Contributions of citrate in redox potential maintenance and ATP production: metabolic pathways and their regulation in Lactobacillus panis PM1.

Science.gov (United States)

Kang, Tae Sun; Korber, Darren R; Tanaka, Takuji

2013-10-01

Lactobacillus panis PM1 belongs to the group III heterofermentative lactobacilli and can utilize various NADH-reoxidizing routes (e.g., citrate, glycerol, and oxygen) according to environmental conditions. In this study, we investigated the ability of L. panis PM1 to produce succinate, acetate, and lactate via citrate utilization. Possible pathways, as well as regulation, for citrate metabolism were examined on the basis of the genome sequence data and metabolic profiles of L. panis PM1. The presence of citrate led to the up-regulation, at the transcriptional level, of the genes encoding for citrate lyase, malate dehydrogenase, and malic enzyme of the citrate pathways by 10- to 120-fold. The transcriptional regulator of the dha operon coding for glycerol dehydratase of L. panis PM1 repressed the expression of the citrate lyase gene (10-fold). Metabolite analyses indicated that the transcriptional enhancement by citrate stimulated succinate yield. Citrate metabolism contributed to energy production by providing a major alternate pathway for NAD(+) regeneration and allowed acetyl phosphate to yield acetate/ATP instead of ethanol/NAD(+). Additionally, a branching pathway from oxaloacetate to pyruvate increased the pool of lactate, which was then used to produce ATP during stationary phase. However, the redirection of NADH-to-citrate utilization resulted in stress caused by end-products (i.e., succinate and acetate). This stress reduced succinate production by up to 50 % but did not cause significant changes at transcriptional level. Overall, citrate utilization was beneficial for the growth of L. panis PM1 by providing a NAD(+) regeneration route and producing extra ATP.

Flotation extraction of tributyl phosphate from s olutions

International Nuclear Information System (INIS)

Skrylev, L.D.; Tkachenko, N.V.; Sazonova, V.F.

1983-01-01

Results of investigations, conducted for revealing the possibility of flotation extraction of emulsificated and actually dissolved extractants, tributyl phosphate (TBP) in particular, are given. The possibility of flotation extraction of emulsificated and actually dissolved TBP by its non-reagent flotation was established experimeptally. It was also established that the kinetics of flotation TBP extraction is described by the equation, similar to the reaction equation of the first order. The process of non-reagent TBP flotation proceeds most successfully in pH=6.5-7.5 range

SHORT COMMUNICATION SYNTHESIS OF TRIBUTYL CITRATE ...

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hysteresis loop exhibits at high relative pressure corresponding to capillary condensation. From. BET method and BJH analysis, the mesoporous molecular sieve MCM-41 possesses a uniformly sized mesoporous with diameters 2.8 nm, larger surface area of more than 573 m2/g. Characterization of TBC. The structure of ...

Experimental study on thermal hazard of tributyl phosphate-nitric acid mixtures using micro calorimeter technique

Energy Technology Data Exchange (ETDEWEB)

Sun, Qi; Jiang, Lin; Gong, Liang; Sun, Jin-Hua, E-mail: sunjh@ustc.edu.cn

2016-08-15

Highlights: • Heat flows after mixing TBP with nitric acid are of different orders of magnitude. • Thermodynamics and kinetics of tributyl phosphate-nitric acid mixtures are derived. • Tributyl phosphate directly reacts with nitric acid and form organic red oil. • Thermal runaway could occur at 79 °C with a high nitric acid concentration. - Abstract: During PUREX spent nuclear fuel reprocessing, mixture of tributyl phosphate (TBP) and hydrocarbon solvent are employed as organic solvent to extract uranium in consideration of radiation contaminated safety and resource recycling, meanwhile nitric acid is utilized to dissolve the spent fuel into small pieces. However, once TBP contacts with nitric acid or nitrates above 130 °C, a heavy “red oil” layer would occur accompanied by thermal runaway reactions, even caused several nuclear safety accident. Considering nitric acid volatility and weak exothermic detection, C80 micro calorimeter technique was used in this study to investigate thermal decomposition of TBP mixed with nitric acid. Results show that the concentration of nitric acid greatly influences thermal hazard of the system by direct reactions. Even with a low heating rate, if the concentration of nitric acid increases due to evaporation of water or improper operations, thermal runaway in the closed system could start at a low temperature.

Extraction with tributyl phosphate (TBP) from ferric nitrate solutions

International Nuclear Information System (INIS)

Kolarik, Z.; Grudpan, K.

1985-01-01

Ferric nitrate acts as a strong salting-out agent in the extraction of thorium(IV), uranyl, europium(III), samarium(III) and zirconium(IV) nitrates as well as of nitric acid with tributyl phosphate in dodecane. Nitric acid, if present in the extraction system together with large amounts of ferric nitrate, markedly suppresses the extraction of thorium(IV) and lanthanides(III) but significantly supports the extraction of zirconium(IV). Separation factors of different metal pairs are presented as functions of the concentrations of ferric nitrate and nitric acid

Redox reactions of neptunium in tributyl phosphate-dodecane mixtures

International Nuclear Information System (INIS)

Wehrey, F.

1989-01-01

In relation with the reprocessing of irradiated fuels, disproportionation and oxidation by nitric acid of pentavalent neptunium in tributyl phosphate-dodecane mixtures have been studied. The experimental part of this work is based on spectrophotometric measurements. The disproportionation of pentavalent neptunium in organic perchloric medium is a second order reaction with respect to neptunium V. The reaction rate is strongly influenced by the perchloric acid concentration and has a higher value than in an aqueous medium. The reverse reaction in nitric media is a first order with respect to tetravalent and hexavalent ions. The reaction rate is a function of the reverse of the square of the nitric acid concentration. The energy of activation is the same than in aqueous medium. The oxidation rate of pentavalent neptunium by nitric acid is increased by nitrous acid. When no nitrous acid is added to the mixture, the reaction revealed to be autocatalytic, possesses an induction period. When nitrous and nitric acids are in excess to neptunium the reaction is first order with respect to neptunium. The reaction rate depends on the concentration of nitric acid and is a linear function of the concentration of nitrous acid. In tributyl phosphate dodecane mixtures the reaction occurs spontaneously. It is not the case in aqueous media. The values of thermodynamical and kinetical constants determined in this work could be used in a modelization of the behavior of neptunium in the reprocessing of irradiated fuels, which has to eliminate this element among its tasks [fr

Methods of Uranium Determination in solutions of Tributyl Phosphate and Kerosene

International Nuclear Information System (INIS)

Petrement Eguiluz, J.; Palomares Delgado, F.

1962-01-01

A new analytical method for the determination of uranium in organic solutions of tributyl phosphate and kerosene is proposed. In this method the uranium is reextracted from the aqueous phase by reduction with cadmium in acid solution. The uranium can be determined in this solution by the usual methods. In case of very diluted solutions, a direct spectrophtometrical determination of uranium in the organic phase with dibenzoylmethane is proposed. (Author) 21 refs

Peripheral effects of FAAH deficiency on fuel and energy homeostasis: role of dysregulated lysine acetylation.

Directory of Open Access Journals (Sweden)

Bhavapriya Vaitheesvaran

Full Text Available FAAH (fatty acid amide hydrolase, primarily expressed in the liver, hydrolyzes the endocannabinoids fatty acid ethanolamides (FAA. Human FAAH gene mutations are associated with increased body weight and obesity. In our present study, using targeted metabolite and lipid profiling, and new global acetylome profiling methodologies, we examined the role of the liver on fuel and energy homeostasis in whole body FAAH(-/- mice.FAAH(-/- mice exhibit altered energy homeostasis demonstrated by decreased oxygen consumption (Indirect calorimetry. FAAH(-/- mice are hyperinsulinemic and have adipose, skeletal and hepatic insulin resistance as indicated by stable isotope phenotyping (SIPHEN. Fed state skeletal muscle and liver triglyceride levels was increased 2-3 fold, while glycogen was decreased 42% and 57% respectively. Hepatic cholesterol synthesis was decreased 22% in FAAH(-/- mice. Dysregulated hepatic FAAH(-/- lysine acetylation was consistent with their metabolite profiling. Fasted to fed increases in hepatic FAAH(-/- acetyl-CoA (85%, p<0.01 corresponded to similar increases in citrate levels (45%. Altered FAAH(-/- mitochondrial malate dehydrogenase (MDH2 acetylation, which can affect the malate aspartate shuttle, was consistent with our observation of a 25% decrease in fed malate and aspartate levels. Decreased fasted but not fed dihydroxyacetone-P and glycerol-3-P levels in FAAH(-/- mice was consistent with a compensating contribution from decreased acetylation of fed FAAH(-/- aldolase B. Fed FAAH(-/- alcohol dehydrogenase (ADH acetylation was also decreased.Whole body FAAH deletion contributes to a pre-diabetic phenotype by mechanisms resulting in impairment of hepatic glucose and lipid metabolism. FAAH(-/- mice had altered hepatic lysine acetylation, the pattern sharing similarities with acetylation changes reported with chronic alcohol treatment. Dysregulated hepatic lysine acetylation seen with impaired FAA hydrolysis could support the liver

The investigation of antimony extraction with tributyl phosphate from nitric acid solutions

International Nuclear Information System (INIS)

Lakaev, V.S.; Smelov, V.S.

1988-01-01

Experimental data on trivalent antimony extraction with tributyl phosphate from nitric acid solutions containing (3.2-4.3)x10 -6 mol/l of antimony-125 isotope are presented. Possible mechanism of antimony (3) extraction is determined and the concentration constant for this process is calculated. Effect of temperature on the extraction of trivalent antimony is estimated. The values of enthalpy, free enthalpy and entropy are determined

Bionanocomposite films based on plasticized PLA-PHB/cellulose nanocrystal blends.

Science.gov (United States)

Arrieta, M P; Fortunati, E; Dominici, F; López, J; Kenny, J M

2015-05-05

Optically transparent plasticized poly(lactic acid) (PLA) based bionanocomposite films intended for food packaging were prepared by melt blending. Materials were plasticized with 15wt% of acetyl(tributyl citrate) (ATBC) to improve the material processability and to obtain flexibile films. Poly(hydroxybutyrate) (PHB) was used to increase PLA crystallinity. The thermal stability of the PLA-PHB blends was improved by the addition of 5 wt% of cellulose nanocrystals (CNC) or modified cellulose nanocrystals (CNCs) synthesized from microcrystalline cellulose. The combination of ATBC and cellulose nanocrystals, mainly the better dispersed CNCs, improved the interaction between PLA and PHB. Thus, an improvement on the oxygen barrier and stretchability was achieved in PLA-PHB-CNCs-ATBC which also displayed somewhat UV light blocking effect. All bionanocomposite films presented appropriate disintegration in compost suggesting their possible applications as biodegradable packaging materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

The Effect of Reactive Ionic Liquid or Plasticizer Incorporation on the Physicochemical and Transport Properties of Cellulose Acetate Propionate-Based Membranes

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Edyta Rynkowska

2018-01-01

Full Text Available Pervaporation is a membrane-separation technique which uses polymeric and/or ceramic membranes. In the case of pervaporation processes applied to dehydration, the membrane should transport water molecules preferentially. Reactive ionic liquid (RIL (3-(1,3-diethoxy-1,3-dioxopropan-2-yl-1-methyl-1H-imidazol-3-ium was used to prepare novel dense cellulose acetate propionate (CAP based membranes, applying the phase-inversion method. The designed polymer-ionic liquid system contained ionic liquid partially linked to the polymeric structure via the transesterification reaction. The various physicochemical, mechanical, equilibrium and transport properties of CAP-RIL membranes were determined and compared with the properties of CAP membranes modified with plasticizers, i.e., tributyl citrate (TBC and acetyl tributyl citrate (ATBC. Thermogravimetric analysis (TGA testified that CAP-RIL membranes as well as CAP membranes modified with TBC and ATBC are thermally stable up to at least 120 °C. Tensile tests of the membranes revealed improved mechanical properties reflected by reduced brittleness and increased elongation at break achieved for CAP-RIL membranes in contrast to pristine CAP membranes. RIL plasticizes the CAP matrix, and CAP-RIL membranes possess preferable mechanical properties in comparison to membranes with other plasticizers investigated. The incorporation of RIL into CAP membranes tuned the surface properties of the membranes, enhancing their hydrophilic character. Moreover, the addition of RIL into CAP resulted in an excellent improvement of the separation factor, in comparison to pristine CAP membranes, in pervaporation dehydration of propan-2-ol. The separation factor β increased from ca. 10 for pristine CAP membrane to ca. 380 for CAP-16.7-RIL membranes contacting an azeotropic composition of water-propan-2-ol mixture (i.e., 12 wt % water.

Extraction behavior of Nb and Ta in HF solutions with tributyl phosphate

International Nuclear Information System (INIS)

Murakami, M.; Tsuto, S.; Ooe, K.; Goto, S.; Kudo, H.; Haba, H.; Kanaya, J.

2013-01-01

Extraction behavior of carrier-free Nb and Ta with tributyl phosphate (TBP) from HF solutions was studied by a batch method. Tantalum is extracted well to an organic phase, while Nb is left in an aqueous phase at 0.053-1.0 M HF concentrations. The similar extraction trends of Nb and Ta are shown in the solid phase extraction using a TBP resin. The extraction equilibria in the solid phase extraction are attained within ∼10 s. (author)

Chromatographic assay of degradation products of tributyl phosphate

International Nuclear Information System (INIS)

Tripathi, S.C.; Ramanujam, A.; Nadkarni, M.N.; Rao, K.A.; Bandyopadhyay, C.

1985-01-01

Gas-liquid chromatography (GLC) and thin-layer chromatographic (TLC) procedures have been developed for the estimation of monobutyl phosphoric acid (H 2 MBP) and dibutyl phosphoric acid (HDBP) present in tributyl phosphate (TBP). Less than one microgram of H 2 MBP and HDBP is visually detected on TLC plate made of silicagel-cellulose (1:1). HDBP as separated by TLC has been quantitatively estimated in the range of 40-260 μg using an indirect spectrophotometric method. GLC method using 10 percent (W/W) XE-60 column can be effectively used for the simultaneous determination of 0.25 percent W/V H 2 MBP and HDBP present in 30 percent TBP-n-dodecane. The sensitivity may be enhanced 100 fold by careful column conditioning and judicious control of operational parameters. (author)

Citrate and renal calculi: an update

Science.gov (United States)

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.

Citrat og nyresten

DEFF Research Database (Denmark)

Osther, P J

1993-01-01

Citrate is an important naturally occurring inhibitor of calcium stone formation in urine. Urinary citrate excretion was examined in 43 consecutive patients with recurrent idiopathic calcium nephrolithiasis and in 50 normal controls by a specific enzymatic technique. Hypocitraturia (<1.6 mmol/24h...

Analysis of acetylation stoichiometry suggests that SIRT3 repairs nonenzymatic acetylation lesions

DEFF Research Database (Denmark)

Weinert, Brian T; Moustafa, Tarek; Iesmantavicius, Vytautas

2015-01-01

or suppresses acetylation. Using quantitative mass spectrometry, we measured acetylation stoichiometry in mouse liver tissue and found that SIRT3 suppressed acetylation to a very low stoichiometry at its target sites. By examining acetylation changes in the liver, heart, brain, and brown adipose tissue...... of fasted mice, we found that SIRT3-targeted sites were mostly unaffected by fasting, a dietary manipulation that is thought to regulate metabolism through SIRT3-dependent deacetylation. Globally increased mitochondrial acetylation in fasted liver tissue, higher stoichiometry at mitochondrial acetylation...... functions as a protein repair factor that removes acetylation lesions from lysine residues....

Thermal and mechanical properties of bio-based plasticizers mixtures on poly (vinyl chloride

Directory of Open Access Journals (Sweden)

Boussaha Bouchoul

2017-09-01

Full Text Available Abstract The use of mixtures of nontoxic and biodegradable plasticizers coming from natural resources is a good way to replace conventional phthalates plasticizers. In this study, two secondary plasticizers of epoxidized sunflower oil (ESO and epoxidized sunflower oil methyl ester (ESOME were synthesized and have been used with two commercially available biobased plasticizers; isosorbide diesters (ISB and acetyl tributyl citrate (ATBC in order to produce flexible PVC. Different mixtures of these plasticizers have been introduced in PVC formulations. Thermal, mechanical and morphological properties have been studied by using discoloration, thermogravimetric analysis (TGA, differential scanning calorimetry (DSC, dynamic mechanical thermal analysis (DMTA, tensile - strain and scanning electron microscopy (SEM. Studies have shown that PVC plasticization and stabilization were improved by addition of plasticizers blends containing ISB, ATBC, ESO and ESOME. An increase in the content of ESO or ESOME improved thermal and mechanical properties, whereas ESOME/ATBC formulations exhibited the best properties.

Plasticized poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications.

Science.gov (United States)

Arrieta, Marina Patricia; Castro-López, María del Mar; Rayón, Emilio; Barral-Losada, Luis Fernando; López-Vilariño, José Manuel; López, Juan; González-Rodríguez, María Victoria

2014-10-15

Active biobased packaging materials based on poly(lactic acid)-poly(hydroxybutyrate) (PLA-PHB) blends were prepared by melt blending and fully characterized. Catechin incorporation, as antioxidant compound, enhanced the thermal stability, whereas its release was improved by the addition of acetyl(tributyl citrate) (ATBC) as plasticizer. Whereas the incorporation of ATBC resulted in a reduction of elastic modulus and hardness, catechin addition produced more rigid materials due to hydrogen-bonding interactions between catechin hydroxyl groups and carbonyl groups of PLA and PHB. The quantification of catechin released into a fatty food simulant and the antioxidant effectiveness after the release process were demonstrated. The effect of the materials' exposure to a food simulant was also investigated. PHB-added materials maintained their structural and mechanical properties after 10 days in a test medium that represents the worst foreseeable conditions of the intended use. Thus, plasticized PLA-PHB blends with catechin show their potential as biobased active packaging for fatty food.

Acetyl coenzyme A: alpha-glucosaminide N-acetyltransferase. Evidence for a transmembrane acetylation mechanism

International Nuclear Information System (INIS)

Bame, K.J.; Rome, L.H.

