burm.) is determined by the amount of citric acid in vacuoles of juice sac cells. Faris is a "sweet" lemon variety since it accumulates low levels of citric acid. The University of California Riverside Citrus Variety Collection includes a Faris tree that produces sweet (Faris non-acid; FNA) and sour fruit (Faris acid; FA) on different branches; it is apparently a graft chimera with layer L1 derived from Millsweet limetta and layer L2 from a standard lemon. The transcription profiles of Faris sweet lemon were compared with Faris acid lemon and Frost Lisbon (L), which is a standard sour lemon genetically indistinguishable from Faris in prior work with SSR markers. Analysis of microarray data revealed that the transcriptomes of the two sour lemon genotypes were nearly identical. In contrast, the transcriptome of Faris sweet lemon was very different from those of both sour lemons. Among about 1,000 FNA-specific, presumably pH-related genes, the homolog of Arabidopsis H(+)-ATPase proton pump AHA10 was not expressed in FNA, but highly expressed in FA and L. Since Arabidopsis AHA10 is involved in biosynthesis and acidification of vacuoles, the lack of expression of the AHA10 citrus homolog represents a very conspicuous molecular feature of the FNA sweet phenotype. In addition, high expression of several 2-oxoglutarate degradation-related genes in FNA suggests activation of the GABA shunt and degradation of valine and tyrosine as components of the mechanism that reduces the level of citric acid in sweet lemon.

  8. Effects of membrane curvature and pH on proton pumping activity of single cytochrome bo3 enzymes

    DEFF Research Database (Denmark)

    Li, Mengqiu; Khan, Sanobar; Rong, Honglin

    2017-01-01

    that the pH optimum is related to proton release from the proton exit site. Our previous single-enzyme experiments identified rare, long-lived conformation states of cytochrome bo3 where protons leak back under turn-over conditions. Here, we analyzed and found that ~ 23% of cytochrome bo3 proteoliposomes...

  9. A light-driven sodium ion pump in marine bacteria.

    Science.gov (United States)

    Inoue, Keiichi; Ono, Hikaru; Abe-Yoshizumi, Rei; Yoshizawa, Susumu; Ito, Hiroyasu; Kogure, Kazuhiro; Kandori, Hideki

    2013-01-01

    Light-driven proton-pumping rhodopsins are widely distributed in many microorganisms. They convert sunlight energy into proton gradients that serve as energy source of the cell. Here we report a new functional class of a microbial rhodopsin, a light-driven sodium ion pump. We discover that the marine flavobacterium Krokinobacter eikastus possesses two rhodopsins, the first, KR1, being a prototypical proton pump, while the second, KR2, pumps sodium ions outward. Rhodopsin KR2 can also pump lithium ions, but converts to a proton pump when presented with potassium chloride or salts of larger cations. These data indicate that KR2 is a compatible sodium ion-proton pump, and spectroscopic analysis showed it binds sodium ions in its extracellular domain. These findings suggest that light-driven sodium pumps may be as important in situ as their proton-pumping counterparts.

  10. Evaluación del uso de los inhibidores de la bomba de protones en un servicio de medicina interna Assessing the use of proton pump inhibitors in an internal medicine department

    Directory of Open Access Journals (Sweden)

    E. Martín-Echevarría

    2008-02-01

    Full Text Available Introducción: los inhibidores de la bomba de protones (IBP bloquean la enzima H+/K+ ATPasa en las células parietales gástricas, logrando la inhibición de la secreción de ácido clorhídrico de forma basal como tras estimulación. Las indicaciones apropiadas para su uso son: enfermedad por reflujo gastroesofágico, hemorragia digestiva aguda, úlceras activas, gastritis o esofagitis erosiva, dispepsia, gastropatía por AINE, profilaxis de úlcera de estrés en pacientes de riesgo. El objetivo del estudio fue la revisión de las indicaciones de los IBP en nuestro medio y la evaluación de su utilización en el Hospital Universitario de Guadalajara. Material y métodos: se realizó un estudio de corte transversal analítico con selección aleatoria de los pacientes atendidos en el Servicio de Medicina Interna durante todo el año 2003. Se revisaron un total de 208 historias de 832 pacientes (un 25% a los que se administraron IBP. La edad media fue de 67 años (rango 16-92, el 46,2% fueron mujeres y las enfermedades subyacentes más frecuentes fueron: HTA, EPOC y DM. Resultados: un 34,6% de los pacientes tomaban IBP antes del ingreso. De estos, el 68,1% no tenía indicación. Durante el ingreso se prescribió de forma inadecuada el IBP al 73,07% y al alta, se mantenía el IBP sin indicación correcta. Conclusiones: los resultados están en concordancia con los anteriormente publicados, manteniéndose una alta frecuencia de uso incorrecto de los IBP y siendo recomendable una utilización más racional para evitar los efectos secundarios, las interacciones con otros fármacos y aportar una atención médica más eficiente.Introduction: proton pump inhibitors (PPIs block the H+/K+ ATPase enzyme in gastric wall cells, leading to an inhibition of both baseline and stimulated acid secretion. Appropriate indications include: Gastroesophageal reflux, acute upper gastrointestinal bleeding, erosive gastritis or esophagitis, dyspepsia, NSAID

  11. The proton pump inhibitor, omeprazole, but not lansoprazole or pantoprazole, is a metabolism-dependent inhibitor of CYP2C19: implications for coadministration with clopidogrel.

    Science.gov (United States)

    Ogilvie, Brian W; Yerino, Phyllis; Kazmi, Faraz; Buckley, David B; Rostami-Hodjegan, Amin; Paris, Brandy L; Toren, Paul; Parkinson, Andrew

    2011-11-01

    As a direct-acting inhibitor of CYP2C19 in vitro, lansoprazole is more potent than omeprazole and other proton pump inhibitors (PPIs), but lansoprazole does not cause clinically significant inhibition of CYP2C19 whereas omeprazole does. To investigate this apparent paradox, we evaluated omeprazole, esomeprazole, R-omeprazole, lansoprazole, and pantoprazole for their ability to function as direct-acting and metabolism-dependent inhibitors (MDIs) of CYP2C19 in pooled human liver microsomes (HLM) as well as in cryopreserved hepatocytes and recombinant CYP2C19. In HLM, all PPIs were found to be direct-acting inhibitors of CYP2C19 with IC(50) values varying from 1.2 μM [lansoprazole; maximum plasma concentration (C(max)) = 2.2 μM] to 93 μM (pantoprazole; C(max) = 6.5 μM). In addition, we identified omeprazole, esomeprazole, R-omeprazole, and omeprazole sulfone as MDIs of CYP2C19 (they caused IC(50) shifts after a 30-min preincubation with NADPH-fortified HLM of 4.2-, 10-, 2.5-, and 3.2-fold, respectively), whereas lansoprazole and pantoprazole were not MDIs (IC(50) shifts omeprazole and esomeprazole was not reversed by ultracentrifugation, suggesting that the inhibition was irreversible (or quasi-irreversible), whereas ultracentrifugation largely reversed such effects of R-omeprazole. Under various conditions, omeprazole inactivated CYP2C19 with K(I) (inhibitor concentration that supports half the maximal rate of inactivation) values of 1.7 to 9.1 μM and k(inact) (maximal rate of enzyme inactivation) values of 0.041 to 0.046 min(-1). This study identified omeprazole, and esomeprazole, but not R-omeprazole, lansoprazole, or pantoprazole, as irreversible (or quasi-irreversible) MDIs of CYP2C19. These results have important implications for the mechanism of the clinical interaction reported between omeprazole and clopidogrel, as well as other CYP2C19 substrates.

  12. Comparison of inhibitory effects of the proton pump-inhibiting drugs omeprazole, esomeprazole, lansoprazole, pantoprazole, and rabeprazole on human cytochrome P450 activities.

    Science.gov (United States)

    Li, Xue-Qing; Andersson, Tommy B; Ahlström, Marie; Weidolf, Lars

    2004-08-01

    The human clearance of proton pump inhibitors (PPIs) of the substituted benzimidazole class is conducted primarily by the hepatic cytochrome P450 (P450) system. To compare the potency and specificity of the currently used PPIs (i.e., omeprazole, esomeprazole, lansoprazole, pantoprazole, and rabeprazole) as inhibitors of four cytochrome P450 enzymes (CYP2C9, 2C19, 2D6, and 3A4), we performed in vitro studies using human liver microsomal preparations and recombinant CYP2C19. Sample analysis was done using selected reaction monitoring liquid chromatography/tandem mass spectometry. With several systems for CYP2C19 activity (two marker reactions, S-mephenytoin 4'-hydroxylation and R-omeprazole 5-hydroxylation, tested in either human liver microsomes or recombinant CYP2C19), the five PPIs showed competitive inhibition of CYP2C19 activity with K(i) of 0.4 to 1.5 microM for lansoprazole, 2 to 6 microM for omeprazole, approximately 8 microM for esomeprazole, 14 to 69 microM for pantoprazole, and 17 to 21 microM for rabeprazole. Pantoprazole was a competitive inhibitor of both CYP2C9-catalyzed diclofenac 4'-hydroxylation and CYP3A4-catalyzed midazolam 1'-hydroxylation (K(i) of 6 and 22 microM, respectively), which were at least 2 times more potent than the other PPIs. All PPIs were poor inhibitors of CYP2D6-mediated bufuralol 1'-hydroxylation with IC(50) > 200 microM. The inhibitory potency of a nonenzymatically formed product of rabeprazole, rabeprazole thioether, was also investigated and showed potent, competitive inhibition with K(i) values of 6 microM for CYP2C9, 2 to 8 microM for CYP2C19, 12 microM for CYP2D6, and 15 microM for CYP3A4. The inhibitory potency of R-omeprazole on the four studied P450 enzymes was also studied and showed higher inhibitory potency than its S-isomer on CYP2C9 and 2C19 activities. Our data suggest that, although the inhibitory profiles of the five studied PPIs were similar, lansoprazole and pantoprazole are the most potent in vitro inhibitors

  13. Brand Name and Generic Proton Pump Inhibitor Prescriptions in the United States: Insights from the National Ambulatory Medical Care Survey (2006–2010

    Directory of Open Access Journals (Sweden)

    Andrew J. Gawron

    2015-01-01

    Full Text Available Introduction. Proton pump inhibitors (PPI are one of the most commonly prescribed medication classes with similar efficacy between brand name and generic PPI formulations. Aims. We determined demographic, clinical, and practice characteristics associated with brand name PPI prescriptions at ambulatory care visits in the United States. Methods. Observational cross sectional analysis using the National Ambulatory Medical Care Survey (NAMCS of all adult (≥18 yrs of age ambulatory care visits from 2006 to 2010. PPI prescriptions were identified by using the drug entry code as brand name only or generic available formulations. Descriptive statistics were reported in terms of unweighted patient visits and proportions of encounters with brand name PPI prescriptions. Global chi-square tests were used to compare visits with brand name PPI prescriptions versus generic PPI prescriptions for each measure. Poisson regression was used to determine the incidence rate ratio (IRR for generic versus brand PPI prescribing. Results. A PPI was prescribed at 269.7 million adult ambulatory visits, based on 9,677 unweighted visits, of which 53% were brand name only prescriptions. In 2006, 76.0% of all PPI prescriptions had a brand name only formulation compared to 31.6% of PPI prescriptions in 2010. Visits by patients aged 25–44 years had the greatest proportion of brand name PPI formulations (57.9%. Academic medical centers and physician-owned practices had the greatest proportion of visits with brand name PPI prescriptions (58.9% and 55.6% of visits with a PPI prescription, resp.. There were no significant differences in terms of median income, patient insurance type, or metropolitan status when comparing the proportion of visits with brand name versus generic PPI prescriptions. Poisson regression results showed that practice ownership type was most strongly associated with the likelihood of receiving a brand name PPI over the entire study period. Compared to

  14. Rifabutin-based high-dose proton-pump inhibitor and amoxicillin triple regimen as the rescue treatment for Helicobacter pylori.

    Science.gov (United States)

    Lim, Hyun Chul; Lee, Yong Jae; An, Byoungrak; Lee, Seung Woo; Lee, Yong Chan; Moon, Byung Soo

    2014-12-01

    Rifabutin has been known to be effective in multidrug-resistant Helicobacter pylori-harboring patients undergoing treatment failure for H. pylori infection. To evaluate the efficacy of 7-day treatment regimen consisting rifabutin daily but increasing the dose of amoxicillin and lansoprazole in patients who have failed first and second eradication and to assess the side effect profiles in South Korea. From December 2007 to May 2013, 59 H. pylori-infected patients with two previous eradication failures were enrolled for this study prospectively. The eligible patients were randomly assigned to either group A or B. Group A received lansoprazole 30 mg bid, amoxicillin 1.0 g tid and rifabutin 150 mg bid during 7 days, whereas group B received lansoprazole 60 mg bid, amoxicillin 1.0 g tid and rifabutin 150 mg bid during 7 days. In group A, H. pylori eradication was achieved in 25 (78.1%) of the 32 patients in the ITT analysis and in 25 (80.6%) of the 31 patients in the PP analysis. In group B, H. pylori eradication was achieved in 26 (96.3%) of the 27 patients in the ITT analysis and in 27 (100%) of the 26 patients in the PP analysis. There was statistically significant difference between the two groups in terms of the eradication rates in PP analysis (p = .047), whereas a marginally statistical significance was found in terms of the eradication rates in ITT analysis (p = .051). Reported side effects were mild, and treatment was well tolerated. No major changes in physical examination or in standard laboratory parameters were observed after treatment. Rifabutin-based high-dose proton-pump inhibitor (PPI)-combined therapy as empirical rescue treatment is more effective than standard dose PPI-combined rifabutin-based therapy, safe and best tolerable in third-line therapy in the Korean population. The key to successful rescue therapy with rifabutin-amoxicillin-PPI regimen may be to increase doses of PPI. © 2014 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

  15. Comparative effectiveness and acceptability of the FDA-licensed proton pump inhibitors for erosive esophagitis: A PRISMA-compliant network meta-analysis.

    Science.gov (United States)

    Li, Mei-Juan; Li, Qing; Sun, Min; Liu, Li-Qin

    2017-09-01

    This study compared the effectiveness and acceptability of all Food and Drug Administration (FDA)-recommended dose proton pump inhibitors (PPIs) in erosive esophagitis (EE): Dexlansoprazole 60 mg, Esomeprazole 40 mg, Esomeprazole 20 mg, Pantoprazole 40 mg, Lansoprazole 30 mg, Rabeprazole 20 mg, Omeprazole 20 mg. A systematic literature search was performed using PubMed, Embase, and Cochrane Library. Totally, 25 randomized controlled trials (RCTs) met study selection criteria and were incorporated in this network meta-analysis (NMA) study. For the NMA, eligible RCTs of adults with EE verified by endoscopic examination were randomly assigned to the licensed PPIs at least 4 weeks of continuous therapy. The primary efficacy outcome was the endoscopic healing rates at 4 and 8 weeks. Heartburn relief rates were a secondary efficacy outcome. The rates of withdrawal were analyzed as a safety outcome. In comparison to the common comparator omeprazole 20 mg, esomeprazole 40 mg provided significantly healing rates at 4 weeks [odds ratio (OR), 1.46 (95% confidence interval, 95% CI, 1.24-1.71)] and 8 weeks [1.58 (1.29-1.92)], and improved the heartburn relief rates [1.29 (1.07-1.56)]. In comparison to lansoprazole 30 mg, esomeprazole 40 mg provided significantly healing rates at 4 weeks [1.30 (1.10-1.53)] and 8 weeks [1.37 (1.13-1.67)], and improved the heartburn relief rates [1.29 (1.03-1.62)]. In terms of acceptability, only dexlansoprazole 60 mg had significantly more all-cause discontinuation than omeprazole 20 mg [1.54 (1.03-2.29)], pantoprazole 40 mg [1.68 (1.08-2.63)], and lansoprazole 30 mg [1.38 (1.02-1.88)]. The standard-dose esomeprazole 40 mg had more superiority in mucosal erosion healing and heartburn relief. Esomeprazole 40 mg, pantoprazole 40 mg, esomeprazole 20 mg, and lansoprazole 30 mg showed more benefits in effectiveness and acceptability than other interventions.

  16. The effect of H. pylori infection, aging and consumption of proton pump inhibitors (PPIs on fungal colonization in the stomach of dyspeptic patients

    Directory of Open Access Journals (Sweden)

    Sadegh eMassarrat

    2016-05-01

    Full Text Available Background: The importance of coinfection of Helicobacter pylori (H. pylori and Candida albicans (C. albicans in the development of gastric diseases is not known. In this study, the frequency of concurrent infection of H. pylori and C. albicans in dyspeptic patients was assessed while considering age, gender and PPI consumption of patients. Methods: Gastric biopsies were taken from 74 yeast-positive dyspeptic patients and gastric disease, age, gender and proton pump inhibitor (PPI consumption of subjects were recorded. One antral biopsy was used for rapid urease test (RUT and one for H. pylori and yeast cultivation and smear preparation. Bacterial isolates were identified according to spiral morphology and the biochemical characteristics. Yeast isolates were identified on Chromagar and by the Nested-PCR amplification of C. albicans-specific topoisomerase II gene. Twenty seven biopsy smears were Gram-stained and examined by the light microscope for observing H. pylori and yeast cells.Results: Fifty four (73% of patients were >40 yr. Of 68 patients with PPI consumption record, 46 (67.6% consumed PPI (p=0. Comparison of patients in peptic ulcer group (12, 16.2% with (6, 8.1% or without (6, 8.1% H. pylori or in gastritis group (62, 83.8% with (25, 33.8% or without (37, 50% H. pylori showed no significant difference (p>0.05. Of the 46 patients who consumed PPI, 13 (17.5% were H. pylori-positive and 33 (44.6% H. pylori-negative (p=0. Ten out of 27 smears showed the occurrence of H. pylori cells, including three with yeast cells. Of the 17 H. pylori-negative smears, three showed the occurrence of yeast cells only. Yeasts stained Gram- positive or Gram- negative and appeared as single or budding cells.Conclusion: The older age and PPI consumption could favor fungal colonization in the human stomach. The occurrence of a considerable number of H. pylori-positive or H. pylori-negative patients with gastritis or peptic ulcer shows that co-infection of

  17. Gastroesophageal reflux disease-related symptom recurrence in patients discontinuing proton pump inhibitors for Bravo wireless esophageal pH monitoring study

    Directory of Open Access Journals (Sweden)

    R. Schey

    2017-10-01

    Full Text Available Background: Patients with gastroesophageal reflux disease (GERD are treated with proton pump inhibitors (PPIs. Those that do not achieve symptom relief, or non-responders, usually undergo esophageal pH monitoring off PPIs in order to confirm the presence of GERD. Aims: To assess the efficacy of the reverse-PPI trial in evaluating the presence of GERD or its recurrence rates, as well as to identify a correlation between the symptom recurrence rates and GERD severity determined by 48-hour Bravo esophageal pH-monitor testing. Methods: A final total of 205 patients that underwent the 48-hour Bravo esophageal pH-monitoring study were retrospectively included. Patients discontinued PPI usage for at least 7 days prior to testing, and completed symptom questionnaires during the 2-day test. The Bravo test was considered positive if the percentage of time with esophageal pH 4.4%. Results: A total of 363 patients underwent 48-hour Bravo testing and of those patients, 205 were eligible for the study. Ninety-two patients reported symptoms as being «same/better» and 113 as being «worse» after stopping PPIs. Of the 92 patients with improved symptoms, 44 (48% had documented acid reflux during the Bravo study, compared with 65 of 113 (58% patients with worsening symptoms that also complained of acid reflux. Of the 109 patients found to have confirmed GERD upon pH monitoring, 65 (59.6% reported a worsening of symptoms, compared with 48 of 96 (50.0% patients without GERD (p = 0.043. Main symptoms stated to be worse included heartburn, chest pain, regurgitation, nausea, and belching (p  7 days (p = 0.042 Conclusion: Symptom exacerbation following PPI cessation for at least 7 days correlated with acid reflux severity assessed by Bravo testing. Patients off PPIs for 7 days had a higher likelihood of experiencing worsening symptoms, compared with those off PPIs for more than 7 days. These findings suggest that when PPIs are held for 7 days or less prior to

  18. Development of urinary incontinence in a 7-year old boy after therapy with proton pump inhibitors and complete resolution of his clinicopathologic features of eosinophilic esophagitis after H2-receptor antagonist treatment: A case report

    Directory of Open Access Journals (Sweden)

    Rok Orel

    2017-06-01

    Full Text Available Background: Several diseases result in profound infltration of esophageal mucosa by eosinophilic granulocites, with gastroesophageal reflux disease (GERD, eosinophilic esophagitis (EoE and proton-pump-inhibitor-responsive esophageal eosinophilia (PPI-REE being the most prevalent. Proton-pump-inhibitor-responsive esophageal eosinophilia (PPI-REE is a newly recognized entity that must be differentiated from eosinophilic esophagitis (EoE.Case presentation: A 7-year old Slovenian male presented with a few-month history of chest pain, regurgitation and heartburn. First endoscopy was performed and revealed pronounced longitudinal furrows, and on hystology examination > 70 eosinophils per high power feld were found through the entire thickness of epithelium and in the submucosis with eosinophilic microabscess formation. Results of 24-hour pH-monitoring (without impedance monitoring excluded pathologic acid reflux. All allergy tests were negative. Te patient started treatment with proton pump inhibitors (PPIs for three times, twice with pantoprazole before the endoscopy and once with esomeprazole after it to exclude the diagnosis of GERD and PPI-REE. Urinary incontinence reappeared each time just few days after starting treatment and disappeared few days after stopping it. Therefore, urinary incontinence was considered as a plausible adverse effect of therapy with PPIs. As treatment with PPIs was not tolerated, a therapy with H2-receptor antagonists ranitidine was applied for more than 2 months followed by a second endoscopy. Both symptoms and esophageal eosinophilia completely resolved with ranitidine. The resolution of esophageal eosinophilia in PPI-REE has been attributed to proton pump independent antiinflammatory effects of PPIs. No such effects have been described in H2-receptor antagonists.Conclusions: Two unique phenomena were observed in the pediatric patient with profound esophageal eosinophilia: urinary incontinence as an adverse e

  19. Clopidogrel-Proton Pump Inhibitor Drug-Drug Interaction and Risk of Adverse Clinical Outcomes Among PCI-Treated ACS Patients: A Meta-analysis.

