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Sample records for citrate phosphate double

  1. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Iron, citrate phosphate potassium... Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical..., citrate phosphate potassium complexes (PMN P-09-382; CAS No. 120579-31-9) is subject to reporting...

  2. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Iron, citrate phosphate potassium... Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical..., citrate phosphate potassium complexes (PMN P-09-382; CAS No. 120579-31-9) is subject to reporting...

  3. 40 CFR 721.10357 - Iron, citrate phosphate potassium complexes.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Iron, citrate phosphate potassium... Specific Chemical Substances § 721.10357 Iron, citrate phosphate potassium complexes. (a) Chemical..., citrate phosphate potassium complexes (PMN P-09-382; CAS No. 120579-31-9) is subject to reporting...

  4. Artificial citrate operon and Vitreoscilla hemoglobin gene enhanced mineral phosphate solubilizing ability of Enterobacter hormaechei DHRSS.

    PubMed

    Yadav, Kavita; Kumar, Chanchal; Archana, G; Kumar, G Naresh

    2014-10-01

    Mineral phosphate solubilization by bacteria is mediated through secretion of organic acids, among which citrate is one of the most effective. To overproduce citrate in bacterial systems, an artificial citrate operon comprising of genes encoding NADH-insensitive citrate synthase of E. coli and Salmonella typhimurium sodium-dependent citrate transporter was constructed. In order to improve its mineral phosphate solubilizing (MPS) ability, the citrate operon was incorporated into E. hormaechei DHRSS. The artificial citrate operon transformant secreted 7.2 mM citric acid whereas in the native strain, it was undetectable. The transformant released 0.82 mM phosphate in flask studies in buffered medium containing rock phosphate as sole P source. In fermenter studies, similar phenotype was observed under aerobic conditions. However, under microaerobic conditions, no citrate was detected and P release was not observed. Therefore, an artificial citrate gene cluster containing Vitreoscilla hemoglobin (vgb) gene under its native promoter, along with artificial citrate operon under constitutive tac promoter, was constructed and transformed into E. hormaechei DHRSS. This transformant secreted 9 mM citric acid under microaerobic conditions and released 1.0 mM P. Thus, incorporation of citrate operon along with vgb gene improves MPS ability of E. hormaechei DHRSS under buffered, microaerobic conditions mimicking rhizospheric environment.

  5. Artificial citrate operon confers mineral phosphate solubilization ability to diverse fluorescent pseudomonads.

    PubMed

    Adhikary, Hemanta; Sanghavi, Paulomi B; Macwan, Silviya R; Archana, Gattupalli; Naresh Kumar, G

    2014-01-01

    Citric acid is a strong acid with good cation chelating ability and can be very efficient in solubilizing mineral phosphates. Only a few phosphate solubilizing bacteria and fungi are known to secrete citric acids. In this work, we incorporated artificial citrate operon containing NADH insensitive citrate synthase (gltA1) and citrate transporter (citC) genes into the genome of six-plant growth promoting P. fluorescens strains viz., PfO-1, Pf5, CHAO1, P109, ATCC13525 and Fp315 using MiniTn7 transposon gene delivery system. Comprehensive biochemical characterization of the genomic integrants and their comparison with plasmid transformants of the same operon in M9 minimal medium reveals the highest amount of ∼7.6±0.41 mM citric and 29.95±2.8 mM gluconic acid secretion along with ∼43.2±3.24 mM intracellular citrate without affecting the growth of these P. fluorescens strains. All genomic integrants showed enhanced citric and gluconic acid secretion on Tris-Cl rock phosphate (TRP) buffered medium, which was sufficient to release 200-1000 µM Pi in TRP medium. This study demonstrates that MPS ability could be achieved in natural fluorescent pseudomonads by incorporation of artificial citrate operon not only as plasmid but also by genomic integration.

  6. Polyethyleneimine phosphate and citrate systems act like pseudo polyampholytes as a starting method to isolate pepsin.

    PubMed

    Manzur, Alejandra; Spelzini, Darío; Farruggia, Beatriz; Romanini, Diana; Picó, Guillermo

    2007-12-01

    The aqueous solution behaviour of polyethyleneimine (a cationic synthetic polymer) in the presence of anions (such as citrate and phosphate) was studied by means of turbidimetry. The variation of the absorbance at 420 nm of dilute mixture with pH, the polymer concentration and the ionic strength were examined. The mixture of polyethyleneinine citrate or polyethyleneinine phosphate behaves as a pseudo polyampholyte with an isoelectric point of 5.5 and 6.2 for phosphate and citrate respectively and a precipitation pH range between 3.5 and 8.0. Pepsin was completely precipitated with the polymer anion complex within this pH interval. Citrate showed a better precipitation effect than phosphate did. The precipitate was reversibly dissolved in NaCl (for concentrations higher than 0.2 M) and pepsin kept its biological activity. Studies of pepsin thermal stability (by differential scanning calorimetry) revealed that the polyethyleneimine presence increased the enzyme denaturation temperature. The circular dichroism spectrum of pepsin showed a non-significant loss of secondary and tertiary enzyme structure by the polyethyleneimine. However, the polymer presence increased the biological activity of pepsin.

  7. Does Potassium Citrate Medical Therapy Increase the Risk of Calcium Phosphate Stone Formation?

    NASA Astrophysics Data System (ADS)

    Leitao, Victor; Haleblian, George E.; Robinson, Marnie R.; Pierre, Sean A.; Sur, Roger L.; Preminger, Glenn M.

    2007-04-01

    Potassium citrate has been extensively used in the treatment of recurrent nephrolithiasis. Recent evidence suggests that it may contribute to increasing urinary pH and, as such, increase the risk of calcium phosphate stone formation. We performed a retrospective review of our patients to further investigate this phenomenon.

  8. Plasma membrane H-ATPase-dependent citrate exudation from cluster roots of phosphate-deficient white lupin.

    PubMed

    Tomasi, Nicola; Kretzschmar, Tobias; Espen, Luca; Weisskopf, Laure; Fuglsang, Anja Thoe; Palmgren, Michael Gjedde; Neumann, Günter; Varanini, Zeno; Pinton, Roberto; Martinoia, Enrico; Cesco, Stefano

    2009-05-01

    White lupin (Lupinus albus L.) is able to grow on soils with sparingly available phosphate (P) by producing specialized structures called cluster roots. To mobilize sparingly soluble P forms in soils, cluster roots release substantial amounts of carboxylates and concomitantly acidify the rhizosphere. The relationship between acidification and carboxylate exudation is still largely unknown. In the present work, we studied the linkage between organic acids (malate and citrate) and proton exudations in cluster roots of P-deficient white lupin. After the illumination started, citrate exudation increased transiently and reached a maximum after 5 h. This effect was accompanied by a strong acidification of the external medium and alkalinization of the cytosol, as evidenced by in vivo nuclear magnetic resonance (NMR) analysis. Fusicoccin, an activator of the plasma membrane (PM) H+-ATPase, stimulated citrate exudation, whereas vanadate, an inhibitor of the H+-ATPase, reduced citrate exudation. The burst of citrate exudation was associated with an increase in expression of the LHA1 PM H+-ATPase gene, an increased amount of H+-ATPase protein, a shift in pH optimum of the enzyme and post-translational modification of an H+-ATPase protein involving binding of activating 14-3-3 protein. Taken together, our results indicate a close link in cluster roots of P-deficient white lupin between the burst of citrate exudation and PM H+-ATPase-catalysed proton efflux.

  9. Ab initio calculation of the Zn isotope effect in phosphates, citrates, and malates and applications to plants and soil.

    PubMed

    Fujii, Toshiyuki; Albarède, Francis

    2012-01-01

    Stable Zn isotopes are fractionated in roots and leaves of plants. Analyses demonstrate that the heavy Zn isotopes are enriched in the root system of plants with respect to shoots and leaves as well as the host soil, but the fractionation mechanisms remain unclear. Here we show that the origin of this isotope fractionation is due to a chemical isotope effect upon complexation by Zn malates and citrates in the aerial parts and by phosphates in the roots. We calculated the Zn isotope effect in aqueous citrates, malates, and phosphates by ab initio methods. For pH<5, the Zn isotopic compositions of the various parts of the plants are expected to be similar to those of groundwater. In the neutral to alkaline region, the calculations correctly predict that (66)Zn is enriched over (64)Zn in roots, which concentrate phosphates, with respect to leaves, which concentrate malates and citrates, by about one permil. It is proposed that Zn isotope fractionation represents a useful tracer of Zn availability and mobility in soils.

  10. Performance characteristics of an ion chromatographic method for the quantitation of citrate and phosphate in pharmaceutical solutions.

    PubMed

    Jenke, Dennis; Sadain, Salma; Nunez, Karen; Byrne, Frances

    2007-01-01

    The performance of an ion chromatographic method for measuring citrate and phosphate in pharmaceutical solutions is evaluated. Performance characteristics examined include accuracy, precision, specificity, response linearity, robustness, and the ability to meet system suitability criteria. In general, the method is found to be robust within reasonable deviations from its specified operating conditions. Analytical accuracy is typically 100 +/- 3%, and short-term precision is not more than 1.5% relative standard deviation. The instrument response is linear over a range of 50% to 150% of the standard preparation target concentrations (12 mg/L for phosphate and 20 mg/L for citrate), and the results obtained using a single-point standard versus a calibration curve are essentially equivalent. A small analytical bias is observed and ascribed to the relative purity of the differing salts, used as raw materials in tested finished products and as reference standards in the analytical method. The assay is specific in that no phosphate or citrate peaks are observed in a variety of method-related solutions and matrix blanks (with and without autoclaving). The assay with manual preparation of the eluents is sensitive to the composition of the eluent in the sense that the eluent must be effectively degassed and protected from CO(2) ingress during use. In order for the assay to perform effectively, extensive system equilibration and conditioning is required. However, a properly conditioned and equilibrated system can be used to test a number of samples via chromatographic runs that include many (> 50) injections.

  11. Optimization and validation of a rapid method to determine citrate and inorganic phosphate in milk by capillary electrophoresis.

    PubMed

    Izco, J M; Tormo, M; Harris, A; Tong, P S; Jimenez-Flores, R

    2003-01-01

    Quantification of phosphate and citrate compounds is very important because their distribution between soluble and colloidal phases of milk and their interactions with milk proteins influence the stability and some functional properties of dairy products. The aim of this work was to optimize and validate a capillary electrophoresis method for the rapid determination of these compounds in milk. Various parameters affecting analysis have been optimized, including type, composition, and pH of the electrolyte, and sample extraction. Ethanol, acetonitrile, sulfuric acid, water at 50 degrees C or at room temperature were tested as sample buffers (SB). Water at room temperature yielded the best overall results and was chosen for further validation. The extraction time was checked and could be shortened to less than 1 min. Also, sample preparation was simplified to pipet 12 microl of milk into 1 ml of water containing 20 ppm of tartaric acid as an internal standard. The linearity of the method was excellent (R2 > 0.999) with CV values of response factors <3%. The detection limits for phosphate and citrate were 5.1 and 2.4 nM, respectively. The accuracy of the method was calculated for each compound (103.2 and 100.3%). In addition, citrate and phosphate content of several commercial milk samples were analyzed by this method, and the results deviated less than 5% from values obtained when analyzing the samples by official methods. To study the versatility of the technique, other dairy productssuch as cream cheese, yogurt, or Cheddar cheese were analyzed and accuracy was similar to milk in all products tested. The procedure is rapid and offers a very fast and simple sample preparation. Once the sample has arrived at the laboratory, less than 5 min (including handling, preparation, running, integration, and quantification) are necessary to determine the concentration of citric acid and inorganic phosphate. Because of the speed and accuracy of this method, it is promising as an

  12. Citrate bridges between mineral platelets in bone.

    PubMed

    Davies, Erika; Müller, Karin H; Wong, Wai Ching; Pickard, Chris J; Reid, David G; Skepper, Jeremy N; Duer, Melinda J

    2014-04-08

    We provide evidence that citrate anions bridge between mineral platelets in bone and hypothesize that their presence acts to maintain separate platelets with disordered regions between them rather than gradual transformations into larger, more ordered blocks of mineral. To assess this hypothesis, we take as a model for a citrate bridging between layers of calcium phosphate mineral a double salt octacalcium phosphate citrate (OCP-citrate). We use a combination of multinuclear solid-state NMR spectroscopy, powder X-ray diffraction, and first principles electronic structure calculations to propose a quantitative structure for this material, in which citrate anions reside in a hydrated layer, bridging between apatitic layers. To assess the relevance of such a structure in native bone mineral, we present for the first time, to our knowledge, (17)O NMR data on bone and compare them with (17)O NMR data for OCP-citrate and other calcium phosphate minerals relevant to bone. The proposed structural model that we deduce from this work for bone mineral is a layered structure with thin apatitic platelets sandwiched between OCP-citrate-like hydrated layers. Such a structure can explain a number of known structural features of bone mineral: the thin, plate-like morphology of mature bone mineral crystals, the presence of significant quantities of strongly bound water molecules, and the relatively high concentration of hydrogen phosphate as well as the maintenance of a disordered region between mineral platelets.

  13. The Phosphate Binder Ferric Citrate and Mineral Metabolism and Inflammatory Markers in Maintenance Dialysis Patients: Results From Prespecified Analyses of a Randomized Clinical Trial

    PubMed Central

    Van Buren, Peter N.; Lewis, Julia B.; Dwyer, Jamie P.; Greene, Tom; Middleton, John; Sika, Mohammed; Umanath, Kausik; Abraham, Josephine D.; Arfeen, Shahabul S.; Bowline, Isai G.; Chernin, Gil; Fadem, Stephen Z.; Goral, Simin; Koury, Mark; Sinsakul, Marvin V.; Weiner, Daniel E.

    2016-01-01

    Background Phosphate binders are the cornerstone of hyperphosphatemia management in dialysis patients. Ferric citrate is an iron-based oral phosphate binder that effectively lowers serum phosphorus levels. Study Design 52-week, open-label, phase 3, randomized, controlled trial for safety-profile assessment. Setting & Participants Maintenance dialysis patients with serum phosphorus levels ≥6.0 mg/dL after washout of prior phosphate binders. Intervention 2:1 randomization to ferric citrate or active control (sevelamer carbonate and/or calcium acetate). Outcomes Changes in mineral bone disease, protein-energy wasting/inflammation, and occurrence of adverse events after 1 year. Measurements Serum calcium, intact parathyroid hormone, phosphorus, aluminum, white blood cell count, percentage of lymphocytes, serum urea nitrogen, and bicarbonate. Results There were 292 participants randomly assigned to ferric citrate, and 149, to active control. Groups were well matched. For mean changes from baseline, phosphorus levels decreased similarly in the ferric citrate and active control groups (−2.04 ± 1.99 [SD] vs −2.18 ± 2.25 mg/dL, respectively; P = 0.9); serum calcium levels increased similarly in the ferric citrate and active control groups (0.22 ± 0.90 vs 0.31 ± 0.95 mg/dL; P = 0.2). Hypercalcemia occurred in 4 participants receiving calcium acetate. Parathyroid hormone levels decreased similarly in the ferric citrate and active control groups (−167.1 ± 399.8 vs −152.7 ± 392.1 pg/mL; P = 0.8). Serum albumin, bicarbonate, serum urea nitrogen, white blood cell count and percentage of lymphocytes, and aluminum values were similar between ferric citrate and active control. Total and low-density lipoprotein cholesterol levels were lower in participants receiving sevelamer than those receiving ferric citrate and calcium acetate. Fewer participants randomly assigned to ferric citrate had serious adverse events compared with active control. Limitations Open

  14. Role of ligands in accumulation and fractionation of rare Earth elements in plants: examples of phosphate and citrate.

    PubMed

    Ding, Shiming; Liang, Tao; Zhang, Chaosheng; Yan, Juncai; Zhang, Zili; Sun, Qin

    2005-10-01

    Few studies have been carried out on the effects of ligands on rare earth element (REE) bioaccumulation processes. In this study, the effects of phosphate (Pi, an inorganic ligand) and citrate (an organic ligand) on accumulation and fractionation of REEs in wheat were investigated using aqueous culture with extraneous mixed REEs (MRE). The results show that initial Pi solution culture at various levels followed by exposure to a fixed-MRE solution did not significantly change the total concentrations of REEs (SigmaREE) in roots, whereas the SigmaREE in leaves dramatically decreased with increasing levels of Pi applied. Simultaneous culture of wheat with mixture of MRE and citrate solutions caused obvious decreases of the SigmaREE in both roots and leaves. Compared with MRE, significant fractionations of REEs were found in wheat organs when no ligand was applied. Notable middle REE (MREE) enrichment and M-type tetrad effect were observed in the roots, and heavy REE (HREE) enrichment and W-type tetrad effect existed in the leaves. Pi treatments did not significantly affect the fractionations of REEs in the roots, but enrichment of HREEs in the leaves slightly increased at the highest level of Pi applied. Fractionations of REEs in both roots and leaves decreased with increasing levels of citrate applied; at higher levels of citrate (> or =150 microM), no above fractionation features were observed in wheat, but light REE (LREE) enrichment existed in the roots and leaves. The results indicate that ligands might play important roles in accumulation and fractionation of REEs during bioaccumulation processes.

  15. Effect of phosphate buffer on aggregation kinetics of citrate-coated silver nanoparticles induced by monovalent and divalent electrolytes.

    PubMed

    Afshinnia, K; Baalousha, M

    2017-03-01

    The attachment efficiency (α) is an important parameter that can be used to characterize nanoparticle (NPs) aggregation behavior and has been a topic of discussion of several papers in the past few years. The importance of α is because it is one of the key parameters that can be used to model NP environmental fate and behavior. This study uses UV-vis and laser Doppler electrophoresis to monitor the aggregation behavior of citrate-coated silver nanoparticles (cit-AgNPs) induced by Na(+) and Ca(2+) as counter ions in the presence and absence of Suwannee River fulvic acid (SRFA) as a surrogate of natural organic matter and different concentrations of phosphate buffer (0-1mM). Results demonstrate that phosphate buffer, which serves to maintain pH nearly constant over the course of a reaction, is an important determinant of NP aggregation behavior. Increasing phosphate buffer concentration results in a decrease in the critical coagulation concentrations (CCC) of cit-AgNPs to lower counter ion concentration and an increase of α at the same counter ion concentration, both in the absence and presence of SRFA. SRFA stabilizes AgNPs and increases the CCC to higher counter ion concentrations. The outcome of this study can be used to rationalize the variation in α and CCC values reported in the literature for NPs with similar physicochemical properties, where different α and CCC values are reported when different types of buffers and buffer concentrations are used in different studies.

  16. Effect of the Food Additives Sodium Citrate and Disodium Phosphate on Shiga Toxin-Producing Escherichia coli and Production of stx-Phages and Shiga toxin

    PubMed Central

    Lenzi, Lucas J.; Lucchesi, Paula M. A.; Medico, Lucía; Burgán, Julia; Krüger, Alejandra

    2016-01-01

    Induction and propagation of bacteriophages along the food production chain can represent a significant risk when bacteriophages carry genes for potent toxins. The aim of this study was to evaluate the effect of different compounds used in the food industry on the growth of Shiga toxin-producing Escherichia coli (STEC) and the production of stx-phage particles and Shiga toxin. We tested the in vitro effect of lactic acid, acetic acid, citric acid, disodium phosphate, and sodium citrate on STEC growth. A bacteriostatic effect was observed in most of treated cultures. The exceptions were those treated with sodium citrate and disodium phosphate in which similar growth curves to the untreated control were observed, but with reduced OD600 values. Evaluation of phage production by plaque-based assays showed that cultures treated with sodium citrate and disodium phosphate released phages in similar o lower levels than untreated cultures. However, semi-quantification of Stx revealed higher levels of extracellular Stx in STEC cultures treated with 2.5% sodium citrate than in untreated cultures. Our results reinforce the importance to evaluate if additives and other treatments used to decrease bacterial contamination in food induce stx-phage and Stx production. PMID:27446032

  17. Effect of the Food Additives Sodium Citrate and Disodium Phosphate on Shiga Toxin-Producing Escherichia coli and Production of stx-Phages and Shiga toxin.

    PubMed

    Lenzi, Lucas J; Lucchesi, Paula M A; Medico, Lucía; Burgán, Julia; Krüger, Alejandra

    2016-01-01

    Induction and propagation of bacteriophages along the food production chain can represent a significant risk when bacteriophages carry genes for potent toxins. The aim of this study was to evaluate the effect of different compounds used in the food industry on the growth of Shiga toxin-producing Escherichia coli (STEC) and the production of stx-phage particles and Shiga toxin. We tested the in vitro effect of lactic acid, acetic acid, citric acid, disodium phosphate, and sodium citrate on STEC growth. A bacteriostatic effect was observed in most of treated cultures. The exceptions were those treated with sodium citrate and disodium phosphate in which similar growth curves to the untreated control were observed, but with reduced OD600 values. Evaluation of phage production by plaque-based assays showed that cultures treated with sodium citrate and disodium phosphate released phages in similar o lower levels than untreated cultures. However, semi-quantification of Stx revealed higher levels of extracellular Stx in STEC cultures treated with 2.5% sodium citrate than in untreated cultures. Our results reinforce the importance to evaluate if additives and other treatments used to decrease bacterial contamination in food induce stx-phage and Stx production.

  18. A comparative randomized double-blind clinical trial of isoaminile citrate and chlophedianol hydrochloride as antitussive agents.

    PubMed

    Diwan, J; Dhand, R; Jindal, S K; Malik, S K; Sharma, P L

    1982-08-01

    The efficacy and safety of a new centrally acting antitussive agent, isoaminile citrate, was compared with that of chlophedianol hydrochloride in a double-blind, randomized interpatient study. A total of 66 patients participated, two and four patients were lost to follow-up with isoaminile and chlophedianol, respectively. In the experimentally induced cough in 12 normal human subjects, isoaminile (40 mg) was as effective as chlophedianol (20 mg), but its duration of action was somewhat longer. One subject developed allergic skin rash with chlophedianol and was withdrawn from the study. In 60 patients with cough associated with chest diseases, isoaminile (40 mg, 3 x daily) was as effective as chlophedianol (20 mg, 3 x daily) in suppressing cough as judged from the 3-h and 24-h cough counts. The increase in PEFR at day 7 of treatment was somewhat more marked with chlophedianol as compared with isoaminile. None of the drugs interfered with the expectoration process. The side effects observed were few, mild in nature, and did not require a decrease in dose or withdrawal of treatment in any of the patients. Isoaminile citrate was concluded to be an effective and relatively safe antitussive agent. Isoaminile citrate, alpha(isopropyl)-alpha-(beta-dimethylaminoproyl) phenylacetonitrile citrate, is a centrally acting antitussive agent. In animal experiments this drug was as efficacious as codeine but was devoid of any respiratory depressant effect [Krause 1958, Kuroda et al. 1971]. This controlled double-randomized interpatient study was designed to test the comparative efficacy and safety of isoaminile and chlophedianol, another centrally acting antitussive, in humans.

  19. Effects of citrate and NaCl on size, morphology, crystallinity and microstructure of calcium phosphates obtained from aqueous solutions at acidic or near-neutral pH.

    PubMed

    Mekmene, Omar; Rouillon, Thierry; Quillard, Sophie; Pilet, Paul; Bouler, Jean-Michel; Pezennec, Stéphane; Gaucheron, Frédéric

    2012-05-01

    Precipitation of calcium phosphates occurs in dairy products and depending on pH and ionic environment, several salts with different crystallinity can form. The present study aimed to investigate the effects of NaCl and citrate on the characteristics of precipitates obtained from model solutions of calcium phosphate at pH 6·70 maintained constant or left to drift. The ion speciation calculations showed that all the starting solutions were supersaturated with respect to dicalcium phosphate dihydrate (DCPD), octacalcium phosphate (OCP) and hydroxyapatite (HAP) in the order HAP>OCP>DCPD. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses of the precipitates showed that DCPD was formed at drifting pH (acidic final pH) whereas poor crystallised calcium deficient apatite was mainly formed at constant pH (6·70). Laser light scattering measurements and electron microscopy observations showed that citrate had a pronounced inhibitory effect on the crystallisation of calcium phosphates both at drifting and constant pH. This resulted in the decrease of the particle sizes and the modification of the morphology and the microstructure of the precipitates. The inhibitory effect of citrate mainly acted by the adsorption of the citrate molecules onto the surfaces of newly formed nuclei of calcium phosphate, thereby changing the morphology of the growing particles. These findings are relevant for the understanding of calcium phosphate precipitation from dairy byproducts that contain large amounts of NaCl and citrate.

  20. The yeast mitochondrial citrate transport protein: identification of the Lysine residues responsible for inhibition mediated by Pyridoxal 5'-phosphate.

    PubMed

    Remani, Sreevidya; Sun, Jiakang; Kotaria, Rusudan; Mayor, June A; Brownlee, June M; Harrison, David H T; Walters, D Eric; Kaplan, Ronald S

    2008-12-01

    The present investigation identifies the molecular basis for the well-documented inhibition of the mitochondrial inner membrane citrate transport protein (CTP) function by the lysine-selective reagent pyridoxal 5'-phosphate. Kinetic analysis indicates that PLP is a linear mixed inhibitor of the Cys-less CTP, with a predominantly competitive component. We have previously concluded that the CTP contains at least two substrate binding sites which are located at increasing depths within the substrate translocation pathway and which contain key lysine residues. In the present investigation, the roles of Lys-83 in substrate binding site one, Lys-37 and Lys-239 in substrate binding site two, and four other off-pathway lysines in conferring PLP-inhibition of transport was determined by functional characterization of seven lysine to cysteine substitution mutants. We observed that replacement of Lys-83 with cysteine resulted in a 78% loss of the PLP-mediated inhibition of CTP function. In contrast, replacement of either Lys-37 or Lys-239 with cysteine caused a modest reduction in the inhibition caused by PLP (i.e., 31% and 20% loss of inhibition, respectively). Interestingly, these losses of PLP-mediated inhibition could be rescued by covalent modification of each cysteine with MTSEA, a reagent that adds a lysine-like moiety (i.e. SCH(2)CH(2)NH(3) (+)) to the cysteine sulfhydryl group. Importantly, the replacement of non-binding site lysines (i.e., Lys-45, Lys-48, Lys-134, Lys-141) with cysteine resulted in little change in the PLP inhibition. Based upon these results, we conducted docking calculations with the CTP structural model leading to the development of a physical binding model for PLP. In combination, our data support the conclusion that PLP exerts its main inhibitory effect by binding to residues located within the two substrate binding sites of the CTP, with Lys-83 being the primary determinant of the total PLP effect since the replacement of this single lysine

  1. Phosphate-intercalated Ca-Fe-layered double hydroxides: Crystal structure, bonding character, and release kinetics of phosphate

    SciTech Connect

    Woo, Myong A.; Woo Kim, Tae; Paek, Mi-Jeong; Ha, Hyung-Wook; Choy, Jin-Ho; Hwang, Seong-Ju

    2011-01-15

    The nitrate-form of Ca-Fe-layered double hydroxide (Ca-Fe-LDH) was synthesized via co-precipitation method, and its phosphate-intercalates were prepared by ion-exchange reaction. According to X-ray diffraction analysis, the Ca-Fe-LDH-NO{sub 3}{sup -} compound and its H{sub 2}PO{sub 4}{sup -}-intercalate showed hexagonal layered structures, whereas the ion-exchange reaction with HPO{sub 4}{sup 2-} caused a frustration of the layer ordering of LDH. Fe K-edge X-ray absorption spectroscopy clearly demonstrated that the Ca-Fe-LDH lattice with trivalent iron ions was well-maintained after the ion-exchange with HPO{sub 4}{sup 2-} and H{sub 2}PO{sub 4}{sup -}. Under acidic conditions, phosphate ions were slowly released from the Ca-Fe-LDH lattice and the simultaneous release of hydroxide caused the neutralization of acidic media. Fitting analysis based on kinetic models indicated a heterogeneous diffusion process of phosphates and a distinct dependence of release rate on the charge of phosphates. This study strongly suggested that Ca-Fe-LDH is applicable as bifunctional vector for slow release of phosphate fertilizer and for the neutralization of acid soil. -- Graphical abstract: We synthesized phosphate-intercalated Ca-Fe-LDH materials that can act as bifunctional inorganic vectors for the slow release of phosphate fertilizer and also the neutralization of acid soil. Fitting analysis based on kinetic models indicated a heterogeneous diffusion process of phosphates and a distinct dependence of release rate on the charge of phosphates. Display Omitted Research Highlights: {yields} The phosphate forms of Ca-Fe-layered double hydroxide (Ca-Fe-LDH) were synthesized via co-precipitation method. The crystal structure, bonding character, and release kinetics of phosphate of the phosphate-intercalates were investigated. These Ca-Fe-LDH materials are applicable as bifunctional vector for slow release of phosphate fertilizer and for the neutralization of acid soil.

  2. Net Budgetary Impact of Ferric Citrate as a First-Line Phosphate Binder for the Treatment of Hyperphosphatemia: A Markov Microsimulation Model.

    PubMed

    Brunelli, Steven M; Sibbel, Scott P; Van Wyck, David; Sharma, Amit; Hsieh, Andrew; Chertow, Glenn M

    2017-03-01

    Ferric citrate (FC) has demonstrated efficacy as a phosphate binder and reduces the requirements for erythropoiesis-stimulating agents (ESAs) and intravenous (IV) iron in dialysis patients. We developed a net budgetary impact model to evaluate FC vs. other phosphate binders from the vantage of a large dialysis provider. We used a Markov microsimulation model to simulate mutually referential longitudinal effects between serum phosphate and phosphate binder dose; categories of these defined health states. Health states probabilistically determined treatment attendance and utilization of ESA and IV iron. We derived model inputs from a retrospective analysis of incident phosphate binder users from a large dialysis organization (January 2011-June 2013) and incorporated treatment effects of FC from a phase III trial. The model was run over a 1-year time horizon. We considered fixed costs of providing dialysis; costs of administering ESA and IV iron; and payment rates for dialysis, ESAs, and IV iron. In the base-case model, FC had a net budgetary impact (savings) of +US$213,223/year per 100 patients treated vs. standard of care. One-way sensitivity analyses showed a net budgetary impact of up to +US$316,296/year per 100 patients treated when higher hemoglobin levels observed with FC translated into a 30% additional ESA dose reduction, and up to +US$223,281/year per 100 patients treated when effects on missed treatment rates were varied. Two-way sensitivity analyses in which acquisition costs for ESA and IV iron were varied showed a net budgetary impact of +US$104,840 to +US$213,223/year per 100 patients treated. FC as a first-line phosphate binder would likely yield substantive savings vs. standard of care under current reimbursement.

  3. The control of fatty acid and triglyceride synthesis in rat epididymal adipose tissue. Roles of coenzyme A derivatives, citrate and l-glycerol 3-phosphate

    PubMed Central

    Denton, R. M.; Halperin, M. L.

    1968-01-01

    1. Methods are described for the extraction and assay of acetyl-CoA and of total acid-soluble and total acid-insoluble CoA derivatives in rat epididymal adipose tissue. 2. The concentration ranges of the CoA derivatives in fat pads incubated in vitro under various conditions were: total acid-soluble CoA, 0·20–0·59mm; total acid-insoluble CoA, 0·08–0·23mm; acetyl-CoA, 0·03–0·14mm. 3. An investigation was made of some postulated mechanisms of control of fatty acid and triglyceride synthesis in rat epididymal fat pads incubated in vitro. The concentrations of intermediates of possible regulatory significance were measured at various rates of fatty acid and triglyceride synthesis produced by the addition to the incubation medium (Krebs bicarbonate buffer containing glucose) of insulin, adrenaline, albumin, palmitate or acetate. 4. The whole-tissue concentrations of glucose 6-phosphate, l-glycerol 3-phosphate, citrate, acetyl-CoA, total acid-soluble CoA and total acid-insoluble CoA were assayed after 30 or 60min. incubation. The rates of fatty acid and triglyceride synthesis, calculated from the incorporation of [U-14C]glucose into fatty acids and glyceride glycerol respectively, and the rates of glucose uptake, lactate plus pyruvate output and glycerol output were measured over a 60min. incubation. 5. The rate of triglyceride synthesis could not be correlated with the concentrations of either l-glycerol 3-phosphate or long-chain fatty acyl-CoA (measured as total acid-insoluble CoA). Factor(s) other than the whole-tissue concentrations of these recognized precursors appear to be involved in the determination of the rate of triglyceride synthesis. 6. No relationship was found between the rate of fatty acid synthesis and the whole-tissue concentrations of the intermediates, citrate or acetyl-CoA, or with the two proposed effectors of acetyl-CoA carboxylase, citrate (as activator) or long-chain fatty acyl-CoA (as inhibitor). The control of fatty acid synthesis

  4. Hydration of the phosphate group in double-helical DNA.

    PubMed Central

    Schneider, B; Patel, K; Berman, H M

    1998-01-01

    Water distributions around phosphate groups in 59 B-, A-, and Z-DNA crystal structures were analyzed. It is shown that the waters are concentrated in six hydration sites per phosphate and that the positions and occupancies of these sites are dependent on the conformation and type of nucleotide. The patterns of hydration that are characteristic of the backbone of the three DNA helical types can be attributed in part to the interactions of these hydration sites. PMID:9788937

  5. Sodium citrate and potassium phosphate as alternative adsorption buffers in hydrophobic and aromatic thiophilic chromatographic purification of plasmid DNA from neutralized lysate.

    PubMed

    Bonturi, Nemailla; Radke, Vanessa Soraia Cortez Oliveira; Bueno, Sônia Maria Alves; Freitas, Sindélia; Azzoni, Adriano Rodrigues; Miranda, Everson Alves

    2013-03-01

    The number of studies on gene therapy using plasmid vectors (pDNA) has increased in recent years. As a result, the demand for preparations of pDNA in compliance with recommendations of regulatory agencies (EMEA, FDA) has also increased. Plasmid DNA is often obtained through fermentation of transformed Escherichia coli and purification by a series of unit operations, including chromatography. Hydrophobic interaction chromatography (HIC) and thiophilic aromatic chromatography (TAC), both using ammonium sulfate buffers, are commonly employed with success. This work was aimed at studying the feasibility of utilizing alternative salts in the purification of pDNA from neutralized lysate with phenyl-agarose (HIC) and mercaptopyrimidine-agarose (TAC) adsorbents. Their selectivity toward sc pDNA was evaluated through adsorption studies using 1.5 mol/L sodium citrate and 2.0 mol/L potassium phosphate as adsorption buffers. Chromatography with mercaptopyrimidine-agarose adsorbent and 1.5 mol/L sodium citrate was able to recover 91.1% of the pDNA with over 99.0% removal of gDNA and endotoxin. This represents a potential alternative for the primary recovery of sc pDNA. However, the most promising result was obtained using 2.0 mol/L potassium phosphate buffer and a mercaptopyrimidine-agarose column. In a single chromatographic step, this latter buffer/adsorbent system recovered 68.5% of the pDNA with 98.8% purity in accordance with the recommendations of regulatory agencies with regard to RNA and endotoxin impurity.

  6. Phosphate-intercalated Ca-Fe-layered double hydroxides: Crystal structure, bonding character, and release kinetics of phosphate

    NASA Astrophysics Data System (ADS)

    Woo, Myong A.; Woo Kim, Tae; Paek, Mi-Jeong; Ha, Hyung-Wook; Choy, Jin-Ho; Hwang, Seong-Ju

    2011-01-01

    The nitrate-form of Ca-Fe-layered double hydroxide (Ca-Fe-LDH) was synthesized via co-precipitation method, and its phosphate-intercalates were prepared by ion-exchange reaction. According to X-ray diffraction analysis, the Ca-Fe-LDH-NO 3- compound and its H 2PO 4--intercalate showed hexagonal layered structures, whereas the ion-exchange reaction with HPO 42- caused a frustration of the layer ordering of LDH. Fe K-edge X-ray absorption spectroscopy clearly demonstrated that the Ca-Fe-LDH lattice with trivalent iron ions was well-maintained after the ion-exchange with HPO 42- and H 2PO 4-. Under acidic conditions, phosphate ions were slowly released from the Ca-Fe-LDH lattice and the simultaneous release of hydroxide caused the neutralization of acidic media. Fitting analysis based on kinetic models indicated a heterogeneous diffusion process of phosphates and a distinct dependence of release rate on the charge of phosphates. This study strongly suggested that Ca-Fe-LDH is applicable as bifunctional vector for slow release of phosphate fertilizer and for the neutralization of acid soil.

  7. The influence of citrate and phosphate on the Mancini single radial immunodiffusion technique and suggested improvements for the determination of urinary albumin.

    PubMed

    Gustafsson, J E; Uzqueda, H R

    1978-12-15

    When adapting the immediate bromcresol green method for urinary albumin determination a correlation study with the Mancini single radial immunodiffusion (SRID) method was performed. This study showed large disparities between the two methods, SRID giving the higher results. The unsuitability of the currently used SRID methods is demonstrated and improvements to the method are suggested. Known amounts of albumin were added to urine samples as well as to a "synthetic urine", both giving falsely elevated results with the SRID method. On investigating the different components of the "synthetic urine", it was found that the disparities were due to the influence of citrate and phosphate. On addition of citric acid or phosphate to the dilution buffer and/or the gel buffer, the results of the SRID method agreed with those of other methods and with the expected values. The findings presented in this paper can probably be extended to other immunological methods too since it seems to be the antigen-antibody reaction which is affected.

  8. Sildenafil citrate for the prevention of high altitude hypoxic pulmonary hypertension: double blind, randomized, placebo-controlled trial.

    PubMed

    Bates, Matthew G D; Thompson, A A Roger; Baillie, J Kenneth; Sutherland, Andrew I; Irving, John B; Hirani, Nikhil; Webb, David J

    2011-01-01

    Exaggerated hypoxic pulmonary vasoconstriction is a key factor in the development of high altitude pulmonary edema (HAPE). Due to its effectiveness as a pulmonary vasodilator, sildenafil has been proposed as a prophylactic agent against HAPE. By conducting a parallel-group double blind, randomized, placebo-controlled trial, we investigated the effect of chronic sildenafil administration on pulmonary artery systolic pressure (PASP) and symptoms of acute mountain sickness (AMS) during acclimatization to high altitude. Sixty-two healthy lowland volunteers (36 male; median age 21 years, range 18 to 31) on the Apex 2 research expedition were flown to La Paz, Bolivia (3650 m), and after 4-5 days acclimatization ascended over 90 min to 5200 m. The treatment group (n=20) received 50 mg sildenafil citrate three times daily. PASP was recorded by echocardiography at sea level and within 6 h, 3 days, and 1 week at 5200 m. AMS was assessed daily using the Lake Louise Consensus symptom score. On intention-to-treat analysis, there was no significant difference in PASP at 5200 m between sildenafil and placebo groups. Median AMS score on Day 2 at 5200 m was significantly higher in the sildenafil group (placebo 4.0, sildenafil 6.5; p=0.004) but there was no difference in prevalence of AMS between groups. Sildenafil administration did not affect PASP in healthy lowland subjects at 5200 m but AMS was significantly more severe on Day 2 at 5200 m with sildenafil. Our data do not support routine prophylactic use of sildenafil to reduce PASP at high altitude in healthy subjects with no history of HAPE. TRIALS REGISTRATION NUMBER: NCT00627965.

  9. Citrate Metabolism by Pediococcus halophilus

    PubMed Central

    Kanbe, Chiyuki; Uchida, Kinji

    1987-01-01

    Several strains of non-citrate-metabolizing Pediococcus halophilus have previously been isolated from soy sauce mash or moromi. The factors controlling the metabolism of citrate in soy pediococci were studied. All the soy pediococcal strains tested which failed to decompose citrate did not possess citrate lyase [citrate (pro-3S)-lyase; EC 4.1.3.6] activity. In P. halophilus, citrate lyase was an inducible enzyme, and the optimum pH for activity was 7.0. The metabolism of citrate in P. halophilus was different from that observed in lactic streptococci. The main products from citrate were acetate and formate, and this bacterium produced no acetoin or diacetyl. Formate production from citrate was greatly reduced in the presence of glucose. P. halophilus 7117 (Cit+) was proved to contain citrate lyase, pyruvate formate-lyase (EC 2.3.1.54) phosphotransacetylase (phosphate acetyltransferase; EC 2.3.1.8), and acetate kinase (EC 2.7.2.1), i.e., all the enzymes necessary to convert citrate to acetate and formate. PMID:16347358

  10. Experiences with Continuous Venovenous Hemofiltration using 18mmol/L predilution Citrate anticoagulation and a Phosphate Containing Replacement Solution

    PubMed Central

    Jeffrey, Yuen Henry; Hoi-Ping, Shum; Kit Hung, Anne Leung; Chung-Ling, Lam; Wing-Wa, Yan; King-Yiu, Lai

    2017-01-01

    Context: Regional citrate anticoagulation for continuous renal replacement therapy is associated with a longer filter-life, less bleeding events and improved mortality. Problems associated with using Prismocitrate 10/2 solution in continuous renal replacement therapy, include hypomagnesemia, hypophosphatemia and the need for additional bicarbonate infusion. Aims: This study uses the new Prismocitrate 18/0 solution for improved buffer balance and Phoxilium solution for a more favourable electrolyte profile. Settings and Design: A retrospective analysis of patients who underwent continuous venovenous hemofiltration (CVVH) using Prismocitrate 18/0 and Phoxilium in our 21-bed ICU was conducted from March to July 2014. Methods and Material: Continuous venovenous hemofiltration (CVVH) was performed at fixed rate by using Prismocitrate 18/0 predilution at 1250 ml/hour, a blood flow rate of 110 ml/min and post-replacement with Phoxilium at 1250 ml/hr. CVVH was run for 72 h or until filter clotting, transportation, or achievement of the clinical target. Statistical Analysis Used: The results were displayed as the median with the interquartile range (IQR). The trend in pH, electrolytes, and base excess are shown using a standard box plot. All analyses were performed by the Statistical Package for Social Science for Windows, version 17 (SPSS, Chicago, IL, USA). Results: Forty-five CVVH episodes were analysed. The median circuit lifetime was 44 h (interquartile range, IQR 29-55). Metabolic alkalosis, hypophosphatemia and hypomagnesemia occurred in 8.3%, 3.5% and 40.2% of the blood samples, respectively. No patient developed hypokalemia or citrate toxicity. Conclusions: This new CVVH regime is safe and easy to administer for critically ill patients. PMID:28197045

  11. Direct observation of grafting interlayer phosphate in Mg/Al layered double hydroxides

    SciTech Connect

    Shimamura, Akihiro; Kanezaki, Eiji; Jones, Mark I.; Metson, James B.

    2012-02-15

    The grafting of interlayer phosphate in synthetic Mg/Al layered double hydroxides with interlayer hydrogen phosphate (LDH-HPO{sub 4}) has been studied by XRD, TG/DTA, FT-IR, XPS and XANES. The basal spacing of crystalline LDH-HPO{sub 4} decreases in two stages with increasing temperature, from 1.06 nm to 0.82 nm at 333 K in the first transition, and to 0.722 nm at 453 K in the second. The first stage occurs due to the loss of interlayer water and rearrangement of the interlayer HPO{sub 4}{sup 2-}. In the second transition, the interlayer phosphate is grafted to the layer by the formation of direct bonding to metal cations in the layer, accompanied by a change in polytype of the crystalline structure. The grafted phosphate becomes immobilized and cannot be removed by anion-exchange with 1-octanesulfonate. The LDH is amorphous at 743 K but decomposes to Mg{sub 3}(PO{sub 4}){sub 2}, AlPO{sub 4}, MgO and MgAl{sub 2}O{sub 4} after heated to 1273 K. - Graphical abstract: The cross section of the synthetic Mg, Al layered double hydroxides in Phase 1, with interlayer hydrogen phosphate Phase 2, and with grafted phosphate, Phase 3. Highlights: Black-Right-Pointing-Pointer The grafting of hydrogen phosphate intercalated Mg/Al-LDH has been studied. Black-Right-Pointing-Pointer The basal spacing of crystalline LDH-HPO{sub 4} decreases in two stages with increasing temperature. Black-Right-Pointing-Pointer The first decrease is due to loss of interlayer water, the second is attributed to phosphate grafting. Black-Right-Pointing-Pointer The grafted interlayer phosphate becomes immobilized and cannot be removed by anion-exchange.

  12. Low-field magnetoresistance up to 400 K in double perovskite Sr{sub 2}FeMoO{sub 6} synthesized by a citrate route

    SciTech Connect

    Harnagea, L.; Jurca, B.; Berthet, P.

    2014-03-15

    A wet-chemistry technique, namely the citrate route, has been used to prepare high-quality polycrystalline samples of double perovskite Sr{sub 2}FeMoO{sub 6}. We report on the evolution of magnetic and magnetoresistive properties of the synthesized samples as a function of three parameters (i) the pH of the starting solution, (ii) the decomposition temperature of the citrate precursors and (iii) the sintering conditions. The low-field magnetoresistance (LFMR) value of our best samples is as high as 5% at room temperature for an applied magnetic field of 1 kOe. Additionally, the distinguishing feature of these samples is the persistence of LFMR, with a reasonably large value, up to 400 K which is a crucial parameter for any practical application. Our study indicates that the enhancement of LFMR observed is due to a good compromise between the grain size distribution and their magnetic polarization. -- Graphical abstract: The microstructure (left panel) and corresponding low-field magnetoresistance of one of the Sr{sub 2}FeMoO{sub 6} samples synthesized in the course of this work. Highlights: • Samples of Sr{sub 2}FeMoO{sub 6} are prepared using a citrate route under varying conditions. • Magnetoresistive properties are improved and optimized. • Low-field magnetoresitence values as large as 5% at 300 K/1 kOe are reported. • Persistence of low-field magnetoresistance up to 400 K.

  13. Phosphate recovery from wastewater using engineered superparamagnetic particles modified with layered double hydroxide ion exchangers.

    PubMed

    Drenkova-Tuhtan, Asya; Mandel, Karl; Paulus, Anja; Meyer, Carsten; Hutter, Frank; Gellermann, Carsten; Sextl, Gerhard; Franzreb, Matthias; Steinmetz, Heidrun

    2013-10-01

    An innovative nanocomposite material is proposed for phosphate recovery from wastewater using magnetic assistance. Superparamagnetic microparticles modified with layered double hydroxide (LDH) ion exchangers of various compositions act as phosphate adsorbers. Magnetic separation and chemical regeneration of the particles allows their reuse, leading to the successful recovery of phosphate. Based upon the preliminary screening of different LDH ion exchanger modifications for phosphate selectivity and uptake capacity, MgFe-Zr LDH coated magnetic particles were chosen for further characterization and application. The adsorption kinetics of phosphate from municipal wastewater was studied in dependence with particle concentration, contact time and pH. Adsorption isotherms were then determined for the selected particle system. Recovery of phosphate and regeneration of the particles was examined via testing a variety of desorption solutions. Reusability of the particles was demonstrated for 15 adsorption/desorption cycles. Adsorption in the range of 75-97% was achieved in each cycle after 1 h contact time. Phosphate recovery and enrichment was possible through repetitive application of the desorption solution. Finally, a pilot scale experiment was carried out by treating 125 L of wastewater with the particles in five subsequent 25 L batches. Solid-liquid separation on this scale was carried out with a high-gradient magnetic filter (HGMF).

  14. Migration from plasticized films into foods. 3. Migration of phthalate, sebacate, citrate and phosphate esters from films used for retail food packaging.

    PubMed

    Castle, L; Mercer, A J; Startin, J R; Gilbert, J

    1988-01-01

    A UK survey of plasticizer levels in retail foods (73 samples) wrapped in plasticized films or materials with plasticized coatings has been carried out. A wide range of different food-types packaged in vinylidene chloride copolymers (PVDC), nitrocellulose-coated regenerated cellulose film (RCF) and cellulose acetate were purchased from retail and 'take-away' outlets. Plasticizers found in these films were dibutyl sebacate (DBS) and acetyl tributyl citrate (ATBC) in PVDC, dibutyl phthalate (DBP), dicyclohexyl phthalate (DCHP), butylbenzyl phthalate (BBP), and diphenyl 2-ethylhexyl phosphate (DPOP) in RCF coatings, and diethyl phthlate (DEP) in cellulose acetate. Foodstuffs analysed included cheese, pate, chocolate and confectionery products, meat pies, cake, quiches and sandwiches. Analysis was by stable isotope dilution GC/MS for DBP, DCHP and DEP, GC/MS (selected ion monitoring) for BBP and DPOP, and GC with flame ionization detection for DBS and ATBC, but with mass spectrometric confirmation. Levels of plasticizers found in foods were in the following ranges: ATBC in cheese, 2-8 mg/kg; DBS in processed cheese and cooked meats, 76-137 mg/kg; 76-137 mg/kg; DBP, DCHP, BBP, and DPOP found individually or in combination in confectionery, meat pies, cake and sandwiches, total levels from 0.5 to 53 mg/kg; and DEP in quiches, 2-4 mg/kg.

  15. Gender and chronological age affect erythrocyte membrane oxidative indices in citrate phosphate dextrose adenine-formula 1 (CPDA-1) blood bank storage condition.

    PubMed

    Erman, Hayriye; Aksu, Uğur; Belce, Ahmet; Atukeren, Pınar; Uzun, Duygu; Cebe, Tamer; Kansu, Ahmet D; Gelişgen, Remisa; Uslu, Ezel; Aydın, Seval; Çakatay, Ufuk

    2016-07-01

    It is well known that in vitro storage lesions lead to membrane dysfunction and decreased number of functional erythrocytes. As erythrocytes get older, in storage media as well as in peripheral circulation, they undergo a variety of biochemical changes. In our study, the erythrocytes with different age groups in citrate phosphate dextrose adenine-formula 1 (CPDA-1) storage solution were used in order to investigate the possible effect of gender factor on oxidative damage. Oxidative damage biomarkers in erythrocyte membranes such as ferric reducing antioxidant power, pro-oxidant-antioxidant balance, protein-bound advance glycation end products, and sialic acid were analyzed. Current study reveals that change in membrane redox status during blood-bank storage condition also depends on both gender depended homeostatic factors and the presence of CPDA-1. During the storage period in CPDA-1, erythrocytes from the male donors are mostly affected by free radical-mediated oxidative stress but erythrocytes obtained from females are severely affected by glyoxidative stress.

  16. Pathways of phosphate uptake from aqueous solution by ZnAl layered double hydroxides.

    PubMed

    Cheng, X; Wang, Y; Sun, Z; Sun, D; Wang, A

    2013-01-01

    ZnAl layered double hydroxides (LDHs) were prepared by urea hydrolysis-based coprecipitation for removing phosphate from aqueous solutions. The chemical formula of the product was determined as Zn5.54Al3.02(OH)8.73(CO3)0.57Cl5.66·7.84H2O. Chloride ion was the major interlayer anion of the ZnAl LDHs. Adsorption of phosphate onto the ZnAl sorbent over the entire study period was not in close agreement with pseudo-first-order or pseudo-second-order models. The adsorption can be divided into two steps. A fast adsorption was observed during the first 10 h with a marked increase in the concentration of Cl(-) in the bulk solution. This indicated that the adsorption of phosphate was largely attributed to the ion exchange between phosphate and the interlayer Cl(-). A second fast adsorption of phosphate occurred after 10 h. During this period, the pH increased slowly, whereas the Cl(-) concentration was stable. The uptake of phosphate was likely attributed to OH(-)-H2PO4(-)/HPO4(2-) ion exchange as well as surface adsorption/complexation. Acidic conditions favored adsorption of phosphate by ZnAl LDHs, which is consistent with the pH increases during the adsorption. Coexisting anions, e.g., SO4(2-) and CO3(2-), are competitive ions for the adsorption of phosphate. The results verify the contribution of ion exchange and surface adsorption/complexation in the removal of phosphate by ZnAl LDHs.

  17. The metabolic fate of the products of citrate cleavage. Adenosine triphosphate citrate lyase and nicotinamide–adenine dinucleotide phosphate-linked malate dehydrogenase in foetal and adult liver from ruminants and non-ruminants

    PubMed Central

    Hanson, R. W.; Ballard, F. J.

    1968-01-01

    1. Foetal rat liver slices incorporate the C-3 of aspartate and C-2 of glutamate into fatty acids at rates equal to those observed with adult rat liver slices. Incorporation of either of these labelled carbon atoms into fatty acids would require a functioning citrate-cleavage pathway which consists of the enzymes ATP–citrate lyase, NAD–malate dehydrogenase and NADP–malate dehydrogenase. However, NADP–malate dehydrogenase is present in foetal rat liver at only 5% of the activity detectable in adult rat liver. 2. From these findings and the effect of cofactors on the formation of 14CO2 from [1,5-14C2]citrate in liver supernatant fractions (100000g), it is suggested that NADP–malate dehydrogenase limits the citrate-cleavage sequence. 3. Measurement of the citrate-cleavage pathway by incorporation studies with [3-14C]aspartate and [U-14C]glucose and by determining the activities of ATP–citrate lyase and NADP–malate dehydrogenase have shown that this sequence of reactions is present in the liver of the bovine foetus but not in the adult. However, C-2 of glutamate is not incorporated into fatty acids or non-saponifiable lipid by bovine liver slices. This finding as well as those presented above for the adult and foetal rat liver are interpreted on the basis of a competition between phosphoenolpyruvate carboxykinase and NAD–malate dehydrogenase for oxaloacetate produced by the cleavage of citrate in the cytosol. PMID:4386407

  18. Metal-catalyzed double migratory cascade reactions of propargylic esters and phosphates.

    PubMed

    Kazem Shiroodi, Roohollah; Gevorgyan, Vladimir

    2013-06-21

    Propargylic esters and phosphates are easily accessible substrates, which exhibit rich and tunable reactivities in the presence of transition metal catalysts. π-Acidic metals, mostly gold and platinum salts, activate these substrates for an initial 1,2- or 1,3-acyloxy and phosphatyloxy migration process to form reactive intermediates. These intermediates are able to undergo further cascade reactions leading to a variety of diverse structures. This tutorial review systematically introduces the double migratory reactions of propargylic esters and phosphates as a novel synthetic method, in which further cascade reaction of the reactive intermediate is accompanied by a second migration of a different group, thus offering a rapid route to a wide range of functionalized products. The serendipitous observations, as well as designed approaches involving the double migratory cascade reactions, will be discussed with emphasis placed on the mechanistic aspects and the synthetic utilities of the obtained products.

  19. [Hemoglobin Woodville associated with double point mutation in the gene of glucose-6-phosphate dehydrogenase].

    PubMed

    Mansini, Adrián P; Fernández, Diego A; Aguirre, Fernando M; Pepe, Carolina; Milanesio, Berenice; Chaves, Alejandro; Eandi Eberle, Silvia; Feliú Torres, Aurora

    2015-01-01

    The co-inheritance of erythrocyte defects, hemoglobinopathies, enzymopathies, and membranopathies is not an unusual event. For the diagnosis, a laboratory strategy, including screening and confirmatory tests, additional to molecular characterization, was designed. As the result of this approach, a 24-year-old man carrying a hemoglobinopathy (Hemoglobin Woodville) and an enzymopathy (glucose-6-phosphate dehydrogenase deficiency) was identified. In the heterozygous state hemoglobin Woodville, is asymptomatic, and homozygous or double heterozygous individuals have not been reported thus far. On the other hand, previously described double point mutation in the gene for glucose-6-phosphate dehydrogenase c. [202G>A; 376A>G], p. [Val 68Met; Asn126Asp], causes hemolysis of varying severity after food or drug intake or infections. This case highlights the importance of the methodology carried out for the diagnosis, treatment, and proper genetic counseling.

  20. Properties of Ce-activated alkali-lutetium double phosphate scintillators

    SciTech Connect

    Wiśniewski, D.; Wojtowicz, A. J.; Boatner, Lynn A

    2010-01-01

    The scintillation properties of Ce-activated alkali-lutetium double phosphate single crystals that vary with the alkali ion type and activation level are summarized and compared. The materials investigated here have been identified as fast and efficient scintillators for the detection of x-ray and radiation, and in case of Li3Lu(PO4)2:Ce, for thermal neutron detection as well.

  1. Phosphate adsorption from sewage sludge filtrate using zinc-aluminum layered double hydroxides.

    PubMed

    Cheng, Xiang; Huang, Xinrui; Wang, Xingzu; Zhao, Bingqing; Chen, Aiyan; Sun, Dezhi

    2009-09-30

    A series of layered double hydroxides (LDHs) with different metal cations were synthesized to remove phosphate in waste sludge filtrate from a municipal wastewater treatment plant for phosphorus recovery and to help control eutrophication. The highest phosphate adsorption capacity was obtained by using Zn-Al-2-300, that is LDHs with Zn/Al molar ratio of 2 and calcined at 300 degrees C for 4h. Circumneutral and mildly alkaline waters appeared suitable for the possible application of Zn-Al LDHs due to the amphoteric nature of aluminum hydroxide. Phosphate adsorption from the sludge filtrate by the LDHs followed pseudo-second-order kinetics, and the adsorption capacity at equilibrium was determined to be approximately 50 mg P/g. Adsorption isotherms showed that phosphate uptake in this study was an endothermic process and had a good fit with a Langmuir-type model. The absorbed phosphate can be effectively desorbed (more than 80%) from LDHs particles by a 5 wt% NaOH solution. The regeneration rate of used LDHs was approximately 60% after six cycles of adsorption-desorption-regeneration.

  2. Structural and Crystal Chemical Properties of Alkali Rare-earth Double Phosphates

    DOE PAGES

    Farmer, James Matthew; Boatner, Lynn A.; Chakoumakos, Bryan C.; ...