1985-01-01

The lysosomal membrane enzyme acetyl-CoA: alpha-glucosaminide N-acetyltransferase catalyzes the transfer of an acetyl group from acetyl-CoA to terminal alpha-linked glucosamine residues of heparan sulfate. The reaction mechanism was examined using highly purified lysosomal membranes from rat liver. The reaction was followed by measuring the acetylation of a monosaccharide acetyl acceptor, glucosamine. The enzyme reaction was optimal above pH 5.5, and a 2-3-fold stimulation of activity was observed when the membranes were assayed in the presence of 0.1% taurodeoxycholate. Double reciprocal analysis and product inhibition studies indicated that the enzyme works by a Di-Iso Ping Pong Bi Bi mechanism. Further evidence to support this mechanism was provided by characterization of the enzyme half-reactions. Membranes incubated with acetyl-CoA and [ 3 H]CoA were found to produce acetyl-[ 3 H]CoA. This exchange was optimal at pH values above 7.0. Treating membranes with [ 3 H] acetyl-CoA resulted in the formation of an acetyl-enzyme intermediate. The acetyl group could then be transferred to glucosamine, forming [ 3 H]N-acetylglucosamine. The transfer of the acetyl group from the enzyme to glucosamine was optimal between pH 4 and 5. The results suggest that acetyl-CoA does not cross the lysosomal membrane. Instead, the enzyme is acetylated on the cytoplasmic side of the lysosome and the acetyl group is then transferred to the inside where it is used to acetylate heparan sulfate

Non-enzymatic N-acetylation of Lysine Residues by AcetylCoA Often Occurs via a Proximal S-acetylated Thiol Intermediate Sensitive to Glyoxalase II

Directory of Open Access Journals (Sweden)

Andrew M. James

2017-02-01

Full Text Available Summary: Acetyl coenzyme A (AcCoA, a key intermediate in mitochondrial metabolism, N-acetylates lysine residues, disrupting and, in some cases, regulating protein function. The mitochondrial lysine deacetylase Sirtuin 3 (Sirt3 reverses this modification with benefits reported in diabetes, obesity, and aging. We show that non-enzymatic lysine N-acetylation by AcCoA is greatly enhanced by initial acetylation of a cysteine residue, followed by SN-transfer of the acetyl moiety to a nearby lysine on mitochondrial proteins and synthetic peptides. The frequent occurrence of an S-acetyl intermediate before lysine N-acetylation suggests that proximity to a thioester is a key determinant of lysine susceptibility to acetylation. The thioesterase glyoxalase II (Glo2 can limit protein S-acetylation, thereby preventing subsequent lysine N-acetylation. This suggests that the hitherto obscure role of Glo2 in mitochondria is to act upstream of Sirt3 in minimizing protein N-acetylation, thus limiting protein dysfunction when AcCoA accumulates. : James et al. show that the non-enzymatic N-acetylation of lysine residues in mitochondrial proteins frequently occurs via a proximal S-acetylated thiol intermediate. Glutathione equilibrates with this intermediate, allowing the thioesterase glyoxalase II to limit protein lysine N-acetylation. These findings expand our understanding of how protein acetylation arises. Keywords: AcetylCoA, lysine acetylation, glyoxalase

Wet-Oxidation of Spent Organic Waste Tri-butyl Phosphate/Diluents

International Nuclear Information System (INIS)

El-Dessouky, M.I.; Abed El-Aziz, M.M.; El-Mossalamy, E.H.; Aly, H.F.

1999-01-01

Tri-Butyl Phosphate was used in reprocessing of spent nuclear fuel in the purex process. The amount of uranium retained in the organic phase depends on the type of TBP/Diluent. Destruction of spent TBP is of high interest in waste management. In the present work, oxidative degradation of TBP diluted with kerosene, carbon tetrachloride, benzene and toluene using potassium permanganate as oxidant was carried out to produce stable inorganic dry particle residue which is then immobilized in different matrices. The different factors affecting the destruction of spent waste was investigated. The up take and decontamination factor for both 152 and 154 Eu and 181 Hf and the analysis of the final product have been studied

STABILITY OF SYNTHESIZED SILVER NANOPARTICLES IN CITRATE AND MIXED GELATIN/CITRATE SOLUTION

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Jana Kavuličová

2018-04-01

Full Text Available The study focuses on an investigation of the influence of both citrate and mixed gelatin/citrate as a reductant and stabilizer on the colloidal stability of silver nanoparticles (AgNPssynthesized by a chemical reduction of Ag+ ions after a short - (7th day - and long - (118th day - term storage. Formed AgNPs were characterized by a UV–vis Spectroscopy, Transmission Electron Microscope (TEM, Dynamic light scattering (DLS and Zeta-potential (ZP. The obtained results revealed that a short-term stability of the synthesized AgNPs was greatly influenced by a citrate stabilizer with the absence of gelatin. Smaller-sized AgNPs (average particle diameter of 3 nm, roughly spherical in a shape, were obtained with a narrow size distribution. The very negative value of the Zeta-potential confirmed a strong stability of the citrate capped AgNPs. However, a surface coating of the AgNPs by a gelatin/citrate stabilizer was found to be a dominant contributor in improving a long-term stability of the AgNPs (average particle diameter of 26 nm. The use of gelatin in mixed stabilizer solution provided the AgNPs with higher monodispersity and a controllable size after both the short and long-term storage.

Acetyl-Phosphate Is a Critical Determinant of Lysine Acetylation in E. coli

DEFF Research Database (Denmark)

Weinert, Brian T; Iesmantavicius, Vytautas; Wagner, Sebastian A

2013-01-01

Lysine acetylation is a frequently occurring posttranslational modification in bacteria; however, little is known about its origin and regulation. Using the model bacterium Escherichia coli (E. coli), we found that most acetylation occurred at a low level and accumulated in growth-arrested cells...... acetylate lysine residues in vitro and that AcP levels are correlated with acetylation levels in vivo, suggesting that AcP may acetylate proteins nonenzymatically in cells. These results uncover a critical role for AcP in bacterial acetylation and indicate that most acetylation in E. coli occurs at a low...

Fluoroacetylcarnitine: metabolism and metabolic effects in mitochondria

Energy Technology Data Exchange (ETDEWEB)

Bremer, J; Davis, E J

1973-01-01

The metabolism and metabolic effects of fluoroacetylcarnitine have been investigated. Carnitineacetyltransferase transfers the fluoro-acetyl group of fluoroacetylcarnitine nearly as rapidly to CoA as the acetyl group of acetylcarnitine. Fluorocitrate is then formed by citrate synthase, but this second reaction is relatively slow. The fluorocitrate formed intramitochondrially inhibits the metabolism of citrate. In heart and skeletal muscle mitochondria the accumulated citrate inhibits citrate synthesis and the ..beta..-oxidation of fatty acids. Free acetate is formed, presumably because accumulated acetyl-CoA is hydrolyzed. In liver mitochondria the accumulation of citrate leads to a relatively increased rate of ketogenesis. Increased ketogenesis is obtained also upon the addition of citrate to the reaction mixture.

Acetylation-mediated suppression of transcription-independent memory: bidirectional modulation of memory by acetylation.

Directory of Open Access Journals (Sweden)

Katja Merschbaecher

Full Text Available Learning induced changes in protein acetylation, mediated by histone acetyl transferases (HATs, and the antagonistic histone deacetylases (HDACs play a critical role in memory formation. The status of histone acetylation affects the interaction between the transcription-complex and DNA and thus regulates transcription-dependent processes required for long-term memory (LTM. While the majority of studies report on the role of elevated acetylation in memory facilitation, we address the impact of both, increased and decreased acetylation on formation of appetitive olfactory memory in honeybees. We show that learning-induced changes in the acetylation of histone H3 at aminoacid-positions H3K9 and H3K18 exhibit distinct and different dynamics depending on the training strength. A strong training that induces LTM leads to an immediate increase in acetylation at H3K18 that stays elevated for hours. A weak training, not sufficient to trigger LTM, causes an initial increase in acetylation at H3K18, followed by a strong reduction in acetylation at H3K18 below the control group level. Acetylation at position H3K9 is not affected by associative conditioning, indicating specific learning-induced actions on the acetylation machinery. Elevating acetylation levels by blocking HDACs after conditioning leads to an improved memory. While memory after strong training is enhanced for at least 2 days, the enhancement after weak training is restricted to 1 day. Reducing acetylation levels by blocking HAT activity after strong training leads to a suppression of transcription-dependent LTM. The memory suppression is also observed in case of weak training, which does not require transcription processes. Thus, our findings demonstrate that acetylation-mediated processes act as bidirectional regulators of memory formation that facilitate or suppress memory independent of its transcription-requirement.

Non-enzymatic N-acetylation of Lysine Residues by AcetylCoA Often Occurs via a Proximal S-acetylated Thiol Intermediate Sensitive to Glyoxalase II.

Science.gov (United States)

James, Andrew M; Hoogewijs, Kurt; Logan, Angela; Hall, Andrew R; Ding, Shujing; Fearnley, Ian M; Murphy, Michael P

2017-02-28

Acetyl coenzyme A (AcCoA), a key intermediate in mitochondrial metabolism, N-acetylates lysine residues, disrupting and, in some cases, regulating protein function. The mitochondrial lysine deacetylase Sirtuin 3 (Sirt3) reverses this modification with benefits reported in diabetes, obesity, and aging. We show that non-enzymatic lysine N-acetylation by AcCoA is greatly enhanced by initial acetylation of a cysteine residue, followed by SN-transfer of the acetyl moiety to a nearby lysine on mitochondrial proteins and synthetic peptides. The frequent occurrence of an S-acetyl intermediate before lysine N-acetylation suggests that proximity to a thioester is a key determinant of lysine susceptibility to acetylation. The thioesterase glyoxalase II (Glo2) can limit protein S-acetylation, thereby preventing subsequent lysine N-acetylation. This suggests that the hitherto obscure role of Glo2 in mitochondria is to act upstream of Sirt3 in minimizing protein N-acetylation, thus limiting protein dysfunction when AcCoA accumulates. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

21 CFR 582.6195 - Calcium citrate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

21 CFR 582.5195 - Calcium citrate.

Science.gov (United States)

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... Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

21 CFR 582.1195 - Calcium citrate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.1195 Section 582.1195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is...

Structural, kinetic and proteomic characterization of acetyl phosphate-dependent bacterial protein acetylation.

Directory of Open Access Journals (Sweden)

Misty L Kuhn

Full Text Available The emerging view of Nε-lysine acetylation in eukaryotes is of a relatively abundant post-translational modification (PTM that has a major impact on the function, structure, stability and/or location of thousands of proteins involved in diverse cellular processes. This PTM is typically considered to arise by the donation of the acetyl group from acetyl-coenzyme A (acCoA to the ε-amino group of a lysine residue that is reversibly catalyzed by lysine acetyltransferases and deacetylases. Here, we provide genetic, mass spectrometric, biochemical and structural evidence that Nε-lysine acetylation is an equally abundant and important PTM in bacteria. Applying a recently developed, label-free and global mass spectrometric approach to an isogenic set of mutants, we detected acetylation of thousands of lysine residues on hundreds of Escherichia coli proteins that participate in diverse and often essential cellular processes, including translation, transcription and central metabolism. Many of these acetylations were regulated in an acetyl phosphate (acP-dependent manner, providing compelling evidence for a recently reported mechanism of bacterial Nε-lysine acetylation. These mass spectrometric data, coupled with observations made by crystallography, biochemistry, and additional mass spectrometry showed that this acP-dependent acetylation is both non-enzymatic and specific, with specificity determined by the accessibility, reactivity and three-dimensional microenvironment of the target lysine. Crystallographic evidence shows acP can bind to proteins in active sites and cofactor binding sites, but also potentially anywhere molecules with a phosphate moiety could bind. Finally, we provide evidence that acP-dependent acetylation can impact the function of critical enzymes, including glyceraldehyde-3-phosphate dehydrogenase, triosephosphate isomerase, and RNA polymerase.

Cleanup of 7.5% tributyl phosphate/n-paraffin solvent-extraction solvent

International Nuclear Information System (INIS)

Reif, D.J.

1987-02-01

The HM process at the Savannah River Plant uses 7.5% tributyl phosphate in n-paraffin as an extraction solvent. During use, the solvent is altered due to hydrolysis and radiolysis, forming materials which influence product losses, product decontamination, and separation efficiencies. Laboratory studies to improve online solvent cleaning have shown that carbonate washing, although removing residual solvent activity, does not remove binding ligands which hold fission products in the solvent. Treatment of solvent by an alumina adsorption process removes binding ligands and significantly improves recycle solvent performance. Both laboratory work defining a full-scale alumina adsorption process and the use of the process to clean HM process first cycle solvent is discussed

Separation of tributyl phosphate from degraded solvents

International Nuclear Information System (INIS)

Kumar, S.V.; Nadkarni, M.N.; Ramanujam, A.; Venkatesan, M.; Gopalakrishnan, V.; Kazi, J.A.

1977-01-01

A solvent extraction method is described for the recovery of tributyl phosphate (TBP) from degraded process solvents. The method involves the separation of TBP and shell solT(SST) from 30% TBP/SSP mixture by thorium nitrate extraction leading to the formation of a heavy phase (third phase) which contains essentially TBP. The equilibrium experiments revealed that by utilizing thorium feeds of concentrations above 525 g/L in water at 1:1 ratio, a 30% TBP/SST mixture can be effectively separated into TBP and SST fractions with light SST phase having about 3% TBP. Using single stage mixer settler experiments, the feasibility of continuous separation of the three phases was assessed. Since there is a tendency for the degraded products of the diluent to seek the TBP phase, additional treatment steps would be necessary for their removal if the TBP is to be reused. Activated charcoal was investigated for this purpose. If purification of the TBP is not envisaged the volume of the organic waste generated in processing plants could be reduced by separating the diluent and TBP and only the TBP could be sent as concentrated waste. (author)

21 CFR 184.1625 - Potassium citrate.

Science.gov (United States)

2010-04-01

... acid with potassium hydroxide or potassium carbonate. It occurs as transparent crystals or a white... 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...

Incompatibility of Contrast Medium and Trisodium Citrate

International Nuclear Information System (INIS)

Delcour, Christian; Bruninx, Guy

2013-01-01

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.

Non-enzymatic N -acetylation of Lysine Residues by AcetylCoA Often Occurs via a Proximal S -acetylated Thiol Intermediate Sensitive to Glyoxalase II

OpenAIRE

James, Andrew M.; Hoogewijs, Kurt; Logan, Angela; Hall, Andrew R.; Ding, Shujing; Fearnley, Ian M.; Murphy, Michael P.

2017-01-01

Summary: Acetyl coenzyme A (AcCoA), a key intermediate in mitochondrial metabolism, N-acetylates lysine residues, disrupting and, in some cases, regulating protein function. The mitochondrial lysine deacetylase Sirtuin 3 (Sirt3) reverses this modification with benefits reported in diabetes, obesity, and aging. We show that non-enzymatic lysine N-acetylation by AcCoA is greatly enhanced by initial acetylation of a cysteine residue, followed by SN-transfer of the acetyl moiety to a nearby lysin...

21 CFR 184.1195 - Calcium citrate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium citrate. 184.1195 Section 184.1195 Food and... 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...

N-acetyl cysteine in ovulation induction of PCOS women underwent intrauterine insemination: An RCT

Directory of Open Access Journals (Sweden)

Tahereh Behrouzi Lak

2017-08-01

Full Text Available Background: N-acetyl cysteine (NAC was proposed as an adjuvant to clomiphene citratefor ovulation induction in patients with polycystic ovary syndrome (PCOS without clomiphene citrate resistance. Objective: To evaluate the effect of NAC on pregnancy rate in PCOS patients who were candidates for intrauterine insemination. Materials and Methods: In this randomized clinical trial 97 PCOS women aged 18-38 years were enrolled in two groups, randomly. For the case group (n=49, NAC (1.2 gr+ clomiphene citrate (100 mg + letrozole (5mg were prescribed Daily from the third day of menstruation cycle for five days. The control group (n=48 had the same drug regimen without NAC. In order to follicular development, GONALF was injected on days of 7-11 menstrual cycles in all participants. When the follicle size was 18mm or more, HCG (10000 IU was injected intramuscular and the intrauterine insemination was performed after 34-36 hr. Results: There were not significant differences between study groups regarding mean endometrial thickness (p=0.14, mean number of mature follicles (p=0.20 and the pregnancy rate (p=0.09. Conclusion: NAC is ineffective in inducing or augmenting ovulation in PCOS patients who were candidates for intrauterine insemination and cannot be recommended as an adjuvant to CC in such patients.

Acetylation/deacetylation reactions of T-2, acetyl T-2, HT-2, and acetyl HT-2 toxins in bovine rumen fluid in vitro

International Nuclear Information System (INIS)

Munger, C.E.; Ivie, G.W.; Christopher, R.J.; Hammock, B.D.; Phillips, T.D.

1987-01-01

A tritiated preparation of the trichothecene mycotoxin, T-2 toxin, underwent both acetylation and deacetylation reactions when incubated with bovine rumen fluid in vitro. Products from incubations of T-2 in rumen fluid included acetyl T-2, HT-2, and acetyl HT-2. Direct studies with tritiated samples of each of these metabolites confirmed their relatively facile interconversion in the rumen. Studies with [ 3 H]HT-2 under conditions of inhibited esterase activity (added diisopropyl fluorophosphate) showed that acetylation is preferred at C-3 vs. C-4. Studies with [ 3 H]acetyl T-2 indicated that deacetylation similarly occurs with greater rapidity at C-3. There were no indications that ester hydrolysis of these trichothecenes occurred at C-8 or C-15 or that they were subjected to epoxide reduction reactions. These data suggest that acetylation of T-2 and other trichothecenes in the rumen in situ may ultimately result in the absorption of more lipophilic metabolites whose toxicological and residual properties are at present unknown

Development of plasticised nano-biocomposites of poly(hydroxybutyrate-co-hydroxyvalerate)/montmorillonite organically modified (PHBV/OMMT)

International Nuclear Information System (INIS)

Correa, M.C.; Pollet, E.; Averous, L.; Agnell, J.A.M.; Nascente, P.A.P.

2010-01-01

Several studies have aimed to improve the properties of biopolymers by the incorporation of nano-sized fillers, such as organo-modified montmorillonite (OMMT), to form nano-biocomposites. The objective of this work is to investigate the influence of acetyl tributyl citrate (ATBC) plasticizer with PHBV/OMMT nano-biocomposites aiming at improving their behavior. The materials PHBV, OMMT (C30B), and ATBC were provided by PHB Industrial S/A (Brazil), Southern Clay Products (USA), and Scandiflex S/A (Brazil), respectively. In this study the processing parameters and the formulations were controlled, pursuing materials with good mechanical and barrier properties with high biodegradability and with greater ease of processing. The analysis of the results obtained by TGA, GPC, WAXS, DSC, mechanical properties, and biodegradability lead to the conclusion that the addition of plasticizer in nanobiocomposites improved processability and did not influence the state of nano-sized load dispersion. It can be concluded that the addition of plasticizer is a good alternative to the processability of nanocomposites of PHAs. (author)

Development of plasticised nano-biocomposites of poly(hydroxybutyrate-co-hydroxyvalerate)/montmorillonite organically modified (PHBV/OMMT); Desenvolvimento de nanobiocompositos plastificados de poli(hidroxibutirato-co-hidroxivalerato)/montimorilonita organomodificada (PHBV/OMMT)

Energy Technology Data Exchange (ETDEWEB)

Correa, M.C., E-mail: nascente@ufscar.b [Universidade Federal de Sao Carlos (PPGCEM/UFSCAR), SP (Brazil). Pos-graduacao em Ciencia e Engenharia de Materiais; Pollet, E.; Averous, L. [Ecole Europeenne de Chimie, Polymeres et Materiaux (LIPHT/ECPM), Strasbourg (France). Lab. d' Ingenierie des Polymeres pour les Hautes Technologies; Agnell, J.A.M.; Nascente, P.A.P. [Universidade Federal de Sao Carlos (DEMA/UFSCAR), SP (Brazil). Dept. de Engenharia de Materiais

2010-07-01

Several studies have aimed to improve the properties of biopolymers by the incorporation of nano-sized fillers, such as organo-modified montmorillonite (OMMT), to form nano-biocomposites. The objective of this work is to investigate the influence of acetyl tributyl citrate (ATBC) plasticizer with PHBV/OMMT nano-biocomposites aiming at improving their behavior. The materials PHBV, OMMT (C30B), and ATBC were provided by PHB Industrial S/A (Brazil), Southern Clay Products (USA), and Scandiflex S/A (Brazil), respectively. In this study the processing parameters and the formulations were controlled, pursuing materials with good mechanical and barrier properties with high biodegradability and with greater ease of processing. The analysis of the results obtained by TGA, GPC, WAXS, DSC, mechanical properties, and biodegradability lead to the conclusion that the addition of plasticizer in nanobiocomposites improved processability and did not influence the state of nano-sized load dispersion. It can be concluded that the addition of plasticizer is a good alternative to the processability of nanocomposites of PHAs. (author)

Inducible transport of citrate in Lactobacillus rhamnosus ATCC 7469.