    Science.gov (United States)

    Serbin, Michael A; Guzauskas, Gregory F; Veenstra, David L

    2016-08-01

    Uncertainty regarding clopidogrel effectiveness attenuation because of a drug-drug interaction with proton pump inhibitors (PPI) has led to conflicting guidelines on concomitant therapy. In particular, the effect of this interaction in patients who undergo a percutaneous coronary intervention (PCI), a population known to have increased risk of adverse cardiovascular events, has not been systematically evaluated. To synthesize the evidence of the effect of clopidogrel-PPI drug interaction on adverse cardiovascular outcomes in a PCI patient population. We conducted a systematic literature review for studies reporting clinical outcomes in patients who underwent a PCI and were initiated on clopidogrel with or without a PPI. Studies were included in the analysis if they reported at least 1 of the clinical outcomes of interest (major adverse cardiovascular event [MACE], cardiovascular death, all-cause death, myocardial infarction, stroke, stent thrombosis, and bleed events). We excluded studies that were not exclusive to PCI patients or had no PCI subgroup analysis and/or did not report at least a 6-month follow-up. Statistical and clinical heterogeneity were evaluated and HRs and 95% CIs for adverse clinical events were pooled using the DerSimonian and Laird random-effects meta-analysis method. We identified 12 studies comprising 50,277 PCI patients that met our inclusion and exclusion criteria. Our analysis included retrospective analyses of randomized controlled trials (2), health registries (3), claims databases (2), and institutional records (5); no prospective studies of PCI patients were identified. On average, patients were in their mid-60s, male, and had an array of comorbidities, including hyperlipidemia, diabetes, hypertension, and smoking history. Concomitant therapy following PCI resulted in statistically significant increases in composite MACE (HR = 1.28; 95% CI = 1.24-1.32), myocardial infarction (HR = 1.51; 95% CI = 1.40-1.62), and stroke (HR = 1.46; 95

  20. Proton Transfer Dynamics at the Membrane/Water Interface: Dependence on the Fixed and Mobile pH Buffers, on the Size and Form of Membrane Particles, and on the Interfacial Potential Barrier

    Science.gov (United States)

    Cherepanov, Dmitry A.; Junge, Wolfgang; Mulkidjanian, Armen Y.

    2004-01-01

    Crossing the membrane/water interface is an indispensable step in the transmembrane proton transfer. Elsewhere we have shown that the low dielectric permittivity of the surface water gives rise to a potential barrier for ions, so that the surface pH can deviate from that in the bulk water at steady operation of proton pumps. Here we addressed the retardation in the pulsed proton transfer across the interface as observed when light-triggered membrane proton pumps ejected or captured protons. By solving the system of diffusion equations we analyzed how the proton relaxation depends on the concentration of mobile pH buffers, on the surface buffer capacity, on the form and size of membrane particles, and on the height of the potential barrier. The fit of experimental data on proton relaxation in chromatophore vesicles from phototropic bacteria and in bacteriorhodopsin-containing membranes yielded estimates for the interfacial potential barrier for H+/OH− ions of ∼120 meV. We analyzed published data on the acceleration of proton equilibration by anionic pH buffers and found that the height of the interfacial barrier correlated with their electric charge ranging from 90 to 120 meV for the singly charged species to >360 meV for the tetra-charged pyranine. PMID:14747306

  1. Synaptic Vesicle Endocytosis

    Science.gov (United States)

    Saheki, Yasunori; De Camilli, Pietro

    2012-01-01

    Neurons can sustain high rates of synaptic transmission without exhausting their supply of synaptic vesicles. This property relies on a highly efficient local endocytic recycling of synaptic vesicle membranes, which can be reused for hundreds, possibly thousands, of exo-endocytic cycles. Morphological, physiological, molecular, and genetic studies over the last four decades have provided insight into the membrane traffic reactions that govern this recycling and its regulation. These studies have shown that synaptic vesicle endocytosis capitalizes on fundamental and general endocytic mechanisms but also involves neuron-specific adaptations of such mechanisms. Thus, investigations of these processes have advanced not only the field of synaptic transmission but also, more generally, the field of endocytosis. This article summarizes current information on synaptic vesicle endocytosis with an emphasis on the underlying molecular mechanisms and with a special focus on clathrin-mediated endocytosis, the predominant pathway of synaptic vesicle protein internalization. PMID:22763746

  2. Factors affecting Helicobacter pylori eradication using a seven-day triple therapy with a proton pump inhibitor, tinidazole and clarithromycin, in brazilian patients with peptic ulcer Fatores que afetam a erradicação do Helicobacter pylori usando um tratamento triplo de sete dias com um inibidor de bomba de prótons associado ao tinidazol e a claritromicina, em pacientes brasileiros com úlcera péptica

    OpenAIRE

    Fernando Marcuz Silva; Schlioma Zaterka; Jaime Natan Eisig; Ethel Zimberg Chehter; Décio Chinzon; Antonio Atílio Laudanna

    2001-01-01

    Triple therapy is accepted as the treatment of choice for H. pylori eradication. In industrialized countries, a proton pump inhibitor plus clarithromycin and amoxicillin or nitroimidazole have shown the best results. Our aims were: 1. To study the eradication rate of the association of a proton pump inhibitor plus tinidazole and clarithromycin on H. pylori infection in our population. 2. To determine if previous treatments, gender, age, tobacco, alcohol use, and non-steroidal anti-inflammator...

  3. Preparation of large monodisperse vesicles.

    Directory of Open Access Journals (Sweden)

    Ting F Zhu

    Full Text Available Preparation of monodisperse vesicles is important both for research purposes and for practical applications. While the extrusion of vesicles through small pores (approximately 100 nm in diameter results in relatively uniform populations of vesicles, extrusion to larger sizes results in very heterogeneous populations of vesicles. Here we report a simple method for preparing large monodisperse multilamellar vesicles through a combination of extrusion and large-pore dialysis. For example, extrusion of polydisperse vesicles through 5-microm-diameter pores eliminates vesicles larger than 5 microm in diameter. Dialysis of extruded vesicles against 3-microm-pore-size polycarbonate membranes eliminates vesicles smaller than 3 microm in diameter, leaving behind a population of monodisperse vesicles with a mean diameter of approximately 4 microm. The simplicity of this method makes it an effective tool for laboratory vesicle preparation with potential applications in preparing large monodisperse liposomes for drug delivery.

  4. Proton therapy

    Science.gov (United States)

    Proton beam therapy; Cancer - proton therapy; Radiation therapy - proton therapy; Prostate cancer - proton therapy ... that use x-rays to destroy cancer cells, proton therapy uses a beam of special particles called ...

  5. Fusion of Nonionic Vesicles

    DEFF Research Database (Denmark)

    Bulut, Sanja; Oskolkova, M. Z.; Schweins, R.

    2010-01-01

    We present an experimental study of vesicle fusion using light and neutron scattering to monitor fusion events. Vesicles are reproducibly formed with an extrusion procedure using an single amphiphile triethylene glycol mono-n-decyl ether in water. They show long-term stability for temperatures ar...... a barrier to fusion changing from 15 k(B)T at T = 26 degrees C to 10k(H) T at T = 35 degrees C. These results are compatible with the theoretical predictions using the stalk model of vesicle fusion....

  6. Five-year examination of utilization and drug cost outcomes associated with benefit design changes including reference pricing for proton pump inhibitors in a state employee health plan.

    Science.gov (United States)

    Johnson, Jill T; Neill, Kathryn K; Davis, Dwight A

    2011-04-01

    The Arkansas State Employee Benefits Division (EBD) is a self-insured program comprising public school and other state employees, their spouses, and dependents. Previous research published in JMCP (2006) showed drug cost savings of $2.20 per member per month (PMPM; 37.6%) or annualized savings of $3.4 million associated with a benefit design change and coverage of the proton pump inhibitor (PPI) omeprazole over-the-counter (OTC) beginning in March 2004. On May 1, 2005, brand esomeprazole was excluded from coverage, with current users grandfathered for 4 months until September 2005. Reference pricing for PPIs, including esomeprazole but excluding generic omeprazole, was implemented on September 1, 2005, and the beneficiary cost share for all PPIs except generic omeprazole was determined from comparison of the PPI actual price to the $0.90 omeprazole OTC reference price per unit. To examine PPI utilization and drug costs before and after (a) excluding esomeprazole from coverage (with grandfathering current users) and (b) implementing a therapeutic maximum allowable cost (TMAC), or reference-pricing benefit design, for the PPI class in a large state employee health plan with fairly stable enrollment of approximately 127,500 members in 2005 through 2008 and approximately 128,000 members in 2009 Q1. The pharmacy claims database for the EBD was used to examine utilization and cost data for PPIs in a longitudinal analysis for the 61-month period from March 1, 2004, through March 31, 2009. Pharmacy claims data were compared for the period 14 months prior to esomeprazole exclusion (preperiod), 4 months during the esomeprazole exclusion (postperiod 1), and the ensuing 43 months of PPI reference pricing (postperiod 2). PPI cost and utilization data for the intervention group of approximately 127,500 beneficiaries were compared with a group of 122 self-insured employers with a total of nearly 1 million beneficiaries whose pharmacy benefits did not include reference pricing for

  7. Modeling and optimization of a heat-pump-assisted high temperature proton exchange membrane fuel cell micro-combined-heat-and-power system for residential applications

    DEFF Research Database (Denmark)

    Arsalis, Alexandros; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2015-01-01

    In this study a micro-combined-heat-and-power (micro-CHP) system is coupled to a vapor-compression heat pump to fulfill the residential needs for heating (space heating and water heating) and electricity in detached single-family households in Denmark. Such a combination is assumed to be attractive...... for application, since both fuel cell technology and electric heat pumps are found to be two of the most efficient technologies for generation/conversion of useful energy. The micro-CHP system is fueled with natural gas and includes a fuel cell stack, a fuel processor and other auxiliary components. The micro....... The variational loads are considered from full to quarter load, and the micro-CHP system is optimized in terms of operating thermophysical parameters for every different load. The results clearly indicate the capability of the proposed system to perform efficiently throughout all necessary load changes to fulfill...

  8. Penis Pump

    Science.gov (United States)

    ... appointment might be less involved. Choosing a penis pump Some penis pumps are available without a prescription, ... doesn't get caught in the ring. Penis pumps for penis enlargement Many advertisements in magazines and ...

  9. Centrifugal pumps

    CERN Document Server

    Anderson, HH

    1981-01-01

    Centrifugal Pumps describes the whole range of the centrifugal pump (mixed flow and axial flow pumps are dealt with more briefly), with emphasis on the development of the boiler feed pump. Organized into 46 chapters, this book discusses the general hydrodynamic principles, performance, dimensions, type number, flow, and efficiency of centrifugal pumps. This text also explains the pumps performance; entry conditions and cavitation; speed and dimensions for a given duty; and losses. Some chapters further describe centrifugal pump mechanical design, installation, monitoring, and maintenance. The

  10. How pure are your vesicles?

    Science.gov (United States)

    Webber, Jason; Clayton, Aled

    2013-01-01

    We propose a straightforward method to estimate the purity of vesicle preparations by comparing the ratio of nano-vesicle counts to protein concentration, using tools such as the increasingly available NanoSight platform and a colorimetric protein assay such as the BCA-assay. Such an approach is simple enough to apply to every vesicle preparation within a given laboratory, assisting researchers as a routine quality control step. Also, the approach may aid in comparing/standardising vesicle purity across diverse studies, and may be of particular importance in evaluating vesicular biomarkers. We herein propose some criteria to aid in the definition of pure vesicles. PMID:24009896

  11. Optically pumped polarized ion sources

    Energy Technology Data Exchange (ETDEWEB)

    Zelenski, A.N.

    1995-12-31

    Polarization transfer collisions between protons, atomic hydrogen, or deuterium and optically pumped alkali-metal vapour are implemented in the high current optically pumped polarized ion source (OPPIS) and the laser driven source (LDS) of nuclear polarized atoms for target applications. The OPPIS technique overcomes the limitations on intensity of the conventional atomic beam source technique and meets the requirements of the new generation of polarization experiments at multi-GeV accelerators and colliders. 17 refs., 3 figs.

  12. Long-term Use of Proton Pump Inhibitors Is Associated With Increased Microbial Product Translocation, Innate Immune Activation, and Reduced Immunologic Recovery in Patients With Chronic Human Immunodeficiency Virus-1 Infection.

    Science.gov (United States)

    Serpa, J A; Rueda, A M; Somasunderam, A; Utay, N S; Lewis, D; Couturier, J P; Breaux, K G; Rodriguez-Barradas, M

    2017-10-30

    Translocation of microbial products from the damaged gut causes increased immune activation in human immunodeficiency virus (HIV). Proton pump inhibitors (PPIs) predispose to bacterial overgrowth in the gut. We hypothesized that long-term use of PPIs is associated with greater microbial translocation and immune activation in HIV. HIV-infected persons on suppressive antiretroviral therapy (ART), including those receiving long-term PPIs (PPI+ group) or not (PPI- group), were enrolled. We determined CD38+HLA-DR+CD8+ (activated) T-cell frequency, and plasma levels of lipopolysaccharide (LPS), LPS binding protein (LBP), soluble CD14 (sCD14), and intestinal fatty acid binding protein (I-FABP). We recruited 77 HIV-infected participants (37 PPI+ and 40 PPI-) and 20 HIV-uninfected volunteers. PPI+ subjects were older and more likely to have hypertension and receive statins than PPI-. Nadir and enrollment CD4 counts, activated T-cells, and time on ART were similar in both groups. PPI+ group had higher sCD14 (2.15 vs. 1.50 mcg/mL, P immune activation and microbial translocation biomarkers than uninfected volunteers. In HIV, long-term use of PPIs was associated with increased microbial translocation, innate immune activation, and reduced immune reconstitution. Further studies are needed to evaluate the clinical implications of our findings. In the meantime, cautious use of PPIs is advised.

  13. Luminescent Immunoprecipitation System (LIPS) for Detection of Autoantibodies Against ATP4A and ATP4B Subunits of Gastric Proton Pump H+,K+-ATPase in Atrophic Body Gastritis Patients

    Science.gov (United States)

    Lahner, Edith; Brigatti, Cristina; Marzinotto, Ilaria; Carabotti, Marilia; Scalese, Giulia; Davidson, Howard W; Wenzlau, Janet M; Bosi, Emanuele; Piemonti, Lorenzo; Annibale, Bruno; Lampasona, Vito

    2017-01-01

    Objectives: Circulating autoantibodies targeting the H+/K+-ATPase proton pump of gastric parietal cells are considered markers of autoimmune gastritis, whose diagnostic accuracy in atrophic body gastritis, the pathological lesion of autoimmune gastritis, remains unknown. This study aimed to assess autoantibodies against ATP4A and ATP4B subunits of parietal cells H+, K+-ATPase in atrophic body gastritis patients and controls. Methods: One-hundred and four cases with atrophic body gastritis and 205 controls were assessed for serological autoantibodies specific for ATP4A or ATP4B subunits using luminescent immunoprecipitation system (LIPS). Recombinant luciferase-reporter-fused-antigens were expressed by in vitro transcription-translation (ATP4A) or after transfection in Expi293F cells (ATP4B), incubated with test sera, and immune complexes recovered using protein-A-sepharose. LIPS assays were compared with a commercial enzyme immunoassay (EIA) for parietal cell autoantibodies. Results: ATP4A and ATP4B autoantibody titers were higher in cases compared to controls (Pgastritis. Both assays had the highest sensitivity, at the cost of diagnostic accuracy (89 and 90% specificity), outperforming traditional EIA. Once validated, these LIPS assays should be valuable screening tools for detecting biomarkers of damaged atrophic oxyntic mucosa. PMID:28102858

  14. Clinical Characteristics of Patients with Gastroesophageal Reflux Disease Refractory to Proton Pump Inhibitors and the Effects of Switching to 20 mg Esomeprazole on Reflux Symptoms and Quality of Life.

    Science.gov (United States)

    Takeshima, Fuminao; Hashiguchi, Keiichi; Onitsuka, Yasunori; Tanigawa, Ken; Minami, Hitomi; Matsushima, Kayoko; Akazawa, Yuko; Shiozawa, Ken; Yamaguchi, Naoyuki; Taura, Naota; Ohnita, Ken; Ichikawa, Tatsuki; Isomoto, Hajime; Nakao, Kazuhiko

    2015-12-31

    BACKGROUND Refractory gastroesophageal reflux disease (GERD) may deteriorate patient quality of life (QOL) despite proton pump inhibitor (PPI) therapy. MATERIAL AND METHODS Nineteen Japanese institutions were surveyed to determine the clinical characteristics and QOL of patients with refractory GERD. Those patients treated with a conventional PPI were switched to 20 mg esomeprazole for 4 weeks. Symptoms and QOL were assessed using Global Overall Symptom and Gastrointestinal Symptom Rating Scale (GSRS) questionnaires at baseline and at 2 and/or 4 weeks of esomeprazole treatment. RESULTS Of 120 patients who completed the survey, 58 (48.3%) had refractory GERD. Of these, 69.0% were aged ≥ 65 years, 79.3% were prescribed a PPI at a standard or high dose, and 22.4% were prescribed a PPI together with another drug. After switching to esomeprazole, patients reported significant improvements in heartburn, acid regurgitation, and excessive belching at 2 weeks using a symptom diary, as well as the total score, reflux, abdominal pain, and indigestion, which were assessed using the GSRS at 4 weeks. CONCLUSIONS About half of Japanese patients with GERD may be refractory to conventional PPIs. Their reflux-related symptoms are often severe and may impair QOL. Switching to esomeprazole could be used to improve their symptoms and QOL.

  15. Heat pumps

    CERN Document Server

    Macmichael, DBA

    1988-01-01

    A fully revised and extended account of the design, manufacture and use of heat pumps in both industrial and domestic applications. Topics covered include a detailed description of the various heat pump cycles, the components of a heat pump system - drive, compressor, heat exchangers etc., and the more practical considerations to be taken into account in their selection.

  16. Heat pumps

    CERN Document Server

    Brodowicz, Kazimierz; Wyszynski, M L; Wyszynski

    2013-01-01

    Heat pumps and related technology are in widespread use in industrial processes and installations. This book presents a unified, comprehensive and systematic treatment of the design and operation of both compression and sorption heat pumps. Heat pump thermodynamics, the choice of working fluid and the characteristics of low temperature heat sources and their application to heat pumps are covered in detail.Economic aspects are discussed and the extensive use of the exergy concept in evaluating performance of heat pumps is a unique feature of the book. The thermodynamic and chemical properties o

  17. Proton pump inhibitors in gastroesophageal reflux disease: a custom-tailored therapeutic regimen Diseñando un traje a la medida: los inhibidores de la bomba de protones en la enfermedad por reflujo gastroesofágico

    Directory of Open Access Journals (Sweden)

    Sergio Sobrino-Cossío

    2012-07-01

    Full Text Available The Montreal Definition and Classification divides Gastroesophageal Reflux Disease (GERD into esophageal symptomatic syndromes (and with mucosal damage and extraesophageal syndromes (with acid established association and proposed association. In typical GERD symptoms, an 8-week treatment with PPIs is satisfactory in most cases (> 90%. Response rates to PPIs in GERD are highly variable, as they also rely on an appropriate clinical diagnosis of the disease; endoscopy differentiates the macroscopic GERD phenotype. The non-erosive variety (50-70% prevalence has a different symptomatic response rate, as gastric acid is not the sole etiology of symptoms. The possible explanations of treatment failure include treatment adherence, PPI metabolism alterations and characteristics, and inadequate diagnosis. Refractory symptoms are related to gastric content neutralization by the chronic use of PPIs. Extraesophageal manifestations are associated with other pathophysiological mechanisms where an autonomic nervous system disturbance gives rise to symptoms. In these clinical entities, the relationship between symptoms and acid needs to be established in order to determine the use of PPIs, or consider other drugs. In other words, so as to "custom-tailor the best-fitting therapy" we need to answer the questions for whom, for what, how and for how long. Finally, PPI safety and tolerability are factors to be considered in elderly patients requiring chronic PPI use, who usually have chronic concomitant illnesses.La Clasificación de Montreal divide la enfermedad por reflujo gastro-esofágico (ERGE en síndromes esofágicos sintomáticos y con daño a la mucosa y en síndromes extraesofágicos con asociación establecida al ácido y asociación propuesta. En síntomas ERGE típicos el tratamiento con inhibidores de la bomba de protones (IBP es satisfactorio (> 90% a 8 semanas en la mayoría de los casos. Las tasas de respuesta a los IBP en la ERGE son muy variables

  18. The toolbox of vesicle sidedness determination

    NARCIS (Netherlands)

    Meszaros, Peter; Hoekstra, Dick; Kok, Jan Willem

    2012-01-01

    Vesicles prepared from cellular plasma membranes are widely used in science for different purposes. The outer membrane leaflet differs from the inner membrane leaflet of the vesicle, and during vesicle preparation procedures two types of vesicles will be generated: right-side-out vesicles, of which

  19. Vesicles and vesicle gels - structure and dynamics of formation

    CERN Document Server

    Gradzielski, M

    2003-01-01

    Vesicles constitute an interesting morphology formed by self-aggregating amphiphilic molecules. They exhibit a rich structural variety and are of interest both from a fundamental point of view (for studying closed bilayer systems) and from a practical point of view (whenever one is interested in the encapsulation of active molecules). In many circumstances vesicular structures have to be formed by external forces, but of great interest are amphiphilic systems, where they form spontaneously. Here the question arises of whether this means that they are also thermodynamically stable structures, which at least in some systems appears to be the case. If such vesicles are well defined in size, it is possible to pack them densely and thereby form vesicle gels that possess highly elastic properties even for relatively low volume fractions of amphiphile. Conditions for the formation and the microstructure of such vesicle gels have been studied in some detail for the case of unilamellar vesicles. Another important and ...

  20. Ten-Day Quadruple Therapy Comprising Proton Pump Inhibitor, Bismuth, Tetracycline, and Levofloxacin is More Effective than Standard Levofloxacin Triple Therapy in the Second-Line Treatment of Helicobacter pylori Infection: A Randomized Controlled Trial.