    2016-01-01

    When appropriately activated, alkali rare-earth double phosphates of the form: M3RE(PO4)2 (where M denotes an alkali metal and RE represents either a rare-earth element or Y or Sc) are of interest for use as inorganic scintillators for radiation detection at relatively long optical emission wavelengths. These compounds exhibit layered crystal structures whose symmetry properties depend on the relative sizes of the rare-earth and alkali-metal cations. Single-crystal X-ray and powder neutron diffraction methods were used here to refine the structures of the series of rare-earth double phosphate compounds: K3RE(PO4)2 with RE = Lu, Er, Ho, Dy, Gd, Nd, Ce, plus Ymore » and Sc - as well as the compounds: A3Lu(PO4)2, with A = Rb, and Cs. The double phosphate K3Lu(PO4)2 was reported and structurally refined previously. This material had a hexagonal unit cell at room temperature with the Lu ion six-fold coordinated with oxygen atoms of the surrounding phosphate groups. Additionally two lower-temperature phases were observed for K3Lu(PO4)2. The first phase transition to a monoclinic P21/m phase occurred at ~230 K, and the Lu ion retained its six-fold coordination. The second K3Lu(PO4)2 phase transition occurred at ~130 K. The P21/m space group symmetry was retained, however, one of the phosphate groups rotated to increase the oxygen coordination number of Lu from six to seven. This structure then became isostructural with the room-temperature form of the compound K3Yb(PO4)2 reported here that also exhibits an additional high-temperature phase which occurs at T = 120 °C with a transformation to hexagonal P-3 space group symmetry and a Yb-ion coordination number reduction from seven to six. This latter result was confirmed using EXAFS. The single-crystal growth methods structural systematics, and thermal expansion properties of the present series of alkali rare-earth double phosphates, as determined by X-ray and neutron diffraction methods, are treated here.« less

  3. Structural and Crystal Chemical Properties of Alkali Rare-earth Double Phosphates

    SciTech Connect

    Farmer, James Matthew; Boatner, Lynn A.; Chakoumakos, Bryan C.; Rawn, Claudia J.; Richardson, Jim

    2016-01-01

    When appropriately activated, alkali rare-earth double phosphates of the form: M3RE(PO4)2 (where M denotes an alkali metal and RE represents either a rare-earth element or Y or Sc) are of interest for use as inorganic scintillators for radiation detection at relatively long optical emission wavelengths. These compounds exhibit layered crystal structures whose symmetry properties depend on the relative sizes of the rare-earth and alkali-metal cations. Single-crystal X-ray and powder neutron diffraction methods were used here to refine the structures of the series of rare-earth double phosphate compounds: K3RE(PO4)2 with RE = Lu, Er, Ho, Dy, Gd, Nd, Ce, plus Y and Sc - as well as the compounds: A3Lu(PO4)2, with A = Rb, and Cs. The double phosphate K3Lu(PO4)2 was reported and structurally refined previously. This material had a hexagonal unit cell at room temperature with the Lu ion six-fold coordinated with oxygen atoms of the surrounding phosphate groups. Additionally two lower-temperature phases were observed for K3Lu(PO4)2. The first phase transition to a monoclinic P21/m phase occurred at ~230 K, and the Lu ion retained its six-fold coordination. The second K3Lu(PO4)2 phase transition occurred at ~130 K. The P21/m space group symmetry was retained, however, one of the phosphate groups rotated to increase the oxygen coordination number of Lu from six to seven. This structure then became isostructural with the room-temperature form of the compound K3Yb(PO4)2 reported here that also exhibits an additional high-temperature phase which occurs at T = 120 °C with a transformation to hexagonal P-3 space group symmetry and a Yb-ion coordination number reduction from seven to six. This latter result was confirmed using EXAFS. The single

  4. Sequestration of Sr-90 Subsurface Contamination in the Hanford 100-N Area by Surface Infiltration of a Ca-Citrate-Phosphate Solution

    SciTech Connect

    Szecsody, James E.; Rockhold, Mark L.; Oostrom, Martinus; Moore, R. C.; Burns, Carolyn A.; Williams, Mark D.; Zhong, Lirong; Fruchter, Jonathan S.; McKinley, James P.; Vermeul, Vincent R.; Covert, Matthew A.; Wietsma, Thomas W.; Breshears, Andrew T.; Garcia, Ben J.

    2009-03-01

    The objective of this project is to develop a method to emplace apatite precipitate in the 100N vadose zone, which results in sorption and ultimately incorporation of Sr-90 into the apatite structure. The Ca-citrate-PO4 solution can be infiltrated into unsaturated sediments to result in apatite precipitate to provide effective treatment of Sr-90 contamination. Microbial redistribution during solution infiltration and a high rate of citrate biodegradation for river water microbes (water used for solution infiltration) results in a relatively even spatial distribution of the citrate biodegradation rate and ultimately apatite precipitate in the sediment. Manipulation of the Ca-citrate-PO4 solution infiltration strategy can be used to result in apatite precipitate in the lower half of the vadose zone (where most of the Sr-90 is located) and within low-K layers (which are hypothesized to have higher Sr-90 concentrations). The most effective infiltration strategy to precipitate apatite at depth (and with sufficient lateral spread) was to infiltrate a high concentration solution (6 mM Ca, 15 mM citrate, 60 mM PO4) at a rapid rate (near ponded conditions), followed by rapid, then slow water infiltration. Repeated infiltration events, with sufficient time between events to allow water drainage in the sediment profile can be used to buildup the mass of apatite precipitate at greater depth. Low-K heterogeneities were effectively treated, as the higher residual water content maintained in these zones resulted in higher apatite precipitate concentration. High-K zones did not receive sufficient treatment by infiltration, although an alternative strategy of air/surfactant (foam) was demonstrated effective for targeting high-K zones. The flow rate manipulation used in this study to treat specific depths and heterogeneities are not as easy to implement at field scale due to the lack of characterization of heterogeneities and difficulty tracking the wetting front over a large

  5. Metformin administration versus laparoscopic ovarian diathermy in clomiphene citrate-resistant women with polycystic ovary syndrome: a prospective parallel randomized double-blind placebo-controlled trial.

    PubMed

    Palomba, Stefano; Orio, Francesco; Nardo, Luciano Giovanni; Falbo, Angela; Russo, Tiziana; Corea, Domenico; Doldo, Patrizia; Lombardi, Gaetano; Tolino, Achille; Colao, Annamaria; Zullo, Fulvio

    2004-10-01

    At present, it is unclear what the role is of laparoscopic ovarian diathermy (LOD) and of metformin administration as second-line treatments for ovulation induction in women with polycystic ovary syndrome (PCOS) after failure of clomiphene citrate (CC) treatment. The aim of the present study was to compare in a randomized double-blind placebo-controlled fashion the effectiveness of LOD with metformin administration in the treatment of CC-resistant women with PCOS. A total of 120 overweight primary infertile anovulatory CC-resistant women with PCOS were enrolled and randomized into two groups of treatment. Group A underwent diagnostic laparoscopy, whereas group B underwent LOD. At hospital discharge, the patients were treated for 6 months with metformin cloridrate (group A; 850 mg twice daily) or with multivitamins (group B). The ovulation, pregnancy, abortion, and live-birth rates were evaluated. At the end of the study, the total ovulation rate was not statistically different between both treatment groups (54.8 vs. 53.2% [correction] in groups A and B, respectively), whereas the pregnancy (21.8 [correction] vs. 13.4%), the abortion (9.3 [correction] vs. 29.0%), and the live-birth (86.0 [correction] vs. 64.5%) rates were significantly (P < 0.05) different between the two groups. Our data show that metformin administration is more effective than LOD in overall reproductive outcomes in overweight infertile CC-resistant women with PCOS.

  6. The electronic structure and optical properties of ABP 2O 7 ( A = Na, Li) double phosphates

    NASA Astrophysics Data System (ADS)

    Hizhnyi, Yu. A.; Oliynyk, A.; Gomenyuk, O.; Nedilko, S. G.; Nagornyi, P.; Bojko, R.; Bojko, V.

    2008-01-01

    Partial densities of states and reflection spectra of NaAlP 2O 7, KAlP 2O 7 and LiInP 2O 7 double phosphate crystals are calculated by the full-potential linear-augmented-plane-wave (FLAPW) method. Experimental reflection spectra of KAlP 2O 7, CsAlP 2O 7 and NaInP 2O 7 are measured in the 4-20 eV energy range. The values of band gaps, Eg, are found from a comparison of experiment and calculations to be 6.0 eV for NaAlP 2O 7 and KAlP 2O 7, and 4.6 eV for LiInP 2O 7.

  7. Competitive adsorption characteristics of fluoride and phosphate on calcined Mg-Al-CO3 layered double hydroxides.

    PubMed

    Cai, Peng; Zheng, Hong; Wang, Chong; Ma, Hongwen; Hu, Jianchao; Pu, Yubing; Liang, Peng

    2012-04-30

    With synthetic wastewater, competitive adsorption characteristics of fluoride and phosphate on calcined Mg-Al-CO(3) layered double hydroxides (CLDH) were investigated. A series of batch experiments were performed to study the influence of various experimental parameters, such as pH, contact time, and order of addition of the anions on the competitive adsorption of fluoride and phosphate on CLDH. It was found that the optimal pH is around 6 and it took 24 h to attain equilibrium when fluoride and phosphate were simultaneous added. The order of addition of anions influenced the adsorption of fluoride and phosphate on CLDH. The kinetic data were analyzed using the pseudo first-order and pseudo second-order models and they were found to fit very well the pseudo second-order kinetic model. Data of equilibrium experiments were fitted well to Langmuir isotherm and the competitive monolayer adsorption capacities of fluoride and phosphate were found to be obviously lower than those of single anion at 25 °C. The results of X-ray diffraction, Scanning Electron Microscopy with energy-dispersive X-ray analyses, and ATR-FTIR demonstrate that the adsorption mechanism involves the rehydration of mixed metal oxides and concomitant intercalation of fluoride and phosphate ions into the interlayer to reconstruct the initial LDHs structure.

  8. The alternative use of layered double hydroxides as extraction medium coupled with microcomplexation for determination of phosphate in water samples

    NASA Astrophysics Data System (ADS)

    Gissawong, Netsirin; Sansuk, Sira; Srijaranai, Supalax

    2017-02-01

    A simple, rapid, in situ, and green extraction combined with a microcomplexation has been developed for the spectrophotometric determination of phosphate in water samples. Through their formation, layered double hydroxides (LDHs) were employed as the extraction medium, instantly commenced by a rapid addition of a mixed solution of Mg2 + and Al3 + ions into alkaline phosphate solution. After the extraction, LDH precipitate containing phosphate was dissolved by sulfuric acid and the released phosphate was subsequently detected via its complexation with molybdate in the presence of antimonyl and ascorbic acid. Under optimum conditions, the linearity in the range of 5-200 μg L- 1, with the correlation coefficient (r2) of 0.9969, and the enrichment factor (EF) of 14 were obtained. The limit of detection (LOD) of 5 μg L- 1 and good precision, with the relative standard deviations (RSDs) less than 8.16%, were achieved. The proposed method was successfully applied to determine phosphate in water samples and the relative recoveries of 72.97-115.32% were obtained.

  9. The alternative use of layered double hydroxides as extraction medium coupled with microcomplexation for determination of phosphate in water samples.

    PubMed

    Gissawong, Netsirin; Sansuk, Sira; Srijaranai, Supalax

    2017-02-15

    A simple, rapid, in situ, and green extraction combined with a microcomplexation has been developed for the spectrophotometric determination of phosphate in water samples. Through their formation, layered double hydroxides (LDHs) were employed as the extraction medium, instantly commenced by a rapid addition of a mixed solution of Mg(2+) and Al(3+) ions into alkaline phosphate solution. After the extraction, LDH precipitate containing phosphate was dissolved by sulfuric acid and the released phosphate was subsequently detected via its complexation with molybdate in the presence of antimonyl and ascorbic acid. Under optimum conditions, the linearity in the range of 5-200μgL(-1), with the correlation coefficient (r(2)) of 0.9969, and the enrichment factor (EF) of 14 were obtained. The limit of detection (LOD) of 5μgL(-1) and good precision, with the relative standard deviations (RSDs) less than 8.16%, were achieved. The proposed method was successfully applied to determine phosphate in water samples and the relative recoveries of 72.97-115.32% were obtained.

  10. The Safety and Tolerability of 5-Aminolevulinic Acid Phosphate with Sodium Ferrous Citrate in Patients with Type 2 Diabetes Mellitus in Bahrain

    PubMed Central

    Al-Saber, Feryal; Aldosari, Waleed; Alselaiti, Mariam; Khalfan, Hesham; Kaladari, Ahmed; Khan, Ghulam; Harb, George; Rehani, Riyadh; Kudo, Sizuka; Koda, Aya; Tanaka, Tohru

    2016-01-01

    Type 2 diabetes mellitus is prevalent especially in Gulf countries and poses serious long-term risks to patients. A multifaceted treatment approach can include nutritional supplements with antioxidant properties such as 5-aminolevulinic acid (5-ALA) with sodium ferrous citrate (SFC). This prospective, randomized, single-blind, placebo-controlled, dose escalating pilot clinical trial assessed the safety of 5-ALA with SFC at doses up to 200 mg 5-ALA/229.42 mg SFC per day in patients living in Bahrain with type 2 diabetes mellitus that was uncontrolled despite the use of one or more antidiabetic drugs. Fifty-three patients (n = 53) from 3 sites at one center were enrolled by Dr. Feryal (Site #01), Dr. Hesham (Site #02), and Dr. Waleed (Site #03) (n = 35, 5-ALA-SFC; n = 18, placebo). There was no significant difference in incidence of adverse events reported, and the most frequent events reported were gastrointestinal in nature, consistent with the known safety profile of 5-ALA in patients with diabetes. No significant changes in laboratory values and no difference in hypoglycemia between patients receiving 5-ALA and placebo were noted. Overall, the current results support that use of 5-ALA-SFC up to 200 mg per day taken as 2 divided doses is safe in patients taking concomitant oral antidiabetic medications and may offer benefits in the diabetic population. This trial is registered with ClinicalTrials.gov NCT02481141. PMID:27738640

  11. Nickel sorption to goethite and montmorillonite in presence of citrate.

    PubMed

    Marcussen, Helle; Holm, Peter E; Strobel, Bjarne W; Hansen, Hans Chr B

    2009-02-15

    Mobility and bioavailability of nickel (Ni) in soil strongly depends on the interaction between Ni(II), ligands, and sorbents like organic matter and minerals. Sorption of Ni(II) and Ni(II)-citrate complexes to goethite and montmorillonite was examined in batch experiments with and without citrate as ligand in the pH range pH 4-7.5. Without citrate, montmorillonite shows higher Ni sorption than goethite. Citrate strongly decreases Ni sorption to montmorillonite; in presence of 100 microM citrate goethite becomes a stronger Ni sorbent than montmorillonite. Ni and citrate sorption was modeled successfully using the diffuse double layer model with the following reactions: Goethite: 3 [triple bond]FeOH + Citrate(3-) + 3H+ <=> [triple bond] Fe3Citrate + 3H2O, [triple bond]FeOH + Ni2+ <=> [triple bond] FeONi + H+ and 2 [triple bond] FeOH + Citrate(3)- + Ni2+ <=> [triple bond] FeONiCitrate(2-) + H+. Montmorillonite: 2X- + Ni2+ <=> X2Ni and [triple bond] AIOH + Ni2+ <=> AIONi+ + H+. Sorption of Ni to a mixture of goethite and montmorillonite could be calculated by use of reactions and constants for the monomineral systems. Without citrate, the sorbed amount of Ni per mass unit in the mixture can be found as a simple average of sorption to the two single sorbents, while in presence of citrate Ni sorption to montmorillonite is strongly influenced by citrate sorption to goethite.

  12. Cerium-activated rare-earth orthophosphate and double-phosphate scintillators for x-and gamma-ray detection

    SciTech Connect

    Boatner, Lynn A; Keefer, Lara A; Farmer, James Matthew; Wisniewski, D.; Wojtowicz, A. J.

    2004-01-01

    When activated with an appropriate rare-earth ion (e.g., Ce or Nd), rare-earth orthophosphates of the form REPO4 (where RE = a rare-earth cation) and alkali rare-earth double phosphates of the form A{sub 3}RE(PO{sub 4}){sub 2} (where A = K, Rb, or Cs) are characterized by light yields and decay times that make these materials of interest for radiation-detection applications. Crystals of the compound Rb{sub 3}Lu(PO{sub 4}){sub 2} when activated with {approx}0.1 mol % Ce exhibit a light yield that is {approx}250% that of BGO with a decay time on the order of {approx}40 nsec. The cerium-activated rare-earth orthophosphate LuPO{sub 4}:Ce is also characterized by a high light yield and a relatively fast decay time of {approx}25 nsec. Additionally, the rare-earth orthophosphates are extremely chemically, physically, and thermally durable hosts that recover easily from radiation damage effects. The properties of the rare-earth orthophosphates and double phosphates that pertain to their use as X- and gamma-ray detectors are reviewed. This review includes information related to the use of Nd-doped LuPO{sub 4} as a scintillator with a sufficiently energetic, short-wavelength output ({lambda} = 90 nm) so that it can be used in conjunction with appropriately activated proportional counters. Information is presented on the details of the synthesis, structure, and luminescence properties of lanthanide double phosphates that, when activated with cerium, are efficient scintillators with output wavelengths that are sufficiently long to be well matched to the response of silicon photodiode detectors.

  13. Gastrointestinal citrate absorption in nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Fegan, J.; Khan, R.; Poindexter, J.; Pak, C. Y.

    1992-01-01

    Gastrointestinal absorption of citrate was measured in stone patients with idiopathic hypocitraturia to determine if citrate malabsorption could account for low urinary citrate. Citrate absorption was measured directly from recovery of orally administered potassium citrate (40 mEq.) in the intestinal lavage fluid, using an intestinal washout technique. In 7 stone patients citrate absorption, serum citrate levels, peak citrate concentration in serum and area under the curve were not significantly different from those of 7 normal subjects. Citrate absorption was rapid and efficient in both groups, with 96 to 98% absorbed within 3 hours. The absorption of citrate was less efficient from a tablet preparation of potassium citrate than from a liquid preparation, probably due to a delayed release of citrate from wax matrix. However, citrate absorption from solid potassium citrate was still high at 91%, compared to 98% for a liquid preparation. Thus, hypocitraturia is unlikely to be due to an impaired gastrointestinal absorption of citrate in stone patients without overt bowel disease.

  14. Effects of supplementation on food intake, body weight and hepatic metabolites in the citrin/mitochondrial glycerol-3-phosphate dehydrogenase double-knockout mouse model of human citrin deficiency.

    PubMed

    Saheki, Takeyori; Inoue, Kanako; Ono, Hiromi; Katsura, Natsumi; Yokogawa, Mana; Yoshidumi, Yukari; Furuie, Sumie; Kuroda, Eishi; Ushikai, Miharu; Asakawa, Akihiro; Inui, Akio; Eto, Kazuhiro; Kadowaki, Takashi; Sinasac, David S; Yamamura, Ken-Ichi; Kobayashi, Keiko

    2012-11-01

    The C57BL/6:Slc23a13(-/-);Gpd2(-/-) double-knockout (a.k.a., citrin/mitochondrial glycerol 3-phosphate dehydrogenase double knockout or Ctrn/mGPD-KO) mouse displays phenotypic attributes of both neonatal intrahepatic cholestasis (NICCD) and adult-onset type II citrullinemia (CTLN2), making it a suitable model of human citrin deficiency. In the present study, we show that when mature Ctrn/mGPD-KO mice are switched from a standard chow diet (CE-2) to a purified maintenance diet (AIN-93M), this resulted in a significant loss of body weight as a result of reduced food intake compared to littermate mGPD-KO mice. However, supplementation of the purified maintenance diet with additional protein (from 14% to 22%; and concomitant reduction or corn starch), or with specific supplementation with alanine, sodium glutamate, sodium pyruvate or medium-chain triglycerides (MCT), led to increased food intake and body weight gain near or back to that on chow diet. No such effect was observed when supplementing the diet with other sources of fat that contain long-chain fatty acids. Furthermore, when these supplements were added to a sucrose solution administered enterally to the mice, which has been shown previously to lead to elevated blood ammonia as well as altered hepatic metabolite levels in Ctrn/mGPP-KO mice, this led to metabolic correction. The elevated hepatic glycerol 3-phosphate and citrulline levels after sucrose administration were suppressed by the administration of sodium pyruvate, alanine, sodium glutamate and MCT, although the effect of MCT was relatively small. Low hepatic citrate and increased lysine levels were only found to be corrected by sodium pyruvate, while alanine and sodium glutamate both corrected hepatic glutamate and aspartate levels. Overall, these results suggest that dietary factors including increased protein content, supplementation of specific amino acids like alanine and sodium glutamate, as well as sodium pyruvate and MCT all show beneficial

  15. [Influence of reaction time of urea hydrolysis-based co-precipitation on the structure of ZnAl layered double hydroxides and the phosphate adsorption].

    PubMed

    Lu, Ying; Cheng, Xiang; Xing, Bo; Sun, Zhong-en; Sun, De-zhi

    2012-08-01

    A series of ZnAl layered double hydroxides (LDHs) were prepared by urea hydrolysis-based homogeneous co-precipitation for studying their structure and phosphate adsorption capacities. The results show that all the samples exhibited a typical layered structure as the reaction time extended from 12 h to 96 h, whereas Zn/Al molar ratio in the ZnAls decreased from 2.06 to 0.70 and the specific surface area markedly increased to be 7.6-fold higher than that of ZnAl-12. Phosphate adsorption capacity of the ZnAl was in general increased gradually with the reaction time extension, which can be attributed to the surface area rising as well as the increased positive charge of LDHs layer caused by a higher proportion of Al. This reveals that physicochemical adsorption on LDHs surface would have played an important role during the phosphate adsorption. With a reaction time of 24 h, a high amount of exchangeable interlayer anions was observed, giving rise to a highest phosphate uptake of 34.1 mg x g(-1) by the ZnAl-24. It indicates the ion exchange was another major pathway for the phosphate removal. For all the ZnAls with different reaction times, the phosphate adsorption isotherms fit well with Langmuir-type equations; the adsorption kinetics followed pseudo-second-order models.

  16. [Contribution to the problem of preventing recurrences of oxalate and phosphate urinary caluli: active modification of citrate excretion and Ca++-binding capacity in the urine of Wistar rats].

    PubMed

    Leskovar, P; Hropot, M; Wellnhofer, E; Scherm, D; Schade, K L

    1982-03-01

    Citric acid may well be, quantitatively and in terms of complex chemistry, the most important of the organic acids capable of binding Ca++ in urine. Since the quantitative determination of citrates in urine became a routine method in many research-orientated urological laboratories thanks to the introduction of standardized enzymatic tests, reports of a reduced excretion of citrates in patients with (recurrent) (oxalate) calculi have become frequent. During our long-term study of patients with recurrent formation of calculi we also observed a clear deficit of citrates in their morning, midday and evening urine. The conspicuous incidence of calculi when there is a concurrence of hypocitraturia and alkaline urine (RTA, in animal experiments: acetazolamide) clearly suggests the lithoprotective significance of citric acid. By quantitatively testing a large number of organic compounds which are interesting both structurally and in terms of complex chemistry, it has been possible to find some substances which restrict crystallization, raise the level of citrates and bind Ca++. A few have also found to restrict the excretion of oxalate in Wistar rats.

  17. Final report on the safety assessment of acetyl triethyl citrate, acetyl tributyl citrate, acetyl trihexyl citrate, and acetyl trioctyl citrate.

    PubMed

    Johnson, Wilbur

    2002-01-01

    Acetyl Triethyl Citrate, Acetyl Tributyl Citrate, Acetyl Trihexyl Citrate, and Acetyl Trioctyl Citrate all function as plasticizers in cosmetics. Additionally, the Trihexyl and Trioctyl forms are described as skin-conditioning agents-emollients, although there are currently no reported uses of Acetyl Trihexyl Citrate or Acetyl Trioctyl Citrate. Acetyl Triethyl Citrate and Acetyl Tributyl Citrate are used in nail products at concentrations up to 7%. Recognizing that there are no reported uses of Acetyl Trihexyl or Trioctyl Citrate, if they were to be used in the future, their concentration of use is expected to be no higher than that reported for Acetyl Triethyl and Tributyl Citrate. These ingredients were sufficiently similar in structure that safety test data on one were considered applicable to all. Approximately 99% of orally administered Acetyl Tributyl Citrate is excreted-intermediate metabolites include acetyl citrate, monobutyl citrate, acetyl monobutyl citrate, dibutyl citrate, and acetyl dibutyl citrate. In acute, short-term, subchronic, and chronic feeding studies, these ingredients were relatively nontoxic. Differences from controls were either not statistically significant or not related to any organ toxicity. Ocular exposures produced moderate reactions that cleared by 48 hours after instillation. Dermal application was not toxic in rabbits. In a guinea pig maximization test, Acetyl Triethyl Citrate was a sensitizer whereas Acetyl Tributyl Citrate was not. Limited clinical testing of Acetyl Triethyl Citrate and Acetyl Tributyl Citrate was negative for both skin irritation and sensitization. These clinical data were considered more relevant than the guinea pig maximization data, suggesting to the Cosmetic Ingredient Review Expert Panel that none of these ingredients would be a sensitizer. Physiologic effects noted with intravenous delivery of Acetyl Triethyl Citrate or Acetyl Tributyl Citrate include dose-related decreases in blood pressure and

  18. Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31P and double-quantum filtered 23Na NMR spectroscopy.

    PubMed

    Gobet, Mallory; Rondeau-Mouro, Corinne; Buchin, Solange; Le Quéré, Jean-Luc; Guichard, Elisabeth; Foucat, Loïc; Moreau, Céline

    2010-04-01

    The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in the cheeses was validated. The presence of a fraction of 'bound' sodium ions was evidenced by (23)Na double-quantum filtered NMR experiments. We demonstrated that NMR is a suitable tool to investigate both phosphates and Na(+) ions distributions in cheeses. The impact of the sodium content on the various phosphorus forms distribution was discussed and results demonstrated that NMR would be an important tool for the cheese industry for the processes controls.

  19. Strongly bound citrate stabilizes the apatite nanocrystals in bone

    SciTech Connect

    Hu, Y.-Y.; Rawal, A.; Schmidt-Rohr, K.

    2010-10-12

    Nanocrystals of apatitic calcium phosphate impart the organic-inorganic nanocomposite in bone with favorable mechanical properties. So far, the factors preventing crystal growth beyond the favorable thickness of ca. 3 nm have not been identified. Here we show that the apatite surfaces are studded with strongly bound citrate molecules, whose signals have been identified unambiguously by multinuclear magnetic resonance (NMR) analysis. NMR reveals that bound citrate accounts for 5.5 wt% of the organic matter in bone and covers apatite at a density of about 1 molecule per (2 nm){sup 2}, with its three carboxylate groups at distances of 0.3 to 0.45 nm from the apatite surface. Bound citrate is highly conserved, being found in fish, avian, and mammalian bone, which indicates its critical role in interfering with crystal thickening and stabilizing the apatite nanocrystals in bone

  20. The role of molecular structure of sugar-phosphate backbone and nucleic acid bases in the formation of single-stranded and double-stranded DNA structures.

    PubMed

    Poltev, Valeri; Anisimov, Victor M; Danilov, Victor I; Garcia, Dolores; Sanchez, Carolina; Deriabina, Alexandra; Gonzalez, Eduardo; Rivas, Francisco; Polteva, Nina

    2014-06-01

    Our previous DFT computations of deoxydinucleoside monophosphate complexes with Na(+)-ions (dDMPs) have demonstrated that the main characteristics of Watson-Crick (WC) right-handed duplex families are predefined in the local energy minima of dDMPs. In this work, we study the mechanisms of contribution of chemically monotonous sugar-phosphate backbone and the bases into the double helix irregularity. Geometry optimization of sugar-phosphate backbone produces energy minima matching the WC DNA conformations. Studying the conformational variability of dDMPs in response to sequence permutation, we found that simple replacement of bases in the previously fully optimized dDMPs, e.g. by constructing Pyr-Pur from Pur-Pyr, and Pur-Pyr from Pyr-Pur sequences, while retaining the backbone geometry, automatically produces the mutual base position characteristic of the target sequence. Based on that, we infer that the directionality and the preferable regions of the sugar-phosphate torsions, combined with the difference of purines from pyrimidines in ring shape, determines the sequence dependence of the structure of WC DNA. No such sequence dependence exists in dDMPs corresponding to other DNA conformations (e.g., Z-family and Hoogsteen duplexes). Unlike other duplexes, WC helix is unique by its ability to match the local energy minima of the free single strand to the preferable conformations of the duplex.

  1. Simplified citrate anticoagulation for high-flux hemodialysis.

    PubMed

    Apsner, R; Buchmayer, H; Lang, T; Unver, B; Speiser, W; Sunder-Plassmann, G; Hörl, W H

    2001-11-01

    In a randomized crossover trial, we compared a simple citrate anticoagulation protocol for high-flux hemodialysis with standard anticoagulation by low-molecular-weight heparin (dalteparin). Primary end points were urea reduction rate (URR), Kt/V, and control of electrolyte and acid-base homeostasis. Secondary end points were bleeding time at vascular puncture sites and markers of activation of platelets, coagulation, and fibrinolysis. Solute removal during citrate dialysis was excellent (URR, 0.71 +/- 0.06; Kt/V, 1.55 +/- 0.3) and similar to results of conventional bicarbonate hemodialysis anticoagulation with dalteparin (URR, 0.72 +/- 0.04; Kt/V, 1.56 +/- 0.2). Electrolyte control was effective with both anticoagulation regimens, and total and ionized calcium, sodium, potassium, and phosphate concentrations at the end of dialysis did not differ. Alkalemia was less frequent after citrate than conventional dialysis (pH 7.5 in 25% versus 62% of patients; mean pH at end of dialysis, 7.46 +/- 0.06 versus 7.51 +/- 0.07; P < 0.01). Bleeding time at puncture sites was shorter by 30% after citrate compared with dalteparin anticoagulation (5.43 +/- 2.80 versus 7.86 +/- 2.93 minutes; P < 0.001). Activation of platelets, coagulation, and fibrinolysis was modest for both treatments and occurred mainly within the dialyzer during dalteparin treatment and in the vascular-access region during citrate anticoagulation. Citrate-related adverse events were not observed. We conclude that citrate anticoagulation for high-flux hemodialysis is feasible and safe using a simple infusion protocol.

  2. Colloid mobilization in the field using citrate to remediate chromium.

    PubMed

    Johnson, C R; Hellerich, L A; Nikolaidis, N P; Gschwend, P M

    2001-01-01

    We investigated the feasibility of cleaning aquifer sediments, long contaminated with chromium (Cr) from a metal plating facility, by detaching colloid-sized sorbents from the immobile aquifer solids and then pumping those colloids to the surface for treatment. In laboratory experiments using aquifer solids from the site, several solutions (water at various pHs, phosphate, oxalate, ascorbate, citrate) were examined for their ability to disperse colloids and Cr. Based on these tests, a 5 mM citrate solution at pH 7 was selected. Subsequently, such a citrate solution was used in the field in two single-well injection-withdrawal experiments. Large quantities of colloids were released immediately after injection. The colloidal particles mobilized by citrate in the field had more than 20 times higher Cr concentrations than did the average aquifer sediments, implying success in mobilizing Cr-associated phases. Further, laboratory and field tests showed that anion exchange of citrate for chromate caused some additional release of Cr from these aquifer solids.

  3. [Observation for CH4 and N2O emissions under different rates of nitrogen and phosphate fertilization in double rice fields].

    PubMed

    Shi, Sheng-Wei; Li, Yu-E; Wan, Yun-Fan; Qin, Xiao-Bo; Gao, Qing-Zhu

    2011-07-01

    Two non-CO2 greenhouse gas emissions (methane and nitrous oxide) and related environmental factors were measured within rice growing season under five treatments including non-fertilization (CK), balanced fertilization (BF), decreased nitrogen and phosphate 1 (DNP1), decreased nitrogen and phosphate 2 (DNP2) and increased nitrogen and phosphate 1 (INP) in double rice fields of red clay soil in 2009, using the method of static chamber-gas chromatograph techniques. The results showed that the average CH4 emission fluxes for treatments of BF, DNP1, DNP2 and INP were 4.57, 5.42, 4.70 and 4.65 mg x (m2 x h)(-1) during early rice growing period, which increased by 39%, 49%, 41% and 40% compared with non-fertilizer treatment, respectively. The average CH4 emission fluxes in late rice growing season was higher than preseason's. Compared to CK, CH4 emission increased by 11%, 1%, 26% and - 4% in treatments of BF, DNP1, DNP2 and INP within late rice growing season. Applying nitrogen and phosphate enhanced CH4 emission in turning green period for early and late rice. No significant difference was observed between the CH4 emissions of five treatments during early and late rice growing season (p > 0.05). N2O emission was very little during mid-seasonal drainage period. In contrast, N2O emission peaks were observed in period of alternation of wetting and drying after mid-seasonal drainage in this experiment. N2O emission was, on average, equivalent to 0.18% of the nitrogen applied in double rice growing season. Statistically, air temperature, soil Eh and soil moisture (water-filled pore space, WFPS) at 0-10cm depth significantly affected the fluctuations of the seasonal CH4 flux, but no significant correlationship has been found between N2O flux and related environmental factors. CH4 was the dominated greenhouse gas in double rice fields which contributed approximately 90% for the integrated global warming potential of CH4 and N2O released during the rice growing season

  4. Probabilistic model-based methodology for the conformational study of cyclic systems: application to copper complexes double-bridged by phosphate and related ligands.

    PubMed

    Kessler, M; Pérez, J; Bueso, M C; García, L; Pérez, E; Serrano, J L; Carrascosa, R

    2007-12-01

    A methodology for the conformational study of cyclic systems through the statistical analysis of torsion angles is presented. It relies on a combination of different methods based on a probabilistic model which takes into account the topological symmetry of the structures. This methodology is applied to copper complexes double-bridged by phosphate and related ligands. Structures from the Cambridge Structural Database (CSD) are analyzed and the chair, boat-chair and boat conformations are identified as the most frequent conformations. The output of the methodology also provides information about distortions from the ideal conformations, the most frequent being: chair <--> twist-chair, chair <--> twist-boat-chair and boat <--> twist-boat. Molecular mechanics calculations identify these distortions as energetically accessible pathways.

  5. Citrate and Sugar Cofermentation in Leuconostoc oenos, a (sup13)C Nuclear Magnetic Resonance Study

    PubMed Central

    Ramos, A.; Santos, H.

    1996-01-01

    (sup13)C nuclear magnetic resonance spectroscopy was used to investigate citrate-glucose cometabolism in nongrowing cell suspensions of the wine lactic acid bacterium Leuconostoc oenos. The use of isotopically enriched substrates allowed us to identify and quantify in the end products the carbon atoms derived from each of the substrates supplied; furthermore, it was possible to differentiate between products derived from the metabolism of endogenous carbon reserves and those derived from external substrates. Citrate-sugar cometabolism was also monitored in dilute cell suspensions for comparison with the nuclear magnetic resonance results. A clear metabolic shift of the end products from glucose metabolism was observed when citrate was provided along with glucose: ethanol was replaced by acetate, and 2,3-butanediol was produced. Reciprocally, the production of lactate and 2,3-butanediol from citrate was increased in the presence of glucose. When citrate was cometabolized with glucose, a 10-fold reduction in the intracellular concentration of glucose-6-phosphate was observed, a result in line with the observed citrate-induced stimulation of glucose consumption. The presence of citrate provided additional pathways for NADP(sup+) regeneration and allowed the diversion of sugar carbon to reactions in which ATP was synthesized. The increased growth rates and maximal biomass yields of L. oenos growing on citrate-glucose mixtures resulted from increased ATP synthesis both by substrate-level phosphorylation and by a chemiosmotic mechanism. PMID:16535363

  6. Characterization of citrate utilization in Corynebacterium glutamicum by transcriptome and proteome analysis.

    PubMed

    Polen, Tino; Schluesener, Daniela; Poetsch, Ansgar; Bott, Michael; Wendisch, Volker F

    2007-08-01

    Corynebacterium glutamicum grows aerobically on a variety of carbohydrates and organic acids as single or combined sources of carbon and energy. To characterize the citrate utilization in C. glutamicum on a genomewide scale, a comparative analysis was carried out by combining transcriptome and proteome analysis. In cells grown on citrate, transcriptome analysis revealed highest expression changes for two different citrate-uptake systems encoded by citM and tctCBA, whereas genes encoding uptake systems for the glucose- (ptsG), sucrose- (ptsS) and fructose- (ptsF) specific PTS components and permeases for gluconate (gntP) and glutamate (gluC) displayed decreased mRNA levels in citrate-grown cells. This pattern was also observed when cells grown in Luria-Bertani (LB) medium plus citrate were compared with cells grown in LB medium, indicating some kind of catabolite repression. Genes encoding enzymes of the tricarboxylic acid cycle (aconitase, succinyl-CoA synthetase, succinate dehydrogenase and fumarase), malic enzyme, PEP carboxykinase, gluconeogenic glyceraldehyde-3-phosphate dehydrogenase and ATP synthase displayed increased expression in cells grown on citrate. Accordingly, proteome analysis revealed elevated protein levels of these enzymes and showed a good correlation with the mRNA levels. In conclusion, this study revealed the citrate stimulon in C. glutamicum and the regulated central metabolic genes when grown on citrate.

  7. Iron-based phosphate binders: do they offer advantages over currently available phosphate binders?

    PubMed Central

    Negri, Armando Luis; Ureña Torres, Pablo Antonio

    2015-01-01

    Increased cardiovascular morbidity and mortality has been associated with the hyperphosphatemia seen in patients with end-stage chronic kidney disease (CKD). Oral phosphate binders are prescribed in these patients to prevent intestinal absorption of dietary phosphate and reduce serum phosphate. In prospective observational cohorts they have shown to decrease all-cause and cardiovascular mortality risk. Different problems have been associated with currently available phosphate binders as positive calcium balance and impaired outcomes with calcium-based phosphate binders or increased costs with non-calcium-based phosphate binders. Iron-based phosphate binders represent a new class of phosphate binders. Several iron-based phosphate binders have undergone testing in clinical trials. Ferric citrate (JTT-751) and sucroferric oxyhydroxide (PA21) are the two iron-based binders that have passed to the clinical field after being found safe and effective in decreasing serum phosphate. Iron from ferric citrate is partially absorbed compared to sucroferric oxyhydroxide. Ferric citrate usage could result in an important reduction in erythropoiesis-stimulating agent (ESA) and IV iron usage, resulting in significant cost savings. Sucroferric oxyhydroxide was effective in lowering serum phosphorus in dialysis patients with similar efficacy to sevelamer carbonate, but with lower pill burden, and better adherence. Ferric citrate may be more suited for the treatment of chronic hyperphosphatemia in CKD patients requiring iron supplements but its use may have been hampered by potential aluminum overload, as citrate facilitates its absorption; sucroferric oxyhydroxide may be more suited for hyperphosphatemic CKD patients not requiring iron supplementation, with low pill burden. PMID:25815172

  8. PHOSPHATE MANAGEMENT: FY2010 RESULTS OF PHOSPHATE PRECIPITATION TESTS

    SciTech Connect

    Hay, M.; King, W.

    2011-04-04

    The Phosphate Management program seeks to develop treatment options for caustic phosphate solutions resulting from the caustic leaching of the bismuth phosphate sludge. The SRNL subtask investigated the precipitation of phosphate salts from caustic solutions through addition of fluoride and by crystallization. The scoping tests examined the: precipitation of phosphate by the addition of sodium fluoride to form the sodium fluorophosphate double salt, Na{sub 7}F(PO{sub 4}){sub 2} {center_dot} 19H{sub 2}O, crystallization of phosphate by reducing the temperature of saturated phosphate solutions, and combinations of precipitation and crystallization. A simplified leachate simulant was used in the study produced by dissolving sodium phosphate in 1 M to 3.5 M sodium hydroxide solutions. The results show that all three processes; precipitation with sodium fluoride, crystallization, and combined precipitation/crystallization can be effective for removing large amounts of phosphate from solution. The combined process of precipitation/crystallization showed >90% removal of phosphate at all hydroxide concentrations when cooling a non-saturated phosphate solution from 65 C to 25 C. Based on the measured solubility of sodium phosphate, pH adjustment/caustic addition will also remove large amounts of phosphate from solution (>80%). For all three processes, the phosphate concentration in the caustic solution must be managed to keep the phosphate from becoming too concentrated and thereby potentially forming a solid mass of sodium phosphate after an effective phosphate removal process.

  9. Enhanced citric acid biosynthesis in Pseudomonas fluorescens ATCC 13525 by overexpression of the Escherichia coli citrate synthase gene.

    PubMed

    Buch, Aditi D; Archana, G; Kumar, G Naresh

    2009-08-01

    Citric acid secretion by fluorescent pseudomonads has a distinct significance in microbial phosphate solubilization. The role of citrate synthase in citric acid biosynthesis and glucose catabolism in pseudomonads was investigated by overexpressing the Escherichia coli citrate synthase (gltA) gene in Pseudomonas fluorescens ATCC 13525. The resultant approximately 2-fold increase in citrate synthase activity in the gltA-overexpressing strain Pf(pAB7) enhanced the intracellular and extracellular citric acid yields during the stationary phase, by about 2- and 26-fold, respectively, as compared to the control, without affecting the growth rate, glucose depletion rate or biomass yield. Decreased glucose consumption was paralleled by increased gluconic acid production due to an increase in glucose dehydrogenase activity. While the extracellular acetic acid yield increased in Pf(pAB7), pyruvic acid secretion decreased, correlating with an increase in pyruvate carboxylase activity and suggesting an increased demand for the anabolic precursor oxaloacetate. Activities of two other key enzymes, glucose-6-phosphate dehydrogenase and isocitrate dehydrogenase, remained unaltered, and the contribution of phosphoenolpyruvate carboxylase and isocitrate lyase to glucose catabolism was negligible. Strain Pf(pAB7) demonstrated an enhanced phosphate-solubilizing ability compared to the control. Co-expression of the Synechococcus elongatus PCC 6301 phosphoenolpyruvate carboxylase and E. coli gltA genes in P. fluorescens ATCC 13525, so as to supplement oxaloacetate for citrate biosynthesis, neither significantly affected citrate biosynthesis nor caused any change in the other physiological and biochemical parameters measured, despite approximately 1.3- and 5-fold increases in citrate synthase and phosphoenolpyruvate carboxylase activities, respectively. Thus, our results demonstrate that citrate synthase is rate-limiting in enhancing citrate biosynthesis in P. fluorescens ATCC 13525

  10. Total synthesis of alkyl citrate natural products.

    PubMed

    Rizzacasa, Mark A; Sturgess, Dayna

    2014-03-07

    This review highlights the synthesis of members of the alkyl citrate family of natural products. The focus is on the stereoselective construction of the alkyl citrate moiety common to these compounds.

  11. 21 CFR 582.1625 - Potassium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use....

  12. 21 CFR 582.6625 - Potassium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is...

  13. 21 CFR 582.6625 - Potassium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is...

  14. 21 CFR 582.1625 - Potassium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use....

  15. 21 CFR 582.1625 - Potassium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use....

  16. 21 CFR 582.1625 - Potassium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use....

  17. 21 CFR 582.1625 - Potassium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium citrate. 582.1625 Section 582.1625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1625 Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use....

  18. 21 CFR 582.6625 - Potassium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is...

  19. 21 CFR 582.6625 - Potassium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is...

  20. 21 CFR 582.6625 - Potassium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Potassium citrate. 582.6625 Section 582.6625 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Potassium citrate. (a) Product. Potassium citrate. (b) Conditions of use. This substance is...

  1. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate...

  2. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder and... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate...

  3. 21 CFR 582.6751 - Sodium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized...

  4. 21 CFR 582.1751 - Sodium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is...

  5. 21 CFR 582.1751 - Sodium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is...

  6. 21 CFR 582.6751 - Sodium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized...

  7. 21 CFR 582.1751 - Sodium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is...

  8. 21 CFR 582.6751 - Sodium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized...

  9. 21 CFR 582.6751 - Sodium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized...

  10. 21 CFR 582.1751 - Sodium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is...

  11. 21 CFR 582.1751 - Sodium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Sodium citrate. 582.1751 Section 582.1751 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is...

  12. 21 CFR 582.6751 - Sodium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Sodium citrate. 582.6751 Section 582.6751 Food and..., FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Sequestrants 2 § 582.6751 Sodium citrate. (a) Product. Sodium citrate. (b) Conditions of use. This substance is generally recognized...

  13. 21 CFR 184.1298 - Ferric citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Substances Affirmed as GRAS § 184.1298 Ferric citrate. (a) Ferric citrate (iron (III) citrate, C6H5FeO7, CAS Reg. No. 2338-05-8) is prepared from reaction of citric acid with ferric hydroxide. It is a compound of indefinite ratio of citric acid and iron. (b) The ingredient must be of a purity suitable for...

  14. 21 CFR 184.1298 - Ferric citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1298 Ferric citrate. (a) Ferric citrate (iron (III) citrate, C6H5FeO7, CAS Reg. No. 2338-05-8) is prepared from reaction of citric acid with ferric hydroxide. It is a compound of indefinite ratio of citric acid and iron. (b) The ingredient must be of a purity suitable for...

  15. The mechanisms of citrate on regulating the distribution of carbon flux in the biosynthesis of uridine 5'-monophosphate by Saccharomyces cerevisiae.

    PubMed

    Chen, Yong; Li, Shuya; Xiong, Jian; Li, Zhenjiang; Bai, Jianxin; Zhang, Lei; Ye, Qi; Ouyang, Pingkai; Ying, Hanjie

    2010-03-01

    A whole cell biocatalytic process for uridine 5'-monophosphate (UMP) production from orotic acid by Saccharomyces cerevisiae was developed. The concentration of UMP was increased by 23% when 1 g l(-1) sodium citrate was fed into the broth. Effects of citrate addition on UMP production were investigated. Glucose-6-phosphate pool was elevated by onefold, while FBP and pyruvate were decreased by 42% and 40%, respectively. Organic acid pools such as acetate and succinate were averagely decreased by 30% and 49%. The results demonstrated that manipulation of citrate levels could be used as a novel tool to regulate the metabolic fluxes distribution among glycolysis, pentose phosphate pathway, and TCA cycle.

  16. Evolution of a Double Amino Acid Substitution in the 5-Enolpyruvylshikimate-3-Phosphate Synthase in Eleusine indica Conferring High-Level Glyphosate Resistance1

    PubMed Central

    Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R. Douglas; Powles, Stephen B.

    2015-01-01

    Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I + P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action. PMID:25717039

  17. Evolution of a double amino acid substitution in the 5-enolpyruvylshikimate-3-phosphate synthase in Eleusine indica conferring high-level glyphosate resistance.

    PubMed

    Yu, Qin; Jalaludin, Adam; Han, Heping; Chen, Ming; Sammons, R Douglas; Powles, Stephen B

    2015-04-01

    Glyphosate is the most important and widely used herbicide in world agriculture. Intensive glyphosate selection has resulted in the widespread evolution of glyphosate-resistant weed populations, threatening the sustainability of this valuable once-in-a-century agrochemical. Field-evolved glyphosate resistance due to known resistance mechanisms is generally low to modest. Here, working with a highly glyphosate-resistant Eleusine indica population, we identified a double amino acid substitution (T102I+P106S [TIPS]) in the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) gene in glyphosate-resistant individuals. This TIPS mutation recreates the biotechnology-engineered commercial first generation glyphosate-tolerant EPSPS in corn (Zea mays) and now in other crops. In E. indica, the naturally evolved TIPS mutants are highly (more than 180-fold) resistant to glyphosate compared with the wild type and more resistant (more than 32-fold) than the previously known P106S mutants. The E. indica TIPS EPSPS showed very high-level (2,647-fold) in vitro resistance to glyphosate relative to the wild type and is more resistant (600-fold) than the P106S variant. The evolution of the TIPS mutation in crop fields under glyphosate selection is likely a sequential event, with the P106S mutation being selected first and fixed, followed by the T102I mutation to create the highly resistant TIPS EPSPS. The sequential evolution of the TIPS mutation endowing high-level glyphosate resistance is an important mechanism by which plants adapt to intense herbicide selection and a dramatic example of evolution in action.

  18. Citrate anticoagulation and adverse events.

    PubMed

    De Vos, J; Hombrouckx, R

    2003-01-01

    Several patients with heparin intolerance were dialysed with tri-sodium citrate as anticoagulant without acute clinical problems (good tolerance). After some weeks however problems arose. In all patients an alkalosis developed: the pre dialysis bicarbonate level rose progressively from 27 mmol/l to 40 mmol/l. This could be tempered by lowering the dialysis fluid bicarbonate concentration from 37 mmol/l to 25 mmol/l. A second problem was a progressive rise in pre dialysis sodium level from a mean of 136 mmol/l to 150 mmol/l. Adapting the dialysis fluid sodium concentration from 140 mmol/l towards 132 mmol/l could solve this. The third problem was a progressive rise in serum aluminium level in patients from 3 microg/l to 38 microg/l. After excluding water, concentrate, dialysis fluid, drug intake, etc... as possible sources, we controlled the aluminium level in the glass bottle containing tri-sodium citrate. We noted the very high value of 35,300 microg/l. After replacing the glass bottles with polyvinylchloride bags with a negligible aluminium content, the serum aluminium levels returned back to normal. It is known that citrate chelates the aluminium present in the glass of bottles or vials.

  19. Citrate-permeable channels in the plasma membrane of cluster roots from white lupin.

    PubMed

    Zhang, Wen-Hao; Ryan, Peter R; Tyerman, Stephen D

    2004-11-01

    White lupin (Lupinus albus) is well adapted to phosphorus deficiency by developing cluster roots that release large amounts of citrate into the rhizosphere to mobilize the sparingly soluble phosphorus. To determine the mechanism underlying citrate release from cluster roots, we isolated protoplasts from different types of roots of white lupin plants grown in phosphorus-replete (+P) and phosphorus-deficient (-P) conditions and used the patch-clamp technique to measure the whole-cell currents flowing across plasma membrane of these protoplasts. Two main types of anion conductance were observed in protoplasts prepared from cluster root tissue: (1) an inwardly rectifying anion conductance (IRAC) activated by membrane hyperpolarization, and (2) an outwardly rectifying anion conductance (ORAC) that became more activated with membrane depolarization. Although ORAC was an outward rectifier, it did allow substantial inward current (anion efflux) to occur. Both conductances showed citrate permeability, with IRAC being more selective for citrate3- than Cl- (PCit/PCl = 26.3), while ORAC was selective for Cl- over citrate (PCl/PCit = 3.7). Both IRAC and ORAC were sensitive to the anion channel blocker anthracene-9-carboxylic acid. These currents were also detected in protoplasts derived from noncluster roots of -P plants, as well as from normal (noncluster) roots of plants grown with 25 microm phosphorus (+P). No differences were observed in the magnitude or frequency of IRAC and ORAC currents between the cluster roots and noncluster roots of -P plants. However, the IRAC current from +P plants occurred less frequently than in the -P plants. IRAC was unaffected by external phosphate, but ORAC had reduced inward current (anion efflux) when phosphate was present in the external medium. Our data suggest that IRAC is the main pathway for citrate efflux from white lupin roots, but ORAC may also contribute to citrate efflux.

  20. Citrate and renal calculi: an update

    NASA Technical Reports Server (NTRS)

    Pak, C. Y.

    1994-01-01

    Citrate is an inhibitor of the crystallization of stone-forming calcium salts. Hypocitraturia, frequently encountered in patients with nephrolithiasis, is therefore an important risk factor for stone formation. Potassium citrate provides physiological and physicochemical correction and inhibits new stone formation, not only in hypocitraturic calcium nephrolithiasis but also in uric acid nephrolithiasis. Inhibition of stone recurrence has now been validated by a randomized trial. Ongoing research has disclosed additional causes of hypocitraturia (sodium excess, low intestinal alkali absorption, but not primary citrate malabsorption). Moreover, new insights on potassium citrate action have been shown, notably that some of absorbed citrate escapes oxidation and contributes to the citraturic response, that ingestion with a meal does not sacrifice physiological or physicochemical action, that orange juice mimics but does not completely duplicate its actions, that potassium citrate may have a beneficial bone-sparing effect, that it may reduce stone fragments following ESWL, and that danger of aluminum toxicity is not great in subjects with functioning kidneys. Finally, the research on potassium citrate has led to two promising products, calcium citrate as an optimum calcium supplement and potassium-magnesium citrate which may be superior to potassium citrate in the management of stone disease.

  1. 21 CFR 184.1625 - Potassium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing...

  2. 21 CFR 184.1625 - Potassium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing...

  3. 21 CFR 184.1625 - Potassium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing...

  4. 21 CFR 184.1625 - Potassium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing citric acid with...

  5. 21 CFR 184.1625 - Potassium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Potassium citrate. 184.1625 Section 184.1625 Food... Specific Substances Affirmed as GRAS § 184.1625 Potassium citrate. (a) Potassium citrate (C6H5K3O7·H2O, CAS Reg. No. 006100-0905-096) is the potassium salt of citric acid. It is prepared by neutralizing...

  6. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... calcium carbonate. It occurs as a fine white, odorless powder and usually contains four moles of water per... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Calcium citrate. 184.1195 Section 184.1195 Food... GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095)...

  7. 21 CFR 184.1751 - Sodium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and....1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with sodium hydroxide or sodium...

  8. 21 CFR 184.1751 - Sodium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with...

  9. 21 CFR 184.1751 - Sodium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with...

  10. 21 CFR 184.1751 - Sodium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with...

  11. 21 CFR 184.1751 - Sodium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium citrate. 184.1751 Section 184.1751 Food and... Substances Affirmed as GRAS § 184.1751 Sodium citrate. (a) Sodium citrate (C6H5Na3O7·2H2O, CAS Reg. No. 68-0904-092) is the sodium salt of citric acid. It is prepared by neutralizing citric acid with...

  12. Melatonin-micronutrients Osteopenia Treatment Study (MOTS): a translational study assessing melatonin, strontium (citrate), vitamin D3 and vitamin K2 (MK7) on bone density, bone marker turnover and health related quality of life in postmenopausal osteopenic women following a one-year double-blind RCT and on osteoblast-osteoclast co-cultures

    PubMed Central

    Maria, Sifat; Swanson, Mark H.; Enderby, Larry T.; D'Amico, Frank; Enderby, Brianna; Samsonraj, Rebekah M.; Dudakovic, Amel; van Wijnen, Andre J.; Witt-Enderby, Paula A.

    2017-01-01

    This one-year double blind randomized control trial assessed the effects of nightly melatonin, strontium (citrate), vitamin D3 and vitamin K2 (MK7; MSDK) on bone mineral density (BMD) and quality of life (QOL) in postmenopausal osteopenic women (ages 49-75). Compared to placebo, MSDK treatment increased BMD in lumbar spine (4.3%) and left femoral neck (2.2%), with an upward trend for total left hip (p=0.069). MSDK increased serum P1NP levels and reduced bone turnover (CTx:P1NP). Psychometric analyses indicated that mood and sleep quality improved for the MSDK group. MSDK-exposed human mesenchymal stem cells (hMSCs) and human peripheral blood monocytes (hPBMCs) plated in transwells or layered demonstrated increases in osteoblastogenesis, decreases in osteoclastogenesis, increases in OPG (TNFRSF11B) and decreases in RANKL (TNFSF11) levels. In transwell osteoblasts, MSDK increased pERK1/2 (MAPK1/MAPK3) and RUNX2 levels; decreased ERK5 (MAPK7); and did not affect the expression of NFκB (NFKB1) and β1integrin (ITGB1). In layered osteoblasts, MSDK also decreased expression of the metabolic proteins PPARγ (PPARG) and GLUT4 (SLC2A4). In adipose-derived human MSCs, MSDK induced osteoblastogenesis. These findings provide both clinical and mechanistic support for the use of MSDK for the prevention or treatment of osteopenia, osteoporosis or other bone-related diseases. PMID:28130552

  13. Renal tissue citrate: independence from citrate utilization, reabsorption, and pH.

    PubMed

    Anaizi, N H; Cohen, J J; Black, A J; Wertheim, S J

    1986-09-01

    During alkalosis in vivo, renal tissue [citrate] [( citrate]t) increases and citrate reabsorption (Tcit) and utilization (Qcit) simultaneously decrease. The decrease in Qcit is interpreted to cause the increased [citrate]t, which in turn decreases Tcit X Renal citrate handling and [citrate]t could be regulated by other mechanisms, since alkalosis changes [substrate] and [H+] in extracellular (ECF) and intracellular (ICF) fluid. Also, since high plasma [citrate] decreases ionized [Ca2+] (Cai), it is not possible to determine in vivo whether there is a maximum for Tcit or Qcit and whether change in extracellular fluid (delta ECF) pH affects these maxima. We perfused the substrate-limited isolated rat kidney for either 110 (n = 36) or 50 min (n = 44) at pH 7.2, 7.4, or 7.6; pH was changed by varying [HCO3-]; Cai was held constant at approximately 2.5 meq/liter. When citrate was the only substrate available in a Krebs-Ringer-HCO3 perfusate containing 6% substrate-free albumin, both Qcit and Tcit had maximal rates: Qcit much greater than Tcit; at pH 7.6, Qcit and Tcit were significantly reduced below their values at pH 7.2 or 7.4. In contrast to in vivo observations, [citrate]t was not significantly increased at high ECF pH. To test whether [citrate]t in the perfused kidney can increase in alkalosis, 11 additional perfusions were done in the presence of glucose plus lactate plus malate but without added citrate: [citrate]t = 0.6 mumol X g-1 at pH 7.6 and 0.3 mumol X g-1 at pH 7.2 (P less than 0.01); no citrate was detectable in the perfusate, and urinary citrate excretion was negligible. Thus, in the isolated rat kidney, an increase in [citrate]t occurred in alkalosis and was derived from precursors and not from citrate in the ECF. Overall, when only citrate was available to the isolated kidney during alkalosis, a significant rise in [citrate]t did not occur, although Vmax for Tcit and Qcit decreased. These effects of alkalosis on Tcit are consistent with observations

  14. Studies on the reduction of aortic calcification by alkali citrates in an ex vivo tissue preparation in the rat.

    PubMed

    Schick, C H; Schwille, P O

    1993-08-01

    The effect of orally administered alkali citrates on the calcification of arterial vessel was studied in the rat. Freshly dissected aortic segments were placed in Millipore diffusion chambers and grafted intraperitoneally. Within 21 days calcification of the media had developed. Under treatment with 2.1 mmol citrate per animal and day a significant decrease in histologically detectable calcification areas occurred, as assessed by greatest thickness and longitudinal expansion. This effect was more pronounced with potassium citrate and potassium sodium citrate, and less marked with sodium citrate. The calcium and phosphorus content of aortic tissue remained unchanged, but magnesium increased significantly. The spheroid particles deposited in the media were characterized in more detail by electron microscopy and elemental microanalysis, X-ray diffraction, and determination of the molar calcium-phosphorus ratio. The combined data suggest that in the model selected for studying biocalcification not mature hydroxyapatite but some precursor of this substance is deposited, and that in animals receiving alkali citrate treatment deposition of amorphous calcium phosphate is likely. It is concluded that in the ex vivo aortic wall preparation oral alkali citrates a) bring about a reduction in calcification areas in the media layer, b) impair the maturation of hydroxyapatite and its deposition in the arterial tissue; c) promote the accumulation of magnesium. Whether these results are of significance for the calcification of arteries in situ and treatment regimens is unknown.

  15. Leg citrate metabolism at rest and during exercise in relation to diet and substrate utilization in man.

    PubMed

    Jansson, E; Kaijser, L

    1984-10-01

    Previously we have demonstrated a lower rate of carbohydrate utilization in skeletal muscle after a fat than after a carbohydrate rich diet both at rest and during exercise. To test the hypothesis of citrate as a regulator of glycolysis (1) arterial-femoral venous (a-fv) differences for oxygen, citrate, pyruvate and lactate and (2) muscle citrate and glucose-6-phosphate (G-6-P) were determined at rest and after 5 and 25 min of submaximal bicycle exercise. Citrate release and muscle citrate concentration were higher after fat than after carbohydrate diet at rest and 5 min exercise, but did not differ between diets at 25 min exercise. Lactate release and muscle lactate concentration were lower after fat diet at 5 and 25 min exercise. Pyruvate release at 5 min exercise was higher after fat diet. The G-6-P concentration was higher at rest, insignificantly higher after 5 min exercise and lower at 25 min exercise after the fat diet. The findings support the notion that at rest and 5 min exercise fat diet induced inhibition of glycolysis might be mediated through increased intramuscular citrate acting on phosphofructokinase. In addition, the greater pyruvate release at 5 min exercise after fat diet in spite of a smaller lactate release, indicates a decreased pyruvate dehydrogenase activity and/or NADH to NAD ratio after fat diet. The inhibition of glycolysis at 25 min exercise after fat diet on the other hand does not seem to be citrate mediated.

  16. 21 CFR 184.1386 - Isopropyl citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Specific Substances Affirmed as GRAS § 184.1386 Isopropyl citrate. (a) Isopropyl citrate is a mixture of the mono-, di-, and triisopropyl esters of citric acid. It is prepared by esterifying citric acid with... practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human...

  17. 21 CFR 184.1851 - Stearyl citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Substances Affirmed as GRAS § 184.1851 Stearyl citrate. (a) Stearyl citrate is a mixture of the mono-, di-, and tristearyl esters of citric acid. It is prepared by esterifying citric acid with stearyl alcohol... practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human...