Science.gov (United States)

de Figueroa, R M; Benito de Cárdenas, I L; Sesma, F; Alvarez, F; de Ruiz Holgado, A P; Oliver, G

1996-10-01

Lactobacillus rhamnosus ATCC 7469 exhibited diauxie when grown in a medium containing both glucose and citrate as energy source. Glucose was used as the primary energy source during the glucose-citrate diauxie. Uptake of citrate was carried out by an inducible citrate transport system. The induction of citrate uptake system was repressed in the presence of glucose. This repression was reversible and mediated by cAMP.

Citrate Anticoagulation for CRRT in Children: Comparison with Heparin

Directory of Open Access Journals (Sweden)

Sara Nicole Fernández

2014-01-01

Full Text Available Regional anticoagulation with citrate is an alternative to heparin in continuous renal replacement therapies, which may prolong circuit lifetime and decrease hemorrhagic complications. A retrospective comparative cohort study based on a prospective observational registry was conducted including critically ill children undergoing CRRT. Efficacy, measured as circuit survival, and secondary effects of heparin and citrate were compared. 12 patients on CRRT with citrate anticoagulation and 24 patients with heparin anticoagulation were analyzed. Median citrate dose was 2.6 mmol/L. Median calcium dose was 0.16 mEq/kg/h. Median heparin dose was 15 UI/kg/h. Median circuit survival was 48 hours with citrate and 31 hours with heparin (P=0.028. 66.6% of patients treated with citrate developed mild metabolic alkalosis, which was directly related to citrate dose. There were no cases of citrate intoxication: median total calcium/ionic calcium index (CaT/I of 2.16 and a maximum CaT/I of 2.33, without metabolic acidosis. In the citrate group, 45.5% of patients developed hypochloremia and 27.3% hypomagnesemia. In the heparin group, 27.8% developed hypophosphatemia. Three patients were moved from heparin to citrate to control postoperatory bleeding. In conclusion citrate is a safe and effective anticoagulation method for CRRT in children and it achieves longer circuit survival than heparin.

Production of Nα-acetyl Tα1-HSA through in vitro acetylation by RimJ.

Science.gov (United States)

Chen, Jing; Li, Haibin; Wang, Tao; Sun, Shuyang; Liu, Jia; Chen, Jianhua

2017-11-10

Thymosin alpha 1 (Tα1) is an important immunomodulating agent with various clinical applications. The natural form of Tα1 is N α -acetylated, which was supposed to be related to in vivo stability of the hormone. In this study, fusion protein Tα1-HSA was constructed and expressed in Pichia pastoris . RimJ, a N α -acetyltransferase from E.coli , was also overexpressed and purified to homogeneity. In vitro acetylation of Tα1-HSA in the presence of RimJ and acetyl coenzyme A resulted in N α -acetyl Tα1-HSA. The N α -acetylation was determined by LC-MS/MS. Kinetic assay indicated that RimJ had a higher affinity to desacetyl Tα1 than to Tα1-HSA. Bioactivity assay revealed fully retained activity of Tα1 when the hormone was connected to the N-terminus of the fusion protein, while the activity was compromised in our previously constructed HSA-Tα1. With fully retained activity and N-terminal acetylation, N α -acetyl Tα1-HSA was expected to be a more promising pharmaceutical agent than Tα1.

Aspergillus niger Secretes Citrate to Increase Iron Bioavailability

Science.gov (United States)

Odoni, Dorett I.; van Gaal, Merlijn P.; Schonewille, Tom; Tamayo-Ramos, Juan A.; Martins dos Santos, Vitor A. P.; Suarez-Diez, Maria; Schaap, Peter J.

2017-01-01

Aspergillus niger has an innate ability to secrete various organic acids, including citrate. The conditions required for A. niger citrate overproduction are well described, but the physiological reasons underlying extracellular citrate accumulation are not yet fully understood. One of the less understood culture conditions is the requirement of growth-limiting iron concentrations. While this has been attributed to iron-dependent citrate metabolizing enzymes, this straightforward relationship does not always hold true. Here, we show that an increase in citrate secretion under iron limited conditions is a physiological response consistent with a role of citrate as A. niger iron siderophore. We found that A. niger citrate secretion increases with decreasing amounts of iron added to the culture medium and, in contrast to previous findings, this response is independent of the nitrogen source. Differential transcriptomics analyses of the two A. niger mutants NW305 (gluconate non-producer) and NW186 (gluconate and oxalate non-producer) revealed up-regulation of the citrate biosynthesis gene citA under iron limited conditions compared to iron replete conditions. In addition, we show that A. niger can utilize Fe(III) citrate as iron source. Finally, we discuss our findings in the general context of the pH-dependency of A. niger organic acid production, offering an explanation, besides competition, for why A. niger organic acid production is a sequential process influenced by the external pH of the culture medium. PMID:28824560

Iron(III) citrate speciation in aqueous solution.

Science.gov (United States)

Silva, Andre M N; Kong, XiaoLe; Parkin, Mark C; Cammack, Richard; Hider, Robert C

2009-10-28

Citrate is an iron chelator and it has been shown to be the major iron ligand in the xylem sap of plants. Furthermore, citrate has been demonstrated to be an important ligand for the non-transferrin bound iron (NTBI) pool occurring in the plasma of individuals suffering from iron-overload. However, ferric citrate chemistry is complicated and a definitive description of its aqueous speciation at neutral pH remains elusive. X-Ray crystallography data indicates that the alcohol function of citrate (Cit4-) is involved in Fe(III) coordination and that deprotonation of this functional group occurs upon complex formation. The inability to include this deprotonation in the affinity constant calculations has been a major source of divergence between various reports of iron(III)-citrate affinity constants. However the recent determination of the alcoholic pKa of citric acid (H4Cit) renders the reassessment of the ferric citrate system possible. The aqueous speciation of ferric citrate has been investigated by mass spectrometry and EPR spectroscopy. It was observed that the most relevant species are a monoiron dicitrate species and dinuclear and trinuclear oligomeric complexes, the relative concentration of which depends on the solution pH value and the iron : citric acid molar ratio. Spectrophotometric titration was utilized for affinity constant determination and the formation constant for the biologically relevant [Fe(Cit)2]5- is reported for the first time.

Mapping sugar beet pectin acetylation pattern.

Science.gov (United States)

Ralet, Marie-Christine; Cabrera, Juan Carlos; Bonnin, Estelle; Quéméner, Bernard; Hellìn, Pilar; Thibault, Jean-François

2005-08-01

Homogalacturonan-derived partly methylated and/or acetylated oligogalacturonates were recovered after enzymatic hydrolysis (endo-polygalacturonase+pectin methyl esterase+side-chain degrading enzymes) of sugar beet pectin followed by anion-exchange and size exclusion chromatography. Around 90% of the GalA and 75% of the acetyl groups present in the initial sugar beet pectin were recovered as homogalacturonan-derived oligogalacturonates, the remaining GalA and acetyl belonging to rhamnogalacturonic regions. Around 50% of the acetyl groups present in sugar beet homogalacturonans were recovered as partly methylated and/or acetylated oligogalacturonates of degree of polymerisation 5 whose structures were determined by electrospray ionization ion trap mass spectrometry (ESI-IT-MSn). 2-O-acetyl- and 3-O-acetyl-GalA were detected in roughly similar amounts but 2,3-di-O-acetylation was absent. Methyl-esterified GalA residues occurred mainly upstream 2-O-acetyl GalA. Oligogalacturonates containing GalA residues that are at once methyl- and acetyl-esterified were recovered in very limited amounts. A tentative mapping of the distribution of acetyl and methyl esters within sugar beet homogalacturonans is proposed. Unsubstituted GalA residues are likely to be present in limited amounts (approximately 10% of total GalA residues), due to the fact that methyl and acetyl groups are assumed to be most often not carried by the same residues.

Acetylation/deacetylation reactions of T-2, acetyl T-2, HT-2, and acetyl HT-2 toxins in bovine rumen fluid in vitro

Energy Technology Data Exchange (ETDEWEB)

Munger, C.E.; Ivie, G.W.; Christopher, R.J.; Hammock, B.D.; Phillips, T.D.

A tritiated preparation of the trichothecene mycotoxin, T-2 toxin, underwent both acetylation and deacetylation reactions when incubated with bovine rumen fluid in vitro. Products from incubations of T-2 in rumen fluid included acetyl T-2, HT-2, and acetyl HT-2. Direct studies with tritiated samples of each of these metabolites confirmed their relatively facile interconversion in the rumen. Studies with (/sup 3/H)HT-2 under conditions of inhibited esterase activity (added diisopropyl fluorophosphate) showed that acetylation is preferred at C-3 vs. C-4. Studies with (/sup 3/H)acetyl T-2 indicated that deacetylation similarly occurs with greater rapidity at C-3. There were no indications that ester hydrolysis of these trichothecenes occurred at C-8 or C-15 or that they were subjected to epoxide reduction reactions. These data suggest that acetylation of T-2 and other trichothecenes in the rumen in situ may ultimately result in the absorption of more lipophilic metabolites whose toxicological and residual properties are at present unknown.

Polarographic behaviour of uranium (VI) in tributyl phosphate organic solutions

International Nuclear Information System (INIS)

Degueldre, C.A.; Meklati, M.

1984-01-01

U(VI) determination by D.C. and differential pulse polarography was studied in the organic solutions derived from tributyl phosphate - diluent extracts (after separation from nitric acid media) along with a selected aprotic solvent (i.e.: propylene carbonate and N,N-dimethylacetamide). Miscibility of the TBP-diluent (e.g. cyclohexane, n-hexane, kerosene, n-dodecane) phase with nitric acid as supporting electrolyte, either by addition or already present in the extract was larger in DMA than in PC. In the DMA organic mixture, U(VI) exhibited a DPP peak due to a one electron step, with Esub(p)=-0.4 V (position connected with H 2 O and HNO 3 concentrations). This peak which was proportionnel to the U(VI) concentration from 5x10 -6 to 10 -3 M can be used to determinate directly hexavalent uranium in the industrial organic extraction phases TBP-diluent. (orig.)

21 CFR 522.800 - Droperidol and fentanyl citrate injection.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Droperidol and fentanyl citrate injection. 522.800... § 522.800 Droperidol and fentanyl citrate injection. (a) Specifications. Droperidol and fentanyl citrate injection is a sterile solution containing 20 milligrams of droperidol and 0.4 milligram of fentanyl citrate...

The production of rare earth elements group via tributyl phosphate extraction and precipitation stripping using oxalic acid

OpenAIRE

Jorjani, Esmaeil; Shahbazi, Malek

2016-01-01

In this study, solvent extraction and precipitation stripping were used to produce rare earth elements (REEs). Tributyl phosphate (TBP) was used to extract yttrium, lanthanum, cerium, and neodymium from an aqueous solution produced by nitric acid leaching of apatite concentrate. In the extraction stage, the effects of TBP concentration, pH, contact time, temperature, and phase ratio were investigated. The results show that about 95%, 90%, 87% and 80% of neodymium, cerium, lanthanum, and yttri...

Biotransformation of uranium and transition metal citrate complexes by clostridia

International Nuclear Information System (INIS)

Francis, A.J.; Joshi-Tope, G.A.; Dodge, C.J.; Gillow, J.B.

2002-01-01

Clostridium sphenoides, which uses citric acid as its sole carbon source, metabolized equimolar Fe(III)-citrate with the degradation of citric acid and the reduction of Fe(III) to Fe(II), but not the U(VI)-citrate complex. However, in the presence of excess citric acid or added glucose it was reduced to U(IV)-citrate. In contrast, Clostridium sp., which ferments glucose but not citrate, reduced Fe(III)-citrate to Fe(II)-citrate and U(VI)-citrate to U(IV)-citrate only when supplied with glucose. These results show that complexed uranium is readily accessible as an electron acceptor despite the bacterium's inability to metabolize the organic ligand complexed to the actinide. These results also show that the metabolism of the metal-citrate complex depends upon the type of complex formed between the metal and citric acid. Fe(III) forms a bidentate complex with citric acid and was metabolized, whereas U forms a binuclear complex with citric acid and was recalcitrant. (author)

Gallium-67 citrate localization in disseminated sporotrichosis

International Nuclear Information System (INIS)

Moreno, A.J.; Brazier, J.M.; Baker, F.J.; Fox, B.J.; Pittman, D.L.

1985-01-01

A 25-year-old woman demonstrated Ga-67 citrate accumulation within a facial cutaneous lesion and two subcutaneous nodules within the right lower extremity. Cultures of the facial lesion and one of the subcutaneous nodules grew Sporothrix schenckii. Ga-67 citrate uptake has not been reported previously with this fungal infection. Ga-67 citrate scintigraphy was helpful in defining the extent of the disease, following its course, and determining the response to therapy

Reduced Wall Acetylation Proteins Play Vital and Distinct Roles in Cell Wall O-Acetylation in Arabidopsis

DEFF Research Database (Denmark)

Manabe, Yuzuki; Verhertbruggen, Yves; Gille, Sascha

2013-01-01

The Reduced Wall Acetylation (RWA) proteins are involved in cell wall acetylation in plants. Previously, we described a single mutant, rwa2, which has about 20% lower level of O-acetylation in leaf cell walls and no obvious growth or developmental phenotype. In this study, we generated double....... The quadruple rwa mutant can be completely complemented with the RWA2 protein expressed under 35S promoter, indicating the functional redundancy of the RWA proteins. Nevertheless, the degree of acetylation of xylan, (gluco) mannan, and xyloglucan as well as overall cell wall acetylation is affected differently...... in different combinations of triple mutants, suggesting their diversity in substrate preference. The overall degree of wall acetylation in the rwa quadruple mutant was reduced by 63% compared with the wild type, and histochemical analysis of the rwa quadruple mutant stem indicates defects in cell...

Behavior of tributyl phosphate in A-line processes

International Nuclear Information System (INIS)

Harmon, H.D.; Hyder, M.L.; Tiffany, B.; Gray, L.W.; Soltys, P.A.

1976-08-01

The chemical and physical properties of uranyl nitrate--tributyl phosphate adduct (UO 2 ) (NO 3 ) 2 (TBP) 2 were studied to define optimum, safe operating conditions for denitration of uranyl nitrate (UN) solutions containing low concentrations of adduct. The distribution of TBP between aqueous UN solutions and organic phases (TBP pure or diluted in n-paraffin) was measured. Specific gravity measurements confirmed published data for aqueous UN solutions, but disagreed with literature data for 100 percent TBP. Intersection of the UN specific gravity curve and the 100 percent TBP data of this work indicated that phase inversion cannot occur when the aqueous phase contains greater than or equal to 330 g U/1. Thermal decomposition of adduct occurs in one gradual weight loss step below 170 0 C and in two successive steps above 170 0 C. Rate constants for the first reaction were calculated for 130 to 210 0 C. The major flammable decomposition product was l-butene; inorganic gases formed were N 2 , NO, N 2 O, CO, and CO 2 . Adduct decomposition during denitration of UN was characterized by foaming and by gas evolution (mostly nonflammable) at 135 to 185 0 C. Maximum flammable gas evolution and potential self-heating by TBP oxidation were calculated

Acetylation of woody lignocellulose: significance and regulation

Directory of Open Access Journals (Sweden)

Prashant Mohan-Anupama Pawar

2013-05-01

Full Text Available Non-cellulosic cell wall polysaccharides constitute approximately one quarter of usable biomass for human exploitation. In contrast to cellulose, these components are usually substituted by O-acetyl groups, which affect their properties and interactions with other polymers, thus affecting their solubility and extractability. However, details of these interactions are still largely obscure. Moreover, polysaccharide hydrolysis to constituent monosaccharides, is hampered by the presence of O-acetyl groups, necessitating either enzymatic (esterase or chemical de-acetylation, increasing the costs and chemical consumption. Reduction of polysaccharide acetyl content in planta is a way to modify lignocellulose towards improved saccharification. In this review we: 1 summarize literature on lignocellulose acetylation in different tree species, 2 present data and current hypotheses concerning the role of O-acetylation in determining woody lignocellulose properties, 3 describe plant proteins involved in lignocellulose O-acetylation, 4 give examples of microbial enzymes capable to de-acetylate lignocellulose, and 5 discuss prospects for exploiting these enzymes in planta to modify xylan acetylation.

Effect of alkaline earth metal and magnesium cations on cadmium extraction from chloride solutions by tributyl phosphate

International Nuclear Information System (INIS)

Prokuev, V.A.; Belousov, E.A.

1985-01-01

At 298 K thermodynamic constants of cadmium (2) extraction from chloride solutions of magnesium, calcium, strontium and barium by tributyl phosphate are calculated. It is established, that logarithm of the thermodynamic extraction constant is in a linear dependence from the change in the cation hydration enthalpy in agqueous solution. It is shown, that activity coefficient of neutral complex CdVCl 2 differs from one, and it is the higher the more stable the complex is in alkaline earth metal chloride solutions

Comparison of the efficiency of clomiphene citrate and letrozole in combination with metformin in moderately obese clomiphene citrate-resistant polycystic ovarian syndrome patients.

Science.gov (United States)

Bjelica, Artur; Trninić-Pjević, Aleksandra; Mladenović-Segedi, Ljiljana; Cetković, Nenad; Petrović, Djordje

2016-01-01

Polycystic ovary syndrome is the most common endocrinopathy in women of reproductive-age. Therapy for those who want to get pregnant involves ovulation induction using clomiphene citrate, metformin, letrozole and gonadotropins. The aim of the study was to compare the efficacy of combinations of clomiphene citrate-metformin and letrozole-metformin in obese patients who are resistant to clomiphene citrate alone. The investigation was conducted as a retrospective study involving 60 moderately obese patients with polycystic ovary syndrome. Thirty-one of them received the clomiphene citrate-metformin, and 29 letrozole-metformin therapy. Stimulation was carried out for the procedures of intrauterine insemination (IUI). The age of patients, duration of infertility, and body mass index in both groups were similar. There was statistically significant difference in the thickness of the endometrium in favor of the group having the letrozole-metformin therapy (8.9 ± 1.7 mm) compared with the group receiving the clomiphene citrate-metformin treatment (6.3 ± 1.3 mm). The number of follicles was not statistically significantly different. Pregnancy rate in the first cycle of IUI in the clomiphene citrate group was 6.4%, and 17.2% in the letrozole group, which also was not statistically different. After the third IUI cycle, the pregnancy rate was significantly higher in the letrozole group (20.6%), while in the clomiphene citrate group it was (9.6%). This retrospective study demonstrated the advantages of the use of letrozole over clomiphene citrate in combination with metformin in moderately obese patients with polycystic ovary syndrome who are resistant to stimulation with clomiphene citrate alone.

Enclomiphene Citrate for the Treatment of Secondary Male Hypogonadism

Science.gov (United States)

Rodriguez, Katherine M.; Pastuszak, Alexander W.; Lipshultz, Larry I.