    Science.gov (United States)

    Hsu, Ping-I; Tsai, Feng-Woei; Kao, Sung-Shuo; Hsu, Wen-Hung; Cheng, Jin-Shiung; Peng, Nan-Jing; Tsai, Kuo-Wang; Hu, Huang-Ming; Wang, Yao-Kuang; Chuah, Seng-Kee; Chen, Angela; Wu, Deng-Chyang

    2017-09-01

    Proton pump inhibitor (PPI)-amoxicillin-fluoroquinolone triple therapy is recommended as a second-line treatment of Helicobacter pylori infection in the Maastricht V/Florence Consensus Report. However, the eradication rate of this standard salvage treatment is suboptimal. The objective of this study is to compare the efficacy of esomeprazole-bismuth-tetracycline-levofloxacin therapy (TL quadruple therapy) and esomeprazole-amoxicillin-levofloxacin triple therapy (AL triple therapy) in rescue treatment for H. pylori infection. Consecutive H. pylori-infected subjects after failure of first-line therapies were randomly allocated to receive either TL quadruple therapy (esomeprazole 40 mg b.d., bismuth 120 mg q.d.s., tetracycline 500 mg q.d.s., and levofloxacin 500 mg o.d.) or AL triple therapy (esomeprazole 40 mg b.d., amoxicillin 500 mg q.d.s., and levofloxacin 500 mg o.d.) for 10 days. H. pylori status was assessed 6 weeks after the end of treatment. The study was stopped after an interim analysis. Of 50 patients in the TL quadruple therapy, 49 (98.0%) had successful eradication of H. pylori infection. Cure of H. pylori infection was achieved in 36 of 52 patients (69.2%) receiving AL triple therapy. Intention-to-treat analysis demonstrated that TL quadruple therapy achieved a markedly higher eradication rate than AL triple therapy (difference: 28.8%; 95% confidence interval: 15.7% to 41.9%; Pbismuth quadruple therapy (95.0% vs. 52.6%; P=0.003). Ten-day PPI-bismuth-tetracycline-levofloxacin quadruple therapy is a good option for rescue treatment of H. pylori infection following failure of standard triple or non-bismuth quadruple therapy.

  1. Efficacy and safety of twice-daily rabeprazole maintenance therapy for patients with reflux esophagitis refractory to standard once-daily proton pump inhibitor: the Japan-based EXTEND study.

    Science.gov (United States)

    Kinoshita, Yoshikazu; Kato, Mototsugu; Fujishiro, Mitsuhiro; Masuyama, Hironori; Nakata, Ryo; Abe, Hisanori; Kumagai, Shinji; Fukushima, Yasushi; Okubo, Yoshiumi; Hojo, Seiichiro; Kusano, Motoyasu

    2017-11-29

    Rabeprazole at 10 or 20 mg twice daily (b.i.d.) has been reported to be highly effective in the treatment of proton pump inhibitor (PPI)-resistant reflux esophagitis (RE) that is refractory to the standard once-daily PPI regimen. We evaluated the efficacy and safety of rabeprazole maintenance therapy at 10 mg once daily (q.d.) or b.i.d. for longer than 8 weeks. Patients with RE refractory to standard PPI regimens for at least 8 weeks were enrolled. They were treated with rabeprazole at 10 or 20 mg b.i.d. for 8 weeks during the open-label treatment period. After endoscopic examination, those with confirmed healing entered the subsequent double-blind maintenance therapy. During this period, the subjects were randomized to receive rabeprazole 10 mg q.d. (control) or 10 mg b.i.d. The primary endpoint was the endoscopic no-recurrence rate at Week 52. In total, 517 subjects entered the treatment, and 359 subjects continued on maintenance therapy. The full analysis set for central assessment included 343 subjects. The no-recurrence rate at Week 52 was significantly higher in the b.i.d. group (73.9%; p maintenance treatment of PPI-resistant RE, rabeprazole at 10 mg b.i.d. exerted a stronger recurrence-preventing effect than 10 mg q.d. over 52 weeks. No particular safety issues were noted during long-term administration. ClinicalTrials.gov number: NCT02135107.

  2. Is the concomitant use of clopidogrel and Proton Pump Inhibitors still associated with increased adverse cardiovascular outcomes following coronary angioplasty?: a systematic review and meta-analysis of recently published studies (2012 - 2016).

    Science.gov (United States)

    Bundhun, Pravesh Kumar; Teeluck, Abhishek Rishikesh; Bhurtu, Akash; Huang, Wei-Qiang

    2017-01-05

    Controversies were previously observed with the concomitant use of clopidogrel and Proton Pump Inhibitors (PPIs), especially omeprazole, following coronary angioplasty. Even though several studies showed no interaction between clopidogrel and PPIs, questions have been raised about the decrease in antiplatelet effects of clopidogrel with PPIs. A previously published meta-analysis showed concomitant use of clopidogrel and PPIs to be associated with higher adverse cardiovascular outcomes. However, data which were used were extracted from studies published before the year 2012. Whether these controversies still exist in this new era is not clear. Therefore, we aim to show if the concomitant use of clopidogrel and PPIs is still associated with higher adverse outcomes following Percutaneous Coronary Intervention (PCI) using data obtained from recently published studies (2012 to 2016). Electronic databases were searched for recent publications (2012-2016) comparing (clopidogrel plus PPIs) versus clopidogrel alone following PCI. Adverse cardiovascular outcomes were considered as the clinical endpoints. Odds Ratios (OR) with 95% Confidence Intervals (CI) were used as the statistical parameters and the pooled analyses were performed with RevMan 5.3 software. Eleven studies with a total number of 84,729 patients (29,235 patients from the PPIs group versus 55,494 patients from the non-PPIs group) were included. Results of this analysis showed that short term mortality and Target Vessel Revascularization (TVR) significantly favored the non-PPIs group with OR: 1.55; 95% CI: 1.43-1.68, P clopidogrel with PPIs is still associated with significantly higher adverse cardiovascular events such as MACEs, ST and MI following PCI supporting results of the previously published meta-analysis. However, long-term mortality is not statistically significant warranting further analysis with randomized patients.

  3. Preeclampsia and Extracellular Vesicles.

    Science.gov (United States)

    Gilani, Sarwat I; Weissgerber, Tracey L; Garovic, Vesna D; Jayachandran, Muthuvel

    2016-09-01

    Preeclampsia is a hypertensive pregnancy disorder characterized by development of hypertension and proteinuria after 20 weeks of gestation that remains a leading cause of maternal and neonatal morbidity and mortality. While preeclampsia is believed to result from complex interactions between maternal and placental factors, the proximate pathophysiology of this syndrome remains elusive. Cell-to-cell communication is a critical signaling mechanism for feto-placental development in normal pregnancies. One mechanism of cellular communication relates to activated cell-derived sealed membrane vesicles called extracellular vesicles (EVs). The concentrations and contents of EVs in biological fluids depend upon their cells of origin and the stimuli which trigger their production. Research on EVs in preeclampsia has focused on EVs derived from the maternal vasculature (endothelium, vascular smooth muscle) and blood (erythrocytes, leukocytes, and platelets), as well as placental syncytiotrophoblasts. Changes in the concentrations and contents of these EVs may contribute to the pathophysiology of preeclampsia by accentuating the pro-inflammatory and pro-coagulatory states of pregnancy. This review focuses on possible interactions among placental- and maternal-derived EVs and their contents in the initiation and progression of the pathogenesis of preeclampsia. Understanding the contributions of EVs in the pathogenesis of preeclampsia may facilitate their use as diagnostic and prognostic biomarkers.

  4. Centrifugal pumps

    CERN Document Server

    Gülich, Johann Friedrich

    2014-01-01

    This book gives an unparalleled, up-to-date, in-depth treatment of all kinds of flow phenomena encountered in centrifugal pumps including the complex interactions of fluid flow with vibrations and wear of materials. The scope includes all aspects of hydraulic design, 3D-flow phenomena and partload operation, cavitation, numerical flow calculations, hydraulic forces, pressure pulsations, noise, pump vibrations (notably bearing housing vibration diagnostics and remedies), pipe vibrations, pump characteristics and pump operation, design of intake structures, the effects of highly viscous flows, pumping of gas-liquid mixtures, hydraulic transport of solids, fatigue damage to impellers or diffusers, material selection under the aspects of fatigue, corrosion, erosion-corrosion or hydro-abrasive wear, pump selection, and hydraulic quality criteria. As a novelty, the 3rd ed. brings a fully analytical design method for radial impellers, which eliminates the arbitrary choices inherent to former design procedures. The d...

  5. Pumping life

    DEFF Research Database (Denmark)

    Sitsel, Oleg; Dach, Ingrid; Hoffmann, Robert Daniel

    2012-01-01

    The name PUMPKIN may suggest a research centre focused on American Halloween traditions or the investigation of the growth of vegetables – however this would be misleading. Researchers at PUMPKIN, short for Centre for Membrane Pumps in Cells and Disease, are in fact interested in a large family o......’. Here we illustrate that the pumping of ions means nothing less than the pumping of life....

  6. Protons Regulate Vesicular Glutamate Transporters through an Allosteric Mechanism.

    Science.gov (United States)

    Eriksen, Jacob; Chang, Roger; McGregor, Matt; Silm, Katlin; Suzuki, Toshiharu; Edwards, Robert H

    2016-05-18

    The quantal nature of synaptic transmission requires a mechanism to transport neurotransmitter into synaptic vesicles without promoting non-vesicular efflux across the plasma membrane. Indeed, the vesicular transport of most classical transmitters involves a mechanism of H(+) exchange, which restricts flux to acidic membranes such as synaptic vesicles. However, vesicular transport of the principal excitatory transmitter glutamate depends primarily on membrane potential, which would drive non-vesicular efflux, and the role of protons is unclear. Adapting electrophysiology to record currents associated with the vesicular glutamate transporters (VGLUTs), we characterize a chloride conductance that is gated by lumenal protons and chloride and supports glutamate uptake. Rather than coupling stoichiometrically to glutamate flux, lumenal protons and chloride allosterically activate vesicular glutamate transport. Gating by protons serves to inhibit what would otherwise be substantial non-vesicular glutamate efflux at the plasma membrane, thereby restricting VGLUT activity to synaptic vesicles. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Proton pumping accompanies calcification in foraminifera

    NARCIS (Netherlands)

    Toyofuku, Takashi; Matsuo, Miki Y.; de Nooijer, Lennart Jan; Nagai, Yukiko; Kawada, Sachiko; Fujita, Kazuhiko; Reichart, Gert-Jan; Nomadi, Hidetaka; Tsuchiya, Masashi; Sakaguchi, Hide; Kitazato, Hiroshi

    2017-01-01

    Ongoing ocean acidification is widely reported to reduce the ability of calcifying marine organisms to produce their shells and skeletons. Whereas increased dissolution due to acidification is a largely inorganic process, strong organismal control over biomineralization influences calcification and

  8. Inside view of a giant proton pump

    NARCIS (Netherlands)

    Brandt, U.

    2013-01-01

    Inner workings: The X-ray crystal structure of the entire bacterial complex I at 3.3 A resolution offers fascinating insights into a giant 536 kDa molecular machine. The respiratory chain complex seems to employ unique mechanisms of energetic coupling that are entirely different from those found in

  9. The rate of prescribing gastrointestinal prophylaxis with either a proton pump inhibitor or an H2-receptor antagonist in Nova Scotia seniors starting nonsteroidal anti-inflammatory drug therapy.

    Science.gov (United States)

    Superceanu, Bogdan; Veldhuyzen van Zanten, Sander; Skedgel, Chris; Shepherd, Michael; Sketris, Ingrid

    2010-08-01

    Nonsteroidal anti-inflammatory drugs (NSAIDs) are widely used agents that can cause serious gastrointestinal (GI) side effects. For patients at increased risk of NSAID-related GI complications, prophylaxis with either a nonselective NSAID plus gastroprotective agent (GPA) or, alternatively, therapy with a cyclooxygenase-2 selective inhibitor with or without a GPA such as a proton pump inhibitor (PPI), is recommended. To describe the rate, timing and duration of GI prophylaxis in Nova Scotia seniors receiving nonselective NSAIDs. The Nova Scotia Seniors' Pharmacare Program beneficiaries for the years 1998 to 2002 were studied. A cohort of incident NSAID and GPA users was selected from all nonselective NSAID users (no prescribed NSAID dispensed 12 months before the index month and no GPA dispensed two months before the index prescription). Monthly coprescribing rates were calculated by dividing the number of patients in the cohort using GPAs by the number of NSAID users. GI prophylactic coprescribing was defined as the coprescribing rate present at the first month (index month) of prescribing an NSAID. The cohort consisted of 12,906 patients. Seventy-five per cent of the nonselective NSAID prescriptions dispensed were for up to two months duration, with only 2.3% longer than one year. GI prophylaxis was given to only 3.8% of patients starting NSAIDs who were not on a GPA in the two months before starting NSAIDs. Of this 3.8%, 92.7% of the patients received H2-receptor antagonists (H2RAs), and 7% received PPIs. The rate of H2RA coprescribing increased with the number of consecutive months on an NSAID from 3.5% in the first month to 24.1% at 48 months. For PPIs, the coprescribing rate increased from 0.3% to 1.9% of all NSAID users in the cohort. The rate of gastroprophylaxis coprescribing for patients receiving NSAIDs did not rise with increasing age. In Nova Scotian seniors using nonselective NSAIDs, the rate of GI prophylaxis was low. Most patients received H2RAs as

  10. Effects of CYP2C19 loss-of-function variants on the eradication of H. pylori infection in patients treated with proton pump inhibitor-based triple therapy regimens: a meta-analysis of randomized clinical trials.

    Directory of Open Access Journals (Sweden)

    Hui-Lin Tang

    Full Text Available There are inconsistent conclusions about whether CYP2C19 variants could affect H. pylori eradication rate in patients treated with the proton pump inhibitor (PPI-based therapy. We therefore performed a meta-analysis of randomized clinical trials (RCTs to re-evaluate the impact of CYP2C19 variants on PPI-based triple therapy for the above indication.All relevant RCTs in the PubMed, Cochrane Library, EMBASE, Web of Science and two Chinese databases (up to February 2013 were systematically searched, and a pooled analysis was performed with the odds ratio (OR and 95% confidence interval (CI by the STATA software.Sixteen RCT datasets derived from 3680 patients were included. There was no significant heterogeneity across the data available in this meta-analysis. There were significant differences in that rate between homozygous (HomEMs and heterozygous (HetEMs extensive metabolizers (OR 0.724; 95% CI 0.594-0.881, between HomEMs and poor metabolizers (PM (OR 0.507; 95%CI 0.379-0.679, or between HetEMs and PMs (OR 0.688; 95%CI 0.515-0.920, regardless of the PPI being taken. Furthermore, sub-analysis of individual PPIs was carried out to explore the difference across all the PPIs used. A significantly low rate was seen in HomEMs vs. HetEMs taking either omeprazole (OR 0.329; 95%CI 0.195-0.553 or lansoprazole (OR 0.692; 95%CI 0.485-0.988, and also in HomEMs vs. PMs for omeprazole (OR 0.232; 95%CI 0.105-0.515 or lansoprazole (OR 0.441; 95%CI 0.252-0.771. However, there was no significant difference between HetEMs and PMs taking either one. No significant differences were observed for rabeprazole or esomeprazole across the CYP2C19 genotypes of interest.Carriage of CYP2C19 loss-of-function variants is associated with increased H. pylori eradication rate in patients taking PPI-based triple therapies when omeprazole or lansoprazole is chosen. However, there is no a class effect after use of rabeprazole or esomeprazole.

  11. Extracellular Vesicles in Cardiovascular Theranostics

    OpenAIRE

    Bei, Yihua; Das, Saumya; Rodosthenous, Rodosthenis S.; Holvoet, Paul; Vanhaverbeke, Maarten; Monteiro,Marta Chagas; Monteiro, Valter Vinicius Silva; Radosinska, Jana; Bartekova, Monika; Jansen, Felix; Li, Qian; Rajasingh, Johnson; Xiao, Junjie

    2017-01-01

    Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells. Increasing evidence has shown the important regulatory effects of EVs in cardiovascular diseases (CVDs). EVs secreted by cardiomyocytes, endothelial cells, fibroblasts, and stem cells pla...

  12. Immunotherapeutic Potential of Extracellular Vesicles

    OpenAIRE

    Zhang, Bin; Yin, Yijun; Lai, Ruenn Chai; Lim, Sai Kiang

    2014-01-01

    Extracellular vesicle or EV is a term that encompasses all classes of secreted lipid membrane vesicles. Despite being scientific novelties, EVs are gaining importance as a mediator of important physiological and pathological intercellular activities possibly through the transfer of their cargo of protein and RNA between cells. In particular, exosomes, the currently best characterized EVs have been notable for their in vitro and in vivo immunomodulatory activities. Exosomes are nanometer-sized...

  13. RNA in extracellular vesicles.

    Science.gov (United States)

    Kim, Kyoung Mi; Abdelmohsen, Kotb; Mustapic, Maja; Kapogiannis, Dimitrios; Gorospe, Myriam

    2017-07-01

    Cells release a range of membrane-enclosed extracellular vesicles (EVs) into the environment. Among them, exosomes and microvesicles (collectively measuring 40-1000 nm in diameter) carry proteins, signaling lipids, and nucleic acids from donor cells to recipient cells, and thus have been proposed to serve as intercellular mediators of communication. EVs transport cellular materials in many physiologic processes, including differentiation, stem cell homeostasis, immune responses, and neuronal signaling. EVs are also increasingly recognized as having a direct role in pathologies such as cancer and neurodegeneration. Accordingly, EVs have been the focus of intense investigation as biomarkers of disease, prognostic indicators, and even therapeutic tools. Here, we review the classes of RNAs present in EVs, both coding RNAs (messenger RNAs) and noncoding RNAs (long noncoding RNAs, microRNAs, and circular RNAs). The rising attention to EV-resident RNAs as biomarkers stems from the fact that RNAs can be detected at extremely low quantities using a number of methods. To illustrate the interest in EV biology, we discuss EV RNAs in cancer and neurodegeneration, two major age-associated disease processes. WIREs RNA 2017, 8:e1413. doi: 10.1002/wrna.1413 For further resources related to this article, please visit the WIREs website. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

  14. Extracellular Vesicles in Renal Pathophysiology.

    Science.gov (United States)

    Pomatto, Margherita A C; Gai, Chiara; Bussolati, Benedetta; Camussi, Giovanni

    2017-01-01

    Extracellular vesicles are a heterogeneous population of microparticles released by virtually all living cells which have been recently widely investigated in different biological fields. They are typically composed of two primary types (exosomes and microvesicles) and are recently commanding increasing attention as mediators of cellular signaling. Indeed, these vesicles can affect recipient cells by carrying and delivering complex cargos of biomolecules (including proteins, lipids and nucleic acids), protected from enzymatic degradation in the environment. Their importance has been demonstrated in the pathophysiology of several organs, in particular in kidney, where different cell types secrete extracellular vesicles that mediate their communication with downstream urinary tract cells. Over the past few years, evidence has been shown that vesicles participate in kidney development and normal physiology. Moreover, EVs are widely demonstrated to be implicated in cellular signaling during renal regenerative and pathological processes. Although many EV mechanisms are still poorly understood, in particular in kidney, the discovery of their role could help to shed light on renal biological processes which are so far elusive. Lastly, extracellular vesicles secreted by renal cells gather in urine, thus becoming a great resource for disease or recovery markers and a promising non-invasive diagnostic instrument for renal disease. In the present review, we discuss the most recent findings on the role of extracellular vesicles in renal physiopathology and their potential implication in diagnosis and therapy.

  15. Extracellular vesicles in renal disease.

    Science.gov (United States)

    Karpman, Diana; Ståhl, Anne-Lie; Arvidsson, Ida

    2017-09-01

    Extracellular vesicles, such as exosomes and microvesicles, are host cell-derived packages of information that allow cell-cell communication and enable cells to rid themselves of unwanted substances. The release and uptake of extracellular vesicles has important physiological functions and may also contribute to the development and propagation of inflammatory, vascular, malignant, infectious and neurodegenerative diseases. This Review describes the different types of extracellular vesicles, how they are detected and the mechanisms by which they communicate with cells and transfer information. We also describe their physiological functions in cellular interactions, such as in thrombosis, immune modulation, cell proliferation, tissue regeneration and matrix modulation, with an emphasis on renal processes. We discuss how the detection of extracellular vesicles could be utilized as biomarkers of renal disease and how they might contribute to disease processes in the kidney, such as in acute kidney injury, chronic kidney disease, renal transplantation, thrombotic microangiopathies, vasculitides, IgA nephropathy, nephrotic syndrome, urinary tract infection, cystic kidney disease and tubulopathies. Finally, we consider how the release or uptake of extracellular vesicles can be blocked, as well as the associated benefits and risks, and how extracellular vesicles might be used to treat renal diseases by delivering therapeutics to specific cells.