  18. 21 CFR 184.1386 - Isopropyl citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Specific Substances Affirmed as GRAS § 184.1386 Isopropyl citrate. (a) Isopropyl citrate is a mixture of the mono-, di-, and triisopropyl esters of citric acid. It is prepared by esterifying citric acid with... practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a direct human...

  19. 21 CFR 184.1195 - Calcium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Specific Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with calcium hydroxide or calcium carbonate. It occurs as a fine white, odorless powder...

  20. 21 CFR 184.1851 - Stearyl citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Specific Substances Affirmed as GRAS § 184.1851 Stearyl citrate. (a) Stearyl citrate is a mixture of the mono-, di-, and tristearyl esters of citric acid. It is prepared by esterifying citric acid with... manufacturing practice. The affirmation of this ingredient as generally recognized as safe (GRAS) as a...

  1. 21 CFR 184.1911 - Triethyl citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Specific Substances Affirmed as GRAS § 184.1911 Triethyl citrate. (a) Triethyl citrate (C12H20O7, CAS Reg. No. 77-93-0) is the triethyl ester of citric acid. It is prepared by esterifying citric acid with... recognized as safe (GRAS) as a direct human food ingredient is based upon the following current...

  2. 21 CFR 184.1911 - Triethyl citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Specific Substances Affirmed as GRAS § 184.1911 Triethyl citrate. (a) Triethyl citrate (C12H20O7, CAS Reg. No. 77-93-0) is the triethyl ester of citric acid. It is prepared by esterifying citric acid with... recognized as safe (GRAS) as a direct human food ingredient is based upon the following current...

  3. [Development of identification method for isopropyl citrate].

    PubMed

    Furusho, Noriko; Ohtsuki, Takashi; Tatebe-Sasaki, Chiye; Kubota, Hiroki; Sato, Kyoko; Akiyama, Hiroshi

    2014-01-01

    In Japan's Specification and Standards for Food Additive, 8th edition, two identification tests involving isopropyl citrate for detecting isopropyl alcohol and citrate are stipulated. However, these identification tests use mercury compound, which is toxic, or require a time-consuming pretreatment process. To solve these problems, an identification test method using GC-FID for detecting isopropyl alcohol was developed. In this test, a good linearity was observed in the range of 0.1-40 mg/mL of isopropyl alcohol. While investigating the pretreatment process, we found that isopropyl alcohol could be detected using GC-FID in the distillation step only, without involving any reflux step. The study also showed that the citrate moiety of isopropyl citrate was identified using the solution remaining after conducting the distillation of isopropyl alcohol. The developed identification tests for isopropyl citrate are simple and use no toxic materials.

  4. Citrate anticoagulation: Are blood donors donating bone?

    PubMed

    Bialkowski, Walter; Bruhn, Roberta; Edgren, Gustaf; Papanek, Paula

    2016-10-01

    An estimated 2.4 million volunteer apheresis blood donation procedures were performed in the United States in 2010, and increases in the proportion of transfused blood products derived from apheresis blood collections have been consistently reported. Anticoagulation is required during apheresis and is achieved with citrate. Donor exposure to citrate causes an acute physiological response to maintain serum mineral homeostasis. Some data are available on the sequelae of this acute response in the days and weeks following exposure, raising questions about bone mineral density in regular apheresis donors. New research is emerging that addresses the potential long-term health outcomes of repeated citrate exposure. This article reviews the acute physiological response to citrate anticoagulation in volunteer blood donors, presents contrasting perspectives on the potential effects of citrate exposure on bone density, and identifies key knowledge gaps in our understanding of long-term health outcomes in apheresis donors. J. Clin. Apheresis 31:459-463, 2016. © 2015 Wiley Periodicals, Inc.

  5. Incompatibility of Contrast Medium and Trisodium Citrate

    SciTech Connect

    Delcour, Christian Bruninx, Guy

    2013-02-15

    To test the compatibility of trisodium citrate, a catheter lock solution, with iodinated contrast medium. Iohexol, iobitridol, iodixanol, ioxaglate, ioxithalamate, iomeprol, and iopromide were tested. In all tests, 2 ml of contrast medium were mixed with 2 ml of trisodium citrate solution. Iodixanol and ioxaglate provoked a highly viscous gluelike precipitation when mixed with trisodium citrate. A brief transient precipitate was observed with iohexol, iomeprol, and ioxithalamate. Permanent precipitation occurred with iobitridol and iopromide. One must be aware of the potential for precipitation when contrast medium is mixed with trisodium citrate solution. Before trisodium citrate solution is injected, the catheter should be thoroughly flushed with saline if a contrast medium has previously been injected through it.

  6. Fate of uranyl in a quaternary system composed of uranyl, citrate, goethite, and Pseudomonas fluorescens.

    PubMed

    Bencheikh-Latmani, Rizlan; Leckie, James O; Bargar, John R

    2003-08-15

    This study investigated the partitioning of uranyl within a quaternary system made up of uranyl, citrate, goethite, and the bacterium Pseudomonas fluorescens. In the absence of cells, uranyl was sorbed to goethite as a complex involving surface groups and/or citrate. Measurements of the evolution of CO2 indicated that the addition of bacterial cells lead to the gradual biodegradation of citrate. Throughout the biodegradation process, uranyl remained sorbed to the insoluble fraction comprised of goethite and cells. EXAFS (Extended X-ray Absorption Fine Structure) measurements showed that bacterial cells outcompeted goethite for uranyl under the experimental conditions and caused the repartitioning of uranyl from goethite to cell matter, independently from citrate degradation. Citrate degradation caused further release of uranyl from goethite surfaces, followed by subsequent association of uranyl with cells. At long equilibration times (3 months), cell lysis and phosphate release resulted in the precipitation of an autunite-like phase. This work suggests that bacterial degradation of uranyl-complexing ligands in contaminated subsurface media containing iron oxides should not necessarily lead to an increase in the mobility of uranyl.

  7. [Butamyrate citrate in cough controlling].

    PubMed

    Płusa, Tadeusz

    2013-12-01

    The cough as one of the main symptoms of respiratory infections in the most cases is carried out in children and adults using preparations without a prescription (OTC--over-the-counter) and cold medications (CCMs). Their efficacy and safety have not been fully confirmed. In turn, the administration of drugs that inhibit cough by acting on the central nervous system requires adherence to dosage. Codeine as the main standard of the cough suppressants is not always effective. Used for many years butamyrate citrate is highly effective and complete safety. The number and quality of the side effects after application of this preparation is small and is not limited especially in pediatrics. Conducted research on new drugs that inhibit cough are very promising.

  8. The Application of Heat and Corrosion Resistant Phosphate Coatings Under Steam Pressure

    DTIC Science & Technology

    1974-03-01

    SUPPLEMENTARY NorEs 19. KEY ’WORDS (Continue on reverae aide if neceasary and Identify by block number) 1. Phosphate coatings 4 . Corrosion resistance 2...Manganese phosphate 5. Pressure Vessel 3 . Heat resistance 20. ABSTRACT (Continue on reveae aide it necesary and Identify by bloch number) Processing...2 Manganese Phosphate Coatings Applied in a 15 Conventional Bath with and without Mangan- ese Citrate 3 Me ganese Phosphate Coatings Applied in a 18

  9. A citrate-binding site in calmodulin.

    PubMed

    Neufeld, T; Eisenstein, M; Muszkat, K A; Fleminger, G

    1998-01-01

    Calmodulin (CaM) is a major Ca2+ messenger which, upon Ca2+ activation, binds and activates a number of target enzymes involved in crucial cellular processes. The dependence on Ca2+ ion concentration suggests that CaM activation may be modulated by low-affinity Ca2+ chelators. The effect on CaM structure and function of citrate ion, a Ca2+ chelator commonly found in the cytosol and the mitochondria, was therefore investigated. A series of structural and biochemical methods, including tryptic mapping, immunological recognition by specific monoclonal antibodies, CIDNP-NMR, binding to specific ligands and association with radiolabeled citrate, showed that citrate induces conformational modifications in CaM which affect the shape and activity of the protein. These changes were shown to be associated with the C-terminal lobe of the molecule and involve actual binding of citrate to CaM. Analyzing X-ray structures of several citrate-binding proteins by computerized molecular graphics enabled us to identify a putative citrate-binding site (CBS) on the CaM molecule around residues Arg106-His107. Owing to the tight proximity of this site to the third Ca(2+)-binding loop of CaM, binding of citrate is presumably translated into changes in Ca2+ binding to site III (and indirectly to site IV). These changes apparently affect the structural and biochemical properties of the conformation-sensitive protein.

  10. Regulation of Renal Citrate Metabolism by Bicarbonate Ion and pH: Observations in Tissue Slices and Mitochondria*

    PubMed Central

    Simpson, David P.

    1967-01-01

    The effect of acid-base balance on the oxidation and utilization of citrate and other organic acids has been studied in tissue slices and isolated kidney mitochondria. The results show that: 1) With bicarbonate-buffered media, citrate oxidation and utilization are inhibited in slices of renal cortex and in kidney mitochondria when [HCO3-] and pH are increased within the physiologic range (pH 7.0 to 7.8; 10 to 60 μmoles HCO3- per ml). When phosphate or Tris buffers are used, no comparable effect on citrate oxidation occurs when pH is varied. 2) This effect is not demonstrable in heart or liver slices when a physiologic buffer is used. 3) α-Ketoglutarate utilization is inhibited in slices of renal cortex under similar conditions. Pyruvate and L-malate utilization are not inhibited in slices or mitochondria. 4) Citrate content in slices of renal cortex incubated with a high [HCO3-] is considerably greater than the concentration found with a low [HCO3-] in the medium. This effect is not duplicated by pH change in a nonbicarbonate buffer system. In mitochondria citrate content is also increased markedly at high bicarbonate concentrations. 5) The kinetic characteristics of the inhibition of citrate oxidation are those of a competitive type of inhibition. 6) When pH was varied with a constant [HCO3-] in the media, citrate oxidation was inhibited by increasing pH in slices of renal cortex but not in mitochondria. On the other hand, when [HCO3-] was increased without change in pH, no decrease in citrate oxidation occurred in slices, but a marked inhibitory effect was found when mitochondria were used. From a comparison of these results with those previously obtained in intact animal experiments, we conclude that the inhibition of citrate oxidation caused by increasing pH and [HCO3-] in slices of renal cortex and kidney mitochondria is an in vitro representation of the inhibition of citrate reabsorption in the nephron that occurs in metabolic alkalosis. Thus, citrate

  11. 21 CFR 184.1307c - Ferrous citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... the reaction of sodium citrate with ferrous sulfate or by direct action of citric acid on iron filings... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Ferrous citrate. 184.1307c Section 184.1307c Food... Specific Substances Affirmed as GRAS § 184.1307c Ferrous citrate. (a) Ferrous citrate (iron (II)...

  12. 21 CFR 184.1307c - Ferrous citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... the reaction of sodium citrate with ferrous sulfate or by direct action of citric acid on iron filings... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Ferrous citrate. 184.1307c Section 184.1307c Food... Specific Substances Affirmed as GRAS § 184.1307c Ferrous citrate. (a) Ferrous citrate (iron (II)...

  13. 21 CFR 184.1307c - Ferrous citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... the reaction of sodium citrate with ferrous sulfate or by direct action of citric acid on iron filings... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Ferrous citrate. 184.1307c Section 184.1307c Food... Specific Substances Affirmed as GRAS § 184.1307c Ferrous citrate. (a) Ferrous citrate (iron (II)...

  14. 21 CFR 184.1307c - Ferrous citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... the reaction of sodium citrate with ferrous sulfate or by direct action of citric acid on iron filings... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Ferrous citrate. 184.1307c Section 184.1307c Food... Specific Substances Affirmed as GRAS § 184.1307c Ferrous citrate. (a) Ferrous citrate (iron (II)...

  15. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  16. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  17. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Iron ammonium citrate. 172.430 Section 172.430... CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in... human consumption so that the level of iron ammonium citrate does not exceed 25 parts per million...

  18. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron ammonium citrate. 172.430 Section 172.430 Food... Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in... consumption so that the level of iron ammonium citrate does not exceed 25 parts per million (0.0025...

  19. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron ammonium citrate. 573.560 Section 573.560... Additive Listing § 573.560 Iron ammonium citrate. Iron ammonium citrate may be safely used in animal feed... consumption so that the level of iron ammonium citrate does not exceed 25 parts per million (0.0025...

  20. 21 CFR 184.1307c - Ferrous citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... citrate with ferrous sulfate or by direct action of citric acid on iron filings. (b) The ingredient must... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ferrous citrate. 184.1307c Section 184.1307c Food... GRAS § 184.1307c Ferrous citrate. (a) Ferrous citrate (iron (II) citrate, (C6H6FeO7), CAS Reg....

  1. Effect of ranitidine bismuth citrate on postprandial plasma gastrin and pepsinogens.

    PubMed Central

    Fraser, A G; Lam, W M; Luk, Y W; Sercombe, J; Sawyerr, A M; Hudson, M; Samloff, I M; Pounder, R E

    1993-01-01

    Ranitidine bismuth citrate was compared with an equipotent dose of ranitidine, to determine whether the former, by an anti-Helicobacter pylori activity, would counteract the rise of gastrin resulting from ranitidine's gastric acid antisecretory activity. Twenty four men with duodenal ulcers were studied before and on the 8th day of dosing with either ranitidine bismuth citrate 800 mg twice daily or ranitidine 300 mg twice daily (double blind, randomised, parallel groups). Fasting and postprandial plasma gastrin and plasma pepsinogen I and II concentrations were measured, and a 13C-urea breath test was performed before and on the 8th day of dosing. The 13C-urea breath tests were positive in 21 patients before dosing and remained positive in nine of nine of the ranitidine dosed patients, whereas only two of 12 patients treated with ranitidine bismuth citrate remained positive. The expected rise in meal stimulated plasma gastrin with ranitidine was seen in the 12 patients who received ranitidine but, despite suppression of H pylori urease activity in 10 of 12 patients taking ranitidine bismuth citrate, there was no attenuation of the meal stimulated gastrin rise. There was no significant difference in the mean derived (4 hour) plasma pepsinogen I and II concentrations after dosing with ranitidine or ranitidine bismuth citrate. PMID:8472980

  2. Phosphate binders in chronic kidney disease: a systematic review of recent data.

    PubMed

    Floege, Jürgen

    2016-06-01

    Hyperphosphatemia is common in chronic kidney disease (CKD) and is treated by dietary measures, dialysis techniques and/or phosphate binders. For the present review PubMed was searched for new publications on phosphate binders appearing between January 2010 and October 2015. This review summarizes the latest information on non-pharmacological measures and their problems in lowering phosphate in CKD patients, effects of phosphate binders on morbidity and mortality, adherence to phosphate binder therapy as well as new information on specific aspects of the various phosphate binders on the market: calcium acetate, calcium carbonate, magnesium-containing phosphate binders, polymeric phosphate binders (sevelamer, bixalomer, colestilan), lanthanum carbonate, ferric citrate, sucroferric oxyhydroxide, aluminum-containing phosphate binders, and new compounds in development. The review also briefly covers the emerging field of drugs targeting intestinal phosphate transporters.

  3. Citrate, a specific substrate for the isolation of Clostridium sphenoides.

    PubMed Central

    Walther, R; Hippe, H; Gottschalk, G

    1977-01-01

    With a medium containing citrate as the carbon and energy source, 10 clostridial strains were isolated from various mud samples. Characterization of these strains revealed that they all belonged to the same species, Clostridium sphenoides. Strains of this organism obtained from culture collections were also able to grow citrate, whereas 15 other clostridial species tested were not. Citrate was fermented by C. sphenoides to acetate, ethanol, carbon dioxide, and hydrogen. Experiments with stereospecifically 14C-labeled citrate indicated that citrate lyase was involved in citrate degradation. Images PMID:869540

  4. Vibrational study of tamoxifen citrate polymorphism

    NASA Astrophysics Data System (ADS)

    Gamberini, M. C.; Baraldi, C.; Tinti, A.; Palazzoli, F.; Ferioli, V.

    2007-09-01

    The trans isomer of ( Z)-2-[ p-(1,2-diphenyl-butenyl)phenoxy]- N, N-dimethyletylamine (tamoxifen) is well known for its endocrine activity as an antiestrogenic agent. Its citrate salt, a widely used pharmaceutical agent, appears in three main polymorphic forms, two of which are well known (I and II) and another form not yet well evidenced. A vibrational study has been conducted for identifying the two known polymorphic forms of tamoxifen citrate (I and II) and for characterising the other form (form III) examined in this study. Other techniques for the characterization of the different polymorphs, such as XRDP, have been used.

  5. Organically modified porous hydroxyapatites: A comparison between alkylphosphonate grafting and citrate chelation

    SciTech Connect

    El-Hammari, L.; Marroun, H.; Laghzizil, A.; Saoiabi, A.; Roux, C.; Livage, J.; Coradin, T.

    2008-04-15

    Two alternative methods to prepare organically modified porous hydroxyapatites following a 'one pot' approach were compared. The partial substitution of inorganic phosphates by alkylphosphonates leads to mesoporous materials with high specific surface area (>200 m{sup 2} g{sup -1}). The incorporation of the organic moieties within the hydroxyapatite structure is confirmed by Infra-red and solid-state NMR spectroscopy and depends on the nature of the alkyl chain. However, it induces a significant loss of the material crystallinity. In contrast, the introduction of citrate, a calcium-chelating agent, to the precursor solution does not improve the material specific surface area but allows a better control of the hydroxyapatite structure, both in terms of crystallinity and pore size distribution. - Graphical abstract: Evolution of pore size distribution of hydroxyapatite (HAp) after alkylphosphonate grafting (20% TPOH) or citrate addition (c-HAp) demonstrates the formation of organically modified mesoporous materials.

  6. Phosphate salts

    MedlinePlus

    ... sodium if you have heart disease. Fluid retention (edema): Avoid using phosphate salts that contain sodium if ... heart failure, or other conditions that can cause edema. High levels of calcium in the blood (hypercalcemia): ...

  7. Evidence that Osteoblasts are Specialized Citrate-producing Cells that Provide the Citrate for Incorporation into the Structure of Bone

    PubMed Central

    Franklin, Renty B.; Chellaiah, Meena; Zou, Jing; Reynolds, Mark A.; Costello, Leslie C.

    2015-01-01

    Citrate is a major component of bone in all vertebrates, but its implications in bone have remained largely unknown. Recent studies identified that citrate is incorporated into the structure of the hydroxyapatite nanocrystal/collagen complex; and is essential for the important biomechanical properties of bone. This raises the important question, “What is the source of citrate for incorporation into bone?”; A question that heretofore had remained unresolved. Studies in this report were designed to determine the plausibility of our concept that the osteoblasts are specialized citrate-producing cells, which provide the citrate that is incorporated into the structure of bone; and that osteogenic differentiation of mesenchyme cells leads to the development of the citrate-producing osteoblasts. The results demonstrated that primary human osteoblasts exhibit the capability of citrate-production. Undifferentiated mesenchyme cells do not exhibit the capability of citrate production; and osteogenic differentiation results in citrate-producing osteoblasts. The up-regulation of zinc uptake transporter ZIP1 is essential for the manifestation of the citrate-producing capability of the osteoblasts. We determined that osteoblast transport of citrate from plasma is not a likely source of citrate in bone. Thus, this study establishes for the first time that the osteoblasts are specialized citrate-producing cells that provide the citrate for incorporation into the structure of bone; and that mesenchyme cell osteogenesis leads to differentiated citrate-producing osteoblasts. This is a new understanding; which must include the osteogenic development of citrate-producing osteoblasts, and the process of “citration” in concert with mineralization during bone formation. It also provides a new understanding of the role of bone in the homeostatic maintenance of plasma citrate concentration. PMID:25745519

  8. Acute and 3-month effects of microcrystalline hydroxyapatite, calcium citrate and calcium carbonate on serum calcium and markers of bone turnover: a randomised controlled trial in postmenopausal women.

    PubMed

    Bristow, Sarah M; Gamble, Greg D; Stewart, Angela; Horne, Lauren; House, Meaghan E; Aati, Opetaia; Mihov, Borislav; Horne, Anne M; Reid, Ian R

    2014-11-28

    Ca supplements are used for bone health; however, they have been associated with increased cardiovascular risk, which may relate to their acute effects on serum Ca concentrations. Microcrystalline hydroxyapatite (MCH) could affect serum Ca concentrations less than conventional Ca supplements, but its effects on bone turnover are unclear. In the present study, we compared the acute and 3-month effects of MCH with conventional Ca supplements on concentrations of serum Ca, phosphate, parathyroid hormone and bone turnover markers. We randomised 100 women (mean age 71 years) to 1 g/d of Ca as citrate or carbonate (citrate-carbonate), one of two MCH preparations, or a placebo. Blood was sampled for 8 h after the first dose, and after 3 months of daily supplementation. To determine whether the acute effects changed over time, eight participants assigned to the citrate dose repeated 8 h of blood sampling at 3 months. There were no differences between the citrate and carbonate groups, or between the two MCH groups, so their results were pooled. The citrate-carbonate dose increased ionised and total Ca concentrations for up to 8 h, and this was not diminished after 3 months. MCH increased ionised Ca concentrations less than the citrate-carbonate dose; however, it raised the concentrations of phosphate and the Ca-phosphate product. The citrate-carbonate and MCH doses produced comparable decreases in bone resorption (measured as serum C-telopeptide (CTX)) over 8 h and bone turnover (CTX and procollagen type-I N-terminal propeptide) at 3 months. These findings suggest that Ca preparations, in general, produce repeated sustained increases in serum Ca concentrations after ingestion of each dose and that Ca supplements with smaller effects on serum Ca concentrations may have equivalent efficacy in suppressing bone turnover.

  9. Physicochemical action of potassium-magnesium citrate in nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Pak, C. Y.; Koenig, K.; Khan, R.; Haynes, S.; Padalino, P.

    1992-01-01

    Effect of potassium-magnesium citrate on urinary biochemistry and crystallization of stone-forming salts was compared with that of potassium citrate at same dose of potassium in five normal subjects and five patients with calcium nephrolithiasis. Compared to the placebo phase, urinary pH rose significantly from 6.06 +/- 0.27 to 6.48 +/- 0.36 (mean +/- SD, p less than 0.0167) during treatment with potassium citrate (50 mEq/day for 7 days) and to 6.68 +/- 0.31 during therapy with potassium-magnesium citrate (containing 49 mEq K, 24.5 mEq Mg, and 73.5 mEq citrate per day). Urinary pH was significantly higher during potassium-magnesium citrate than during potassium citrate therapy. Thus, the amount of undissociated uric acid declined from 118 +/- 61 mg/day during the placebo phase to 68 +/- 54 mg/day during potassium citrate treatment and, more prominently, to 41 +/- 46 mg/day during potassium-magnesium citrate therapy. Urinary magnesium rose significantly from 102 +/- 25 to 146 +/- 37 mg/day during potassium-magnesium citrate therapy but not during potassium citrate therapy. Urinary citrate rose more prominently during potassium-magnesium citrate therapy (to 1027 +/- 478 mg/day from 638 +/- 252 mg/day) than during potassium citrate treatment (to 932 +/- 297 mg/day). Consequently, urinary saturation (activity product) of calcium oxalate declined significantly (from 1.49 x 10(-8) to 1.03 x 10(-8) M2) during potassium-magnesium citrate therapy and marginally (to 1.14 x 10(-8) M2) during potassium citrate therapy.(ABSTRACT TRUNCATED AT 250 WORDS).

  10. 21 CFR 73.2110 - Bismuth citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the...

  11. 21 CFR 73.2110 - Bismuth citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the...

  12. 21 CFR 73.2110 - Bismuth citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the...

  13. 21 CFR 73.2110 - Bismuth citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the...

  14. 21 CFR 73.2110 - Bismuth citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... restrictions. The color additive bismuth citrate may be safely used in cosmetics intended for coloring hair on..., eyebrows, or hair on parts of the body other than the scalp. (d) Labeling. (1) The label of the color... abraded scalp. Do not use to color eyelashes, eyebrows, or hair on parts of the body other than the...

  15. 21 CFR 582.5449 - Manganese citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Manganese citrate. 582.5449 Section 582.5449 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  16. 21 CFR 582.5195 - Calcium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  17. 21 CFR 582.5449 - Manganese citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Manganese citrate. 582.5449 Section 582.5449 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  18. 21 CFR 582.5195 - Calcium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  19. 21 CFR 582.5449 - Manganese citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Manganese citrate. 582.5449 Section 582.5449 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  20. 21 CFR 582.5449 - Manganese citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Manganese citrate. 582.5449 Section 582.5449 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  1. 21 CFR 582.5195 - Calcium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  2. 21 CFR 582.5195 - Calcium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  3. 21 CFR 582.5449 - Manganese citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Manganese citrate. 582.5449 Section 582.5449 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  4. 21 CFR 582.5195 - Calcium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS SUBSTANCES GENERALLY RECOGNIZED AS SAFE Nutrients and/or...

  5. 14 N NQR spectrum of sildenafil citrate

    NASA Astrophysics Data System (ADS)

    Stephenson, David; Singh, Nadia

    2015-04-01

    The 14N nuclear quadrupole resonance (NQR) spectrum of sildenafil citrate tablets has been recorded allowing the quadrupole coupling constants and asymmetry parameters of all six unique nitrogen atoms in its structure to be determined. A density function calculation gives results that are largely in agreement with the experimental values.

  6. Citrate as a siderophore in Bradyrhizobium japonicum.

    PubMed Central

    Guerinot, M L; Meidl, E J; Plessner, O

    1990-01-01

    Under iron-limiting conditions, many bacteria secrete ferric iron-specific ligands, generically termed siderophores, to aid in the sequestering and transport of iron. One strain of the nitrogen-fixing soybean symbiont Bradyrhizobium japonicum, 61A152, was shown to produce a siderophore when 20 B. japonicum strains were screened with all six chemical assays commonly used to detect such production. Production by strain 61A152 was detected via the chrome azurol S assay, a general test for siderophores which is independent of siderophore structure. The iron-chelating compound was neither a catechol nor a hydroxamate and was ninhydrin negative. It was determined to be citric acid via a combination of thin-layer chromatography and high-voltage paper electrophoresis; this identification was verified by a specific enzymatic assay for citric acid. The inverse correlation which was observed between citric acid release and the iron content of the medium suggested that ferric citrate could serve as an iron source. This was confirmed via growth and transport assays. Exogenously added ferric citrate could be used to overcome iron starvation, and iron-deficient cells actively transported radiolabeled ferric citrate. These results, taken together, indicate a role for ferric citrate in the iron nutrition of this strain, which has been shown to be an efficient nitrogen-fixing strain on a variety of soybean cultivars. PMID:2140566

  7. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron-choline citrate complex. 573.580 Section...

  8. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Iron-choline citrate complex. 573.580 Section...

  9. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Iron-choline citrate complex. 573.580 Section...

  10. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iron-choline citrate complex. 573.580 Section...

  11. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Iron-choline citrate complex. 172.370 Section 172... Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline citrate complex made by reacting... source of iron in foods for special dietary use....

  12. 21 CFR 172.430 - Iron ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Iron ammonium citrate. 172.430 Section 172.430... ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Anticaking Agents § 172.430 Iron ammonium citrate. Iron ammonium citrate may be safely used in food in accordance with the...

  13. 21 CFR 573.580 - Iron-choline citrate complex.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Iron-choline citrate complex. 573.580 Section 573... Food Additive Listing § 573.580 Iron-choline citrate complex. Iron-choline citrate complex made by... used as a source of iron in animal feed....

  14. 21 CFR 520.622b - Diethylcarbamazine citrate syrup.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section... Diethylcarbamazine citrate syrup. (a)(1) Specifications. Each milliliter of syrup contains 60 milligrams of diethylcarbamazine citrate. (2) Sponsor. See No. 053501 in § 510.600(c) of this chapter. (3) Conditions of use....

  15. 21 CFR 520.622b - Diethylcarbamazine citrate syrup.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section... Diethylcarbamazine citrate syrup. (a)(1) Specifications. Each milliliter of syrup contains 60 milligrams of diethylcarbamazine citrate. (2) Sponsor. See No. 053501 in § 510.600(c) of this chapter. (3) Conditions of use....

  16. 21 CFR 520.622b - Diethylcarbamazine citrate syrup.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate syrup. 520.622b Section... Diethylcarbamazine citrate syrup. (a)(1) Specifications. Each milliliter of syrup contains 60 milligrams of diethylcarbamazine citrate. (2) Sponsor. See No. 053501 in § 510.600(c) of this chapter. (3) Conditions of use....

  17. 21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate, oxibendazole chewable... § 520.623 Diethylcarbamazine citrate, oxibendazole chewable tablets. (a) Specifications. Each tablet contains either 60, 120, or 180 milligrams of diethylcarbamazine citrate with 45, 91, or 136 milligrams...

  18. 21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate, oxibendazole chewable... § 520.623 Diethylcarbamazine citrate, oxibendazole chewable tablets. (a) Specifications. Each tablet contains either 60, 120, or 180 milligrams of diethylcarbamazine citrate with 45, 91, or 136 milligrams...

  19. 21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate, oxibendazole chewable... § 520.623 Diethylcarbamazine citrate, oxibendazole chewable tablets. (a) Specifications. Each tablet contains either 60, 120, or 180 milligrams of diethylcarbamazine citrate with 45, 91, or 136 milligrams...

  20. 21 CFR 520.622d - Diethylcarbamazine citrate capsules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate capsules. 520.622d... Diethylcarbamazine citrate capsules. (a) Specifications. Each capsule contains 12.5, 50, 200, or 400 milligrams (mg) diethylcarbamazine citrate. (b) Sponsor. See No. 011014 in § 510.600(c) of this chapter. (c) Conditions of use...

  1. Effect of trisodium citrate concentration and cooking time on the physicochemical properties of pasteurized process cheese.

    PubMed

    Shirashoji, N; Jaeggi, J J; Lucey, J A

    2006-01-01

    The effects of the concentration of trisodium citrate (TSC) emulsifying salt (0.25 to 2.75%) and holding time (0 to 20 min) on the textural, rheological, and microstructural properties of pasteurized process Cheddar cheese were studied using a central composite rotatable design. The loss tangent parameter (from small amplitude oscillatory rheology), extent of flow (derived from the University of Wisconsin Meltprofiler), and melt area (from the Schreiber test) all indicated that the meltability of process cheese decreased with increased concentration of TSC and that holding time led to a slight reduction in meltability. Hardness increased as the concentration of TSC increased. Fluorescence micrographs indicated that the size of fat droplets decreased with an increase in the concentration of TSC and with longer holding times. Acid-base titration curves indicated that the buffering peak at pH 4.8, which is due to residual colloidal calcium phosphate, decreased as the concentration of TSC increased. The soluble phosphate content increased as concentration of TSC increased. However, the insoluble Ca decreased with increasing concentration of TSC. The results of this study suggest that TSC chelated Ca from colloidal calcium phosphate and dispersed casein; the citrate-Ca complex remained trapped within the process cheese matrix. Increasing the concentration of TSC helped to improve fat emulsification and casein dispersion during cooking, both of which probably helped to reinforce the structure of process cheese.

  2. Pharmacokinetics of bismuth and ranitidine following multiple doses of ranitidine bismuth citrate

    PubMed Central

    KOCH, K M; KERR, B M; GOODING, A E; DAVIS, I M

    1996-01-01

    The pharmacokinetics of bismuth and ranitidine derived from oral doses of ranitidine bismuth citrate 800 mg given twice daily for 28 days were examined in this double-blind, placebo-controlled, parallel-group study in 27 healthy subjects. Bismuth accumulation in plasma reflected its multicompartmental disposition, achieving the majority of predicted steady state within 14–28 days. Bismuth absorption from ranitidine bismuth citrate is limited (<0.5% of the dose), and bismuth elimination is predominantly renal secretion. Peak plasma concentrations did not exceed 19 ng ml−1, remaining well below those associated with bismuth toxicity. Bismuth was measurable at low concentrations in plasma and urine for up to 5 months after the last dose. Plasma bismuth concentration-time data and urinary excretion data were best described by separate multicompartmental models, with terminal half-lives averaging 21 days and 45 days, respectively. The pharmacokinetics of ranitidine derived from ranitidine bismuth citrate were similar to those of ranitidine administered alone. Ranitidine did not appreciably accumulate in plasma. Ranitidine bismuth citrate was well-tolerated during 28 days of repeated dosing. PMID:8864319

  3. Interactive effects of redox intensity and phosphate availability on growth and nutrient relations of Cladium jamaicense (Cyperaceae)

    USGS Publications Warehouse

    Lissner, J.; Mendelssohn, I.A.; Lorenzen, B.; Brix, H.; McKee, K.L.; Miao, S.L.

    2003-01-01

    Expansion of Typha domingensis into areas previously dominated by Cladium jamaicense in the Florida Everglades has been linked to anthropogenic phosphorus (P) enrichment and increased hydroperiod. The principal stress factor for plants in flooded soils is biochemical reduction, the intensity of which is measured as redox potential (Eh). The objective of this study was to assess the growth response of C. jamaicense to Eh (-150, +150, and +600 mV) and P availability (10, 80, and 500 ??g P/L). Plants were grown hydroponically in a factorial experiment using titanium (Ti3+) citrate as an Eh buffer. Treatment effects on growth, biomass partitioning, and tissue nutrients were recorded. Growth approximately doubled in response to a 50-fold increase in P availability. Low redox significantly reduced growth and tissue P concentration. While plant P concentrations increased 20-fold between the 10 and 500 ??g P/L treatments, P concentrations were 50-100% higher at +600 mV than at -150 mV within each phosphate level. At high Eh, C. jamaicense appears well adapted to low nutrient environments because of its low P requirement and high retention of acquired E However, at low Eh the ability to acquire or conserve acquired P decreases and as a consequence, higher phosphate levels are required to sustain growth. Findings of this study indicate that young C. jamaicense exhibits low tolerance to strongly reducing conditions when phosphate is scarce.

  4. Citrate modulates lipopolysaccharide-induced monocyte inflammatory responses

    PubMed Central

    Ashbrook, M J; McDonough, K L; Pituch, J J; Christopherson, P L; Cornell, T T; Selewski, D T; Shanley, T P; Blatt, N B

    2015-01-01

    Citrate, a central component of cellular metabolism, is a widely used anti-coagulant due to its ability to chelate calcium. Adenosine triphosphate (ATP)-citrate lyase, which metabolizes citrate, has been shown to be essential for inflammation, but the ability of exogenous citrate to impact inflammatory signalling cascades remains largely unknown. We hypothesized that citrate would modulate inflammatory responses as both a cellular metabolite and calcium chelator, and tested this hypothesis by determining how clinically relevant levels of citrate modulate monocyte proinflammatory responses to lipopolysaccharide (LPS) in a human acute monocytic leukaemia cell line (THP-1). In normal medium (0·4 mM calcium), citrate inhibited LPS-induced tumour necrosis factor (TNF)-α and interleukin (IL)-8 transcripts, whereas in medium supplemented with calcium (1·4 mM), TNF-α and IL-8 levels increased and appeared independent of calcium chelation. Using an IL-8–luciferase plasmid construct, the same increased response was observed in the activation of the IL-8 promoter region, suggesting transcriptional regulation. Tricarballylic acid, an inhibitor of ATP-citrate lyase, blocked the ability of citrate to augment TNF-α, linking citrate's augmentation effect with its metabolism by ATP-citrate lyase. In the presence of citrate, increased histone acetylation was observed in the TNF-α and IL-8 promoter regions of THP-1 cells. We observed that citrate can both augment and inhibit proinflammatory cytokine production via modulation of inflammatory gene transactivation. These findings suggest that citrate anti-coagulation may alter immune function through complex interactions with the inflammatory response. PMID:25619261

  5. Anchored [RuCl2(p-cymene)]2 in hybrid zirconium phosphate-phosphonate coated and pillared with double-stranded hydrophobic linear polystyrene as heterogeneous catalyst suitable for aqueous asymmetric transfer hydrogenation.

    PubMed

    Wang, Rui; Wan, Jingwei; Ma, Xuebing; Xu, Xiao; Liu, Liu

    2013-05-14

    A novel type of phosphonate-containing polystyrene copolymers 1a-e bearing an N'-alkylated TsDPEN chiral ligand and double-stranded polystyrene chains were prepared for the first time using simple radical copolymerization of 1-phosphonate styrene with (R,R)-N'-4'-vinylbenzyl-N-4-vinylbenzenesulfonyl-1,2-diphenylethylene-1,2-diamine. Through the coprecipitation of their supported Ru polystyrene copolymers 2a-e and NaH2PO4 with ZrOCl2, pillared hybrid zirconium phosphate-phosphonate-anchored Ru catalysts 3a-e and 4d1-d5 were obtained as heterogeneous catalysts suitable for aqueous asymmetric transfer hydrogenation. In the aqueous asymmetric transfer hydrogenation of aromatic ketones, the anchored Ru catalysts showed good catalytic activities, chemoselectivities (~100%), and enantioselectivities (73.6% ee to 95.6% ee). The Ru catalysts retained their catalytic properties even at the fifth recycle time (92.2% conv., 92.1% ee). However, corresponding supported Ru catalyst 3d' resulted in disappointing reusability because of the loss of ruthenium in every recycle process. The conversions of aromatic ketones were closely related to the o-, m- or p-positions of the substituents on the aromatic ring caused by shape-selective matching.

  6. A Phase 1B, randomized, double blind, placebo controlled, multiple-dose escalation study of NSI-189 phosphate, a neurogenic compound, in depressed patients

    PubMed Central

    Fava, M; Johe, K; Ereshefsky, L; Gertsik, L G; English, B A; Bilello, J A; Thurmond, L M; Johnstone, J; Dickerson, B C; Makris, N; Hoeppner, B B; Flynn, M; Mischoulon, D; Kinrys, G; Freeman, M P

    2016-01-01

    We wanted to examine tolerability and efficacy of NSI-189, a benzylpiperizine-aminiopyridine neurogenic compound for treating major depressive disorder (MDD). This was a Phase 1B, double blind, randomized, placebo controlled, multiple-dose study with three cohorts. The first cohort received 40 mg q.d. (n=6) or placebo (n=2), the second cohort 40 mg b.i.d. (n=6) or placebo (n=2), and the third cohort 40 mg t.i.d. (n=6) or placebo (n=2). Twenty-four patients with MDD were recruited, with the diagnosis and severity confirmed through remote interviews. Eligible patients received NSI-189 or placebo for 28 days in an inpatient setting with assessments for safety, pharmacokinetics (PK) and efficacy. Outpatient follow-up visits were conducted until day 84 (±3). NSI-189 was relatively well tolerated at all doses, with no serious adverse effects. NSI-189 area under the curve increased in a dose-related and nearly proportional manner across the three cohorts, with a half-life of 17.4–20.5 h. The exploratory efficacy measurements, including Symptoms Of Depression Questionnaire (SDQ), Montgomery-Asberg Depression Scale (MADRS), Clinical Global Impressions—Improvement (CGI-I), and The Massachusetts General Hospital (MGH) Cognitive and Physical Functioning Questionnaire (CPFQ) showed a promising reduction in depressive and cognitive symptoms across all measures for NSI-189, with significant improvement in the SDQ and CPFQ, and a medium to large effect size for all measures. These improvements persisted during the follow-up phase. In summary, NSI-189 shows potential as a treatment for MDD in an early phase study. The main limitation of this preliminary study was the small sample size of each cohort. PMID:26643541

  7. Assembly of citrate gold nanoparticles on hydrophilic monolayers

    NASA Astrophysics Data System (ADS)

    Vikholm-Lundin, Inger; Rosqvist, Emil; Ihalainen, Petri; Munter, Tony; Honkimaa, Anni; Marjomäki, Varpu; Albers, Willem M.; Peltonen, Jouko

    2016-08-01

    Self-assembled monolayers (SAMs) as model surfaces were linked onto planar gold films thorough lipoic acid or disulfide groups. The molecules used were polyethylene glycol (EG-S-S), N-[tris-(hydroxymethyl)methyl]acrylamide polymers with and without lipoic acid (Lipa-pTHMMAA and pTHMMAA) and a lipoic acid triazine derivative (Lipa-MF). All the layers, but Lipa-MF with a primary amino group were hydroxyl terminated. The layers were characterized by contact angle measurements and atomic force microscopy, AFM. Citrate stabilized nanoparticles, AuNPs in water and phosphate buffer were allowed to assemble on the layers for 10 min and the binding was followed in real-time with surface plasmon resonance, SPR. The SPR resonance curves were observed to shift to higher angles and become increasingly damped, while also the peaks strongly broaden when large nanoparticles assembled on the surface. Both the angular shift and the damping of the curve was largest for nanoparticles assembling on the EG-S-S monolayer. High amounts of particles were also assembled on the pTHMMAA layer without the lipoic acid group, but the damping of the curve was considerably lower with a more even distribution of the particles. Topographical images confirmed that the highest number of particles were assembled on the polyethylene glycol monolayer. By increasing the interaction time more particles could be assembled on the surface.

  8. Reduction of costs for anemia-management drugs associated with the use of ferric citrate

    PubMed Central

    Thomas, Anila; Peterson, Leif E

    2014-01-01

    Background Ferric citrate is a novel phosphate binder which has the potential to reduce usage of erythropoietin-stimulating agents (ESAs) and intravenous (IV) iron used for anemia management during hemodialysis (HD) among patients with end-stage renal disease (ESRD). Currently, the potential health care cost savings on a national scale due to the use of ferric citrate in ESRD are undetermined. Methods Per-patient-per-year costs of ESAs (Epogen® and Aranesp® [Amgen Inc., CA, USA]) and IV iron (Venofer® [American Regent, Inc., NY, USA] and Ferrlecit® [Sanofi US, Bridgewater, NJ, USA]) were based on RED BOOK™ (Truven Health Analytics New York, NY, USA) costs combined with the Centers for Medicare and Medicaid Services (CMS) base rate and actual usage in 2011 for the four drugs. The annual number of outpatients undergoing HD in the US was based on frequencies reported by the USRDS (United States Renal Data System). Monte Carlo uncertainty analysis was performed to determine total annual costs and cost reduction based on ferric citrate usage. Results Total annual cost of ESAs and IV iron for anemia management in ESRD determined by Monte Carlo analysis assuming CMS base rate value was 5.127 (3.664–6.260) billion USD. For actual utilization in 2011, total annual cost of ESAs and IV iron was 3.981 (2.780–4.930) billion USD. If ferric citrate usage reduced ESA utilization by 20% and IV iron by 40%, then total cost would be reduced by 21.2% to 4.038 (2.868–4.914) billion USD for the CMS base rate, and by 21.8% to 3.111 (2.148–3.845) billion USD, based on 2011 actual utilization. Conclusion It is likely that US health care costs for anemia-management drugs associated with ESRD among HD patients can be reduced by using ferric citrate as a phosphate binder. PMID:24899820

  9. Nanoscale observations of the effect of citrate on calcium oxalate precipitation on calcite surfaces.

    NASA Astrophysics Data System (ADS)

    Burgos-Cara, Alejandro; Ruiz-Agudo, Encarnacion; Putnis, Christine V.

    2016-04-01

    Calcium oxalate (CaC2O4ṡxH2O) minerals are naturally occurring minerals found in fossils, plants, kidney stones and is a by-product in some processes such as paper, food and beverage production [1,2]. In particular, calcium oxalate monohydrate phase (COM) also known as whewellite (CaC2O4ṡH2O), is the most frequently reported mineral phase found in urinary and kidney stones together with phosphates. Organic additives are well known to play a key role in the formation of minerals in both biotic and abiotic systems, either facilitating their precipitation or hindering it. In this regard, recent studies have provided direct evidence demonstrating that citrate species could enhance dissolution of COM and inhibit their precipitation. [3,4] The present work aims at evauate the influence of pH, citrate and oxalic acid concentrations in calcium oxalate precipitation on calcite surfaces (Island Spar, Chihuahua, Mexico) through in-situ nanoscale observation using in situ atomic force microscopy (AFM, Multimode, Bruker) in flow-through experiments. Changes in calcium oxalate morphologies and precipitated phases were observed, as well as the inhibitory effect of citrate on calcium oxalate precipitation, which also lead to stabilization an the amorphous calcium oxalate phase. [1] K.D. Demadis, M. Öner, Inhibitory effects of "green"additives on the crystal growth of sparingly soluble salts, in: J.T. Pearlman (Ed.), Green Chemistry Research Trends, Nova Science Publishers Inc., New York, 2009, pp. 265-287. [2] M. Masár, M. Zuborová, D. Kaniansky, B. Stanislawski, Determination of oxalate in beer by zone electrophoresis on a chip with conductivity detection, J. Sep. Sci. 26 (2003) 647-652. [3] Chutipongtanate S, Chaiyarit S, Thongboonkerd V. Citrate, not phosphate, can dissolve calcium oxalate monohydrate crystals and detach these crystals from renal tubular cells. Eur J Pharmacol 2012;689:219-25. [4] Weaver ML, Qiu SR, Hoyer JR, Casey WH, Nancollas GH, De Yoreo JJ

  10. Probing intermolecular interactions in a diethylcarbamazine citrate salt by fast MAS (1)H solid-state NMR spectroscopy and GIPAW calculations.

    PubMed

    Venâncio, Tiago; Oliveira, Lyege Magalhaes; Ellena, Javier; Boechat, Nubia; Brown, Steven P

    2017-03-02

    Fast magic-angle spinning (MAS) NMR is used to probe intermolecular interactions in a diethylcarbamazine salt, that is widely used as a treatment against adult worms of Wuchereria bancrofti which cause a common disease in tropical countries named filariasis. Specifically, a dihydrogen citrate salt that has improved thermal stability and solubility as compared to the free form is studied. One-dimensional (1)H, (13)C and (15)N and two-dimensional (1)H-(13)C and (14)N-(1)H heteronuclear correlation NMR experiments under moderate and fast MAS together with GIPAW (CASTEP) calculations enable the assignment of the (1)H, (13)C and (14)N/(15)N resonances. A two-dimensional (1)H-(1)H double-quantum (DQ) -single-quantum (SQ) MAS spectrum recorded with BaBa recoupling at 60kHz MAS identifies specific proton-proton proximities associated with citrate-citrate and citrate-diethylcarbamazine intermolecular interactions.

  11. Additive concentration effects on dicalcium phosphate dihydrate cements prepared using monocalcium phosphate monohydrate and hydroxyapatite.

    PubMed

    Santa Cruz Chavez, Grace; Alge, Daniel L; Chu, Tien-Min Gabriel

    2011-12-01

    In our previous study, we investigated the setting time, mechanical properties and microstructure of dicalcium phosphate dihydrate cements prepared using monocalcium phosphate monohydrate (MCPM) and hydroxyapatite (HA). Despite the use of sodium citrate as a setting regulator, setting occurs rapidly in the MCPM/HA system and further studies on other retardants are needed. In the present study, sodium pyrophosphate and sulfuric acid were tested to evaluate their effectiveness in maintaining workability of the cement paste. MCPM/HA cements at a powder to liquid ratio of 1.0 with sodium pyrophosphate and sulfuric acid at 10, 25, 50, 75 and 100 mM were manufactured and studied based on their setting time, mechanical and porosity properties, phase composition, and microstructure. These measurements were compared to our previous data using sodium citrate. The results showed that the additives have a dose-dependent effect on the setting time. Their order of efficiency is sodium pyrophosphate > sodium citrate > sulfuric acid. However, the sulfuric acid group exhibited the highest compressive strength (CS) compared to the other groups. A lack of correlation between the CS and the porosity of the cements suggested that a mechanism other than porosity reduction was responsible for the CS increase. Since x-ray diffraction analysis did not indicate an effect on composition, explanations based on calcium sulfate dihydrate formation and changes in microstructure were proposed based on scanning electron micrograph observations.

  12. Monte Carlo Simulations of Phosphate Polyhedron Connectivity in Glasses

    SciTech Connect

    ALAM,TODD M.

    1999-12-21

    Monte Carlo simulations of phosphate tetrahedron connectivity distributions in alkali and alkaline earth phosphate glasses are reported. By utilizing a discrete bond model, the distribution of next-nearest neighbor connectivities between phosphate polyhedron for random, alternating and clustering bonding scenarios was evaluated as a function of the relative bond energy difference. The simulated distributions are compared to experimentally observed connectivities reported for solid-state two-dimensional exchange and double-quantum NMR experiments of phosphate glasses. These Monte Carlo simulations demonstrate that the polyhedron connectivity is best described by a random distribution in lithium phosphate and calcium phosphate glasses.

  13. Effect of prolonged exercise on muscle citrate concentration before and after endurance training in men.

    PubMed

    Coggan, A R; Spina, R J; Kohrt, W M; Holloszy, J O

    1993-02-01

    It has been hypothesized that endurance training reduces carbohydrate utilization during exercise via citrate-mediated inhibition of phosphofructokinase (PFK). To test this hypothesis, vastus lateralis muscle biopsy samples were obtained from eight men before and immediately (approximately 10 s) after 2 h of cycle ergometer exercise at 60% of pretraining peak O2 uptake, both before and after 12 wk of endurance exercise training (3 days/wk running, 3 days/wk interval cycling). Training increased muscle citrate synthase (CS) activity from 3.69 +/- 0.48 (SE) to 5.30 +/- 0.42 mol.h-1.kg protein-1 and decreased the mean respiratory exchange ratio during exercise from 0.92 +/- 0.01 to 0.88 +/- 0.01 (both P < 0.001). Muscle citrate concentration at the end of exercise correlated significantly with CS activity (r = 0.70; P < 0.005) and was slightly but not significantly higher after training (0.80 +/- 0.19 vs. 0.54 +/- 0.19 mmol/kg dry wt; P = 0.16). Muscle glucose 6-phosphate (G-6-P) concentration at the end of exercise, however, was 31% lower in the trained state (1.17 +/- 0.10 vs. 1.66 +/- 0.27 mmol/kg dry wt; P < 0.05), in keeping with a 36% decrease in the amount of muscle glycogen utilized (133 +/- 22 vs. 209 +/- 19 mmol.kg dry wt-1.2 h-1; P < 0.01). The lower G-6-P concentration after training suggests that the training-induced reduction in carbohydrate utilization results from attenuation of flux before the PFK step in glycolysis and is not due to citrate-mediated inhibition of PFK.

  14. Sildenafil citrate for female sexual arousal disorder: a future possibility?

    PubMed

    Schoen, Corina; Bachmann, Gloria

    2009-04-01

    Female sexual arousal disorder (FSAD) is a common disorder encountered in clinical practice, with self-reported arousal difficulties reported in up to 26% of American women. Various oral therapies for FSAD have been studied, including sildenafil citrate, a phosphodiesterase inhibitor that is currently used to treat male erectile dysfunction. In vitro studies of sildenafil citrate have demonstrated smooth-muscle relaxation in clitoral tissue, and phosphodiesterase type-5 has been shown to be present in vaginal, clitoral and labial smooth muscle; these findings have led to theories that sildenafil citrate might be successful for treating FSAD. This Review discusses the data from clinical trials that have assessed sildenafil citrate for the treatment of FSAD; the trials show that sildenafil citrate is moderately effective. Sildenafil citrate may also be effective in women with FSAD secondary to multiple sclerosis, diabetes or antidepressant use; however, more trials in these patient populations are required to confirm these findings.

  15. Citrate in plasma and urine during total fasting.

    PubMed

    Nielsen, T T; Sørensen, N S

    1979-01-01

    Plasma citrate was determined in 12 obese subjects who underwent total fasting for 10 days. Mean plasma citrate concentration rose significantly from 128 before to 205 micro mol/1 on the 10th day of fasting. Plasma citrate rose continuously during fasting in seven subjects in whom daily determinations were carried out. The 24-hour urinary citrate excretion was followed in six subjects. A significant decrease was found from 2.91 mmol/24 h in the prefasting state to 0.25 mmol/24 h at the end of the fast. Intravenous glucose tolerance test were performed before and on the 10th day of fasting. Kivgtt decreased significantly and was inversely related to plasma citrate concentration on the 10th day of fasting. The results agree well with the concept that an increased citrate level of tissues is of regulatory importance for the decreased glucose utilization during fasting in man.

  16. SbnG, a Citrate Synthase in Staphylococcus aureus

    PubMed Central

    Kobylarz, Marek J.; Grigg, Jason C.; Sheldon, Jessica R.; Heinrichs, David E.; Murphy, Michael E. P.

    2014-01-01

    In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production. PMID:25336653

  17. 77 FR 24461 - Citric Acid and Certain Citrate Salts From Canada: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-24

    ... all grades and granulation sizes of citric acid, sodium citrate, and potassium citrate in their... blends of citric acid, sodium citrate, and potassium citrate; as well as blends with other ingredients, such as sugar, where the unblended form(s) of citric acid, sodium citrate, and potassium...

  18. The distribution of plasmids determining citrate utilization in citrate-positive variants of Escherichia coli from humans, domestic animals, feral birds and environments.

    PubMed

    Ishiguro, N; Sato, G

    1979-10-01

    Sixty-seven isolates of citrate-positive variants of Escherichia coli were isolated from human, domestic animal, feral bird and environmental sources. With the exception of citrate utilization, all isolates were identified as typical E. coli by their biochemical reactions. The transmission of the ability to utilize citrate on Simmons' citrate agar was demonstrated in 53 (79.1%) out of the 67 citrate-positive E. coli variants obtained from various sources. Drug resistance determinants and citrate utilizing character were co-transmitted into E. coli K-12 by conjugation among citrate-positive E. coli isolates carrying R plasmids except for that isolated from horses. The other characters (haemolysin or colicin production, raffinose or sucrose fermentation) were not transmitted together with the citrate utilizing character. These facts suggested that the structural gene responsible for citrate utilizing ability in citrate-positive variants of E. coli was located on a conjugative plasmid.

  19. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  20. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  1. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  2. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  3. 21 CFR 73.1025 - Ferric ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Ferric ammonium citrate. 73.1025 Section 73.1025 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1025 Ferric ammonium citrate. (a) Identity....

  4. Characterization of ATP citrate lyase from Chlorobium limicola.

    PubMed Central

    Antranikian, G; Herzberg, C; Gottschalk, G

    1982-01-01

    ATP citrate lyase (EC 4.1.3.8) from Chlorobium limicola was partially purified. It was established that the consumption of substrates and the formation of products proceeded stoichiometrically and that citrate cleavage was of the si-type. ADP and oxaloacetate inhibited enzyme activity. Oxaloacetate also inhibited the growth of C. limicola. PMID:7142107

  5. 21 CFR 184.1140 - Ammonium citrate, dibasic.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Listing of Specific Substances Affirmed as GRAS § 184.1140 Ammonium citrate, dibasic. (a) Ammonium citrate, dibasic ((NH4)2HC6H5O7, CAS Reg. No. 3012-65-5) is the diammonium salt of citric acid. It is prepared by partially neutralizing citric acid with ammonia. (b) The ingredient must be of a purity suitable for...

  6. 21 CFR 184.1140 - Ammonium citrate, dibasic.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Listing of Specific Substances Affirmed as GRAS § 184.1140 Ammonium citrate, dibasic. (a) Ammonium citrate, dibasic ((NH4)2HC6H5O7, CAS Reg. No. 3012-65-5) is the diammonium salt of citric acid. It is prepared by partially neutralizing citric acid with ammonia. (b) The ingredient must be of a purity suitable for...

  7. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Iron-choline citrate complex. 172.370 Section 172... CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline... citric acid may be safely used as a source of iron in foods for special dietary use....

  8. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Iron-choline citrate complex. 172.370 Section 172... CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline... citric acid may be safely used as a source of iron in foods for special dietary use....

  9. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Iron-choline citrate complex. 172.370 Section 172... CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline... citric acid may be safely used as a source of iron in foods for special dietary use....

  10. Enhanced dissolution of sildenafil citrate as dry foam tablets.

    PubMed

    Sawatdee, Somchai; Atipairin, Apichart; Sae Yoon, Attawadee; Srichana, Teerapol; Changsan, Narumon

    2017-01-30

    Dry foam formulation technology is alternative approach to enhance dissolution of the drug. Sildenafil citrate was suspended in sodium dodecyl sulfate solution and adding a mixture of maltodextrin and mannitol as diluent to form a paste. Sildenafil citrate paste was passed through a nozzle spray bottle to obtain smooth foam. The homogeneous foam was dried in a vacuum oven and sieved to obtain dry foam granules. The granules were mixed with croscarmellose sodium, magnesium stearate and compressed into tablet. All formulations were evaluated for their physicochemical properties and dissolution profiles. All the tested excipients were compatible with sildenafil citrate by both differential scanning calorimetry (DSC) and infrared (IR) analysis. There are no X-ray diffraction (XRD) peaks representing crystals of sildenafil citrate observed form dry foam formulations. The hardness of tablets was about 5 kg, friability test <1% with a disintegration time <5 min. The sildenafil citrate dry foam tablet had higher dissolution rate in 0.1 N HCl in comparison with commercial sildenafil citrate tablet, sildenafil citrate prepared by direct compression and wet granulation method. Sildenafil citrate dry foam tablet with the high-level composition of surfactant, water and diluent showed enhanced dissolution rate than that of the lower-level composition of these excipients. This formulation was stable under accelerated conditions for at least 6 months.

  11. 21 CFR 172.370 - Iron-choline citrate complex.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron-choline citrate complex. 172.370 Section 172... CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline... citric acid may be safely used as a source of iron in foods for special dietary use....

  12. Diffuse abdominal gallium-67 citrate uptake in salmonella infections

    SciTech Connect

    Garty, I.; Koren, A.

    1987-11-01

    Two pediatric patients with salmonella infections (one with typhoid fever and the second with salmonella C2 gastroenteritis), had a diffuse abdominal uptake of Ga-67 citrate. The possible explanation for this finding is discussed. Salmonella infection should be included as a cause in the differential diagnosis of diffuse accumulation of Ga-67 citrate.

  13. Structural basis for norovirus inhibition and fucose mimicry by citrate.

    PubMed

    Hansman, Grant S; Shahzad-Ul-Hussan, Syed; McLellan, Jason S; Chuang, Gwo-Yu; Georgiev, Ivelin; Shimoike, Takashi; Katayama, Kazuhiko; Bewley, Carole A; Kwong, Peter D

    2012-01-01

    Human noroviruses bind with their capsid-protruding domains to histo-blood-group antigens (HBGAs), an interaction thought to direct their entry into cells. Although human noroviruses are the major cause of gastroenteritis outbreaks, development of antivirals has been lacking, mainly because human noroviruses cannot be cultivated. Here we use X-ray crystallography and saturation transfer difference nuclear magnetic resonance (STD NMR) to analyze the interaction of citrate with genogroup II (GII) noroviruses. Crystals of citrate in complex with the protruding domain from norovirus GII.10 Vietnam026 diffracted to 1.4 Å and showed a single citrate bound at the site of HBGA interaction. The citrate interaction was coordinated with a set of capsid interactions almost identical to that involved in recognizing the terminal HBGA fucose, the saccharide which forms the primary conserved interaction between HBGAs and GII noroviruses. Citrate and a water molecule formed a ring-like structure that mimicked the pyranoside ring of fucose. STD NMR showed the protruding domain to have weak affinity for citrate (460 μM). This affinity, however, was similar to the affinities of the protruding domain for fucose (460 μM) and H type 2 trisaccharide (390 μM), an HBGA shown previously to be specifically recognized by human noroviruses. Importantly, competition STD NMR showed that citrate could compete with HBGA for norovirus binding. Together, the results suggest that citrate and other glycomimetics have the potential to block human noroviruses from binding to HBGAs.