2016-01-01

Introduction Hypogonadism is a growing concern in an aging male population. Historically treated using exogenous testosterone, concerns about possible adverse effects of testosterone have led physicians to seek alternative treatment approaches. Areas Covered Enclomiphene citrate is the trans isomer of clomiphene citrate, a non-steroidal estrogen receptor antagonist that is FDA-approved for the treatment of ovarian dysfunction in women. Clomiphene citrate has also been used off-label for many years to treat secondary male hypogonadism, particularly in the setting of male infertility. Here we review the literature examining the efficacy and safety of enclomiphene citrate in the setting of androgen deficiency. Expert Opinion Initial results support the conclusion that enclomiphene citrate increases serum testosterone levels by raising luteinizing hormone (LH) and follicle stimulating hormone (FSH) levels, without negatively impacting semen parameters. The ability to treat testosterone deficiency in men while maintaining fertility supports a role for enclomiphene citrate in the treatment of men in whom testosterone therapy is not a suitable option. PMID:27337642

2-Acetylthiamin pyrophosphate (acetyl-TPP) pH-rate profile for hydrolysis of acetyl-TPP and isolation of acetyl-TPP as a transient species in pyruvate dehydrogenase catalyzed reactions

International Nuclear Information System (INIS)

Gruys, K.J.; Datta, A.; Frey, P.A.

1989-01-01

Rate constants for the hydrolysis of acetyl-TPP were measured pH values of 2.5 and 7.5 and plotted as log k obs versus pH. The pH-rate profile defined two legs, each with a slope of +1 but separated by a region of decreased slope between pH 4 and pH 6. The rates were insensitive to buffer concentrations. Each leg of the profile reflected specific-base-catalyzed hydrolysis of acetyl-TPP, analogous to the hydrolysis of 2-acetyl-3,4-dimethylthiazolium ion. The separation of the two legs of this profile has been shown to be caused by the ionization of a group exhibiting a pK a of 4.73 within acetyl-TPP that is remote from the acetyl group, the aminopyrimidine ring, which is promoted below pH 4.73. The protonation level of this ring has been shown to control the equilibrium partitioning of acetyl-TPP among its carbinolamine, keto, and hydrate forms. The differential partitioning of these species is a major factor causing the separation between the two legs of the pH-rate profile. The characteristic pH-rate profile and the availability of synthetic acetyl-TPP have facilitated the isolation and identification of [1- 14 C]acetyl-TPP from acid-quenched enymatic reaction mixtures at steady states. [1- 14 C]Acetyl-TPP was identified as a transient species in reactions catalyzed by the PDH complex or the pyruvate dehydrogenase component of the complex (E 1 ). The pH-rate profile for hydrolysis of [1- 14 C]-acetyl-TPP, isolated from enzymatic reactions was found to be indistinguishable from that for authentic acetyl-TPP, which constituted positive identification of the 14 C-labeled enzymic species

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

Science.gov (United States)

Carneiro, Marcella Lemos Brettas; Peixoto, Raphael C A; Joanitti, Graziela A; Oliveira, Ricardo G S; Telles, Luis A M; Miranda-Vilela, Ana L; Bocca, Anamélia L; Vianna, Leonora M S; da Silva, Izabel C R; de Souza, Aparecido R; Lacava, Zulmira G M; Báo, Sônia N

2013-02-16

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. 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. 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. 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 demonstrating the therapeutic efficacy of maghemite

Synthesis and characterization of the Rhodium (II) citrate complex

International Nuclear Information System (INIS)

Najjar, R.; Santos, F.S. dos; Seidel, W.

1987-01-01

The preparation and characterization of the rhodium (II) citrate is described. Rhodium citrate was prepared by reacting citric acid trihydrated (3,4 g, 16 mmols) with anhydrous rhodium acetate (0,44 g, 1 mmol). Th electronic instruments, thermogravimetric curve and spectrum of rhodium (II) citrate are analysed. (M.J.C.) [pt

Comparison of the efficiency of clomiphene citrate and letrozole in combination with metformin in moderately obese clomiphene citrate - resistant polycystic ovarian syndrome patients

Directory of Open Access Journals (Sweden)

Bjelica Artur

2016-01-01

Full Text Available Introduction. Polycystic ovary syndrome is the most common endocrinopathy in women of reproductiveage. Therapy for those who want to get pregnant involves ovulation induction using clomiphene citrate, metformin, letrozole and gonadotropins. Objective. The aim of the study was to compare the efficacy of combinations of clomiphene citrate-metformin and letrozole-metformin in obese patients who are resistant to clomiphene citrate alone. Methods. The investigation was conducted as a retrospective study involving 60 moderately obese patients with polycystic ovary syndrome. Thirty-one of them received the clomiphene citrate-metformin, and 29 letrozole-metformin therapy. Stimulation was carried out for the procedures of intrauterine insemination (IUI. Results. The age of patients, duration of infertility, and body mass index in both groups were similar. There was statistically significant difference in the thickness of the endometrium in favor of the group having the letrozole-metformin therapy (8.9 ± 1.7 mm compared with the group receiving the clomiphene citrate-metformin treatment (6.3 ± 1.3 mm. The number of follicles was not statistically significantly different. Pregnancy rate in the first cycle of IUI in the clomiphene citrate group was 6.4%, and 17.2% in the letrozole group, which also was not statistically different. After the third IUI cycle, the pregnancy rate was significantly higher in the letrozole group (20.6%, while in the clomiphene citrate group it was (9.6%. Conclusion. This retrospective study demonstrated the advantages of the use of letrozole over clomiphene citrate in combination with metformin in moderately obese patients with polycystic ovary syndrome who are resistant to stimulation with clomiphene citrate alone.

Clomiphene citrate-induced visual hallucinations: a case report

OpenAIRE

Venkatesh, Ramesh; Gujral, Gaganjeet Singh; Gurav, Prachi; Tibrewal, Shailja; Mathur, Umang

2017-01-01

Background Polycystic ovary syndrome is a common cause of chronic anovulation and infertility in otherwise healthy fertile couples. Clomiphene citrate is used as a first-line ovulation induction therapy in patients with polycystic ovary syndrome. Clomiphene citrate can cause both systemic and ocular side effects. We report a rare side effect of illusory palinopsias in a patient with polycystic ovary syndrome treated with ovulation induction therapy with clomiphene citrate, and emphasize the n...

Preparation of lead titanate zirconate from metal citrates

International Nuclear Information System (INIS)

Bastos, C.M.R.

1994-01-01

Lead titanate zirconate (PZT) preparation from its metal constituent citrates have been investigated. Metal citrates were obtained by forced precipitation using a dehydration alcohol mixture. Salt solutions of lead nitrate and octahydrated zirconyl chloride, and titanium tetrachloride were treated separately with citric acid and ammonium hydroxide. Zirconium, titanium and lead oxides resulted from thermal decomposition of corresponding citrates at 500 0 C, 450 0 C and 250 0 C, respectively. Lead titanate (PT) and lead zirconate (P Z) were obtained by calcining at 450 0 C and 500 0 C, respectively, after adequate heating of citrates mechanically mixed in ethyl ether. PZT samples were obtained with different starting stoichiometry. Rhombohedral PZT-1 53/47 sample was prepared from co precipitating zirconyl ammonium and ammonium lead citrates in presence of ethanolic titanium oxide dispersion, and calcinating at 800 0 C. Rhombohedral PZT-q 52/48 sample was obtained from heating at 500 0 C for 2 hours a mixture of metal citrates coprecipitated by dehydration mixture of acetone-ethanol-formic acid (2:1:0,06). Tetragonal PZT-m stoichiometry 53/47 sample were obtained by calcining at after 600 0 C for 2 hours after heating a mechanically mixed metal citrates. PT phase arose at 400 0 C. PZT-m powders obtained in a range of 400 0 C-800 0 C were isostatically pressed, and sintered at 1100 0 C and 1200 0 C in saturated Pb O atmosphere. Rhombohedral sintered PZT was obtained with 7,78 g.cm -3 at 1200 0 C. (author). 123 refs, 53 figs, 32 tabs

Acetyl Fentanyl Toxicity: Two Case Reports.

Science.gov (United States)

Fort, Chelsea; Curtis, Byron; Nichols, Clay; Niblo, Cheryl

2016-11-01

Acetyl fentanyl is an illicit fentanyl analog recently appearing in forensic casework. A quantitative method was created for measuring acetyl fentanyl in various biological matrices acquired post-mortem due to recent positive screening results in casework. Initial detection by immunoassay and standard gas chromatography mass spectrometry (GC/MS) methods have been previously reported for acetyl fentanyl and are examined further here. A Selective Ion Monitoring (SIM) method was created using a GC/MS for quantitation. In two separate cases, acetyl fentanyl was found to be in similar concentrations to those previously reported and ruled to be the cause of death. Acetyl fentanyl concentrations were determined in blood samples, liver, brain, vitreous humor, and urine. Individual 1 had acetyl fentanyl concentrations as follows: heart blood-285 ng/mL, femoral blood-192 ng/mL, liver-1,100 ng/g, brain-620 ng/g, and urine-3,420 ng/mL. Individual 2 had acetyl fentanyl concentrations as follows: heart blood-210 ng/mL, femoral blood-255 ng/mL, urine-2,720 ng/mL and vitreous humor-140 ng/mL. Experimental conditions for screening and quantitation are provided, using immunoassay and GC/MS methods. Due to the recent emergence of acetyl fentanyl, more data will need to be generated to fully differentiate recreational and fatal concentrations of acetyl fentanyl to assist toxicologists accurately understanding its physiological impact. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sequential Dy(OTf)3 -Catalyzed Solvent-Free Per-O-Acetylation and Regioselective Anomeric De-O-Acetylation of Carbohydrates.

Science.gov (United States)

Yan, Yi-Ling; Guo, Jiun-Rung; Liang, Chien-Fu

2017-09-19

Dysprosium(III) trifluoromethanesulfonate-catalyzed per-O-acetylation and regioselective anomeric de-O-acetylation of carbohydrates can be tuned by adjusting the reaction medium. In this study, the per-O-acetylation of unprotected sugars by using a near-stoichiometric amount of acetic anhydride under solvent-free conditions resulted in the exclusive formation of acetylated saccharides as anomeric mixtures, whereas anomeric de-O-acetylation in methanol resulted in a moderate-to-excellent yield. Reactions with various unprotected monosaccharides or disaccharides followed by a semi-one-pot sequential conversion into the corresponding acetylated glycosyl hemiacetal also resulted in high yields. Furthermore, the obtained hemiacetals could be successfully transformed into trichloroimidates after Dy(OTf) 3 -catalyzed glycosylation. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

An active site–tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase

Energy Technology Data Exchange (ETDEWEB)

Murphy, Jesse R.; Donini, Stefano; Kappock, T. Joseph, E-mail: kappock@purdue.edu [Purdue University, 175 South University Street, West Lafayette, IN 47907-2063 (United States)

2015-09-23

Citrate synthase from the thermophilic euryarchaeon T. acidophilum fused to a hexahistidine tag was purified and biochemically characterized. The structure of the unliganded enzyme at 2.2 Å resolution contains tail–active site contacts in half of the active sites. Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that ‘close’ the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an ‘open’ structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site–tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS.

An active site–tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase

International Nuclear Information System (INIS)

Murphy, Jesse R.; Donini, Stefano; Kappock, T. Joseph

2015-01-01

Citrate synthase from the thermophilic euryarchaeon T. acidophilum fused to a hexahistidine tag was purified and biochemically characterized. The structure of the unliganded enzyme at 2.2 Å resolution contains tail–active site contacts in half of the active sites. Citrate synthase (CS) plays a central metabolic role in aerobes and many other organisms. The CS reaction comprises two half-reactions: a Claisen aldol condensation of acetyl-CoA (AcCoA) and oxaloacetate (OAA) that forms citryl-CoA (CitCoA), and CitCoA hydrolysis. Protein conformational changes that ‘close’ the active site play an important role in the assembly of a catalytically competent condensation active site. CS from the thermoacidophile Thermoplasma acidophilum (TpCS) possesses an endogenous Trp fluorophore that can be used to monitor the condensation reaction. The 2.2 Å resolution crystal structure of TpCS fused to a C-terminal hexahistidine tag (TpCSH6) reported here is an ‘open’ structure that, when compared with several liganded TpCS structures, helps to define a complete path for active-site closure. One active site in each dimer binds a neighboring His tag, the first nonsubstrate ligand known to occupy both the AcCoA and OAA binding sites. Solution data collectively suggest that this fortuitous interaction is stabilized by the crystalline lattice. As a polar but almost neutral ligand, the active site–tail interaction provides a new starting point for the design of bisubstrate-analog inhibitors of CS

Hemodiafiltration using pre-dilutional on-line citrate dialysate: A new technique for regional citrate anticoagulation: A feasibility study

Directory of Open Access Journals (Sweden)

Radhouane Bousselmi

2015-01-01

Full Text Available A prospective, observational, feasibility study was carried out on four patients with end-stage renal failure undergoing bicarbonate hemodialysis to study the feasibility of an on-line hemodiafiltration technique using a citrate dialysate with pre-dilutional infusion of citrate as a technique for regional citrate anticoagulation. All patients had contraindication to systemic heparin anticoagulation. The dialysis technique consisted of an on-line hemodiafiltration with a citrate dialysate without calcium using a Fresenius 4008S dialysis machine and Fresenius Polysulfone F60 dialyzers. The infusion solution was procured directly from the dialysate and was infused into the arterial line. To avoid the risk of hypocalcemia, calcium gluconate was infused to the venous return line. The study was carried out in two stages. During the first stage, the citrate infusion rate was 80 mL/min and the calcium infusion rate was 9 mmol/h. At the second stage, the rates were 100 mL/min and 11 mmol/h, respectively. The primary endpoint of this study was the incidence of thrombosis in the extracorporeal blood circuit and/or the dialyzer. A total of 78 sessions were conducted. All the sessions were well tolerated clinically and there were no major incidents in any of the four patients. At the first stage of the study, there were five incidences of small clots in the venous blood chamber, an incidence of extracorporeal blood circuit thrombosis of 12.5%. At the second stage of the study, no cases of extracorporeal blood circuit or dialyzer thrombosis were noted. Hemodiafiltration with on-line citrate dialysate infusion to the arterial line is safe and allows an effective regional anticoagulation of the extracorporeal blood circuit without the need for systemic anticoagulation.

Separation of lanthanum (3) and neodymium (3) by tributyl phosphate extraction in the presence of solid phase

International Nuclear Information System (INIS)

Korotkevich, I.B.; Kolesnikov, A.A.; Bomshtejn, V.E.; Shikhaleeva, N.N.

1987-01-01

Lanthanum (3) and neodymium (3) extraction from nitric acid solutions by tributyl phosphate in the presence of solid phase of the element nitrates is investigated. An increase in distribution of neodymium nitrate in the presence of solid phase with the decrease in its concentration in the initial solution and with the increase in lanthanum nitrate concentration is detected. The highest effect of extractive-crystallizational separation is observed in the range of neodymium nitrate microconcentrations. A method of neodymium quantitative extraction from lanthanum nitrate solutions with neodymium - lanthanum separation coefficient exceeding 25 is suggested

Citrate and succinate uptake by potato mitochondria

International Nuclear Information System (INIS)

Jung, D.W.; Laties, G.G.

1979-01-01

Potato mitochondria, in the absence of respiration, have a very low capacity for uptake by exchange with endogenous anions, taking up only 2.4 nanomoles citrate and 2.0 nanomoles succinate per milligram protein. Maximum citrate uptake of over 17 nanomoles per milligram protein occurs in the presence of inorganic phosphate, a dicarboxylic acid, and an external energy source (NADH), conditions where net anion accumulation proceeds, mediated by the interlinking of the inorganic phosphate, dicarboxylate, and tricarboxylate carriers. Maximum succinate uptake in the absence of respiratory inhibitors requires only added inorganic phosphate. Compounds which inhibit respiration (antimycin), the exchange carriers (mersalyl and benzylmalonate), or the establishment of the membrane proton motive force (uncouplers) reduce substrate accumulation. A potent inhibitor of the citrate carrier in animal mitochondria, 1,2,3-benzenetricarboxylic acid, does not inhibit citrate uptake in potato mitochondria. Citrate uptake is reduced by concurrent ADP phosphorylation and this reduction is sensitive to oligomycin. The initiation of state 3 after a 3-minute substrate state results in a reduction of the steady-state of citrate uptake by approximately 50%. Accumulation of succinate initially is inhibited by increasing sucrose concentration in the reaction medium from 50 to 400 millimolar. Limited substrate uptake is one of the factors responsible for the often observed depressed initial state 3 respiration rates in many mitochondrial preparations. Since nonlimiting levels of substrate in the matrix cannot be attained by energy-independent exchange, a dependence on respiration for adequate uptake results. Substrate limitation therefore occurs in the matrix for the period of time needed for energy-dependent accumulation of nonlimiting levels

A test of the citrate method of PMI estimation from skeletal remains.

Science.gov (United States)

Wilson, Sarah J; Christensen, Angi M

2017-01-01

Citrate content in bone has been shown to be associated with the postmortem interval (PMI), with citrate decreasing after death as a function of time. Here we test this method using porcine ribs for the period of 1-165days after death, and also assess citrate content and variation from samples placed into two different postmortem environments (terrestrial and aquatic). Higher citrate variation, lower citrate recovery, and a weaker association with time were found in this study as compared to others. Citrate content, however, was found to decrease with increasing PMI, and the method was found to be easy and inexpensive to apply. No significant differences were found in citrate loss between terrestrial and aquatic environments. Although more research is needed, citrate content appears to be a promising new approach in estimating PMI from skeletal remains. Published by Elsevier B.V.

FERRIC CITRATE: AN IRON-BASED ORAL PHOSPHATE BINDER

Directory of Open Access Journals (Sweden)

T. Christopher Bond

2012-06-01

Based on actual physician behavior in response to ferritin and TSAT increases and ferric citrate clinical trial results, and assuming equivalent pricing to other PBs, there would be cost savings with ferric citrate use through reduced ESA and iron use.

Preparation of electrocatalysts by reduction of precursors with sodium citrate

OpenAIRE

Briskeby, Stein Trygve; Tsypkin, Mikhail; Tunold, Reidar; Sunde, Svein

2014-01-01

In this work synthesis of Pt/C catalysts by reduction of H2PtCl6 with sodium citrate has been investigated. The strong pH-dependence of citrate as a reducing and stabilizing agent has been explored, and an optimum pH range for production of well dispersed catalysts is proposed. To achieve stabilizing and reducing conditions, the presence of both citrate anions and protonated citrates are required. This is achieved in an intermediate pH range between pKa2 and pKa3 (4.76 and 6.4) of citric acid...

Acetylation of Mammalian ADA3 Is Required for Its Functional Roles in Histone Acetylation and Cell Proliferation.

Science.gov (United States)

Mohibi, Shakur; Srivastava, Shashank; Bele, Aditya; Mirza, Sameer; Band, Hamid; Band, Vimla

2016-10-01

Alteration/deficiency in activation 3 (ADA3) is an essential component of specific histone acetyltransferase (HAT) complexes. We have previously shown that ADA3 is required for establishing global histone acetylation patterns and for normal cell cycle progression (S. Mohibi et al., J Biol Chem 287:29442-29456, 2012, http://dx.doi.org/10.1074/jbc.M112.378901). Here, we report that these functional roles of ADA3 require its acetylation. We show that ADA3 acetylation, which is dynamically regulated in a cell cycle-dependent manner, reflects a balance of coordinated actions of its associated HATs, GCN5, PCAF, and p300, and a new partner that we define, the deacetylase SIRT1. We use mass spectrometry and site-directed mutagenesis to identify major sites of ADA3 acetylated by GCN5 and p300. Acetylation-defective mutants are capable of interacting with HATs and other components of HAT complexes but are deficient in their ability to restore ADA3-dependent global or locus-specific histone acetylation marks and cell proliferation in Ada3-deleted murine embryonic fibroblasts (MEFs). Given the key importance of ADA3-containing HAT complexes in the regulation of various biological processes, including the cell cycle, our study presents a novel mechanism to regulate the function of these complexes through dynamic ADA3 acetylation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Acetylation dynamics and stoichiometry in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Weinert, Brian Tate; Iesmantavicius, Vytautas; Moustafa, Tarek

2014-01-01

Lysine acetylation is a frequently occurring posttranslational modification; however, little is known about the origin and regulation of most sites. Here we used quantitative mass spectrometry to analyze acetylation dynamics and stoichiometry in Saccharomyces cerevisiae. We found that acetylation...