  16. Impulse Pump

    Science.gov (United States)

    2016-06-17

    links the flywheel to a pusher shaft. The energy release is achieved when the planetary gear carrier is decelerated using a caliper brake . The...flywheel. Through a cam roller contact point between the pusher shaft and the cam raceway on the plunger; the rotational motion of the pusher shaft... brakes , a barrel type cam and follower, a piston pump, a reservoir, and a nozzle to assemble the inventive pump. BRIEF DESCRIPTION OF THE DRAWINGS

  17. Uniport of monoanionic L-malate in membrane vesicles from Leuconostoc oenos

    NARCIS (Netherlands)

    SALEMA, M; POOLMAN, B; LOLKEMA, JS; DIAS, MCL; KONINGS, WN

    1994-01-01

    L-malate transport was studied in membrane vesicles from Leuconostoc oenos MLE(-) (mutant lacking malolactic enzyme) which were fused with liposomes containing beef heart cytochrome c oxidase as a proton-motive-force-generating system. In these hybrid membranes, accumulation of L-malate was observed

  18. Transport of Basic Amino Acids by Membrane Vesicles of Lactococcus lactis

    NARCIS (Netherlands)

    Driessen, Arnold J.M.; Leeuwen, Cornelis van; Konings, Wilhelmus

    The uptake of the basic amino acids arginine, ornithine, and lysine was studied in membrane vesicles derived from cells of Lactococcus lactis which were fused with liposomes in which beef heart mitochondrial cytochrome c oxidase was incorporated as a proton motive force (PMF)-generating system. In

  19. Efficacy of triple therapy with a proton pump inhibitor, levofloxacin, and amoxicillin as first-line treatment to eradicate Helicobacter pylori Eficacia de una triple terapia con un inhibidor de la bomba de protones, levofloxacino y amoxicilina, como primer tratamiento, en la erradicación de Helicobacter pylori

    Directory of Open Access Journals (Sweden)

    M. Castro-Fernández

    2009-06-01

    Full Text Available Background: triple therapy including a proton pump inhibitor, clarithromycin, and amoxicillin (PPI-CA is the first-choice treatment used for H. pylori eradication. The efficacy of this treatment is declining of late, and alternative therapies are currently under evaluation. Objectives: to evaluate the efficacy, safety and compliance of a triple therapy with a PPI, amoxicillin and levofloxacin (PPI-LA - replacing clarithromycin - for the eradication of H. pylori. Methods: the study included 135 patients (65% women, mean age 53 years, with dyspeptic symptoms and H. pylori infection proven by a positive urease rapid test, histological analysis, or C13-urea breath test. Diagnosis: non-investigated dyspepsia 48.9%, functional dyspepsia 36.3%, and ulcerative dyspepsia 14.8%. Treatment was indicated with a proton pump inhibitor at usual doses, amoxicillin 1 g, and levofloxacin 500 mg, administered jointly during breakfast and dinner for 10 days. We studied the performance of this triple therapy and its effects using a questionnaire, and effectiveness by the negativity of the C13-urea breath test after 6-8 weeks after treatment discontinuation. Per protocol, we compared the effectiveness of PPI-LA with a control group of 270 patients treated with PPI-CA for 10 days. Results: 130 patients (96.2% could complete the treatment and follow-up protocol. Effectiveness (intention to treat was 71.8% (97/135 and 74.6% (per protocol (97/130. Sixteen patients (11.8% had well-tolerated adverse effects, except for 5 subjects (3.7% who dropped out. PPI-CA was effective (per protocol in 204 patients out of 270 (75.5% in the control group. Conclusions: triple therapy with a PPI, amoxicillin and levofloxacin for 10 days is a well-tolerated treatment that is easy to comply with; however it has low efficiency - less than 80% - and is not recommended as a first-choice treatment for H. pylori eradication. Similar results were obtained with the classic triple therapy using a

  20. Kinetic vs. Thermodynamic Control of Bacteriorhodopsin Pumping

    Science.gov (United States)

    Gunner, Marilyn

    2011-03-01

    Bacteriorhodopsin is a transmembrane proton pump that converts light energy to a transmembrane electrochemical gradient. Retinal, bound in the center of the protein, absorbs light and isomerizes from the all-trans to 13-cis configuration. A series of conformational changes and proton transfers then restores the structure to the all-trans ground state while pumping one proton from the high pH cell interior to the low pH exterior, saving energy in an electrochemical gradient. Poorly understood gating elements control key steps where incorrect proton transfer would return the protein to the ground state without pumping. The gate's barrier height determines how much the pump leaks. Analysis of high-resolution structures trapped in different intermediates has produced ideas for how bacteriorhodopsin ensures pumping. There are two contrasting strategies, one primarily thermodynamic and the other relying on kinetic control to ensure that protons are moved uphill. With thermodynamic control, residue protonation states always remain in quasi-equilibrium. Relatively slow conformational changes shift the energy landscape modifying site pKas. Residues then change ionization remaining in equilibrium in each metastable intermediate. The sequence of intermediates imparts the directionality to the transfers. Alternatively, the direction of transfer is determined by the accessibility of low energy pathways so is thus is under kinetic control. We will discuss which steps in the bacteriorhodopsin photocycle are under thermodynamic or under kinetic control. The role of three specific conformational changes (retinal isomerization, Arg82 reorientation and Glu194 and 204 separations) on the degree of proton transfer will be described. Supported by NFS MCB 1022208. Carried out with Yifan Song now at the University of Washington Department of Biochemistry.

  1. Polymeric surfactant vesicles. Synthesis and characterization by nuclear magnetic resonance spectroscopy and dynamic laser light scattering

    Energy Technology Data Exchange (ETDEWEB)

    Kippenberger, D. (Texas A and M Univ., College Station); Rosenquist, K.; Odberg L.; Tundo, P.; Fendler, J.H.

    1983-03-09

    (CH/sub 3/(CH/sub 2/)/sub 15/)(CH/sub 2/==CH(CH/sub 2/)/sub 8/CONH(CH/sub 2/)/sub 6/)(CH/sub 3/)/sub 2/N/sup +/Br/sup -/(1),(CH/sub 3/(CH/sub 2/)/sub 14/CO/sub 2/(CH/sub 2/)/sub 2/)/sub 2/(CH/sub 3/)(CH/sub 2/CH==CH/sub 2/)N/sup +/Br/sup -/(2),(CH/sub 3/(CH/sub 2/)/sub 14/CO/sub 2/(CH/sub 2/)/sub 2/)/sub 2/NCOCH==CHCO/sub 2/H(3), and (CH/sub 3/(CH/sub 2/)/sub 17/)NCOCH==CHCO/sub 2/H(4) have been synthesized. Sonication of these surfactants led to the formation of vesicles. Vesicles could be polymerized by exposure to ultraviolet radiation or by the use of azoisobutyronitrile (AIBN) as an initiator. Vesicles prepared from 1 polymerized in their bilayers. Vesicles prepared from 2, 3, and 4 have double bonds on their headgroups and could, therefore, potentially polymerize both at the inner and outer surfaces or separately at either surface. Polymerization of vesicles prepared from 2, 3, and 4 by ultraviolet radiation resulted in the closing of both surfaces. Conversely, addition of AIBN to a solution of these vesicles and subsequent incubation at 80/sup 0/ led to the selective ''zipping-up'' of the outer surface only. Following the loss of vinyl protons of the surfactant vesicles by /sup 1/HNMR spectroscopy provided evidence for polymerization. Presence of vesicles has been demonstrated by substrate entrapment, gel filtration, and dynamic laser light scattering. Increasing the sonication time led to smaller and less polydisperse vesicles. On polymerization, vesicles maintaned the sizes of their nonpolymeric counterparts. Polymeric vesicles were found to be appreciably more stable than their unpolymerized analogues. Polymeric vesicles retained the fluidities of vesicles and underwent thermotropic phase transitions. Addition of KCl led to the growth of both unpolymerized and polymeric surfactant vesicles.

  2. Extracellular Vesicles in Lung Disease.

    Science.gov (United States)

    Kubo, Hiroshi

    2018-01-01

    Accumulating evidence suggests that extracellular vesicles (EVs) play a role in the pathogenesis of lung diseases. These vesicles include exosomes, ectosomes (ie, microparticles, extracellular vesicles, microvesicles, and shedding vesicles), and apoptotic bodies. Exosomes are generated by inward budding of the membrane (endocytosis), subsequent forming of multivesicular bodies, and release by exocytosis. Ectosomes are formed by outward blebbing from the plasma membrane and are then released by proteolytic cleavage from the cell surface. Apoptotic bodies are generated on apoptotic cell shrinkage and death. Extracellular vesicles are released when the cells are activated or undergo apoptosis under inflammatory conditions. The number and types of released EVs are different according to the pathophysiological status of the disease. Therefore, EVs can be novel biomarkers for various lung diseases. EVs contain several molecules, including proteins, mRNA, microRNA, and DNA; they transfer these molecules to distant recipient cells. Circulating EVs modify the targeted cells and influence the microenvironment of the lungs. For this unique capability, EVs are expected to be a new drug delivery system and a novel therapeutic target. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

  3. Partial purification of the ATP-driven calcium pump of Streptococcus sanguis

    Energy Technology Data Exchange (ETDEWEB)

    Lynn, A.R.; Rosen, B.P.

    1986-05-01

    ATP-dependent transport of calcium has been observed in several species of streptococci as uptake of /sup 45/Ca/sup 2 +/ into everted membrane vesicles. Membranes from Streptococcus sanguis and Streptococcus faecalis were solubilized with octyl-..beta..-D-glucoside or Triton X-100, and the extracts reconstituted into proteoliposomes containing Escherichia coli or soybean phospholipid. Calcium transport in reconstituted proteoliposomes was insensitive to the ionophores nigericin and valinomycin and was unaffected by the F/sub 0/F/sub 1/ inhibitor N,N'-dicyclohexylcarbodiimide. Uptake was inhibited by ortho-vanadate with a K/sub i/ in the micromolar range. These results demonstrate that the reconstituted transport activities are not the result of ATP-driven proton pumping via the F/sub 0/F/sub 1/ coupled to a calcium/proton antiporter and suggest that existence of a calcium translocating ATPase. Partial purification of the transport activity from Streptococcus sanguis has been achieved using density gradient centrifugation and FPLC.

  4. Electrokinetic pump

    Science.gov (United States)

    Hencken, Kenneth R.; Sartor, George B.

    2004-08-03

    An electrokinetic pump in which the porous dielectric medium of conventional electrokinetic pumps is replaced by a patterned microstructure. The patterned microstructure is fabricated by lithographic patterning and etching of a substrate and is formed by features arranged so as to create an array of microchannels. The microchannels have dimensions on the order of the pore spacing in a conventional porous dielectric medium. Embedded unitary electrodes are vapor deposited on either end of the channel structure to provide the electric field necessary for electroosmotic flow.

  5. Cystadenoma of the seminal vesicle

    Directory of Open Access Journals (Sweden)

    Gil Antônio O.

    2003-01-01

    Full Text Available Primary tumors of the seminal vesicle are extremely rare. Among them, there is a spectrum of tumors derived from both epithelium and stroma and so classified as epithelial-stromal tumors. Herein, we report a case of a cystadenoma in a 49-year-old asymptomatic man, detected in a routine ultrasonography for liver disease follow-up. The digital rectal examination detected a large mass anterior to rectum and posterior to bladder. Computed tomography scan and magnetic resonance imaging showed a normal prostate and a 9.0 cm cystic tumor, replacing the left seminal vesicle. The gross appearance and microscopic aspect was compatible with cystadenoma of seminal vesicle. Patient's postoperative recovery was uneventful. He is currently alive, 3 years after the diagnosis, with no signs of recurrence.

  6. When to biopsy seminal vesicles.

    Science.gov (United States)

    Panach-Navarrete, J; García-Morata, F; Hernández-Medina, J A; Martínez-Jabaloyas, J M

    2015-05-01

    The involvement of seminal vesicles in prostate cancer can affect the prognosis and determine the treatment. The objective of this study was to determine whether we could predict its infiltration at the time of the prostate biopsy to know when to indicate the biopsy of the seminal vesicles. observational retrospective study of 466 patients who underwent seminal vesicle biopsy. The indication for this biopsy was a prostate-specific antigen (PSA) level greater than 10 ng/ml or an asymmetric or obliterated prostatoseminal angle. The following variables were included in the analysis: PSA level, PSA density, prostate volume, number of cores biopsied, suspicious rectal examination, and preservation of the prostatoseminal angle, studying its relationship with the involvement of the seminal vesicles. Forty-one patients (8.8%) had infiltrated seminal vesicles and 425 (91.2%) had no involvement. In the univariate analysis, the cases with infiltration had a higher mean PSA level (P 19.60 ng/dL (P < .01) and 2.95 times higher if there is a suspicious rectal examination (P = .014). Furthermore, this probability increases by 1.04 times for each unit of prostate volume lower (P < .01). The ROC curves showed maximum sensitivity and specificity at 19.6 ng/mL for PSA and 0.39 for PSA density. In this series, greater involvement of seminal vesicles was associated with a PSA level ≥20 ng/ml, a suspicious rectal examination and a lack of prostatoseminal angle preservation. Copyright © 2014 AEU. Publicado por Elsevier España, S.L.U. All rights reserved.

  7. Protonated nitrosamide

    DEFF Research Database (Denmark)

    Egsgaard, H.; Carlsen, L.; Øgaard Madsen, J.

    1994-01-01

    The protonated nitrosamide, NH3NO+, has been generated by chemical ionization mass spectrometry. Although a direct search for this species in ammonia flames has proved negative, fast proton transfer to major flame constituents is supported experimentally as well as by MO calculations....

  8. Proton Therapy

    Science.gov (United States)

    ... therapy is one of the most precise and advanced forms of radiation treatment available. How Proton Therapy is Delivered The patient is positioned on a table with a head frame or face mask covering the head. As the cyclotron smashes atoms, the protons released are directed toward ...

  9. SMALL VESICLES, BIG VEHICLES: EXOSOMES.

    Directory of Open Access Journals (Sweden)

    Saiz-Lopez P

    2016-09-01

    Full Text Available Exosomes are small membranous vesicles released by different cell types. Since their discovery, they have evolved from being considered simple vehicles for the liberation of cellular wastes, to become one of the most promising fields in the area of biomedical research, and more specifically in oncology, since the different malignant tumors release exosomes to all biological fluids, being involved in various functions of the neoplastic process. At present, it is possible to study these vesicles by minimally invasive techniques in patients, which approach us to obtain a more detailed diagnosis and prognosis, as well as to the discovery of new antitumoral therapies

  10. Vesicles and vesicle fusion: coarse-grained simulations

    DEFF Research Database (Denmark)

    Shillcock, Julian C.

    2010-01-01

    Biological cells are highly dynamic, and continually move material around their own volume and between their interior and exterior. Much of this transport encapsulates the material inside phospholipid vesicles that shuttle to and fro, fusing with, and budding from, other membranes. A feature of v...

  11. Pumps; Pumpen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, H. [Gesellschaft fuer Praktische Energiekunde e.V., Muenchen (Germany). Forschungsstelle fuer Energiewirtschaft; Hellriegel, E. [Gesellschaft fuer Praktische Energiekunde e.V., Muenchen (Germany). Forschungsstelle fuer Energiewirtschaft; Pfitzner, G. [Gesellschaft fuer Praktische Energiekunde e.V., Muenchen (Germany). Forschungsstelle fuer Energiewirtschaft

    1994-11-01

    The technical features of commercial pump types are described with regard to their technical, energy-related and economic parameters, and characteristic data are presented in the form of data sheets. This is to provide a basis for a comparative assessment of different technologies and technical variants. The chapter `System specifications` describes the various fields of application of pumps and the resulting specific requirements. The design and function of the different pump types are described in `Technical description`. `System and plant description dscribes the design and adaptation of pumps, i.e. the adaptation of the plant data to the system requirements. `Data compilation` provides a survey of the types and systematics of the compiled data as well as a decision aid for selecting the pumps best suited to the various applications. The `Data sheet` section describes the structure and handling of the data sheets as well as the data contained therein. The data sheets are contained in the apapendix of this report. The section `General analysis` compares typical technical, energy-related and economic characteristics of the different pump types. This is to enable a rough comparison of pump types and to facilitate decisions. The chapter `Example` illustrates the use of the data sheets by means of a selected example. (orig./GL) [Deutsch] Die vorliegende Arbeit hat zum Ziel, Technik seriengefertigter und marktgaengiger Pumpen in typisierter Form hinsichtlich ihrer technischen, energetischen und wirtschaftlichen Parameter zu beschreiben und ihre charakteristischen Kennwerte in Datenblaettern abzubilden. Damit wird ein grundlegendes Instrument fuer die vergleichende Beurteilung unterschiedlicher Techniken bzw. Technikvarianten hinsichtlich energetischer und wirtschaftlicher Kriterien geschaffen. Im Abschnitt `Systemanforderungen` erfolgt die Beschreibung der einzelnen Anwendungsbereiche fuer Pumpen mit den speziellen daraus resultierenden Anforderungen. Der Aufbau und

  12. Ca2+ Dependence of Synaptic Vesicle Endocytosis.

    Science.gov (United States)

    Leitz, Jeremy; Kavalali, Ege T

    2016-10-01

    Ca(2+)-dependent synaptic vesicle recycling is essential for structural homeostasis of synapses and maintenance of neurotransmission. Although, the executive role of intrasynaptic Ca(2+) transients in synaptic vesicle exocytosis is well established, identifying the exact role of Ca(2+) in endocytosis has been difficult. In some studies, Ca(2+) has been suggested as an essential trigger required to initiate synaptic vesicle retrieval, whereas others manipulating synaptic Ca(2+) concentrations reported a modulatory role for Ca(2+) leading to inhibition or acceleration of endocytosis. Molecular studies of synaptic vesicle endocytosis, on the other hand, have consistently focused on the roles of Ca(2+)-calmodulin dependent phosphatase calcineurin and synaptic vesicle protein synaptotagmin as potential Ca(2+) sensors for endocytosis. Most studies probing the role of Ca(2+) in endocytosis have relied on measurements of synaptic vesicle retrieval after strong stimulation. Strong stimulation paradigms elicit fusion and retrieval of multiple synaptic vesicles and therefore can be affected by several factors besides the kinetics and duration of Ca(2+) signals that include the number of exocytosed vesicles and accumulation of released neurotransmitters thus altering fusion and retrieval processes indirectly via retrograde signaling. Studies monitoring single synaptic vesicle endocytosis may help resolve this conundrum as in these settings the impact of Ca(2+) on synaptic fusion probability can be uncoupled from its putative role on synaptic vesicle retrieval. Future experiments using these single vesicle approaches will help dissect the specific role(s) of Ca(2+) and its sensors in synaptic vesicle endocytosis. © The Author(s) 2015.

  13. Extracellular vesicles in physiological and pathological conditions

    NARCIS (Netherlands)

    Yuana, Yuana; Sturk, Auguste; Nieuwland, Rienk

    2013-01-01

    Body fluids contain surprising numbers of cell-derived vesicles which are now thought to contribute to both physiology and pathology. Tools to improve the detection of vesicles are being developed and clinical applications using vesicles for diagnosis, prognosis, and therapy are under investigation.

  14. Membrane Trafficking and Vesicle Fusion

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 19; Issue 5. Membrane Trafficking and Vesicle Fusion: Post-Palade Era Researchers Win the Nobel Prize. Riddhi Atul Jani Subba Rao Gangi Setty. General Article Volume 19 Issue 5 May 2014 pp 421-445 ...

  15. Proton interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Morris, Christopher L [Los Alamos National Laboratory

    2008-01-01

    Energetic proton beams may provide an attractive alternative when compared to electromagnetic and neutron beams for active interrogation of nuclear threats because: they have large fission cross sections, long mean free paths and high penetration, and proton beams can be manipulated with magnetic optics. We have measured time-dependent cross sections for delayed neutrons and gamma-rays using the 800 MeV proton beam from the Los Alamos Neutron Science Center for a set of bare and shielded targets. The results show significant signals from both unshielded and shielded nuclear materials. Results will be presented.

  16. Heat pump

    OpenAIRE

    Klíma, Martin

    2010-01-01

    Bakalářská práce popisuje a charakterizuje tepelné čerpadlo. Obsahuje souhrn jednotlivých druhů tepelných čerpadel z hlediska získávání energie, princip jejich funkce a popis odlišností mezi jednotlivými druhy kompresorů, použití pracovní látky a její vývin do budoucna. Závěrem je zde uveden můj vlastní názor na tepelné čerpadlo, které bych preferoval. Bachelor thesis describes and characterizes the heat pump. Summarizes the various types of heat pumps in terms of energy production, princi...

  17. Inhibition of mTOR improves the impairment of acidification in autophagic vesicles caused by hepatic steatosis

    Energy Technology Data Exchange (ETDEWEB)

    Nakadera, Eisuke [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Yamashina, Shunhei, E-mail: syamashi@juntendo.ac.jp [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Izumi, Kousuke; Inami, Yoshihiro; Sato, Toshifumi; Fukushima, Hirofumi; Kon, Kazuyoshi; Ikejima, Kenichi [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Ueno, Takashi [Division of Proteomics and Biomolecular Science, Juntendo University, School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Watanabe, Sumio [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2016-01-22

    Recent investigations revealed that dysfunction of autophagy involved in the progression of chronic liver diseases such as alcoholic and nonalcoholic steatohepatitis and hepatocellular neoplasia. Previously, it was reported that hepatic steatosis disturbs autophagic proteolysis via suppression of both autophagic induction and lysosomal function. Here, we demonstrate that autophagic acidification was altered by a decrease in lysosomal proton pump vacuolar-ATPase (V-ATPase) in steatohepatitis. The number of autophagic vesicles was increased in hepatocytes from obese KKAy mice as compared to control. Similarly, autophagic membrane protein LC3-II and lysosomal protein LAMP-2 expression were enhanced in KKAy mice liver. Nevertheless, both phospho-mTOR and p62 expression were augmented in KKAy mice liver. More than 70% of autophagosomes were stained by LysoTracker Red (LTR) in hepatocytes from control mice; however, the percentage of acidic autolysosomes was decreased in hepatocytes from KKAy mice significantly (40.1 ± 3.48%). Both protein and RNA level of V-ATPase subunits ATP6v1a, ATP6v1b, ATP6v1d in isolated lysosomes were suppressed in KKAy mice as compared to control. Interestingly, incubation with mTOR inhibitor rapamycin increased in the rate of LTR-positive autolysosomes in hepatocytes from KKAy mice and suppressed p62 accumulation in the liver from KKAy mice which correlated to an increase in the V-ATPase subunits expression. These results indicate that down-regulation of V-ATPase due to hepatic steatosis causes autophagic dysfunction via disruption of lysosomal and autophagic acidification. Moreover, activation of mTOR plays a pivotal role on dysregulation of lysosomal and autophagic acidification by modulation of V-ATPase expression and could therefore be a useful therapeutic target to ameliorate dysfunction of autophagy in NAFLD. - Highlights: • Hepatic steatosis causes accumulation of autophagic vesicles in hepatocytes. • Hepatic steatosis disturbs

  18. The readily releasable pool of synaptic vesicles.

    Science.gov (United States)

    Kaeser, Pascal S; Regehr, Wade G

    2017-04-01

    Each presynaptic bouton is densely packed with many vesicles, only a small fraction of which are available for immediate release. These vesicles constitute the readily releasable pool (RRP). The RRP size, and the probability of release of each vesicle within the RRP, together determine synaptic strength. Here, we discuss complications and recent advances in determining the size of the physiologically relevant RRP. We consider molecular mechanisms to generate and regulate the RRP, and discuss the relationship between vesicle docking and the RRP. We conclude that many RRP vesicles are docked, that some docked vesicles may not be part of the RRP, and that undocked vesicles can contribute to the RRP by rapid recruitment to unoccupied, molecularly activated ready-to-release sites. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Light-induced DELTApH and DELTApsi in halobacterial vesicles related to sodium transport

    Energy Technology Data Exchange (ETDEWEB)

    Kamo, N.; Racanclli, T.; Packer, L.