  14. Structural Basis for Norovirus Inhibition and Fucose Mimicry by Citrate

    SciTech Connect

    Hansman, Grant S.; Shahzad-ul-Hussan, Syed; McLellan, Jason S.; Chuang, Gwo-Yu; Georgiev, Ivelin; Shimoike, Takashi; Katayama, Kazuhiko; Bewley, Carole A.; Kwong, Peter D.

    2012-01-20

    Human noroviruses bind with their capsid-protruding domains to histo-blood-group antigens (HBGAs), an interaction thought to direct their entry into cells. Although human noroviruses are the major cause of gastroenteritis outbreaks, development of antivirals has been lacking, mainly because human noroviruses cannot be cultivated. Here we use X-ray crystallography and saturation transfer difference nuclear magnetic resonance (STD NMR) to analyze the interaction of citrate with genogroup II (GII) noroviruses. Crystals of citrate in complex with the protruding domain from norovirus GII.10 Vietnam026 diffracted to 1.4 {angstrom} and showed a single citrate bound at the site of HBGA interaction. The citrate interaction was coordinated with a set of capsid interactions almost identical to that involved in recognizing the terminal HBGA fucose, the saccharide which forms the primary conserved interaction between HBGAs and GII noroviruses. Citrate and a water molecule formed a ring-like structure that mimicked the pyranoside ring of fucose. STD NMR showed the protruding domain to have weak affinity for citrate (460 {mu}M). This affinity, however, was similar to the affinities of the protruding domain for fucose (460 {mu}M) and H type 2 trisaccharide (390 {mu}M), an HBGA shown previously to be specifically recognized by human noroviruses. Importantly, competition STD NMR showed that citrate could compete with HBGA for norovirus binding. Together, the results suggest that citrate and other glycomimetics have the potential to block human noroviruses from binding to HBGAs.

  15. 21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Diethylcarbamazine citrate oral dosage forms....

  16. 21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Diethylcarbamazine citrate oral dosage forms....

  17. 21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Diethylcarbamazine citrate oral dosage forms....

  18. 21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... Diethylcarbamazine citrate oral dosage forms....

  19. Injectable citrate-modified Portland cement for use in vertebroplasty.

    PubMed

    Wynn-Jones, Gareth; Shelton, Richard M; Hofmann, Michael P

    2014-11-01

    The injectability of Portland cement (PC) with several citrate additives was investigated for use in clinical applications such as vertebroplasty (stabilization of a fractured vertebra with bone cement) using a syringe. A 2-wt % addition of sodium or potassium citrate with PC significantly improved cement injectability, decreased cement setting times from over 2 h to below 25 min, while increasing the compressive strength to a maximum of 125 MPa. Zeta-potential measurements indicated that the citrate anion was binding to one or more of the positively charged species causing charged repulsion between cement particles which dispersed aggregates and caused the liquefying effect of the anion. Analysis of the hydrating phases of PC indicated that the early strength producing PC phase (ettringite) developed within the first 2 h of setting following addition of the citrate anion, while this did not occur in the control cement (PC only). Within 24 h ettringite developed in PC as well as calcium-silicate-hydrate (C-S-H), the major setting phase of PC, whereas cements containing citrate did not develop this phase. The evidence suggested that in the presence of citrate the cements limited water supply appeared to be utilized for ettringite formation, producing the early strength of the citrate cements. The present study has demonstrated that it is possible to modify PC with citrate to both improve the injectability and crucially reduce the setting times of PC while improving the strength of the cement.

  20. Citrate synthesis in intact rat-liver mitochondria is irreversible.

    PubMed

    Greksák, M; Lopes-Cardozo, M; van den Bergh, S G

    1982-02-01

    Rat-liver mitochondria were incubated with [1,5-14C]citrate in the presence of fluorocitrate to block its oxidation in the Krebs cycle. The reaction products were analysed enzymatically and by anion-exchange chromatography. Incorporation of 14C into acetyl-L-carnitine or ketone bodies via a backward action of citrate synthase was not observed. The optimal rate of citrate synthesis from pyruvate and malate in the presence of fluorocitrate was 15 nmol . mg-1 min-1. In the absence of fluorocitrate, but in the presence of malonate, citrate was oxidized to succinate at a rate of 4 nmol . mg-1 . min-1. We conclude that the synthesis of citrate by intact rat liver mitochondria is an irreversible process. The possible mechanism underlying this phenomenon and the consequence for metabolic regulation are discussed.

  1. Synthesis and characterization of biomimetic citrate-based biodegradable composites.

    PubMed

    Tran, Richard T; Wang, Liang; Zhang, Chang; Huang, Minjun; Tang, Wanjin; Zhang, Chi; Zhang, Zhongmin; Jin, Dadi; Banik, Brittany; Brown, Justin L; Xie, Zhiwei; Bai, Xiaochun; Yang, Jian

    2014-08-01

    Natural bone apatite crystals, which mediate the development and regulate the load-bearing function of bone, have recently been associated with strongly bound citrate molecules. However, such understanding has not been translated into bone biomaterial design and osteoblast cell culture. In this work, we have developed a new class of biodegradable, mechanically strong, and biocompatible citrate-based polymer blends (CBPBs), which offer enhanced hydroxyapatite binding to produce more biomimetic composites (CBPBHAs) for orthopedic applications. CBPBHAs consist of the newly developed osteoconductive citrate-presenting biodegradable polymers, crosslinked urethane-doped polyester and poly (octanediol citrate), which can be composited with up to 65 wt % hydroxyapatite. CBPBHA networks produced materials with a compressive strength of 116.23 ± 5.37 MPa comparable to human cortical bone (100-230 MPa), and increased C2C12 osterix gene and alkaline phosphatase gene expression in vitro. The promising results above prompted an investigation on the role of citrate supplementation in culture medium for osteoblast culture, which showed that exogenous citrate supplemented into media accelerated the in vitro phenotype progression of MG-63 osteoblasts. After 6 weeks of implantation in a rabbit lateral femoral condyle defect model, CBPBHA composites elicited minimal fibrous tissue encapsulation and were well integrated with the surrounding bone tissues. The development of citrate-presenting CBPBHA biomaterials and preliminary studies revealing the effects of free exogenous citrate on osteoblast culture shows the potential of citrate biomaterials to bridge the gap in orthopedic biomaterial design and osteoblast cell culture in that the role of citrate molecules has previously been overlooked.

  2. Bioavailability of iron from ferric choline citrate and a ferric copper cobalt choline citrate complex for young pigs.

    PubMed

    Miller, E R; Parsons, M J; Ullrey, D E; Ku, P K

    1981-04-01

    Two experiments were conducted to determine the bioavailability for young pigs of Fe from ferric choline citrate or from a commercial mixture of Fe, Cu and Co choline citrate salts. Relative biological value of Fe from either source with a standard of 100 for FeSO4 x 7H20 was about 140 by both hemoglobin regeneration and Fe retention methods.

  3. Acquired immunodeficiency syndrome: Ga-67 citrate imaging

    SciTech Connect

    Woolfenden, J.M.; Carrasquillo, J.A.; Larson, S.M.; Simmons, J.T.; Masur, H.; Smith, P.D.; Shelhamer, J.H.; Ognibene, F.P.

    1987-02-01

    All gallium-67 citrate scans obtained in patients with acquired immunodeficiency syndrome (AIDS) at the Clinical Center, National Institutes of Health (Bethesda, Md.) were retrospectively analyzed and correlated with the results of bronchoscopy, chest radiography, and endoscopy. There were 164 scans of 95 patients. Twenty scans were from patients with Pneumocystis carinii pneumonia; 19 were abnormal, for a sensitivity of 95%. Ga-67 uptake tended to be less in patients receiving therapy for P. carinii pneumonia. Chest radiographs were normal at least initially in three patients with abnormal scans and P. carinii pneumonia. Unusually prominent colonic activity was associated with infection in some patients. No lesions of Kaposi sarcoma showed tracer uptake. Gallium scanning is useful for detecting P. carinii pneumonia and other opportunistic infections in patients with AIDS, but it is not useful for localizing Kaposi sarcoma.

  4. pH-responsive delivery of doxorubicin from citrate-apatite nanocrystals with tailored carbonate content.

    PubMed

    Rodríguez-Ruiz, Isaac; Delgado-López, José Manuel; Durán-Olivencia, Miguel A; Iafisco, Michele; Tampieri, Anna; Colangelo, Donato; Prat, Maria; Gómez-Morales, Jaime

    2013-07-02

    In this work, the efficiency of bioinspired citrate-functionalized nanocrystalline apatites as nanocarriers for delivery of doxorubicin (DOXO) has been assessed. The nanoparticles were synthesized by thermal decomplexing of metastable calcium/citrate/phosphate solutions both in the absence (Ap) and in the presence (cAp) of carbonate ions. The presence of citrate and carbonate ions in the solution allowed us to tailor the size, shape, carbonate content, and surface chemistry of the nanoparticles. The drug-loading efficiency of the two types of apatite was evaluated by means of the adsorption isotherms, which were found to fit a Langmuir-Freundlich behavior. A model describing the interaction between apatite surface and DOXO is proposed from adsorption isotherms and ζ-potential measurements. DOXO is adsorbed as a dimer by means of a positively charged amino group that electrostatically interacts with negatively charged surface groups of nanoparticles. The drug-release profiles were explored at pHs 7.4 and 5.0, mimicking the physiological pH in the blood circulation and the more acidic pH in the endosome-lysosome intracellular compartment, respectively. After 7 days at pH 7.4, cAp-DOXO released around 42% less drug than Ap-DOXO. However, at acidic pH, both nanoassemblies released similar amounts of DOXO. In vitro assays analyzed by confocal microscopy showed that both drug-loaded apatites were internalized within GTL-16 human carcinoma cells and could release DOXO, which accumulated in the nucleus in short times and exerted cytotoxic activity with the same efficiency. cAp are thus expected to be a more promising nanocarrier for experiments in vivo, in situations where intravenous injection of nanoparticles are required to reach the targeted tumor, after circulating in the bloodstream.

  5. Hanford 100-N Area In Situ Apatite and Phosphate Emplacement by Groundwater and Jet Injection: Geochemical and Physical Core Analysis

    SciTech Connect

    Szecsody, James E.; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.; Rockhold, Mark L.; Qafoku, Nikolla; Phillips, Jerry L.

    2010-07-01

    The purpose of this study is to evaluate emplacement of phosphate into subsurface sediments in the Hanford Site 100-N Area by two different technologies: groundwater injection of a Ca-citrate-PO4 solution and water-jet injection of sodium phosphate and/or fish-bone apatite. In situ emplacement of phosphate and apatite adsorbs, then incorporates Sr-90 into the apatite structure by substitution for calcium. Overall, both technologies (groundwater injection of Ca-citrate-PO4) and water-jet injection of sodium phosphate/fish-bone apatite) delivered sufficient phosphate to subsur¬face sediments in the 100-N Area. Over years to decades, additional Sr-90 will incorporate into the apatite precipitate. Therefore, high pressure water jetting is a viable technology to emplace phosphate or apatite in shallow subsurface sediments difficult to emplace by Ca-citrate-PO4 groundwater injections, but further analysis is needed to quantify the relevant areal extent of phosphate deposition (in the 5- to 15-ft distance from injection points) and cause of the high deposition in finer grained sediments.

  6. Phosphate Removal by Anion Binding on Functionalized Nanoporous Sorbents

    PubMed Central

    Chouyyok, Wilaiwan; Wiacek, Robert J.; Pattamakomsan, Kanda; Sangvanich, Thanapon; Grudzien, Rafal M.; Fryxell, Glen E.; Yantasee, Wassana

    2010-01-01

    Phosphate was captured from aqueous solutions by cationic metal-EDA complexes anchored inside mesoporous silica MCM-41 supports (Cu(II)-EDA-SAMMS and Fe(III)-EDA-SAMMS). Fe-EDA-SAMMS was more effective at capturing phosphate than the Cu-EDA-SAMMS and was further studied for matrix effects (e.g., pH, ionic strength, and competing anions) and sorption performance (e.g., capacity and rate). The adsorption of phosphate was highly pH dependent; it increased with increasing pH from 1.0 to 6.5, and decreased above pH 6.5. The adsorption was affected by high ionic strength (0.1 M of NaCl). In the presence of 1000-fold molar excess of chloride and nitrate anions, phosphate removal by Fe-EDA-SAMMS was not affected. Slight, moderate and large impacts were seen with bicarbonate, sulfate and citrate anions, respectively. The phosphate adsorption data on Fe-EDA-SAMMS agreed well with the Langmuir model with the estimated maximum capacity of 43.3 mg/g. The material displayed rapid sorption rate (99% of phosphate removal within 1 min) and lowering the phosphate content to ~ 10 µg/L of phosphorus, which is lower than the EPA’s established freshwater contaminant level for phosphorous (20 µg/L). PMID:20345133

  7. Acute effects of calcium carbonate, calcium citrate and potassium citrate on markers of calcium and bone metabolism in young women.

    PubMed

    Karp, Heini J; Ketola, Maarit E; Lamberg-Allardt, Christel J E

    2009-11-01

    Both K and Ca supplementation may have beneficial effects on bone through separate mechanisms. K in the form of citrate or bicarbonate affects bone by neutralising the acid load caused by a high protein intake or a low intake of alkalising foods, i.e. fruits and vegetables. Ca is known to decrease serum parathyroid hormone (S-PTH) concentration and bone resorption. We compared the effects of calcium carbonate, calcium citrate and potassium citrate on markers of Ca and bone metabolism in young women. Twelve healthy women aged 22-30 years were randomised into four controlled 24 h study sessions, each subject serving as her own control. At the beginning of each session, subjects received a single dose of calcium carbonate, calcium citrate, potassium citrate or a placebo in randomised order. The diet during each session was identical, containing 300 mg Ca. Both the calcium carbonate and calcium citrate supplement contained 1000 mg Ca; the potassium citrate supplement contained 2250 mg K. Markers of Ca and bone metabolism were followed. Potassium citrate decreased the bone resorption marker (N-terminal telopeptide of type I collagen) and increased Ca retention relative to the control session. Both Ca supplements decreased S-PTH concentration. Ca supplements also decreased bone resorption relative to the control session, but this was significant only for calcium carbonate. No differences in bone formation marker (bone-specific alkaline phosphatase) were seen among the study sessions. The results suggest that potassium citrate has a positive effect on the resorption marker despite low Ca intake. Both Ca supplements were absorbed well and decreased S-PTH efficiently.

  8. The role of nicotinamide–adenine dinucleotide phosphate-dependent malate dehydrogenase and isocitrate dehydrogenase in the supply of reduced nicotinamide–adenine dinucleotide phosphate for steroidogenesis in the superovulated rat ovary

    PubMed Central

    Flint, A. P. F.; Denton, R. M.

    1970-01-01

    1. Superovulated rat ovary was found to contain high activities of NADP–malate dehydrogenase and NADP–isocitrate dehydrogenase. The activity of each enzyme was approximately four times that of glucose 6-phosphate dehydrogenase and equalled or exceeded the activities reported to be present in other mammalian tissues. Fractionation of a whole tissue homogenate of superovulated rat ovary indicated that both enzymes were exclusively cytoplasmic. The tissue was also found to contain pyruvate carboxylase (exclusively mitochondrial), NAD–malate dehydrogenase and aspartate aminotransferase (both mitochondrial and cytoplasmic) and ATP–citrate lyase (exclusively cytoplasmic). 2. The kinetic properties of glucose 6-phosphate dehydrogenase, NADP–malate dehydrogenase and NADP–isocitrate dehydrogenase were determined and compared with the whole-tissue concentrations of their substrates and NADPH; NADPH is a competitive inhibitor of all three enzymes. The concentrations of glucose 6-phosphate, malate and isocitrate in incubated tissue slices were raised at least tenfold by the addition of glucose to the incubation medium, from the values below to values above the respective Km values of the dehydrogenases. Glucose doubled the tissue concentration of NADPH. 3. Steroidogenesis from acetate is stimulated by glucose in slices of superovulated rat ovary incubated in vitro. It was found that this stimulatory effect of glucose can be mimicked by malate, isocitrate, lactate and pyruvate. 4. It is concluded that NADP–malate dehydrogenase or NADP–isocitrate dehydrogenase or both may play an important role in the formation of NADPH in the superovulated rat ovary. It is suggested that the stimulatory effect of glucose on steroidogenesis from acetate results from an increased rate of NADPH formation through one or both dehydrogenases, brought about by the increases in the concentrations of malate, isocitrate or both. Possible pathways involving the two enzymes are discussed

  9. Properties of peroxisomal and mitochondrial citrate synthase from Agave americana.

    PubMed

    Segovia, J L; Zafra, M F; Alejandre, M J; García-Peregrín, E

    1982-09-01

    Adenine nucleotides were tested as effectors of peroxisomal and mitochondrial citrate synthase from Agave americana leaves in the presence of different concentrations of acetyl-CoA and oxalacetate substrates. ATP inhibited both enzyme activities but with a different inhibition profile. 1.0-7.5 mM ADP did not inhibit the peroxisomal citrate synthase in the presence of high substrate concentrations, while the mitochondrial enzyme was strongly inhibited by 1.0 mM ADP in the same conditions. Likewise, a different pattern was obtained with AMP on both peroxisomal and mitochondrial activities. The rate of citrate formation as function of acetyl-CoA and oxalacetate concentration was also studied in both fractions. Maximal velocity was highest in the peroxisomal fraction, whether acetyl-CoA or oxalacetate were the variable substrates. These differences indicate that peroxisomal and mitochondrial citrate synthases seem to be two different isoenzymes.

  10. Injectable citrate-modified Portland cement for use in vertebroplasty

    PubMed Central

    Wynn-Jones, Gareth; Shelton, Richard M; Hofmann, Michael P

    2014-01-01

    The injectability of Portland cement (PC) with several citrate additives was investigated for use in clinical applications such as vertebroplasty (stabilization of a fractured vertebra with bone cement) using a syringe. A 2-wt % addition of sodium or potassium citrate with PC significantly improved cement injectability, decreased cement setting times from over 2 h to below 25 min, while increasing the compressive strength to a maximum of 125 MPa. Zeta-potential measurements indicated that the citrate anion was binding to one or more of the positively charged species causing charged repulsion between cement particles which dispersed aggregates and caused the liquefying effect of the anion. Analysis of the hydrating phases of PC indicated that the early strength producing PC phase (ettringite) developed within the first 2 h of setting following addition of the citrate anion, while this did not occur in the control cement (PC only). Within 24 h ettringite developed in PC as well as calcium–silicate–hydrate (C–S–H), the major setting phase of PC, whereas cements containing citrate did not develop this phase. The evidence suggested that in the presence of citrate the cements limited water supply appeared to be utilized for ettringite formation, producing the early strength of the citrate cements. The present study has demonstrated that it is possible to modify PC with citrate to both improve the injectability and crucially reduce the setting times of PC while improving the strength of the cement. © 2014 The Authors Journal of Biomedical Materials Research Part B: Applied Biomaterials Published by Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 1799–1808, 2014. PMID:24711245

  11. Citrate-Based Biomaterials and Their Applications in Regenerative Engineering

    NASA Astrophysics Data System (ADS)

    Tran, Richard T.; Yang, Jian; Ameer, Guillermo A.

    2015-07-01

    Advances in biomaterials science and engineering are crucial to translating regenerative engineering, an emerging field that aims to recreate complex tissues, into clinical practice. In this regard, citrate-based biomaterials have become an important tool owing to their versatile material and biological characteristics including unique antioxidant, antimicrobial, adhesive, and fluorescent properties. This review discusses fundamental design considerations, strategies to incorporate unique functionality, and examples of how citrate-based biomaterials can be an enabling technology for regenerative engineering.

  12. Citrate-Based Biomaterials and Their Applications in Regenerative Engineering

    PubMed Central

    Tran, Richard T.; Yang, Jian; Ameer, Guillermo A.

    2015-01-01

    Advances in biomaterials science and engineering are crucial to translating regenerative engineering, an emerging field that aims to recreate complex tissues, into clinical practice. In this regard, citrate-based biomaterials have become an important tool owing to their versatile material and biological characteristics including unique antioxidant, antimicrobial, adhesive, and fluorescent properties. This review discusses fundamental design considerations, strategies to incorporate unique functionality, and examples of how citrate-based biomaterials can be an enabling technology for regenerative engineering. PMID:27004046

  13. Validated stability-indicating reversed-phase-HPLC method for simultaneous determination of orphenadrine citrate, caffeine and aspirin.

    PubMed

    Darwish, Khaled; Salama, Ismail; Mostafa, Samia; El-Sadek, Mohamed

    2012-01-01

    New, simple, rapid and precise reversed-phase high-performance liquid chromatographic method was developed for the simultaneous determination of orphenadrine citrate, caffeine and aspirin in presence of aspirin degradation products, orphenadrine citrate and caffeine process related impurities, and excipients. Good resolution and quantization were achieved on reversed-phase column [Phenomenex™ Luna ODS C(18) (25 cm×4.6 mm, 5 µm particles)]. Gradient elution based on; eluant [A]: 0.1% triethylamine in aqueous potassium dihydrogen phosphate buffer (50 mM; pH 3.0), while as, eluant [B]: acetonitrile, at a flow rate of 1.5 mL min(-1). UV quantitation was set at 215 nm. Linearity was exhibited for orphenadrine citrate, caffeine and aspirin within 0.5-150, 0.5-360 or 0.7-301 µg mL(-1) ranges, respectively. Satisfactory validation results were ascertained in terms of low limits of quantiation (6.33×10(-2)-7.94×10(-2)), mean percentage recovery (98.9-101.4%), precision (<2%) and robustness. The proposed method was proved to be specific, robust and accurate for the determination of cited drugs in pharmaceutical preparations in presence of their degradation products.

  14. Citrate uptake into Pectobacterium atrosepticum is critical for bacterial virulence.

    PubMed

    Urbany, Claude; Neuhaus, H Ekkehard

    2008-05-01

    To analyze whether metabolite import into Pectobacterium atrosepticum cells affects bacterial virulence, we investigated the function of a carrier which exhibits significant structural homology to characterized carboxylic-acid transport proteins. The corresponding gene, ECA3984, previously annotated as coding for a Na(+)/sulphate carrier, in fact encodes a highly specific citrate transporter (Cit1) which is energized by the proton-motive force. Expression of the cit1 gene is stimulated by the presence of citrate in the growth medium and is substantial during growth of P. atrosepticum on potato tuber tissue. Infection of tuber tissue with P. atrosepticum leads to reduced citrate levels. P. atrosepticum insertion mutants, lacking the functional Cit1 protein, did not grow in medium containing citrate as the sole carbon source, showed a substantially reduced ability to macerate potato tuber tissue, and did not provoke reduced citrate levels in the plant tissue upon infection. We propose that citrate uptake into P. atrosepticum is critical for full bacterial virulence.

  15. Synthesis and Antimicrobial Activity of Silver Citrate Complexes

    PubMed Central

    Djokić, Stojan

    2008-01-01

    Formation of silver citrate/citric acid complexed solutions was investigated. Although, silver citrate is minimally soluble in water, it can successfully be dissolved in citric acid solutions. The maximum concentration of Ag(I) in solution is estimated at 23 to 25 g/L if the concentration of citric acid is at least 4 mol/L or higher. The dissolution of silver citrate in citric acid solutions was attributed to the formation of silver citrate complexes of a general formula [Ag3(C6H5O7)n+1]3n−. The silver citrate/citric acid solutions, containing more than about 13 g/L Ag+ ion, have exhibited a decrease in Ag(I) concentration in solution over time, due to crystallization. The crystallization product was attributed to the formation of [Ag3C6H5O7]x·nH2O. Importantly, the diluted silver citrate/citric acid complexed solutions have exhibited very strong bacteriostatic and bactericidal activities. PMID:19079586

  16. Microbial solubilization of phosphate

    DOEpatents

    Rogers, Robert D.; Wolfram, James H.

    1993-01-01

    A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorous can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution.

  17. Microbial solubilization of phosphate

    DOEpatents

    Rogers, R.D.; Wolfram, J.H.

    1993-10-26

    A process is provided for solubilizing phosphate from phosphate containing ore by treatment with microorganisms which comprises forming an aqueous mixture of phosphate ore, microorganisms operable for solubilizing phosphate from the phosphate ore and maintaining the aqueous mixture for a period of time and under conditions operable to effect the microbial solubilization process. An aqueous solution containing soluble phosphorus can be separated from the reacted mixture by precipitation, solvent extraction, selective membrane, exchange resin or gravity methods to recover phosphate from the aqueous solution. 6 figures.

  18. Phosphate homeostasis and disorders.

    PubMed

    Manghat, P; Sodi, R; Swaminathan, R

    2014-11-01

    Recent studies of inherited disorders of phosphate metabolism have shed new light on the understanding of phosphate metabolism. Phosphate has important functions in the body and several mechanisms have evolved to regulate phosphate balance including vitamin D, parathyroid hormone and phosphatonins such as fibroblast growth factor-23 (FGF23). Disorders of phosphate homeostasis leading to hypo- and hyperphosphataemia are common and have clinical and biochemical consequences. Notably, recent studies have linked hyperphosphataemia with an increased risk of cardiovascular disease. This review outlines the recent advances in the understanding of phosphate homeostasis and describes the causes, investigation and management of hypo- and hyperphosphataemia.

  19. The periplasmic domain of the histidine autokinase CitA functions as a highly specific citrate receptor.

    PubMed

    Kaspar, S; Perozzo, R; Reinelt, S; Meyer, M; Pfister, K; Scapozza, L; Bott, M

    1999-08-01

    The two-component regulatory system CitA/CitB is essential for induction of the citrate fermentation genes in Klebsiella pneumoniae. CitA represents a membrane-bound sensor kinase consisting of a periplasmic domain flanked by two transmembrane helices, a linker domain and the conserved kinase or transmitter domain. A fusion protein (MalE-CitAC) composed of the maltose-binding protein and the CitA kinase domain (amino acids 327-547) showed constitutive autokinase activity and transferred the gamma-phosphate group of ATP to its cognate response regulator CitB. The autokinase activity of CitA was abolished by an H350L exchange, and phosphorylation of CitB was inhibited by a D56N exchange, indicating that H-350 and D-56 represent the phosphorylation sites of CitA and CitB respectively. In the presence of ATP, CitB-D56N formed a stable complex with MalE-CitAC. To analyse the sensory properties of CitA, the periplasmic domain (amino acids 45-176) was overproduced as a soluble, cytoplasmic protein with a C-terminally attached histidine tag (CitAPHis). Purified CitAPHis bound citrate, but none of the other tri- and dicarboxylates tested, with high affinity (KD approximately 5 microM at pH 7) in a 1:1 stoichiometry. As shown by isothermal titration calorimetry, the binding reaction was driven by the enthalpy change (DeltaH = -76.3 kJ mol-1), whereas the entropy change was opposed (-TDeltaS = + 46.3 kJ mol-1). The pH dependency of the binding reaction indicated that the dianionic form H-citrate2- is the citrate species recognized by CitAPHis. In the presence of Mg2+ ions, the dissociation constant increased significantly, suggesting that the Mg-citrate complex is not bound by CitAPHis. This work defines the periplasmic domain of CitA as a highly specific citrate receptor and elucidates the binding characteristics of CitAPHis.

  20. The sensor kinase CitA (DpiB) of Escherichia coli functions as a high-affinity citrate receptor.

    PubMed

    Kaspar, Sibylle; Bott, Michael

    2002-04-01

    For the CitA-CitB (DpiB-DpiA) two-component signal transduction system from Escherichia coli, three diverse functions have been reported: induction of the citrate fermentation genes citCDEFXGT, repression of the regulator gene appY, and destabilization of the inheritance of iteron-containing plasmids such as pSC101. This poses the question of the principal biological role of this system. Here it is shown that the periplasmic domain of the E. coli sensor kinase CitA functions as a high-affinity citrate receptor. Two CitA derivatives were purified by affinity chromatography and subjected to binding studies using isothermal titration calorimetry (ITC). One of them, termed CitA215MBP, comprised the N-terminal part of CitA (amino acid residues 1-215), including the two transmembrane helices, and was fused to the amino terminus of the E. coli maltose-binding protein lacking its signal peptide. The second CitA derivative, designated CitAP(Ec), encompassed only the periplasmic domain (amino acid residues 38-177). CitA215MBP bound citrate at 25 degrees C with a K(d) of 0.3 microM and a binding stoichiometry of up to 0.9 in 50 mM sodium phosphate buffer, pH 7. Binding was driven by the enthalpy change (Delta H of -95.7 kJ mol(-1)), whereas the entropy change was not favorable for binding ( T Delta S of -58.6 kJ mol(-1)). ITC experiments with CitAP(Ec) yielded similar K(d) values for citrate (0.15-1.0 microM). Besides citrate, also isocitrate ( K(d) approximately tricarballylate ( K(d) approximately t not malate were bound by CitAP(Ec). The results favor the assumption that the primary biological function of the CitA-CitB system is the regulation of the citrate fermentation genes.

  1. Calcium chloride and tricalcium phosphate effects on the pink color defect in cooked ground and intact turkey breast.

    PubMed

    Sammel, L M; Claus, J R

    2007-12-01

    Calcium chloride (250, 500ppm) was examined for its ability to reduce the pink color defect induced by sodium nitrite (10ppm) and nicotinamide (1.0%) in cooked ground turkey in the presence and absence of sodium tripolyphosphate (0.25, 0.5%) and sodium citrate (0.5, 1.0%). The ability of tricalcium phosphate (0.1-0.5%) to reduce pink cooked color also was evaluated in ground turkey and both calcium chloride and tricalcium phosphate were tested for their effects on pink cooked color in whole breast muscle. The combination of calcium chloride and sodium tripolyphosphate, not calcium chloride alone, was necessary for a reduction in pink cooked color induced by nicotinamide. Subsequently, in the presence of phosphate, both calcium chloride and sodium citrate reduced pink cooked color and were most effective in combination. Tricalcium phosphate also was capable of reducing pink cooked color in ground turkey, however substituting tricalcium phosphate for sodium tripolyphosphate resulted in lower pH and cooking yields. Neither calcium chloride nor tricalcium phosphate was capable of reducing pink cooked color in whole turkey breast. Currently, a combination of sodium tripolyphosphate, calcium chloride, and sodium citrate represents the most suitable means for reducing or preventing the pink color defect in uncured ground turkey.

  2. Regulation of anaerobic citrate metabolism in Klebsiella pneumoniae.

    PubMed

    Bott, M; Meyer, M; Dimroth, P

    1995-11-01

    Three enzymes are specifically required for uptake and catabolism of citrate by Klebsiella pneumoniae under anaerobic conditions: a Na+ -dependent citrate carrier (CitS), citrate lyase (CitDEF), and the Na+ pump oxaloacetate decarboxylase (OadGAB). The corresponding genes are clustered on the chromosome, with the citCDEFG genes located upstream and divergent to the citS-oadGAB genes. We found that expression of citS from its native promoter in Escherichia coli requires the DNA region downstream of oadB. Nucleotide sequence analysis of this region revealed the presence of two adjacent genes, citA and citB. By sequence similarity, the predicted CitA and CitB proteins were identified as members of the two-component regulatory systems. The sensor kinase CitA contained, in the N-terminal half, two putative transmembrane helices which enclosed a presumably periplasmic domain of about 130 amino acids. The C-terminal half of the response regulator CitB harboured a helix-turn-helix motif typical of DNA-binding proteins. K. pneumoniae citB null mutants were unable to grow anaerobically with citrate as the sole carbon and energy source (Cit- phenotype). When cultivated anaerobically with citrate plus glycerol, all of the citrate-specific fermentation enzymes were synthesized in the wild type, but not in the citB mutants. This showed that citS, oadGAB and citDEF required the CitB protein for expression and therefore are part of a regulon. In the wild type, synthesis of CitS, oxaloacetate decarboxylase and citrate lyase was dependent on the presence of citrate, sodium ions and a low oxygen tension. In a citA null mutant which expressed citB constitutively at high levels, none of these signals was required for the formation of the citrate fermentation enzymes. This result suggested that citrate, Na+, and oxygen exerted their regulatory effects via the CitA/CitB system. In the presence of these signals, the citAB gene products induced their own synthesis. The positive

  3. Alkali absorption and citrate excretion in calcium nephrolithiasis

    NASA Technical Reports Server (NTRS)

    Sakhaee, K.; Williams, R. H.; Oh, M. S.; Padalino, P.; Adams-Huet, B.; Whitson, P.; Pak, C. Y.

    1993-01-01

    The role of net gastrointestinal (GI) alkali absorption in the development of hypocitraturia was investigated. The net GI absorption of alkali was estimated from the difference between simple urinary cations (Ca, Mg, Na, and K) and anions (Cl and P). In 131 normal subjects, the 24 h urinary citrate was positively correlated with the net GI absorption of alkali (r = 0.49, p < 0.001). In 11 patients with distal renal tubular acidosis (RTA), urinary citrate excretion was subnormal relative to net GI alkali absorption, with data from most patients residing outside the 95% confidence ellipse described for normal subjects. However, the normal relationship between urinary citrate and net absorbed alkali was maintained in 11 patients with chronic diarrheal syndrome (CDS) and in 124 stone-forming patients devoid of RTA or CDS, half of whom had "idiopathic" hypocitraturia. The 18 stone-forming patients without RTA or CDS received potassium citrate (30-60 mEq/day). Both urinary citrate and net GI alkali absorption increased, yielding a significantly positive correlation (r = 0.62, p < 0.0001), with the slope indistinguishable from that of normal subjects. Thus, urinary citrate was normally dependent on the net GI absorption of alkali. This dependence was less marked in RTA, confirming the renal origin of hypocitraturia. However, the normal dependence was maintained in CDS and in idiopathic hypocitraturia, suggesting that reduced citrate excretion was largely dietary in origin as a result of low net alkali absorption (from a probable relative deficiency of vegetables and fruits or a relative excess of animal proteins).

  4. Chloroquine Phosphate Oral

    MedlinePlus

    Chloroquine phosphate is in a class of drugs called antimalarials and amebicides. It is used to prevent and treat ... Chloroquine phosphate comes as a tablet to take by mouth. For prevention of malaria in adults, one dose is ...

  5. Treatment Efficacy and Safety During Plasma Exchange With Citrate Anticoagulation: A Randomized Study of 4 Versus 15% Citrate.

    PubMed

    Antonic, Manja; Gubensek, Jakob; Buturovic-Ponikvar, Jadranka; Ponikvar, Rafael

    2016-04-01

    In plasma exchange (PE), contrary to dialysis, there is no ultrafiltration, and the volume of anticoagulant contributes to volume overload of the patient and might also reduce PE efficiency through dilution. To reduce the volume of citrate, we compared 4 and 15% citrate anticoagulation protocols in PE in a randomized study, aiming to evaluate PE efficacy, anticoagulation efficiency, and overall safety. In addition to standard biochemical analyses during PE treatments, the elimination rate (ER) of immunoglobulins was calculated to evaluate PE efficacy. Anticoagulation was evaluated by postfilter ionized calcium, visual evaluation of the extracorporeal system, and change in the sieving coefficient (SC) during PE. Accumulation of citrate was determined by calculating the total-to-ionized calcium ratio and measuring the citrate concentration after PE. One hundred forty procedures (70 in each group) were performed in 37 patients. The mean citrate infusion rate was 197 ± 10 mL/h in the 4% and 59 ± 5.5 mL/h in the 15% groups, respectively; the total volume of infused citrate was 502 ± 77 mL versus 164 ± 52 mL (P < 0.001). ER for immunoglobulin G (0.57 ± 0.06 vs. 0.55 ± 0.1, P = 0.18), M, and A were comparable. Ionized calcium was stable during the procedures, and there were no significant side effects. Although postfilter ionized calcium was on the upper limit of the target range (0.41 ± 0.16 vs. 0.37 ± 0.14 mmol/L, P = 0.38), the visual assessment score was excellent, and even a rise in SC was observed during the procedures in both groups. The total-to-ionized calcium ratio was increased in 20 versus 22% of procedures, and citrate concentrations after PE were also similar (1306 ± 441 vs. 1263 ± 405 μmol/L). To conclude, we were unable to show superior PE efficacy in the 15% citrate group, but we significantly reduced the infused volume, which is important in patients with fluid overload. Both

  6. NITRATE REDUCTION BY ZEROVALENT IRON: EFFECTS OF FORMATE, OXALATE, CITRATE, CHLORIDE, SULFATE, BORATE, AND PHOSPHATE

    EPA Science Inventory

    Recent studies have shown that zerovalent iron (Fe0) may potentially be used as a chemical medium in permeable reactive barriers (PRBs) for nitrate remediation in groundwater; however, the effects of commonly found organic and inorganic ligands in soil and sediments on nitrate re...

  7. 77 FR 47370 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Intent To Rescind...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-08

    ..., sodium citrate, and potassium citrate in their unblended forms, whether dry or in solution, and regardless of packaging type. The scope also includes blends of citric acid, sodium citrate, and potassium... acid, sodium citrate, and potassium citrate constitute 40 percent or more, by weight, of the blend....

  8. Identification of two distinct Bacillus subtilis citrate synthase genes.

    PubMed

    Jin, S; Sonenshein, A L

    1994-08-01

    Two distinct Bacillus subtilis genes (citA and citZ) were found to encode citrate synthase isozymes that catalyze the first step of the Krebs cycle. The citA gene was cloned by genetic complementation of an Escherichia coli citrate synthase mutant strain (W620) and was in a monocistronic transcriptional unit. A divergently transcribed gene, citR, could encode a protein with strong similarity to the bacterial LysR family of regulatory proteins. A null mutation in citA had little effect on citrate synthase enzyme activity or sporulation. The residual citrate synthase activity was purified from a citA null mutant strain, and the partial amino acid sequence for the purified protein (CitZ) was determined. The citZ gene was cloned from B. subtilis chromosomal DNA by using a PCR-generated probe synthesized with oligonucleotide primers derived from the partial amino acid sequence of purified CitZ. The citZ gene proved to be the first gene in a tricistronic cluster that also included citC (coding for isocitrate dehydrogenase) and citH (coding for malate dehydrogenase). A mutation in citZ caused a substantial loss of citrate synthase enzyme activity, glutamate auxotrophy, and a defect in sporulation.

  9. Comparison of bismuth citrate and 5-aminosalicylic acid enemas in distal ulcerative colitis: a controlled trial.

    PubMed Central

    Pullan, R D; Ganesh, S; Mani, V; Morris, J; Evans, B K; Williams, G T; Rhodes, J

    1993-01-01

    An enema that contained a complex of bismuth citrate and polyacrylate was compared with 5-aminosalicylic acid (5-ASA) enemas for treatment of distal ulcerative colitis. The multicentre trial involving 63 patients was randomised and double blind with enemas given over four weeks; clinical, sigmoidoscopic, and histological assessments were made. Improvements were seen in both treatment groups. Clinical remission was seen in 18 of 32 patients treated with 5-ASA and 12 of 31 patients treated with bismuth citrate-carbomer (chi 2 1.94; p = 0.16). Sigmoidoscopic remission occurred in 20 of 32 patients in the 5-ASA group and 15 of 31 patients given bismuth (chi 2 1.27; p = 0.26). Improvement of rectal biopsy histology by at least one grade was seen in 16 of 32 patients in the 5-ASA group and 14 of 31 patients with bismuth (chi 2 0.15; p = 0.70). Analysis of covariance gave no significant difference between groups, although there was a trend favouring 5-ASA. There was no evidence of bismuth accumulation during the trial. Bismuth enemas may offer a new therapeutic option in distal ulcerative colitis. PMID:8504970

  10. Kinetics of calcium phosphate nucleation and growth on calcite: implications for predicting the fate of dissolved phosphate species in alkaline soils.

    PubMed

    Wang, Lijun; Ruiz-Agudo, Encarnación; Putnis, Christine V; Menneken, Martina; Putnis, Andrew

    2012-01-17

    Unraveling the kinetics of calcium orthophosphate (Ca-P) precipitation and dissolution is important for our understanding of the transformation and mobility of dissolved phosphate species in soils. Here we use an in situ atomic force microscopy (AFM) coupled with a fluid reaction cell to study the interaction of phosphate-bearing solutions with calcite surfaces. We observe that the mineral surface-induced formation of Ca-P phases is initiated with the aggregation of clusters leading to the nucleation and subsequent growth of Ca-P phases on calcite, at various pH values and ionic strengths relevant to soil solution conditions. A significant decrease in the dissolved phosphate concentration occurs due to the promoted nucleation of Ca-P phases on calcite surfaces at elevated phosphate concentrations and more significantly at high salt concentrations. Also, kinetic data analyses show that low concentrations of citrate caused an increase in the nucleation rate of Ca-P phases. However, at higher concentrations of citrate, nucleation acceleration was reversed with much longer induction times to form Ca-P nuclei. These results demonstrate that the nucleation-modifying properties of small organic molecules may be scaled up to analyze Ca-P dissolution-precipitation processes that are mediated by a more complex soil environment. This in situ observation, albeit preliminary, may contribute to an improved understanding of the fate of dissolved phosphate species in diverse soil systems.

  11. Why nature chose phosphates.

    PubMed

    Westheimer, F H

    1987-03-06

    Phosphate esters and anhydrides dominate the living world but are seldom used as intermediates by organic chemists. Phosphoric acid is specially adapted for its role in nucleic acids because it can link two nucleotides and still ionize; the resulting negative charge serves both to stabilize the diesters against hydrolysis and to retain the molecules within a lipid membrane. A similar explanation for stability and retention also holds for phosphates that are intermediary metabolites and for phosphates that serve as energy sources. Phosphates with multiple negative charges can react by way of the monomeric metaphosphate ion PO3- as an intermediate. No other residue appears to fulfill the multiple roles of phosphate in biochemistry. Stable, negatively charged phosphates react under catalysis by enzymes; organic chemists, who can only rarely use enzymatic catalysis for their reactions, need more highly reactive intermediates than phosphates.

  12. Magnetic nanoparticles coated with cyclodextrins and citrate for irinotecan delivery.

    PubMed

    Monteiro, Ana P F; Caminhas, Larissa D; Ardisson, José D; Paniago, Roberto; Cortés, Maria E; Sinisterra, Rubén D

    2017-05-01

    In the present work, we study the role of different components in the formation of more stable iron oxide magnetic nanoparticles (MNPs): β-cyclodextrin (BCD), 2-hydroxypropyl-β-cyclodextrin (HP) and citrate anion. MNPs formulations were characterized by FTIR, particles size measurements, zeta potential based on dynamic light scattering principle technique, X-ray powder pattern diffraction, XPS spectroscopy, transmission electron microscopy and thermogravimetric analysis. The results showed that cyclodextrins and citrate plays a key role in order to obtain a lower size of coated MNPs and proved to be an efficient strategy to obtain a more stable colloidal dispersion, avoiding the nanoparticles oxidation, enhancing the irinotecan incorporation and release. Furthermore, citrate-coated BCD-MNPs showed the same cytotoxicity of the free IRI.

  13. Utility of Aspergillus niger citrate synthase promoter for heterologous expression.

    PubMed

    Dave, Kashyap; Punekar, Narayan S

    2011-09-10

    Citrate synthase is a central player in the acidogenic metabolism of Aspergillus niger. The 5' upstream sequence (0.9kb DNA) of citrate synthase gene (citA) from A. niger NCIM 565 was analyzed and its promoter function demonstrated through the heterologous expression of two proteins. The cloned citrate synthase promoter (PcitA) sequence was able to express bar coding sequence thereby conferring phosphinothricin resistance. This sequence was further analyzed by systematic deletions to define an effective but compact functional promoter. The PcitA driven egfp expression showed that PcitA was active in all differentiation cell-stages of A. niger. EGFP expression was highest on non-repressible carbon sources like acetate and glycerol. Mycelial EGFP levels increased during acidogenic growth suggesting that PcitA is functional throughout this cultivation. A. niger PcitA is the first Krebs cycle gene promoter used to express heterologous proteins in filamentous fungi.

  14. Peroxisomal and mitochondrial citrate synthase in CAM plants.

    PubMed

    Zafra, M F; Segovia, J L; Alejandre, M J; García-Peregrín, E

    1981-12-01

    Citrate synthase wa studied for the first time in peroxisomes and mitochondria of crassulacean acid metabolism plants. Cellular organelles were isolated from Agave americana leaves by sucrose density gradient centrifugation and characterized by the use of catalase and cytochrome oxidase as marker enzymes, respectively. 48,000 X g centrifugation caused the breakdown of the cellular organelles. The presence of a glyoxylate cycle enzyme (citrate synthase) and a glycollate pathway enzyme (catalase) in the same organelles, besides the absence of another glyoxalate cycle enzyme (malate synthase) is reported for the first time, suggesting that peroxisomal and glyoxysomal proteins are synthesized at the same time and housed in he same organelle.

  15. Supplementation of total parenteral nutrition solutions with ferrous citrate.

    PubMed

    Sayers, M H; Johnson, D K; Schumann, L A; Ivey, M F; Young, J H; Finch, C A

    1983-01-01

    Daily infusion of a total parenteral nutrition (TPN) formulation containing 1 liter of 5.5% Travasol provides less than 0.1 milligrams of iron. By comparison, a formulation which includes a liter of 10% Travamin provides 2 milligrams of iron per day. To meet iron requirements in patients infusing formulations containing Travasol, iron was added as ferrous citrate. In in virto experiments, 74% of this iron was available to transferrin. In seven patients in whom in vivo availability was tested by red cell incorporation, the mean availability was 81%. Ferrous citrate is recommended as a safe, effective additive to TPN solutions for adult patients requiring iron supplements.

  16. Influence of caffeine and sodium citrate ingestion on 1,500-m exercise performance in elite wheelchair athletes: a pilot study.

    PubMed

    Flueck, Joelle Leonie; Mettler, Samuel; Perret, Claudio

    2014-06-01

    The aim of this study was to investigate whether caffeine and/or sodium citrate have an ergogenic effect on the 1,500-m exercise performance in elite wheelchair athletes. A placebo-controlled, randomized, cross-over and double-blind study design was conducted with the four treatments placebo, caffeine, sodium citrate and the combination of caffeine and sodium citrate. Nine healthy, elite wheelchair-racing athletes (median: [min; max] age: 28 y [23; 54]; height: 173 cm [165; 188]; weight: 62.9 kg [48.9; 68.4], category T53/54) completed the study. All athletes were national team members, including several Paralympic Games, World and European Championship medalists. The athletes performed a 1,500-m time trial four times on a wheelchair training roller. Time to complete 1,500-m, pH, bicarbonate and sodium concentration as well as lactate concentration were measured. The time to complete 1,500-m was not significantly different between the four treatments (placebo: 170.6 s [141.7; 232.0]; caffeine: 179.5 s [134.8; 239.6]; sodium citrate: 178.3 s [136.4; 247.1]; combination: 177.6 s [136.1; 256.2]). However, pH and bicarbonate concentrations were significantly increased with sodium citrate ingestion compared with placebo. Moreover, maximal lactate concentrations were significantly higher in the caffeine and the combination treatment compared with placebo. The supplementation with sodium citrate and/or caffeine did not provide an ergogenic effect on the 1,500-m exercise performance in wheelchair elite athletes.

  17. Phosphate, inositol and polyphosphates.

    PubMed

    Livermore, Thomas M; Azevedo, Cristina; Kolozsvari, Bernadett; Wilson, Miranda S C; Saiardi, Adolfo

    2016-02-01

    Eukaryotic cells have ubiquitously utilized the myo-inositol backbone to generate a diverse array of signalling molecules. This is achieved by arranging phosphate groups around the six-carbon inositol ring. There is virtually no biological process that does not take advantage of the uniquely variable architecture of phosphorylated inositol. In inositol biology, phosphates are able to form three distinct covalent bonds: phosphoester, phosphodiester and phosphoanhydride bonds, with each providing different properties. The phosphoester bond links phosphate groups to the inositol ring, the variable arrangement of which forms the basis of the signalling capacity of the inositol phosphates. Phosphate groups can also form the structural bridge between myo-inositol and diacylglycerol through the phosphodiester bond. The resulting lipid-bound inositol phosphates, or phosphoinositides, further expand the signalling potential of this family of molecules. Finally, inositol is also notable for its ability to host more phosphates than it has carbons. These unusual organic molecules are commonly referred to as the inositol pyrophosphates (PP-IPs), due to the presence of high-energy phosphoanhydride bonds (pyro- or diphospho-). PP-IPs themselves constitute a varied family of molecules with one or more pyrophosphate moiety/ies located around the inositol. Considering the relationship between phosphate and inositol, it is no surprise that members of the inositol phosphate family also regulate cellular phosphate homoeostasis. Notably, the PP-IPs play a fundamental role in controlling the metabolism of the ancient polymeric form of phosphate, inorganic polyphosphate (polyP). Here we explore the intimate links between phosphate, inositol phosphates and polyP, speculating on the evolution of these relationships.

  18. Concentration-dependent Sildenafil citrate (Viagra) effects on ROS production, energy status, and human sperm function.

    PubMed

    Sousa, Maria Inês; Amaral, Sandra; Tavares, Renata Santos; Paiva, Carla; Ramalho-Santos, João

    2014-04-01

    Literature regarding the effects of sildenafil citrate on sperm function remains controversial. In the present study, we specifically wanted to determine if mitochondrial dysfunction, namely membrane potential, reactive oxygen species production, and changes in energy content, are involved in in vitro sildenafil-induced alterations of human sperm function. Sperm samples of healthy men were incubated in the presence of 0.03, 0.3, and 3 μM sildenafil citrate in a phosphate buffered saline (PBS)-based medium for 2, 3, 12, and 24 hours. Sperm motility and viability were evaluated and mitochondrial function, i.e., mitochondrial membrane potential and mitochondrial superoxide production were assessed using flow-cytometry. Additionally, adenosine triphosphate (ATP) levels were determined by high performance liquid chromatography (HPLC) analysis. Results show a decrease in sperm motility correlated with the level of mitochondria-generated superoxide, without a visible effect on mitochondrial membrane potential or viability upon exposure to sildenafil. The effect on both motility and superoxide production was higher for the intermediate concentration of sildenafil (0.3 µM) indicating that the in vitro effects of sildenafil on human sperm do not vary linearly with drug concentration. Adenosine triphosphate levels also decreased following sildenafil exposure, but this decrease was only detected after a decrease in motility was already evident. These results suggest that along with the level of ATP and mitochondrial function other factors are involved in the early sildenafil-mediated decline in sperm motility. However, the further decrease in ATP levels and increase in mitochondria-generated reactive oxygen species after 24 hours of exposure might further contribute towards declining sperm motility.

  19. Phosphate taxis in Pseudomonas aeruginosa.

    PubMed

    Kato, J; Ito, A; Nikata, T; Ohtake, H

    1992-08-01

    Pseudomonas aeruginosa was shown to be attracted to phosphate. The chemotactic response was induced by phosphate starvation. The specificity of chemoreceptors for phosphate was high so that no other tested phosphorus compounds elicited a chemotactic response as strong as that elicited by phosphate. Competition experiments showed that the chemoreceptors for phosphate appeared to be different from those for the common amino acids. Mutants constitutive for alkaline phosphatase showed the chemotactic response to phosphate regardless of whether the cells were starved for phosphate.

  20. 40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  1. 40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  2. 40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  3. 40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  4. 40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  5. 40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  6. 40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  7. 40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  8. Development of Injectable Citrate-Based Bioadhesive Bone Implants

    PubMed Central

    Xie, Denghui; Guo, Jinshan; Mehdizadeh, Mohammadreza; Tran, Richard T.; Chen, Ruisong; Sun, Dawei; Qian, Guoying; Jin, Dadi; Bai, Xiaochun; Yang, Jian

    2014-01-01

    Injectable bone implants have been widely used in bone tissue repairs including the treatment of comminuted bone fractures (CBF). However, most injectable bone implants are not suitable for the treatment of CBF due to their weak tissue adhesion strengths and minimal osteoinduction. Citrate has been recently reported to promote bone formation through enhanced bioceramic integration and osteoinductivity. Herein, a novel injectable citrate-based mussel-inspired bioadhesive hydroxyapatite (iCMBA/HA) bone substitute was developed for CBF treatment. iCMBA/HA can be set within 2–4 minutes and the as-prepared (wet) iCMBA/HA possess low swelling ratios, compressive mechanical strengths of up to 3.2±0.27 MPa, complete degradation in 30 days, suitable biocompatibility, and osteoinductivity. This is also the first time to demonstrate that citrate supplementation in osteogenic medium and citrate released from iCMBA/HA degradation can promote the mineralization of osteoblastic committed human mesenchymal stem cells (hMSCs). In vivo evaluation of iCMBA/HA in a rabbit comminuted radial fracture model showed significantly increased bone formation with markedly enhanced three-point bending strength compared to the negative control. Neovascularization and bone ingrowth as well as highly organized bone formation were also observed showing the potential of iCMBA/HA in treating CBF. PMID:25580247

  9. 21 CFR 522.300 - Carfentanil citrate injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Carfentanil citrate injection. 522.300 Section 522.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  10. 21 CFR 522.300 - Carfentanil citrate injection.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Carfentanil citrate injection. 522.300 Section 522.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  11. 21 CFR 522.300 - Carfentanil citrate injection.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carfentanil citrate injection. 522.300 Section 522.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  12. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  13. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  14. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  15. 21 CFR 573.560 - Iron ammonium citrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Iron ammonium citrate. 573.560 Section 573.560 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS...

  16. 21 CFR 520.623 - Diethylcarbamazine citrate, oxibendazole chewable tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate, oxibendazole chewable tablets. 520.623 Section 520.623 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND... during heartworm season. For free-choice feeding or broken and placed on or mixed with feed. Do not...

  17. 21 CFR 520.622 - Diethylcarbamazine citrate oral dosage forms.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Diethylcarbamazine citrate oral dosage forms. 520.622 Section 520.622 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS §...

  18. 21 CFR 522.800 - Droperidol and fentanyl citrate injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Droperidol and fentanyl citrate injection. 522.800 Section 522.800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL...

  19. 21 CFR 522.300 - Carfentanil citrate injection.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Carfentanil citrate injection. 522.300 Section 522.300 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS §...

  20. 21 CFR 522.800 - Droperidol and fentanyl citrate injection.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Droperidol and fentanyl citrate injection. 522.800 Section 522.800 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL...

  1. Complex transcriptional regulation of citrate metabolism in Clostridium perfringens.

    PubMed

    Yuan, Yonghui; Ohtani, Kaori; Yoshizawa, Satoko; Shimizu, Tohru

    2012-02-01

    A Gram-positive, spore-forming bacterium, Clostridium perfringens, possesses genes for citrate metabolism, which might play an important role in the utilization of citrate as a sole carbon source. In this study, we identified a chromosomal citCDEFX-mae-citS operon in C. perfringens strain 13, which is transcribed on three mRNAs of different sizes. Expression of the cit operon was significantly induced when 5 mM extracellular citrate was added to the growth medium. Most interestingly, three regulatory systems were found to be involved in the regulation of the expression of cit genes: 1) the two upstream divergent genes citG and citI; 2) two different two-component regulatory systems, CitA/CitB (TCS6 consisted of CPE0531/CPE0532) and TCS5 (CPE0518/CPE0519); and 3) the global two-component VirR/VirS-VR-RNA regulatory system known to regulate various genes for toxins and degradative enzymes. Our results suggest that in C. perfringens the citrate metabolism might be strictly controlled by a complex regulatory system.

  2. 21 CFR 184.1296 - Ferric ammonium citrate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE... brown or garnet red scales or granules or as a brownish-yellowish powder. (2) Ferric ammonium citrate... occurs as thin transparent green scales, as granules, as a powder, or as transparent green crystals....

  3. 21 CFR 184.1296 - Ferric ammonium citrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... FOR HUMAN CONSUMPTION (CONTINUED) DIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE... brown or garnet red scales or granules or as a brownish-yellowish powder. (2) Ferric ammonium citrate... occurs as thin transparent green scales, as granules, as a powder, or as transparent green crystals....

  4. 40 CFR 721.7286 - Amines, N-tallowalkyltripropylenetetra-, citrates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, N-tallowalkyltripropylenetetra... Specific Chemical Substances § 721.7286 Amines, N-tallowalkyltripropylenetetra-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  5. 40 CFR 721.7285 - Amines, N-cocoalkyltrimethylenedi-, citrates.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Amines, N-cocoalkyltrimethylenedi... Specific Chemical Substances § 721.7285 Amines, N-cocoalkyltrimethylenedi-, citrates. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified as amines,...

  6. 21 CFR 520.622d - Diethylcarbamazine citrate capsules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Diethylcarbamazine citrate capsules. (a) Specifications. Each capsule contains 12.5, 50, 200, or 400 milligrams (mg... dogs—(1) Amount/indications for use. 3 mg per pound (/lb) body weight daily for prevention of heartworm disease (Dirofilaria immitis); 25 to 50 mg/lb body weight in a single dose as an aid in the treatment...

  7. 21 CFR 520.622d - Diethylcarbamazine citrate capsules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Diethylcarbamazine citrate capsules. (a) Specifications. Each capsule contains 12.5, 50, 200, or 400 milligrams (mg... dogs—(1) Amount/indications for use. 3 mg per pound (/lb) body weight daily for prevention of heartworm disease (Dirofilaria immitis); 25 to 50 mg/lb body weight in a single dose as an aid in the treatment...

  8. 75 FR 14491 - Listing of Color Additives Exempt From Certification; Bismuth Citrate

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-26

    ... level of bismuth citrate as a color additive in cosmetics intended for coloring hair on the scalp. This... citrate as a color additive in cosmetics intended for coloring hair on the scalp from 0.5 percent (weight... bismuth citrate in cosmetics intended for coloring scalp hair to 2.0 percent (w/v) with no changes to...

  9. 78 FR 63228 - Determination That Potassium Citrate, 10 Milliequivalents/Packet and 20 Milliequivalents/Packet...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-23

    ... HUMAN SERVICES Food and Drug Administration Determination That Potassium Citrate, 10 Milliequivalents...) has determined that Potassium Citrate, 10 milliequivalents/packet (mEq/packet) and 20 mEq/ packet, was... approve abbreviated new drug applications (ANDAs) for Potassium Citrate, 10 mEq/packet and 20...

  10. 78 FR 34338 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-07

    ... International Trade Administration Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of... administrative review of the antidumping duty order on citric acid and certain citrate salts (citric acid) from... is citric acid and certain citrate salts. The product is currently classified in the...

  11. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, T.

    1997-02-18

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

  12. Zinc phosphate conversion coatings

    DOEpatents

    Sugama, Toshifumi

    1997-01-01

    Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

  13. Soluble phosphate fertilizer production using acid effluent from metallurgical industry.

    PubMed

    Mattiello, Edson M; Resende Filho, Itamar D P; Barreto, Matheus S; Soares, Aline R; Silva, Ivo R da; Vergütz, Leonardus; Melo, Leônidas C A; Soares, Emanuelle M B

    2016-01-15

    Preventive and effective waste management requires cleaner production strategies and technologies for recycling and reuse. Metallurgical industries produce a great amount of acid effluent that must be discarded in a responsible manner, protecting the environment. The focus of this study was to examine the use of this effluent to increase reactivity of some phosphate rocks, thus enabling soluble phosphate fertilizer production. The effluent was diluted in deionized water with the following concentrations 0; 12.5; 25; 50; 75% (v v(-1)), which were added to four natural phosphate rocks: Araxá, Patos, Bayovar and Catalão and then left to react for 1 h and 24 h. There was an increase in water (PW), neutral ammonium citrate (PNAC) and citric acid (PCA) soluble phosphorus fractions. Such increases were dependent of rock type while the reaction time had no significant effect (p < 0.05) on the chemical and mineralogical phosphate characteristics. Phosphate fertilizers with low toxic metal concentrations and a high level of micronutrients were produced compared to the original natural rocks. The minimum amount of total P2O5, PNAC and PW, required for national legislation for phosphate partially acidulated fertilizer, were met when using Catalão and the effluent at the concentration of 55% (v v(-1)). Fertilizer similar to partially acidulated phosphate was obtained when Bayovar with effluent at 37.5% (v v(-1)) was used. Even though fertilizers obtained from Araxá and Patos did not contain the minimum levels of total P2O5 required by legislation, they can be used as a nutrient source and for acid effluent recycling and reuse.