Development of a flexible and bendable vibrotactile actuator based on wave-shaped poly(vinyl chloride)/acetyl tributyl citrate gels for wearable electronic devices

Science.gov (United States)

Park, Won-Hyeong; Bae, Jin Woo; Shin, Eun-Jae; Kim, Sang-Youn

2016-11-01

The paradigm of consumer electronic devices is being shifted from rigid hand-held devices to flexible/wearable devices in search of benefits such as enhanced usability and portability, excellent wear characteristics, and more functions in less space. However, the fundamental incompatibility of flexible/wearable devices and a rigid actuator brought forth a new issue obstructing commercialization of flexible/wearable devices. In this paper, we propose a new wave-shaped eco-friendly PVC gel, and a new flexible and bendable vibrotactile actuator that could easily be applied to wearable electronic devices. We explain the vibration mechanism of the proposed vibrotactile actuator and investigate its influence on the content of plasticizer for the performance of the proposed actuator. An experiment for measuring vibrational amplitude was conducted over a wide frequency range. The experiment clearly showed that the proposed vibrotactile actuator could create a variety of haptic sensations in wearable devices.

Acetylation and characterization of banana (Musa paradisiaca) starch.

Science.gov (United States)

Bello-Pérez, L A; Contreras-Ramos, S M; Jìmenez-Aparicio, A; Paredes-López, O

2000-01-01

Banana native starch was acetylated and some of its functional properties were evaluated and compared to corn starch. In general, acetylated banana starch presented higher values in ash, protein and fat than corn acetylated starch. The modified starches had minor tendency to retrogradation assessed as % transmittance of starch pastes. At high temperature acetylated starches presented a water retention capacity similar to their native counterpart. The acetylation considerably increased the solubility of starches, and a similar behavior was found for swelling power. When freeze-thaw stability was studied, acetyl banana starch drained approximately 60% of water in the first and second cycles, but in the third and fourth cycles the percentage of separated water was low. However, acetyl corn starch showed lower freeze-thaw stability than the untreated sample. The modification increased the viscosity of banana starch pastes.

Characterization and mode of action of two acetyl xylan esterases from Chrysosporium lucknowense C1 active towards acetylated xylans

NARCIS (Netherlands)

Pouvreau, L.A.M.; Jonathan, M.C.; Kabel, M.A.; Hinz, S.W.A.; Gruppen, H.; Schols, H.A.

2011-01-01

Two novel acetyl xylan esterases, Axe2 and Axe3, from Chrysosporium lucknowense (C1), belonging to the carbohydrate esterase families 5 and 1, respectively, were purified and biochemically characterized. Axe2 and Axe3 are able to hydrolyze acetyl groups both from simple acetylated

p53 Acetylation: Regulation and Consequences

International Nuclear Information System (INIS)

Reed, Sara M.; Quelle, Dawn E.

2014-01-01

Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer

p53 Acetylation: Regulation and Consequences

Energy Technology Data Exchange (ETDEWEB)

Reed, Sara M. [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Quelle, Dawn E., E-mail: dawn-quelle@uiowa.edu [Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Medical Scientist Training Program, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States); Department of Pathology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242 (United States)

2014-12-23

Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.

Whole-body retention studies of /sup 167/Tm--citrate. Estimation of radiation dose to humans from /sup 167/Tm--citrate

Energy Technology Data Exchange (ETDEWEB)

Hiraki, T; Ando, A [Kanazawa Univ. (Japan). School of Paramedicine; Mori, H; Ando, I; Sakamoto, K

1978-02-01

For the purpose of calculating absorbed dose to humans from /sup 167/Tm-citrate, the whole-body retention studies using 5 rats were carried out. Up to 40 days following intravenous injection of /sup 167/Tm-citrate, the whole-body counts were monitored with an animal counter. The whole-body retention curve was obtained with three exponential components. Namely, the 26% of the injected /sup 167/Tm-citrate had a biological half-time of 3.4 hours, 12.5% had a biological half-time of 99 hours and 61.5% had a biological half-time of 106 days. These results indicate, that three components consist of the rapid clearance from the kidneys, the retention in the liver and other soft tissues with relatively long half-time and the retention in the bones with long half-time. Based on these biological data and the MIRD Committee method, the average dose estimates to the bone and whole-body from intravenous administration of 1 mCi /sup 167/Tm-citrate were 7.08 rads and 1.28 rads, respectively.

NetAcet: prediction of N-terminal acetylation sites

DEFF Research Database (Denmark)

Kiemer, Lars; Bendtsen, Jannick Dyrløv; Blom, Nikolaj

2005-01-01

Summary: We present here a neural network based method for prediction of N-terminal acetylation-by far the most abundant post-translational modification in eukaryotes. The method was developed on a yeast dataset for N-acetyltransferase A (NatA) acetylation, which is the type of N-acetylation for ......Summary: We present here a neural network based method for prediction of N-terminal acetylation-by far the most abundant post-translational modification in eukaryotes. The method was developed on a yeast dataset for N-acetyltransferase A (NatA) acetylation, which is the type of N...

Is it safe to prescribe clomiphene citrate without ultrasound monitoring facilities?

LENUS (Irish Health Repository)

Coughlan, C

2010-05-01

The majority of triplet and higher order multiple pregnancies now result from ovulation induction\\/superovulation rather than in vitro fertilisation. However, clomiphene citrate is still widely prescribed by gynaecologists and general practitioners who do not have access to ultrasound monitoring. The objective of our study was to determine the prevalence of multifollicular development with different doses of clomiphene citrate. A retrospective review of transvaginal ultrasound monitoring of 425 cycles in 182 women receiving clomiphene citrate from January 2002 to December 2003, was studied. Three or more follicles of >or= 14 mm were identified in 58 cycles (14%). Patients received 50 mg of clomiphene citrate in 52 of these 58 cycles and 25 mg in the remaining six. One patient was noted to have developed five follicles and 10 patients developed four follicles. One patient developed six follicles, despite receiving only 25 mg clomiphene citrate daily. It was concluded that a significant number of women (14%) developed three or more follicles, despite receiving low doses of clomiphene citrate.

Effect of Drying Pretreatment on the Acetylation of Nanofibrillated Cellulose

Directory of Open Access Journals (Sweden)

Vesna Zepič

2015-10-01

Full Text Available The aim of this study was to evaluate the effect of different morphologies of solvent-exchanged (NFCSE, spray-dried (NFCSD, and freeze-dried (NFCFD nano-fibrillated cellulose on the susceptibility to surface modification with the acetic anhydride/pyridine system. The degree of substitution (DS, morphology, degree of crystallinity (Icr, hydrophobicity, and thermal stability of acetylated products were examined. Acetylated NFCSD and NFCFD had higher DS than acetylated NFCSE, suggesting that drying pre-treatment increased the susceptibility of NFC for acetylation. The morphology of acetylated NFCFD and NFCSD with higher DS was different from unmodified samples, while that of NFCSE was not affected by acetylation. Microspheres of acetylated NFCSD started to dissolve when the highest DS was reached. As opposed to unmodified NFCFD, the nanofibrillar units of acetylated NFCFD became individualised at lower DS. Acetylated samples had lower Icr than the unmodified samples. A significant increase in the contact angle was observed at higher DS of acetylated NFC samples. Acetylation markedly elevated the thermal stability of the acetylated NFC samples.

Citrate-Induced Nanocubes: A Re-Examination of the Role of Citrate as a Shape-Directing Capping Agent for Ag-Based Nanostructures.

Science.gov (United States)

Hajfathalian, Maryam; Gilroy, Kyle D; Hughes, Robert A; Neretina, Svetlana

2016-07-01

Seed-mediated syntheses utilizing facet-selective surface passivation provide the necessary chemical controls to direct noble metal nanostructure formation to a predetermined geometry. The foremost protocol for the synthesis of (111)-faceted Ag octahedra involves the reduction of metal ions onto pre-existing seeds in the presence of citrate and ascorbic acid. It is generally accepted that the capping of (111) facets with citrate dictates the shape while ascorbic acid acts solely as the reducing agent. Herein, a citrate-based synthesis is demonstrated in which the presence or absence of ascorbic acid is the shape-determining factor. Reactions are carried out in which Ag(+) ions are reduced onto substrate-immobilized Ag, Au, Pd, and Pt seeds. Syntheses lacking ascorbic acid, in which citrate acts as both the capping and the reducing agent, result in a robust nanocube growth mode able to withstand wide variations in the concentration of reactants, reaction rates, seed material, seed orientation and faceting, pH, and substrate material. If, however, ascorbic acid is included in these syntheses, then the growth mode reverts to one that advances the octahedral geometry. The implication of these results is that citrate, or one of its oxidation products, selectively caps (100) facets, but where this capability is compromised by ascorbic acid. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Citrate Anticoagulation during Continuous Renal Replacement Therapy.

Science.gov (United States)

Ricci, Davide; Panicali, Laura; Facchini, Maria Grazia; Mancini, Elena

2017-01-01

During extracorporeal dialysis, some anticoagulation strategy is necessary to prevent the coagulation of blood. Heparin has historically been used as an anticoagulant because of its efficacy combined with low cost. However, a variable incidence of hemorrhagic complications (5-30%) has been documented in patients undergoing continuous renal replacement therapy (CRRT) with heparin as an anticoagulant. Citrate has anticoagulation properties secondary to its ability to chelate calcium, which is necessary for the coagulation cascade. Citrate may thus be used in a regional anticoagulation (RCA), limited to the extracorporeal circuit of CRRT, to avoid systemic anticoagulation. Recent meta-analysis confirmed the advantage of RCA over heparin in terms of incidence of bleeding during CRRT. Moreover, an increase in filter lifespan is documented, with a secondary advantage in reaching the prescribed dialysis dose. In our experience, we could confirm this positive effect. In fact, with a progressive increase in the proportion of CRRT with citrate as RCA, we obtained a reduction in the number of filters used for every 72 h of treatment (from 2.4 in 2011 to 1.3 in 2015), and most importantly, a reduction in the difference between the prescribed and delivered dialysis doses (from 22 to 7%). Citrate has an intense effect on the acid-base balance as well, if fully metabolized through the Krebs cycle, due to the production of bicarbonate. Even more severely ill patients, such as those with liver dysfunction, may be treated with RCA without severe complications, because modern machines for CRRT are equipped with simple systems that are able to manage the citrate infusion and control the calcium levels, with minimal risks of metabolic derangements. © 2017 S. Karger AG, Basel.

Impact of a short-term exposure to tributyl phosphate on morphology, physiology and migratory behaviour of European eels during the transition from freshwater to the marine environment

DEFF Research Database (Denmark)

Privitera, Lucia; Aarestrup, Kim; Moore, Andy

2013-01-01

Migrating silver European eels were exposed for 5 days in a laboratory to an environmental level of tributyl phosphate (TBP), tagged with acoustic transmitters and released below the Tange hydropower station, on the River Gudenaa, Denmark. The subsequent movements of the eels were monitored as th...

Extraction And Separation Of GALLIUM With Tributyl Phosphate From The Chloride Leach Liquor Of GATTAR Granite, Eastern Desert, Egypt

International Nuclear Information System (INIS)

MAHDY, M.A.; MAHMOUD, K.F.; ABD EL-HAMEED, A.M.; ZAHRAN, M.A.

2009-01-01

The studied optimum conditions for gallium extraction have confirmed that more than 98.5% of the gallium present in HCl leach liquor of Gattar granite was extracted using 10 % tributyl phosphate (TBP) solvent concentration (v/v) in kerosene as diluent, 15 min shaking time and 1 : 3 organic/ aqueous ratio. About 96 % of the extracted gallium has been stripped from the organic solvent using 0.04 M HCl as aqueous stripping solution. The obtained data clarify that the optimum stripping conditions include 4 min shaking time and 2 : 1 organic/ aqueous ratio.

Trichoderma reesei CE16 acetyl esterase and its role in enzymatic degradation of acetylated hemicellulose

DEFF Research Database (Denmark)

Biely, Peter; Cziszarava, Maria; Agger, Jane W.

2014-01-01

Results The combined action of GH10 xylanase and acetylxylan esterases (AcXEs) leads to formation of neutral and acidic xylooligosaccharides with a few resistant acetyl groups mainly at their non-reducing ends. We show here that these acetyl groups serve as targets for TrCE16 AcE. The most promin...

Purification and properties of an O-acetyl-transferase from Escherichia coli that can O-acetylate polysialic acid sequences

International Nuclear Information System (INIS)

Higa, H.; Varki, A.

1986-01-01

Certain strains of bacteria synthesize an outer polysialic acid (K1) capsule. Some strains of K1 + E.coli are also capable of adding O-acetyl-esters to the exocyclic hydroxyl groups of the sialic acid residues. Both the capsule and the O-acetyl modification have been correlated with differences in antigenicity and pathogenicity. The authors have developed an assay for an O-acetyl-transferase in E.coli that transfers O-[ 3 H]acetyl groups from [ 3 H]acetyl-Coenzyme A to colominic acid (fragments of the polysialic acid capsule). Using this assay, the enzyme was solubilized, and purified ∼ 600-fold using a single affinity chromatography step with Procion Red-A Agarose. The enzyme also binds to Coenzyme A Sepharose, and can be eluted with high salt or Coenzyme A. The partially purified enzyme has a pH optimum of 7.0 - 7.5, is unaffected by divalent cations, is inhibited by high salt concentrations, is inhibited by Coenzyme A (50% inhibition at 100 μM), and shows an apparent Km for colominic acid of 3.7 mM (sialic acid concentration). This enzyme could be involved in the O-acetyl +/- form variation seen in some strains of K1 + E.coli

Differential patterns of histone acetylation in inflammatory bowel diseases

Directory of Open Access Journals (Sweden)

Adcock Ian M

2011-01-01

Full Text Available Abstract Post-translational modifications of histones, particularly acetylation, are associated with the regulation of inflammatory gene expression. We used two animal models of inflammation of the bowel and biopsy samples from patients with Crohn's disease (CD to study the expression of acetylated histones (H 3 and 4 in inflamed mucosa. Acetylation of histone H4 was significantly elevated in the inflamed mucosa in the trinitrobenzene sulfonic acid model of colitis particularly on lysine residues (K 8 and 12 in contrast to non-inflamed tissue. In addition, acetylated H4 was localised to inflamed tissue and to Peyer's patches (PP in dextran sulfate sodium (DSS-treated rat models. Within the PP, H3 acetylation was detected in the mantle zone whereas H4 acetylation was seen in both the periphery and the germinal centre. Finally, acetylation of H4 was significantly upregulated in inflamed biopsies and PP from patients with CD. Enhanced acetylation of H4K5 and K16 was seen in the PP. These results demonstrate that histone acetylation is associated with inflammation and may provide a novel therapeutic target for mucosal inflammation.

Risks and benefits of citrate anticoagulation for continuous renal replacement therapy.

Science.gov (United States)

Shum, H P; Yan, W W; Chan, T M

2015-04-01

Heparin, despite its significant side-effects, is the most commonly used anticoagulant for continuous renal replacement therapy in critical care setting. In recent years, citrate has gained much popularity by improving continuous renal replacement therapy circuit survival and decreasing blood transfusion requirements. However, its complex metabolic consequences warrant modification in the design of the citrate-based continuous renal replacement therapy protocol. With thorough understanding of the therapeutic mechanism of citrate, a simple and practicable protocol can be devised. Citrate-based continuous renal replacement therapy can be safely and widely used in the clinical setting with appropriate clinical staff training.

Functional Characterization of ATM Kinase Using Acetylation-Specific Antibodies.

Science.gov (United States)

Sun, Yingli; Du, Fengxia

2017-01-01

The activation of ATM is critical in the DNA double strand breaks repair pathway. Acetylation of ATM by Tip60 histone acetyltransferase (HAT) plays a key role in the activation of ATM kinase activity in response to DNA damage. ATM forms a stable complex with Tip60 through the FATC domain of ATM. Tip60 acetylates lysine3016 of ATM, and this acetylation induces the activation of ATM. Several techniques are included in the study of ATM acetylation by Tip60, such as in vitro kinase assay, systematic mutagenesis, western blots. Here, we describe how to study the acetylation of ATM using acetylation-specific antibodies.

Alkali replacement raises urinary citrate excretion in patients with topiramate-induced hypocitraturia.

Science.gov (United States)

Jhagroo, R Allan; Wertheim, Margaret L; Penniston, Kristina L

2016-01-01

The aims of this study were to assess (1) the magnitude and temporality of decreased urinary citrate excretion in patients just starting topiramate and (2) the effect of alkali replacement on topiramate-induced hypocitraturia. Study 1 was a prospective, non-intervention study in which patients starting topiramate for headache remediation provided pre- and post-topiramate 24 h urine collections for measurement of urine citrate. Study 2 was a clinical comparative effectiveness study in which patients reporting to our stone clinic for kidney stones and who were treated with topiramate were prescribed alkali therapy. Pre- and post-alkali 24 h urinary citrate excretion was compared. Data for 12 and 22 patients (studies 1 and 2 respectively) were evaluated. After starting topiramate, urinary citrate excretion dropped significantly by 30 days (P = 0.016) and 62% of patients had hypocitraturia (citrate alkali, urine citrate increased in stone-forming patients on topiramate (198 ± 120 to 408 ± 274 mg day(-1) ; P = 0.042 for difference). 85% of patients were hypocitraturic on topiramate alone vs. 40% after adding alkali. The increase in urinary citrate was greater in patients provided ≥ 90 mEq potassium citrate. Our study is the first to provide clinical evidence that alkali therapy can raise urinary citrate excretion in patients who form kidney stones while being treated with topiramate. Clinicians should consider alkali therapy for reducing the kidney stone risk of patients benefitting from topiramate treatment for migraine headaches or other conditions. © 2015 The British Pharmacological Society.

Sildenafil citrate (Viagra) enhances vasodilatation in fetal growth restriction.

Science.gov (United States)

Wareing, Mark; Myers, Jenny E; O'Hara, Maureen; Baker, Philip N

2005-05-01

Fetal growth restriction (FGR) affects up to 8% of all pregnancies and has massive short-term (increased fetal morbidity and mortality) and long-term (increased incidence of cardiovascular disease in adulthood) health implications. Doppler waveform analysis of pregnancies complicated by FGR suggests compromised uteroplacental circulation and placental hypoperfusion. Our aim was to determine whether myometrial small artery function was aberrant in FGR and to assess whether sildenafil citrate could improve vasodilatation in FGR pregnancies. Small arteries dissected from myometrial biopsies obtained at cesarean section from normal pregnant women (n = 27) or women whose pregnancies were complicated by FGR (n = 12) were mounted on wire myographs. Vessels were constricted (with arginine vasopressin or U46619) and relaxed (with bradykinin) before and after incubation with a phosphodiesterase-5 inhibitor, sildenafil citrate. We demonstrated increased myometrial small artery vasoconstriction and decreased endothelium-dependent vasodilatation in vessels from women whose pregnancies were complicated by FGR. Sildenafil citrate significantly reduced vasoconstriction and significantly improved relaxation of FGR small arteries. We conclude that sildenafil citrate improves endothelial function of myometrial vessels from women whose pregnancies are complicated by intrauterine growth restriction. Sildenafil citrate may offer a potential therapeutic strategy to improve uteroplacental blood flow in FGR pregnancies.