    1986-01-01

    Membranes of Halobacterium halobium contain two retinoproteins, baceteriorhodopsin (BR/sub 568nm/) and halorhodopsin (HR/sub 588nm/). We have investigated the light- and sodium-dependent activities in vesicles from the HR containing R/sub 1/mR strain, and the BR + HR containing S/sub 9/ strain to study energy conversion and ion flow mechanisms. Simultaneous ..delta..pH and ..delta..psi measurements have been made with electrodes. In R/sub 1/mR vesicles, -..delta..psi and H/sup +/ uptake occurs in NaCl but not in KCl medium. In S/sub 9/ vesicles, net H/sup +/ extrusion is reduced at high light intensity in NaCl but not KCl medium. Such results indicate Na/sup +//H/sup +/ exchange in vesicles from both strains. As S/sub 9/ contains BR + HR, it is unclear whether the Na/sup +/ extrusion is due to a Na/sup +//H/sup +/ antiporter and/or HR which has been proposed to be a light driven Na/sup +/ pump. To evaluate these concepts for Na/sup +/ transport, the light intensity dependence and action of several membrane transport active agents have been compared. Digitoxin, electro-neutral exchangers (triphenyltin and monensin), and phloretin yielded similar results for HR (R/sub 1/mR) and HR + BR (S/sub 9/) vesicles. Moreover treatment of vesicles with carboxyl reacting reagents inhibited Na/sup +/ dependent activity in both types of vesicles. Thus, common mechanisms of Na/sup +/ transport are indicated in S/sub 9/ and R/sub 1/mR vesicles. 22 refs., 9 figs., 1 tab.

  20. Phospholipid Vesicles in Materials Science

    Energy Technology Data Exchange (ETDEWEB)

    Granick, Steve [Univ. of Illinois, Champaign, IL (United States)

    2016-05-11

    The objective of this research was to develop the science basis needed to deploy phospholipid vesicles as functional materials in energy contexts. Specifically, we sought to: (1) Develop an integrated molecular-level understanding of what determines their dynamical shape, spatial organization, and responsiveness to complex, time-varying environments; and (2) Develop understanding of their active transportation in crowded environments, which our preliminary measurements in cells suggest may hold design principles for targeting improved energy efficiency in new materials systems. The methods to do this largely involved fluorescence imaging and other spectroscopy involving single particles, vesicles, particles, DNA, and endosomes. An unexpected importance outcome was a new method to image light-emitting diodes during actual operation using super-resolution spectroscopy.

  1. Dynamics of endocytic vesicle creation.

    Science.gov (United States)

    Perrais, David; Merrifield, Christien J

    2005-11-01

    Clathrin-mediated endocytosis is the main path for receptor internalization in metazoans and is essential for controlling cell integrity and signaling. It is driven by a large array of protein and lipid interactions that have been deciphered mainly by biochemical and genetic means. To place these interactions into context, and ultimately build a fully operative model of endocytosis at the molecular level, it is necessary to know the kinetic details of the role of each protein in this process. In this review, we describe the recent efforts made, by using live cell imaging, to define clear steps in the formation of endocytic vesicles and to observe the recruitment of key proteins during membrane invagination, the scission of a newly formed vesicle, and its movement away from the plasma membrane.

  2. Extracellular vesicles and blood diseases.

    Science.gov (United States)

    Nomura, Shosaku

    2017-04-01

    Extracellular vesicles (EVs) are small membrane vesicles released from many different cell types by the exocytic budding of the plasma membrane in response to cellular activation or apoptosis. EVs disseminate various bioactive effectors originating from the parent cells and transfer functional RNA and protein between cells, enabling them to alter vascular function and induce biological responses involved in vascular homeostasis. Although most EVs in human blood originate from platelets, EVs are also released from leukocytes, erythrocytes, endothelial cells, smooth muscle cells, and cancer cells. EVs were initially thought to be small particles with procoagulant activity; however, they can also evoke cellular responses in the immediate microenvironments and transport microRNAs (miRNA) into target cells. In this review, we summarize the recent literature relevant to EVs, including a growing list of clinical disorders that are associated with elevated EV levels. These studies suggest that EVs play roles in various blood diseases.

  3. Proton Gradients as a Key Physical Factor in the Evolution of the Forced Transport Mechanism Across the Lipid Membrane

    Science.gov (United States)

    Strbak, Oliver; Kanuchova, Zuzana; Krafcik, Andrej

    2016-11-01

    A critical phase in the transition from prebiotic chemistry to biological evolution was apparently an asymmetric ion flow across the lipid membrane. Due to imbalance in the ion flow, the early lipid vesicles could selectively take the necessary molecules from the environment, and release the side-products from the vesicle. Natural proton gradients played a definitively crucial role in this process, since they remain the basis of energy transfer in the present-day cells. On the basis of this supposition, and the premise of the early vesicle membrane's impermeability to protons, we have shown that the emergence of the proton gradient in the lipid vesicle could be a key physical factor in the evolution of the forced transport mechanism (pore formation and active transport) across the lipid bilayer. This driven flow of protons across the membrane is the result of the electrochemical proton gradient and osmotic pressures on the integrity of the lipid vesicle. At a critical number of new lipid molecules incorporated into the vesicle, the energies associated with the creation of the proton gradient exceed the bending stiffness of the lipid membrane, and overlap the free energy of the lipid bilayer pore formation.

  4. Proton Gradients as a Key Physical Factor in the Evolution of the Forced Transport Mechanism Across the Lipid Membrane.

    Science.gov (United States)

    Strbak, Oliver; Kanuchova, Zuzana; Krafcik, Andrej

    2016-11-01

    A critical phase in the transition from prebiotic chemistry to biological evolution was apparently an asymmetric ion flow across the lipid membrane. Due to imbalance in the ion flow, the early lipid vesicles could selectively take the necessary molecules from the environment, and release the side-products from the vesicle. Natural proton gradients played a definitively crucial role in this process, since they remain the basis of energy transfer in the present-day cells. On the basis of this supposition, and the premise of the early vesicle membrane's impermeability to protons, we have shown that the emergence of the proton gradient in the lipid vesicle could be a key physical factor in the evolution of the forced transport mechanism (pore formation and active transport) across the lipid bilayer. This driven flow of protons across the membrane is the result of the electrochemical proton gradient and osmotic pressures on the integrity of the lipid vesicle. At a critical number of new lipid molecules incorporated into the vesicle, the energies associated with the creation of the proton gradient exceed the bending stiffness of the lipid membrane, and overlap the free energy of the lipid bilayer pore formation.

  5. Vibrational Förster transfer to hydrated protons

    NARCIS (Netherlands)

    Timmer, R.L.A.; Tielrooij, K.J.; Bakker, H.J.

    2010-01-01

    We have studied the influence of excess protons on the vibrational energy relaxation of the O-H and O-D stretching modes in water using femtosecond pump-probe spectroscopy. Without excess protons, we observe exponential decays with time constants of 1.7 and 4.3 ps for the bulk and anion bound O-D

  6. Unraveling the Mechanism of a Reversible Photoactivated Molecular Proton Crane

    NARCIS (Netherlands)

    van der Loop, T.H.; Ruesink, F.; Amirjalayer, S.; Sanders, H. J.; Buma, W.J.; Woutersen, S.

    2014-01-01

    Structural dynamics of the photoactivated mol. proton crane 7-​hydroxy-​8-​(morpholinomethyl)​quinoline has been studied using femtosecond UV-​pump IR-​probe spectroscopy. Upon electronic excitation, a proton is transferred from the hydroxy to the amine group located on the rotatable morpholino side

  7. Immunotherapeutic potential of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Bin eZhang

    2014-10-01

    Full Text Available Extracellular vesicles or EVs is a term that encompasses all classes of secreted lipid membrane vesicles. Despite being scientific novelties, EVs are gaining importance as a mediator of important physiological and pathological intercellular activities possibly through the transfer of their cargo of protein and RNA between cells. In particular, exosomes the currently best characterized EVs have been notable for their in vitro and in vivo immunomodulatory activities. Exosomes are nanometer-sized endosome-derived vesicles secreted by many cell types and their immunomodulatory potential is independent of their cell source. Besides immune cells such as dendritic cells, macrophages and T cells, cancer and stem cells also secrete immunologically active exosomes that could influence both physiological and pathological processes. The immunological activities of exosomes affect both innate and adaptive immunity and include antigen presentation, T cell activation, T cell polarisation to Tregs, immune suppression and anti-inflammation. As such, exosomes carry much immunotherapeutic potential as a therapeutic agent and a therapeutic target.

  8. The light-driven sodium ion pump: A new player in rhodopsin research.

    Science.gov (United States)

    Kato, Hideaki E; Inoue, Keiichi; Kandori, Hideki; Nureki, Osamu

    2016-12-01

    Rhodopsins are one of the most studied photoreceptor protein families, and ion-translocating rhodopsins, both pumps and channels, have recently attracted broad attention because of the development of optogenetics. Recently, a new functional class of ion-pumping rhodopsins, an outward Na(+) pump, was discovered, and following structural and functional studies enable us to compare three functionally different ion-pumping rhodopsins: outward proton pump, inward Cl(-) pump, and outward Na(+) pump. Here, we review the current knowledge on structure-function relationships in these three light-driven pumps, mainly focusing on Na(+) pumps. A structural and functional comparison reveals both unique and conserved features of these ion pumps, and enhances our understanding about how the structurally similar microbial rhodopsins acquired such diverse functions. We also discuss some unresolved questions and future perspectives in research of ion-pumping rhodopsins, including optogenetics application and engineering of novel rhodopsins. © 2016 The Authors. BioEssays Published by WILEY Periodicals, Inc.

  9. Proton transfer in ba(3) cytochrome c oxidase from Thermus thermophilus.

    Science.gov (United States)

    von Ballmoos, Christoph; Adelroth, Pia; Gennis, Robert B; Brzezinski, Peter

    2012-04-01

    The respiratory heme-copper oxidases catalyze reduction of O(2) to H(2)O, linking this process to transmembrane proton pumping. These oxidases have been classified according to the architecture, location and number of proton pathways. Most structural and functional studies to date have been performed on the A-class oxidases, which includes those that are found in the inner mitochondrial membrane and bacteria such as Rhodobacter sphaeroides and Paracoccus denitrificans (aa(3)-type oxidases in these bacteria). These oxidases pump protons with a stoichiometry of one proton per electron transferred to the catalytic site. The bacterial A-class oxidases use two proton pathways (denoted by letters D and K, respectively), for the transfer of protons to the catalytic site, and protons that are pumped across the membrane. The B-type oxidases such as, for example, the ba(3) oxidase from Thermus thermophilus, pump protons with a lower stoichiometry of 0.5 H(+)/electron and use only one proton pathway for the transfer of all protons. This pathway overlaps in space with the K pathway in the A class oxidases without showing any sequence homology though. Here, we review the functional properties of the A- and the B-class ba(3) oxidases with a focus on mechanisms of proton transfer and pumping. Copyright © 2012 Elsevier B.V. All rights reserved.

  10. Proton-transport mechanisms in cytochrome c oxidase revealed by studies of kinetic isotope effects

    Science.gov (United States)

    Johansson, Ann-Louise; Chakrabarty, Suman; Siöberg, Catrine Berthold; Högbom, Martin; Warshel, Arieh; Brzezinski, Peter

    2011-01-01

    Cytochrome c oxidase (CytcO) is a membrane-bound enzyme, which catalyzes the reduction of di-oxygen to water and uses a major part of the free energy released in this reaction to pump protons across the membrane. In the Rhodobacter sphaeroides aa3 CytcO all protons that are pumped across the membrane, as well as one half of the protons that are used for O2 reduction, are transferred through one specific intraprotein proton pathway, which holds a highly conserved Glu286 residue. Key questions that need to be addressed in order to understand the function of CytcO at a molecular level are related to the timing of proton transfers from Glu286 to a “pump site” and the catalytic site, respectively. Here, we have investigated the temperature dependencies of the H/D kinetic-isotope effects of intramolecular proton-transfer reactions in the wild-type CytcO as well as in two structural CytcO variants, one in which proton uptake from solution is delayed and one in which proton pumping is uncoupled from O2 reduction. These processes were studied for two specific reaction steps linked to transmembrane proton pumping, one that involves only proton transfer (peroxy–ferryl, P→F, transition) and one in which the same sequence of proton transfers is also linked to electron transfer to the catalytic site (ferryl–oxidized, F→O, transition). An analysis of these reactions in the framework of theory indicates that that the simpler, P→F reaction is rate-limited by proton transfer from Glu286 to the catalytic site. When the same proton-transfer events are also linked to electron transfer to the catalytic site (F→O), the proton-transfer reactions are gated by a protein structural change, which presumably ensures that the proton-pumping stoichiometry is maintained also in the presence of a transmembrane electrochemical gradient. PMID:21463601

  11. Pump characteristics and applications

    CERN Document Server

    Volk, Michael

    2013-01-01

    Providing a wealth of information on pumps and pump systems, Pump Characteristics and Applications, Third Edition details how pump equipment is selected, sized, operated, maintained, and repaired. The book identifies the key components of pumps and pump accessories, introduces the basics of pump and system hydraulics as well as more advanced hydraulic topics, and details various pump types, as well as special materials on seals, motors, variable frequency drives, and other pump-related subjects. It uses example problems throughout the text, reinforcing the practical application of the formulae

  12. Synaptic vesicle proteins and active zone plasticity

    Directory of Open Access Journals (Sweden)

    Robert J Kittel

    2016-04-01

    Full Text Available Neurotransmitter is released from synaptic vesicles at the highly specialized presynaptic active zone. The complex molecular architecture of active zones mediates the speed, precision and plasticity of synaptic transmission. Importantly, structural and functional properties of active zones vary significantly, even for a given connection. Thus, there appear to be distinct active zone states, which fundamentally influence neuronal communication by controlling the positioning and release of synaptic vesicles. Vice versa, recent evidence has revealed that synaptic vesicle components also modulate organizational states of the active zone.The protein-rich cytomatrix at the active zone (CAZ provides a structural platform for molecular interactions guiding vesicle exocytosis. Studies in Drosophila have now demonstrated that the vesicle proteins Synaptotagmin-1 (Syt1 and Rab3 also regulate glutamate release by shaping differentiation of the CAZ ultrastructure. We review these unexpected findings and discuss mechanistic interpretations of the reciprocal relationship between synaptic vesicles and active zone states, which has heretofore received little attention.

  13. Single-vesicle imaging reveals different transport mechanisms between glutamatergic and GABAergic vesicles

    NARCIS (Netherlands)

    Farsi, Z.; Preobraschenski, J.; Bogaart, G. van den; Riedel, D.; Jahn, R.; Woehler, A.

    2016-01-01

    Synaptic transmission is mediated by the release of neurotransmitters, which involves exo-endocytotic cycling of synaptic vesicles. To maintain synaptic function, synaptic vesicles are refilled with thousands of neurotransmitter molecules within seconds after endocytosis, using the energy provided

  14. Extracellular Vesicles: Evolving Contributors in Autoimmunity

    OpenAIRE

    Katsiougiannis, Stergios

    2015-01-01

    Extracellular vesicles, including microvesicles, exosomes and apoptotic bodies are recognized as carriers of pathogen-associated molecules with direct involvement in immune signaling and inflammation. Those observations have enforced the way these membranous vesicles are being considered as promising immunotherapeutic targets. In this review, we discuss the emerging roles of extracellular vesicles in autoimmunity and highlights their potential use as disease biomarkers as well as targets for ...

  15. Exosomes: secreted vesicles and intercellular communications

    OpenAIRE

    Théry, Clotilde

    2011-01-01

    Exosomes are small membrane vesicles of endocytic origin secreted by most cell types, and are thought to play important roles in intercellular communications. Although exosomes were originally described in 1983, interest in these vesicles has really increased dramatically in the last 3 years, after the finding that they contain mRNA and microRNA. This discovery sparked renewed interest for the general field of membrane vesicles involved in intercellular communications, and research on these s...

  16. Types of Breast Pumps

    Science.gov (United States)

    ... Health and Consumer Devices Consumer Products Breast Pumps Types of Breast Pumps Share Tweet Linkedin Pin it ... a nipple and used for feeding a baby. Types of Breast Pumps There are three basic types ...

  17. Trafficking of astrocytic vesicles in hippocampal slices

    Energy Technology Data Exchange (ETDEWEB)

    Potokar, Maja; Kreft, Marko [Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana (Slovenia); Celica Biomedical Center, Technology Park 24, 1000 Ljubljana (Slovenia); Lee, So-Young; Takano, Hajime; Haydon, Philip G. [Department of Neuroscience, Room 215, Stemmler Hall, University of Pennsylvania, School of Medicine, Philadelphia, PA 19104 (United States); Zorec, Robert, E-mail: Robert.Zorec@mf.uni-lj.si [Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloska 4, 1000 Ljubljana (Slovenia); Celica Biomedical Center, Technology Park 24, 1000 Ljubljana (Slovenia)

    2009-12-25

    The increasingly appreciated role of astrocytes in neurophysiology dictates a thorough understanding of the mechanisms underlying the communication between astrocytes and neurons. In particular, the uptake and release of signaling substances into/from astrocytes is considered as crucial. The release of different gliotransmitters involves regulated exocytosis, consisting of the fusion between the vesicle and the plasma membranes. After fusion with the plasma membrane vesicles may be retrieved into the cytoplasm and may continue to recycle. To study the mobility implicated in the retrieval of secretory vesicles, these structures have been previously efficiently and specifically labeled in cultured astrocytes, by exposing live cells to primary and secondary antibodies. Since the vesicle labeling and the vesicle mobility properties may be an artifact of cell culture conditions, we here asked whether the retrieving exocytotic vesicles can be labeled in brain tissue slices and whether their mobility differs to that observed in cell cultures. We labeled astrocytic vesicles and recorded their mobility with two-photon microscopy in hippocampal slices from transgenic mice with fluorescently tagged astrocytes (GFP mice) and in wild-type mice with astrocytes labeled by Fluo4 fluorescence indicator. Glutamatergic vesicles and peptidergic granules were labeled by the anti-vesicular glutamate transporter 1 (vGlut1) and anti-atrial natriuretic peptide (ANP) antibodies, respectively. We report that the vesicle mobility parameters (velocity, maximal displacement and track length) recorded in astrocytes from tissue slices are similar to those reported previously in cultured astrocytes.

  18. Reversibly formed bilayer vesicles: Energetics and polydispersity

    DEFF Research Database (Denmark)

    Bergstöm, M.

    1997-01-01

    orders of magnitude larger than where the local free energy minima of the equilibrium vesicle actually occur. Moreover, according to our analysis, the relative width of a vesicle size distribution, sigma(R)/R-max, is generally at full equilibrium equal to 0.283, independently of the energetic vesicle....... and a statistical-mechanical factor that accounts for the fluctuations in composition, chain packing density and shape. We demonstrate that the free energy required to form a spherical vesicle is made up of two main contributions: the (size-independent) work of bending the constituent monolayers and the work...

  19. Extracellular vesicles in cardiovascular homeostasis and disease.

    Science.gov (United States)

    Hutcheson, Joshua D; Aikawa, Elena

    2018-02-19

    Extracellular vesicles have emerged as one of the most important means through which cells interact with each other and the extracellular environment, but extracellular vesicle research remains challenging due to their small size, limited amount of material required for traditional molecular biology assays and inconsistency in the methods of their isolation. The advent of new technologies and standards in the field, however, have led to increased mechanistic insight into extracellular vesicle function. Herein, the latest studies on the role of extracellular vesicles in cardiovascular physiology and disease are discussed. Extracellular vesicles help control cardiovascular homeostasis and remodelling by mediating communication between cells and directing alterations in the extracellular matrix to respond to changes in the environment. The message carried from the parent cell to extracellular space can be intended for both local (within the same tissue) and distal (downstream of blood flow) targets. Pathological cargo loaded within extracellular vesicles could further result in various diseases. On the contrary, new studies indicate that injection of extracellular vesicles obtained from cultured cells into diseased tissues can promote restoration of normal tissue function. Extracellular vesicles are an integral part of cell and tissue function, and harnessing the properties inherent to extracellular vesicles may provide a therapeutic strategy to promote tissue regeneration.

  20. Extracellular vesicles in cartilage homeostasis and osteoarthritis.

    Science.gov (United States)

    Miyaki, Shigeru; Lotz, Martin K

    2018-01-01

    Extracellular vesicles carry bioactive molecules that can be transferred between cells and tissues. The purpose of this review is to describe how extracellular vesicles regulate functions of cells in cartilage and other joint tissues. The potential application of extracellular vesicles in the treatment of osteoarthritis and as biomarkers will also be discussed. Extracellular vesicles are found in synovial fluid, in articular cartilage and in the supernatants of synoviocytes and chondrocytes. Extracellular vesicles in cartilage have been proposed to be involved in cross talk between cells in joint tissues and to affect extracellular matrix turnover and inflammation. Extracellular vesicles from arthritic joints can promote abnormal gene expression and changes in cartilage extracellular matrix, including abnormal mineralization. Promising results were obtained in the therapeutic application of mesenchymal stem cell-derived extracellular vesicles for cartilage repair and experimental osteoarthritis. Extracellular vesicles have emerged as vehicles for the exchange of bioactive signaling molecules within cartilage and between joint tissues to promote joint homeostasis and arthritis pathogenesis. As the molecular content of extracellular vesicles can be customized, they offer utility in therapeutic applications.

  1. Supramolecular Vesicles Coassembled from Disulfide-Linked Benzimidazolium Amphiphiles and Carboxylate-Substituted Pillar[6]arenes that Are Responsive to Five Stimuli.