  14. Identification of three relationships linking cadmium accumulation to cadmium tolerance and zinc and citrate accumulation in lettuce.

    PubMed

    Zorrig, Walid; Rouached, Aïda; Shahzad, Zaigham; Abdelly, Chedly; Davidian, Jean-Claude; Berthomieu, Pierre

    2010-10-15

    Lettuce (Lactuca sativa) is a plant species that shows high accumulation of cadmium, a toxic heavy metal. Lettuce is therefore a good model both for identifying determinants controlling cadmium accumulation in plant tissues and for developing breeding strategies aimed at limiting cadmium accumulation in edible tissues. In this work, 14-day-old plants from three lettuce varieties were grown for 8 days on media supplemented with cadmium concentrations ranging from 0 to 50 microM. Growth, as well as Cd(2+), Zn(2+), K(+), Ca(2+), NO(3)(-), SO(4)(2-), Cl(-), phosphate, malate and citrate root an shoot contents were analyzed. The three lettuce varieties Paris Island Cos, Red Salad Bowl and Kordaat displayed differential abilities to accumulate cadmium in roots and shoots, Paris Island Cos displaying the lowest cadmium content and Kordaat the highest. From the global analysis of the three varieties, three main trends were identified. First, a common negative correlation linked cadmium tissue content and relative dry weight reduction in response to cadmium treatments in the three varieties. Second, increasing cadmium concentration in the culture medium resulted in a parallel increase in zinc tissue content in all lettuce varieties. A common strong positive correlation between cadmium and zinc contents was observed for all varieties. This suggested that systems enabling zinc and cadmium transport were induced by cadmium. Finally, the cadmium treatments had a contrasting effect on anion contents in tissues. Interestingly, citrate content in shoots was correlated with cadmium translocation from roots to shoots, suggesting that citrate might play a role in cadmium transport in the xylem vessels. Altogether, these results shed light on three main strategies developed by lettuce to cope with cadmium, which could help to develop breeding strategies aimed at limiting cadmium accumulation in lettuce.

  15. CADMIUM PHOSPHATE GLASS

    DOEpatents

    Carpenter, H.W.; Johnson, P.D.

    1963-04-01

    A method of preparing a cadmium phosphate glass that comprises providing a mixture of solid inorganic compounds of cadmuim and phosphate having vaporizable components and heating the resulting composition to a temperature of at least 850 un. Concent 85% C is presented. (AEC)

  16. Modification by food of the calcium absorbability and physicochemical effects of calcium citrate

    NASA Technical Reports Server (NTRS)

    Wabner, C. L.; Pak, C. Y.

    1992-01-01

    The food-calcium (Ca) interaction was examined in 12 healthy women (mean age 38 years) maintained on a constant metabolic diet. They underwent three phases of study, comprised of control (no Ca), Ca citrate (1 g Ca/day) during meals, and Ca citrate separately from meals. Each phase was 7 days in length and two 24-hour urine samples were collected on days 6 and 7. The rise from the control phase in urinary Ca was slightly more prominent when Ca citrate was given with meals than without (68 and 62%, respectively). The fall in urinary phosphorus was equivalent at about 25% between Ca citrate phases. The rise in urinary citrate and pH and the decline in urinary ammonium were more prominent when Ca citrate was given with meals; however, the changes were small or nonsignificant. The urinary saturation of Ca oxalate, brushite or monosodium urate did not differ between the two Ca citrate phases. There was a nonsignificant rise in serum iron during Ca citrate phases. The results suggest that: 1) dissolution and absorption of Ca citrate might be slightly greater when given with food than without; 2) that the ability of Ca citrate to attenuate crystallization of stone-forming Ca salts in urine is not modified by food; and 3) that Ca citrate may not impair iron absorption from food.

  17. High lipid accumulation in Yarrowia lipolytica cultivated under double limitation of nitrogen and magnesium.

    PubMed

    Bellou, S; Triantaphyllidou, I-E; Mizerakis, P; Aggelis, G

    2016-09-20

    Yarrowia lipolytica cultivated under double nitrogen and magnesium limitation, but not under single nitrogen or single magnesium limitation, produced 12.2g/l biomass containing 47.5% lipids, which corresponds to a lipid production 5.8g/l. These yields are the higher described in the literature for wild strains of Y. lipolytica. Transcription of ACL1 and ACL2, encoding for ATP-citrate lyase (ATP:CL) was observed even under non-oleaginous conditions but high activity of ATP:CL was only detected under oleaginous conditions induced by low or zero activity of NAD(+) dependent isocitrate dehydrogenase. The low activity of malic enzyme (ME), a NADPH donor in typical oleaginous microorganisms, indicated that ME may not be implicated in lipid biosynthesis in this yeast, and NADPH may be provided by the pentose phosphate pathway (PPP). These findings underline the essential role of magnesium in lipogenesis, which is currently quite unexplored. The presence of organic nitrogen in low concentrations during lipogenesis was also required, and this peculiarity was probably related with the PPP functioning, being the NADPH donor of lipogenic machinery in Y. lipolytica.

  18. Characterization of CitA-CitB signal transduction activating genes involved in anaerobic citrate catabolism in Escherichia coli.

    PubMed

    Yamamoto, Kaneyoshi; Matsumoto, Fumika; Minagawa, Shu; Oshima, Taku; Fujita, Nobuyuki; Ogasawara, Naotake; Ishihama, Akira

    2009-02-01

    In Escherichia coli, CitA is a membrane-associated sensor histidine kinase that phosphorylates CitB, the response regulator. It is predicated to play a key role in anaerobic citrate catabolism. The citrate-binding site in CitA is located within its periplasmic domain, while the cytoplasmic domain (CitA-C) is involved in autophosphorylation. We found that autophosphorylation in vitro of CitA-C was induced by DTT. Using the whole set of CitA-C derivatives containing Cys-Ala substitution(s), Cys at 529 was found to be essential to the redox-sensing of autophosphorylation. The phosphorylated CitA-C transferred a phosphate to CitB. DNase-I footprinting assay indicated that CitB specifically bound on the intergenic region between the citA and citC genes. These results characterize the molecular mechanism of the CitA-CitB signal transduction system in E. coli.

  19. Changes in phosphorylation of adenosine phosphate and redox state of nicotinamide-adenine dinucleotide (phosphate) in Geobacter sulfurreducens in response to electron acceptor and anode potential variation.

    PubMed

    Rose, Nicholas D; Regan, John M

    2015-12-01

    Geobacter sulfurreducens is one of the dominant bacterial species found in biofilms growing on anodes in bioelectrochemical systems. The intracellular concentrations of reduced and oxidized forms of nicotinamide-adenine dinucleotide (NADH and NAD(+), respectively) and nicotinamide-adenine dinucleotide phosphate (NADPH and NADP(+), respectively) as well as adenosine triphosphate (ATP), adenosine diphosphate (ADP), and adenosine monophosphate (AMP) were measured in G. sulfurreducens using fumarate, Fe(III)-citrate, or anodes poised at different potentials (110, 10, -90, and -190 mV (vs. SHE)) as the electron acceptor. The ratios of CNADH/CNAD+ (0.088±0.022) and CNADPH/CNADP+ (0.268±0.098) were similar under all anode potentials tested and with Fe(III)-citrate (reduced extracellularly). Both ratios significantly increased with fumarate as the electron acceptor (0.331±0.094 for NAD and 1.96±0.37 for NADP). The adenylate energy charge (the fraction of phosphorylation in intracellular adenosine phosphates) was maintained near 0.47 under almost all conditions. Anode-growing biofilms demonstrated a significantly higher molar ratio of ATP/ADP relative to suspended cultures grown on fumarate or Fe(III)-citrate. These results provide evidence that the cellular location of reduction and not the redox potential of the electron acceptor controls the intracellular redox potential in G. sulfurreducens and that biofilm growth alters adenylate phosphorylation.

  20. Citrate sensing by the C4-dicarboxylate/citrate sensor kinase DcuS of Escherichia coli: binding site and conversion of DcuS to a C4-dicarboxylate- or citrate-specific sensor.

    PubMed

    Krämer, J; Fischer, J D; Zientz, E; Vijayan, V; Griesinger, C; Lupas, A; Unden, G

    2007-06-01

    The histidine protein kinase DcuS of Escherichia coli senses C(4)-dicarboxylates and citrate by a periplasmic domain. The closely related sensor kinase CitA binds citrate, but no C(4)-dicarboxylates, by a homologous periplasmic domain. CitA is known to bind the three carboxylate and the hydroxyl groups of citrate by sites C1, C2, C3, and H. DcuS requires the same sites for C(4)-dicarboxylate sensing, but only C2 and C3 are highly conserved. It is shown here that sensing of citrate by DcuS required the same sites. Binding of citrate to DcuS, therefore, was similar to binding of C(4)-dicarboxylates but different from that of citrate binding in CitA. DcuS could be converted to a C(4)-dicarboxylate-specific sensor (DcuS(DC)) by mutating residues of sites C1 and C3 or of some DcuS-subtype specific residues. Mutations around site C1 aimed at increasing the size and accessibility of the site converted DcuS to a citrate-specific sensor (DcuS(Cit)). DcuS(DC) and DcuS(Cit) had complementary effector specificities and responded either to C(4)-dicarboxylates or to citrate and mesaconate. The results imply that DcuS binds citrate (similar to the C(4)-dicarboxylates) via the C(4)-dicarboxylate part of the molecule. Sites C2 and C3 are essential for binding of two carboxylic groups of citrate or of C(4)-dicarboxylates; sites C1 and H are required for other essential purposes.

  1. Trisodium citrate, Na3(C6H5O7)

    PubMed Central

    Rammohan, Alagappa; Kaduk, James A.

    2016-01-01

    The crystal structure of anhydrous tris­odium citrate, Na3(C6H5O7), has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional theory (DFT). There are two independent five-coordinate Na+ and one six-coordinate Na+ cations in the asymmetric unit. The [NaO5] and [NaO6] polyhedra share edges and corners to form a three-dimensional framework. There are channels parallel to the a and b axes in which the remainder of the citrate anions reside. The only hydrogen bonds are an intra­molecular one between the hy­droxy group and one of the terminal carboxyl­ate O atoms and an intermolecular one between a methylene group and the hydroxyl O atom. PMID:27308044

  2. Calcium citrate for vulvar vestibulitis. A case report.

    PubMed

    Solomons, C C; Melmed, M H; Heitler, S M

    1991-12-01

    A woman had suffered from vulvar vestibulitis (vulvodynia) for four years. Pain from the disorder had disrupted her ability to function at work and home as well as sexually. An initial full range of treatments, including multiple operations, had produced no relief. Examination of the urine for evidence of excess oxalate, which has been shown to cause epithelial reactions similar to those found in vulvodynia, showed periodic hyperoxaluria and pH elevations related to the symptoms. Calcium citrate was given to modify the oxalate crystalluria. The symptoms were significantly reduced in three months, and the patient was pain free after one year. She was able to resume normal work, family, sexual and recreational activities. Withdrawal of the calcium citrate resulted in a return of the symptoms; reinstitution alleviated them. These findings suggest that further study of individualized metabolic factors that may underlie vulvodynia is warranted.

  3. Clomiphene citrate and its effects upon ovulation and estrogen.

    PubMed

    Shirai, E; Iizuka, R; Notake, Y

    1972-05-01

    This paper reports a clinical evaluation of the mechanism of action of clomiphene citrate and describes selection of the most responsive patients. Patients were 121 women, aged 21-37 years, who desired pregnancy. Their infertility was diagnosed as being due to anovulation. Primary amenorrhea or special endocrine disorders were not present. All the women who had no vaginal bleeding for more than 2 months were diagnosed amenorrhea and treated with 65 mg of progesterone capronate intramuscularly. They were then divided into two subgroups on the basis of the presence or absence of vaginal bleeding within 2 weeks. Clinical studies included: basal body temperature charts; daily vaginal smears evaluated by the ink acidophilic stain index (ISI); cervical mucus evaluated by amount, spresence of spinnbarkeit, and ferning; 24-hour urines examined for estrogen and total gonadotropic activity; and a pregnanediol determination. Each group received daily 50 mg doses of clomiphene citrate for 5 days. Estrogen inhibiting effect of the drug was suggested by vaginal cytology and the disappearance of ferning and decrease in quantity of cervical mucus. However, the excretion of the total urinary estrogen was increased in ovulatory cases (81 of the 121 patients). In 17 patients having no bleeding within 2 weeks after progesterone injection no ovulation could be induced. In patients with withdrawal flow 54 of 70 achieved ovulation. Of 37 patients with previous anovulatory bleeding 27 achieved ovulation. There were 11 of the 121 who became pregnant. In those with early ovulation the antiestrogen effect is believed to be in the hypothalamus and pituitary bringing about the estrogen surge and stimulating LH secretion. In those with later ovulation the antiestrogenic effect increased FSH secretion followed by ovulation. The type of patient most likely to respond to clomiphene citrate is one with nearly normal pituitary-gonadal axis. Inducing withdrawal bleeding with progesterone in those

  4. Severe citrate toxicity complicating volunteer apheresis platelet donation.

    PubMed

    Bell, A M; Nolen, J D L; Knudson, C M; Raife, T J

    2007-02-01

    We report a case of severe citrate toxicity during volunteer donor apheresis platelet collection. The donor was a 40-year-old female, first-time apheresis platelet donor. Past medical history was remarkable for hypertension, hyperlipidemia, and depression. Reported medications included bumetanide, pravastatin, and paroxetine. Thirty minutes from the start of the procedure, the donor noted tingling around the mouth, hands, and feet. She then very rapidly developed acute onset of severe facial and extremity tetany. Empirical treatment with intravenous calcium gluconate was initiated, and muscle contractions slowly subsided over approximately 10 to 15 minutes. The events are consistent with a severe reaction to calcium chelation by sodium citrate anticoagulant resulting in symptomatic systemic hypocalcemia. Upon additional retrospective analysis, it was noted that bumetanide is a loop diuretic that may cause significant hypocalcemia. We conclude that careful screening for medications and underlying conditions predisposing to hypocalcemia is recommended to help prevent severe reactions due to citrate toxicity. Laboratory measurement of pre-procedure serum calcium levels in selected donors may identify cases requiring heightened vigilance. The case also illustrates the importance of maintaining preparedness for managing rare but serious reactions in volunteer apheresis blood donors.

  5. Formation of apatitic calcium phosphates in a Na-K-phosphate solution of pH 7.4.

    PubMed

    Tas, A C; Aldinger, F

    2005-02-01

    Poorly crystalline, apatitic calcium phosphate powders have been synthesized by slowly adding a Na- and K-containing reference phosphate solution with a pH value of 7.4 to an aqueous calcium nitrate solution at 37 degrees C. Nano-particulated apatitic powders obtained were shown to contain small amounts of Na and K, which render them more similar in chemical composition to that of the bone mineral. Precipitated and dried powders were found to exhibit self-hardening cement properties when kneaded in a mortar with a sodium citrate- and sodium phosphate-containing starter solution. The same phosphate solution used in powder synthesis was found to be able to partially convert natural, white and translucent marble pieces of calcite (CaCO3) into calcium-deficient hydroxyapatite upon aging the samples in that solution for 3 days at 60 degrees C. Sample characterization was performed by using scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, inductively-coupled plasma atomic emission spectroscopy, and simultaneous thermogravimetry and differential thermal analysis.

  6. CitI, a Transcription Factor Involved in Regulation of Citrate Metabolism in Lactic Acid Bacteria†

    PubMed Central

    Martin, Mauricio G.; Magni, Christian; de Mendoza, Diego; López, Paloma

    2005-01-01

    A large variety of lactic acid bacteria (LAB) can utilize citrate under fermentative conditions. Although much information concerning the metabolic pathways leading to citrate utilization by LAB has been gathered, the mechanisms regulating these pathways are obscure. In Weissella paramesenteroides (formerly called Leuconostoc paramesenteroides), transcription of the citMDEFCGRP citrate operon and the upstream divergent gene citI is induced by the presence of citrate in the medium. Although genetic experiments have suggested that CitI is a transcriptional activator whose activity can be modulated in response to citrate availability, specific details of the interaction between CitI and DNA remained unknown. In this study, we show that CitI recognizes two A+T-rich operator sites located between citI and citM and that the DNA-binding affinity of CitI is increased by citrate. Subsequently, this citrate signal propagation leads to the activation of the cit operon through an enhanced recruitment of RNA polymerase to its promoters. Our results indicate that the control of CitI by the cellular pools of citrate provides a mechanism for sensing the availability of citrate and adjusting the expression of the cit operon accordingly. In addition, this is the first reported example of a transcription factor directly functioning as a citrate-activated switch allowing the cell to optimize the generation of metabolic energy. PMID:16030208

  7. Exogenous citrate impairs glucose tolerance and promotes visceral adipose tissue inflammation in mice.

    PubMed

    Leandro, João G B; Espindola-Netto, Jair M; Vianna, Maria Carolina F; Gomez, Lilian S; DeMaria, Thaina M; Marinho-Carvalho, Monica M; Zancan, Patricia; Paula Neto, Heitor A; Sola-Penna, Mauro

    2016-03-28

    Overweight and obesity have become epidemic worldwide and are linked to sedentary lifestyle and the consumption of processed foods and drinks. Citrate is a metabolite that plays central roles in carbohydrate and lipid metabolism. In addition, citrate is the additive most commonly used by the food industry, and therefore is highly consumed. Extracellular citrate can freely enter the cells via the constitutively expressed plasma membrane citrate transporter. Within the cytosol, citrate is readily metabolised by ATP-citrate lyase into acetyl-CoA - the metabolic precursor of endogenously produced lipids and cholesterol. We therefore hypothesised that the citrate ingested from processed foods and drinks could contribute to increased postprandial fat production and weight gain. To test our hypothesis, we administered citrate to mice through their drinking water with or without sucrose and monitored their weight gain and other metabolic parameters. Our results showed that mice receiving citrate or citrate+sucrose did not show increased weight gain or an increase in the weight of the liver, skeletal muscles or adipose tissues (AT). Moreover, the plasma lipid profiles (TAG, total cholesterol, LDL and HDL) were similar across all groups. However, the group receiving citrate+sucrose showed augmented fasting glycaemia, glucose intolerance and the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6 and IL-10) in their AT. Therefore, our results suggest that citrate consumption contributes to increased AT inflammation and altered glucose metabolism, which is indicative of initial insulin resistance. Thus, citrate consumption could be a previously unknown causative agent for the complications associated with obesity.

  8. Acute phosphate nephropathy.

    PubMed

    Monfared, Ali; Habibzadeh, Seyed Mahmoud; Mesbah, Seyed Alireza

    2014-05-01

    We present acute phosphate nephropathy in a 28-year-old man, which was developed after a car accident due to rhabdomyolysis. Treatment of acute kidney injury was done with administration of sodium bicarbonate.

  9. Metal-phosphate binders

    DOEpatents

    Howe, Beth Ann [Lewistown, IL; Chaps-Cabrera, Jesus Guadalupe [Coahuila, MX

    2009-05-12

    A metal-phosphate binder is provided. The binder may include an aqueous phosphoric acid solution, a metal-cation donor including a metal other than aluminum, an aluminum-cation donor, and a non-carbohydrate electron donor.

  10. Effects of oral administration of sodium citrate or acetate to pigs on blood parameters, postmortem glycolysis, muscle pH decline, and quality attributes of pork.

    PubMed

    Stephens, J W; Dikeman, M E; Unruh, J A; Haub, M D; Tokach, M D; Dritz, S S

    2008-07-01

    The objective of this study was to determine the effects of oral administration of sodium citrate (CIT) or acetate (ACE) to pigs on blood parameters, postmortem glycolysis, pH decline, and quality attributes of pork. Previous studies have shown that CIT has the potential to inhibit phosphofructokinase (PFK), a key enzyme in postmortem muscle glycolysis. In Exp. 1, CIT, ACE, or water was orally administered (0.75 g/kg of BW) to 24 pigs. After a 30-min rest, pigs were exercised, and blood samples were taken at 45 and 75 min after oral treatment. Citrate and ACE tended (P = 0.08) to increase blood pH and increased (P = 0.02) bicarbonate levels immediately after exercise. After a 30-min rest, blood pH of pigs administered ACE tended (P = 0.09) to remain higher, whereas blood pH of CIT-treated pigs was similar to that of control pigs. Bicarbonate levels in ACE- and CIT-treated pigs were still greater (P < 0.05) than those of control pigs at 75 min after oral treatment. In Exp. 2, 30 pigs were administered CIT, ACE, or water 45 min before stunning (electric plus captive bolt). Antemortem treatments had no effect (P > 0.10) on muscle pH or postmortem concentrations of the glycolytic metabolites of glucose-6 phosphate, fructose-6 phosphate, fructose-1,6 bisphosphate, glyceraldehyde-3 phosphate, dihydroxyacetone phosphate, or lactate. Minor, but inconsistent, differences in quality attributes were found in LM chops, and no differences in quality attributes were found between control and CIT- or ACE-treated pigs for inside and outside semimembranosus muscles (P > 0.10). There was no significant inhibition of the PFK enzyme by orally administered CIT or ACE; however, the PFK glycolytic metabolite data analysis indicated that PFK was a main regulatory enzyme in postmortem muscle.

  11. Phosphate control in dialysis

    PubMed Central

    Cupisti, Adamasco; Gallieni, Maurizio; Rizzo, Maria Antonietta; Caria, Stefania; Meola, Mario; Bolasco, Piergiorgio

    2013-01-01

    Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease–mineral and bone disorder (CKD–MBD) management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive–convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P) mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200–300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source. Finally, boiling should be the preferred cooking procedure, because it induces food demineralization, including phosphate loss. The integrated approach outlined in this article should be actively adapted as a therapeutic alliance by clinicians, dieticians, and patients for an effective control of phosphate balance in dialysis patients. PMID:24133374

  12. Phosphate control in dialysis.

    PubMed

    Cupisti, Adamasco; Gallieni, Maurizio; Rizzo, Maria Antonietta; Caria, Stefania; Meola, Mario; Bolasco, Piergiorgio

    2013-10-04

    Prevention and correction of hyperphosphatemia is a major goal of chronic kidney disease-mineral and bone disorder (CKD-MBD) management, achievable through avoidance of a positive phosphate balance. To this aim, optimal dialysis removal, careful use of phosphate binders, and dietary phosphate control are needed to optimize the control of phosphate balance in well-nourished patients on a standard three-times-a-week hemodialysis schedule. Using a mixed diffusive-convective hemodialysis tecniques, and increasing the number and/or the duration of dialysis tecniques are all measures able to enhance phosphorus (P) mass removal through dialysis. However, dialytic removal does not equal the high P intake linked to the high dietary protein requirement of dialysis patients; hence, the use of intestinal P binders is mandatory to reduce P net intestinal absorption. Unfortunately, even a large dose of P binders is able to bind approximately 200-300 mg of P on a daily basis, so it is evident that their efficacy is limited in the case of an uncontrolled dietary P load. Hence, limitation of dietary P intake is needed to reach the goal of neutral phosphate balance in dialysis, coupled to an adequate protein intake. To this aim, patients should be informed and educated to avoid foods that are naturally rich in phosphate and also processed food with P-containing preservatives. In addition, patients should preferentially choose food with a low P-to-protein ratio. For example, patients could choose egg white or protein from a vegetable source. Finally, boiling should be the preferred cooking procedure, because it induces food demineralization, including phosphate loss. The integrated approach outlined in this article should be actively adapted as a therapeutic alliance by clinicians, dieticians, and patients for an effective control of phosphate balance in dialysis patients.

  13. Hydrous iron oxide modified diatomite as an active filtration medium for phosphate capture.

    PubMed

    Wang, Zhe; Lin, Yan; Wu, Deyi; Kong, Hainan

    2016-02-01

    A simple method to functionalize diatomite with hydrous iron oxide was attempted and its performance as a new active filtration material to remove and recover phosphate from water was investigated under varying solution conditions. The Langmuir phosphate adsorption capacity increased from 0.6 mgP/g for raw diatomite to 4.89, 14.71, 25.02 mgP/g for hydrous iron oxide modified diatomite (HIOMD), depending on the amount of iron loaded. Loading of hydrous iron oxide caused the increase in true and bulk density and a decline in filtration rate, but to a lesser extent. It was shown that the HIOMD product with suitable iron content could retain a good filtration performance with a greatly increased adsorption capacity for phosphate. The phosphate adsorption increased by decreasing pH and by increasing ionic strength at high pH levels. The adsorption process was interpreted by ligand exchange. Coexisting oxyanions of sulfate, nitrate, citrate, carbonate, silicate and humic acid showed different effects on phosphate fixation but it was presumed that their influence at their concentrations and pH levels commonly encountered in effluent or natural waters was limited, i.e., HIOMD had a reasonably good selectivity. Results in repeated adsorption, desorption and regeneration experiment showed that the adsorbed phosphate could be recovered and the material could be reused after regeneration. The column test showed that HIOMD could be potentially utilized as an adsorption filtration medium for phosphate removal and recovery from water.

  14. Maltose phosphorylase from Lactobacillus brevis: purification, characterization, and application in a biosensor for ortho-phosphate.

    PubMed

    Hüwel, S; Haalck, L; Conrath, N; Spener, F

    1997-11-01

    With the goal to obtain maltose phosphorylase as a tool to determine ortho-phosphate, the enzyme from Lactobacillus brevis was purified to 98% by an expeditious FPLC-aided procedure which included anion exchange chromatography, gel filtration, and hydroxyapatite chromatography. The native maltose phosphorylase had a molecular mass of 196 kDa and consisted of two 88 kDa subunits. In isoelectric focusing two isoforms with pI values of 4.2 and 4.6 were observed. Maximum enzyme activity was obtained at 36 degrees C and pH 6.5 and was independent of pyridoxal 5'-phosphate. The apparent K(m) values with maltose and phosphate as substrates were 0.9 mmol l-1 and 1.8 mmol l-1, respectively. Maltose phosphorylase could be stored in 10 mM phosphate buffer pH 6.5 at 4 degrees C with a loss of activity of only 7% up to 6 months. The stability of the enzyme at high temperatures was enhanced significantly using additives like phosphate, citrate, and imidazole. The purified maltose phosphorylase was used as key enzyme in a phosphate sensor consisting of maltose phosphorylase and glucose oxidase. A detection limit of 0.1 microM phosphate was observed and the sensor response was linear in the range between 0.5 and 10 microM.

  15. 3-Bromopyruvate antagonizes effects of lactate and pyruvate, synergizes with citrate and exerts novel anti-glioma effects.

    PubMed

    El Sayed, S M; El-Magd, R M Abou; Shishido, Y; Chung, S P; Diem, T H; Sakai, T; Watanabe, H; Kagami, S; Fukui, K

    2012-02-01

    Oxidative stress-energy depletion therapy using oxidative stress induced by D-amino acid oxidase (DAO) and energy depletion induced by 3-bromopyruvate (3BP) was reported recently (El Sayed et al., Cancer Gene Ther., 19, 1-18, 2012). Even in the presence of oxygen, cancer cells oxidize glucose preferentially to produce lactate (Warburg effect) which seems vital for cancer microenvironment and progression. 3BP is a closely related structure to lactate and pyruvate and may antagonize their effects as a novel mechanism of its action. Pyruvate exerted a potent H(2)O(2) scavenging effect to exogenous H(2)O(2), while lactate had no scavenging effect. 3BP induced H(2)O(2) production. Pyruvate protected against H(2)O(2)-induced C6 glioma cell death, 3BP-induced C6 glioma cell death but not against DAO/D-serine-induced cell death, while lactate had no protecting effect. Lactate and pyruvate protected against 3BP-induced C6 glioma cell death and energy depletion which were overcome with higher doses of 3BP. Lactate and pyruvate enhanced migratory power of C6 glioma which was blocked by 3BP. Pyruvate and lactate did not protect against C6 glioma cell death induced by other glycolytic inhibitors e.g. citrate (inhibitor of phosphofructokinase) and sodium fluoride (inhibitor of enolase). Serial doses of 3BP were synergistic with citrate in decreasing viability of C6 glioma cells and spheroids. Glycolysis subjected to double inhibition using 3BP with citrate depleted ATP, clonogenic power and migratory power of C6 glioma cells. 3BP induced a caspase-dependent cell death in C6 glioma. 3BP was powerful in decreasing viability of human glioblastoma multiforme cells (U373MG) and C6 glioma in a dose- and time-dependent manner.

  16. SbnG, a citrate synthase in Staphylococcus aureus: a new fold on an old enzyme.

    PubMed

    Kobylarz, Marek J; Grigg, Jason C; Sheldon, Jessica R; Heinrichs, David E; Murphy, Michael E P

    2014-12-05

    In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. We present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic gene clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. A structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production.

  17. Rock phosphate enriched compost: an approach to improve low-grade Indian rock phosphate.

    PubMed

    Biswas, D R; Narayanasamy, G

    2006-12-01

    In this study, rock phosphate enriched composts (RP-compost) were prepared by mixing four low-grade Indian rock phosphates with rice straw with and without Aspergillus awamori. RP-compost had higher total P, citrate soluble P (CSP), organic P (Org.P), acid and alkaline phosphatase activities, and lower water soluble P (WSP) and microbial biomass C (MBC) than normal compost. Inoculation with A. awamori increased total P, WSP, CSP, Org.P, MBC and acid phosphatase activity. RP-compost recorded lower Olsen P at the initial period of incubation study than diammonium phosphate (DAP), but improved significantly with the progress of time. RP-compost prepared at 4% charged rate resulted in higher Olsen P throughout the incubation period compared to 2% charged rate. Similar trend were obtained with those RP-composts prepared with A. awamori. Data on pot experiment revealed higher yield and P uptake by mungbean (Vigna radiata) due to addition of RP-composts over control. The effectiveness of RP-compost ranged from 61.4% (MussoorieRP-compost) to 94.1% (PuruliaRP-compost) as that of DAP on dry matter yield and 48.8% (JhabuaRP-compost) to 83.7% (PuruliaRP-compost) on total P uptake. Enriched compost prepared at 4% charged rate recorded 15.8% and 10.6% extra yield and P uptake, respectively by mungbean over 2% charged compost. Also RP-compost inoculated with A. awamori resulted in 13.0 and 21.5% extra yield and P uptake than without A. awamori treated group. Thus, RP enriched compost could be an alternative and viable technology to utilize both low-grade RPs and rice straw efficiently.

  18. A turn-on fluorescent indicator for citrate with micromolar sensitivity.

    PubMed

    Burguete, M Isabel; Galindo, Francisco; Luis, Santiago V; Vigara, Laura

    2007-09-28

    A turn-on fluorescent indicator for citric acid (citrate) has been developed, displaying high emission enhancement (+1500%) and low interference by other carboxylates. The sensor is based on the non-emissive copper(II) complex of a fluorescent amino amide, which, upon addition of citrate decomplexates to yield the emissive ligand. The detection limit estimated for this new chemosensing system is about 0.5 microM. This novel approach to the analysis of citrate constitutes an alternative ca. 10(2)-10(3) times more sensitive than the standard method based on the enzyme citrate lyase.

  19. Engineering genetically encoded nanosensors for real-time in vivo measurements of citrate concentrations.

    PubMed

    Ewald, Jennifer C; Reich, Sabrina; Baumann, Stephan; Frommer, Wolf B; Zamboni, Nicola

    2011-01-01

    Citrate is an intermediate in catabolic as well as biosynthetic pathways and is an important regulatory molecule in the control of glycolysis and lipid metabolism. Mass spectrometric and NMR based metabolomics allow measuring citrate concentrations, but only with limited spatial and temporal resolution. Methods are so far lacking to monitor citrate levels in real-time in-vivo. Here, we present a series of genetically encoded citrate sensors based on Förster resonance energy transfer (FRET). We screened databases for citrate-binding proteins and tested three candidates in vitro. The citrate binding domain of the Klebsiella pneumoniae histidine sensor kinase CitA, inserted between the FRET pair Venus/CFP, yielded a sensor highly specific for citrate. We optimized the peptide linkers to achieve maximal FRET change upon citrate binding. By modifying residues in the citrate binding pocket, we were able to construct seven sensors with different affinities spanning a concentration range of three orders of magnitude without losing specificity. In a first in vivo application we show that E. coli maintains the capacity to take up glucose or acetate within seconds even after long-term starvation.

  20. Transport of citrate-coated silver nanoparticles in unsaturated sand

    NASA Astrophysics Data System (ADS)

    Kumahor, Samuel; Hron, Pavel; Metreveli, George; Schaumann, Gabriele; Vogel, Hans-Jörg

    2015-04-01

    Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Unlike for saturated transport, studies on unsaturated transport as typical for soil are currently scarce. We investigated the mobility of citrate-coated Ag NPs in unsaturated sand (grain diameter: 0.1-0.3 mm). For three flux rates and a given pore-water ionic strength (1 mM KNO3), the citrate-coated Ag NPs were less mobile at pH = 5 compared to pH = 9. The classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggests unfavorable deposition conditions at both, the air-water interface and solid-water interface. Breakthrough curves measured under quasi-steady state unsaturated flow showed retardation of the citrate-coated Ag NPs compared to inert solute (KBr). After flushing with nanoparticle-free 1 mM KNO3 solution (pH-adjusted), retention was much lower in deeper depths compared to the surface where the particles entered the flow field. The results show a non-linear dependence of nanoparticle (NP) mobility on flux rate and water content. Especially the observed retardation similar to equilibrium sorption is in contrast to observations under saturated flow conditions. A convection-dispersion and reaction model that combines a reversible equilibrium process and a non-equilibrium interaction process reproduced the measured breakthrough curves reasonably well. From comparison between saturated and unsaturated experiments we conclude that the air-water interface is responsible for the reversible equilibrium process while the water-solid interface accounts for irreversible soption.

  1. Analytical chemistry of the citrate process for flue gas desulfurization

    SciTech Connect

    Marchant, W.N.; May, S.L.; Simpson, W.W.; Winter, J.K.; Beard, H.R.

    1980-01-01

    The citrate process for flue gas desulfurization (FGD) is a product of continuing research by the US Bureau of Mines to meet the goal of minimizing the objectionable effects of minerals industry operations upon the environment. The reduction of SO/sub 2/ in solution by H/sub 2/S to produce elemental sulfur by the citrate process is extremely complex and results in solutions that contain at least nine different sulfur species. Process solution analysis is essential to a clear understanding of process chemistry and its safe, efficient operation. The various chemical species, the approximate ranges of their concentrations in citrate process solutions, and the analytical methods evolved to determine them are hydrogen sulfide (approx. 0M to 0.06M) by specific ion electrode, polysulfides (unknown) by ultraviolet (uv) spectrophotometry, elemental sulfur (approx. 0M to approx. 0.001M dissolved, approx. 0M to approx. 0.1M suspended) by uv spectrophotometry, thiosulfate (approx. 0M to approx. 0.25M) by iodometry or high performance liquid chromatography (HPLC), polythionates (approx. 0M to approx. 0.01M) by thin layer chromatography (TLC), dithionite (searched for but not detected in process solutions) by polarography or TLC, bisulfite (approx. 0M to 0.2M) by iodometry, sulfate (approx. 0M to 1M) by a Bureau-developed gravimetric procedure, citric acid (approx. 0M to 0.5M) by titration or visible colorimetry, glycolic acid (approx. 0M to 1M) by HPLC, sodium (approx. 1.5M) by flame photometry, and chloride by argentometric titration.

  2. Determination of sildenafil citrate and its main metabolite by sample stacking with polarity switching using micellar electrokinetic chromatography.

    PubMed

    Berzas Nevado, J J; Flores, J Rodriguez; Peñalvo, G Castañeda; Rodríguez, Fariñas N

    2002-04-12

    Micellar electrokinetic capillary chromatography (MEKC) coupled with sample stacking and polarity switching was investigated for the determination of Viagra (sildenafil citrate, SC) and its metabolite (UK-103,320, UK) in human serum in the concentration range of clinical interest. Human serum samples spiked with SC and UK were eluted with methanol from a C18 cartridge, the extract was evaporated and regenerated in a solution that contained 1 mM phosphate buffer (pH 12.3) and 20% methanol. The MEKC separation was performed using an injection time of 275 s, a polarity switching time of 93 s, a phosphate buffer, (pH 12.3, 15 mM) containing 25 mM sodium dodecyl sulfate as separation electrolyte and a fused-silica capillary. The analysis takes about 6 min and gives satisfactory inter-day precision with respect to migration times and linear responses over the 80-900 ng/ml concentration range investigated for SC and UK. Intra-day RSDs (n=4 graphs) for the slopes of the calibration graphs were 4.86% for SC and 3.50% for UK. Inter-day RSDs for the slopes were 4.37% for SC and 5.39% for UK. Detection limits (S/N=3) were about 17 ng/ml for both compounds in human serum. A 1-ml volume of blood serum was necessary to do this determination.

  3. Antitumor effect and toxicity of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles in mice bearing breast cancer

    PubMed Central

    2013-01-01

    Background Magnetic fluids containing superparamagnetic iron oxide nanoparticles represent an attractive platform as nanocarriers in chemotherapy. Recently, we developed a formulation of maghemite nanoparticles coated with rhodium (II) citrate, which resulted in in vitro cytotoxicity enhanced up to 4.6 times when compared to free rhodium (II) citrate formulation on breast carcinoma cells. In this work, we evaluate the antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Methods Mice were evaluated with regard to the treatments’ toxicity through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine; DNA fragmentation and cell cycle of bone marrow cells; and liver, kidney and lung histology. In addition, the antitumor activity of rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate was verified by tumor volume reduction, histology and immunohistochemistry. Results Regarding the treatments’ toxicity, no experimental groups had alterations in levels of serum ALT or creatinine, and this suggestion was corroborated by the histopathologic examination of liver and kidney of mice. Moreover, DNA fragmentation frequency of bone marrow cells was lower than 15% in all experimental groups. On the other hand, the complexes rhodium (II) citrate-functionalized maghemite and free rhodium (II) citrate led to a marked growth inhibition of tumor and decrease in CD31 and Ki-67 staining. Conclusions In summary, we demonstrated that both rhodium (II) citrate and maghemite nanoparticles coated with rhodium (II) citrate formulations exhibited antitumor effects against 4T1 metastatic breast cancer cell line following intratumoral administration. This antitumor effect was followed by inhibition of both cell proliferation and microvascularization and by tumor tissue injury characterized as necrosis and fibrosis. Remarkably, this is the first published report

  4. Methodology of citrate-based biomaterial development and application

    NASA Astrophysics Data System (ADS)

    Tran, M. Richard

    Biomaterials play central roles in modern strategies of regenerative medicine and tissue engineering. Attempts to find tissue-engineered solutions to cure various injuries or diseases have led to an enormous increase in the number of polymeric biomaterials over the past decade. The breadth of new materials arises from the multiplicity of anatomical locations, cell types, and mode of application, which all place application-specific requirements on the biomaterial. Unfortunately, many of the currently available biodegradable polymers are limited in their versatility to meet the wide range of requirements for tissue engineering. Therefore, a methodology of biomaterial development, which is able to address a broad spectrum of requirements, would be beneficial to the biomaterial field. This work presents a methodology of citrate-based biomaterial design and application to meet the multifaceted needs of tissue engineering. We hypothesize that (1) citric acid, a non-toxic metabolic product of the body (Krebs Cycle), can be exploited as a universal multifunctional monomer and reacted with various diols to produce a new class of soft biodegradable elastomers with the flexibility to tune the material properties of the resulting material to meet a wide range of requirements; (2) the newly developed citrate-based polymers can be used as platform biomaterials for the design of novel tissue engineering scaffolding; and (3) microengineering approaches in the form thin scaffold sheets, microchannels, and a new porogen design can be used to generate complex cell-cell and cell-microenvironment interactions to mimic tissue complexity and architecture. To test these hypotheses, we first developed a methodology of citrate-based biomaterial development through the synthesis and characterization of a family of in situ crosslinkable and urethane-doped elastomers, which are synthesized using simple, cost-effective strategies and offer a variety methods to tailor the material properties to

  5. Improved Manganese Phosphate Coatings

    DTIC Science & Technology

    1975-04-01

    Conversion coatings 3 . Phosphating bath 20 AGrjC onln odd*. ta It .. c..soMV midP 1J.,alft. by block noc.mb) Work was conducted to determine the mechanism by...34 TABULAR DATA Table I Analyses of Solution and Coating for Phosphating Baths 4 of Di-ferlng Compositions 11 Atomic Absorption...manganese and iron phosphate coating: k * a. Mn(H 2PO4) 2 Nn-P0 4 + H3PO0 k2 k) b. 3MnHPO4 - Mn3 (P04) 2 + H3i’O4 k4 k5 c. Fe(H 2PO4) 2 -01 FeHPO4

  6. Phosphate Mines, Jordan

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Jordan's leading industry and export commodities are phosphate and potash, ranked in the top three in the world. These are used to make fertilizer. The Jordan Phosphate Mines Company is the sole producer, having started operations in 1935. In addition to mining activities, the company produces phosphoric acid (for fertilizers, detergents, pharmaceuticals), diammonium phosphate (for fertilizer), sulphuric acid (many uses), and aluminum fluoride (a catalyst to make aluminum and magnesium).

    The image covers an area of 27.5 x 49.4 km, was acquired on September 17, 2005, and is located near 30.8 degrees north latitude, 36.1 degrees east longitude.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

  7. Synoviorthesis with erbium-169: a double-blind controlled comparison of erbium-169 with corticosteroid.

    PubMed Central

    Gumpel, J M; Matthews, S A; Fisher, M

    1979-01-01

    Intra-articular injections of erbium--169 citrate and methylprednisolone acetate in hand joints were compared in a randomly selected double-blind trial. The patients included 21 with rheumatoid arthritis and 3 with psoriatic arthritis, and the design was an intrapatient comparison. No difference between joints treated with the radioisotope or steroid was observed in the year following injection. PMID:386961

  8. Comparison of magnesium status using X-ray dispersion analysis following magnesium oxide and magnesium citrate treatment of healthy subjects.

    PubMed

    Shechter, Michael; Saad, Tomer; Shechter, Alon; Koren-Morag, Nira; Silver, Burton B; Matetzky, Shlomi

    2012-03-01

    The magnesium content in food consumed in the Western world is steadily decreasing. Hypomagnesemia is associated with increased incidence of diabetes mellitus, metabolic syndrome, all-cause and coronary artery disease mortality. We investigated the impact of supplemental oral magnesium citrate versus magnesium oxide on intracellular magnesium levels ([Mg2+]i) and platelet function in healthy subjects with no apparent heart disease. In a randomized, prospective, double-blind, crossover study, 41 (20 women) healthy volunteers [mean age 53±8 (range 31-75) years] received either magnesium oxide monohydrate tablets (520 mg/day of elemental magnesium) or magnesium citrate tablets (295.8 mg/day of elemental magnesium) for one month (phase 1), followed by a four-week wash-out period, and then crossover treatment for one month (phase 2). [Mg2+]i was assessed from sublingual cells through x-ray dispersion (normal values 37.9±4.0 mEq/L), serum magnesium levels, platelet aggregation, and quality-of-life questionnaires were assessed before and after each phase. Oral magnesium oxide, rather than magnesium citrate, significantly increased [Mg2+]i (34.4±3 versus 36.3±2 mEq/L, p<0.001 and 34.7±2 versus 35.4±2 mEq/L, p=0.097; respectively), reduced total cholesterol (201±37 versus 186±27 mg/dL, p=0.016 and 187±28 versus 187±25 mg/dL, p=0.978; respectively) and low-density lipoprotein (LDL) cholesterol (128±22 versus 120±25 mg/dL, p=0.042 and 120±23 versus 121±22 mg/dL, p=0.622; respectively). Noteworthy is that both treatments significantly reduced epinephrine-induced platelet aggregation (78.9±16% versus 71.7±23%, p=0.013 and 81.3±15% versus 73.3±23%, p=0.036; respectively). Thus, oral magnesium oxide treatment significantly improved [Mg2+]i, total and LDL cholesterol compared with magnesium citrate, while both treatments similarly inhibited platelet aggregation in healthy subjects with no apparent heart disease.

  9. Molecular mechanisms of crystallization impacting calcium phosphate cements

    PubMed Central

    Giocondi, Jennifer L.; El-Dasher, Bassem S.; Nancollas, George H.; Orme, Christine A.

    2010-01-01

    The biomineral calcium hydrogen phosphate dihydrate (CaHPO4·2H2O), known as brushite, is a malleable material that both grows and dissolves faster than most other calcium minerals, including other calcium phosphate phases, calcium carbonates and calcium oxalates. Within the body, this ready formation and dissolution can play a role in certain diseases, such as kidney stone and plaque formation. However, these same properties, along with brushite’s excellent biocompatibility, can be used to great benefit in making resorbable biomedical cements. To optimize cements, additives are commonly used to control crystallization kinetics and phase transformation. This paper describes the use of in situ scanning probe microscopy to investigate the role of several solution parameters and additives in brushite atomic step motion. Surprisingly, this work demonstrates that the activation barrier for phosphate (rather than calcium) incorporation limits growth kinetics and that additives such as magnesium, citrate and bisphosphonates each influence step motion in distinctly different ways. Our findings provide details of how, and where, molecules inhibit or accelerate kinetics. These insights have the potential to aid in designing molecules to target specific steps and to guide synergistic combinations of additives. PMID:20308110

  10. Inkjet printing of silver citrate conductive ink on PET substrate

    NASA Astrophysics Data System (ADS)

    Nie, Xiaolei; Wang, Hong; Zou, Jing

    2012-11-01

    Direct synthesis of silver conductive film on PET substrate by inkjet printing silver citrate conductive ink was presented in this paper. This kind of conductive ink contained silver citrate as silver precursor, 1,2-diaminopropane as complex agent dissolving the silver salt and methanol and isopropanol as a media adjusting the viscosity and surface tension. The formation of silver-amine complex reduced the decomposition temperature from 180 °C to 135 °C, thus the ink could be cured at relatively low temperature. The film reached the lowest resistivity of 17 μΩ cm after cured at 150 °C for 50 min, 3.1 μΩ cm at 230 °C and possessed high reflection and excellent adhesive property. Electrical conductivity, surface morphology and composition were investigated by four-point probe method, scanning electron microscope (SEM) and energy dispersive X-ray spectroscopy (EDS). It is demonstrated how the cured condition affects the silver film. Moreover, radio-frequency identification (RFID) antenna was fabricated by inkjet printing, which opens up routes for the flexible electronics fabrication.

  11. Why sildenafil and sildenafil citrate monohydrate crystals are not stable?

    PubMed

    Sawatdee, Somchai; Pakawatchai, Chaveng; Nitichai, Kwanjai; Srichana, Teerapol; Phetmung, Hirihattaya

    2015-10-01

    Sildenafil citrate was crystallized by various techniques aiming to determine the behavior and factors affecting the crystal growth. There are only 2 types of sildenafil obtaining from crystallization: sildenafil (1) and sildenafil citrate monohydrate (2). The used techniques were (i) crystallization from saturated solutions, (ii) addition of an antisolvent, (iii) reflux and (iv) slow solvent evaporation method. By pursuing these various methods, our work pointed that the best formation of crystal (1) was obtained from technique no. (i). Surprisingly, the obtained crystals (1) were perfected if the process was an acidic pH at a cold temperature then perfect crystals occurred within a day. Crystals of compound (2) grew easily using technique no. (ii) which are various polar solvents over a wide range of pH and temperature preparation processes. The infrared spectroscopy and nuclear magnetic resonance spectra fit well with these two X-ray crystal structures. The crystal structures of sildenafil free base and salt forms were different from their different growing conditions leading to stability difference.

  12. ATP citrate lyase inhibitors as novel cancer therapeutic agents.

    PubMed

    Zu, Xu-Yu; Zhang, Qing-Hai; Liu, Jiang-Hua; Cao, Ren-Xian; Zhong, Jing; Yi, Guang-Hui; Quan, Zhi-Hua; Pizzorno, Giuseppe

    2012-05-01

    ATP citrate lyase (ACL or ACLY) is an extra-mitochondrial enzyme widely distributed in various human and animal tissues. ACL links glucose and lipid metabolism by catalyzing the formation of acetyl-CoA and oxaloacetate from citrate produced by glycolysis in the presence of ATP and CoA. ACL is aberrantly expressed in many immortalized cells and tumors, such as breast, liver, colon, lung and prostate cancers, and is correlated reversely with tumor stage and differentiation, serving as a negative prognostic marker. ACL is an upstream enzyme of the long chain fatty acid synthesis, providing acetyl-CoA as an essential component of the fatty acid synthesis. Therefore, ACL is a key enzyme of cellular lipogenesis and potent target for cancer therapy. As a hypolipidemic strategy of metabolic syndrome and cancer treatment, many small chemicals targeting ACL have been designed and developed. This review article provides an update for the research and development of ACL inhibitors with a focus on their patent status, offering a new insight into their potential application.

  13. Formulation, Characterization and Physicochemical Evaluation of Potassium Citrate Effervescent Tablets

    PubMed Central

    Aslani, Abolfazl; Fattahi, Fatemeh

    2013-01-01

    Purpose: The aim of this study was to design and formulation of potassium citrate effervescent tablet for reduction of calcium oxalate and urate kidney stones in patients suffering from kidney stones. Methods: In this study, 13 formulations were prepared from potassium citrate and effervescent base in different concentration. The flowability of powders and granules was studied. Then effervescent tablets were prepared by direct compression, fusion and wet granulation methods. The prepared tablets were evaluated for hardness, friability, effervescent time, pH, content uniformity. To amend taste of formulations, different flavoring agents were used and then panel test was done by using Latin Square method by 30 volunteers. Results: Formulations obtained from direct compression and fusion methods had good flow but low hardness. Wet granulation improves flowability and other physicochemical properties such as acceptable hardness, effervescence time ≤3 minutes, pH<6, friability < 1%, water percentage < 0.5% and accurate content uniformity. In panel test, both of combination flavors; (orange - lemon) and (strawberry - raspberry) had good acceptability. Conclusion: The prepared tablets by wet granulation method using PVP solution had more tablet hardness. It is a reproducible process and suitable to produce granules that are compressed into effervescent tablets due to larger agglomerates. PMID:24312839

  14. Transcriptional regulation of Bacillus subtilis citrate synthase genes.

    PubMed

    Jin, S; Sonenshein, A L

    1994-08-01

    The Bacillus subtilis citrate synthase genes citA and citZ were repressed during early exponential growth phase in nutrient broth medium and were induced as cells reached the end of exponential phase. Both genes were also induced by treatment of cells with the drug decoyinine. After induction, the steady-state level of citZ mRNA was about five times higher than that of citA mRNA. At least some of the citZ transcripts read through into the isocitrate dehydrogenase (citC) gene. Transcription from an apparent promoter site located near the 3' end of the citZ gene also contributed to expression of citC. In minimal medium, citA transcription was about 6-fold lower when glucose was the sole carbon source than it was when succinate was the carbon source. Expression of the citZ gene was repressed 2-fold by glucose and 10-fold when glucose and glutamate were present simultaneously. This latter synergistic repression is similar to the effect of glucose and glutamate on steady-state citrate synthase enzyme activity. CitR, a protein of the LysR family, appeared to be a repressor of citA but not of citZ.

  15. Why sildenafil and sildenafil citrate monohydrate crystals are not stable?

    PubMed Central

    Sawatdee, Somchai; Pakawatchai, Chaveng; Nitichai, Kwanjai; Srichana, Teerapol; Phetmung, Hirihattaya

    2015-01-01

    Sildenafil citrate was crystallized by various techniques aiming to determine the behavior and factors affecting the crystal growth. There are only 2 types of sildenafil obtaining from crystallization: sildenafil (1) and sildenafil citrate monohydrate (2). The used techniques were (i) crystallization from saturated solutions, (ii) addition of an antisolvent, (iii) reflux and (iv) slow solvent evaporation method. By pursuing these various methods, our work pointed that the best formation of crystal (1) was obtained from technique no. (i). Surprisingly, the obtained crystals (1) were perfected if the process was an acidic pH at a cold temperature then perfect crystals occurred within a day. Crystals of compound (2) grew easily using technique no. (ii) which are various polar solvents over a wide range of pH and temperature preparation processes. The infrared spectroscopy and nuclear magnetic resonance spectra fit well with these two X-ray crystal structures. The crystal structures of sildenafil free base and salt forms were different from their different growing conditions leading to stability difference. PMID:26594116

  16. Green synthesis of multi metal- citrate complexes and their characterization

    NASA Astrophysics Data System (ADS)

    Raju, Usha; Warkar, Sudhir G.; Kumar, Anil

    2017-04-01

    Four new multi metal-citrate complexes have been synthesized through green synthetic pathways. Their synthesis by hydrothermal route in the present research is decorated with features such as, a simple one pot synthesis, cost effectiveness, easy to scale up for commercial production, efficient synthesis conditions like mild temperature and shorter duration which further rules out the possibility of forming byproducts which may cause damage to the environment and being environmental benign as it eliminates the use and recovery of harmful organic solvents such as N, N- dimethyl formamide and N, N- diethyl formamide, used by the researchers in the past during the synthesis of similar metal- organic framework complexes. All four complexes are well defined crystalline materials with polynuclear multi metal-citrate framework having cubic crystal structure as indicated by their Powder X-ray Diffraction patterns. These complexes have been characterized by Fourier Transform Infrared Spectroscopy, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Thermogravimetric analysis and Powder XRD techniques.

  17. Photodegradation of uranium-citrate complex with uranium recovery

    SciTech Connect

    Dodge, C.J.; Francis, A.J. )

    1994-07-01

    Upon exposure to visible light, uranyl citrate complex showed photodegradation of citric acid to acetic acid and carbon dioxide, with the precipitation of uranium as uranium trioxide (UO[sub 3][center dot]2H[sub 2]O). The initial pH and presence of oxygen affected the rate and extent of photochemical degradation of the complex, the formation of intermediate organic degradation products, and uranium speciation. Under aerobic conditions at pH 3.5, acetic, acetoacetic, 3-oxoglutaric, and malonic acids and acetone were detected; at pH 6.0, 3-oxoglutaric and acetic acids were present. The uranyl U(VI) ion was reduced to uranous U(IV) ion and was subsequently reoxidized to the hexavalent form and precipitated out of solution as uranium trioxide. Uranium trioxide precipitate was insoluble at near-neutral pH and was soluble in acidic pH (<4.1). Under anaerobic conditions, the uranyl citrate complex showed only partial (57%) degradation, and uranium was present in the reduced form as U(IV). Excess citric acid retarded the precipitation of uranium. 26 refs., 9 figs., 1 tab.

  18. Citrate and the conversion of carbohydrate in fat. The activities of citrate-cleavage enzyme and acetate thiokinase in livers of starved and re-fed rats

    PubMed Central

    Kornacker, Melodee S.; Lowenstein, J. M.

    1965-01-01

    1. The activity of citrate-cleavage enzyme varies in accordance with the nutritional state of the animal. It is suppressed on starvation and restored on re-feeding after starvation. 2. The increase in enzyme activity that occurs on re-feeding starved animals depends on the diet. It is largest on diets high in carbohydrate and low in fat, and smallest on diets high in fat. Intermediate increases are obtained with balanced diets. 3. The ratio of activities of citrate-cleavage enzyme to acetate thiokinase varies from 2·5 for animals maintained on a balanced diet to 20 for animals re-fed with a diet high in carbohydrate. 4. The changes in activity of citrate-cleavage enzyme correlate with changes in the rate of fatty acid synthesis and provide evidence for the involvement of the citrate-cleavage reaction in fatty acid synthesis. PMID:14342232

  19. Inactivation of Bakers' yeast glucose-6-phosphate dehydrogenase by aluminum

    SciTech Connect

    Cho, Sungwoo; Joshi, J.G. )

    1989-04-18

    Preincubation of yeast glucose-6-phosphate dehydrogenase (G6PD) with Al(III) produced an inactive enzyme containing 1 mol of Al(III)/mol of enzyme subunit. None of the enzyme-bound Al(III) was dissociated by dialysis against 10 mM Tris-HCl, pH 7.0, containing 0.2 mM EDTA at 4{degree}C for 24 h. Citrate, NADP{sup +}, EDTA, or NaF protected the enzyme against the Al(III) inactivation. The Al(III)-inactivated enzyme, however, was completely reactivated only by citrate and NaF. The dissociation constant for the enzyme-aluminum complex was calculated to be 4 {times} 10{sup {minus}6} M with NaF, a known reversible chelator for aluminum. Modification of histidine and lysine residues of the enzyme with diethyl pyrocarbonate and acetylsalicylic acid, respectively, inactivated the enzyme. However, the modified enzyme still bound 1 mol of Al(III)/mol of enzyme subunit. Circular dichroism studies showed that the binding of Al(III) to the enzyme induced a decrease in {alpha}-helix and {beta}-sheet and an increase in random coil. Therefore, it is suggested that inactivation of G6PD by Al(III) is due to the conformational change induced by Al(III) binding.

  20. Domestic phosphate deposits

    USGS Publications Warehouse

    McKelvey, V.E.; Cathcart, J.B.; Altschuler, Z.S.; Swanson, R.W.; Lutz, Katherine

    1953-01-01

    Most of the worlds phosphate deposits can be grouped into six types: 1) igneous apatite deposits; 2) marine phosphorites; 3) residual phosphorites; 4) river pebble deposits; 5) phosphatized rock; and 6) guano. The igneous apatites and marine phosphorites form deposits measurable in millions or billions of tons; the residual deposits are measurable in thousands or millions; and the other types generally only in thousands of tons. Igneous apatite deposits have been mined on a small scale in New York, New Jersey, and Virginia. Marine phosphorites have been mined in Montana, Idaho, Utah, Wyoming, Arkansas, Tennessee, North Carolina, South Carolina, Georgia, and Florida. Residual phosphorites have been mined in Tennessee, Pennsylvania, and Florida. River pebble has been produced in South Carolina and Florida; phosphatized rock in Tennessee and Florida; and guano in New Mexico and Texas. Present production is limited almost entirely to Florida, Tennessee, Montana, Idaho, and Wyoming. Incomplete but recently partly revised estimates indicate the presence of about 5 billion tons of phosphate deposits in the United States that is minable under present economic conditions. Deposits too lean in quality or thickness to compete with those in the western and southeastern fields probably contain tens of billions of tons.

  1. Glucose-6-phosphate dehydrogenase

    MedlinePlus

    ... Elsevier Saunders; 2012:chap 42. Read More Enzyme Glucose-6-phosphate dehydrogenase deficiency Hemoglobin Review Date 2/11/2016 Updated by: ... A.M. Editorial team. Related MedlinePlus Health Topics G6PD Deficiency Browse the Encyclopedia A.D.A.M., Inc. ...