Study of Np speciation in citrate medium

Energy Technology Data Exchange (ETDEWEB)

Bonin, L.; Den Auwer, C.; Ansoborlo, E.; Moisy, P. [CEA Valrho - DEN/DRCP/SCPS, Bagnols sur Ceze (France); Cote, G. [ENSP - LECA, UMR 7575, Paris (France)

2007-07-01

In the framework of the French Environmental Nuclear Toxicology program, additional experiments related to the decorporation of actinides are planned. Decorporation is the removal or release from target organs (bones, liver, kidney..), tissues or cells of radioactive material previously incorporated in them, using chelating agents or other administrated pharmaceutical agents. The contradictory data on the neptunium complexation behaviour within blood and its transfer to target organs, as well as the inefficiency of therapeutic treatments, led us to study the complexation of this element with biological constituents. Within this purpose, the in vitro behaviour of Np(IV) and Np(V) in simple media simulating biological fluids was studied. This study was more specifically focused on the behaviour of neptunium with citrate ion, which is an essential component in a number of metalloenzyme active sites. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np(V) with various acido-basic forms of the citrate anion was observed; regarding Np(IV), complexes with Cit{sup 3-} have been observed. From the quantitative study of these equilibria, the values of the absolute constants for the complexation of Np(IV) and Np(V) with citrate were determined. Concerning the stability of neptunium towards oxydo-reduction, it was confirmed that Np(VI) was very quickly reduced to Np(V) by the citrate anions, whereas Np(IV) was stable. In the case of Np(V), it was observed that, depending on the pH and the citrate concentration, Np(V) was unstable and was reduced to Np(IV). The E-pH diagrams, constructed using the stability constants determined in this study, showed that this instability was due to the Np(V) disproportionation. (orig.)

Studies investigating the excretion of acetyl urea in the milk of dairy cows receiving oral doses of 14C acetyl urea

International Nuclear Information System (INIS)

Bergner, H.; Kijora, C.; Goersch, R.

1976-01-01

2 experimental cows were fed acetyl urea several weeks before the trial was started. The first cow received a daily amount of 200 g and the second cow 855 g. On the first day of experiment both cows were given 5 mCi of 14 C acetyl urea intraruminally. Up to 6 hrs after the beginning of the experiment acetyl urea in blood plasma was shown to contain a higher proportion of 14 C activity than urea. 0.21 g urea and 0.18 g acetyl urea were contained in 1 kg of milk from cow No 1 while 1 kg of milk from cow No 2 contained 0.18 g urea and 0.12 g acetyl urea. The feeding of acetyl urea to dairy cows is not recommended on the basis of the fact that any further contamination of human nutrition with foreign substances should be possibly avoided. (author)

Discovery and characterization of Ku acetylation in Mycobacterium smegmatis.

Science.gov (United States)

Zhou, Ying; Chen, Tao; Zhou, Lin; Fleming, Joy; Deng, Jiaoyu; Wang, Xude; Wang, Liwei; Wang, Yingying; Zhang, Xiaoli; Wei, Wenjing; Bi, Lijun

2015-03-01

Lysine acetylation is an important post-translational modification and is known to regulate many eukaryotic cellular processes. Little, however, is known about acetylated proteins in prokaryotes. Here, using immunoblotting, mass spectrometry and mutagenesis studies, we investigate the acetylation dynamics of the DNA repair protein Ku and its relationship with the deacetylase protein Sir2 and the non-homologous end joining (NHEJ) pathway in Mycobacterium smegmatis. We report that acetylation of Ku increases with growth, while NHEJ activity decreases, providing support for the hypothesis that acetylation of Ku may be involved in the DNA damage response in bacteria. Ku has multiple lysine sites. Our results indicate that K29 is an important acetylation site and that deficiency of Sir2 or mutation of K29 affects the quantity of Ku and its acetylation dynamics. Our findings expand knowledge of acetylation targets in prokaryotes and indicate a new direction for further research on bacterial DNA repair mechanisms. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Recovery of uranium from 30 vol % tributyl phosphate solvents containing dibutyl phosphate

International Nuclear Information System (INIS)

Mailen, J.C.; Tallent, O.K.

1986-01-01

A number of solid sorbents were tested for the removal of uranium and dibutyl phosphate (DBP) from 30% tributyl phosphate (TBP) solvent. The desired clean uranium product can be obtained either by removing the DBP, leaving the uranium in the solvent for subsequent stripping, or by removing the uranium, leaving the DBP in the solvent for subsequent treatment. The tests performed show that it is relatively easy to preferentially remove uranium from solvents containing uranium and DBP, but quite difficult to remove DBP preferentially. The current methods could be used by removing the uranium (as by a cation exchange resin) and then using either an anion exchange resin in the hydroxyl form or a conventional treatment with a basic solution to remove the DBP. Treatment of a solvent with a cation exchange resin could be useful for recovery of valuable metals from solvents containing DBP and might be used to remove cations before scrubbing a solvent with a basic solution to minimize emulsion formation. 6 refs., 9 figs

Comparative analysis of pharmacological treatments with N-acetyl-DL-leucine (Tanganil) and its two isomers (N-acetyl-L-leucine and N-acetyl-D-leucine) on vestibular compensation: Behavioral investigation in the cat.

Science.gov (United States)

Tighilet, Brahim; Leonard, Jacques; Bernard-Demanze, Laurence; Lacour, Michel

2015-12-15

Head roll tilt, postural imbalance and spontaneous nystagmus are the main static vestibular deficits observed after an acute unilateral vestibular loss (UVL). In the UVL cat model, these deficits are fully compensated over 6 weeks as the result of central vestibular compensation. N-Acetyl-dl-leucine is a drug prescribed in clinical practice for the symptomatic treatment of acute UVL patients. The present study investigated the effects of N-acetyl-dl-leucine on the behavioral recovery after unilateral vestibular neurectomy (UVN) in the cat, and compared the effects of each of its two isomers N-acetyl-L-leucine and N-acetyl-D-leucine. Efficacy of these three drug treatments has been evaluated with respect to a placebo group (UVN+saline water) on the global sensorimotor activity (observation grids), the posture control (support surface measurement), the locomotor balance (maximum performance at the rotating beam test), and the spontaneous vestibular nystagmus (recorded in the light). Whatever the parameters tested, the behavioral recovery was strongly and significantly accelerated under pharmacological treatments with N-acetyl-dl-leucine and N-acetyl-L-leucine. In contrast, the N-acetyl-D-leucine isomer had no effect at all on the behavioral recovery, and animals of this group showed the same recovery profile as those receiving a placebo. It is concluded that the N-acetyl-L-leucine isomer is the active part of the racemate component since it induces a significant acceleration of the vestibular compensation process similar (and even better) to that observed under treatment with the racemate component only. Copyright © 2015 Elsevier B.V. All rights reserved.

Histone Acetylation in Fungal Pathogens of Plants

Directory of Open Access Journals (Sweden)

Junhyun Jeon

2014-03-01

Full Text Available Acetylation of histone lysine residues occurs in different organisms ranging from yeast to plants and mammals for the regulation of diverse cellular processes. With the identification of enzymes that create or reverse this modification, our understanding on histone acetylation has expanded at an amazing pace during the last two decades. In fungal pathogens of plants, however, the importance of such modification has only just begun to be appreciated in the recent years and there is a dearth of information on how histone acetylation is implicated in fungal pathogenesis. This review covers the current status of research related to histone acetylation in plant pathogenic fungi and considers relevant findings in the interaction between fungal pathogens and host plants. We first describe the families of histone acetyltransferases and deacetylases. Then we provide the cases where histone acetylation was investigated in the context of fungal pathogenesis. Finally, future directions and perspectives in epigenetics of fungal pathogenesis are discussed.

Expression of mung bean pectin acetyl esterase in potato tubers: effect on acetylation of cell wall polymers and tuber mechanical properties.

Science.gov (United States)

Orfila, Caroline; Dal Degan, Florence; Jørgensen, Bodil; Scheller, Henrik Vibe; Ray, Peter M; Ulvskov, Peter

2012-07-01

A mung bean (Vigna radiata) pectin acetyl esterase (CAA67728) was heterologously expressed in tubers of potato (Solanum tuberosum) under the control of the granule-bound starch synthase promoter or the patatin promoter in order to probe the significance of O-acetylation on cell wall and tissue properties. The recombinant tubers showed no apparent macroscopic phenotype. The enzyme was recovered from transgenic tubers using a high ionic strength buffer and the extract was active against a range of pectic substrates. Partial in vivo de-acetylation of cell wall polysaccharides occurred in the transformants, as shown by a 39% decrease in the degree of acetylation (DA) of tuber cell wall material (CWM). Treatment of CWM using a combination of endo-polygalacturonase and pectin methyl esterase extracted more pectin polymers from the transformed tissue compared to wild type. The largest effect of the pectin acetyl esterase (68% decrease in DA) was seen in the residue from this extraction, suggesting that the enzyme is preferentially active on acetylated pectin that is tightly bound to the cell wall. The effects of acetylation on tuber mechanical properties were investigated by tests of failure under compression and by determination of viscoelastic relaxation spectra. These tests suggested that de-acetylation resulted in a stiffer tuber tissue and a stronger cell wall matrix, as a result of changes to a rapidly relaxing viscoelastic component. These results are discussed in relation to the role of pectin acetylation in primary cell walls and its implications for industrial uses of potato fibres.

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

African Journals Online (AJOL)

Effectiveness of ranitidine bismuth citrate and proton pump inhibitor based triple therapies of Helicobacter pylori in Turkey. ... Results: When we look at the eradication rates of the treatment groups, only two groups (ranitidine bismuth citrate and rabeprazole groups) had eradication rates greater than 80%, both at intention to ...

Citrate increases glass transition temperature of vitrified sucrose preparations

NARCIS (Netherlands)

Kets, E.P.W.; Lipelaar, P.J.; Hoekstra, F.A.; Vromans, H.

2004-01-01

The aim of this study was to investigate the effect of sodium citrate on the properties of dried amorphous sucrose glasses. Addition of sodium citrate to a sucrose solution followed by freeze-drying or convective drying resulted in a glass transition temperature (T-g) that was higher than the

Phosphonates as alternative to tributyl phosphate for the separation of actinides from fission products

International Nuclear Information System (INIS)

Vyas, Chirag K.; Joshirao, Pranav M.; Manchanda, Vijay K.; Rao, C.V.S. Brahmmananda; Jayalakshmi, S.

2015-01-01

The present work investigates the role of increase in the basicity of organophosphorus extractant (dialkylalkyl phosphonates) on the uptake of actinides and fission products vis-a-vis tributyl phosphate (TBP), currently employed as a universal extractant. Two dialkylalkyl phosphonates viz. dibutylpropyl phosphonate (DBPrP) and dibutylpentyl phosphonate (DBPeP) were synthesized, characterized and evaluated for their solvent extraction behavior towards U(VI), Th(IV), Eu(III) and Tc(VII) in nitric acid medium ranging from 0.01-6 M. It was observed that increasing the basicity of the phosphoryl oxygen enhanced the uptake of the actinides and the distribution coefficient values were significantly larger as compared to TBP. The limiting organic concentration (LOC) value was estimated for Th(IV) for these extractants and compared with the TBP system. The separation factors of actinides with phosphonates over Tc(VII) are distinctly better than that with TBP.

Study of the physico-chemical agents influencing uranium and plutonium extraction by tributylphosphate in nitric media; Etude des facteurs physico-chimiques intervenant dans l'extraction de l'uranium et du plutonium par le phosphate de tributyle en milieu nitrique

Energy Technology Data Exchange (ETDEWEB)

Tarnero, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-03-01

The following different factors are reviewed: tributylphosphate concentration, nitric acid concentration, influence of non-extractable nitrates, simultaneous presence of uranium and plutonium, presence of some different ions, temperature, nature of the diluent, addition of a second active solvent (synergic or antagonistic effect), tributylphosphate and diluent degradation. (author) [French] On passe en revue les differents facteurs suivants: concentration en phosphate de tributyle, concentration en acide nitrique, influence des nitrates non-extractibles, presence simultanee d'uranium et de plutonium, presence d'ions divers, addition d'un second solvant actif (effet de synergie, ou effet antagoniste), degradation du phosphate de tributyle et des solvants inertes. (auteur)

Determination of 21 trace impurities in UO2 with tributyl phosphate chromatographic separation-USN-inductively coupled/atomic emission spectrometric

International Nuclear Information System (INIS)

Hou Lieqi; Wang Shuan; Li Jie

1996-03-01

A method of tributyl phosphate chromatographic separation-USN-inductively coupled/atomic emission spectrometric was selected. And the parameters, interference of acid concentrations, interference of coexisting elements, selecting of flow for carrier gas, solution temperature were studied. When the sampling amount is 250 mg, the determination range for Al, Ag, Ba, Ca, Cd, Co, Cr, Cu, Fe, In, Li, Mg, Mn, Mo, Ni, Pb, Sn, Ti, V, Y and Zn are 0.2∼100 ng· -1 , recovery are 94%∼110%. The RSD (n 8) are 0.8%∼6.2%. (3 refs., 4 tabs.)

The Acetyl Group Buffering Action of Carnitine Acetyltransferase Offsets Macronutrient-Induced Lysine Acetylation of Mitochondrial Proteins

Directory of Open Access Journals (Sweden)

Michael N. Davies

2016-01-01

Full Text Available Lysine acetylation (AcK, a posttranslational modification wherein a two-carbon acetyl group binds covalently to a lysine residue, occurs prominently on mitochondrial proteins and has been linked to metabolic dysfunction. An emergent theory suggests mitochondrial AcK occurs via mass action rather than targeted catalysis. To test this hypothesis, we performed mass spectrometry-based acetylproteomic analyses of quadriceps muscles from mice with skeletal muscle-specific deficiency of carnitine acetyltransferase (CrAT, an enzyme that buffers the mitochondrial acetyl-CoA pool by converting short-chain acyl-CoAs to their membrane permeant acylcarnitine counterparts. CrAT deficiency increased tissue acetyl-CoA levels and susceptibility to diet-induced AcK of broad-ranging mitochondrial proteins, coincident with diminished whole body glucose control. Sub-compartment acetylproteome analyses of muscles from obese mice and humans showed remarkable overrepresentation of mitochondrial matrix proteins. These findings reveal roles for CrAT and L-carnitine in modulating the muscle acetylproteome and provide strong experimental evidence favoring the nonenzymatic carbon pressure model of mitochondrial AcK.

Adhesives for Achieving Durable Bonds with Acetylated Wood

Science.gov (United States)

Charles Frihart; Rishawn Brandon; James Beecher; Rebecca Ibach

2017-01-01

Acetylation of wood imparts moisture durability, decay resistance, and dimensional stability to wood; however, making durable adhesive bonds with acetylated wood can be more difficult than with unmodified wood. The usual explanation is that the acetylated surface has fewer hydroxyl groups, resulting in a harder-to-wet surface and in fewer hydrogen bonds between wood...

Synthesis and characterization of nanoparticles ferrites of the type ZN_xCu_1_-_xFE_2O_4 and your application catalyst in acetylation vegetable oils

International Nuclear Information System (INIS)

Casagrande, D.S; Costa, W.V; Hechenleitner, A.A.W.; Oliveira, D.M.F. de; Pineda, E.A.G.

2016-01-01

In this work were synthesized copper and zinc ferrites (0 - 10% mol with respect to copper), by the combustion method, using citrate as stabilizer. The obtained products were analyzed by Infrared spectrometry (FTIR), Raman spectroscopy (RAMAN) and x-ray diffractometry (DRX). Synthesized ferrites present hematite phase, maghemite phase and copper ferrite phases. The analysis indicated that increasing the zinc content leads to decreased of hematite phase. Increasing of zinc content lead to an increase of particle size. The best results of oil acylation were obtained with ferrites containing 2 and 4% of zinc, wherein the increase the increase of yield of acetylated product reached at 19% when compared with the yield obtained whit copper ferrite without zinc. (author)

Studies investigating the excretion of acetyl urea in the milk of dairy cows receiving oral doses of /sup 14/C acetyl urea

Energy Technology Data Exchange (ETDEWEB)

Bergner, H; Kijora, C; Goersch, R [Humboldt-Universitaet, Berlin (German Democratic Republic). Sektion Tierproduktion und Veterinaermedizin

1976-01-01

2 experimental cows were fed acetyl urea several weeks before the trial was started. The first cow received a daily amount of 200 g and the second cow 855 g. On the first day of experiment both cows were given 5 mCi of /sup 14/C acetyl urea intraruminally. Up to 6 hrs after the beginning of the experiment acetyl urea in blood plasma was shown to contain a higher proportion of /sup 14/C activity than urea. 0.21 g urea and 0.18 g acetyl urea were contained in 1 kg of milk from cow No 1 while 1 kg of milk from cow No 2 contained 0.18 g urea and 0.12 g acetyl urea. The feeding of acetyl urea to dairy cows is not recommended on the basis of the fact that any further contamination of human nutrition with foreign substances should be possibly avoided.

Diffuse abdominal gallium-67 citrate uptake in salmonella infections

International Nuclear Information System (INIS)

Garty, I.; Koren, A.

1987-01-01

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

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

Science.gov (United States)

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

Scintiscanning of lung cancer with 67Ga-citrate

International Nuclear Information System (INIS)

Abe, Mitsunobu; Ohyama, Shiro; Ohtsuka, Hassau; Hoshina, Toshifumi; Takanashi, Shuko

1982-01-01

The clinical value of scintigram with 67 Ga-citrate in 58 patients with primary lung cancer was investigated and discussed. The results are as follows: 1) Positive 67 Ga-scintigram was obtained in 83% of patients with primary lung cancer. The histologically confirmed positive ratios were 74% in adenocarcinoma, 94% in squamous cell carcinoma, 80% in small cell carcinoma and 100% in large cell carcinoma. 2) The positive ratios according to T category of TNM classification was 0% (0/1) in T1, 83% (20/24) in T2 and 85% (28/33) in T3. 3) According to rules for classification of lung cancer (TNM UICC 1978,) T2 cases were divided into two groups. a) In patients with hilar involvements on chest X-ray, positive accumulation to the hilar region was 88% (7/8). b) In patients without the evidence of hilar involvements on chest X-ray, the positive accumulation to the hilar region was 81% (13/16). 4) All cases extending to the mediastinum showed abnormal 67 Ga-citrate accumulation regardless of histological type. 67 Ga-citrate scanning is useful in evaluating the extent of lung cancer, especially with hilar and mediastinal involvements. Therefore 67 Ga-citrate scanning seems to be very useful for planning the radiotherapy for lung cancer. (author)

Acetylation Increases EWS-FLI1 DNA Binding and Transcriptional Activity

International Nuclear Information System (INIS)

Schlottmann, Silke; Erkizan, Hayriye V.; Barber-Rotenberg, Julie S.; Knights, Chad; Cheema, Amrita; Üren, Aykut; Avantaggiati, Maria L.; Toretsky, Jeffrey A.