    Science.gov (United States)

    Jiang, Long; Huang, Xuan; Chen, Dong; Yan, Hua; Li, Xueyuan; Du, Xuezhong

    2017-03-01

    Novel supramolecular vesicles based on host-guest systems were coassembled from carboxylate-substituted pillar[6]arene (CPA[6]) and disulfide-linked benzimidazolium amphiphiles, and the microstructures of the CPA-based supramolecular vesicles were clearly elaborated. The supramolecular vesicles showed controlled drug release in response to five stimuli, with glutathione, pH, CO2 , Zn2+ ions, and hexanediamine, leading to cleavage of the disulfide bonds, protonation of the carboxylate groups, metal chelation, and competitive binding. This is the first case of a smart pillararene-based supramolecular vesicle being integrated with five stimuli-responsive functions to meet the diverse requirements of controlled drug release. Importantly, each of the five stimuli is closely related to microenvironments of tumors and diseases of the human body. The smart stimuli-responsive supramolecular vesicles have promising applications in drug therapy of tumors and relevant diseases. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Heat pump technology

    CERN Document Server

    Von Cube, Hans Ludwig; Goodall, E G A

    2013-01-01

    Heat Pump Technology discusses the history, underlying concepts, usage, and advancements in the use of heat pumps. The book covers topics such as the applications and types of heat pumps; thermodynamic principles involved in heat pumps such as internal energy, enthalpy, and exergy; and natural heat sources and energy storage. Also discussed are topics such as the importance of the heat pump in the energy industry; heat pump designs and systems; the development of heat pumps over time; and examples of practical everyday uses of heat pumps. The text is recommended for those who would like to kno

  3. Extracellular Vesicles in Cardiovascular Theranostics.

    Science.gov (United States)

    Bei, Yihua; Das, Saumya; Rodosthenous, Rodosthenis S; Holvoet, Paul; Vanhaverbeke, Maarten; Monteiro, Marta Chagas; Monteiro, Valter Vinicius Silva; Radosinska, Jana; Bartekova, Monika; Jansen, Felix; Li, Qian; Rajasingh, Johnson; Xiao, Junjie

    2017-01-01

    Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells. Increasing evidence has shown the important regulatory effects of EVs in cardiovascular diseases (CVDs). EVs secreted by cardiomyocytes, endothelial cells, fibroblasts, and stem cells play essential roles in pathophysiological processes such as cardiac hypertrophy, cardiomyocyte survival and apoptosis, cardiac fibrosis, and angiogenesis in relation to CVDs. In this review, we will first outline the current knowledge about the physical characteristics, biological contents, and isolation methods of EVs. We will then focus on the functional roles of cardiovascular EVs and their pathophysiological effects in CVDs, as well as summarize the potential of EVs as therapeutic agents and biomarkers for CVDs. Finally, we will discuss the specific application of EVs as a novel drug delivery system and the utility of EVs in the field of regenerative medicine.

  4. Illuminating the physiology of extracellular vesicles

    OpenAIRE

    Choi, Hongyoon; Lee, Dong Soo

    2016-01-01

    Extracellular vesicles play a crucial role in intercellular communication by transmitting biological materials from donor cells to recipient cells. They have pathophysiologic roles in cancer metastasis, neurodegenerative diseases, and inflammation. Extracellular vesicles also show promise as emerging therapeutics, with understanding of their physiology including targeting, distribution, and clearance therefore becoming an important issue. Here, we review recent advances in methods for trackin...

  5. Amyloglucosidase enzymatic reactivity inside lipid vesicles

    Directory of Open Access Journals (Sweden)

    Kim Jin-Woo

    2007-10-01

    Full Text Available Abstract Efficient functioning of enzymes inside liposomes would open new avenues for applications in biocatalysis and bioanalytical tools. In this study, the entrapment of amyloglucosidase (AMG (EC 3.2.1.3 from Aspergillus niger into dipalmitoylphosphatidylcholine (DPPC multilamellar vesicles (MLVs and large unilamellar vesicles (LUVs was investigated. Negative-stain, freeze-fracture, and cryo-transmission electron microscopy images verified vesicle formation in the presence of AMG. Vesicles with entrapped AMG were isolated from the solution by centrifugation, and vesicle lamellarity was identified using fluorescence laser confocal microscopy. The kinetics of starch hydrolysis by AMG was modeled for two different systems, free enzyme in aqueous solution and entrapped enzyme within vesicles in aqueous suspension. For the free enzyme system, intrinsic kinetics were described by a Michaelis-Menten kinetic model with product inhibition. The kinetic constants, Vmax and Km, were determined by initial velocity measurements, and Ki was obtained by fitting the model to experimental data of glucose concentration-time curves. Predicted concentration-time curves using these kinetic constants were in good agreement with experimental measurements. In the case of the vesicles, the time-dependence of product (glucose formation was experimentally determined and simulated by considering the kinetic behavior of the enzyme and the permeation of substrate into the vesicle. Experimental results demonstrated that entrapped enzymes were much more stable than free enyzme. The entrapped enzyme could be recycled with retention of 60% activity after 3 cycles. These methodologies can be useful in evaluating other liposomal catalysis operations.

  6. Extracellular vesicles in coronary artery disease.

    Science.gov (United States)

    Boulanger, Chantal M; Loyer, Xavier; Rautou, Pierre-Emmanuel; Amabile, Nicolas

    2017-05-01

    Membrane vesicles released in the extracellular space are composed of a lipid bilayer enclosing soluble cytosolic material and nuclear components. Extracellular vesicles include apoptotic bodies, exosomes, and microvesicles (also known previously as microparticles). Originating from different subcellular compartments, the role of extracellular vesicles as regulators of transfer of biological information, acting locally and remotely, is now acknowledged. Circulating vesicles released from platelets, erythrocytes, leukocytes, and endothelial cells contain potential valuable biological information for biomarker discovery in primary and secondary prevention of coronary artery disease. Extracellular vesicles also accumulate in human atherosclerotic plaques, where they affect major biological pathways, including inflammation, proliferation, thrombosis, calcification, and vasoactive responses. Extracellular vesicles also recapitulate the beneficial effect of stem cells to treat cardiac consequences of acute myocardial infarction, and now emerge as an attractive alternative to cell therapy, opening new avenues to vectorize biological information to target tissues. Although interest in microvesicles in the cardiovascular field emerged about 2 decades ago, that for extracellular vesicles, in particular exosomes, started to unfold a decade ago, opening new research and therapeutic avenues. This Review summarizes current knowledge on the role of extracellular vesicles in coronary artery disease, and their emerging potential as biomarkers and therapeutic agents.

  7. Detection of extracellular vesicles: size does matter

    NARCIS (Netherlands)

    van der Pol, E.

    2015-01-01

    Cells release small sacks filled with fluid, which are called "extracellular vesicles". The diameter of extracellular vesicles (EV) typically ranges from 30 nm to 1 µm. Because cells release EV into their environment, our body fluids contain numerous EV. Cells release EV to remove waste and to

  8. Synaptic vesicle distribution by conveyor belt.

    Science.gov (United States)

    Moughamian, Armen J; Holzbaur, Erika L F

    2012-03-02

    The equal distribution of synaptic vesicles among synapses along the axon is critical for robust neurotransmission. Wong et al. show that the continuous circulation of synaptic vesicles throughout the axon driven by molecular motors ultimately yields this even distribution. Copyright © 2012 Elsevier Inc. All rights reserved.

  9. Urinary extracellular vesicles: biomarkers and beyond

    NARCIS (Netherlands)

    M. Salih (Mahdi)

    2017-01-01

    markdownabstractExtracellular vesicles have been isolated in various body fluids including urine. The cargo of urinary extracellular vesicles (uEVs) is composed of proteins and nucleic acids reflecting the physiological and possibly the pathophysiological state of cells lining the nephron. Because

  10. Fusion Competent Synaptic Vesicles Persist upon Active Zone Disruption and Loss of Vesicle Docking.

    Science.gov (United States)

    Wang, Shan Shan H; Held, Richard G; Wong, Man Yan; Liu, Changliang; Karakhanyan, Aziz; Kaeser, Pascal S

    2016-08-17

    In a nerve terminal, synaptic vesicle docking and release are restricted to an active zone. The active zone is a protein scaffold that is attached to the presynaptic plasma membrane and opposed to postsynaptic receptors. Here, we generated conditional knockout mice removing the active zone proteins RIM and ELKS, which additionally led to loss of Munc13, Bassoon, Piccolo, and RIM-BP, indicating disassembly of the active zone. We observed a near-complete lack of synaptic vesicle docking and a strong reduction in vesicular release probability and the speed of exocytosis, but total vesicle numbers, SNARE protein levels, and postsynaptic densities remained unaffected. Despite loss of the priming proteins Munc13 and RIM and of docked vesicles, a pool of releasable vesicles remained. Thus, the active zone is necessary for synaptic vesicle docking and to enhance release probability, but releasable vesicles can be localized distant from the presynaptic plasma membrane. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Alternative methods for characterization of extracellular vesicles

    Directory of Open Access Journals (Sweden)

    Fatemeh eMomen-Heravi

    2012-09-01

    Full Text Available Extracellular vesicles are nano-sized vesicles released by all cells in vitro as well as in vivo. Their role has been implicated mainly in cell-cell communication, but also in disease biomarkers and more recently in gene delivery. They represent a snapshot of the cell status at the moment of release and carry bioreactive macromolecules such as nucleic acids, proteins and lipids. A major limitation in this emerging new field is the availability/awareness of techniques to isolate and properly characterize Extracellular vesicles. The lack of gold standards makes comparing different studies very difficult and may potentially hinder some Extracellular vesicles -specific evidence. Characterization of Extracellular vesicles has also recently seen many advances with the use of Nanoparticle Tracking Analysis (NTA, flow cytometry, cryo-EM instruments and proteomic technologies. In this review, we discuss the latest developments in translational technologies involving characterization methods including the facts in their support and the challenges they face.

  12. Extracellular vesicles: new players in cardiovascular diseases.

    Science.gov (United States)

    Gaceb, Abderahim; Martinez, Maria Carmen; Andriantsitohaina, Ramaroson

    2014-05-01

    Extracellular vesicles, particles released by all cell types, represent a new way to convey information between cells such as proteins, second messengers, and genetic information to modify the phenotype and function of the target cells. Recent data suggest that extracellular vesicles play a crucial role in both physiology and pathology, including coagulation, angiogenesis, cell survival, modulation of the immune response, and inflammation. Thus extracellular vesicles participate in the processes of cardiovascular diseases from atherosclerosis, myocardial infarction to heart failure. Consequently, extracellular vesicles can potentially be exploited for therapy, prognosis, and biomarkers for health and disease. This review focuses on the role of extracellular vesicles in the development of cardiovascular diseases, as well as the deleterious and beneficial effects that they may provide in vascular cells and myocardium. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. [Transvesical Removal of Seminal Vesicle Cystadenoma].

    Science.gov (United States)

    Takayasu, Kenta; Harada, Jiro; Kawa, Gen; Ota, Syuichi; Sakurai, Takanori

    2015-07-01

    Primary tumors of the seminal vesicles are extremely rare. There have been 25 reports of this tumor from overseas and most cases are cystadenoma. We report a case of seminal vesicle cystadenoma in a 70-year-old man who presented with lower abdominal pain and urinary frequency. A digital rectal examination detected a projecting and hard mass in the right side of the prostate. Magnetic resonance imaging (MRI) showed a 15 cm multiple cystic mass continuous with the right seminal vesicle. A transrectal needle biopsy revealed benign tissue. The tumor was resected using an open transvesical approach that enabled full exposure of the seminal vesicle without damaging the nerves and blood supply of the bladder. Pathology was consistent with a benign seminal vesicle cystadenoma. We describe the natural history, pathology,and surgical approach in this case.

  14. Pushing synaptic vesicles over the RIM.

    Science.gov (United States)

    Kaeser, Pascal S

    2011-05-01

    In a presynaptic nerve terminal, neurotransmitter release is largely restricted to specialized sites called active zones. Active zones consist of a complex protein network, and they organize fusion of synaptic vesicles with the presynaptic plasma membrane in response to action potentials. Rab3-interacting molecules (RIMs) are central components of active zones. In a recent series of experiments, we have systematically dissected the molecular mechanisms by which RIMs operate in synaptic vesicle release. We found that RIMs execute two critical functions of active zones by virtue of independent protein domains. They tether presyanptic Ca(2+) channels to the active zone, and they activate priming of synaptic vesicles by monomerizing homodimeric, constitutively inactive Munc13. These data indicate that RIMs orchestrate synaptic vesicle release into a coherent process. In conjunction with previous studies, they suggest that RIMs form a molecular platform on which plasticity of synaptic vesicle release can operate.

  15. Apoptotic Bodies: Selective Detection in Extracellular Vesicles.

    Science.gov (United States)

    Hauser, Paul; Wang, Sha; Didenko, Vladimir V

    2017-01-01

    Normal and dying cells release various types of membrane-bound vesicles including microvesicles, exosomes, and apoptotic bodies. These vesicles play important roles in intercellular communication and signal transduction. However, their diverse forms and subtypes fluctuate in size and other properties. In result current purification approaches do not fully discriminate between different categories of extracellular vesicles. Here, we present a fluorescence technique that specifically identifies apoptotic bodies in preparations of microvesicles, exosomes, and other extracellular vesicles.The approach exclusively labels the vesicles that contain DNA with 5'PO 4 blunt-ended DNA breaks, such as those produced by the apoptotic CAD nuclease during apoptotic DNA degradation. The technique can be useful in studies of apoptosis involving microvesicles and exosomes.

  16. Multiple pump housing

    Science.gov (United States)

    Donoho, II, Michael R.; Elliott; Christopher M.

    2010-03-23

    A fluid delivery system includes a first pump having a first drive assembly, a second pump having a second drive assembly, and a pump housing. At least a portion of each of the first and second pumps are located in the housing.

  17. Monosaccharide transport in protein-depleted vesicles from erythrocyte membranes

    National Research Council Canada - National Science Library

    M A Zoccoli; G E Lienhard

    1977-01-01

    .... Based on comparisons between erythrocytes and vesicles with regard to specificity, temparture dependence, and effects of inhibitors, we conclude that sorbose uptake into the vesicles occurs by way...

  18. Centrifugal pump handbook

    CERN Document Server

    Pumps, Sulzer

    2010-01-01

    This long-awaited new edition is the complete reference for engineers and designers working on pump design and development or using centrifugal pumps in the field. This authoritative guide has been developed with access to the technical expertise of the leading centrifugal pump developer, Sulzer Pumps. In addition to providing the most comprehensive centrifugal pump theory and design reference with detailed material on cavitation, erosion, selection of materials, rotor vibration behavior and forces acting on pumps, the handbook also covers key pumping applications topics and operational

  19. Proton scaling

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, Gregory H [Los Alamos National Laboratory

    2009-01-01

    This note presents analytic estimates of the performance of proton beams in remote surveillance for nuclear materials. The analysis partitions the analysis into the eight steps used by a companion note: (1) Air scattering, (2) Neutron production in the ship and cargo, (3) Target detection probability, (4) Signal produced by target, (5) Attenuation of signal by ship and cargo, (6) Attenuation of signal by air, (7) Geometric dilution, and (8) Detector Efficiency. The above analyses indicate that the dominant air scattering and loss mechanisms for particle remote sensing are calculable with reliable and accepted tools. They make it clear that the conversion of proton beams into neutron sources rapidly goes to completion in all but thinnest targets, which means that proton interrogation is for all purposes executed by neutrons. Diffusion models and limiting approximations to them are simple and credible - apart from uncertainty over the cross sections to be used in them - and uncertainty over the structure of the vessels investigated. Multiplication is essentially unknown, in part because it depends on the details of the target and its shielding, which are unlikely to be known in advance. Attenuation of neutron fluxes on the way out are more complicated due to geometry, the spectrum of fission neutrons, and the details of their slowing down during egress. The attenuation by air is large but less uncertain. Detectors and technology are better known. The overall convolution of these effects lead to large but arguably tolerable levels of attenuation of input beams and output signals. That is particularly the case for small, mobile sensors, which can more than compensate for size with proximity to operate reliably while remaining below flux limits. Overall, the estimates used here appear to be of adequate accuracy for decisions. That assessment is strengthened by their agreement with companion calculations.

  20. Pump element for a tube pump

    DEFF Research Database (Denmark)

    2011-01-01

    The invention relates to a tube pump comprising a tube and a pump element inserted in the tube, where the pump element comprises a rod element and a first and a second non-return valve member positioned a distance apart on the rod element. The valve members are oriented in the same direction...... portion acts to alternately close and open the valve members thereby generating a fluid flow through the tube. The invention further relates to a pump element comprising at least two non-return valve members connected by a rod element, and for insertion in an at least partly flexible tube in such tube...... pump as mentioned above, thereby acting to generate a fluid flow through the tube upon repeated deformation of the tube between the two valve members. The pump element may comprise a connecting part for coupling to another tube and may comprise a sealing part establishing a fluid tight connection...

  1. Extracellular vesicles as emerging intercellular communicasomes.

    Science.gov (United States)

    Yoon, Yae Jin; Kim, Oh Youn; Gho, Yong Song

    2014-10-01

    All living cells release extracellular vesicles having pleiotropic functions in intercellular communication. Mammalian extracellular vesicles, also known as exosomes and microvesicles, are spherical bilayered proteolipids composed of various bioactive molecules, including RNAs, DNAs, proteins, and lipids. Extracellular vesicles directly and indirectly control a diverse range of biological processes by transferring membrane proteins, signaling molecules, mRNAs, and miRNAs, and activating receptors of recipient cells. The active interaction of extracellular vesicles with other cells regulates various physiological and pathological conditions, including cancer, infectious diseases, and neurodegenerative disorders. Recent developments in high-throughput proteomics, transcriptomics, and lipidomics tools have provided ample data on the common and specific components of various types of extracellular vesicles. These studies may contribute to the understanding of the molecular mechanism involved in vesicular cargo sorting and the biogenesis of extracellular vesicles, and, further, to the identification of disease-specific biomarkers. This review focuses on the components, functions, and therapeutic and diagnostic potential of extracellular vesicles under various pathophysiological conditions.

  2. Structure of Amphiphilic Terpolymer Raspberry Vesicles

    Directory of Open Access Journals (Sweden)

    Yingying Guo

    2017-07-01

    Full Text Available Terpolymer raspberry vesicles contain domains of different chemical affinities. They are potential candidates as multi-compartment cargo carriers. Their efficacy depends on their stability and load capacity. Using a model star terpolymer system in an aqueous solution, a dissipative particle dynamic (DPD simulation is employed to investigate how equilibrium aggregate structures are affected by polymer concentration and pairwise interaction energy in a solution. It is shown that a critical mass of polymer is necessary for vesicle formation. The free energy of the equilibrium aggregates are calculated and the results show that the transition from micelles to vesicles is governed by the interactions between the longest solvophobic block and the solvent. In addition, the ability of vesicles to encapsulate solvent is assessed. It is found that reducing the interaction energy favours solvent encapsulation, although solvent molecules can permeate through the vesicle’s shell when repulsive interactions among monomers are low. Thus, one can optimize the loading capacity and the release rate of the vesicles by turning pairwise interaction energies of the polymer and the solvent. The ability to predict and control these aspects of the vesicles is an essential step towards designing vesicles for specific purposes.

  3. Gastrostomy feeding tube - pump - child

    Science.gov (United States)

    ... tube feeding; PEG tube care; Feeding - gastrostomy tube - pump; G-tube - pump; Gastrostomy button - pump; Bard Button - pump; MIC-KEY - pump ... Gather supplies: Feeding pump (electronic or battery powered) Feeding ... pump (includes a feeding bag, drip chamber, roller clamp, ...

  4. Illuminating the physiology of extracellular vesicles.

    Science.gov (United States)

    Choi, Hongyoon; Lee, Dong Soo

    2016-04-16

    Extracellular vesicles play a crucial role in intercellular communication by transmitting biological materials from donor cells to recipient cells. They have pathophysiologic roles in cancer metastasis, neurodegenerative diseases, and inflammation. Extracellular vesicles also show promise as emerging therapeutics, with understanding of their physiology including targeting, distribution, and clearance therefore becoming an important issue. Here, we review recent advances in methods for tracking and imaging extracellular vesicles in vivo and critically discuss their systemic distribution, targeting, and kinetics based on up-to-date evidence in the literature.

  5. Classification, Functions, and Clinical Relevance of Extracellular Vesicles

    NARCIS (Netherlands)

    van der Pol, Edwin; Böing, Anita N.; Harrison, Paul; Sturk, Augueste; Nieuwland, Rienk

    2012-01-01

    Both eukaryotic and prokaryotic cells release small, phospholipid-enclosed vesicles into their environment. Why do cells release vesicles? Initial studies showed that eukaryotic vesicles are used to remove obsolete cellular molecules. Although this release of vesicles is beneficial to the cell, the

  6. Vesicle-MaNiA: extracellular vesicles in liquid biopsy and cancer

    OpenAIRE

    Torrano, Veronica; Royo, Felix; Peinado, Héctor; Loizaga-Iriarte, Ana; Unda, Miguel; Falcón-Perez, Juan M.; Carracedo, Arkaitz

    2016-01-01

    Normal and tumor cells shed vesicles to the environment. Within the large family of extracellular vesicles, exosomes and microvesicles have attracted much attention in the recent years. Their interest ranges from mediators of cancer progression, inflammation, immune regulation and metastatic niche regulation, to non-invasive biomarkers of disease. In this respect, the procedures to purify and analyze extracellular vesicles have quickly evolved and represent a source of variability for data in...

  7. Hybrid, Nanoscale Phospholipid/Block Copolymer Vesicles

    Directory of Open Access Journals (Sweden)

    Bo Liedberg

    2013-09-01

    Full Text Available Hybrid phospholipid/block copolymer vesicles, in which the polymeric membrane is blended with phospholipids, display interesting self-assembly behavior, incorporating the robustness and chemical versatility of polymersomes with the softness and biocompatibility of liposomes. Such structures can be conveniently characterized by preparing giant unilamellar vesicles (GUVs via electroformation. Here, we are interested in exploring the self-assembly and properties of the analogous nanoscale hybrid vesicles (ca. 100 nm in diameter of the same composition prepared by film-hydration and extrusion. We show that the self-assembly and content-release behavior of nanoscale polybutadiene-b-poly(ethylene oxide (PB-PEO/1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC hybrid phospholipid/block copolymer vesicles can be tuned by the mixing ratio of the amphiphiles. In brief, these hybrids may provide alternative tools for drug delivery purposes and molecular imaging/sensing applications and clearly open up new avenues for further investigation.