  2. Photochemical degradation of citrate buffers leads to covalent acetonation of recombinant protein therapeutics

    PubMed Central

    Valliere-Douglass, John F; Connell-Crowley, Lisa; Jensen, Randy; Schnier, Paul D; Trilisky, Egor; Leith, Matt; Follstad, Brian D; Kerr, Jennifer; Lewis, Nathan; Vunnum, Suresh; Treuheit, Michael J; Balland, Alain; Wallace, Alison

    2010-01-01

    Novel acetone and aldimine covalent adducts were identified on the N-termini and lysine side chains of recombinant monoclonal antibodies. Photochemical degradation of citrate buffers, in the presence of trace levels of iron, is demonstrated as the source of these modifications. The link between degradation of citrate and the observed protein modifications was conclusively established by tracking the citrate decomposition products and protein adducts resulting from photochemical degradation of isotope labeled 13C citrate by mass spectrometry. The structure of the acetone modification was determined by nuclear magnetic resonance (NMR) spectroscopy on modified–free glycine and found to correspond to acetone linked to the N-terminus of the amino acid through a methyl carbon. Results from mass spectrometric fragmentation of glycine modified with an acetone adduct derived from 13C labeled citrate indicated that the three central carbons of citrate are incorporated onto protein amines in the presence of iron and light. While citrate is known to stoichiometrically decompose to acetone and CO2 through various intermediates in photochemical systems, it has never been shown to be a causative agent in protein carbonylation. Our results point to a previously unknown source for the generation of reactive carbonyl species. This work also highlights the potential deleterious impact of trace metals on recombinant protein therapeutics formulated in citrate buffers. PMID:20836085

  3. 78 FR 64914 - Citric Acid and Certain Citrate Salts From Canada: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-30

    ... International Trade Administration Citric Acid and Certain Citrate Salts From Canada: Final Results of... of the antidumping duty order on citric acid and certain citrate salts from Canada.\\1\\ The review... period of review (POR) is May 1, 2011, through April 30, 2012. \\1\\ See Citric Acid and Certain...

  4. 78 FR 34648 - Citric Acid and Certain Citrate Salts: Preliminary Results of Countervailing Duty Administrative...

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    2013-06-10

    ... International Trade Administration Citric Acid and Certain Citrate Salts: Preliminary Results of Countervailing... review of the countervailing duty (CVD) order on citric acid and citrate salts from the People's Republic... (202) 482-1503. Scope of the Order The merchandise subject to the order is citric acid and...

  5. 77 FR 6061 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-07

    ... International Trade Administration Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of... administrative review of the antidumping duty order on citric acid and certain citrate salts (citric acid) from... initiation of an administrative review of the antidumping duty order on citric acid from Canada with...

  6. 76 FR 5782 - Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-02-02

    ... International Trade Administration Citric Acid and Certain Citrate Salts From Canada: Preliminary Results of... administrative review of the antidumping duty order on citric acid and certain citrate salts (citric acid) from... citric acid from Canada with respect to JBL Canada covering the period November 20, 2008, through May...

  7. 76 FR 34044 - Citric Acid and Certain Citrate Salts From Canada: Final Results of Antidumping Duty...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ... International Trade Administration Citric Acid and Certain Citrate Salts From Canada: Final Results of... preliminary results of the first administrative review of the antidumping duty order on citric acid and certain citrate salts (citric acid) from Canada. The review covers one manufacturer/exporter of...

  8. Evaluation of Manganese Phosphate Coatings.

    DTIC Science & Technology

    1984-02-01

    84003 _____________ 4 . TTLE and -bitle)5. TYPE OF REPORT & PERIOD COVERED EVALUATION OF MANGANESE PHOSPHATE COATINGS Final 6. PERFORMING ORG. REPORT...rosion resistance of the Endurion phosphate was significantly superior to the 4 . basic manganese phosphate . Endurion phosphate with a Supplementary...OF CONTENTS Page STATEMENT OF THE PROBLEM 1 BACKGROUND 1 APPROACH TO THE PROBLEM 3 RESULTS 4 CONCLUSIONS 7 TABLES I. Falex Wear Life Test Procedure 8

  9. Effectiveness of Sodium Picosulfate/Magnesium Citrate (PICO) for Colonoscopy Preparation

    PubMed Central

    Suh, Wu Seok; Jeong, Jin Sik; Kim, Dong Sik; Kim, Sang Woo; Kwak, Dong Min; Hwang, Jong Seong; Kim, Hyun Jin; Park, Man Woo; Shim, Min Chul; Koo, Ja-Il; Kim, Jae Hwang; Shon, Dae Ho

    2014-01-01

    Purpose Bowel preparation with sodium phosphate was recently prohibited by the U.S. Food and Drug Administration. Polyethylene glycol (PEG) is safe and effective; however, it is difficult to drink. To identify an easy bowel preparation method for colonoscopy, we evaluated three different bowel preparation regimens regarding their efficacy and patient satisfaction. Methods In this randomized, comparative study, 892 patients who visited a secondary referral hospital for a colonoscopy between November 2012 and February 2013 were enrolled. Three regimens were evaluated: three packets of sodium picosulfate/magnesium citrate (PICO, group A), two packets of PICO with 1 L of PEG (PICO + PEG 1 L, group B), and two packets of PICO with 2 L of PEG (PICO + PEG 2 L, group C). A questionnaire survey regarding the patients' preference for the bowel preparation regimen and satisfaction was conducted before the colonoscopies. The quality of bowel cleansing was scored by the colonoscopists who used the Aronchick scoring scale and the Ottawa scale. Results The patients' satisfaction rate regarding the regimens were 72% in group A, 64% in group B, and 45.9% in group C. Nausea and abdominal bloating caused by the regimens were more frequent in group C than in group A or group B (P < 0.01). Group C showed the lowest preference rate compared to the other groups (P < 0.01). Group C showed better right colon cleansing efficacy than group A or group B. Conclusion Group A exhibited a better result than group B or group C in patient satisfaction and preference. In the cleansing quality, no difference was noted between groups A and C. PMID:25360429

  10. A novel citrate selective electrode based on surfactant modified nano-clinoptilolite.

    PubMed

    Hasheminejad, Mahdieh; Nezamzadeh-Ejhieh, Alireza

    2015-04-01

    A citrate-selective sensor was prepared by modification of a PVC membrane with modified nano-clinoptilolite particles by hexadecyltrimethyl ammonium surfactant (SMZ). A Nernstian slope of 29.9 ± 0.2 mV per decade of citrate concentration was obtained over the concentration range of 5.0 × 10(-5)-5.0 × 10(-2) mol L(-1) of citrate. The electrode showed a fast response time (⩽ 10 s) and a detection limit of 1.3 × 10(-5) mol L(-1) of citrate. The linear range and detection limit were respectively changed to 1.0 × 10(-4)-5.0 × 10(-2) mol L(-1) and 1.0 × 10(-4) mol L(-1) of citrate when the micronized clinoptilolite particles were used.

  11. Struvite crystal growth inhibition by trisodium citrate and the formation of chemical complexes in growth solution

    NASA Astrophysics Data System (ADS)

    Prywer, Jolanta; Mielniczek-Brzóska, Ewa; Olszynski, Marcin

    2015-05-01

    Effect of trisodium citrate on the crystallization of struvite was studied. To evaluate such an effect an experiment of struvite growth from artificial urine was performed. The investigations are related to infectious urinary stones formation. The crystallization process was induced by the addition of aqueous ammonia solution to mimic the bacterial activity. The spectrophotometric results demonstrate that trisodium citrate increases induction time with respect to struvite formation and decreases the growth efficiency of struvite. The inhibitory effect of trisodium citrate on the nucleation and growth of struvite is explained in base of chemical speciation analysis. Such an analysis demonstrates that the inhibitory effect is related with the fact that trisodium citrate binds NH4 + and Mg2+ ions in the range of pH from 7 to 9.5 characteristic for struvite precipitation. The most important is the MgCit- complex whose concentration strongly depends on an increase in pH rather than on an increase in citrate concentrations.

  12. Colonic cleansing for radiographic detection of neoplasia: efficacy of the magnesium citrate-castor oil-cleansing enema regimen.

    PubMed

    Gelfand, D W; Chen, Y M; Ott, D J

    1988-10-01

    To optimize detection of colonic polyps, we instituted a cleansing regimen of dietary restriction, hydration, magnesium citrate, castor oil, and a cleansing enema. We then conducted a review of serially performed barium enemas to determine the percentage of patients with clean colons in a mixed population of 500 inpatients and outpatients in whom this regimen had been used. The same regimen also was used before single- and double-contrast barium enemas were performed in 139 patients with 234 polyps, and radiologic-endoscopic correlation was used to determine the percentage of polypoid neoplasms detected. The review indicated that a clean colon had been achieved in 97% of the 500 cases. In an additional 1.4% of patients, fecal residue was limited to small amounts in the cecum or ascending colon. In only two cases (0.4%) did fecal material prevent an examination that was suitable for detection of large polypoid or circumferential lesions. The single- and double-contrast barium enemas detected 80% and 91%, respectively, of polypoid lesions of all sizes. Single-contrast examinations detected 94% of polyps 10 mm or larger and 72% of polyps 5-9 mm. Double-contrast studies detected 96% of polyps 10 mm or larger and 88% of those 5-9 mm. The results of this study indicate that with this regimen, fecal residue does not significantly interfere with the detection of colonic polyps via barium enema examination.

  13. Comparative genomics and transcriptome analysis of Aspergillus niger and metabolic engineering for citrate production

    PubMed Central

    Yin, Xian; Shin, Hyun-dong; Li, Jianghua; Du, Guocheng; Liu, Long; Chen, Jian

    2017-01-01

    Despite a long and successful history of citrate production in Aspergillus niger, the molecular mechanism of citrate accumulation is only partially understood. In this study, we used comparative genomics and transcriptome analysis of citrate-producing strains—namely, A. niger H915-1 (citrate titer: 157 g L−1), A1 (117 g L−1), and L2 (76 g L−1)—to gain a genome-wide view of the mechanism of citrate accumulation. Compared with A. niger A1 and L2, A. niger H915-1 contained 92 mutated genes, including a succinate-semialdehyde dehydrogenase in the γ-aminobutyric acid shunt pathway and an aconitase family protein involved in citrate synthesis. Furthermore, transcriptome analysis of A. niger H915-1 revealed that the transcription levels of 479 genes changed between the cell growth stage (6 h) and the citrate synthesis stage (12 h, 24 h, 36 h, and 48 h). In the glycolysis pathway, triosephosphate isomerase was up-regulated, whereas pyruvate kinase was down-regulated. Two cytosol ATP-citrate lyases, which take part in the cycle of citrate synthesis, were up-regulated, and may coordinate with the alternative oxidases in the alternative respiratory pathway for energy balance. Finally, deletion of the oxaloacetate acetylhydrolase gene in H915-1 eliminated oxalate formation but neither influence on pH decrease nor difference in citrate production were observed. PMID:28106122

  14. Natural DNA mixed with trehalose persists in B-form double-stranding even in the dry state.

    PubMed

    Zhu, Bo; Furuki, Takao; Okuda, Takashi; Sakurai, Minoru

    2007-05-24

    Desiccated calf-thymus DNA has been found to persist in the B-form double-stranding when mixed with trehalose. The stabilization effect on natural DNA depends on the trehalose content, and should basically arise from its ability to tightly hydrogen bond to phosphate groups of DNA, which leads to screening of the large phosphate-phosphate repulsion.

  15. WRKY42 Modulates Phosphate Homeostasis through Regulating Phosphate Translocation and Acquisition in Arabidopsis1[OPEN

    PubMed Central

    Su, Tong; Xu, Qian; Zhang, Fei-Cui; Chen, Yun; Li, Li-Qin; Wu, Wei-Hua; Chen, Yi-Fang

    2015-01-01

    The Arabidopsis (Arabidopsis thaliana) WRKY transcription factor family has more than 70 members, and some of them have been reported to play important roles in plant response to biotic and abiotic stresses. This study shows that WRKY42 regulated phosphate homeostasis in Arabidopsis. The WRKY42-overexpressing lines, similar to the phosphate1 (pho1) mutant, were more sensitive to low-inorganic phosphate (Pi) stress and had lower shoot Pi content compared with wild-type plants. The PHO1 expression was repressed in WRKY42-overexpressing lines and enhanced in the wrky42 wrky6 double mutant. The WRKY42 protein bound to the PHO1 promoter under Pi-sufficient condition, and this binding was abrogated during Pi starvation. These data indicate that WRKY42 modulated Pi translocation by regulating PHO1 expression. Furthermore, overexpression of WRKY42 increased root Pi content and Pi uptake, whereas the wrky42 mutant had lower root Pi content and Pi uptake rate compared with wild-type plants. Under Pi-sufficient condition, WRKY42 positively regulated PHOSPHATE TRANSPORTER1;1 (PHT1;1) expression by binding to the PHT1;1 promoter, and this binding was abolished by low-Pi stress. During Pi starvation, the WRKY42 protein was degraded through the 26S proteasome pathway. Our results showed that AtWRKY42 modulated Pi homeostasis by regulating the expression of PHO1 and PHT1;1 to adapt to environmental changes in Pi availability. PMID:25733771

  16. 77 FR 22560 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-16

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... acid and certain citrate salts (``citric acid'') from the People's Republic of China (``PRC'').\\1\\ On...). \\2\\ See Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of...

  17. 77 FR 56188 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Notice of Rescission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-12

    ... International Trade Administration Citric Acid and Certain Citrate Salts from the People's Republic of China... of the countervailing duty (CVD) order on citric acid and certain citrate salts from the People's...\\ See Citric Acid and Certain Citrate Salts from the People's Republic of China: Intent to...

  18. 77 FR 72323 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-05

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... certain citrate salts from the People's Republic of China for the period January 1, 2010, through December... Acid and Certain Citrate Salts from the People's Republic of China: Preliminary Results...

  19. 76 FR 82275 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-30

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... countervailing duty order on citric acid and certain citrate salts from the People's Republic of China (PRC). See... and Certain Citrate Salts, 74 FR 25705 (May 29, 2009). On May 2, 2011, the Department published...

  20. 77 FR 9891 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Amended Final Results...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-21

    ... International Trade Administration Citric Acid and Certain Citrate Salts from the People's Republic of China... antidumping duty order on citric acid and certain citrate salts (``citric acid'') from the People's Republic... Act of 1930, as amended (``the Act''). \\1\\ See Citric Acid and Certain Citrate Salts from the...

  1. 77 FR 74171 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... certain citrate salts from the People's Republic of China (``PRC'') on June 6, 2012.\\1\\ The period of... Citric Acid and Certain Citrate Salts from the People's Republic of China: Post- Preliminary...

  2. 76 FR 77772 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Final Results of the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... International Trade Administration Citric Acid and Certain Citrate Salts from the People's Republic of China... of the antidumping duty order on citric acid and certain citrate salts (``citric acid'') from the... Citric Acid and Certain Citrate Salts from the People's Republic of China: Preliminary Results of...

  3. 76 FR 33219 - Citric Acid and Certain Citrate Salts from the People's Republic of China: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-08

    ... International Trade Administration Citric Acid and Certain Citrate Salts from the People's Republic of China... administrative review of the countervailing duty order on citric acid and certain citrate salts from the People's... countervailing duty order on citric acid and certain citrate salts (``citric acid'') from the People's...

  4. 76 FR 17835 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-31

    ... International Trade Administration A-570-937] Citric Acid and Certain Citrate Salts From the People's Republic... order on citric acid and certain citrate salts (``citric acid'') from the People's Republic of China.... See Citric Acid and Certain Citrate Salts from the People's Republic of China: Notice of Extension...

  5. Calcium Phosphates and Human Beings

    NASA Astrophysics Data System (ADS)

    Dorozhkin, Sergey V.

    2006-05-01

    This article describes the general importance of calcium phosphates for human beings. The basic information on the structure and chemical properties of the biologically relevant calcium phosphates is summarized. Basic facts on the natural occurrence and the industrial use of natural calcium phosphates are discussed. Fundamental details on the presence of calcium phosphates in major calcified tissues (bones and teeth) of humans and mammals, as well as on biomaterials made of calcium phosphates are discussed. The article will be of value for chemistry teachers for expansion of their general background and point the students' attention to the rapidly growing topic of bone-substituting biomaterials.

  6. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... Listing of Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate,...

  7. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... Listing of Specific Substances Affirmed as GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate,...

  8. 21 CFR 184.1434 - Magnesium phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Magnesium phosphate. 184.1434 Section 184.1434... GRAS § 184.1434 Magnesium phosphate. (a) Magnesium phosphate includes both magnesium phosphate, dibasic, and magnesium phosphate, tribasic. Magnesium phosphate, dibasic (MgHPO4·3H2O, CAS Reg. No....

  9. Heterotopic pregnancy following induction of ovulation with clomiphene citrate

    PubMed Central

    Ghandi, Sedigheh; Ahmadi, Raheleh; Fazel, Mahmoud

    2011-01-01

    Background: Although heterotopic gestation is common in assisted reproductive techniques, it is very rare in natural conception and clomiphene induced pregnancy. Diagnosis and appropriate intervention of heterotopic pregnancy requires a high index of suspicious. Case: In this paper a case of heterotopic pregnancy in a 30-year old woman with hemoperitoneum from ruptured tubal pregnancy with live intrauterine gestation at 9 weeks of gestation is reported. Conclusion: This case suggests that a heterotopic pregnancy must always be considered particularly after the induction of ovulation by clomiphene citrate or assisted reproductive technology. Every clinician treating women of reproductive age should keep this diagnosis in mind. It also demonstrates that early diagnosis is essential in order to salvage the intrauterine pregnancy and avoid maternal morbidity and mortality. PMID:26396583

  10. Response of patients with indolent systemic mastocytosis to tamoxifen citrate.

    PubMed

    Butterfield, Joseph H; Chen, Dong

    2016-01-01

    We examined whether tamoxifen citrate at 20mg/day for 1 year had a beneficial effect on laboratory findings, bone marrow mastocytosis, common clinical symptoms, or quality-of-life assessment for 5 women and 2 men with indolent systemic mastocytosis. Tamoxifen was well tolerated. We found significant reductions in the platelet count, serum alkaline phosphatase, and 24-h urinary excretion of N-methylhistamine and significant increases in serum lactate dehydrogenase and (excluding 2 patients taking aspirin) in 24-h urinary excretion of 11β-prostaglandin F2α. Overall, no change occurred in percent involvement of bone marrow by mastocytosis. Symptom scores were mild and did not change during the treatment. The 36-Item Short Form Health Survey scores for quality of life physical and mental components showed no marked changes. Tamoxifen, an older, nonhematotoxic medication, has limited activity in systemic mastocytosis at the dosage used in this study.

  11. Sildenafil citrate for the treatment of pulmonary hypertension.

    PubMed

    Hrometz, Sandra L; Shields, Kelly M

    2006-12-01

    Pulmonary arterial hypertension is a progressive disease that has a high rate of mortality. For these reasons, early treatment is essential. Treatment choices for pulmonary arterial hypertension are limited by drug tolerability, drug cost and inconvenience associated with administration techniques and dosing schedules. Therefore, a therapy that provides oral dosing with limited side effects would prove useful in managing many patients. Sildenafil citrate, the first and highly publicized oral medication to receive approval from the U.S. Food and Drug Administration for erectile dysfunction, has recently been approved for treatment of pulmonary arterial hypertension. This review summarizes the normal physiology of the pulmonary vasculature, and the pathophysiology involved in pulmonary arterial hypertension and the role of sildenafil in its treatment.

  12. Radium-226 in wetland birds from Florida phosphate mines

    SciTech Connect

    Myers, O.B.; Marion, W.R.; O'Meara, T.E.; Roessler, C.E. )

    1989-10-01

    Radium-226 is a naturally-occurring radionuclide found in enhanced levels at Florida phosphate mines. We inventoried levels of radium-226 in the tissues of 4 wetland bird species from 2 mined and 2 umined areas in Florida. Bone tissues of wood duck (Aix sponsa), mottled duck (Anas fulvigula), common moorhen (Gallinula chloropus), and double-crested cormorant (Phalacrocorax auritus) colleted at phosphate mines contained more radium-226 than tissues from unmined areas. Radium-226 concentrations in these birds were within guidelines inferred from radiological standards designed for human protection and should not adversely affect bird populations.

  13. [Double responses].

    PubMed

    Motté, G; Dinanian, S; Sebag, C; Drieu, L; Slama, M

    1995-12-01

    Double response is a rare electrocardiographic phenomenon requiring two atrioventricular conduction pathways with very different electrophysiological properties. Double ventricular responses are the usual manifestation: an atrial depolarisation (spontaneous or provoked, anticipated or not) is followed by a first ventricular response dependent on an accessory pathway or a rapid nodal pathway and then a second response resulting from sufficiently delayed transmission through a nodal pathway for the ventricles to have recovered their excitability when the second wave of activation reaches them. A simple curiosity when isolated and occurring under unusual conditions, particularly during electrophysiological investigation of the Wolff-Parkinson-White syndrome, the double response may initiate symptomatic non-reentrant junctional tachycardia when associated with nodal duality and repeating from atria in sinus rhythm. The functional incapacity and resistance to antiarrhythmic therapy may require referral for ablation of the slow pathway.

  14. Biomediated continuous release phosphate fertilizer

    DOEpatents

    Goldstein, Alan H.; Rogers, Robert D.

    1999-01-01

    A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed.

  15. Biomediated continuous release phosphate fertilizer

    DOEpatents

    Goldstein, A.H.; Rogers, R.D.

    1999-06-15

    A composition is disclosed for providing phosphate fertilizer to the root zone of plants. The composition comprises a microorganism capable of producing and secreting a solubilization agent, a carbon source for providing raw material for the microorganism to convert into the solubilization agent, and rock phosphate ore for providing a source of insoluble phosphate that is solubilized by the solubilization agent and released as soluble phosphate. The composition is provided in a physical form, such as a granule, that retains the microorganism, carbon source, and rock phosphate ore, but permits water and soluble phosphate to diffuse into the soil. A method of using the composition for providing phosphate fertilizer to plants is also disclosed. 13 figs.

  16. Renal phosphate handling: Physiology

    PubMed Central

    Prasad, Narayan; Bhadauria, Dharmendra

    2013-01-01

    Phosphorus is a common anion. It plays an important role in energy generation. Renal phosphate handling is regulated by three organs parathyroid, kidney and bone through feedback loops. These counter regulatory loops also regulate intestinal absorption and thus maintain serum phosphorus concentration in physiologic range. The parathyroid hormone, vitamin D, Fibrogenic growth factor 23 (FGF23) and klotho coreceptor are the key regulators of phosphorus balance in body. PMID:23961477

  17. Genome-wide identification of citrus ATP-citrate lyase genes and their transcript analysis in fruits reveals their possible role in citrate utilization.

    PubMed

    Hu, Xiao-Mei; Shi, Cai-Yun; Liu, Xiao; Jin, Long-Fei; Liu, Yong-Zhong; Peng, Shu-Ang

    2015-02-01

    ATP-citrate lyase (ACL, EC4.1.3.8) catalyzes citrate to oxaloacetate and acetyl-CoA in the cell cytosol, and has important roles in normal plant growth and in the biosynthesis of some secondary metabolites. We identified three ACL genes, CitACLα1, CitACLα2, and CitACLβ1, in the citrus genome database. Both CitACLα1 and CitACLα2 encode putative ACL α subunits with 82.5 % amino acid identity, whereas CitACLβ1 encodes a putative ACL β subunit. Gene structure analysis showed that CitACLα1 and CitACLα2 had 12 exons and 11 introns, and CitACLβ1 had 16 exons and 15 introns. CitACLα1 and CitACLβ1 were predominantly expressed in flower, and CitACLα2 was predominantly expressed in stem and fibrous roots. As fruits ripen, the transcript levels of CitACLα1, CitACLβ1, and/or CitACLα2 in cultivars 'Niuher' and 'Owari' increased, accompanied by significant decreases in citrate content, while their transcript levels decreased significantly in 'Egan No. 1' and 'Iyokan', although citrate content also decreased. In 'HB pummelo', in which acid content increased as fruit ripened, and in acid-free pummelo, transcript levels of CitACLα2, CitACLβ1, and/or CitACLα1 increased. Moreover, mild drought stress and ABA treatment significantly increased citrate contents in fruits. Transcript levels of the three genes were significantly reduced by mild drought stress, and the transcript level of only CitACLβ1 was significantly reduced by ABA treatment. Taken together, these data indicate that the effects of ACL on citrate use during fruit ripening depends on the cultivar, and the reduction in ACL gene expression may be attributed to citrate increases under mild drought stress or ABA treatment.

  18. Citrate anticoagulation during plasma exchange in a patient with thrombotic thrombocytopenic purpura: short heparin-free hemodialysis helps to attenuate citrate load.

    PubMed

    Buturović-Ponikvar, Jadranka; Pernat, Andreja Marn; Ponikvar, Rafael

    2005-06-01

    The treatment of thrombotic thrombocytopenic purpura requires plasma exchange using fresh frozen plasma as a replacement solution once or even twice daily. If citrate anticoagulation is needed, the citrate load (both from fresh frozen plasma and citrate as an anticoagulant) can be significant, causing metabolic complications. The aim of our report is to present our experience with citrate anticoagulation in a patient with thrombotic thrombocytopenic purpura treated with daily membrane plasma exchange. Twenty-six plasma exchange procedures were performed during 20 days of treatment in a 46-year-old female. The blood flow was 98 +/- 8 mL/min; 4% trisodium citrate was infused into the arterial line (134 +/- 11 mL/h) and 1 M CaCl2 into the venous line (11.4 +/- 1.8 mL/h). Fresh frozen plasma (first 7 procedures) or cryo-poor plasma (19 procedures) were used as a replacement solution, 3176 +/- 536 mL per procedure. A total of 88,930 mL of plasma was exchanged. No serious side-effects occurred. iCa before plasma exchange was significantly higher than afterwards (1.23 +/- 0.12 vs. 1.12 +/- 0.12, P = 0.0047). Significant alkalosis occurred after three plasma exchanges (pH 7.64, bicarbonate 36.2 mmol/L), and was corrected by 3-h heparin-free hemodialysis with dialysate as follows: K 4.0 mmol/L, calcium 1.5 mmol/L, and bicarbonate set to 24 mmol/L. After dialysis, pH was 7.45 and bicarbonate 29.4 mmol/L. Another (2-h) heparin-free hemodialysis procedure was repeated after six plasma exchanges. Citrate anticoagulation can be safely performed in patients treated with plasma exchange once or twice daily. Periodically performed short heparin-free hemodialysis can correct metabolic alkalosis and attenuate the citrate load.

  19. Effect of phosphate supplementation on oxygen delivery at high altitude

    NASA Astrophysics Data System (ADS)

    Jain, S. C.; Singh, M. V.; Rawal, S. B.; Sharma, V. M.; Divekar, H. M.; Tyagi, A. K.; Panwar, M. R.; Swamy, Y. V.

    1987-09-01

    In the present communication, effect of low doses of phosphate supplementation on short-term high altitude adaptation has been examined. Studies were carried out in 36 healthy, male, sea-level residents divided in a double blind fashion into drug and placebo treated groups. 3.2 mmol of phosphate were given orally to each subject of the drug treated group once a day for 4 days on arrival at an altitude of 3,500 m. Sequential studies were done in the subjects in both groups on the 3rd, 7th, 14th and 21st day of their altitude stay. Haemoglobin, haematocrit, erythrocyte and reticulocyte counts increased to the similar extent in both groups. Blood pH, pO2 and adenosine tri-phosphate (ATP) did not differ between the two groups. On 3rd day of the altitude stay, inorganic phosphate and 2,3-diphosphoglycerate (2,3 DPG) levels in the drug treated group increased significantly as compared to the placebo group. No significant difference in inorganic phosphate and 2,3 DPG was observed later on in the two groups. Psychological and clinical tests also indicated that the drug treated subjects felt better as compared to the placebo treated subjects. The present study suggests that low doses of phosphate increases circulating 2,3-DPG concentration which in turn brings about beneficial effect towards short term high altitude adaptation.

  20. Comparative transcriptome analysis reveals a global insight into molecular processes regulating citrate accumulation in sweet orange (Citrus sinensis).

    PubMed

    Lu, Xiaopeng; Cao, Xiongjun; Li, Feifei; Li, Jing; Xiong, Jiang; Long, Guiyou; Cao, Shangyin; Xie, Shenxi

    2016-12-01

    Citrate, the predominant organic acid in citrus, determines the taste of these fruits. However, little is known about the synergic molecular processes regulating citrate accumulation. Using 'Dahongtiancheng' (Citrus sinensis) and 'Bingtangcheng' (C. sinensis) with significant difference in citrate, the objectives of this study were to understand the global mechanisms of high-citrate accumulation in sweet orange. 'Dahongtiancheng' and 'Bingtangcheng' exhibit significantly different patterns in citrate accumulation throughout fruit development, with the largest differences observed at 50-70 days after full bloom (DAFB). Comparative transcriptome profiling was performed for the endocarps of both cultivars at 50 and 70 DAFB. Over 34.5 million clean reads per library were successfully mapped to the reference database and 670-2630 differentially expressed genes (DEGs) were found in four libraries. Among the genes, five transcription factors were ascertained to be the candidates regulating citrate accumulation. Functional assignments of the DEGs indicated that photosynthesis, the citrate cycle and amino acid metabolism were significantly altered in 'Dahongtiancheng'. Physiological and molecular analyses suggested that high photosynthetic efficiency and partial impairment of citrate catabolism were crucial for the high-citrate trait, and amino acid biosynthesis was one of the important directions for citrate flux. The results reveal a global insight into the gene expression changes in a high-citrate compared with a low-citrate sweet orange. High accumulating efficiency and impaired degradation of citrate may be associated with the high-citrate trait of 'Dahongtiancheng'. Findings in this study increase understanding of the molecular processes regulating citrate accumulation in sweet orange.

  1. The Citrate Carrier CitS Probed by Single-Molecule Fluorescence Spectroscopy

    PubMed Central

    Kästner, Christopher N.; Prummer, Michael; Sick, Beate; Renn, Alois; Wild, Urs P.; Dimroth, Peter

    2003-01-01

    A prominent region of the Na+-dependent citrate carrier (CitS) from Klebsiella pneumoniae is the highly conserved loop X-XI, which contains a putative citrate binding site. To monitor potential conformational changes within this region by single-molecule fluorescence spectroscopy, the target cysteines C398 and C414 of the single-Cys mutants (CitS-sC398, CitS-sC414) were selectively labeled with the thiol-reactive fluorophores AlexaFluor 546/568 C5 maleimide (AF546, AF568). While both single-cysteine mutants were catalytically active citrate carriers, labeling with the fluorophore was only tolerated at C398. Upon citrate addition to the functional protein fluorophore conjugate CitS-sC398-AF546, complete fluorescence quenching of the majority of molecules was observed, indicating a citrate-induced conformational change of the fluorophore-containing domain of CitS. This quenching was specific for the physiological substrate citrate and therefore most likely reflecting a conformational change in the citrate transport mechanism. Single-molecule studies with dual-labeled CitS-sC398-AF546/568 and dual-color detection provided strong evidence for a homodimeric association of CitS. PMID:12609868

  2. Regulation of Stalk Elongation by Phosphate in Caulobacter crescentus

    PubMed Central

    Gonin, Madeleine; Quardokus, Ellen M.; O'Donnol, Danielle; Maddock, Janine; Brun, Yves V.

    2000-01-01

    In Caulobacter crescentus, stalk biosynthesis is regulated by cell cycle cues and by extracellular phosphate concentration. Phosphate-starved cells undergo dramatic stalk elongation to produce stalks as much as 30 times as long as those of cells growing in phosphate-rich medium. To identify genes involved in the control of stalk elongation, transposon mutants were isolated that exhibited a long-stalk phenotype irrespective of extracellular phosphate concentration. The disrupted genes were identified as homologues of the high-affinity phosphate transport genes pstSCAB of Escherichia coli. In E. coli, pst mutants have a constitutively expressed phosphate (Pho) regulon. To determine if stalk elongation is regulated by the Pho regulon, the Caulobacter phoB gene that encodes the transcriptional activator of the Pho regulon was cloned and mutated. While phoB was not required for stalk synthesis or for the cell cycle timing of stalk synthesis initiation, it was required for stalk elongation in response to phosphate starvation. Both pstS and phoB mutants were deficient in phosphate transport. When a phoB mutant was grown with limiting phosphate concentrations, stalks only increased in length by an average of 1.4-fold compared to the average 9-fold increase in stalk length of wild-type cells grown in the same medium. Thus, the phenotypes of phoB and pst mutants were opposite. phoB mutants were unable to elongate stalks during phosphate starvation, whereas pst mutants made long stalks in both high- and low-phosphate media. Analysis of double pst phoB mutants indicated that the long-stalk phenotype of pst mutants was dependent on phoB. In addition, analysis of a pstS-lacZ transcriptional fusion showed that pstS transcription is dependent on phoB. These results suggest that the signal transduction pathway that stimulates stalk elongation in response to phosphate starvation is mediated by the Pst proteins and the response regulator PhoB. PMID:10629178

  3. Citrate-enhanced release of arsenic during pyrite oxidation at circumneutral conditions.

    PubMed

    Zhang, Peng; Yao, Weiyu; Yuan, Songhu

    2017-02-01

    The release of arsenic (As) from the oxidation of As-rich pyrite is an important source of the high arsenic in groundwater. As a widespread low-molecular-weight organic acid, citrate plays an important role on the cycling of Fe(II)/Fe(III) through complexation in circumneutral subsurface environments, while the influence of citrate on the release of As from the oxidation of As-rich pyrite is poorly understood. In this study, As was loaded onto pyrite particles under anoxic conditions, and its release was investigated in the presence of 0-1 mM citrate at pH 7.4 under oxic conditions. As-loaded pyrite suspension was prepared by the equilibrium of 2.67 μM As(III) in 10 g/L pyrite under anoxic conditions with the decrease in dissolved As(III) concentration to 1 μM. The suspension was subsequently exposed to air for oxygenation. In the absence of citrate, the oxygenation decreased the partitioning of As in the solution because of the re-adsorption of aqueous As by the in situ generated Fe(III) oxyhydroxides. However, with the increase in citrate concentration from 0.1 to 1 mM, the As partitioned in the solution increased from 0.3 to 2.67 μM. In the presence of 1 mM citrate, the As(III) was almost completely oxidized to As(V) during the oxygenation. The mechanisms of citrate-enhanced release of As were mainly attributed to the ligand exchange of citrate with As for pyrite surface sites, the competitive adsorption of citrate with As on Fe(III) oxyhydroxides and pyrite, and the partitioning of As on the newly formed Fe(III) colloids. This finding presents an overlooked mechanism of the release of pyrite-associated As under oxic and circumneutral conditions.

  4. Physiologically relevant divalent cations modulate citrate recognition by the McpS chemoreceptor.

    PubMed

    Lacal, Jesús; García-Fontana, Cristina; Callejo-García, Carla; Ramos, Juan-Luis; Krell, Tino

    2011-01-01

    The McpS chemoreceptor of Pseudomonas putida KT2440 recognizes six different tricarboxylic acid (TCA) cycle intermediates. However, the magnitude of the chemotactic response towards these compounds differs largely, which has led to distinguish between strong attractants (malate, succinate, fumarate, oxaloacetate) and weak attractants (citrate, isocitrate). Citrate is abundantly present in plant tissues and root exudates and can serve as the only carbon source for growth. Citrate is known to form complexes with divalent cations which are also abundantly present in natural habitats of this bacterium. We have used isothermal titration calorimetry to study the formation of citrate-metal ion complexes. In all cases binding was entropy driven but significant differences in affinity were observed ranging from K(D)=157 µM (for Mg(2+)) to 3 µM (for Ni(2+)). Complex formation occurred over a range of pH and ionic strength. The ligand binding domain of McpS (McpS-LBD) was found to bind free citrate, but not complexes with physiologically relevant Mg(2+) and Ca(2+). In contrast, complexes with divalent cations which are present as trace elements (Co(2+), Cd(2+) and Ni(2+)) were recognized by McpS-LBD. This discrimination differs from other citrate sensing proteins. These results are discussed in the context of the three dimensional structure of free citrate and its complex with Mg(2+). Chemotaxis assays using P. putida revealed that taxis towards the strong attractant malate is strongly reduced in the presence of free citrate. However, this reduction is much less important in the presence of citrate-Mg(2+) complexes. The physiological relevance of these findings is discussed.

  5. Effect of volume expansion on renal citrate and ammonia metabolism in KCl-deficient rats.

    PubMed Central

    Adler, S; Zett, B; Anderson, B; Fraley, D S

    1975-01-01

    When rats with desoxycorticosterone acetate (DOCA)-induced potassium chloride deficiency are given sodium chloride there is simultaneously a partial correction of metabolic alkalosis and a marked reduction in urinary citrate excretion and renal citrate content. To examine DOCA's role in this phenomenon and to determine how sodium chloride alters renal metabolism, rats were made KC1 deficient using furosemide and a KC1-deficient diet. Renal citrate and ammonia metabolism were then studied after chronic oral sodium chloride administration or acute volume expansion with isotonic mannitol. Although both maneuvers partially corrected metabolic alkalosis, sodium chloride raised serum chloride concentration while mannitol significantly decreased it. Urinary citrate excretion decreased to 10% of control in rats given NaCl and to 50% of control in rats infused with mannitol. The filtered load of citrate was constant or increased indicating increased tubular citrate reabsorption. Renal cortical citrate content also decreased approximately 50%. Renal cortical slices from KCl-deficient rats incubated in low or normal chloride media produced equal amounts of 14CO2 from (1, 5-14C) citrate. In addition, urinary ammonia excretion increased by over 300% in both groups. This occurred in the mannitol group despite increased urinary pH and flow rate indicating a rise in renal ammonia production. It seems that neither DOCA nor an increase in serum chloride concentration explains the experimental results. Rather, it appears that volume expansion is responsible for increased renal tubular citrate reabsorption and renal ammonia production. As these renal metabolic responses ordinarily occur in response to acidosis, the data are consistent with the hypothesis that volume expansion reduces renal cell pH in 3KCl-deficient rats. PMID:239022

  6. Continuous venovenous hemodialysis with regional citrate anticoagulation in patients with liver failure: a prospective observational study

    PubMed Central

    2012-01-01

    Introduction Liver failure patients might be at risk for citrate accumulation during continuous venovenous hemodialysis (CVVHD) with regional citrate anticoagulation. The aim of this study was to investigate the predictive capability of baseline liver function parameters regarding citrate accumulation, expressed as an increase in the calcium total/calcium ionized (Catot/Caion) ratio ≥2.5, and to describe the feasibility of citrate CVVHD in liver failure patients. Methods We conducted a prospective observational study in medical ICU patients treated in a German university hospital. We performed 43 CVVHD runs using citrate for regional anticoagulation in 28 critically ill patients with decompensated liver cirrhosis or acute liver failure (maximum of two CVVHD runs per patient). Liver function was characterized before CVVHD using laboratory parameters, calculation of Child-Pugh and Model of End-stage Liver Disease scores, and determination of the plasma disappearance rate of indocyanine green. In addition to blood gas analysis, we measured total calcium and citrate in serum at baseline and after definitive time points for each CVVHD run. Results Accumulation of citrate in serum correlated with an increase in the Catot/Caion ratio. Although the critical upper threshold of Catot/Caion ratio ≥2.5 was exceeded 10 times in seven different CVVHD runs, equalization of initial metabolic acidosis was possible without major disturbances of acid-base and electrolyte status. Standard laboratory liver function parameters showed poor predictive capabilities regarding citrate accumulation in terms of an elevated Catot/Caion ratio ≥2.5. In contrast, serum lactate ≥3.4 mmol/l and prothrombin time ≤26% predicted an increase in the Catot/Caion ratio ≥2.5 with high sensitivity (86% for both lactate and prothrombin time) and specificity (86% for lactate, 92% for prothrombin time). Conclusions Despite substantial accumulation of citrate in serum, CVVHD with regional citrate

  7. Purification of L-glutamate-dependent citrate lyase from Clostridium sphenoides and electron microscopic analysis of citrate lyase isolated from Rhodopseudomonas gelatinosa, Streptococcus diacetilactis and C. sphenoides.

    PubMed

    Antranikian, G; Klinner, C; Kümmel, A; Schwanitz, D; Zimmermann, T; Mayer, F; Gottschalk, G

    1982-08-01

    Citrate lyase from Clostridium sphenoides was purified 72-fold with a yield of 11%. In contrast to citrate lyase from other sources the activity of this enzyme was strictly dependent on the presence of L-glutamate. The purified enzyme was only stable in the presence of 150 mM L-glutamate or 7 mM L-glutamate plus glycerol, sucrose or bovine serum albumin. Changes of the L-glutamate pool and of enzyme activity in growing cells of C. sphenoides indicated that citrate lyase activity in this organism was regulated by the intracellular L-glutamate concentration. Citrate lyase isolated from C. sphenoides, Rhodopseudomonas gelatinosa and Streptococcus diacetilactis was investigated by electron microscopy using the negative staining technique. Three different projections of enzyme molecules were observed: 'star' form, 'ring' form and 'triangle' form. In samples from R. gelatinosa and S. diacetilactis, star and ring forms occurred in a ratio of about 1:9. Using the enzyme from S. diacetilactis it was demonstrated that this ratio could be altered in favour of the star form by the addition of citrate or tricarballylate. The triangle form was observed in less than 1% of all evaluated molecules and may represent a transition form. In lyase samples from C. sphenoides there existed a correlation between enzyme activity and the proportion of stars and rings at varying concentrations of L-glutamate.

  8. Phosphate May Promote CKD Progression and Attenuate Renoprotective Effect of ACE Inhibition

    PubMed Central

    Ruggenenti, Piero; Perna, Annalisa; Leonardis, Daniela; Tripepi, Rocco; Tripepi, Giovanni; Mallamaci, Francesca; Remuzzi, Giuseppe

    2011-01-01

    Phosphate may promote the onset and progression of chronic nephropathies. Here we evaluated the relationships between baseline serum phosphate levels, disease progression, and response to ACE inhibition in 331 patients with proteinuric nephropathies in the prospective Ramipril Efficacy In Nephropathy (REIN) trial. Independent of treatment, patients with phosphate levels in the highest two quartiles progressed significantly faster either to ESRD or to a composite endpoint of doubling of serum creatinine or ESRD compared with patients with phosphate levels below the median (P < 0.001). Results were similar when we analyzed phosphate as a continuous variable (P ≤ 0.004). The renoprotective effect of ramipril decreased as serum phosphate increased (P ≤ 0.008 for interaction); this modification of the treatment effect by phosphate persisted despite adjusting for potential confounders such as GFR and urinary protein. In summary, these data suggest that phosphate is an independent risk factor for progression of renal disease among patients with proteinuric CKD, and high levels of phosphate may even attenuate the renoprotective effect of ACE inhibitors. Future trials should test whether reducing serum phosphate improves renal outcomes and optimizes the renoprotective effect of ACE inhibition. PMID:21852581

  9. Brushite-based calcium phosphate cement with multichannel hydroxyapatite granule loading for improved bone regeneration.

    PubMed

    Sarkar, Swapan Kumar; Lee, Byung Yeol; Padalhin, Andrew Reyas; Sarker, Avik; Carpena, Nathaniel; Kim, Boram; Paul, Kallyanshish; Choi, Hwan Jun; Bae, Sang-Ho; Lee, Byong Taek

    2016-01-01

    In this work, we report brushite-based calcium phosphate cement (CPC) system to enhance the in vivo biodegradation and tissue in-growth by incorporation of micro-channeled hydroxyapatite (HAp) granule and silicon and sodium addition in calcium phosphate precursor powder. Sodium- and silicon-rich calcium phosphate powder with predominantly tri calcium phosphate (TCP) phase was synthesized by an inexpensive wet chemical route to react with mono calcium phosphate monohydrate (MCPM) for making the CPC. TCP nanopowder also served as a packing filler and moderator of the reaction kinetics of the setting mechanism. Strong sintered cylindrical HAp granules were prepared by fibrous monolithic (FM) process, which is 800 µm in diameter and have seven micro-channels. Acid sodium pyrophosphate and sodium citrate solution was used as the liquid component which acted as a homogenizer and setting time retarder. The granules accelerated the degradation of the brushite cement matrix as well as improved the bone tissue in-growth by permitting an easy access to the interior of the CPC through the micro-channels. The addition of micro-channeled granule in the CPC introduced porosity without sacrificing much of its compressive strength. In vivo investigation by creating a critical size defect in the femur head of a rabbit model for 1 and 2 months showed excellent bone in-growth through the micro-channels. The granules enhanced the implant degradation behavior and bone regeneration in the implanted area was significantly improved after two months of implantation.

  10. A Process-Based Model of TCA Cycle Functioning to Analyze Citrate Accumulation in Pre- and Post-Harvest Fruits

    PubMed Central

    Etienne, Audrey; Génard, Michel; Bugaud, Christophe

    2015-01-01

    Citrate is one of the most important organic acids in many fruits and its concentration plays a critical role in organoleptic properties. The regulation of citrate accumulation throughout fruit development, and the origins of the phenotypic variability of the citrate concentration within fruit species remain to be clarified. In the present study, we developed a process-based model of citrate accumulation based on a simplified representation of the TCA cycle to predict citrate concentration in fruit pulp during the pre- and post-harvest stages. Banana fruit was taken as a reference because it has the particularity of having post-harvest ripening, during which citrate concentration undergoes substantial changes. The model was calibrated and validated on the two stages, using data sets from three contrasting cultivars in terms of citrate accumulation, and incorporated different fruit load, potassium supply, and harvest dates. The model predicted the pre and post-harvest dynamics of citrate concentration with fairly good accuracy for the three cultivars. The model suggested major differences in TCA cycle functioning among cultivars during post-harvest ripening of banana, and pointed to a potential role for NAD-malic enzyme and mitochondrial malate carriers in the genotypic variability of citrate concentration. The sensitivity of citrate accumulation to growth parameters and temperature differed among cultivars during post-harvest ripening. Finally, the model can be used as a conceptual basis to study citrate accumulation in fleshy fruits and may be a powerful tool to improve our understanding of fruit acidity. PMID:26042830

  11. Structure of dihydroxyacetone phosphate dimethyl acetal, a stable dihydroxyacetone phosphate precursor, in the crystalline state.

    PubMed

    Slepokura, Katarzyna; Lis, Tadeusz

    2006-03-20

    Crystal and molecular structures of four different salts of a dihydroxyacetone phosphate (DHAP) precursor, its dimethyl acetal [2,2-dimethoxy-1,3-propanediol phosphate, C(5)H(13)O(7)P, (MeO)(2)DHAP]: (cha)(2)[(MeO)(2)DHAP].H(2)O (6a), (cha)[(MeO)(2)DHAP] (6b), Na(2)[(MeO)(2)DHAP].5.75H(2)O (6c) and K(2)[(MeO)(2)DHAP].H(2)O (6d), along with the cyclohexylammonium (cha) salt of its phenyl ester (cha)[(MeO)(2)DHAP(Ph)] (6e) are described. In the (MeO)(2)DHAP mono- and dianions, slightly different orientation of the phosphate group in relation to the acetal carbon atom is observed, with a delicate tendency of phosphate group to be located antiperiplanar in the monoanions and anticlinal in the dianions. The 2,2-dimethoxy-1,3-propandiol moiety, (MeO)(2)DHA, seems to be very rigid and its conformation is independent of phosphorylation, the ionization state of the inserted phosphate group and its additional substitution. The overall structures of the cyclohexylammonium (6a,b) and potassium salts (6d) have a double-layered architecture, while the sodium cation network in 6c forms the system of channels, which are filled up with the [(MeO)(2)DHAP](2-) ions. The different architectures of 6c and 6d crystals result from the different ways in which the relevant dianions coordinate to sodium and potassium ions and affect also the hydrogen bonding system observed in 6c and 6d crystals.

  12. Citrate Attenuates Adenine-Induced Chronic Renal Failure in Rats by Modulating the Th17/Treg Cell Balance.

    PubMed

    Ou, Yan; Li, Shuiqin; Zhu, Xiaojing; Gui, Baosong; Yao, Ganglian; Ma, Liqun; Zhu, Dan; Fu, Rongguo; Ge, Heng; Wang, Li; Jia, Lining; Tian, Lifang; Duan, Zhaoyang

    2016-02-01

    Citrate is commonly used as an anticoagulant in hemodialysis for chronic renal failure (CRF) and for the regulation of the immune dysfunction in CRF patients. The objective of this study was to investigate the effect of citrate on the balance of T helper 17 (Th17) and regulatory T (Treg) cells in CRF. The levels of blood urea nitrogen (BUN) and serum creatinine (Scr) were significantly increased in the CRF model group compared to the control group, and were decreased in the citrate-treated groups. Citrate treatment inhibited the viability of Th17 cells while elevating the viability of Treg cells in CRF rats. Moreover, Th17-related cytokines significantly decreased while the Treg-related cytokines significantly increased with citrate treatment. Moreover, citrate had a negative influence on the deviation of Th17/Treg cells in CRF rats. Therefore, our study suggests that citrate had an anti-inflammatory effect on CRF through the modulation of the Th17/Treg balance.

  13. Double Layers in Astrophysics

    NASA Technical Reports Server (NTRS)

    Williams, Alton C. (Editor); Moorehead, Tauna W. (Editor)

    1987-01-01

    Topics addressed include: laboratory double layers; ion-acoustic double layers; pumping potential wells; ion phase-space vortices; weak double layers; electric fields and double layers in plasmas; auroral double layers; double layer formation in a plasma; beamed emission from gamma-ray burst source; double layers and extragalactic jets; and electric potential between plasma sheet clouds.

  14. Double screening

    SciTech Connect

    Gratia, Pierre; Hu, Wayne; Joyce, Austin; Ribeiro, Raquel H.

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  15. Preparation, characterization and optimization of sildenafil citrate loaded PLGA nanoparticles by statistical factorial design

    PubMed Central

    2013-01-01

    Background and the aim of the study The objective of the present study was to formulate and optimize nanoparticles (NPs) of sildenafil-loaded poly (lactic-co-glycolic acid) (PLGA) by double emulsion solvent evaporation (DESE) method. The relationship between design factors and experimental data was evaluated using response surface methodology. Method A Box-Behnken design was made considering the mass ratio of drug to polymer (D/P), the volumetric proportion of the water to oil phase (W/O) and the concentration of polyvinyl alcohol (PVA) as the independent agents. PLGA-NPs were successfully prepared and the size (nm), entrapment efficiency (EE), drug loading (DL) and cumulative release of drug from NPs post 1 and 8 hrs were assessed as the responses. Results The NPs were prepared in a spherical shape and the sizes range of 240 to 316 nm. The polydispersity index of size was lower than 0.5 and the EE (%) and DL (%) varied between 14-62% and 2-6%, respectively. The optimized formulation with a desirability factor of 0.9 was selected and characterized. This formulation demonstrated the particle size of 270 nm, EE of 55%, DL of 3.9% and cumulative drug release of 79% after 12 hrs. In vitro release studies showed a burst release at the initial stage followed by a sustained release of sildenafil from NPs up to 12 hrs. The release kinetic of the optimized formulation was fitted to Higuchi model. Conclusions Sildenafil citrate NPs with small particle size, lipophilic feature, high entrapment efficiency and good loading capacity is produced by this method. Characterization of optimum formulation, provided by an evaluation of experimental data, showed no significant difference between calculated and measured data. PMID:24355133

  16. Metabolic and developmental effects resulting from deletion of the citA gene encoding citrate synthase in Aspergillus nidulans.

    PubMed

    Murray, Sandra L; Hynes, Michael J

    2010-04-01

    Citrate synthase is a central activity in carbon metabolism. It is required for the tricarboxylic acid (TCA) cycle, respiration, and the glyoxylate cycle. In Saccharomyces cerevisiae and Arabidopsis thaliana, there are mitochondrial and peroxisomal isoforms encoded by separate genes, while in Aspergillus nidulans, a single gene, citA, encodes a protein with predicted mitochondrial and peroxisomal targeting sequences (PTS). Deletion of citA results in poor growth on glucose but not on derepressing carbon sources, including those requiring the glyoxylate cycle. Growth on glucose is restored by a mutation in the creA carbon catabolite repressor gene. Methylcitrate synthase, required for propionyl-coenzyme A (CoA) metabolism, has previously been shown to have citrate synthase activity. We have been unable to construct the mcsADelta citADelta double mutant, and the expression of mcsA is subject to CreA-mediated carbon repression. Therefore, McsA can substitute for the loss of CitA activity. Deletion of citA does not affect conidiation or sexual development but results in delayed conidial germination as well as a complete loss of ascospores in fruiting bodies, which can be attributed to loss of meiosis. These defects are suppressed by the creA204 mutation, indicating that McsA activity can substitute for the loss of CitA. A mutation of the putative PTS1-encoding sequence in citA had no effect on carbon source utilization or development but did result in slower colony extension arising from single conidia or ascospores. CitA-green fluorescent protein (GFP) studies showed mitochondrial localization in conidia, ascospores, and hyphae. Peroxisomal localization was not detected. However, a very low and variable detection of punctate GFP fluorescence was sometimes observed in conidia germinated for 5 h when the mitochondrial targeting sequence was deleted.

  17. 75 FR 34360 - Listing of Color Additives Exempt From Certification; Bismuth Citrate; Confirmation of Effective...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-17

    ... level of bismuth citrate as a color additive in cosmetics intended for coloring hair on the scalp. DATES... hair on the scalp. FDA gave interested persons until April 26, 2010, to file objections or requests...

  18. Pharmacokinetics of bismuth and ranitidine following single doses of ranitidine bismuth citrate

    PubMed Central

    KOCH, K M; DAVIS, I M; GOODING, A E; YIN, Y

    1996-01-01

    The pharmacokinetics of bismuth and ranitidine derived from ranitidine bismuth citrate given in single oral doses ranging from 200 mg to 1600 mg were evaluated in healthy subjects. Bismuth was only minimally absorbed (<0.5% of the amount dosed) after administration of ranitidine bismuth citrate, and peak plasma concentrations never exceeded 33 ng ml−1 in any subject. Plasma concentrations and urinary recoveries of bismuth at doses up to and including 800 mg were relatively constant and not proportional to dose. Bismuth absorption was increased more than proportionally with the dose at 1600 mg. The pharmacokinetics of ranitidine after administration of ranitidine bismuth citrate were dose-proportional and consistent with previous observations for ranitidine administered alone. Ranitidine bismuth citrate was well-tolerated in single oral doses of up to 1600 mg. PMID:8864318

  19. Myocardial citrate metabolism in control subjects and patients with coronary artery disease.

    PubMed

    Nielsen, T T; Henningsen, P; Bagger, J P; Thomsen, P E; Eyjolfsson, K

    1980-10-01

    A significant release of citrate across the myocardium was demonstrated in twenty-two patients with coronary artery disease (CAD) and in ten control subjects in fasting resting state. In both groups, increasingly negative arterio-coronary sinus (A-Cs) plasma citrate differences correlated positively to arterial plasma free fatty acid (FFA)concentrations and negatively to (A-Cs) differences of plasma glucose. This supports the hypothesis that a citrate inhibition of glycolysis at the site of phosphofructokinase is of regulatory importance for myocardial glucose metabolism, and suggests that FFA supress glucose utilization by the heart in many by this mechanism. The capacity of plasma FFA to increase myocardial citrate release was significantly higher in controls than in patients with CAD, and was found to be positively related to myocardial capacity of oxygen consumption as estimated from the product of heart rate and systolic blood pressure during an exercise tolerance test.

  20. 21 CFR 520.763c - Dithiazanine iodide and piperazine citrate suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... piperazine citrate). (b) Sponsor. See 054628 in § 510.600(c) of this chapter. (c) (d) Conditions of use—(1... for administration by stomach tube, it shall be labeled: “Federal law restricts this drug to use by...

  1. Preventing serpin aggregation: The molecular mechanism of citrate action upon antitrypsin unfolding

    SciTech Connect

    Pearce, Mary C.; Morton, Craig J.; Feil, Susanne C.; Hansen, Guido; Adams, Julian J.; Parker, Michael W.; Bottomley, Stephen P.

    2008-11-21

    The aggregation of antitrypsin into polymers is one of the causes of neonatal hepatitis, cirrhosis, and emphysema. A similar reaction resulting in disease can occur in other human serpins, and collectively they are known as the serpinopathies. One possible therapeutic strategy involves inhibiting the conformational changes involved in antitrypsin aggregation. The citrate ion has previously been shown to prevent antitrypsin aggregation and maintain the protein in an active conformation; its mechanism of action, however, is unknown. Here we demonstrate that the citrate ion prevents the initial misfolding of the native state to a polymerogenic intermediate in a concentration-dependent manner. Furthermore, we have solved the crystal structure of citrate bound to antitrypsin and show that a single citrate molecule binds in a pocket between the A and B beta-sheets, a region known to be important in maintaining antitrypsin stability.

  2. Kinetic studies of the regulation of mitochondrial malate dehydrogenase by citrate.

    PubMed Central

    Gelpí, J L; Dordal, A; Montserrat, J; Mazo, A; Cortés, A

    1992-01-01

    Mitochondrial malate dehydrogenase shows a complex regulation pattern in the presence of citrate. Previously published results indicate that this enzyme is activated by citrate in the NAD(+)----NADH direction and inhibited in the opposite direction. Moreover, high concentrations of L-malate or oxaloacetate produce deviations from the Michaelis-Menten behaviour. Results reported in this paper clearly show that citrate both activates and inhibits mitochondrial malate dehydrogenase in the same direction (NAD(+)----NADH), and in the same reaction medium, depending on substrate concentration. This surprising effect has made it necessary to propose a new kinetic mechanism that extends those previously suggested and allows us to explain both the citrate effect (activating or inhibitory) and the effect of high concentrations of L-malate and oxaloacetate. PMID:1567375

  3. Closed circuit recovery of copper, lead and iron from electronic waste with citrate solutions.

    PubMed

    Torres, Robinson; Lapidus, Gretchen T

    2017-02-01

    An integral closed circuit hydrometallurgical process is presented for base metal recovery from electronic waste. The leaching medium consists of a sodium citrate solution, from which base metals are retrieved by direct electrowinning, and the barren solution is recycled back to the leaching stage. This leaching-electrowinning cycle was repeated four times. The redox properties of the fresh citrate solution, as well as the leach liquors, were characterized by cyclic voltammetry to determine adequate conditions for metal reduction, as well as to limit citrate degradation. The leaching efficiency of electronic waste, employing the same solution after four complete cycles was 71, 83 and 94% for copper, iron and lead, respectively, compared to the original leach with fresh citrate solution.

  4. Citrate influences microbial Fe hydroxide reduction via a dissolution-disaggregation mechanism

    NASA Astrophysics Data System (ADS)

    Braunschweig, Juliane; Klier, Christine; Schröder, Christian; Händel, Matthias; Bosch, Julian; Totsche, Kai U.; Meckenstock, Rainer U.