2012-01-01

Ewing Sarcoma (ES) is associated with a balanced chromosomal translocation that in most cases leads to the expression of the oncogenic fusion protein and transcription factor EWS-FLI1. EWS-FLI1 has been shown to be crucial for ES cell survival and tumor growth. However, its regulation is still enigmatic. To date, no functionally significant post-translational modifications of EWS-FLI1 have been shown. Since ES are sensitive to histone deacetylase inhibitors (HDI), and these inhibitors are advancing in clinical trials, we sought to identify if EWS-FLI1 is directly acetylated. We convincingly show acetylation of the C-terminal FLI1 (FLI1-CTD) domain, which is the DNA binding domain of EWS-FLI1. In vitro acetylation studies showed that acetylated FLI1-CTD has higher DNA binding activity than the non-acetylated protein. Over-expression of PCAF or treatment with HDI increased the transcriptional activity of EWS-FLI1, when co-expressed in Cos7 cells. However, our data that evaluates the acetylation of full-length EWS-FLI1 in ES cells remains unclear, despite creating acetylation specific antibodies to four potential acetylation sites. We conclude that EWS-FLI1 may either gain access to chromatin as a result of histone acetylation or undergo regulation by direct acetylation. These data should be considered when patients are treated with HDAC inhibitors. Further investigation of this phenomenon will reveal if this potential acetylation has an impact on tumor response.

Cell differentiation during sexual development of the fungus Sordaria macrospora requires ATP citrate lyase activity.

Science.gov (United States)

Nowrousian, M; Masloff, S; Pöggeler, S; Kück, U

1999-01-01

During sexual development, mycelial cells from most filamentous fungi differentiate into typical fruiting bodies. Here, we describe the isolation and characterization of the Sordaria macrospora developmental mutant per5, which exhibits a sterile phenotype with defects in fruiting body maturation. Cytological investigations revealed that the mutant strain forms only ascus precursors without any mature spores. Using an indexed cosmid library, we were able to complement the mutant to fertility by DNA-mediated transformation. A single cosmid clone, carrying a 3.5-kb region able to complement the mutant phenotype, has been identified. Sequencing of the 3.5-kb region revealed an open reading frame of 2.1 kb interrupted by a 66-bp intron. The predicted polypeptide (674 amino acids) shows significant homology to eukaryotic ATP citrate lyases (ACLs), with 62 to 65% amino acid identity, and the gene was named acl1. The molecular mass of the S. macrospora ACL1 polypeptide is 73 kDa, as was verified by Western blot analysis with a hemagglutinin (HA) epitope-tagged ACL1 polypeptide. Immunological in situ detection of the HA-tagged polypeptide demonstrated that ACL is located within the cytosol. Sequencing of the mutant acl1 gene revealed a 1-nucleotide transition within the coding region, resulting in an amino acid substitution within the predicted polypeptide. Further evidence that ACL1 is essential for fruiting body maturation comes from experiments in which truncated and mutated versions of the acl1 gene were used for transformation. None of these copies was able to reconstitute the fertile phenotype in transformed per5 recipient strains. ACLs are usually involved in the formation of cytosolic acetyl coenzyme A (acetyl-CoA), which is used for the biosynthesis of fatty acids and sterols. Protein extracts from the mutant strain showed a drastic reduction in enzymatic activity compared to values obtained from the wild-type strain. Investigation of the time course of ACL

Directing vanillin production from ferulic acid by increased acetyl-CoA consumption in recombinant Escherichia coli.

Science.gov (United States)

Lee, Eun-Gyeong; Yoon, Sang-Hwal; Das, Amitabha; Lee, Sook-Hee; Li, Cui; Kim, Jae-Yean; Choi, Myung-Suk; Oh, Deok-Kun; Kim, Seon-Won

2009-01-01

The amplification of gltA gene encoding citrate synthase of TCA cycle was required for the efficient conversion of acetyl-CoA, generated during vanillin production from ferulic acid, to CoA, which is essential for vanillin production. Vanillin of 1.98 g/L was produced from the E. coli DH5alpha (pTAHEF-gltA) with gltA amplification in 48 h of culture at 3.0 g/L of ferulic acid, which was about twofold higher than the vanillin production of 0.91 g/L obtained by the E. coli DH5alpha (pTAHEF) without gltA amplification. The icdA gene encoding isocitrate dehydrogenase of TCA cycle was deleted to make the vanillin producing E. coli utilize glyoxylate bypass which enables more efficient conversion of acetyl-CoA to CoA in comparison with TCA cycle. The production of vanillin by the icdA null mutant of E. coli BW25113 harboring pTAHEF was enhanced by 2.6 times. The gltA amplification of the glyoxylate bypass in the icdA null mutant remarkably increased the production rate of vanillin with a little increase in the amount of vanillin production. The real synergistic effect of gltA amplification and icdA deletion was observed with use of XAD-2 resin reducing the toxicity of vanillin produced during culture. Vanillin of 5.14 g/L was produced in 24 h of the culture with molar conversion yield of 86.6%, which is the highest so far in vanillin production from ferulic acid using recombinant E. coli.

Sildenafil citrate (Viagra) enhances vasodilatation by atrial natriuretic peptide in normal dogs.

Science.gov (United States)

Ishikura, Fuminobu; Beppu, Shintaro; Asanuma, Toshihiko; Seward, James B; Khandheria, Bijoy K

2007-12-01

Sildenafil citrate (Viagra) is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5, which might enhance the vasorelaxant and natriuretic actions of atrial natriuretic peptide (ANP) in patients with heart failure. The objective of this study was to examine the combined effect of Viagra on hemodynamic changes during infusion of exogenous ANP. Healthy male beagles were used to assess systemic blood pressure, pulmonary artery pressure (PAP), and plasma levels of cGMP. After hemodynamic variables were measured, 0.1 microg.kg(-1).min(-1) of ANP was given during this study. One hour after initiating infusion of ANP, 2 mg/kg of sildenafil citrate or vehicle was given orally via a nasogastric tube. Hemodynamic changes were measured before and 1 h after these administrations. Mean systemic and PAP decreased during infusion of ANP, and further decreased after sildenafil citrate administration, however, mean systemic blood pressure decreased within 10 mmHg. Plasma levels of cGMP also increased after sildenafil citrate administration. In normal dogs, sildenafil citrate enhances the vasodilator effect of ANP by increasing the cGMP level, however, the concomitant use of sildenafil citrate with ANP will not induce severe hypotension.

Autoimmune regulator is acetylated by transcription coactivator CBP/p300

Energy Technology Data Exchange (ETDEWEB)

Saare, Mario, E-mail: mario.saare@ut.ee [Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu (Estonia); Rebane, Ana [Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu (Estonia); SIAF, Swiss Institute of Allergy and Asthma Research, University of Zuerich, Davos (Switzerland); Rajashekar, Balaji; Vilo, Jaak [BIIT, Bioinformatics, Algorithmics and Data Mining group, Institute of Computer Science, University of Tartu, Tartu (Estonia); Peterson, Paert [Molecular Pathology, Institute of General and Molecular Pathology, University of Tartu, 19th Ravila Str, Tartu (Estonia)

2012-08-15

The Autoimmune Regulator (AIRE) is a regulator of transcription in the thymic medulla, where it controls the expression of a large set of peripheral-tissue specific genes. AIRE interacts with the transcriptional coactivator and acetyltransferase CBP and synergistically cooperates with it in transcriptional activation. Here, we aimed to study a possible role of AIRE acetylation in the modulation of its activity. We found that AIRE is acetylated in tissue culture cells and this acetylation is enhanced by overexpression of CBP and the CBP paralog p300. The acetylated lysines were located within nuclear localization signal and SAND domain. AIRE with mutations that mimicked acetylated K243 and K253 in the SAND domain had reduced transactivation activity and accumulated into fewer and larger nuclear bodies, whereas mutations that mimicked the unacetylated lysines were functionally similar to wild-type AIRE. Analogously to CBP, p300 localized to AIRE-containing nuclear bodies, however, the overexpression of p300 did not enhance the transcriptional activation of AIRE-regulated genes. Further studies showed that overexpression of p300 stabilized the AIRE protein. Interestingly, gene expression profiling revealed that AIRE, with mutations mimicking K243/K253 acetylation in SAND, was able to activate gene expression, although the affected genes were different and the activation level was lower from those regulated by wild-type AIRE. Our results suggest that the AIRE acetylation can influence the selection of AIRE activated genes. -- Highlights: Black-Right-Pointing-Pointer AIRE is acetylated by the acetyltransferases p300 and CBP. Black-Right-Pointing-Pointer Acetylation occurs between CARD and SAND domains and within the SAND domain. Black-Right-Pointing-Pointer Acetylation increases the size of AIRE nuclear dots. Black-Right-Pointing-Pointer Acetylation increases AIRE protein stability. Black-Right-Pointing-Pointer AIRE acetylation mimic regulates a different set of AIRE

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

Science.gov (United States)

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.

Cyclic AMP Inhibits the Activity and Promotes the Acetylation of Acetyl-CoA Synthetase through Competitive Binding to the ATP/AMP Pocket.

Science.gov (United States)

Han, Xiaobiao; Shen, Liqiang; Wang, Qijun; Cen, Xufeng; Wang, Jin; Wu, Meng; Li, Peng; Zhao, Wei; Zhang, Yu; Zhao, Guoping

2017-01-27

The high-affinity biosynthetic pathway for converting acetate to acetyl-coenzyme A (acetyl-CoA) is catalyzed by the central metabolic enzyme acetyl-coenzyme A synthetase (Acs), which is finely regulated both at the transcriptional level via cyclic AMP (cAMP)-driven trans-activation and at the post-translational level via acetylation inhibition. In this study, we discovered that cAMP directly binds to Salmonella enterica Acs (SeAcs) and inhibits its activity in a substrate-competitive manner. In addition, cAMP binding increases SeAcs acetylation by simultaneously promoting Pat-dependent acetylation and inhibiting CobB-dependent deacetylation, resulting in enhanced SeAcs inhibition. A crystal structure study and site-directed mutagenesis analyses confirmed that cAMP binds to the ATP/AMP pocket of SeAcs, and restrains SeAcs in an open conformation. The cAMP contact residues are well conserved from prokaryotes to eukaryotes, suggesting a general regulatory mechanism of cAMP on Acs. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Methods of Uranium Determination in solutions of Tributyl Phosphate and Kerosene; Metodos de determinacion de uranio en soluciones de fosfato de tributilo y queroseno

Energy Technology Data Exchange (ETDEWEB)

Petrement Eguiluz, J; Palomares Delgado, F

1962-07-01

A new analytical method for the determination of uranium in organic solutions of tributyl phosphate and kerosene is proposed. In this method the uranium is reectracted from the aqueous phase by reduction with cadmium in acid solution. The uranium can be determined in this solution by the usual methods. In case of very diluted solutions, a direct spectrophtometrical determination of uranium in the organic phase with dibenzoylmethane is proposed. (Author) 21 refs.

Affinity for a malignant tumor and organs of sup(99m)Tc-citrate complex

Energy Technology Data Exchange (ETDEWEB)

Ando, A; Sanada, S; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Hisada, K; Nakazawa, N

1976-12-01

In order to investigate the tumor affinity of sup(99m)Tc-citrate complex, it was synthesized in three different ways. By (1) reducing sup(99m)TcO/sub 4//sup -/ with FeCl/sub 3//sup -/ ascorbic acid in 0.15 M sodium citrate, (2) reducing sup(99m)TcO/sub 4//sup -/ with SnCl/sub 2/ solution in 0.15 M sodium citrate, and (3) reducing sup(99m)TcO/sub 4//sup -/ with NaBH/sub 4/ in 0.45 sodium citrate. It was presumed from thinlayer chromatography that the sup(99m)Tc-citrate complexes synthesized in three ways were chemically different. These sup(99m)Tc-citrate complexes were injected intravenously into the rats subcutaneously transplanted with Yoshida sarcoma. These rats were sacrificed at one hour and three hours after injection. The radioactivity of the tumor, blood, muscle, liver, kidney, spleen and urine was measured by well-type scintillation counter. The retention values in these organs and the excretion rates in the urine were calculated. sup(99m)Tc-citrate complex synthesized by reducing sup(99m)TcO/sub 4//sup -/ with SnCl/sub 2/ solution had very strong affinity for the malignant tumor but the other two sup(99m)Tc-citrate complexes had no affinity to the malignant tumor. Excretion rates (% dose) of sup(99m)Tc-citrate complexes in one hour were from 65% to 75%.

The growing landscape of lysine acetylation links metabolism and cell signalling

DEFF Research Database (Denmark)

Choudhary, Chuna Ram; Weinert, Brian Tate; Nishida, Yuya

2014-01-01

Lysine acetylation is a conserved protein post-translational modification that links acetyl-coenzyme A metabolism and cellular signalling. Recent advances in the identification and quantification of lysine acetylation by mass spectrometry have increased our understanding of lysine acetylation...

Investigation of acetyl migrations in furanosides

Directory of Open Access Journals (Sweden)

Migaud ME

2006-07-01

Full Text Available Abstract Standard reaction conditions for the desilylation of acetylated furanoside (riboside, arabinoside and xyloside derivatives facilitate acyl migration. Conditions which favour intramolecular and intermolecular mechanisms have been identified with intermolecular transesterifications taking place under mild basic conditions when intramolecular orthoester formations are disfavoured. In acetyl ribosides, acyl migration could be prevented when desilylation was catalysed by cerium ammonium nitrate.

Clomiphene citrate therapy for male infertility.

Science.gov (United States)

Allag, I S; Alexander, N J

1979-11-01

We have summarized 697 reported cases of the use of clomiphene citrate for the improvement of semen quality. Basal levels of gonadotropins are useful criteria for the differential diagnosis of hypo- and hypergonadotropic hypogonadism. Patients with an intact hypothalamic-pituitary-gonadal axis are most likely to respond to clomiphene citrate. Twenty-five mg. per day, administered in a cyclic fashion for a period of six to nine months, caused the greatest improvement. A higher dose (50 mg. per day) may be effective in men who do not respond to 25 mg. During the course of therapy gonadotropin levels and semen samples should be analyzed periodically. This drug is not currently approved for use in men; the incidence of side effects, particularly with long-term treatment, is unknown.

Synthesis of polyrotaxanes from acetyl-β-cyclodextrin

Science.gov (United States)

Ristić, I. S.; Nikolić, L.; Nikolić, V.; Ilić, D.; Budinski-Simendić, J.

2011-12-01

Polyrotaxanes are intermediary products in the synthesis of topological gels. They are created by inclusion complex formation of hydrophobic linear macromolecules with cyclodextrins or their derivatives. Then, pairs of cyclodextrin molecules with covalently linkage were practically forming the nodes of the semi-flexible polymer network. Such gels are called topological gels and they can absorb huge quantities of water due to the net flexibility allowing the poly(ethylene oxide) chains to slide through the cyclodextrin cavities, without being pulled out altogether. For polyrotaxane formation poly(ethylene oxide) was used like linear macromolecules. There are hydroxyl groups at poly(ethylene oxide) chains, whereby the linking of the voluminous molecules should be made. To avoid the reaction of cyclodextrin OH groups with stoppers, they should be protected by, e.g., acetylation. In this work, the acetylation of the OH groups of β-cyclodextrin was performed by acetic acid anhydride with iodine as the catalyst. The acetylation reaction was assessed by the FTIR and HPLC method. By the HPLC analysis was found that the acetylation was completed in 20 minutes. Inserting of poly(ethylene oxide) with 4000 g/mol molecule mass into acetyl-β-cyclodextrin with 2:1 poly(ethylene oxide) monomer unit to acetyl-β-cyclodextrin ratio was also monitored by FTIR, and it was found that the process was completed in 12 h at the temperature of 10°C. If the process is performed at temperatures above 10°C, or for periods longer than 12 hours, the process of uncontrolled hydrolysis of acetate groups was initiated.

Structure, morphology and functionality of acetylated and oxidised barley starches.

Science.gov (United States)

El Halal, Shanise Lisie Mello; Colussi, Rosana; Pinto, Vânia Zanella; Bartz, Josiane; Radunz, Marjana; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2015-02-01

Acetylation and oxidation are chemical modifications which alter the properties of starch. The degree of modification of acetylated and oxidized starches is dependent on the catalyst and active chlorine concentrations, respectively. The objective of this study was to evaluate the effect of acetylation and oxidation on the structural, morphological, physical-chemical, thermal and pasting properties of barley starch. Barley starches were acetylated at different catalyst levels (11%, 17%, and 23% of NaOH solution) and oxidized at different sodium hypochlorite concentrations (1.0%, 1.5%, and 2.0% of active chlorine). Fourier-transformed infrared spectroscopy (FTIR), X-ray diffractograms, thermal, morphological, and pasting properties, swelling power and solubility of starches were evaluated. The degree of substitution (DS) of the acetylated starches increased with the rise in catalyst concentration. The percentage of carbonyl (CO) and carboxyl (COOH) groups in oxidized starches also increased with the rise of active chlorine level. The presence of hydrophobic acetyl groups, carbonyl and carboxyl groups caused a partial disorganization and depolymerization of starch granules. The structural, morphological and functional changes in acetylated and oxidized starches varied according to reaction conditions. Acetylation makes barley starch more hydrophobic by the insertion of acetyl groups. Also the oxidation promotes low retrogradation and viscosity. All these characteristics are important for biodegradable film production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Lysine Acetylation of CREBH Regulates Fasting-Induced Hepatic Lipid Metabolism

Science.gov (United States)

Kim, Hyunbae; Mendez, Roberto; Chen, Xuequn; Fang, Deyu

2015-01-01

Cyclic AMP-responsive element-binding protein 3-like 3, hepatocyte specific (CREBH), is a hepatic transcription factor that functions as a key regulator of energy homeostasis. Here, we defined a regulatory CREBH posttranslational modification process, namely, lysine-specific acetylation, and its functional involvement in fasting-induced hepatic lipid metabolism. Fasting induces CREBH acetylation in mouse livers in a time-dependent manner, and this event is critical for CREBH transcriptional activity in regulating hepatic lipid homeostasis. The histone acetyltransferase PCAF-mediated acetylation and the deacetylase sirtuin-1-mediated deacetylation coexist to maintain CREBH acetylation states under fasting conditions. Site-directed mutagenesis and functional analyses revealed that the lysine (K) residue at position 294 (K294) within the bZIP domain of the CREBH protein is the site where fasting-induced acetylation/deacetylation occurs. Introduction of the acetylation-deficient (K294R) or acetylation-mimicking (K294Q) mutation inhibited or enhanced CREBH transcriptional activity, respectively. Importantly, CREBH acetylation at lysine 294 was required for the interaction and synergy between CREBH and peroxisome proliferator-activated receptor α (PPARα) in activating their target genes upon fasting or glucagon stimulation. Introduction of the CREBH lysine 294 mutation in the liver leads to hepatic steatosis and hyperlipidemia in animals under prolonged fasting. In summary, our study reveals a molecular mechanism by which fasting or glucagon stimulation modulates lipid homeostasis through acetylation of CREBH. PMID:26438600

Study of the tributyl phosphate - 30% dodecane solvent; Etude du solvant phosphate tributylique - 30 % dodecane

Energy Technology Data Exchange (ETDEWEB)

Leroy, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses. Centre d' Etudes Nucleaires, 92 (France)

1967-07-01

This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [French] Cette etude, d'origine bibliographique, regroupe les caracteristiques physico-chimiques essentielles du phosphate tributylique (TBP) dilue a 30% en volume dans du dodecane. Ce melange constitue un agent d'extraction tres utilise dans le traitement des combustibles nucleaires. Les principaux points traites sont les suivants: -) les constituants (TBP et diluants), -) les systemes TBP-diluants non charges, -) les systemes TBP-diluants-eau, -) les systemes TBP-diluants-eau-acide nitrique, et -) les solvants industriels. (auteur)

nanoparticles synthesized by citrate precursor m

African Journals Online (AJOL)

user

(M=Co, Cu) nanoparticles synthesized by citrate precursor method ... The structural characterization was carried out using an X-ray Diffractometer (Rikagu Miniflex, Japan) ..... His current area of interest includes magnetic nanomaterials.