  8. Stability of Spherical Vesicles in Electric Fields

    Science.gov (United States)

    2010-01-01

    The stability of spherical vesicles in alternating (ac) electric fields is studied theoretically for asymmetric conductivity conditions across their membranes. The vesicle deformation is obtained from a balance between the curvature elastic energies and the work done by the Maxwell stresses. The present theory describes and clarifies the mechanisms for the four types of morphological transitions observed experimentally on vesicles exposed to ac fields in the frequency range from 500 to 2 × 107 Hz. The displacement currents across the membranes redirect the electric fields toward the membrane normal to accumulate electric charges by the Maxwell−Wagner mechanism. These accumulated electric charges provide the underlying molecular mechanism for the morphological transitions of vesicles as observed on the micrometer scale. PMID:20575588

  9. Kinetic regulation of coated vesicle secretion

    CERN Document Server

    Foret, Lionel

    2008-01-01

    The secretion of vesicles for intracellular transport often rely on the aggregation of specialized membrane-bound proteins into a coat able to curve cell membranes. The nucleation and growth of a protein coat is a kinetic process that competes with the energy-consuming turnover of coat components between the membrane and the cytosol. We propose a generic kinetic description of coat assembly and the formation of coated vesicles, and discuss its implication to the dynamics of COP vesicles that traffic within the Golgi and with the Endoplasmic Reticulum. We show that stationary coats of fixed area emerge from the competition between coat growth and the recycling of coat components, in a fashion resembling the treadmilling of cytoskeletal filaments. We further show that the turnover of coat components allows for a highly sensitive switching mechanism between a quiescent and a vesicle producing membrane, upon a slowing down of the exchange kinetics. We claim that the existence of this switching behaviour, also tri...

  10. Mutations in Synaptojanin Disrupt Synaptic Vesicle Recycling

    OpenAIRE

    Harris, Todd W.; Hartwieg, Erika; Horvitz, H. Robert; Jorgensen, Erik M.

    2000-01-01

    Synaptojanin is a polyphosphoinositide phosphatase that is found at synapses and binds to proteins implicated in endocytosis. For these reasons, it has been proposed that synaptojanin is involved in the recycling of synaptic vesicles. Here, we demonstrate that the unc-26 gene encodes the Caenorhabditis elegans ortholog of synaptojanin. unc-26 mutants exhibit defects in vesicle trafficking in several tissues, but most defects are found at synaptic termini. Specifically, we observed defects in ...

  11. Concentration-Independent Spontaneously Forming Biomimetric Vesicles

    Science.gov (United States)

    Nieh, M.-P.; Harroun, T. A.; Raghunathan, V. A.; Glinka, C. J.; Katsaras, J.

    2003-10-01

    In this Letter we present small-angle neutron scattering data from a biomimetic system composed of the phospholipids dimyristoyl and dihexanoyl phosphorylcholine (DMPC and DHPC, respectively). Doping DMPC-DHPC multilamellar vesicles with either the negatively charged lipid dimyristoyl phosphorylglycerol (DMPG, net charge -1) or the divalent cation, calcium (Ca2+), leads to the spontaneous formation of energetically stabilized monodisperse unilamellar vesicles whose radii are concentration independent and in contrast with previous experimental observations.

  12. Labeling Extracellular Vesicles for Nanoscale Flow Cytometry

    OpenAIRE

    Aizea Morales-Kastresana; Bill Telford; Musich, Thomas A.; Katherine McKinnon; Cassandra Clayborne; Zach Braig; Ari Rosner; Thorsten Demberg; Watson, Dionysios C.; Karpova, Tatiana S.; Freeman, Gordon J.; DeKruyff, Rosemarie H.; Pavlakis, George N.; Masaki Terabe; Marjorie Robert-Guroff

    2017-01-01

    Extracellular vesicles (EVs), including exosomes and microvesicles, are 30?800?nm vesicles that are released by most cell types, as biological packages for intercellular communication. Their importance in cancer and inflammation makes EVs and their cargo promising biomarkers of disease and cell-free therapeutic agents. Emerging high-resolution cytometric methods have created a pressing need for efficient fluorescent labeling procedures to visualize and detect EVs. Suitable labels must be brig...

  13. Insulin pump (image)

    Science.gov (United States)

    The catheter at the end of the insulin pump is inserted through a needle into the abdominal ... with diabetes. Dosage instructions are entered into the pump's small computer and the appropriate amount of insulin ...

  14. Actin-cytoskeleton rearrangement modulates proton-induced uptake

    Energy Technology Data Exchange (ETDEWEB)

    Ben-Dov, Nadav [Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv (Israel); Korenstein, Rafi, E-mail: korens@post.tau.ac.il [Department of Physiology and Pharmacology, Faculty of Medicine, Tel-Aviv University, 69978 Tel-Aviv (Israel)

    2013-04-15

    Recently it has been shown that elevating proton concentration at the cell surface stimulates the formation of membrane invaginations and vesicles accompanied by an enhanced uptake of macromolecules. While the initial induction of inward membrane curvature was rationalized in terms of proton-based increase of charge asymmetry across the membrane, the mechanisms underlying vesicle formation and its scission are still unknown. In light of the critical role of actin in vesicle formation during endocytosis, the present study addresses the involvement of cytoskeletal actin in proton-induced uptake (PIU). The uptake of dextran-FITC is used as a measure for the factual fraction of inward invaginations that undergo scission from the cell's plasma membrane. Our findings show that the rate of PIU in suspended cells is constant, whereas the rate of PIU in adherent cells is gradually increased in time, saturating at the level possessed by suspended cells. This is consistent with pH induced gradual degradation of stress-fibers in adherent cells. Wortmannin and calyculin-A are able to elevate PIU by 25% in adherent cells but not in suspended cells, while cytochalasin-D, rapamycin and latrunculin-A elevate PIU both in adherent and suspended cells. However, extensive actin depolymerization by high concentrations of latrunculin-A is able to inhibit PIU. We conclude that proton-induced membrane vesiculation is restricted by the actin structural resistance to the plasma membrane bending. Nevertheless, a certain degree of cortical actin restructuring is required for the completion of the scission process. - Highlights: ► Acidification of cells' exterior enhances uptake of macromolecules by the cells. ► Disruption of actin stress fibers leads to enhancement of proton induced uptake. ► Extensive depolymerization of cellular actin attenuates proton-induced uptake.

  15. Cellular Phenotype and Extracellular Vesicles: Basic and Clinical Considerations

    OpenAIRE

    Quesenberry, Peter J.; Goldberg, Laura R.; Aliotta, Jason M.; Mark S Dooner; Pereira, Mandy G.; Wen, Sicheng; Camussi, Giovanni

    2014-01-01

    Early work on platelet and erythrocyte vesicles interpreted the phenomena as a discard of material from cells. Subsequently, vesicles were studied as possible vaccines and, most recently, there has been a focus on the effects of vesicles on cell fate. Recent studies have indicated that extracellular vesicles, previously referred to as microvesicles or exosomes, have the capacity to change the phenotype of neighboring cells. Extensive work has shown that vesicles derived from either the lung o...

  16. Hierarchical unilamellar vesicles of controlled compositional heterogeneity.

    Directory of Open Access Journals (Sweden)

    Maik Hadorn

    Full Text Available Eukaryotic life contains hierarchical vesicular architectures (i.e. organelles that are crucial for material production and trafficking, information storage and access, as well as energy production. In order to perform specific tasks, these compartments differ among each other in their membrane composition and their internal cargo and also differ from the cell membrane and the cytosol. Man-made structures that reproduce this nested architecture not only offer a deeper understanding of the functionalities and evolution of organelle-bearing eukaryotic life but also allow the engineering of novel biomimetic technologies. Here, we show the newly developed vesicle-in-water-in-oil emulsion transfer preparation technique to result in giant unilamellar vesicles internally compartmentalized by unilamellar vesicles of different membrane composition and internal cargo, i.e. hierarchical unilamellar vesicles of controlled compositional heterogeneity. The compartmentalized giant unilamellar vesicles were subsequently isolated by a separation step exploiting the heterogeneity of the membrane composition and the encapsulated cargo. Due to the controlled, efficient, and technically straightforward character of the new preparation technique, this study allows the hierarchical fabrication of compartmentalized giant unilamellar vesicles of controlled compositional heterogeneity and will ease the development of eukaryotic cell mimics that resemble their natural templates as well as the fabrication of novel multi-agent drug delivery systems for combination therapies and complex artificial microreactors.

  17. Elastic energy of polyhedral bilayer vesicles.

    Science.gov (United States)

    Haselwandter, Christoph A; Phillips, Rob

    2011-06-01

    In recent experiments [M. Dubois, B. Demé, T. Gulik-Krzywicki, J.-C. Dedieu, C. Vautrin, S. Désert, E. Perez, and T. Zemb, Nature (London) 411, 672 (2001)] the spontaneous formation of hollow bilayer vesicles with polyhedral symmetry has been observed. On the basis of the experimental phenomenology it was suggested [M. Dubois, V. Lizunov, A. Meister, T. Gulik-Krzywicki, J. M. Verbavatz, E. Perez, J. Zimmerberg, and T. Zemb, Proc. Natl. Acad. Sci. USA 101, 15082 (2004)] that the mechanism for the formation of bilayer polyhedra is minimization of elastic bending energy. Motivated by these experiments, we study the elastic bending energy of polyhedral bilayer vesicles. In agreement with experiments, and provided that excess amphiphiles exhibiting spontaneous curvature are present in sufficient quantity, we find that polyhedral bilayer vesicles can indeed be energetically favorable compared to spherical bilayer vesicles. Consistent with experimental observations we also find that the bending energy associated with the vertices of bilayer polyhedra can be locally reduced through the formation of pores. However, the stabilization of polyhedral bilayer vesicles over spherical bilayer vesicles relies crucially on molecular segregation of excess amphiphiles along the ridges rather than the vertices of bilayer polyhedra. Furthermore, our analysis implies that, contrary to what has been suggested on the basis of experiments, the icosahedron does not minimize elastic bending energy among arbitrary polyhedral shapes and sizes. Instead, we find that, for large polyhedron sizes, the snub dodecahedron and the snub cube both have lower total bending energies than the icosahedron.

  18. Endothelial Extracellular Vesicles-Promises and Challenges.

    Science.gov (United States)

    Hromada, Carina; Mühleder, Severin; Grillari, Johannes; Redl, Heinz; Holnthoner, Wolfgang

    2017-01-01

    Extracellular vesicles, including exosomes, microparticles, and apoptotic bodies, are phospholipid bilayer-enclosed vesicles that have once been considered as cell debris lacking biological functions. However, they have recently gained immense interest in the scientific community due to their role in intercellular communication, immunity, tissue regeneration as well as in the onset, and progression of various pathologic conditions. Extracellular vesicles of endothelial origin have been found to play a versatile role in the human body, since they are on the one hand known to contribute to cardiovascular diseases, but on the other hand have also been reported to promote endothelial cell survival. Hence, endothelial extracellular vesicles hold promising therapeutic potential to be used as a new tool to detect as well as treat a great number of diseases. This calls for clinically approved, standardized, and efficient isolation and characterization protocols to harvest and purify endothelial extracellular vesicles. However, such methods and techniques to fulfill stringent requirements for clinical trials have yet to be developed or are not harmonized internationally. In this review, recent advances and challenges in the field of endothelial extracellular vesicle research are discussed and current problems and limitations regarding isolation and characterization are pointed out.

  19. Rotary magnetic heat pump

    Science.gov (United States)

    Kirol, Lance D.

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  20. Prevalência de alterações proliferativas gástricas em pacientes com uso crônico de inibidores de bomba de prótons Prevalence of gastric proliferative changes in patients with chronic use of proton pump inhibitor agents

    Directory of Open Access Journals (Sweden)

    Vivian de Souza Menegassi

    2010-09-01

    associação entre idade e alterações proliferativas apresentou significância estatística.BACKGROUND: The medications most often prescribed and used chronically by patients with dyspeptic symptoms belong to the group of inhibitors of proton pump whose main representative is omeprazole, used clinically about 20 years. Recent studies have postulated the relationship between chronic use of this medication and macroscopic and microscopic proliferative changes in mucosal of gastric body, especially the fundic gland polyps. AIM: To analyze the frequency and type of gastric proliferative changes in chronic users of proton pump inhibitors proton and its association with age, dose, time of use, symptoms and Helicobacter pylori infection. METHODS: A survey of prevalence was conducted in Digestive Endoscopy Service, Hospital de Clínicas, Federal University of Paraná, using questionnaire referring the use of these drugs and performed in subjects using this class of drugs during at least 12 months prior to the endoscopy. Gastric biopsies of fundus, body and antrum were performed in all patients. Polyps were removed when present for histopathological analysis. Research on Helicobacter pylori was done by urease test and histopathology. RESULTS: Twenty-two individuals were included of which six (27.3% had proliferative changes of the mucosa. Of these, two (9.1% had sporadic fundic polyps and four only microscopic proliferative change as cystic glandular formation. Statistic significant (p 60 years and these changes was found. There was no association between dose of use, time of use, symptoms and Helicobacter pylori infection. CONCLUSIONS: It was observed the existence of proliferative mucosa changes in individuals with chronic use of inhibitors of proton pump. In this group, the association between age and proliferative changes was significant.

  1. Vesicle-to-micelle transition in aqueous solutions of amphiphilic calixarene derivatives

    Science.gov (United States)

    Micali, Norberto; Villari, Valentina; Consoli, Grazia M. L.; Cunsolo, Francesca; Geraci, Corrada

    2006-05-01

    Structure and conformation of spontaneous self-assembled calix[8]arenes derivatives are studied by means of static and dynamic light scattering and electrophoretic mobility. These amphiphilic molecules are in the aggregated form in aqueous solution, in a wide range of pH ; they take a vesicle structure in neutral and basic pH environment, but, in relatively strong acidic conditions (below pH=4.5 ), a transition from vesicle to micelle occurs. The structural change is driven by the surface charge density. At neutral pH calix[8]arenes take a negative surface charge, which prevents coagulation and ensures stability; at acidic pH the surface charge tend to become positive because of the protonation of the hydrophilic head. These pH -responsive aggregates, able to release an encapsulated hydrophilic guest, are promising systems for application as nanocarriers.

  2. Cimetidine transport in rabbit renal cortical brush-border membrane vesicles

    Energy Technology Data Exchange (ETDEWEB)

    McKinney, T.D.; Kunnemann, M.E.

    1987-03-01

    Cimetidine is an organic cation and commonly prescribed drug that is eliminated primarily by proximal renal tubular secretion. The present studies evaluated cimetidine transport in rabbit renal cortical brush-border membrane vesicles (BBMV). (/sup 3/H)Cimetidine uptake varied inversely with media osmolarity and was stimulated with uphill transport above equilibrium values (overshoot) produced by an initial proton gradient directed from the vesicle interior outwardly. Uphill transport occurred earlier and was of greater magnitude at 25/sup 0/C than at 5/sup 0/C. pH-stimulated (/sup 3/H)cimetidine uptake was inhibited by excess nonradiolabeled cimetidine, quinidine, and procainamide but was affected little by probenecid. Tetraethylammonium inhibited cimetidine uptake in the presence and absence of an initial proton gradient, indicating that nonionic diffusion and simple diffusion cannot totally account for cimetidine transport in BBMV. Preloading BBMV with an excess of procainamide enhanced cimetidine uptake. These results are consistent with the hypothesis that cimetidine is transported across BBMV by organic cation-proton exchange.

  3. Extracellular Vesicles in Metabolic Syndrome.

    Science.gov (United States)

    Martínez, M Carmen; Andriantsitohaina, Ramaroson

    2017-05-12

    Metabolic syndrome defines a cluster of interrelated risk factors for cardiovascular disease and diabetes mellitus. These factors include metabolic abnormalities, such as hyperglycemia, elevated triglyceride levels, low high-density lipoprotein cholesterol levels, high blood pressure, and obesity, mainly central adiposity. In this context, extracellular vesicles (EVs) may represent novel effectors that might help to elucidate disease-specific pathways in metabolic disease. Indeed, EVs (a terminology that encompasses microparticles, exosomes, and apoptotic bodies) are emerging as a novel mean of cell-to-cell communication in physiology and pathology because they represent a new way to convey fundamental information between cells. These microstructures contain proteins, lipids, and genetic information able to modify the phenotype and function of the target cells. EVs carry specific markers of the cell of origin that make possible monitoring their fluctuations in the circulation as potential biomarkers inasmuch their circulating levels are increased in metabolic syndrome patients. Because of the mixed components of EVs, the content or the number of EVs derived from distinct cells of origin, the mode of cell stimulation, and the ensuing mechanisms for their production, it is difficult to attribute specific functions as drivers or biomarkers of diseases. This review reports recent data of EVs from different origins, including endothelial, smooth muscle cells, macrophages, hepatocytes, adipocytes, skeletal muscle, and finally, those from microbiota as bioeffectors of message, leading to metabolic syndrome. Depicting the complexity of the mechanisms involved in their functions reinforce the hypothesis that EVs are valid biomarkers, and they represent targets that can be harnessed for innovative therapeutic approaches. © 2017 American Heart Association, Inc.

  4. Proton movies

    CERN Multimedia

    2009-01-01

    A humorous short film made by three secondary school students received an award at a Geneva film festival. Even without millions of dollars or Hollywood stars at your disposal, it is still possible to make a good science fiction film about CERN. That is what three students from the Collège Madame de Staël in Carouge, near Geneva, demonstrated. For their amateur short film on the LHC, they were commended by the jury of the video and multimedia festival for schools organised by the "Media in education" service of the Canton of Geneva’s Public Education Department. The film is a spoof of a television news report on the LHC start-up. In sequences full of humour and imagination, the reporter conducts interviews with a very serious "Professor Sairne", some protons preparing for their voyage and even the neutrons that were rejected by the LHC. "We got the idea of making a film about CERN at the end of the summer," explains Lucinda Päsche, one of the three students. "We did o...

  5. A two phase field model for tracking vesicle-vesicle adhesion.

    Science.gov (United States)

    Gu, Rui; Wang, Xiaoqiang; Gunzburger, Max

    2016-11-01

    A multi-phase-field model for simulating the adhesion between two vesicles is constructed. Two phase field functions are introduced to simulate each of the two vesicles. An energy model is defined which accounts for the elastic bending energy of each vesicle and the contact potential energy between the two vesicles; the vesicle volume and surface area constraints are imposed using a penalty method. Numerical results are provided to verify the efficacy of our model and to provide visual illustrations of the different types of contact. The method can be adjusted to solve endocytosis problems by modifying the bending rigidity coefficients of the two elastic bending energies. The method can also be extended to simulate multi-cell adhesions, one example of which is erythrocyte rouleaux. A comparison with laboratory observations demonstrates the effectiveness of the multi-phase field approach.

  6. Insights into the self-reproduction of oleate vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Stano, P [' Enrico Fermi' Centre, Compendio Viminale, 00184 Rome (Italy); Wehrli, E [Electron Microscopy Centre (EMEZ), Applied Physics Institute, ETH Hoenggerberg, 8093 Zurich (Switzerland); Luisi, P L [Biology Department, University of RomaTre, Viale Marconi 446, 00146 Rome (Italy)

    2006-08-23

    In view of the importance of vesicles as models for early cells, several groups have started work looking for conditions under which vesicles can undergo growth and division. Evidence for growth and division has been obtained with the help of ferritin-labelled vesicles; furthermore, it has been shown that in such processes the vesicle size distribution is largely conserved. In both cases, the data suggest that the process under study is mainly characterized by vesicle growth and eventually division into daughter vesicles. However, direct evidence for vesicle division has not been obtained. In this paper, mostly based on freeze-fracture electron microscopy, we describe conditions under which for the first time division intermediates can be trapped in the form of twin vesicles. This finding, together with supporting dynamic light scattering and fluorescence investigations, permits us to establish some additional points in the mechanism of vesicle self-reproduction.

  7. Unraveling the mechanism of a reversible photoactivated molecular proton crane.

    Science.gov (United States)

    van der Loop, Tibert H; Ruesink, Freek; Amirjalayer, Saeed; Sanders, Hans J; Buma, Wybren J; Woutersen, S

    2014-11-13

    We study the structural dynamics of the photoactivated molecular proton crane 7-hydroxy-8-(morpholinomethyl)quinoline using femtosecond UV-pump IR-probe spectroscopy. Upon electronic excitation, a proton is transferred from the hydroxy to the amine group located on the rotatable morpholino side group. This morpholino group subsequently delivers the proton to the aromatic quinoline nitrogen by rotation around the C-C bond. Time-resolved vibrational spectroscopy allows us to study this process in unprecedented detail. We find that the transport of the proton involves multiple time scales. Upon photoexcitation, the OH proton is transferred within <300 fs to the morpholino side group. After this, the intramolecular hydrogen bond that locks the crane arm breaks with a time constant of 36 ± 1 ps. Subsequently, the protonated crane arm rotates with a time constant of 334 ± 12 ps to deliver the proton at the quinoline moiety. After the proton crane has returned to its electronic ground state with a time constant 700 ± 22 ps, the proton is transferred back from the quinoline nitrogen to the negatively charged O atom. The time constant of the back rotation is 39.8 ± 0.2 ns, about 200 times slower than the forward proton transfer.

  8. Mechanics of post-fusion exocytotic vesicle.

    Science.gov (United States)

    Stephens, Thomas; Wu, Zhanghan; Liu, Jian

    2017-05-23

    Exocytosis is an important cellular process controlled by metabolic signaling. It involves vesicle fusion to the plasma membrane, followed by the opening of a fusion pore, and the subsequent release of the vesicular lumen content into the extracellular space. While most modeling efforts focus on the events leading to membrane fusion, how the vesicular membrane remodels after fusing to plasma membrane remains unclear. This latter event dictates the nature and the efficiency of exocytotic vesicular secretions, and is thus critical for exocytotic function. We provide a generic membrane mechanical model to systematically study the fate of post-fusion vesicles. We show that while membrane stiffness favors full-collapse vesicle fusion into the plasma membrane, the intravesicular pressure swells the vesicle and causes the fusion pore to shrink. Dimensions of the vesicle and its associated fusion pore further modulate this mechanical antagonism. We systematically define the mechanical conditions that account for the full spectrum of the observed vesicular secretion modes. Our model therefore can serve as a unified theoretical framework that sheds light on the elaborate control mechanism of exocytosis.