    2014-08-01

    Microbial reduction of ferric iron is partly dependent on Fe hydroxide particle size: nanosized Fe hydroxides greatly exceed the bioavailability of their counterparts larger than 1 μm. Citrate as a low molecular weight organic acid can likewise stabilize colloidal suspensions against aggregation by electrostatic repulsion but also increase Fe bioavailability by enhancing Fe hydroxide solubility. The aim of this study was to see whether adsorption of citrate onto surfaces of large ferrihydrite aggregates results in the formation of a stable colloidal suspension by electrostatic repulsion and how this effect influences microbial Fe reduction. Furthermore, we wanted to discriminate between citrate-mediated colloid stabilization out of larger aggregates and ferrihydrite dissolution and their influence on microbial Fe hydroxide reduction. Dissolution kinetics of ferrihydrite aggregates induced by different concentrations of citrate and humic acids were compared to microbial reduction kinetics with Geobacter sulfurreducens. Dynamic light scattering results showed the formation of a stable colloidal suspension and colloids with hydrodynamic diameters of 69 (±37) to 165 (± 65) nm for molar citrate:Fe ratios of 0.1 to 0.5 and partial dissolution of ferrihydrite at citrate:Fe ratios ⩾ 0.1. No dissolution or colloid stabilization was detected in the presence of humic acids. Adsorption of citrate, necessary for dissolution, reversed the surface charge and led to electrostatic repulsion between sub-aggregates of ferrihydrite and colloid stabilization when the citrate:Fe ratio was above a critical value (⩽ 0.1). Lower ratios resulted in stronger ferrihydrite aggregation instead of formation of a stable colloidal suspension, owing to neutralization of the positive surface charge. At the same time, microbial ferrihydrite reduction increased from 0.029 to 0.184 mM h-1 indicating that colloids stabilized by citrate addition enhanced microbial Fe reduction. Modelling of

  5. Fingerprinting of sildenafil citrate and tadalafil tablets in pharmaceutical formulations via X-ray fluorescence (XRF) spectrometry.

    PubMed

    Ortiz, Rafael S; Mariotti, Kristiane C; Schwab, Nicolas V; Sabin, Guilherme P; Rocha, Werickson F C; de Castro, Eustáquio V R; Limberger, Renata P; Mayorga, Paulo; Bueno, Maria Izabel M S; Romão, Wanderson

    2012-01-25

    The production of counterfeited drugs is a criminal problem that carries serious risks to public health in the worldwide. In Brazil, Viagra and Cialis are the most counterfeit medicines, being used to inhibit the phosphodiesterase type 5 (PDE-5), treating thus, problems related to erectile dysfunction. X-ray fluorescence (XRF) is a suitable technique to control the quality of new pharmaceutical formulations and distinguish between authentic and counterfeit tablets. XRF has advantageous features like multielemental capability, good detectivity, high precision, short analysis times, and is nondestructive, which makes it suitable to be extended to a great variety of samples. In this work, the inorganic fingerprinting chemical of forty-one commercial samples (Viagra, Cialis, Lazar, Libiden, Maxfil, Plenovit, Potent 75, Rigix, V-50, Vimax and Pramil) and fifty-six counterfeit samples (Viagra and Cialis) were obtained from XRF data. XRF presented an excellent analytical methodology for semi-quantitative determination of active ingredient (in case of sildenafil citrate that presents S in its structure) and excipients such as calcium phosphate, titanium oxide and iron oxide (P, Ca, Ti and Fe). The matrix data were allied to chemometric methods (Principal Component Analysis and Hierarchical Cluster Analysis) to classify the tablets investigated between authentic and counterfeit, grouping the samples into of seven groups: A, B, C, D and E (counterfeit group) and F and G (authentic group).

  6. [THE MODERN PROSPECT FOR CITRATE MIXTURES IN THE TREATMENT OF UROLITHIASIS].

    PubMed

    Chepurov, A K; Pronkin, E A; Bolotov, A D

    2015-01-01

    The authors present a review of literature on the use of litholytic citrate medications for conservative management of urolithiasis. Urate urolithiasis is the most common clinical condition encountered by urologists. Citrate agents, in particular Blemaren, not only may be employed in a conservative therapy of uric acid stones, but can also be successfully used in the treatment of the calcium urolithiasis, i.e. mixed composition stones, which is supported by current international urology guidelines.

  7. The role of citrate and phthalate during Co(II) coprecipitation with calcite

    NASA Astrophysics Data System (ADS)

    Lee, Young J.; Reeder, Richard J.

    2006-05-01

    The influence of citrate and phthalate on Co coprecipitation with calcite was investigated using a combination of batch experiments, Fourier-transform infra-red (FT-IR) spectroscopy, and thermogravimetric analysis (TGA) over a wide range of precipitation rates. Steady-state growth conditions (at constant [Ca], [Co], DIC, and pH) were generally achieved within 3-5 h, after which Co(II) partitioning into calcite was evaluated. Only minor differences are observed in the partition coefficient ( Kd) trends with and without citrate and phthalate as a function of calcite precipitation rate except at very low rates. Slight inhibition of calcite growth is observed in the presence of citrate or phthalate, which can be attributed to adsorption at surface sites. TGA curves for samples coprecipitated with citrate show a significant mass loss between 375 and 550 °C, whereas the weight-loss curves for the Co-phthalate coprecipitates are indistinguishable from those of the organic-free Co coprecipitates. This indicates that citrate is incorporated into calcite during calcite crystallization, whereas phthalate is excluded. FT-IR spectra for the sample with citrate show a broad absorption in the range 3700-3100 cm -1, which is attributable to water molecules coordinated to citrate coprecipitated with calcite. The preferential incorporation of citrate over phthalate likely reflects differences in both aqueous speciation and conformation of the carboxylate groups. This new finding may provide new insight to the factors that control the behavior of macromolecules and their incorporation into the structure of calcium carbonate during biomineralization.

  8. Synergistic iron reduction and citrate dissimilation by Shewanella alga and Aeromonas veronii

    PubMed

    Knight; Caccavo; Wudyka; Blakemore

    1996-10-17

    Two bacterial isolates from Great Bay Estuary, New Hampshire, in co-culture carried out anaerobic dissimilation of citric acid with Fe(III) as the terminal electron acceptor. Neither isolate oxidized citrate with Fe(III) anaerobically in axenic culture. The Fe(III) reducer, Shewanella alga strain BrY, did not grow anaerobically with citrate as an energy source. The citrate utilizer, Aeromonas veronii, did not reduce iron axenically with a variety of electron donors including citrate. The onset of iron reduction by the co-culture occurred after initiation of citrate dissimilation and just prior to initiation of growth by either organism (as measured by viable plate counts). Anaerobic culture growth rates and final cell densities of each bacterial strain were greater in co-culture than in axenic cultures. By 48 h of growth, the co-culture had consumed 27 mM citrate as compared with 12 mM dissimilated by the axenic culture of A. veronii. By 48 h the co-culture produced half as much formate (6 mM) and twice as much acetate (40 mM) as did A. veronii grown axenically (12 mM and 20 mM, respectively). Formate produced from citrate by A. veronii appeared to have supported growth and Fe(III) reduction by S. alga.Although not obligatory, nutrient coupling between these two organisms illustrates that fermentative (A. veronii-type) organisms can convert organic compounds such as citrate to those used as substrates by dissimilatory Fe(III) reducers, including S. alga. This synergism broadens the range of substrates available for iron reduction, stimulates the extent and rate of organic electron donor degradation (and that of iron reduction) and enhances the growth of each participant.

  9. Anaerobic regulation of citrate fermentation by CitAB in Escherichia coli.

    PubMed

    Yamamoto, Kaneyoshi; Matsumoto, Fumika; Oshima, Taku; Fujita, Nobuyuki; Ogasawara, Naotake; Ishihama, Akira

    2008-11-01

    In Escherichia coli, CitB, a cognate response regulator of CitA, specifically bound to the promoter regions for mdh, citA, citC, and exuT. Transcription of these genes was induced by citrate under anaerobic conditions in a CitAB-dependent manner. Taking this together, we conclude that CitAB is the master regulatory system that activates the set of genes involved in citrate fermentation in E. coli.

  10. Clomiphene citrate treatment for late onset hypogonadism: rise and fall

    PubMed Central

    Marconi, Marcelo; Souper, Renato; Hartmann, Jonathan; Alvarez, Matías; Fuentes, Ignacio; Guarda, Francisco J.

    2016-01-01

    ABSTRACT Objective: Previous series have demonstrated that Clomiphene Citrate (CC) is an effective treatment to increase Total Testosterone (TT) in Late Onset Hypogonadism (LOH) patients. However, what happens to TT levels after ending CC treatment is still debatable. The objective of this study is to evaluate TT levels 3 months after the discontinuation of CC in patients with LOH who were previously successfully treated with the same drug. Materials and Methods: Twenty-seven patients with LOH that were successfully treated (achieved TT levels >11nmol/l) with CC 50mgs daily for 50 days were prospectively recruited in our Andrological outpatient clinic. CC was then stopped for 3 months and TT levels were measured at the end of this period. Results: Mean TT level before discontinuation of CC was 22.7±8.1nmol/L (mean±SD). Three months after discontinuation, mean TT level significantly decreased in all patients, 10.2±3.9nmol/l (p<0.01). Twenty-one patients (78%) decreased TT levels under 11nmol/L. Six patients (22%) had TT levels that remained within the normal recommended range (≥11nmol/l). No statistical significant differences were observed between both groups. Conclusion: In the short term LOH does not seem to be a reversible condition in most patients after CC treatment. More studies with longer follow-up are needed to evaluate the kinetics of TT in LOH. PMID:27622282

  11. Pseudohypernatremia secondary to trisodium citrate (Citra-LockTM)

    PubMed Central

    Milliere, Janice; Corriveau, Daryl; Parmar, Malvinder S.

    2016-01-01

    Introduction Hypernatremia is common among hospitalized patients especially in the intensive care units and presents an independent risk factor for mortality. Mild hypernatremia is often asymptomatic but severe hypernatremia causes central nervous system dysfunction with initial non-specific symptoms of encephalopathy that may progress to seizures, coma and death, if left untreated. Severe hypernatremia is a medical emergency and requires emergent medical attention. Materials and methods A haemodialysis patient who arrived for his scheduled haemodialysis treatment had monthly blood work drawn and was reported to have severe hypernatremia with serum sodium concentration of 183 mmol/L. The possibility of technique or laboratory error was considered and systematically evaluated. Results The serum sodium measurement using another analyser showed similar value of 182 mmolL. A repeat serum sodium level on a sample drawn 2 h later showed normal value of 139–140 mmol/L. A step-wise evaluation of the complete procedure from blood collection to analysis of the sample revealed this to be spuriously elevated serum sodium concentration secondary to contamination of the sample during sample collection with trisodium citrate, a catheter-lock solution, commonly used in dialysis units to maintain patency of dialysis catheters. Conclusions Spuriously elevated plasma sodium concentration (pseudohypernatremia) of mild degree is common but severe pseudohypernatremia is rare and the possibility of sample contaminations or laboratory error should be considered. Vigilance is required by both the medical and the laboratory staff to resolve such issues in a timely fashion to avoid unintended consequences. PMID:27346973

  12. 21 CFR 184.1301 - Ferric phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Ferric phosphate. 184.1301 Section 184.1301 Food... GRAS § 184.1301 Ferric phosphate. (a) Ferric phosphate (ferric orthophosphate, iron (III) phosphate, Fe... from one to four molecules of water of hydration. It is prepared by reaction of sodium phosphate...

  13. OsFRDL1 is a citrate transporter required for efficient translocation of iron in rice.

    PubMed

    Yokosho, Kengo; Yamaji, Naoki; Ueno, Daisei; Mitani, Namiki; Ma, Jian Feng

    2009-01-01

    Multidrug and toxic compound extrusion (MATE) transporters represent a large family in plants, but their functions are poorly understood. Here, we report the function of a rice (Oryza sativa) MATE gene (Os03g0216700, OsFRDL1), the closest homolog of barley (Hordeum vulgare) HvAACT1 (aluminum [Al]-activated citrate transporter 1), in terms of metal stress (iron [Fe] deficiency and Al toxicity). This gene was mainly expressed in the roots and the expression level was not affected by either Fe deficiency or Al toxicity. Knockout of this gene resulted in leaf chlorosis, lower leaf Fe concentration, higher accumulation of zinc and manganese concentration in the leaves, and precipitation of Fe in the root's stele. The concentration of citrate and ferric iron in the xylem sap was lower in the knockout line compared to the wild-type rice. Heterologous expression of OsFRDL1 in Xenopus oocytes showed transport activity for citrate. Immunostaining showed that OsFRDL1 was localized at the pericycle cells of the roots. On the other hand, there was no difference in the Al-induced secretion of citrate from the roots between the knockout line and the wild-type rice. Taken together, our results indicate that OsFRDL1 is a citrate transporter localized at the pericycle cells, which is necessary for efficient translocation of Fe to the shoot as a Fe-citrate complex.

  14. Overexpression of Citrus junos mitochondrial citrate synthase gene in Nicotiana benthamiana confers aluminum tolerance.

    PubMed

    Deng, Wei; Luo, Keming; Li, Zhengguo; Yang, Yingwu; Hu, Nan; Wu, Yu

    2009-07-01

    Aluminum (Al) toxicity is one of the major factors that limit plant growth in acid soils. Al-induced release of organic acids into rhizosphere from the root apex has been identified as a major Al-tolerance mechanism in many plant species. In this study, Al tolerance of Yuzu (Citrus Junos Sieb. ex Tanaka) was tested on the basis of root elongation and the results demonstrated that Yuzu was Al tolerant compared with other plant species. Exposure to Al triggered the exudation of citrate from the Yuzu root. Thus, the mechanism of Al tolerance in Yuzu involved an Al-inducible increase in citrate release. Aluminum also elicited an increase of citrate content and increased the expression level of mitochondrial citrate synthase (CjCS) gene and enzyme activity in Yuzu. The CjCS gene was cloned from Yuzu and overexpressed in Nicotiana benthamiana using Agrobacterium tumefaciens-mediated methods. Increased expression level of the CjCS gene and enhanced enzyme activity were observed in transgenic plants compared with the wild-type plants. Root growth experiments showed that transgenic plants have enhanced levels of Al tolerance. The transgenic Nicotiana plants showed increased levels of citrate in roots compared to wild-type plants. The exudation of citrate from roots of the transgenic plants significantly increased when exposed to Al. The results with transgenic plants suggest that overexpression of mitochondrial CS can be a useful tool to achieve Al tolerance.

  15. Assessment of Multiplate® platelet aggregometry using Citrate, Heparin or Hirudin in Rhesus macaques

    PubMed Central

    Dugan, Greg; O’Donnell, Lisa; Hanbury, David B.; Cline, J. Mark; Caudell, David L.

    2016-01-01

    Electrical impedance aggregometry (EIA) has gained popularity for clinical and research applications. Nonhuman primates are used to study disease and drug-related mechanisms that affect hemostasis, therefore normal establishing normal EIA parameters are necessary. The anticoagulants sodium heparin, hirudin and sodium citrate and three agonists, ADP, ASPI, and collagen were evaluated. Whole blood from 12 adult male rhesus macaques was collected to evaluate anticoagulants, sodium heparin, hirudin and sodium citrate using three agonists (ADP, ASPI and collagen), on the Multiplate® 5.0 Analyzer. Platelet function was reported for three parameters: Area under the curve (AUC), aggregation, and aggregation velocity. There was a significant difference in mean AUC between citrate and heparin samples, and citrate and hirudin samples regardless of the agonist used. There was no difference in AUC between heparin and hirudin. ADP-activated samples showed an increase in impedance with hirudin samples compared to citrate. Furthermore heparin and hirudin out-perform citrate as the anticoagulant for EIA in the macaque. Finally, this study demonstrates the utility of the Multiplate® system in this model and provides important insight into anticoagulant choice when using EIA. PMID:25549285

  16. Citrate and celecoxib induce apoptosis and decrease necrosis in synergistic manner in canine mammary tumor cells.

    PubMed

    Vahidi, R; Safi, S; Farsinejad, A; Panahi, N

    2015-10-16

    Celecoxib and citrate have been shown to possess antitumor activity in a variety of cancer cells. However, the antitumor activities of these agents in canine mammary tumors have not been well demonstrated. The aim of our study was to investigate the apoptotic and antiproliferative effects of citrate and celecoxib, individually and in combination, on canine mammary tumor cell line CF41—Mg. MTT assay was performed to determine cell viability, and Annexin—PI test was performed to evaluate apoptosis induction. MTT assay results revealed that compared with the control groups, treatment groups, as both single and combined treatments, showed significant inhibition of tumor growth in a dose—dependent manner. IC50 concentrations of citrate and celecoxib were defined 26mM and 22μM, respectively. In another set of experiment, significant increase in cell apoptosis was observed at IC50 concentrations of citrate and celecoxib after 48h incubation. In spite of that, simultaneous treatment of cells with citrate and celecoxib eventuated with meaningful toxicity augmentation and induction of apoptosis at lower concentrations. Also necrotic cells were decreased by coadministration of the two agents. In conclusion, the present study indicates significant cytotoxic and apoptotic effects of citrate and celecoxib coadministration on CF41—Mg cells, and proposes new strategies for counteracting cancer cells proliferation and overcoming chemo resistance.

  17. Citrate, a Ubiquitous Key Metabolite with Regulatory Function in the CNS.

    PubMed

    Westergaard, Niels; Waagepetersen, Helle S; Belhage, Bo; Schousboe, Arne

    2017-01-05

    Citrate is key constituent of the tricarboxylic acid (TCA) cycle, serves as substrate for fatty acid and sterol biosynthesis, and functions as a key regulator of intermediary energy metabolism. Ursula Sonnewald had initiated studies using for the first time both proton- and (13)C-NMR to investigate metabolic processes in cultured neurons and astrocytes resulting in the important observation that citrate was specifically synthesized in and released from astrocytes in large amounts which is in keeping with the high concentration found in the CSF. The aim of this review is to highlight the possible roles of citrate in physiological and pathophysiological processes in the CNS. An interesting feature of citrate is its ability to chelate Ca(2+), Mg(2+) and Zn(2+)and thereby playing a pivotal role as an endogenous modulator of glutamate receptors and in particular the NMDA subtypes of these receptors in the CNS. Besides its presence in cerebrospinal fluid (CSF) citrate is also found in high amounts in prostate fluid reaching concentrations as high as 180 mM and here Zn(2+) seems also to play an important role, which makes prostate cells interesting for comparison of features of citrate and Zn(2+) between these cells and cells in the CNS.

  18. Citrate synthase encoded by the CIT2 gene of Saccharomyces cerevisiae is peroxisomal.

    PubMed Central

    Lewin, A S; Hines, V; Small, G M

    1990-01-01

    The product of the CIT2 gene has the tripeptide SKL at its carboxyl terminus. This amino acid sequence has been shown to act as a peroxisomal targeting signal in mammalian cells. We examined the subcellular site of this extramitochondrial citrate synthase. Cells of Saccharomyces cerevisiae were grown on oleate medium to induce peroxisome proliferation. A fraction containing membrane-enclosed vesicles and organelles was analyzed by sedimentation on density gradients. In wild-type cells, the major peak of citrate synthase activity was recovered in the mitochondrial fraction, but a second peak of activity cosedimented with peroxisomes. The peroxisomal activity, but not the mitochondrial activity, was inhibited by incubation at pH 8.1, a characteristic of the extramitochondrial citrate synthase encoded by the CIT2 gene. In a strain in which the CIT1 gene encoding mitochondrial citrate synthase had been disrupted, the major peak of citrate synthase activity was peroxisomal, and all of the activity was sensitive to incubation at pH 8.1. Yeast cells bearing a cit2 disruption were unable to mobilize stored lipids and did not form stable peroxisomes in oleate. We conclude that citrate synthase encoded by CIT2 is peroxisomal and participates in the glyoxylate cycle. Images PMID:2181273

  19. SbnG, a citrate synthase in Staphylococcus aureus: A new fold on an old enzyme

    DOE PAGES

    Kobylarz, Marek J.; Grigg, Jason C.; Sheldon, Jessica R.; ...

    2014-10-21

    In response to iron deprivation, Staphylococcus aureus produces staphyloferrin B, a citrate-containing siderophore that delivers iron back to the cell. This bacterium also possesses a second citrate synthase, SbnG, that is necessary for supplying citrate to the staphyloferrin B biosynthetic pathway. In this paper, we present the structure of SbnG bound to the inhibitor calcium and an active site variant in complex with oxaloacetate. The overall fold of SbnG is structurally distinct from TCA cycle citrate synthases yet similar to metal-dependent class II aldolases. Phylogenetic analyses revealed that SbnG forms a separate clade with homologs from other siderophore biosynthetic genemore » clusters and is representative of a metal-independent subgroup in the phosphoenolpyruvate/pyruvate domain superfamily. Finally, a structural superposition of the SbnG active site to TCA cycle citrate synthases and site-directed mutagenesis suggests a case for convergent evolution toward a conserved catalytic mechanism for citrate production.« less

  20. Transport of citrate across renal brush border membrane: effects of dietary acid and alkali loading

    SciTech Connect

    Jenkins, A.D.; Dousa, T.P.; Smith, L.H.

    1985-10-01

    Dietary acid or alkali loading was given to rats by providing 150 mM NH4Cl or 150 mM NaHCO3 in place of drinking water for 6 days; control animals received 150 mM NaCl. After 6 days, the citrate clearance was 0.04 +/- 0.01 ml/min (mean +/- SE) in the acid-loaded group, 0.9 +/- 0.1 ml/min in the control group, and 2.5 +/- 0.2 ml/min in the alkali-loaded group. At the end of the experiment, the rats were killed, and the Na gradient-dependent citrate uptake was measured in brush border membrane (BBM) vesicles prepared from each group. At 0.3 min, the ( UC)citrate uptake was 198 +/- 8 pmol/mg protein (mean +/- SE) in the acid-loaded group, 94 +/- 16 pmol/mg protein in the control group, and 94 +/- 13 pmol/mg protein in the alkali-loaded group. The rate of Na -independent (NaCl in medium replaced by KCl) ( UC)-citrate uptake by BBM vesicles was the same for acid-loaded, control, and alkali-loaded animals. Thus, the increased capacity of the proximal tubular BBM to transport citrate from the tubular lumen into the cell interior may be an important factor that contributes to decreased urinary citrate in the presence of metabolic acidosis induced by chronic dietary acid loading.

  1. Clinical review: Anticoagulation for continuous renal replacement therapy - heparin or citrate?

    PubMed Central

    2011-01-01

    Heparin is the most commonly prescribed anticoagulant for continuous renal replacement therapy. There is, however, increasing evidence questioning its safety, particularly in the critically ill. Heparin mainly confers its anticoagulant effect by binding to antithrombin. Heparin binds to numerous other proteins and cells as well, however, compromising its efficacy and safety. Owing to antithrombin consumption and degradation, and to the binding of heparin to acute phase proteins, and to apoptotic and necrotic cells, critical illness confers heparin resistance. The nonspecific binding of heparin further leads to an unpredictable interference with inflammation pathways, microcirculation and phagocytotic clearance of dead cells, with possible deleterious consequences for patients with sepsis and systemic inflammation. Regional anticoagulation with citrate does not increase the patient's risk of bleeding. The benefits of citrate further include a longer or similar circuit life, and possibly better patient and kidney survival. This needs to be confirmed in larger randomized controlled multicenter trials. The use of citrate might be associated with less inflammation and has useful bio-energetic implications. Citrate can, however, with inadequate use cause metabolic derangements. Full advantages of citrate can only be realized if its risks are well controlled. These observations suggest a greater role for citrate. PMID:21345279

  2. Inositol phosphates in the environment.

    PubMed Central

    Turner, Benjamin L; Papházy, Michael J; Haygarth, Philip M; McKelvie, Ian D

    2002-01-01

    The inositol phosphates are a group of organic phosphorus compounds found widely in the natural environment, but that represent the greatest gap in our understanding of the global phosphorus cycle. They exist as inositols in various states of phosphorylation (bound to between one and six phosphate groups) and isomeric forms (e.g. myo, D-chiro, scyllo, neo), although myo-inositol hexakisphosphate is by far the most prevalent form in nature. In terrestrial environments, inositol phosphates are principally derived from plants and accumulate in soils to become the dominant class of organic phosphorus compounds. Inositol phosphates are also present in large amounts in aquatic environments, where they may contribute to eutrophication. Despite the prevalence of inositol phosphates in the environment, their cycling, mobility and bioavailability are poorly understood. This is largely related to analytical difficulties associated with the extraction, separation and detection of inositol phosphates in environmental samples. This review summarizes the current knowledge of inositol phosphates in the environment and the analytical techniques currently available for their detection in environmental samples. Recent advances in technology, such as the development of suitable chromatographic and capillary electrophoresis separation techniques, should help to elucidate some of the more pertinent questions regarding inositol phosphates in the natural environment. PMID:12028785

  3. Fabrication and cytocompatibility of spherical magnesium ammonium phosphate granules.

    PubMed

    Christel, Theresa; Geffers, Martha; Klammert, Uwe; Nies, Berthold; Höß, Andreas; Groll, Jürgen; Kübler, Alexander C; Gbureck, Uwe

    2014-09-01

    Magnesium phosphate compounds, as for example struvite (MgNH4PO4·6H2O), have comparable characteristics to calcium phosphate bone substitutes, but degrade faster under physiological conditions. In the present work, we used a struvite forming calcium doped magnesium phosphate cement with the formulation Ca0.75Mg2.25(PO4)2 and an ammonium phosphate containing aqueous solution to produce round-shaped granules. For the fabrication of spherical granules, the cement paste was dispersed in a lipophilic liquid and stabilized by surfactants. The granules were characterized with respect to morphology, size distribution, phase composition, compressive strength, biocompatibility and solubility. In general, it was seen that small granules can hardly be produced by means of emulsification, when the raw material is a hydraulic paste, because long setting times promote coalescence of initially small unhardened cement droplets. Here, this problem was solved by using an aqueous solution containing both the secondary (NH4)2HPO4 and primary ammonium phosphates NH4H2PO4 to accelerate the setting reaction. This resulted in granules with 97 wt.% having a size in the range between 200 and 1,000 μm. The novel solution composition doubled the compressive strength of the cement to 37 ± 5 MPa without affecting either the conversion to struvite or the cytocompatibility using human fetal osteoblasts.

  4. How Bonding in Manganous Phosphates Affects their Mn(II)-(31)P Hyperfine Interactions.

    PubMed

    Un, Sun; Bruch, Eduardo M

    2015-11-02

    Manganous phosphates have been postulated to play an important role in cells as antioxidants. In situ Mn(II) electron-nuclear double resonance (ENDOR) spectroscopy has been used to measure their speciation in cells. The analyses of such ENDOR spectra and the quantification of cellular Mn(II) phosphates has been based on comparisons to in vitro model complexes and heuristic modeling. In order to put such analyses on a more physical and theoretical footing, the Mn(II)-(31)P hyperfine interactions of various Mn(II) phosphate complexes have been measured by 95 GHz ENDOR spectroscopy. The dipolar components of these interactions remained relatively constant as a function of pH, esterification, and phosphate chain length, while the isotropic contributions were significantly affected. Counterintuitively, although the manganese-phosphate bonds are weakened by protonation and esterification, they lead to larger isotropic values, indicating higher unpaired-electron spin densities at the phosphorus nuclei. By comparison, extending the phosphate chain with additional phosphate groups lowers the spin density. Density functional theory calculations of model complexes quantitatively reproduced the measured hyperfine couplings and provided detailed insights into how bonding in Mn(II) phosphate complexes modulates the electron-spin polarization and consequently their isotropic hyperfine couplings. These results show that various classes of phosphates can be identified by their ENDOR spectra and provide a theoretical framework for understanding the in situ (31)P ENDOR spectra of cellular Mn(II) complexes.

  5. Light weight phosphate cements

    DOEpatents

    Wagh, Arun S.; Natarajan, Ramkumar,; Kahn, David

    2010-03-09

    A sealant having a specific gravity in the range of from about 0.7 to about 1.6 for heavy oil and/or coal bed methane fields is disclosed. The sealant has a binder including an oxide or hydroxide of Al or of Fe and a phosphoric acid solution. The binder may have MgO or an oxide of Fe and/or an acid phosphate. The binder is present from about 20 to about 50% by weight of the sealant with a lightweight additive present in the range of from about 1 to about 10% by weight of said sealant, a filler, and water sufficient to provide chemically bound water present in the range of from about 9 to about 36% by weight of the sealant when set. A porous ceramic is also disclosed.

  6. Templated, layered manganese phosphate

    DOEpatents

    Thoma, Steven G.; Bonhomme, Francois R.

    2004-08-17

    A new crystalline maganese phosphate composition having an empirical formula: O). The compound was determined to crystallize in the trigonal space group P-3c1 with a=8.8706(4) .ANG., c=26.1580(2) .ANG., and V (volume)=1783 .ANG..sup.3. The structure consists of sheets of corner sharing Mn(II)O.sub.4 and PO.sub.4 tetrahedra with layers of (H.sub.3 NCH.sub.2 CH.sub.2).sub.3 N and water molecules in-between. The pronated (H.sub.3 NCH.sub.2 CH.sub.2).sub.3 N molecules provide charge balancing for the inorganic sheets. A network of hydrogen bonds between water molecules and the inorganic sheets holds the structure together.

  7. Phosphatidylinositol phosphate 5-kinase genes respond to phosphate deficiency for root hair elongation in Arabidopsis thaliana.

    PubMed

    Wada, Yukika; Kusano, Hiroaki; Tsuge, Tomohiko; Aoyama, Takashi

    2015-02-01

    Plants drastically alter their root system architecture to adapt to different underground growth conditions. During phosphate (Pi) deficiency, most plants including Arabidopsis thaliana enhance the development of lateral roots and root hairs, resulting in bushy and hairy roots. To elucidate the signal pathway specific for the root hair elongation response to Pi deficiency, we investigated the expression of type-B phosphatidylinositol phosphate 5-kinase (PIP5K) genes, as a quantitative factor for root hair elongation in Arabidopsis. At young seedling stages, the PIP5K3 and PIP5K4 genes responded to Pi deficiency in steady-state transcript levels via PHR1-binding sequences (P1BSs) in their upstream regions. Both pip5k3 and pip5k4 single mutants, which exhibit short-root-hair phenotypes, remained responsive to Pi deficiency for root hair elongation; however the pip5k3pip5k4 double mutant exhibited shorter root hairs than the single mutants, and lost responsiveness to Pi deficiency at young seedling stages. In the tactical complementation line in which modified PIP5K3 and PIP5K4 genes with base substitutions in their P1BSs were co-introduced into the double mutant, root hairs of young seedlings had normal lengths under Pi-sufficient conditions, but were not responsive to Pi deficiency. From these results, we conclude that a Pi-deficiency signal is transferred to the pathway for root hair elongation via the PIP5K genes.

  8. Potassium citrate decreases urine calcium excretion in patients with hypocitraturic calcium oxalate nephrolithiasis.

    PubMed

    Song, Yan; Hernandez, Natalia; Shoag, Jonathan; Goldfarb, David S; Eisner, Brian H

    2016-04-01

    Two previous studies (<10 patients each) have demonstrated that alkali therapy may reduce urine calcium excretion in patients with calcium oxalate nephrolithiasis. The hypothesized mechanisms are (1) a decrease in bone turnover due to systemic alkalinization by the medications; (2) binding of calcium by citrate in the gastrointestinal tract; (3) direct effects on TRPV5 activity in the distal tubule. We performed a retrospective review of patients on potassium citrate therapy to evaluate the effects of this medication on urinary calcium excretion. A retrospective review was performed of a metabolic stone database at a tertiary care academic hospital. Patients were identified with a history of calcium oxalate nephrolithiasis and hypocitraturia who were on potassium citrate therapy for a minimum of 3 months. 24-h urine composition was assessed prior to the initiation of potassium citrate therapy and after 3 months of therapy. Patients received 30-60 mEq potassium citrate by mouth daily. Inclusion criterion was a change in urine potassium of 20 mEq/day or greater, which suggests compliance with potassium citrate therapy. Paired t test was used to compare therapeutic effect. Twenty-two patients were evaluated. Mean age was 58.8 years (SD 14.0), mean BMI was 29.6 kg/m(2) (SD 5.9), and gender prevalence was 36.4% female:63.6% male. Mean pre-treatment 24-h urine values were as follows: citrate 280.0 mg/day, potassium 58.7 mEq/day, calcium 216.0 mg/day, pH 5.87. Potassium citrate therapy was associated with statistically significant changes in each of these parameters-citrate increased to 548.4 mg/day (p < 0.0001), potassium increased to 94.1 mEq/day (p < 0.0001), calcium decreased to 156.5 mg/day (p = 0.04), pH increased to 6.47 (p = 0.001). Urine sodium excretion was not different pre- and post-therapy (175 mEq/day pre-therapy versus 201 mEq/day post-therapy, p = NS). Urinary calcium excretion decreased by a mean of 60 mg/day on potassium citrate therapy-a nearly 30

  9. Sensitive and selective SERS probe for trivalent chromium detection using citrate attached gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Ye, Yingjie; Liu, Honglin; Yang, Liangbao; Liu, Jinhuai

    2012-09-01

    In this article, we have demonstrated a sensitive and selective surface enhanced Raman spectroscopy (SERS) probe, based on citrate-capped gold nanoparticles (AuNPs), for trivalent chromium (Cr3+) detection. After introducing Tween 20 to a solution of citrate-capped AuNPs, the as-prepared Tween 20/citrate-AuNP probe could recognize Cr3+ at a 50 × 10-9 M level in an aqueous medium at a pH of 6.0. Tween 20 can stabilize the citrate-capped AuNPs against conditions of high ionic strength. Due to the chelation between Cr3+ and citrate ions, AuNPs undergo aggregation. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity through electromagnetic (EM) field enhancements. A detailed mechanism for tremendous SERS intensity change had been discussed. The selectivity of this system toward Cr3+ was 400-fold, remarkably greater than other metal ions.In this article, we have demonstrated a sensitive and selective surface enhanced Raman spectroscopy (SERS) probe, based on citrate-capped gold nanoparticles (AuNPs), for trivalent chromium (Cr3+) detection. After introducing Tween 20 to a solution of citrate-capped AuNPs, the as-prepared Tween 20/citrate-AuNP probe could recognize Cr3+ at a 50 × 10-9 M level in an aqueous medium at a pH of 6.0. Tween 20 can stabilize the citrate-capped AuNPs against conditions of high ionic strength. Due to the chelation between Cr3+ and citrate ions, AuNPs undergo aggregation. As a result, it formed several hot spots and provided a significant enhancement of the Raman signal intensity through electromagnetic (EM) field enhancements. A detailed mechanism for tremendous SERS intensity change had been discussed. The selectivity of this system toward Cr3+ was 400-fold, remarkably greater than other metal ions. Electronic supplementary information (ESI) available: Fig. S1-S5. See DOI: 10.1039/c2nr31985c

  10. Crystallization of calcium phosphate in polyacrylamide hydrogels containing phosphate ions

    NASA Astrophysics Data System (ADS)

    Yokoi, Taishi; Kawashita, Masakazu; Kikuta, Koichi; Ohtsuki, Chikara

    2010-08-01

    Calcium phosphate crystals were formed in polyacrylamide (PAAm) hydrogels containing phosphate ions by diffusion of calcium ions from calcium nitrate (Ca(NO 3) 2) solutions covering the gels. Changes in crystalline phases and crystal morphology of calcium phosphate, and in ion concentrations of the Ca(NO 3) 2 solutions were investigated as a function of reaction time. Single or two coexisting crystalline phases of calcium phosphate, hydroxyapatite (HAp), HAp/dicalcium phosphate dihydrate (DCPD) or octacalcium phosphate (OCP)/DCPD were formed in the gels. HAp crystals are formed near the surface of the gels. The dense HAp layer and HAp/DCPD layer prevented diffusion of calcium ions from the Ca(NO 3) 2 solution, thus formation of calcium phosphate in the gel phase was inhibited. Formation of DCPD was observed to follow the formation of OCP or HAp. The size of the OCP crystals gradually increased with reaction time, while changes in size of HAp crystals were not observed. The reaction time required for DCPD formation depended on the degree of supersaturation with respect to DCPD in the systems. DCPD formed within 1 day under high supersaturation conditions, whereas it formed at 10 days in low supersaturation conditions.

  11. Phosphate nutrition: improving low-phosphate tolerance in crops.

    PubMed

    López-Arredondo, Damar Lizbeth; Leyva-González, Marco Antonio; González-Morales, Sandra Isabel; López-Bucio, José; Herrera-Estrella, Luis

    2014-01-01

    Phosphorus is an essential nutrient that is required for all major developmental processes and reproduction in plants. It is also a major constituent of the fertilizers required to sustain high-yield agriculture. Levels of phosphate--the only form of phosphorus that can be assimilated by plants--are suboptimal in most natural and agricultural ecosystems, and when phosphate is applied as fertilizer in soils, it is rapidly immobilized owing to fixation and microbial activity. Thus, cultivated plants use only approximately 20-30% of the applied phosphate, and the rest is lost, eventually causing water eutrophication. Recent advances in the understanding of mechanisms by which wild and cultivated species adapt to low-phosphate stress and the implementation of alternative bacterial pathways for phosphorus metabolism have started to allow the design of more effective breeding and genetic engineering strategies to produce highly phosphate-efficient crops, optimize fertilizer use, and reach agricultural sustainability with a lower environmental cost. In this review, we outline the current advances in research on the complex network of plant responses to low-phosphorus stress and discuss some strategies used to manipulate genes involved in phosphate uptake, remobilization, and metabolism to develop low-phosphate-tolerant crops, which could help in designing more efficient crops.

  12. Sildenafil citrate attenuates the deleterious effects of elevated ammonia.

    PubMed

    Arafa, Manar H; Atteia, Hebatallah H

    2013-07-01

    Ammonia is a bi-product of protein metabolism in the body. It is able to cross the blood-brain barrier and elevated ammonia levels are toxic to the brain. Rats with hyperammonemia showed impaired learning ability and impaired function of the glutamate-nitric oxide-cyclic guanosine monophosphate (glutamate-NO-cGMP) pathway in the brain. Chronic treatment with sildenafil restored learning ability. We therefore tested the hypothesis that sildenafil has a protective effect on the brains of hyperammonemic rats. Hyperammonemia was induced in male rats by daily intraperitoneal (i.p.) injection of ammonium chloride (100 mg/kg body weight) for 8 weeks. Sildenafil citrate was administered intraperitoneally (10 mg/kg body weight/3 days) for 8 weeks. Treatment with sildenafil resulted in a significant reduction in plasma liver enzymes, lipid profile as well as brain lipid peroxidation and caspase-3 mRNA. Meanwhile, plasma NO as well as cGMP, antioxidants and endothelial nitric oxide synthase (eNOS) gene expression were significantly elevated in the brains of hyperammonemic rats. Our results showed that sildenafil exerts a protective effect on the brain by reversing oxidative stress during hyperammonemia and this could be due to (i) cytoprotective, antioxidant and anti-apoptotic effects (ii) increasing cGMP and enhancing the proper metabolism of fats which could suppress oxygen radical generation and thus preventing oxidative damage in the brain. The exact protective mechanism of sildenafil has to be still investigated and further studies are warranted. Consequently, therapeutic modulation of the NO/cGMP pathway might have important clinical applications to improve brain functions in patients with hyperammonemia or clinical hepatic encephalopathy.

  13. Transport of citrate-coated silver nanoparticles in unsaturated sand.

    PubMed

    Kumahor, Samuel K; Hron, Pavel; Metreveli, George; Schaumann, Gabriele E; Vogel, Hans-Jörg

    2015-12-01

    Chemical factors and physical constraints lead to coupled effects during particle transport in unsaturated porous media. Studies on unsaturated transport as typical for soils are currently scarce. In unsaturated porous media, particle mobility is determined by the existence of an air-water interface in addition to a solid-water interface. To this end, we measured breakthrough curves and retention profiles of citrate-coated Ag nanoparticles in unsaturated sand at two pH values (5 and 9) and three different flow rates corresponding to different water contents with 1 mM KNO3 as background electrolyte. The classical DLVO theory suggests unfavorable deposition conditions at the air-water and solid-water interfaces. The breakthrough curves indicate modification in curve shapes and retardation of nanoparticles compared to inert solute. Retention profiles show sensitivity to flow rate and pH and this ranged from almost no retention for the highest flow rate at pH=9 to almost complete retention for the lowest flow rate at pH=5. Modeling of the breakthrough curves, thus, required coupling two parallel processes: a kinetically controlled attachment process far from equilibrium, responsible for the shape modification, and an equilibrium sorption, responsible for particle retardation. The non-equilibrium process and equilibrium sorption are suggested to relate to the solid-water and air-water interfaces, respectively. This is supported by the DLVO model extended for hydrophobic interactions which suggests reversible attachment, characterized by a secondary minimum (depth 3-5 kT) and a repulsive barrier at the air-water interface. In contrast, the solid-water interface is characterized by a significant repulsive barrier and the absence of a secondary minimum suggesting kinetically controlled and non-equilibrium interaction. This study provides new insights into particle transport in unsaturated porous media and offers a model concept representing the relevant processes.

  14. Testosterone restoration using enclomiphene citrate in men with secondary hypogonadism: a pharmacodynamic and pharmacokinetic study

    PubMed Central

    Wiehle, Ronald; Cunningham, Glenn R; Pitteloud, Nelly; Wike, Jenny; Hsu, Kuang; Fontenot, Gregory K; Rosner, Michele; Dwyer, Andrew; Podolski, Joseph

    2013-01-01

    Objectives To determine the pharmacodynamic profile of serum total testosterone and luteinizing hormone (LH) levels in men with secondary hypogonadism after initial and chronic daily oral doses of enclomiphene citrate vs transdermal testosterone. To determine the effects of daily oral doses of enclomiphene citrate in comparison with transdermal testosterone on other hormones and markers in men with secondary hypogonadism. Patients and Methods This was a randomized, single-blind, two-centre, phase II study to evaluate the effects of three different doses of enclomiphene citrate (6.25, 12.5 and 25 mg) vs transdermal testosterone on 24-h LH and total testosterone in otherwise normal healthy men with secondary hypogonadism. Forty-eight men were enrolled in the trial (the intent-to-treat population), but four men had testosterone levels >350 ng/dL at baseline. Forty-four men completed the study per protocol. All subjects enrolled in this trial had serum total testosterone in the low range (<350 ng/dL) and had low to normal LH (<12 IU/L) on at least two occasions. Total testosterone and LH levels were assessed each hour for 24 h to examine the effects at each of three treatment doses of enclomiphene citrate vs a standard dose (5 g) of transdermal testosterone. In the initial profile, total testosterone and LH were determined in a naïve population after a single initial oral or transdermal treatment (day 1). This was contrasted to that seen after 6 weeks of continuous daily oral or transdermal treatment (day 42). The pharmacokinetics of enclomiphene citrate were assessed in a select subpopulation. Serum samples were obtained over the course of the study to determine the levels of various hormones and lipids. Results After 6 weeks of continuous use, the mean (sd) concentration of total testosterone at day 42 was 604 (160) ng/dL for men taking the highest dose of enclomiphene citrate (enclomiphene citrate, 25 mg daily) and 500 (278) ng in those men treated with transdermal

  15. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other...

  16. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other...

  17. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other...

  18. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other...

  19. 21 CFR 520.823 - Erythromycin phosphate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    .... (a) Specifications. Erythromycin phosphate is the phosphate salt of the antibiotic substance produced by the growth of Streptomyces erythreus or the same antibiotic substance produced by any other...

  20. Effects of sodium phosphate and caffeine loading on repeated-sprint ability.

    PubMed

    Buck, Christopher; Guelfi, Kym; Dawson, Brian; McNaughton, Lars; Wallman, Karen

    2015-01-01

    The effects of sodium phosphate and caffeine supplementation were assessed on repeated-sprint ability. Using a randomised, double-blind, Latin-square design, 12 female, team-sport players participated in four trials: (1) sodium phosphate and caffeine, (2) sodium phosphate and placebo (for caffeine), (3) caffeine and placebo (for sodium phosphate) and (4) placebo (for sodium phosphate and caffeine), with ~21 days separating each trial. After each trial, participants performed a simulated team-game circuit (4 × 15 min quarters) with 6 × 20-m repeated-sprints performed once before (Set 1), at half-time (Set 2), and after end (Set 3). Total sprint times were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 1: P = 0.003; Set 2: d = -0.51; Set 3: P < 0.001; overall: P = 0.020), caffeine (Set 3: P = 0.004; overall: P = 0.033) and sodium phosphate (Set 3: d = -0.67). Furthermore, total sprint times were faster after sodium phosphate supplementation compared with placebo (Set 1: d = -0.52; Set 3: d = -0.58). Best sprint results were faster after sodium phosphate and caffeine supplementation compared with placebo (Set 3: P = 0.007, d = -0.90) and caffeine (Set 3: P = 0.024, d = -0.73). Best sprint times were also faster after sodium phosphate supplementation compared with placebo (d = -0.54 to -0.61 for all sets). Sodium phosphate and combined sodium phosphate and caffeine loading improved repeated-sprint ability.

  1. Injectable and rapid-setting calcium phosphate bone cement with dicalcium phosphate dihydrate.

    PubMed

    Burguera, Elena F; Xu, Hockin H K; Weir, Michael D

    2006-04-01

    Calcium phosphate cement (CPC) sets in situ with intimate adaptation to the contours of defect surfaces, and forms an implant having a structure and composition similar to hydroxyapatite, the putative mineral in teeth and bones. The objective of the present study was to develop an injectable CPC using dicalcium phosphate dihydrate (DCPD) with a high solubility for rapid setting. Two agents were incorporated to impart injectability and fast-hardening to the cement: a hardening accelerator (sodium phosphate) and a gelling agent (hydroxypropyl methylcellulose, HPMC). The cement with DCPD was designated as CPC(D), and the conventional cement was referred to as CPC(A). Using water without sodium phosphate, CPC(A) had a setting time of 82 +/- 6 min. In contrast, CPC(D) exhibited rapid setting with a time of 17 +/- 1 min. At 0.2 mol/L sodium phosphate, setting time for CPC(D) was 15 +/- 1 min, significantly faster than 40 +/- 2 min for CPC(A) (Tukey's at 0.95). Sodium phosphate decreased the paste injectability (measured as the paste mass extruded from the syringe divided by the original paste mass inside the syringe). However, the addition of HPMC dramatically increased the paste injectability. For CPC(D), the injectability was increased from 65% +/- 12% without HPMC to 98% +/- 1% with 1% HPMC. Injectability of CPC(A) was also doubled to 99% +/- 1%. The injectable and rapid-setting CPC(D) possessed flexural strength and elastic modulus values overlapping the reported values for sintered porous hydroxyapatite implants and cancellous bone. In summary, the rapid setting and relatively high strength and elastic modulus of CPC(D) should help the graft to quickly attain strength and geometrical integrity within a short period of time postoperatively. Furthermore, the injectability of CPC(D) may have potential for procedures involving defects with limited accessibility or narrow cavities, when there is a need for precise placement of the paste, and when using minimally invasive

  2. Protective effects of sildenafil citrate administration on cisplatin-induced ovarian damage in rats.

    PubMed

    Taskin, Mine Islimye; Yay, Arzu; Adali, Ertan; Balcioglu, Esra; Inceboz, Umit

    2015-04-01

    The aim of this study is to evaluate the effects of sildenafil citrate on cisplatin-induced ovarian toxicity. Thirty-two female rats were divided into four groups. Group 1: saline control; group 2: cisplatin; group 3: sildenafil citrate; and group 4: cisplatin plus sildenafil citrate group. In groups 2 and 4, the rats were injected with 5 mg/kg cisplatin intraperitoneally (i.p.). In groups 3 and 4, the rats were injected with 1.4 mg/kg sildenafil citrate i.p. The ovaries were removed two weeks later in all groups. Histopathologic examination, follicle counting and classification were performed. The expression of anti-Müllerian hormone (AMH) was detected immunohistochemically in the ovarian tissues. Sildenafil alleviated cisplatin-induced histopathological changes in the ovarian tissue. Primordial, secondary and tertiary follicles were diminished in group 2 compared with group 1 (p < 0.05). Pretreatment with sildenafil citrate preserved primordial follicle count in group 4 compared with group 2, and the difference was statistically significant (p < 0.05). According to our results, immunoreactivity intensity of AMH was lower in group 2 compared with group 1 (92.4 ± 3.97 versus 88.8 ± 1.77) but not significantly, whereas immunoreactivity intensity of AMH was higher in group 4 compared with group 2 (88.8 ± 1.77 versus 94.1 ± 2.36; p < 0.05). Our results demonstrated that pretreatment with sildenafil citrate is beneficial for protecting the ovaries from cisplatin-induced damage. Sildenafil citrate can be a choice for fertility preservation.

  3. Localization of the calcium-regulated citrate transport process in proximal tubule cells.

    PubMed

    Hering-Smith, Kathleen S; Mao, Weibo; Schiro, Faith R; Coleman-Barnett, Joycelynn; Pajor, Ana M; Hamm, L Lee

    2014-06-01

    Urinary citrate is an important inhibitor of calcium-stone formation. Most of the citrate reabsorption in the proximal tubule is thought to occur via a dicarboxylate transporter NaDC1 located in the apical membrane. OK cells, an established opossum kidney proximal tubule cell line, transport citrate but the characteristics change with extracellular calcium such that low calcium solutions stimulate total citrate transport as well as increase the apparent affinity for transport. The present studies address several fundamental properties of this novel process: the polarity of the transport process, the location of the calcium-sensitivity and whether NaDC1 is present in OK cells. OK cells grown on permeable supports exhibited apical >basolateral citrate transport. Apical transport of both citrate and succinate was sensitive to extracellular calcium whereas basolateral transport was not. Apical calcium, rather than basolateral, was the predominant determinant of changes in transport. Also 2,3-dimethylsuccinate, previously identified as an inhibitor of basolateral dicarboxylate transport, inhibited apical citrate uptake. Although the calcium-sensitive transport process in OK cells is functionally not typical NaDC1, NaDC1 is present in OK cells by Western blot and PCR. By immunolocalization studies, NaDC1 was predominantly located in discrete apical membrane or subapical areas. However, by biotinylation, apical NaDC1 decreases in the apical membrane with lowering calcium. In sum, OK cells express a calcium-sensitive/regulated dicarboxylate process at the apical membrane which responds to variations in apical calcium. Despite the functional differences of this process compared to NaDC1, NaDC1 is present in these cells, but predominantly in subapical vesicles.

  4. Differential modulation of citrate synthesis and release by fatty acids in perfused working rat hearts.

    PubMed

    Vincent, Genevieve; Bouchard, Bertrand; Khairallah, Maya; Des Rosiers, Christine

    2004-01-01

    The objective of this study was to test the effect of increasing fatty acid concentrations on substrate fluxes through pathways leading to citrate synthesis and release in the heart. This was accomplished using semirecirculating work-performing rat hearts perfused with substrate mixtures mimicking the in situ milieu (5.5 mM glucose, 8 nM insulin, 1 mM lactate, 0.2 mM pyruvate, and 0.4 mM oleate-albumin) and 13C methods. Raising the fatty acid concentration from 0.4 to 1 mM with long-chain oleate or medium-chain octanoate resulted in a lowering ( approximately 20%) of cardiac output and efficiency with unaltered O2 consumption. At the metabolic level, beyond the expected effects of high fatty acid levels on the contribution of pyruvate decarboxylation (reduced >3-fold) and beta-oxidation (enhanced approximately 3-fold) to citrate synthesis, there was also a 2.4-fold lowering of anaplerotic pyruvate carboxylation. Despite the dual inhibitory effect of high fatty acids on pyruvate decarboxylation and carboxylation, tissue citrate levels were twofold higher, but citrate release rates remained unchanged at 11-14 nmol/min, representing <0.5% of citric acid cycle flux. A similar trend was observed for most metabolic parameters after oleate or octanoate addition. Together, these results emphasize a differential modulation of anaplerotic pyruvate carboxylation and citrate release in the heart by fatty acids. We interpret the lack of effects of high fatty acid concentrations on citrate release rates as suggesting that, under physiological conditions, this process is maximal, probably limited by the activity of its mitochondrial or plasma membrane transporter. Limited citrate release at high fatty acid concentrations may have important consequences for the heart's fuel metabolism and function.

  5. The Aqueous Complexation of Thorium with Citrate under Neutral to Basic Conditions

    SciTech Connect

    Felmy, Andrew R; Cho, Herman M; Dixon, David A; Xia, Yuanxian; Hess, Nancy J; Wang, Zheming

    2006-04-20

    The aqueous complexation of thorium with citrate was investigated under neutral to basic conditions and over a broad range of ionic strengths. The solubility data for ThO2(am) as a function of citrate concentration indicate the presence of stable species with citrate-to-metal ratios of between two to three. The dependence of the ThO2(am) solubilities on hydrogen ion concentration can also be readily explained by the classical assumption of hydrolysis of the central Th(IV) ion to form mixed thorium-hydroxide-citrate complexes. 13C NMR spectra of the species in solution confirm that the citrate-to-metal ratio of the species in solution is between two and three and show that the citrate attaches to the metal in a bidentate fashion through oxygens on the -carboxylate and -alkoxyl groups, rather than through the carboxylate groups. The 13C NMR spectra, as well as a density functional theory (DFT) electronic structure study of the presumptive complexes, suggests that the associated α-hydroxyl proton can be displaced during complex formation. These findings indicate an alternative explanation for the observed changes in solubility as a function of hydrogen ion concentration, the displacement of protons from the citrate alkoxyl groups via metal binding. Removal of protons from the alkoxyl groups or hydrolysis of the central Th(IV) cannot be distinguished by thermodynamic measurements, however the species with the α-hydroxyl proton removed (i.e., ThOH(Cit)25- and Th(Cit)38-) would appear to better represent the microscopic binding. Apparent equilibrium constants for the solution phase reactions of these species and the hydrous thorium oxide have been calculated as a function of ionic strength.

  6. Arsenic uptake by aquatic macrophyte Spirodela polyrhiza L.: interactions with phosphate and iron.

    PubMed

    Rahman, M Azizur; Hasegawa, H; Ueda, K; Maki, T; Rahman, M Mahfuzur

    2008-12-30

    The uptake of arsenate (As(V)) and dimethylarsinic acid (DMAA) by aquatic macrophyte Spirodela polyrhiza L. was investigated to determine the influence of arsenic interaction with PO4(3-) and Fe ions. Plants were grown hydroponically on standard Murashige and Skoog (MS) culture solutions. Arsenic concentrations in Fe-oxide (Fe-plaque) on plant surfaces were determined by citrate-bicarbonate-ethylenediaminetetraacetic acid (CBE) technique. S. polyrhiza L. accumulated 51-fold arsenic from arsenate solution compared to that from DMAA solution with initial concentrations of 4.0 and 0.02microM of arsenic and phosphate, respectively. The arsenate uptake was negatively (p<0.001) correlated with phosphate uptake and positively (p<0.05) correlated with iron uptake. About 56% of the total arsenic was accumulated into the plant tissues while 44% was adsorbed on Fe-plaque (CBE-extract), when the plants were grown on arsenate solution. The DMAA uptake into the plant was neither affected by the phosphate concentrations nor correlated (p>0.05) with iron accumulation. The results suggest that adsorption of arsenate on Fe-plaque of the surface of S. polyrhiza L. contributes to the arsenic uptake significantly. Thus, arsenate uptake in S. polyrhiza L. occurred through the phosphate uptake pathway and by physico-chemical adsorption on Fe-plaques of plant surfaces as well. The S. polyrhiza L. uses different mechanisms for DMAA uptake.

  7. Effects of phosphate buffer in parenteral drugs on particle formation from glass vials.

    PubMed

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2013-01-01

    The characteristics of inorganic particles generated in glass vials filled with phosphate buffer solutions were investigated. During storage, particles were visually detected in the phosphate buffer solution in particular glass vials which pass compendial tests of containers for injectable drugs. These particles were considered to be different from ordinal glass delamination, which has been reported in a number of papers because the particles were mainly composed of Al, P and O, but not Si. The formation of the particles accelerated at higher storage temperatures. Among the surface treatments tested for the glass vials, sulfur treatment showed a protective effect on the particle formation in the vials, whereas the SiO(2) coating did not have any protective effects. It was found that the elution ratio of Al and Si in the solution stored in the glass vials after the heating was similar to the ratio of Al and Si in borosilicate glass. However, the Al concentration decreased during storage (5°C, 6 months), and consequently, particle formation was observed in the solution. Adding citrate, which is a chelating agent for Al, effectively suppressed the particle formation in the heated solution. When 50 ppb and higher concentrations of Al ion were added to the phosphate buffer solution, the formation of white particles containing Al, P and O was detected. It is suggested that a phosphate buffer solution in a borosilicate glass vial has the ability to form particles due to interactions with the Al that is eluted from the glass during storage.

  8. Optimalization of Poly(neutral red) Coated-wire Electrode for Determination of Citrate in Soft Drinks

    PubMed Central

    Broncová, Gabriela; Shishkanova, Tatiana V.; Krondak, Martin; Volf, Radko; Král, Vladimír

    2008-01-01

    This report presents an optimization of potentiometric measurements with citrate-selective electropolymerized poly(neutral red) electrodes. The optimal background electrolyte for these measurements is a TRIS buffer with nitrate at pH 8.5. The electrodes described here exhibit stable and reproducible near-Nernstian response to citrates with a low detection limit of 6 × 10-6 M. Electrodes polymerized from sulfuric acid and acetonitrile are compared in detail. Simple and sensitive method for quantification of citrate in real-life samples by potentiometry with poly(neutral red) electrodes are presented. Data from potentiometric measurements of citrate are compared with capillary electrophoresis. PMID:27879724

  9. Catabolite repression of the citrate fermentation genes in Klebsiella pneumoniae: evidence for involvement of the cyclic AMP receptor protein.

    PubMed

    Meyer, M; Dimroth, P; Bott, M

    2001-09-01

    Klebsiella pneumoniae is able to grow anaerobically with citrate as a sole carbon and energy source by a fermentative pathway involving the Na(+)-dependent citrate carrier CitS, citrate lyase, and oxaloacetate decarboxylase. The corresponding genes are organized in the divergent citC and citS operons, whose expression is strictly dependent on the citrate-sensing CitA-CitB two-component system. Evidence is provided here that the citrate fermentation genes are subject to catabolite repression, since anaerobic cultivation with a mixture of citrate and glucose or citrate and gluconate resulted in diauxic growth. Glucose, gluconate, and also glycerol decreased the expression of a chromosomal citS-lacZ fusion by 60 to 75%, whereas a direct inhibition of the citrate fermentation enzymes was not observed. The purified cyclic AMP (cAMP) receptor protein (CRP) of K. pneumoniae bound to two sites in the citC-citS intergenic region, which were centered at position -41.5 upstream of the citC and citS transcriptional start sites. Binding was apparently stimulated by the response regulator CitB. These data indicate that catabolite repression of the citrate fermentation genes is exerted by CRP and that in the absence of repressing carbon sources the cAMP-CRP complex serves to enhance the basal, CitB-dependent transcription level.

  10. Generation of circularly permuted fluorescent-protein-based indicators for in vitro and in vivo detection of citrate.

    PubMed

    Honda, Yuki; Kirimura, Kohtaro

    2013-01-01

    Indicators for citrate, particularly those applicable to its in vivo detection and quantitation, have attracted much interest in both biochemical studies and industrial applications since citrate is a key metabolic intermediate playing important roles in living cells. We generated novel fluorescence indicators for citrate by fusing the circularly permuted fluorescent protein (cpFP) and the periplasmic domain of the bacterial histidine kinase CitA, which can bind to citrate with high specificity. The ratiometric fluorescent signal change was observed with one of these cpFP-based indicators, named CF98: upon addition of citrate, the excitation peak at 504 nm increased proportionally to the decrease in the peak at 413 nm, suitable for build-in quantitative estimation of the binding compound. We confirmed that CF98 can be used for detecting citrate in vitro at millimolar levels in the range of 0.1 to 50 mM with high selectivity; even in the presence of other organic acids such as isocitrate and malate, the fluorescence intensity of CF98 remains unaffected. We finally demonstrated the in vivo applicability of CF98 to estimation of the intracellular citrate concentration in Escherichia coli co-expressing the genes encoding CF98 and the citrate carrier CitT. The novel indicator CF98 can be a specific and simple detection tool for citrate in vitro and a non-invasive tool for real-time estimation of intracellular concentrations of the compound in vivo.

  11. Stabilizing effect of citrate buffer on the photolysis of riboflavin in aqueous solution

    PubMed Central

    Ahmad, Iqbal; Sheraz, Muhammad Ali; Ahmed, Sofia; Kazi, Sadia Hafeez; Mirza, Tania; Aminuddin, Mohammad

    2011-01-01

    In the present investigation the photolysis of riboflavin (RF) in the presence of citrate species at pH 4.0–7.0 has been studied. A specific multicomponent spectrophotometric method has been used to assay RF in the presence of photoproducts during the reactions. The overall first-order rate constants (kobs) for the photolysis of RF range from 0.42 to 1.08×10–2 min−1 in the region. The values of kobs have been found to decrease with an increase in citrate concentration indicating an inhibitory effect of these species on the rate of reaction. The second-order rate constants for the interaction of RF with total citrate species causing inhibition range from 1.79 to 5.65×10–3 M−1 min−1 at pH 4.0–7.0. The log k–pH profiles for the reactions at 0.2–1.0 M citrate concentration show a gradual decrease in kobs and the value at 1.0 M is more than half compared to that of k0, i.e., in the absence of buffer, at pH 5.0. Divalent citrate ions cause a decrease in RF fluorescence due to the quenching of the excited singlet state resulting in a decrease in the rate of reaction and consequently leading to the stabilization of RF solutions. The greater quenching of fluorescence at pH 4.0 compared to that of 7.0 is in accordance with the greater concentration of divalent citrate ions (99.6%) at that pH. The trivalent citrate ions exert a greater inhibitory effect on the rate of RF photolysis compared to that of the divalent citrate ions probably as a result of excited triplet state quenching. The values of second-order rate constants for the interaction of divalent and trivalent citrate ions are 0.44×10–2 and 1.06×10–3 M–1 min–1, respectively, indicating that the trivalent ions exert a greater stabilizing effect, compared to the divalent ions, on RF solutions. PMID:25755977

  12. Inhibition of calcium oxalate monohydrate growth by citrate and the effect of the background electrolyte

    NASA Astrophysics Data System (ADS)

    Weaver, Matthew L.; Qiu, S. Roger; Hoyer, John R.; Casey, William H.; Nancollas, George H.; De Yoreo, James J.

    2007-08-01

    Pathological mineralization is a common phenomenon in broad range of plants and animals. In humans, kidney stone formation is a well-known example that afflicts approximately 10% of the population. Of the various calcium salt phases that comprise human kidney stones, the primary component is calcium oxalate monohydrate (COM). Citrate, a naturally occurring molecule in the urinary system and a common therapeutic agent for treating stone disease, is a known inhibitor of COM. Understanding the physical mechanisms of citrate inhibition requires quantification of the effects of both background electrolytes and citrate on COM step kinetics. Here we report the results of an in situ AFM study of these effects, in which we measure the effect of the electrolytes LiCl, NaCl, KCl, RbCl, and CsCl, and the dependence of step speed on citrate concentration for a range of COM supersaturations. We find that varying the background electrolyte results in significant differences in the measured step speeds and in step morphology, with KCl clearly producing the smallest impact and NaCl the largest. The kinetic coefficient for the former is nearly three times larger than for the latter, while the steps change from smooth to highly serrated when KCl is changed to NaCl. The results on the dependence of step speed on citrate concentration show that citrate produces a dead zone whose width increases with citrate concentration as well as a continual reduction in kinetic coefficient with increasing citrate level. We relate these results to a molecular-scale view of inhibition that invokes a combination of kink blocking and step pinning. Furthermore, we demonstrate that the classic step-pinning model of Cabrera and Vermilyea (C-V model) does an excellent job of predicting the effect of citrate on COM step kinetics provided the model is reformulated to more realistically account for impurity adsorption, include an expression for the Gibbs-Thomson effect that is correct for all supersaturations

  13. A water setting tetracalcium phosphate-dicalcium phosphate dihydrate cement.

    PubMed

    Burguera, E F; Guitián, F; Chow, L C

    2004-11-01

    The development of a calcium phosphate cement, comprising tetracalcium phosphate (TTCP) and dicalcium phosphate dihydrate (DCPD), that hardens in 14 min with water as the liquid or 6 min with a 0.25 mol/L sodium phosphate solution as the liquid, without using hydroxyapatite (HA) seeds as setting accelerator, is reported. It was postulated that reduction in porosity would increase cement strength. Thus, the effects of applied pressure during the initial stages of the cement setting reaction on cement strength and porosity were studied. The cement powder comprised an equimolar mixture of TTCP and DCPD (median particle sizes 17 and 1.7 microm, respectively). Compressive strengths (CS) of samples prepared with distilled water were 47.6 +/- 2.4 MPa, 50.7 +/- 4.2 MPa, and 52.9 +/- 4.7 MPa at applied pressures of 5 MPa, 15 MPa, and 25 MPa, respectively. When phosphate solution was used, the CS values obtained were 41.5 +/- 2.3 MPa, 37.9 +/- 1.7 MPa, and 38.1 +/- 2.3 MPa at the same pressure levels. Statistical analysis of the results showed that pressure produced an improvement in CS when water was used as liquid but not when the phosphate solution was used. Compared to previously reported TTCP-DCPD cements, the greater CS values and shorter setting times together with a simplified formulation should make the present TTCP-DCPD cement a useful material as a bone substitute for clinical applications.

  14. Films based on neutralized chitosan citrate as innovative composition for cosmetic application.

    PubMed

    Libio, Illen C; Demori, Renan; Ferrão, Marco F; Lionzo, Maria I Z; da Silveira, Nádya P

    2016-10-01

    In this work, citrate and acetate buffers, were investigated as neutralizers to chitosan salts in order to provide biocompatible and stable films. To choose the appropriate film composition for this study, neutralized chitosan citrate and acetate films, with and without the plasticizer glycerol, were prepared and characterized by thickness, moisture content, degree of swelling, total soluble matter in acid medium, simultaneous thermal analysis and differential scanning calorimetry. Chitosan films neutralized in citrate buffer showed greater physical integrity resulted from greater thicknesses, lower moisture absorbance, lower tendency to solubility in the acid medium, and better swelling capacities. According to thermal analyses, these films had higher interaction with water which is considered an important feature for cosmetic application. Since the composition prepared in citrate buffer without glycerol was considered to present better physical integrity, it was applied to investigate hyaluronic acid release in a skin model. Skins treated with those films, with or without hyaluronic acid, show stratum corneum desquamation and hydration within 10min. The results suggest that the neutralized chitosan citrate film prepared without glycerol promotes a cosmetic effect for skin exfoliation in the presence or absence of hyaluronic acid.

  15. Study on the Antimicrobial Properties of Citrate-Based Biodegradable Polymers

    PubMed Central

    Su, Lee-Chun; Xie, Zhiwei; Zhang, Yi; Nguyen, Kytai Truong; Yang, Jian

    2014-01-01

    Citrate-based polymers possess unique advantages for various biomedical applications since citric acid is a natural metabolism product, which is biocompatible and antimicrobial. In polymer synthesis, citric acid also provides multiple functional groups to control the crosslinking of polymers and active binding sites for further conjugation of biomolecules. Our group recently developed a number of citrate-based polymers for various biomedical applications by taking advantage of their controllable chemical, mechanical, and biological characteristics. In this study, various citric acid derived biodegradable polymers were synthesized and investigated for their physicochemical and antimicrobial properties. Results indicate that citric acid derived polymers reduced bacterial proliferation to different degrees based on their chemical composition. Among the studied polymers, poly(octamethylene citrate) showed ~70–80% suppression to microbe proliferation, owing to its relatively higher ratio of citric acid contents. Crosslinked urethane-doped polyester elastomers and biodegradable photoluminescent polymers also exhibited significant bacteria reduction of ~20 and ~50% for Staphylococcus aureus and Escherichia coli, respectively. Thus, the intrinsic antibacterial properties in citrate-based polymers enable them to inhibit bacteria growth without incorporation of antibiotics, silver nanoparticles, and other traditional bacteria-killing agents suggesting that the citrate-based polymers are unique beneficial materials for wound dressing, tissue engineering, and other potential medical applications where antimicrobial property is desired. PMID:25023605

  16. Effect of topically applied sildenafil citrate on wound healing: experimental study.

    PubMed

    Gürsoy, Koray; Oruç, Melike; Kankaya, Yüksel; Ulusoy, Mustafa Gürhan; Koçer, Uğur; Kankaya, Duygu; Gürsoy, Reyhan Neslihan; Çevik, Özge; Öğüş, Elmas; Fidanci, Vildan

    2014-08-16

    Wound healing is a complex process that necessitates organization of different cell types and several signalling molecules. The aim of this study is to evaluate the effect of different concentrations of sildenafil citrate, which decreases cGMP degradation, on wound healing by secondary intention.This study was performed using 25 Sprague Dawley rats weighing 200-250 grams. 4 dorsal defects were created. Four different treatment modalities which were 1% and 5% sildenafil citrate gel prepared with carbopol, pure carbopol gel without any drug in it and 0,9% NaCl solution; were applied to each lesion of the same rat. Randomly selected five rats (25 rats in total) were sacrificed on 3rd, 5th, 7th, 10th, and 14th days; and the effect of each modality was evaluated by means of defect area measurement, histopathological examination and measurement of tissue hydroxyproline levels.Sildenafil citrate gel application decreased the defect areas in a dose independent manner starting from 3rd day and dose dependent manner after 7th day. By means of vascularization, sildenafil citrate increased vascularity starting from 3rd day. The strength of acute inflammation was superior in sildenafil groups starting from 5th day; and the amount and maturation of granulation in the wound bed, as well as the strength of chronic inflammation were superior in defects treated with sildenafil citrate as early as 7th day.

  17. The FRD3 citrate effluxer promotes iron nutrition between symplastically disconnected tissues throughout Arabidopsis development.

    PubMed

    Roschzttardtz, Hannetz; Séguéla-Arnaud, Mathilde; Briat, Jean-François; Vert, Grégory; Curie, Catherine

    2011-07-01

    We present data supporting a general role for FERRIC REDICTASE DEFECTIVE3 (FRD3), an efflux transporter of the efficient iron chelator citrate, in maintaining iron homeostasis throughout plant development. In addition to its well-known expression in root, we show that FRD3 is strongly expressed in Arabidopsis thaliana seed and flower. Consistently, frd3 loss-of-function mutants are defective in early germination and are almost completely sterile, both defects being rescued by iron and/or citrate supply. The frd3 fertility defect is caused by pollen abortion and is associated with the male gametophytic expression of FRD3. Iron imaging shows the presence of important deposits of iron on the surface of aborted pollen grains. This points to a role for FRD3 and citrate in proper iron nutrition of embryo and pollen. Based on the findings that iron acquisition in embryo, leaf, and pollen depends on FRD3, we propose that FRD3 mediated-citrate release in the apoplastic space represents an important process by which efficient iron nutrition is achieved between adjacent tissues lacking symplastic connections. These results reveal a physiological role for citrate in the apoplastic transport of iron throughout development, and provide a general model for multicellular organisms in the cell-to-cell transport of iron involving extracellular circulation.

  18. Enhancing radium solubilization in soils by citrate, EDTA, and EDDS chelating amendments.

    PubMed

    Prieto, C; Lozano, J C; Blanco Rodríguez, P; Tomé, F Vera

    2013-04-15

    The effect of three chelating agents (citrate, EDTA, and EDDS) on the solubilization of radium from a granitic soil was studied systematically, considering different soil pH values, chelating agent concentrations, and leaching times. For all the chelating agents tested, the amount of radium leached proved to be strongly dependent on the pH of the substrate: only for acidic conditions did the amount of radium released increase significantly relative to the controls. Under the best conditions, the radium released from the amended soil was greater by factors of 20 in the case of citrate, 18 for EDTA, and 14 for EDDS. The greatest improvement in the release of radium was obtained for the citrate amendment at the highest concentration tested (50 mmol kg(-1)). A slightly lower amount of radium was leached with EDTA at 5 mmol kg(-1) soil, but the solubilization over time was very different from that observed with citrate or EDDS. With EDTA, a maximum in radium leaching was reached on the first day after amendment, while with citrate, the maximum was attained on the fourth day. With EDDS, radium leaching increased slightly but steadily with time (until the sixth day), but the net effect for the period tested was the lowest of the three reagents.

  19. Study on the Antimicrobial Properties of Citrate-Based Biodegradable Polymers.

    PubMed

    Su, Lee-Chun; Xie, Zhiwei; Zhang, Yi; Nguyen, Kytai Truong; Yang, Jian

    2014-01-01

    Citrate-based polymers possess unique advantages for various biomedical applications since citric acid is a natural metabolism product, which is biocompatible and antimicrobial. In polymer synthesis, citric acid also provides multiple functional groups to control the crosslinking of polymers and active binding sites for further conjugation of biomolecules. Our group recently developed a number of citrate-based polymers for various biomedical applications by taking advantage of their controllable chemical, mechanical, and biological characteristics. In this study, various citric acid derived biodegradable polymers were synthesized and investigated for their physicochemical and antimicrobial properties. Results indicate that citric acid derived polymers reduced bacterial proliferation to different degrees based on their chemical composition. Among the studied polymers, poly(octamethylene citrate) showed ~70-80% suppression to microbe proliferation, owing to its relatively higher ratio of citric acid contents. Crosslinked urethane-doped polyester elastomers and biodegradable photoluminescent polymers also exhibited significant bacteria reduction of ~20 and ~50% for Staphylococcus aureus and Escherichia coli, respectively. Thus, the intrinsic antibacterial properties in citrate-based polymers enable them to inhibit bacteria growth without incorporation of antibiotics, silver nanoparticles, and other traditional bacteria-killing agents suggesting that the citrate-based polymers are unique beneficial materials for wound dressing, tissue engineering, and other potential medical applications where antimicrobial property is desired.

  20. Radiolabeled porphyrin versus gallium-67 citrate for the detection of human melanoma in athymic mice

    SciTech Connect

    Maric, N.; Chan, S. Ming; Hoffer, P.B.; Duray, P.

    1987-01-01

    We performed the biodistribution and imaging studies of /sup 111/In and /sup 67/Ga labeled tetra(4-N-methylpyridyl) porphine, (T4NMPYP), and compared it to that of /sup 67/Ga citrate in athymic mice bearing a human melanoma xenograft. The biodistribution results of both /sup 111/In and /sup 67/Ga labeled T4NMPYP (3, 6, 24, and 48 hours) were similar but differed from that of /sup 67/Ga citrate (48 hours). The optimum tumor uptake of both radiolabeled porphyrins was at 6 hours postinjection and was lower than the tumor uptake of /sup 67/Ga citrate at 48 hours postinjection. Kidney was the only organ showing higher uptake of radiolabeled porphyrin compared to that of /sup 67/Ga citrate. The imaging studies performed with /sup 111/In T4NMPYP and /sup 67/Ga citrate correspond to the biodistribution results. Osteomyelitis present in one mouse showed good localization of /sup 111/In T4NMPYP. 15 refs., 3 figs., 5 tabs.

  1. Recent advances in phosphate biosensors.

    PubMed

    Upadhyay, Lata Sheo Bachan; Verma, Nishant

    2015-07-01

    A number of biosensors have been developed for phosphate analysis particularly, concerning its negative impact within the environmental and biological systems. Enzymatic biosensors comprising either a single or multiple enzymatic system have been extensively used for the direct and indirect analysis of phosphate ions. Furthermore, some non-enzymatic biosensors, such as affinity-based biosensors, provide an alternative analytical approach with a higher selectivity. This article reviews the recent advances in the field of biosensor developed for phosphate estimation in clinical and environmental samples, concerning the techniques involved, and the sensitivity toward phosphate ions. The biosensors have been classified and discussed on the basis of the number of enzymes used to develop the analytical system, and a comparative analysis has been performed.

  2. Interaction between Nitrogen and Phosphate Stress Responses in Sinorhizobium meliloti

    PubMed Central

    Hagberg, Kelly L.; Yurgel, Svetlana N.; Mulder, Monika; Kahn, Michael L.

    2016-01-01

    Bacteria have developed various stress response pathways to improve their assimilation and allocation of limited nutrients, such as nitrogen and phosphate. While both the nitrogen stress response (NSR) and phosphate stress response (PSR) have been studied individually, there are few experiments reported that characterize effects of multiple stresses on one or more pathways in Sinorhizobium meliloti, a facultatively symbiotic, nitrogen-fixing bacteria. The PII proteins, GlnB and GlnK, regulate the NSR activity, but analysis of global transcription changes in a PII deficient mutant suggest that the S. meliloti PII proteins may also regulate the PSR. PII double deletion mutants grow very slowly and pseudoreversion of the slow growth phenotype is common. To understand this phenomenon better, transposon mutants were isolated that had a faster growing phenotype. One mutation was in phoB, the response regulator for a two component regulatory system that is important in the PSR. phoB::Tn5 mutants had different phenotypes in the wild type compared to a PII deficient background. This led to the hypothesis that phosphate stress affects the NSR and conversely, that nitrogen stress affects the PSR. Our results show that phosphate availability affects glutamine synthetase activity and expression, which are often used as indicators of NSR activity, but that nitrogen availability did not affect alkaline phosphatase activity and expression, which are indicators of PSR activity. We conclude that the NSR is co-regulated by nitrogen and phosphate, whereas the PSR does not appear to be co-regulated by nitrogen in addition to its known phosphate regulation. PMID:27965651

  3. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Phosphated flour. 137.175 Section 137.175 Food and... CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and...

  4. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Phosphated flour. 137.175 Section 137.175 Food and... CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and...

  5. 21 CFR 137.175 - Phosphated flour.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Phosphated flour. 137.175 Section 137.175 Food and... CONSUMPTION CEREAL FLOURS AND RELATED PRODUCTS Requirements for Specific Standardized Cereal Flours and Related Products § 137.175 Phosphated flour. Phosphated flour, phosphated white flour, and...

  6. Tamoxifen citrate loaded ethosomes for transdermal drug delivery system: preparation and characterization.

    PubMed

    Sarwa, Khomendra Kumar; Suresh, Preeti K; Debnath, Manabendra; Ahmad, Mohammad Zaki

    2013-08-01

    Long term tamoxifen citrate therapy is imperative to treat several dermatological and hormonal sensitive disorders. Successful oral and parenteral administration of tamoxifen citrate has been challenging since it undergoes enzymatic degradation and has poor aqueous solubility issues. In the present work, tamoxifen citrate loaded ethosomes were prepared and characterized for transdermal applications. The prepared formulations were characterized for morphological features, particle size distribution, calorimetric attributes, zeta potential and drug entrapment. Permeation profile of prepared ethosomes was compared with liposomes and hydroethonalic solution across cellophane membrane and human cadaver skin. Results of the permeation studies indicate that ethosomes were able to deliver >90% drug within 24 hours of application, while liposomes and hydroethanolic solution delivered only 39.04% and 36.55% respectively. Skin deposition and stability studies are also reported.

  7. [Fenibut and its citrate prevent psychoneurological disorders caused by chronic stress (paradoxical sleep deprivation)].

    PubMed

    Tiurenkov, I N; Bagmetova, V V; Borodkina, L E; Berestovitskaia, V M; Vasil'eva, O S

    2012-01-01

    The antistress protective action of two structural analogs of GABA, fenibut and its salt with citric acid (fenibut citrate, citrocard, RGPU-147), has been studied using a model of chronic stress caused by seven-fold 24-h deprivation of paradoxical sleep phase at an interval of 24 h between the deprivations. It is established that fenibut and fenibut citrate produce a protective action by (i) reducing the intensity of emotional disorders in the open-field test and elevated plus maze test, (ii) decreasing cognitive disorders in the tests for conditioned avoidance response and extrapolatory deliverance; and (iii) limiting stress reaction due to a decrease in the intensity of adrenal hypertrophy, thymus involution, and stomach mucous membrane ulceration. Fenibut citrate surpasses fenibut in the intensity of antistress protective action.

  8. Sildenafil citrate for the management of fetal growth restriction and oligohydramnios.

    PubMed

    Choudhary, Rana; Desai, Kavita; Parekh, Hetal; Ganla, Kedar

    2016-01-01

    Fetal growth restriction (FGR) and preeclampsia are the major causes of neonatal morbidity and mortality, which affect up to 8% of all pregnancies. The pathogenesis in FGR is an abnormal trophoblastic invasion leading to compromised uteroplacental circulation. However, in spite of this understanding and identification of high-risk patients, the management options are limited. There are some new studies which have demonstrated the role of sildenafil citrate in improving vasodilatation of small myometrial vessels and therefore improvement in amniotic fluid index, fetal weight, and even uterine and umbilical artery Doppler patterns. We report here the case of a 31-year-old female with infertility and preconceptional thin endometrium responding well to sildenafil citrate, followed by conception. However, she presented with an early-onset FGR at 26 weeks of gestation, and again after treatment with sildenafil citrate, showed improvement in amniotic fluid index and fetal weight, finally resulting in delivery of a full-term healthy baby with uneventful neonatal course.

  9. Interaction of monolaurin, eugenol and sodium citrate on growth of common meat spoilage and pathogenic organisms.

    PubMed

    Blaszyk, M; Holley, R A

    1998-02-17

    Interactions of monolaurin, eugenol (phenolic compound) and sodium citrate (chelator) on the growth of six organisms including common meat spoilage (Lactobacillus curvatus, Lactobacillus sake, Leuconostoc mesenteroides, Brochothrix thermosphacta) and pathogenic (Escherichia coli O157:H7 and Listeria monocytogenes) organisms were investigated. The combinations of 100 to 250 ppm monolaurin with 500 and 1000 ppm eugenol, and 0.2 and 0.4% sodium citrate were more effective than each component separately. More than one combination prevented detectable growth of each organism. Lactic acid bacteria (LAB) and E. coli O157:H7 were most resistant and L. monocytogenes and B. thermosphacta most sensitive to control by the chosen combinations. The presence of sodium citrate was necessary to yield potent inhibition of Lb. curvatus and Lb. sake growth by the monolaurin and eugenol combinations.

  10. Comparison of fluorine-18-2-fluorodeoxyglucose and gallium-67 citrate imaging for detection of lymphoma

    SciTech Connect

    Paul, R.

    1987-03-01

    Patients with lymphomas are conventionally imaged with (/sup 67/Ga)citrate for tumor detection and determination of dissemination. Fluorine-18-2-fluoro-2-deoxy-D-glucose (( /sup 18/F)FDG) is a radiopharmaceutical that accumulates into tissues where glucose utilization is enhanced, such as tumors. Six cancer patients (five non-Hodgkin's lymphomas, one endodermal retroperitoneal sinus carcinoma) were imaged with (/sup 18/F)FDG and (/sup 67/Ga)citrate whole-body scintigraphies in order to compare the sensitivities of these two tumor imaging radiopharmaceuticals. Among the five untreated lymphoma patients, two /sup 67/Ga scans and four (/sup 18/F)FDG scans were positive; in the patient with the retroperitoneal carcinoma who had a positive (/sup 18/F)FDG scan before treatment, both scans were negative after treatment. Fluorine-18 FDG may be a more sensitive tumor-detecting radiopharmaceutical for non-Hodgkin's lymphoma than (/sup 67/Ga)citrate.

  11. Effects of Sodium Citrate Concentration on Electroless Ni-Fe Bath Stability and Deposition

    NASA Astrophysics Data System (ADS)

    Jung, Myung-Won; Kang, Sung K.; Lee, Jae-Ho

    2014-01-01

    In this research, electroless Ni-Fe bath stability and deposition characteristics were investigated for various sodium citrate concentrations. Complexing agents such as sodium citrate are one of the main components of such electroless plating baths. Since they could play various roles such as maintaining pH stability, preventing precipitation of metal salts, and reducing the concentrations of free metal ions, the concentration of complexing agents in the plating bath is an important parameter for electroless deposition processes. In this research, unstable baths were obtained for insufficient sodium citrate concentrations, and these phenomena were analyzed with ChemEQL. Moreover, the deposition characteristics of electroless Ni-Fe for under bump metallurgy diffusion barriers were also investigated using energy-dispersive spectroscopy and field-emission scanning electron microscopy.

  12. SECONDARY HYPERPARATHYROIDISM AFTER BARIATRIC SURGERY: TREATMENT IS WITH CALCIUM CARBONATE OR CALCIUM CITRATE?

    PubMed Central

    BARETTA, Giorgio Alfredo Pedroso; CAMBI, Maria Paula Carlini; RODRIGUES, Arieli Luz; MENDES, Silvana Aparecida

    2015-01-01

    Background : Bariatric surgery, especially Roux-en-Y gastric bypass, can cause serious nutritional complications arising from poor absorption of essential nutrients. Secondary hyperparathyroidism is one such complications that leads to increased parathyroid hormone levels due to a decrease in calcium and vitamin D, which may compromise bone health. Aim : To compare calcium carbonate and calcium citrate in the treatment of secondary hyperparathyroidism. Method : Patients were selected on the basis of their abnormal biochemical test and treatment was randomly done with citrate or calcium carbonate. Results : After 60 days of supplementation, biochemical tests were repeated, showing improvement in both groups. Conclusion : Supplementation with calcium (citrate or carbonate) and vitamin D is recommended after surgery for prevention of secondary hyperparathyroidism. PMID:26537273

  13. Phloretin and citrate promote the differentiation rate from epimastigote to metacyclic forms of Trypanosoma cruzi.

    PubMed

    Adroher, F J; Osuna, A; Lupiáñez, J A

    1991-11-01

    We have investigated the effects of the metabolic inhibitors, phloretin, 2-deoxy-D-glucose, maleate and trans-aconitate, as well as two intermediates of the tricarboxylic-acid cycle, acetate and citrate, on the growth and metacyclogenesis of Trypanosoma cruzi. 0.1 mM phloretin increased the percentage of metacyclic forms about 2.7-fold without affecting growth rate, whereas the other inhibitors had no apparent effect on either growth or differentiation rates. The addition of 5 mM citrate stimulated differentiation by about 2.6-fold. When either 10 mM citrate or 10 mM acetate were added, on the other hand, both the growth and differentiation rates were severely inhibited.

  14. Acute versus chronic supplementation of sodium citrate on 200 m performance in adolescent swimmers

    PubMed Central

    2014-01-01

    Background A double-blinded, placebo-controlled, cross-over design was used to investigate whether two different sodium citrate dihydrate (Na-CIT) supplementation protocols improve 200 m swimming performance in adolescent swimmers. Methods Ten, male swimmers (14.9 ± 0.4 years of age; 63.5 ± 4 kg) performed four 200 m time trials with the following treatments: acute (ACU) supplementation (0.5 g kg-1 administered 120 min pre-trial), acute placebo (PLC-A), chronic (CHR) supplementation (0.1 g∙kg-1 for three days and 0.3 g kg-1 on the forth day 120 min pre-trial), and chronic placebo (PLC-C). The order of the trials was randomized, with at least a six-day wash-out period between trials. Blood samples were collected by finger prick pre-ingestion, 100 min post-ingestion, and 3 min post-trial. Performance time, rate of perceived exertion, pH, base excess, bicarbonate and lactate concentration were measured. Results Post-ingestion bicarbonate and base excess were higher (P < 0.05) in both the ACU and CHR trials compared to placebo showing adequate pre-exercise alkalosis. However, performance time, rate of perceived exertion as well as post-trial pH and lactate concentration were not significantly different between trials. Further analysis revealed that five swimmers, identified as responders, improved their performance time by 1.03% (P < 0.05) and attained higher post-trial lactate concentrations in the ACU versus PLC-A trial (P < 0.05). They also had significantly higher post-trial lactate concentrations compared to the non-responders in the ACU and CHR trials. Conclusions Acute supplementation of Na-CIT prior to 200 m swimming performance led to a modest time improvement and higher blood lactate concentrations in only half of the swimmers while the chronic Na-CIT supplementation did not provide any ergogenic effect in this group of adolescent swimmers. Trial registration Clinicaltrials.gov NCT01835912. PMID:24944546

  15. Selective cytopheretic inhibitory device with regional citrate anticoagulation and portable sorbent dialysis.

    PubMed

    Pino, Christopher J; Farokhrani, Amin; Lou, Liandi; Smith, Peter L; Johnston, Kimberly; Buffington, Deborah A; Humes, H David

    2013-02-01

    Selective cytopheretic inhibitory device (SCD) therapy is an immunomodulatory treatment provided by a synthetic biomimetic membrane in an extracorporeal circuit, which has shown promise in preclinical large animal models of severe sepsis as well as in clinical trials treating patients with acute kidney injury and multiple organ failure. During SCD therapy, citrate is administered to lower ionized calcium levels in blood for anticoagulation and inhibition of leukocyte activation. Historically, citrate has been known to interfere with sorbent dialysis, therefore, posing a potential issue for the use of SCD therapy with a portable dialysis system. This sorbent dialysis SCD (sorbent SCD) would be well suited for battlefield and natural disaster applications where the water supply for standard dialysis is limited, and the types of injuries in those settings would benefit from SCD therapy. In order to explore the compatibility of sorbent and SCD technologies, a uremic porcine model was tested with the Allient sorbent dialysis system (Renal Solutions Incorporated, Fresenius Medical Care, Warrendale, PA, USA) and concurrent SCD therapy with regional citrate anticoagulation. The hypothesis to be assessed was whether the citrate load required by the SCD could be metabolized prior to recirculation from systemic blood back into the therapeutic circuit. Despite the fact that the sorbent SCD maintained urea clearance without any adverse hematologic events, citrate load for SCD therapy caused an interaction with the sorbent column resulting in elevated, potentially toxic aluminum levels in dialysate and in systemic blood. Alternative strategies to implement sorbent-SCD therapy will be required, including development of alternate urease-sorbent column binding chemistry or further changes to the sorbent-SCD therapeutic circuit along with determining the minimum citrate concentration required for efficacious SCD treatment.

  16. Dietary and Lifestyle Factors and Medical Conditions Associated with Urinary Citrate Excretion

    PubMed Central

    Taylor, Eric N.; Curhan, Gary C.

    2013-01-01

    Summary Background and objectives Lower urinary citrate excretion is a risk factor for nephrolithiasis and associated with metabolic acidosis and higher prevalence of hypertension and insulin resistance. This study sought to quantify the independent predictors of urinary citrate excretion in population-based cohorts. Design, setting, participants, & measurements A cross-sectional study of 2561 individuals from the Health Professionals Follow-Up Study and Nurses’ Health Studies I and II who provided two 24-hour urine collections was conducted. Dietary data were ascertained from the semiquantitative food frequency questionnaire. Lifestyle and disease data were derived from responses to biennial questionnaires. Multivariable linear regression was used to quantify the predictors of urinary citrate excretion. Results After adjusting for age, urinary creatinine, dietary, and other factors, higher intake of nondairy animal protein (per 10 g/d; −20 mg/d; 95% confidence interval [−29 to −11]), higher body mass index (per 1 kg/m2; −4 mg/d; [−6 to −2]), and history of nephrolithiasis (−57 mg/d; [−79 to −36]), hypertension (−95 mg/d; [−119 to −71]), gout (−104 mg/d; [−155 to −54]), and thiazide use (−34 mg/d; [−68 to −1]) were independently associated with lower 24-hour urinary citrate excretion. Higher intake of potassium (per 1000 mg/d; 53 mg/d; [33 to 74]), higher urinary sodium (per 100 mEq/d; 56 mg/d; [31 to 80]), and history of diabetes (61 mg/d; [21 to 100]) were independently associated with higher citrate excretion. Conclusions Several dietary and lifestyle factors and medical conditions are independently associated with urinary citrate excretion. PMID:23449767

  17. Is magnesium citrate treatment effective on pain, clinical parameters and functional status in patients with fibromyalgia?

    PubMed

    Bagis, Selda; Karabiber, Mehmet; As, Ismet; Tamer, Lülüfer; Erdogan, Canan; Atalay, Ayçe

    2013-01-01

    The aims of this study were to investigate the relationship between magnesium levels and fibromyalgia symptoms and to determine the effect of magnesium citrate treatment on these symptoms. Sixty premenopausal women diagnosed with fibromyalgia according to the ACR criteria and 20 healthy women whose age and weight matched the premenopausal women were evaluated. Pain intensity, pain threshold, the number of tender points, the tender point index, the fibromyalgia impact questionnaire (FIQ), the Beck depression and Beck anxiety scores and patient symptoms were evaluated in all the women. Serum and erythrocyte magnesium levels were also measured. The patients were divided into three groups. The magnesium citrate (300 mg/day) was given to the first group (n = 20), amitriptyline (10 mg/day) was given to the second group (n = 20), and magnesium citrate (300 mg/day) + amitriptyline (10 mg/day) treatment was given to the third group (n = 20). All parameters were reevaluated after the 8 weeks of treatment. The serum and erythrocyte magnesium levels were significantly lower in patients with fibromyalgia than in the controls. Also there was a negative correlation between the magnesium levels and fibromyalgia symptoms. The number of tender points, tender point index, FIQ and Beck depression scores decreased significantly with the magnesium citrate treatment. The combined amitriptyline + magnesium citrate treatment proved effective on all parameters except numbness. Low magnesium levels in the erythrocyte might be an etiologic factor on fibromyalgia symptoms. The magnesium citrate treatment was only effective tender points and the intensity of fibromyalgia. However, it was effective on all parameters when used in combination with amitriptyline.

  18. Sildenafil citrate monohydrate-cyclodextrin nanosuspension complexes for use in metered-dose inhalers.

    PubMed

    Sawatdee, Somchai; Phetmung, Hirihattaya; Srichana, Teerapol

    2013-10-15

    Sildenafil is a selective phosphodiesterase-5 inhibitor used for the treatment of erectile dysfunction and pulmonary hypertension. Sildenafil citrate monohydrate was complexed with α-, hydroxypropyl-β- and γ-cyclodextrin (α-CD, HP-β-CD and γ-CD, respectively) to enhance its water solubility. The complexes of sildenafil citrate monohydrate with all types of CDs were characterized by phase solubility diagrams, (1)H and (13)C NMR, and dielectric constants. Sildenafil citrate monohydrate complexed with CDs was developed as nanosuspensions for use in a pressurized metered-dose inhaler (pMDI). Sildenafil citrate monohydrate pMDI formulations were prepared by a bottom-up process using dried ethanol as a solvent and HFA-134a as an antisolvent and propellant in order to form nanosuspensions. A 3×3 factorial design was applied for the contents of the dried ethanol and HFA-134a propellant. The phase solubility profiles of the sildenafil and cyclodextrins were described as AL type with a mole ratio 1:1. The piperazine moiety of sildenafil formed an inclusion in the cavity of the CDs. The particle diameters of the sildenafil citrate monohydrate suspensions in pMDIs were all within a nanosuspension size range. An assay of the sildenafil content showed that the formation of complexes with CDs was close to 100%. In the case of the formulations with CDs, the emitted doses varied within 97.4±10.8%, the fine particle fractions (FPFs) were in a range of 45-81%, the fine particle dose (FPD) was 12.6±2.0 μg and the mass median aerodynamic diameters (MMADs) were 1.86±0.41 μm. In contrast, the formulations without CDs produced a low emitted dose of sildenafil (<60%). Therefore, only sildenafil citrate monohydrate pMDI formulations containing CDs were suitable for use as aerosols.

  19. Use of Potassium Citrate to Reduce the Risk of Renal Stone Formation During Spaceflight

    NASA Technical Reports Server (NTRS)

    Whitson, P. A.; Pietrzyk, R. A.; Sams, C. F.; Jones, J. A.; Nelman-Gonzalez, M.; Hudson, E. K.

    2008-01-01

    Introduction: NASA s Vision for Space Exploration centers on exploration class missions including the goals of returning to the moon and landing on Mars. One of NASA s objectives is to focus research on astronaut health and the development of countermeasures that will protect crewmembers during long duration voyages. Exposure to microgravity affects human physiology and results in changes in the urinary chemical composition favoring urinary supersaturation and an increased risk of stone formation. Nephrolithiasis is a multifactorial disease and development of a renal stone is significantly influenced by both dietary and environmental factors. Previous results from long duration Mir and short duration Shuttle missions have shown decreased urine volume, pH, and citrate levels and increased calcium. Citrate, an important inhibitor of calcium-containing stones, binds with urinary calcium reducing the amount of calcium available to form stones. Citrate inhibits renal stone recurrence by preventing crystal growth, aggregation, and nucleation and is one of the most common therapeutic agents used to prevent stone formation. Methods: Thirty long duration crewmembers (29 male, 1 female) participated in this study. 24-hour urines were collected and dietary monitoring was performed pre, in, and postflight. Crewmembers in the treatment group received two potassium citrate (KCIT) pills, 10 mEq/pill, ingested daily beginning 3 days before launch, all inflight days and through 14 days postflight. Urinary biochemical and dietary analyses were completed. Results: KCIT treated subjects exhibited decreased urinary calcium excretion and maintained the levels of calcium oxalate supersaturation risk at their preflight levels. The increased urinary pH levels in these subjects reduced the risk of uric acid stones. Discussion: The current study investigated the use of potassium citrate as a countermeasure to minimize the risk of stone formation during ISS missions. Results suggest that

  20. Comparison of Elaeagnus angustifolia Extract and Sildenafil Citrate on Female Orgasmic Disorders: A Randomized Clinical Trial

    PubMed Central

    Akbarzadeh, Marzieh; Zeinalzadeh, Sanaz; Zolghadri, Jaleh; Mohagheghzadeh, Abdolali; Faridi, Pouya; Sayadi, Mehrab

    2014-01-01

    Background Orgasmic disorder can create a feeling of deprivation and failure and provide mental problems, incompatibility and marital discord. This study aimed to compare the effects of Elaeagnus angustifolia flower extract and sildenafil citrate on female orgasmic disorder in women in 2013. Methods In this randomized clinical trial, 125 women between 18-40 years old who suffered from orgasmic disorder were divided into three E. angustifolia, sildenafil citrate and control groups. The data were gathered using Female Sexual Function Index and through measurement of TSH and prolactin. The first intervention group had to consume 4.5 gr E. angustifolia extract in two divided doses for 35 days and the second one had to use 50 mg sildenafil citrate tablets for 4 weeks one hour before their sexual relationship. However, the control group had to consume the placebo. The data were analyzed using paired t-test, one-way ANOVA, and Bonferroni posthoc test and p<0.05 was considered significant. Results The frequency of orgasmic disorder before the intervention was 41.5%, 40.5%, and 57.1% in E. angustifolia, sildenafil citrate, and control groups, respectively (p=0.23). However, these measures were respectively 29.3%, 16.7%, and 50% after the intervention (p=0.004). A significant difference between the two groups regarding sexual satisfaction after the intervention (p=0.003) compared to the beginning of the study (p=0.356). Besides, the highest reduction of changes after the intervention (58.82%) was observed in the sildenafil citrate group. Conclusion Both E. angustifolia extract and sildenafil citrate were effective in reduction of the frequency of orgasmic disorder in women. PMID:25473627

  1. Light wavelength influence on surface plasmon resonance in citrate-gold nanosystems

    NASA Astrophysics Data System (ADS)

    Lupusoru, Raoul-Vasile; Pricop, Daniela A.; Andries, Maria; Creanga, Dorina

    2016-12-01

    Citrate-gold particles were yielded according to classical method of auric salt reduction in two different synthesis media aiming to use them further applications in biomedical and environmental domains. The analysis of citrate-gold interaction was done through UV-vis and IR spectroscopy as well as by Transmission Electron Microscopy (TEM) and Dark Field (DF) Microscopy. Average particle size was higher for citrate-gold NPs synthesized with NaOH (32.5 nm) than for NPs synthesized with NaCl (15 nm). Dimensional histograms of one year aged colloidal suspensions presented mean size of 29 nm and respectively 18 nm. The influence of 90 min light exposure, analyzed by UV-vis, evidenced that for both NaOH synthesis protocol and NaCl protocol, plasmon band maxima at 528 nm and respectively 538 nm didn't changed, neither for white nor for green light. For one year aged samples this band shifted to 540 nm for green light irradiation in the case of citrate-gold NPs synthesized with NaOH. Also, for these NPs, both green and white light exposures resulted in plasmon band intensity changes for native as well as for aged samples. FTIR investigation showed also different changes at the level of the intensity of main vibration bands of citrate-gold after exposure to light, suggesting stronger adsorption of citrate in the case of NaCl addition in the initial reaction medium than in the case of NaOH. Finally, the utilization of NaCl in the synthesis protocol seems to favor the synthesis of more stable and lower toxicity colloidal suspensions, both during time and under the light irradiation.

  2. Modulation of calcium oxalate monohydrate crystallization by citrate through selective binding to atomic steps

    SciTech Connect

    Qiu, S R; Wierzbicki, A; Salter, E A; Zepeda, S; Orme, C A; Hoyer, J R; Nancollas, G H; Cody, A M; De Yoreo, J J

    2004-10-19

    The majority of human kidney stones are composed primarily of calcium oxalate monohydrate (COM) crystals. Thus, determining the molecular mechanisms by which urinary constituents modulate calcium oxalate crystallization is crucial for understanding and controlling urolithiassis in humans. A comprehensive molecular-scale view of COM shape modification by citrate, a common urinary constituent, obtained through a combination of in situ atomic force microscopy (AFM) and molecular modeling is now presented. We show that citrate strongly influences the growth morphology and kinetics on the (-101) face but has much lower effect on the (010) face. Moreover, binding energy calculations show that the strength of the citrate-COM interaction is much greater at steps than on terraces and is highly step-specific. The maximum binding energy, -166.5 kJ {center_dot} mol{sup -1}, occurs for the [101] step on the (-101) face. In contrast, the value is only -56.9 kJ {center_dot} mol-1 for the [012] step on the (010) face. The binding energies on the (-101) and (010) terraces are also much smaller, -65.4 and -48.9 kJ {center_dot} mol{sup -1} respectively. All other binding energies lie between these extremes. This high selectivity leads to preferential binding of citrate to the acute [101] atomic steps on the (-101) face. The strong citrate-step interactions on this face leads to pinning of all steps, but the anisotropy in interaction strength results in anisotropic reductions in step kinetics. These anisotropic changes in step kinetics are, in turn, responsible for changes in the shape of macroscopic COM crystals. Thus, the molecular scale growth morphology and the bulk crystal habit in the presence of citrate are similar, and the predictions of molecular simulations are fully consistent with the experimental observations.

  3. Isoexergonic Conformations of Surface-Bound Citrate Regulated Bioinspired Apatite Nanocrystal Growth.

    PubMed

    Wang, Ziqiu; Xu, Zhijun; Zhao, Weilong; Chen, Wei; Miyoshi, Toshikazu; Sahai, Nita

    2016-10-05

    The superior biomechanical properties of bone and dentin are dictated, in part, by the unique plate-like morphology of hydroxyapatite (HAP) nanocrysals within a hierarchically assembled collagen matrix. Understanding the mechanism of crystal growth and thus morphology is important to the rational design of bioinspired apatite nanocrystals for orthopedic and dental applications. Citrate has long been proposed to modulate apatite crystal growth, but major questions exist regarding the HAP-bound citrate conformations and the identities of the interacting functional groups and HAP surface sites. Here, we conducted a comprehensive investigation of the mechanism from the angstrom to submicrometer scale by detailed correlation of the results of high-level metadynamics simulations, employing force-fields benchmarked to experiment and density functional theory calculations with the results of high resolution transmission electron microscopy, nuclear magnetic resonance spectroscopy, solution analysis, and thermogravimetric analysis. Crystal morphology changed from needle- to plate-like with increasing citrate concentration. Citrate adsorbed more strongly on the HAP (100) face than on the (001) face, thus resulting in preferential growth in the [001] direction and the plate-like morphology. Two very different bound conformations were obtained, involving interactions of either one or both terminal carboxyl groups with three or five surface calcium ions, respectively, and a hydrogen bond between the citrate hydroxyl and the HAP surface. Remarkably, despite fewer interaction sites in the single bound carboxyl conformation, the structures were isoexergonic, so both exist at equilibrium. Identification of the former conformation is significant because it allows a greater adsorption density than is traditionally assumed and can help explain concentration-dependence of citrate in modulating crystal morphology. These unique results were enabled first by the application of advanced

  4. Pharmacokinetics of Ferric Pyrophosphate Citrate, a Novel Iron Salt, Administered Intravenously to Healthy Volunteers

    PubMed Central

    Swinkels, Dorine W.; Ikizler, T. Alp; Gupta, Ajay

    2016-01-01

    Abstract Ferric pyrophosphate citrate (Triferic) is a water‐soluble iron salt that is administered via dialysate to maintain iron balance and hemoglobin in hemodialysis patients. This double‐blind, randomized, placebo‐controlled, single‐, ascending‐dose study was conducted to evaluate the pharmacokinetics and safety of intravenous ferric pyrophosphate citrate in 48 healthy iron‐replete subjects (drug, n = 36; placebo, n = 12). Single doses of 2.5, 5.0, 7.5, or 10 mg of ferric pyrophosphate citrate or placebo were administered over 4 hours, and single doses of 15 or 20 mg of ferric pyrophosphate citrate or placebo were administered over 12 hours via intravenous infusion. Serum total iron (sFetot), transferrin‐bound iron (TBI), hepcidin‐25, and biomarkers of oxidative stress and inflammation were determined using validated assays. Marked diurnal variation in sFetot was observed in placebo‐treated subjects. Concentrations of sFetot and TBI increased rapidly after drug administration, with maximum serum concentrations (Cmax) reached at the end of infusion. Increases in baseline‐corrected Cmax and area under the concentration‐time curve from 0 to the time of the last quantifiable concentration (AUC0‐t) were dose proportional up to 100% transferrin saturation. Iron was rapidly cleared (apparent terminal phase half‐life 1.2‐2 hours). No significant changes from baseline in serum hepcidin‐25 concentration were observed at end of infusion for any dose. Biomarkers of oxidative stress and inflammation were unaffected. Intravenous doses of ferric pyrophosphate citrate were well tolerated. These results demonstrate that intravenous ferric pyrophosphate citrate is rapidly bound to transferrin and cleared from the circulation without increasing serum hepcidin levels or biomarkers of oxidative stress or inflammation. PMID:27557937

  5. Aggregation Kinetics of Citrate and Polyvinylpyrrolidone Coated Silver Nanoparticles in Monovalent and Divalent Electrolyte Solutions

    PubMed Central

    Huynh, Khanh An; Chen, Kai Loon

    2011-01-01

    The aggregation kinetics of silver nanoparticles (AgNPs) that were coated with two commonly used capping agents—citrate and polyvinylpyrrolidone (PVP)—were investigated. Time-resolved dynamic light scattering (DLS) was employed to measure the aggregation kinetics of the AgNPs over a range of monovalent and divalent electrolyte concentrations. The aggregation behavior of citrate-coated AgNPs in NaCl was in excellent agreement with the predictions based on Derjaguin–Landau–Verwey–Overbeek (DLVO) theory, and the Hamaker constant of citrate-coated AgNPs in aqueous solutions was derived to be 3.7 × 10-20 J. Divalent electrolytes were more efficient in destabilizing the citrate-coated AgNPs, as indicated by the considerably lower critical coagulation concentrations (2.1 mM CaCl2 and 2.7 mM MgCl2 vs. 47.6 mM NaCl). The PVP-coated AgNPs were significantly more stable than citrate-coated AgNPs in both NaCl and CaCl2, which is likely due to steric repulsion imparted by the large, non-charged polymers. The addition of humic acid resulted in the adsorption of the macromolecules on both citrate- and PVP-coated AgNPs. The adsorption of humic acid induced additional electrosteric repulsion that elevated the stability of both nanoparticles in suspensions containing NaCl or low concentrations of CaCl2. Conversely, enhanced aggregation occurred for both nanoparticles at high CaCl2 concentrations due to interparticle bridging by humic acid clusters. PMID:21630686

  6. Ferric pyrophosphate citrate administered via dialysate reduces erythropoiesis-stimulating agent use and maintains hemoglobin in hemodialysis patients.

    PubMed

    Gupta, Ajay; Lin, Vivian; Guss, Carrie; Pratt, Raymond; Ikizler, T Alp; Besarab, Anatole

    2015-11-01

    Ferric pyrophosphate citrate (FPC) is a water-soluble iron salt administered via dialysate to supply iron directly to transferrin. The PRIME study tested whether treatment with FPC could reduce prescribed erythropoiesis-stimulating agent (ESA) use and maintain hemoglobin in hemodialysis patients. This 9-month, randomized, placebo-controlled, double-blind, multicenter clinical study included 103 patients undergoing hemodialysis 3-4 times weekly. The FPC group received dialysate containing 2 μmol/l of iron. The placebo group received standard dialysate. A blinded central anemia management group facilitated ESA dose adjustments. Intravenous iron was administered according to the approved indication when ferritin levels fell below 200 μg/l. The primary end point was the percentage change from baseline in prescribed ESA dose at end of treatment. Secondary end points included intravenous iron use and safety. At the end of treatment, there was a significant 35% reduction in prescribed ESA dose in FPC-treated patients compared with placebo. The FPC patients used 51% less intravenous iron than placebo. Adverse and serious adverse events were similar in both groups. Thus, FPC delivered via dialysate significantly reduces the prescribed ESA dose and the amount of intravenous iron needed to maintain hemoglobin in chronic hemodialysis patients.

  7. Efficacy and safety of sildenafil citrate (Viagra) for the treatment of erectile dysfunction in men in Egypt and South Africa.

    PubMed

    Levinson, I P; Khalaf, I M; Shaeer, K Z M; Smart, D O

    2003-04-01

    The efficacy of sildenafil citrate (Viagra), an oral agent for the treatment of erectile dysfunction (ED), has been demonstrated in global studies. This 12-week randomized, double-blind, placebo-controlled, parallel-group, flexible-dose study assessed the efficacy and safety of sildenafil to treat ED in men in Egypt and South Africa. Men with ED of varied etiology were randomized to receive sildenafil 50 mg (n=128) or placebo (n=126); doses could be adjusted to 100 or 25 mg. Questions from the International Index of Erectile Function (IIEF) assessing the ability to achieve (Q3) and maintain (Q4) erections demonstrated a significant improvement with sildenafil compared with placebo (P<0.0001). Improved erections were reported by 74% of patients receiving sildenafil and 27% of those receiving placebo (P<0.0001). Headache, dyspepsia, and flushing were the most common adverse events in sildenafil-treated patients. These results are consistent with clinical trials in other countries. We conclude that sildenafil is an efficacious and well-tolerated treatment for men with ED in Egypt and South Africa.

  8. The effect of hardness on the stability of citrate-stabilized gold nanoparticles and their uptake by Daphnia magna.

    PubMed

    Lee, Byung-Tae; Ranville, James F

    2012-04-30

    The stability and uptake by Daphnia magna of citrate-stabilized gold nanoparticles (AuNPs) in three different hardness-adjusted synthetic waters were investigated. Negatively charged AuNPs were found to aggregate and settle in synthetic waters within 24 h. Sedimentation rates depended on initial particle concentrations of 0.02, 0.04, and 0.08 nM AuNPs. Hardness of the synthetic waters affected the aggregation of AuNPs and is explained by the compression of diffuse double layer of AuNPs due to the increasing ionic strength. The fractal dimension of AuNPs in the reaction-limited regime of synthetic waters averaged 2.228±0.126 implying the rigid structures of aggregates driven by the collision of small particles with the growing aggregates. Four-day old D. magna accumulated more than 90% of AuNPs in 0.04 nM AuNP suspensions without any observed mortality. Exposure to pre-aggregated AuNP for 48 h in hard water did not show any significant difference in uptake, suggesting D. magna can also ingest settled AuNP aggregates. D. magna exposed to AuNPs shed their exoskeleton whereas the control did not generate any molts over 48 h. This implies that D. magna removed AuNPs on their exoskeleton by producing molts to decrease any adverse effects of adhered AuNPs.

  9. A comparison of oral transmucosal fentanyl citrate and oral hydromorphone for inpatient pediatric burn wound care analgesia.

    PubMed

    Sharar, S R; Bratton, S L; Carrougher, G J; Edwards, W T; Summer, G; Levy, F H; Cortiella, J

    1998-01-01

    The ideal oral wound care analgesic for children should be palatable, provide potent analgesia of rapid onset and short duration, and require minimal, yet appropriate, monitoring. With use of a double-blinded crossover design, we compared the efficacy and safety of oral transmucosal fentanyl citrate (OTFC) (approximately 10 micrograms/kg) with the efficacy and safety of oral hydromorphone (60 micrograms/kg) in 14 pediatric inpatients (ages 4 to 17 years) undergoing daily burn wound care in a ward setting. Pulse oximetry, vital signs, side effects, patient pain scores, and observer scores for cooperation, anxiety, and sedation were recorded. Pulse oximetry, vital signs, cooperation, sedation, incidence of nausea or vomiting, and the amount of time it took to resume normal activities were similar in both treatment groups. OTFC resulted in improved pain scores before wound care and improved anxiolysis during wound care, but at other points it was similar in effect to hydromorphone. We conclude that OTFC is a safe and effective analgesic, that it may provide minor improvements in analgesia and anxiolysis compared with hydromorphone, and that it offers a palatable alternative route of opioid administration without intravenous access for wound care procedures in children.

  10. Seeing Double

    NASA Astrophysics Data System (ADS)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  11. Fabrication of Poly-l-lactic Acid/Dicalcium Phosphate Dihydrate Composite Scaffolds with High Mechanical Strength-Implications for Bone Tissue Engineering.

    PubMed

    Tanataweethum, Nida; Liu, Wai Ching; Goebel, W Scott; Li, Ding; Chu, Tien Min

    2015-11-04

    Scaffolds were fabricated from poly-l-lactic acid (PLLA)/dicalcium phosphate dihydrate (DCPD) composite by indirect casting. Sodium citrate and PLLA were used to improve the mechanical properties of the DCPD scaffolds. The resulting PLLA/DCPD composite scaffold had increased diametral tensile strength and fracture energy when compared to DCPD only scaffolds (1.05 vs. 2.70 MPa and 2.53 vs. 12.67 N-mm, respectively). Sodium citrate alone accelerated the degradation rate by 1.5 times independent of PLLA. Cytocompatibility of all samples were evaluated using proliferation and differentiation parameters of dog-bone marrow stromal cells (dog-BMSCs). The results showed that viable dog-BMSCs attached well on both DCPD and PLLA/DCPD composite surfaces. In both DCPD and PLLA/DCPD conditioned medium, dog-BMSCs proliferated well and expressed alkaline phosphatase (ALP) activity indicating cell differentiation. These findings indicate that incorporating both sodium citrate and PLLA could effectively improve mechanical strength and biocompatibility without increasing the degradation time of calcium phosphate cement scaffolds for bone tissue engineering purposes.

  12. Fabrication of Poly-l-lactic Acid/Dicalcium Phosphate Dihydrate Composite Scaffolds with High Mechanical Strength—Implications for Bone Tissue Engineering

    PubMed Central

    Tanataweethum, Nida; Liu, Wai Ching; Scott Goebel, W.; Li, Ding; Chu, Tien Min

    2015-01-01

    Scaffolds were fabricated from poly-l-lactic acid (PLLA)/dicalcium phosphate dihydrate (DCPD) composite by indirect casting. Sodium citrate and PLLA were used to improve the mechanical properties of the DCPD scaffolds. The resulting PLLA/DCPD composite scaffold had increased diametral tensile strength and fracture energy when compared to DCPD only scaffolds (1.05 vs. 2.70 MPa and 2.53 vs. 12.67 N-mm, respectively). Sodium citrate alone accelerated the degradation rate by 1.5 times independent of PLLA. Cytocompatibility of all samples were evaluated using proliferation and differentiation parameters of dog-bone marrow stromal cells (dog-BMSCs). The results showed that viable dog-BMSCs attached well on both DCPD and PLLA/DCPD composite surfaces. In both DCPD and PLLA/DCPD conditioned medium, dog-BMSCs proliferated well and expressed alkaline phosphatase (ALP) activity indicating cell differentiation. These findings indicate that incorporating both sodium citrate and PLLA could effectively improve mechanical strength and biocompatibility without increasing the degradation time of calcium phosphate cement scaffolds for bone tissue engineering purposes. PMID:26556380

  13. Double Your Major, Double Your Return?

    ERIC Educational Resources Information Center

    Del Rossi, Alison F.; Hersch, Joni

    2008-01-01

    We use the 2003 National Survey of College Graduates to provide the first estimates of the effect on earnings of having a double major. Overall, double majoring increases earnings by 2.3% relative to having a single major among college graduates without graduate degrees. Most of the gains from having a double major come from choosing fields across…

  14. Citrate-stabilized Q-CdSe seed-mediated synthesis of silver nanoparticles: The role of citrate moieties anchored to the Q-CdSe surface

    NASA Astrophysics Data System (ADS)

    Ingole, Pravin P.; Bhat, Mohsin A.

    2016-03-01

    Here, we try to explore a new dimension/role for citrate molecules in the bound state, i.e. anchored to the surface of cadmium selenide quantum dots (Q-CdSe), in the synthesis of metal nanoparticles (MNPs). Being labile, the citrate molecule is considered a good candidate for the stabilization of semiconductor quantum dots (QDs) such as Q-CdSe that can be used for further functionalization/modification of the surface properties of the QDs. In its free/ionic form (i.e. not bound to the surface), it is well known for its role as a reducing as well as a capping agent in the synthesis of silver and gold MNPs. A simple strategy for the preparation of silver MNPs following the chemical reduction of silver ions that is mediated by citrate-stabilized Q-CdSe seeds without addition of an external reducing agent is presented. The citrate moieties anchored to the surface of Q-CdSe are found to play an important role in the chemical reduction of silver ions. The obtained product was analysed by spectroscopic, microscopic and structural characterization techniques such as surface plasmon resonance (SPR), transmission electron microscopy (TEM) and cyclic voltammetry. The characteristic redox behaviour observed in cyclic voltammograms (CVs) also supports the formation of Ag MNPs in the samples. Further, the impact of the reaction solution pH on the feasibility of silver ion reduction by Q-CdSe seeds resulting into the formation of Ag MNPs is also briefly discussed.

  15. 76 FR 34048 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Preliminary Results of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-10

    ..., which are intermediate products in the production of citric acid, sodium citrate, and potassium citrate... factors of production (``FOP''), valued in a surrogate market-economy (``ME'') country or countries... respondents' factors of production.\\8\\ On November 17, 2010, Yixing Union identified both Indonesia and...

  16. 76 FR 4288 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Notice of Extension of...

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    2011-01-25

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF COMMERCE International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... review of the antidumping duty order on citric acid and certain citrate salts (``citric acid'') from...

  17. 76 FR 77206 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Final Results of...

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    2011-12-12

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China...'') has completed its administrative review of the countervailing duty (``CVD'') order on citric acid and... Citric Acid and Certain Citrate Salts from the People's Republic of China: Preliminary Results...

  18. 76 FR 49735 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Partial Rescission of...

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    2011-08-11

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... review of the countervailing duty order on citric acid and certain citrate salts (``citric acid'') from..., 2011, Huangshi Xinghua Biochemical Co., Ltd. (``Xinghua''), a producer and exporter of citric...

  19. 77 FR 33167 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Preliminary Results of...

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    2012-06-05

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China... conducting an administrative review of the countervailing duty (CVD) order on citric acid and citrate salts.... SUPPLEMENTARY INFORMATION: Background On May 29, 2009, the Department published a CVD order on citric acid...

  20. 76 FR 47146 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

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    2011-08-04

    ... International Trade Administration Citric Acid and Certain Citrate Salts From the People's Republic of China...'') published the initiation of the administrative review of the antidumping duty order on citric acid and certain citrate salts (``citric acid'') from the People's Republic of China (``PRC''). See Initiation...