  9. Astrocytic Vesicle Mobility in Health and Disease

    Directory of Open Access Journals (Sweden)

    Robert Zorec

    2013-05-01

    Full Text Available Astrocytes are no longer considered subservient to neurons, and are, instead, now understood to play an active role in brain signaling. The intercellular communication of astrocytes with neurons and other non-neuronal cells involves the exchange of molecules by exocytotic and endocytotic processes through the trafficking of intracellular vesicles. Recent studies of single vesicle mobility in astrocytes have prompted new views of how astrocytes contribute to information processing in nervous tissue. Here, we review the trafficking of several types of membrane-bound vesicles that are specifically involved in the processes of (i intercellular communication by gliotransmitters (glutamate, adenosine 5'-triphosphate, atrial natriuretic peptide, (ii plasma membrane exchange of transporters and receptors (EAAT2, MHC-II, and (iii the involvement of vesicle mobility carrying aquaporins (AQP4 in water homeostasis. The properties of vesicle traffic in astrocytes are discussed in respect to networking with neighboring cells in physiologic and pathologic conditions, such as amyotrophic lateral sclerosis, multiple sclerosis, and states in which astrocytes contribute to neuroinflammatory conditions.

  10. Mechanics of post-fusion exocytotic vesicle

    Science.gov (United States)

    Stephens, Thomas; Wu, Zhanghan; Liu, Jian

    2017-06-01

    Exocytosis is an important cellular process controlled by metabolic signaling. It involves vesicle fusion to the plasma membrane, followed by the opening of a fusion pore, and the subsequent release of the vesicular lumen content into the extracellular space. While most modeling efforts focus on the events leading to membrane fusion, how the vesicular membrane remodels after fusing to plasma membrane remains unclear. This latter event dictates the nature and the efficiency of exocytotic vesicular secretions, and is thus critical for exocytotic function. We provide a generic membrane mechanical model to systematically study the fate of post-fusion vesicles. We show that while membrane stiffness favors full-collapse vesicle fusion into the plasma membrane, the intravesicular pressure swells the vesicle and causes the fusion pore to shrink. Dimensions of the vesicle and its associated fusion pore further modulate this mechanical antagonism. We systematically define the mechanical conditions that account for the full spectrum of the observed vesicular secretion modes. Our model therefore can serve as a unified theoretical framework that sheds light on the elaborate control mechanism of exocytosis.

  11. EXTRACELLULAR VESICLES: CLASSIFICATION, FUNCTIONS AND CLINICAL RELEVANCE

    Directory of Open Access Journals (Sweden)

    A. V. Oberemko

    2014-12-01

    Full Text Available This review presents a generalized definition of vesicles as bilayer extracellular organelles of all celular forms of life: not only eu-, but also prokaryotic. The structure and composition of extracellular vesicles, history of research, nomenclature, their impact on life processes in health and disease are discussed. Moreover, vesicles may be useful as clinical instruments for biomarkers, and they are promising as biotechnological drug. However, many questions in this area are still unresolved and need to be addressed in the future. The most interesting from the point of view of practical health care represents a direction to study the effect of exosomes and microvesicles in the development and progression of a particular disease, the possibility of adjusting the pathological process by means of extracellular vesicles of a particular type, acting as an active ingredient. Relevant is the further elucidation of the role and importance of exosomes to the surrounding cells, tissues and organs at the molecular level, the prospects for the use of non-cellular vesicles as biomarkers of disease.

  12. Performance of a pump system for diode-pumped lasers

    Science.gov (United States)

    Stratan, Aurel; Fenic, Constantin G.; Dabu, Razvan V.; Herisanu, Nicolae A.; Luculescu, C.; Sporea, Dan G.; Dumitru, Gabriel; Iordache, Gheorghe

    1998-07-01

    We have developed a laser-diode pump system for continuous-wave end-pumping of Nd:YAG lasers. The pump system includes a pair of 1 W diode-arrays mounted in coaxial enclosures, a driver unit and the pump optics. The array wavelength was temperature tuned to achieve the maximum absorption of the pump radiation in the Nd:YAG crystal. The characteristics of the pump system are presented and the pump-beam profile is investigated.

  13. Hemin reconstitutes proton extrusion in an H+-ATPase-negative mutant of Lactococcus lactis

    DEFF Research Database (Denmark)

    Blank, L.M.; Købmann, Brian Jensen; Michelsen, Ole

    2001-01-01

    H+-ATPase is considered essential for growth of Lactococcus lactis. However, media containing hemin restored the aerobic growth of an H+-ATPase-negative mutant, suggesting that hemin complements proton extrusion. We show that inverted membrane vesicles prepared from hemin-grown L. lactis cells...

  14. Proton-air and proton-proton cross sections

    Directory of Open Access Journals (Sweden)

    Ulrich Ralf

    2013-06-01

    Full Text Available Different attempts to measure hadronic cross sections with cosmic ray data are reviewed. The major results are compared to each other and the differences in the corresponding analyses are discussed. Besides some important differences, it is crucial to see that all analyses are based on the same fundamental relation of longitudinal air shower development to the observed fluctuation of experimental observables. Furthermore, the relation of the measured proton-air to the more fundamental proton-proton cross section is discussed. The current global picture combines hadronic proton-proton cross section data from accelerator and cosmic ray measurements and indicates a good consistency with predictions of models up to the highest energies.

  15. Functionally polymerized surfactant vesicles: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tundo, P.; Kippenberger, D.J.; Klahn, P.L.; Prieto, N.E.; Fendler, J.H.

    1982-01-27

    Bis(2-(10-undecenoyloxycarbony bromide, bis(2-(10-undecenoyloxycarbony (2-hydroxyethyl)methylammonium bromide, bis(2-(10-undecenoyloxycarbony acid, bis(2-(10-undecenoyloxycarbony allylbis(2-dodecanoyloxycarbon bromide, and dimethyl-n-hexadecyl (10-(p-vin decyl)ammonium bromide have been synthesized. The predominantly single compartment bilayer vesicles formed from these surfactants could be polymerized either by exposure to ultraviolet irradiation or by the use of azoisobutyronitrile as an initiator. The presence of vesicles (unpolymerized and polymeric) has been demonstrated by electron micrography, H/sup 1/ NMR, gel filtration, phase transition, turbidity changes, substrate entrapment, and permeability. Polymerized vesicles are considerably more stable and less permeable and have reduced rates of turbidity changes compared to their unpolymerized counterparts. 19 references.

  16. Directed vesicle transport by diffusio-osmosis

    Science.gov (United States)

    Michler, D.; Shahidzadeh, N.; Sprik, R.; Bonn, D.

    2015-04-01

    We present a study on surfactant vesicles that spontaneously move towards an oil droplet that is deposited on a glass substrate. Tracer particles in the surfactant solution show that the motion is not self-propelled: the vesicles are entrained by a macroscopic hydrodynamic flow. Measurements of the flow velocity suggest that the flow is of diffusio-osmotic nature. The surfactant is observed to move into the oil phase which creates a gradient in ion concentration in the vicinity of the droplet. As the diffusion coefficients of the surfactant's co- and counter-ions differ, a charge separation takes place and an electric field arises. This electric field then generates a hydrodynamic flow along the charged glass substrate in which the vesicles are entrained.

  17. Functionalization of Block Copolymer Vesicle Surfaces

    Directory of Open Access Journals (Sweden)

    Wolfgang Meier

    2011-01-01

    Full Text Available In dilute aqueous solutions certain amphiphilic block copolymers self-assemble into vesicles that enclose a small pool of water with a membrane. Such polymersomes have promising applications ranging from targeted drug-delivery devices, to biosensors, and nanoreactors. Interactions between block copolymer membranes and their surroundings are important factors that determine their potential biomedical applications. Such interactions are influenced predominantly by the membrane surface. We review methods to functionalize block copolymer vesicle surfaces by chemical means with ligands such as antibodies, adhesion moieties, enzymes, carbohydrates and fluorophores. Furthermore, surface-functionalization can be achieved by self-assembly of polymers that carry ligands at their chain ends or in their hydrophilic blocks. While this review focuses on the strategies to functionalize vesicle surfaces, the applications realized by, and envisioned for, such functional polymersomes are also highlighted.

  18. Structure dynamics of the proton in liquid water probed with terahertz time-domain spectroscopy

    NARCIS (Netherlands)

    Tielrooij, K.J.; Timmer, R.L.A.; Bakker, H.J.; Bonn, M.

    2009-01-01

    We study the hydration of protons in liquid water using terahertz time-domain spectroscopy and polarization-resolved femtosecond midinfrared pump-probe spectroscopy. We observe that the addition of protons leads to a very strong decrease of the dielectric response of liquid water that corresponds to

  19. Electrohydrodynamics of a compound vesicle under an AC electric field.

    Science.gov (United States)

    Sinha, Kumari Priti; Thaokar, Rochish M

    2017-07-12

    Compound vesicles are relevant as simplified models for biological cells as well as in technological applications such as drug delivery. Characterization of these compound vesicles, especially the inner vesicle, remains a challenge. Similarly their response to electric field assumes importance in light of biomedical applications such as electroporation. Fields lower than that required for electroporation cause electrodeformation in vesicles and can be used to characterize their mechanical and electrical properties. A theoretical analysis of the electrohydrodynamics of a compound vesicle with outer vesicle of radius R o and an inner vesicle of radius [Formula: see text], is presented. A phase diagram for the compound vesicle is presented and elucidated using detailed plots of electric fields, free charges and electric stresses. The electrohydrodynamics of the outer vesicle in a compound vesicle shows a prolate-sphere and prolate-oblate-sphere shape transitions when the conductivity of the annular fluid is greater than the outer fluid, and vice-versa respectively, akin to single vesicle electrohydrodynamics reported in the literature. The inner vesicle in contrast shows sphere-prolate-sphere and sphere-prolate-oblate-sphere transitions when the inner fluid conductivity is greater and smaller than the annular fluid, respectively. Equations and methodology are provided to determine the bending modulus and capacitance of the outer as well as the inner membrane, thereby providing an easy way to characterize compound vesicles and possibly biological cells.

  20. Electrohydrodynamics of a compound vesicle under an AC electric field

    Science.gov (United States)

    Priti Sinha, Kumari; Thaokar, Rochish M.

    2017-07-01

    Compound vesicles are relevant as simplified models for biological cells as well as in technological applications such as drug delivery. Characterization of these compound vesicles, especially the inner vesicle, remains a challenge. Similarly their response to electric field assumes importance in light of biomedical applications such as electroporation. Fields lower than that required for electroporation cause electrodeformation in vesicles and can be used to characterize their mechanical and electrical properties. A theoretical analysis of the electrohydrodynamics of a compound vesicle with outer vesicle of radius R o and an inner vesicle of radius λ {{R}o} , is presented. A phase diagram for the compound vesicle is presented and elucidated using detailed plots of electric fields, free charges and electric stresses. The electrohydrodynamics of the outer vesicle in a compound vesicle shows a prolate-sphere and prolate-oblate-sphere shape transitions when the conductivity of the annular fluid is greater than the outer fluid, and vice-versa respectively, akin to single vesicle electrohydrodynamics reported in the literature. The inner vesicle in contrast shows sphere-prolate-sphere and sphere-prolate-oblate-sphere transitions when the inner fluid conductivity is greater and smaller than the annular fluid, respectively. Equations and methodology are provided to determine the bending modulus and capacitance of the outer as well as the inner membrane, thereby providing an easy way to characterize compound vesicles and possibly biological cells.

  1. Detection of pump degradation

    Energy Technology Data Exchange (ETDEWEB)

    Greene, R.H.; Casada, D.A.; Ayers, C.W. [and others

    1995-08-01

    This Phase II Nuclear Plant Aging Research study examines the methods of detecting pump degradation that are currently employed in domestic and overseas nuclear facilities. This report evaluates the criteria mandated by required pump testing at U.S. nuclear power plants and compares them to those features characteristic of state-of-the-art diagnostic programs and practices currently implemented by other major industries. Since the working condition of the pump driver is crucial to pump operability, a brief review of new applications of motor diagnostics is provided that highlights recent developments in this technology. The routine collection and analysis of spectral data is superior to all other technologies in its ability to accurately detect numerous types and causes of pump degradation. Existing ASME Code testing criteria do not require the evaluation of pump vibration spectra but instead overall vibration amplitude. The mechanical information discernible from vibration amplitude analysis is limited, and several cases of pump failure were not detected in their early stages by vibration monitoring. Since spectral analysis can provide a wealth of pertinent information concerning the mechanical condition of rotating machinery, its incorporation into ASME testing criteria could merit a relaxation in the monthly-to-quarterly testing schedules that seek to verify and assure pump operability. Pump drivers are not included in the current battery of testing. Operational problems thought to be caused by pump degradation were found to be the result of motor degradation. Recent advances in nonintrusive monitoring techniques have made motor diagnostics a viable technology for assessing motor operability. Motor current/power analysis can detect rotor bar degradation and ascertain ranges of hydraulically unstable operation for a particular pump and motor set. The concept of using motor current or power fluctuations as an indicator of pump hydraulic load stability is presented.

  2. A compact cryogenic pump

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gang; Caldwell, Shane; Clark, Jason A.; Gulick, Sidney; Hecht, Adam; Lascar, Daniel D.; Levand, Tony; Morgan, Graeme; Orford, Rodney; Savard, Guy; Sharma, Kumar S.; Van Schelt, Jonathon

    2016-04-01

    A centrifugal cryogenic pump has been designed at Argonne National Laboratory to circulate liquid nitrogen (LN2) in a closed circuit allowing the recovery of excess fluid. The pump can circulate LN2 at rates of 2-10 L/min, into a head of 0.5-3 m. Over four years of laboratory use the pump has proven capable of operating continuously for 50-100 days without maintenance.

  3. Vesicle-MaNiA: extracellular vesicles in liquid biopsy and cancer.

    Science.gov (United States)

    Torrano, Veronica; Royo, Felix; Peinado, Héctor; Loizaga-Iriarte, Ana; Unda, Miguel; Falcón-Perez, Juan M; Carracedo, Arkaitz

    2016-08-01

    Normal and tumor cells shed vesicles to the environment. Within the large family of extracellular vesicles, exosomes and microvesicles have attracted much attention in the recent years. Their interest ranges from mediators of cancer progression, inflammation, immune regulation and metastatic niche regulation, to non-invasive biomarkers of disease. In this respect, the procedures to purify and analyze extracellular vesicles have quickly evolved and represent a source of variability for data integration in the field. In this review, we provide an updated view of the potential of exosomes and microvesicles as biomarkers and the available technologies for their isolation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Optically pumped atoms

    CERN Document Server

    Happer, William; Walker, Thad

    2010-01-01

    Covering the most important knowledge on optical pumping of atoms, this ready reference is backed by numerous examples of modelling computation for optical pumped systems. The authors show for the first time that modern scientific computing software makes it practical to analyze the full, multilevel system of optically pumped atoms. To make the discussion less abstract, the authors have illustrated key points with sections of MATLAB codes. To make most effective use of contemporary mathematical software, it is especially useful to analyze optical pumping situations in the Liouville spa

  5. Champagne Heat Pump

    Science.gov (United States)

    Jones, Jack A.

    2004-01-01

    The term champagne heat pump denotes a developmental heat pump that exploits a cycle of absorption and desorption of carbon dioxide in an alcohol or other organic liquid. Whereas most heat pumps in common use in the United States are energized by mechanical compression, the champagne heat pump is energized by heating. The concept of heat pumps based on other absorption cycles energized by heat has been understood for years, but some of these heat pumps are outlawed in many areas because of the potential hazards posed by leakage of working fluids. For example, in the case of the water/ammonia cycle, there are potential hazards of toxicity and flammability. The organic-liquid/carbon dioxide absorption/desorption cycle of the champagne heat pump is similar to the water/ammonia cycle, but carbon dioxide is nontoxic and environmentally benign, and one can choose an alcohol or other organic liquid that is also relatively nontoxic and environmentally benign. Two candidate nonalcohol organic liquids are isobutyl acetate and amyl acetate. Although alcohols and many other organic liquids are flammable, they present little or no flammability hazard in the champagne heat pump because only the nonflammable carbon dioxide component of the refrigerant mixture is circulated to the evaporator and condenser heat exchangers, which are the only components of the heat pump in direct contact with air in habitable spaces.

  6. The role of extracellular vesicles in malaria biology and pathogenesis.

    Science.gov (United States)

    Sampaio, Natalia Guimaraes; Cheng, Lesley; Eriksson, Emily M

    2017-06-09

    In the past decade, research on the functions of extracellular vesicles in malaria has expanded dramatically. Investigations into the various vesicle types, from both host and parasite origin, has revealed important roles for extracellular vesicles in disease pathogenesis and susceptibility, as well as cell-cell communication and immune responses. Here, work relating to extracellular vesicles in malaria is reviewed, and the areas that remain unknown and require further investigations are highlighted.

  7. Adsorption of DOPC vesicles on hydrophobic substrates in the ...

    Indian Academy of Sciences (India)

    Administrator

    In the present study, the interaction between an intact DOPC vesicle and the hydropho- bic surface is mainly through van der Waals interac- tion. In presence of increasing concentrations of electrolytes, counter ions are present in the vicinity of the DOPC vesicle. As the vesicle approaches the solid substrate, the counter ions ...

  8. Role of Outer Membrane Vesicles of Bacteria

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 8. Role of Outer Membrance Vesicles of Bacteria. M V Jagannadham M K Chattopadhyay. General Article Volume 20 Issue 8 ... Keywords. Outer membrane ves ic les (OMVs); secretion; communication; virulence; antibiotic resistance; vaccines.

  9. Vesicle Pools: Lessons from Adrenal Chromaffin Cells

    Directory of Open Access Journals (Sweden)

    David R Stevens

    2011-02-01

    Full Text Available The adrenal chromaffin cell serves as a model system to study fast Ca2+-dependent exocytosis. Membrane capacitance measurements in combination with Ca2+ uncaging offers a temporal resolution in the millisecond range and reveals that catecholamine release occurs in three distinct phases. Release of a readily releasable (RRP and a slowly releasable (SRP pool are followed by sustained release, due to maturation and release of vesicles which were not release-ready at the start of the stimulus. Trains of depolarizations, a more physiological stimulus, induce release from a small immediately releasable pool of vesicles residing adjacent to calcium channels, as well as from the RRP. The SRP is poorly activated by depolarization. A sequential model, in which non-releasable docked vesicles are primed to a slowly releasable state, and then further mature to the readily releasable state, has been proposed. The docked state, dependent on membrane proximity, requires SNAP-25, synaptotagmin and syntaxin. The ablation or modification of SNAP-25 and syntaxin, components of the SNARE complex, as well as of synaptotagmin, the calcium sensor, and modulators such complexins and Snapin alter the properties and/or magnitudes of different phases of release, and in particular can ablate the RRP. These results indicate that the composition of the SNARE complex and its interaction with modulatory molecules drives priming and provides a molecular basis for different pools of releasable vesicles.

  10. Extracellular vesicles: fundamentals and clinical relevance

    Directory of Open Access Journals (Sweden)

    Wael Nassar

    2015-01-01

    Full Text Available All types of cells of eukaryotic organisms produce and release small nanovesicles into their extracellular environment. Early studies have described these vesicles as ′garbage bags′ only to remove obsolete cellular molecules. Valadi and colleagues, in 2007, were the first to discover the capability of circulating extracellular vesicles (EVs to horizontally transfer functioning gene information between cells. These extracellular vesicles express components responsible for angiogenesis promotion, stromal remodeling, chemoresistance, genetic exchange, and signaling pathway activation through growth factor/receptor transfer. EVs represent an important mode of intercellular communication by serving as vehicles for transfer between cells of membrane and cytosolic proteins, lipids, signaling proteins, and RNAs. They contribute to physiology and pathology, and they have a myriad of potential clinical applications in health and disease. Moreover, vesicles can pass the blood-brain barrier and may perhaps even be considered as naturally occurring liposomes. These cell-derived EVs not only represent a central mediator of the disease microenvironment, but their presence in the peripheral circulation may serve as a surrogate for disease biopsies, enabling real-time diagnosis and disease monitoring. In this review, we′ll be addressing the characteristics of different types of extracellular EVs, as well as their clinical relevance and potential as diagnostic markers, and also define therapeutic options.

  11. Compartmentalization and Transport in Synthetic Vesicles

    Directory of Open Access Journals (Sweden)

    Christine eSchmitt

    2016-02-01

    Full Text Available Nano-scale vesicles have become a popular tool in life sciences. Besides liposomes that are generated from phospholipids of natural origin, polymersomes fabricated of synthetic block copolymers enjoy increasing popularity, as they represent more versatile membrane building blocks that can be selected based on their specific physicochemical properties, like permeability, stability or chemical reactivity.In this review, we focus on the application of simple and nested artificial vesicles in synthetic biology. First, we provide an introduction into the utilization of multi-compartmented vesosomes as compartmentalized nano-scale bioreactors. In the bottom-up development of protocells from vesicular nano-reactors, the specific exchange of pathway intermediates across compartment boundaries represents a bottleneck for future studies. To date, most compartmented bioreactors rely on unspecific exchange of substrates and products. This is either based on changes in permeability of the coblock polymer shell by physicochemical triggers or by the incorporation of unspecific porin proteins into the vesicle membrane. Since the incorporation of membrane transport proteins into simple and nested artificial vesicles offers the potential for specific exchange of substances between subcompartments, it opens new vistas in the design of protocells. Therefore we devote the main part of the review to summarize the technical advances in the use of phospholipids and block copolymers for the reconstitution of membrane proteins.

  12. Towards traceable size determination of extracellular vesicles

    NARCIS (Netherlands)

    Varga, Zoltán; Yuana, Yuana; Grootemaat, Anita E.; van der Pol, Edwin; Gollwitzer, Christian; Krumrey, Michael; Nieuwland, Rienk

    2014-01-01

    Extracellular vesicles (EVs) have clinical importance due to their roles in a wide range of biological processes. The detection and characterization of EVs are challenging because of their small size, low refractive index, and heterogeneity. In this manuscript, the size distribution of an

  13. Functional transferred DNA within extracellular vesicles

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Jin [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Jiangsu Province (China); Wu, Gengze [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China); Jose, Pedro A. [Division of Nephrology, Department of Medicine and Physiology, University of Maryland, School of Medicine, Baltimore, MD 21201 (United States); Zeng, Chunyu, E-mail: Chunyuzeng01@163.com [Department of Cardiology, Daping Hospital, The Third Military Medical University, Chongqing 400042 (China)

    2016-11-15

    Extracellular vesicles