The biology of lysine acetylation integrates transcriptional programming and metabolism

Directory of Open Access Journals (Sweden)

Mujtaba Shiraz

2011-03-01

Full Text Available Abstract The biochemical landscape of lysine acetylation has expanded from a small number of proteins in the nucleus to a multitude of proteins in the cytoplasm. Since the first report confirming acetylation of the tumor suppressor protein p53 by a lysine acetyltransferase (KAT, there has been a surge in the identification of new, non-histone targets of KATs. Added to the known substrates of KATs are metabolic enzymes, cytoskeletal proteins, molecular chaperones, ribosomal proteins and nuclear import factors. Emerging studies demonstrate that no fewer than 2000 proteins in any particular cell type may undergo lysine acetylation. As described in this review, our analyses of cellular acetylated proteins using DAVID 6.7 bioinformatics resources have facilitated organization of acetylated proteins into functional clusters integral to cell signaling, the stress response, proteolysis, apoptosis, metabolism, and neuronal development. In addition, these clusters also depict association of acetylated proteins with human diseases. These findings not only support lysine acetylation as a widespread cellular phenomenon, but also impel questions to clarify the underlying molecular and cellular mechanisms governing target selectivity by KATs. Present challenges are to understand the molecular basis for the overlapping roles of KAT-containing co-activators, to differentiate between global versus dynamic acetylation marks, and to elucidate the physiological roles of acetylated proteins in biochemical pathways. In addition to discussing the cellular 'acetylome', a focus of this work is to present the widespread and dynamic nature of lysine acetylation and highlight the nexus that exists between epigenetic-directed transcriptional regulation and metabolism.

Effect of sildenafil citrate (Viagra) on coronary flow in normal subjects.

Science.gov (United States)

Ishikura, Fuminobu; Beppu, Shintaro; Ueda, Hiroaki; Nehra, Ajay; Khandheria, Bijoy K

2008-01-01

The purpose of this study was to evaluate the effect of sildenafil citrate (Viagra) on coronary function in normal subjects. The study assessed mean blood pressure, left anterior descending coronary artery (LAD) flow, and echocardiographic variables before and 30 and 60 minutes after taking 50 mg of sildenafil citrate. The mean velocity of LAD flow was assessed with Doppler flow imaging. The study subjects were 6 healthy male volunteers (mean age 37 years). The mean velocity of LAD flow increased 60 minutes after taking sildenafil citrate, but there were no other changes. Two volunteers felt mild flashing and one had mild headache during the study. Sildenafil citrate caused vasodilatation in a normal coronary artery without systemic pressure drops. These results suggest that the agent itself did not have negative effects on the heart in normal subjects.

SERS substrates fabricated using ceramic filters for the detection of bacteria: Eliminating the citrate interference

Science.gov (United States)

Mosier-Boss, P. A.; Sorensen, K. C.; George, R. D.; Sims, P. C.; O'braztsova, A.

2017-06-01

It was found that spectra obtained for bacteria on SERS substrates fabricated by filtering citrate-generated Ag nanoparticles (NPs) onto rigid, ceramic filters exhibited peaks due to citrate as well as the bacteria. In many cases the citrate spectrum overwhelmed that of the bacteria. Given the simplicity of the method to prepare these substrates, means of eliminating this citrate interference were explored. It was found that allowing a mixture of bacteria suspension and citrate-generated Ag NPs to incubate prior to filtering onto the ceramic filter eliminated this interference.

Effects of citrate on hexavalent chromium reduction by structural Fe(II) in nontronite

Energy Technology Data Exchange (ETDEWEB)

Liu, Xiaolei; Dong, Hailiang; Yang, Xuewei; Kovarik, Libor; Chen, Yu; Zeng, Qiang

2018-02-01

Iron-bearing clay minerals and organic matter are two important components in natural environments that influence hexavalent chromium (Cr(VI)) reduction. Previous studies have shown that organic ligands could influence Cr(VI) reduction by aqueous Fe2+ and pyrite. However, the effects of organic ligands on Cr(VI) reduction by structural Fe(II) in clays are not well understood. In this study, the effects of citrate on Cr(VI) reduction by nontronite (NAu-2) were investigated under near neutral pH condition (pH=6). Our results showed that the presence of citrate decreased the rate but increased the amount of Cr(VI) reduction by structural Fe(II) in NAu-2. The decreased reaction rate was likely due to competitive sorption of citrate and polyanionic dichromate (Cr2O7- ), because sorption of dichromate appeared to be the first step for subsequent Cr(VI) reduction. The increased amount of Cr(VI) reduction in the presence of citrate was likely because citrate provided additional reducing power through ligand-metal electron transfer in the presence of soluble Fe 3+ derived from dissolution of reduced NAu-2. Soluble Cr(III)-citrate complex was the possible form of reduced chromium when citrate was present. In contrast, nanometer-sized Cr2O3 particles were the product of Cr(VI) reduction by reduced NAu-2 without citrate. Our study highlights the importance of organic ligands on Cr(VI) reduction and immobilization when iron-bearing clay minerals are applied to treat Cr(VI) contaminant in organic matter rich environments.

Acetyl coenzyme A synthetase is acetylated on multiple lysine residues by a protein acetyltransferase with a single Gcn5-type N-acetyltransferase (GNAT) domain in Saccharopolyspora erythraea.

Science.gov (United States)

You, Di; Yao, Li-Li; Huang, Dan; Escalante-Semerena, Jorge C; Ye, Bang-Ce

2014-09-01

Reversible lysine acetylation (RLA) is used by cells of all domains of life to modulate protein function. To date, bacterial acetylation/deacetylation systems have been studied in a few bacteria (e.g., Salmonella enterica, Bacillus subtilis, Escherichia coli, Erwinia amylovora, Mycobacterium tuberculosis, and Geobacillus kaustophilus), but little is known about RLA in antibiotic-producing actinomycetes. Here, we identify the Gcn5-like protein acetyltransferase AcuA of Saccharopolyspora erythraea (SacAcuA, SACE_5148) as the enzyme responsible for the acetylation of the AMP-forming acetyl coenzyme A synthetase (SacAcsA, SACE_2375). Acetylated SacAcsA was deacetylated by a sirtuin-type NAD(+)-dependent consuming deacetylase (SacSrtN, SACE_3798). In vitro acetylation/deacetylation of SacAcsA enzyme was studied by Western blotting, and acetylation of lysine residues Lys(237), Lys(380), Lys(611), and Lys(628) was confirmed by mass spectrometry. In a strain devoid of SacAcuA, none of the above-mentioned Lys residues of SacAcsA was acetylated. To our knowledge, the ability of SacAcuA to acetylate multiple Lys residues is unique among AcuA-type acetyltransferases. Results from site-specific mutagenesis experiments showed that the activity of SacAcsA was controlled by lysine acetylation. Lastly, immunoprecipitation data showed that in vivo acetylation of SacAcsA was influenced by glucose and acetate availability. These results suggested that reversible acetylation may also be a conserved regulatory posttranslational modification strategy in antibiotic-producing actinomycetes. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Mode of action of Fusarium moniliforme endopolygalacturonase towards acetylated pectin.

NARCIS (Netherlands)

Bonnin, E.; Alebeek, van G.J.W.M.; Voragen, A.G.J.; Thibault, J.F.

2003-01-01

Endopolygalacturonase from Fusarium moniliforme was used to degrade acetylated homogalacturonan previously prepared from sugar beet pulp. The initial velocity and the final percentage of hydrolysis decreased-very rapidly with increasing degree of acetylation, showing that acetyl substitution

Whole-body retention studies of /sup 169/Yb-citrate. Estimation of radiation dose to humans from /sup 169/Yb-citrate

Energy Technology Data Exchange (ETDEWEB)

Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Mori, H; Ando, I; Hisada, K

1977-09-01

For purpose of the estimation of the radiation dose to humans from /sup 169/Yb-citrate, the whole-body retention studies using five rats were carried out. Following intravenous administration of /sup 169/Yb-citrate, the whole-body activity was monitored for 40 days by the animal counter. The whole-body retention curve consisted of three components: the first with a 3.6 hours effective half-time, the second with an 154 hours effective half-time and the third with a 29.9 days effective half-time. Therefore it was assumed that 32% of the administered /sup 169/Yb-citrate clears from the kidney with a short biologic half-time (3.6 hours), 18% remains in the liver and other soft tissues with a relatively long biologic half-time (194 hours) and 50% remains in the bone with a long biologic half-time (850 days). Based on these biological data and the MIRD Committee method, the average dose to the bone and whole-body were 20.8 rads/mCi and 4.5 rads/mCi respectively.

CPLA 1.0: an integrated database of protein lysine acetylation.

Science.gov (United States)

Liu, Zexian; Cao, Jun; Gao, Xinjiao; Zhou, Yanhong; Wen, Longping; Yang, Xiangjiao; Yao, Xuebiao; Ren, Jian; Xue, Yu

2011-01-01

As a reversible post-translational modification (PTM) discovered decades ago, protein lysine acetylation was known for its regulation of transcription through the modification of histones. Recent studies discovered that lysine acetylation targets broad substrates and especially plays an essential role in cellular metabolic regulation. Although acetylation is comparable with other major PTMs such as phosphorylation, an integrated resource still remains to be developed. In this work, we presented the compendium of protein lysine acetylation (CPLA) database for lysine acetylated substrates with their sites. From the scientific literature, we manually collected 7151 experimentally identified acetylation sites in 3311 targets. We statistically studied the regulatory roles of lysine acetylation by analyzing the Gene Ontology (GO) and InterPro annotations. Combined with protein-protein interaction information, we systematically discovered a potential human lysine acetylation network (HLAN) among histone acetyltransferases (HATs), substrates and histone deacetylases (HDACs). In particular, there are 1862 triplet relationships of HAT-substrate-HDAC retrieved from the HLAN, at least 13 of which were previously experimentally verified. The online services of CPLA database was implemented in PHP + MySQL + JavaScript, while the local packages were developed in JAVA 1.5 (J2SE 5.0). The CPLA database is freely available for all users at: http://cpla.biocuckoo.org.

[Effect of glucose and lactose on the utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469].

Science.gov (United States)

Benito de Cárdenas, I L; Medina, R; Oliver, G

1992-01-01

The utilization of citrate by Lactobacillus casei subsp. rhamnosus ATCC 7469 in a complex medium containing glucose, lactose or citrate was investigated, as an approach to the question of the transport of this acid and the possible relationship with the production of flavour compounds (diacetyl and acetoin). This lactobacillus uses citrate as an energy source in the absence of carbohydrates. External pH and growth increases when citrate is added to complex medium. The presence of citrate does not affect glucose uptake. L. casei ATCC 7469 possibly uses a transport system for citrate utilization, and citrate uptake seems to be under glucose or lactose control. Lactose only inhibits the entrance of citrate at high concentration while the utilization of this acid was negatively regulated by low glucose concentration.

Comprehensive Proteomic Analysis of Lysine Acetylation in the Foodborne Pathogen Trichinella spiralis

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Yong Yang

2018-01-01

Full Text Available Lysine acetylation is a dynamic and highly conserved post-translational modification that plays a critical role in regulating diverse cellular processes. Trichinella spiralis is a foodborne parasite with a considerable socio-economic impact. However, to date, little is known regarding the role of lysine acetylation in this parasitic nematode. In this study, we utilized a proteomic approach involving anti-acetyl lysine-based enrichment and highly sensitive mass spectrometry to identify the global acetylated proteome and investigate lysine acetylation in T. spiralis. In total, 3872 lysine modification sites were identified in 1592 proteins that are involved in a wide variety of biological processes. Consistent with the results of previous studies, a large number of the acetylated proteins appear to be involved in metabolic and biosynthetic processes. Interestingly, according to the functional enrichment analysis, 29 acetylated proteins were associated with phagocytosis, suggesting an important role of lysine acetylation in this process. Among the identified proteins, 15 putative acetylation motifs were detected. The presence of serine downstream of the lysine acetylation site was commonly observed in the regions surrounding the sites. Moreover, protein interaction network analysis revealed that various interactions are regulated by protein acetylation. These data represent the first report of the acetylome of T. spiralis and provide an important resource for further explorations of the role of lysine acetylation in this foodborne pathogen.

Free Rhodium (II) citrate and rhodium (II) citrate magnetic carriers as potential strategies for breast cancer therapy

Science.gov (United States)

2011-01-01

Background Rhodium (II) citrate (Rh2(H2cit)4) has significant antitumor, cytotoxic, and cytostatic activity on Ehrlich ascite tumor. Although toxic to normal cells, its lower toxicity when compared to carboxylate analogues of rhodium (II) indicates Rh2(H2cit)4 as a promising agent for chemotherapy. Nevertheless, few studies have been performed to explore this potential. Superparamagnetic particles of iron oxide (SPIOs) represent an attractive platform as carriers in drug delivery systems (DDS) because they can present greater specificity to tumor cells than normal cells. Thus, the association between Rh2(H2cit)4 and SPIOs can represent a strategy to enhance the former's therapeutic action. In this work, we report the cytotoxicity of free rhodium (II) citrate (Rh2(H2cit)4) and rhodium (II) citrate-loaded maghemite nanoparticles or magnetoliposomes, used as drug delivery systems, on both normal and carcinoma breast cell cultures. Results Treatment with free Rh2(H2cit)4 induced cytotoxicity that was dependent on dose, time, and cell line. The IC50 values showed that this effect was more intense on breast normal cells (MCF-10A) than on breast carcinoma cells (MCF-7 and 4T1). However, the treatment with 50 μM Rh2(H2cit)4-loaded maghemite nanoparticles (Magh-Rh2(H2cit)4) and Rh2(H2cit)4-loaded magnetoliposomes (Lip-Magh-Rh2(H2cit)4) induced a higher cytotoxicity on MCF-7 and 4T1 than on MCF-10A (p rhodium (II) citrate-loaded maghemite nanoparticles and magnetoliposomes induced more specific cytotoxicity on breast carcinoma cells than on breast normal cells, which is the opposite of the results observed with free Rh2(H2cit)4 treatment. Thus, magnetic nanoparticles represent an attractive platform as carriers in Rh2(H2cit)4 delivery systems, since they can act preferentially in tumor cells. Therefore, these nanopaticulate systems may be explored as a potential tool for chemotherapy drug development. PMID:21443799

Effects and mechanisms of action of sildenafil citrate in human chorionic arteries

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Lynch Tadhg

2009-04-01

Full Text Available Abstract Objectives Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. Study Design Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. Results Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. Conclusion Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

Effects and mechanisms of action of sildenafil citrate in human chorionic arteries.

LENUS (Irish Health Repository)

Maharaj, Chrisen H

2009-01-01

OBJECTIVES: Sildenafil citrate, a specific phosphodiesterase-5 inhibitor, is increasingly used for pulmonary hypertension in pregnancy. Sildenafil is also emerging as a potential candidate for the treatment of intra-uterine growth retardation and for premature labor. Its effects in the feto-placental circulation are not known. Our objectives were to determine whether phosphodiesterase-5 is present in the human feto-placental circulation, and to characterize the effects and mechanisms of action of sildenafil citrate in this circulation. STUDY DESIGN: Ex vivo human chorionic plate arterial rings were used in all experiments. The presence of phosphodiesterase-5 in the feto-placental circulation was determined by western blotting and immunohistochemical staining. In a subsequent series of pharmacologic studies, the effects of sildenafil citrate in pre-constricted chorionic plate arterial rings were determined. Additional studies examined the role of cGMP and nitric oxide in mediating the effects of sildenafil. RESULTS: Phosphodiesterase-5 mRNA and protein was demonstrated in human chorionic plate arteries. Immunohistochemistry demonstrated phosphodiesterase-5 within the arterial muscle layer. Sildenafil citrate produced dose dependent vasodilatation at concentrations at and greater than 10 nM. Both the direct cGMP inhibitor methylene blue and the cGMP-dependent protein kinase inhibitor Rp-8-Br-PET-cGMPS significantly attenuated the vasodilation produced by sildenafil citrate. Inhibition of NO production with L-NAME did not attenuate the vasodilator effects of sildenafil. In contrast, sildenafil citrate significantly enhanced the vasodilation produced by the NO donor sodium nitroprusside. CONCLUSION: Phosphodiesterase-5 is present in the feto-placental circulation. Sildenafil citrate vasodilates the feto-placental circulation via a cGMP dependent mechanism involving increased responsiveness to NO.

The Metabolic Fate of Deoxynivalenol and Its Acetylated Derivatives in a Wheat Suspension Culture: Identification and Detection of DON-15-O-Glucoside, 15-Acetyl-DON-3-O-Glucoside and 15-Acetyl-DON-3-Sulfate

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Clemens Schmeitzl

2015-08-01

Full Text Available Deoxynivalenol (DON is a protein synthesis inhibitor produced by the Fusarium species, which frequently contaminates grains used for human or animal consumption. We treated a wheat suspension culture with DON or one of its acetylated derivatives, 3-acetyl-DON (3-ADON, 15-acetyl-DON (15-ADON and 3,15-diacetyl-DON (3,15-diADON, and monitored the metabolization over a course of 96 h. Supernatant and cell extract samples were analyzed using a tailored LC-MS/MS method for the quantification of DON metabolites. We report the formation of tentatively identified DON-15-O-β-D-glucoside (D15G and of 15-acetyl-DON-3-sulfate (15-ADON3S as novel deoxynivalenol metabolites in wheat. Furthermore, we found that the recently identified 15-acetyl-DON-3-O-β-D-glucoside (15-ADON3G is the major metabolite produced after 15-ADON challenge. 3-ADON treatment led to a higher intracellular content of toxic metabolites after six hours compared to all other treatments. 3-ADON was exclusively metabolized into DON before phase II reactions occurred. In contrast, we found that 15-ADON was directly converted into 15-ADON3G and 15-ADON3S in addition to metabolization into deoxynivalenol-3-O-β-D-glucoside (D3G. This study highlights significant differences in the metabolization of DON and its acetylated derivatives.

Evaluating the efficacy of citrate anticoagulation during CRRT in cardiac patients

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А. М. Караськов

2015-10-01

Full Text Available Systemic anticoagulation during renal replacement therapy in cardiac patients increases the risk of postoperative complications. Citrate anticoagulation is a promising alternative. The objective of our study was to evaluate the efficacy of citrate anticoagulation and its influence on the parameters of hemostasis and complications.

N-Acetyl-4-aminophenol (paracetamol), N-acetyl-2-aminophenol and acetanilide in urine samples from the general population, individuals exposed to aniline and paracetamol users.

Science.gov (United States)

Dierkes, Georg; Weiss, Tobias; Modick, Hendrik; Käfferlein, Heiko Udo; Brüning, Thomas; Koch, Holger M

2014-01-01

Epidemiological studies suggest associations between the use of N-acetyl-4-aminophenol (paracetamol) during pregnancy and increased risks of reproductive disorders in the male offspring. Previously we have reported a ubiquitous urinary excretion of N-acetyl-4-aminophenol in the general population. Possible sources are (1) direct intake of paracetamol through medication, (2) paracetamol residues in the food chain and (3) environmental exposure to aniline or related substances that are metabolized into N-acetyl-4-aminophenol. In order to elucidate the origins of the excretion of N-acetyl-4-aminophenol in urine and to contribute to the understanding of paracetamol and aniline metabolism in humans we developed a rapid, turbulent-flow HPLC-MS/MS method with isotope dilution for the simultaneous quantification of N-acetyl-4-aminophenol and two other aniline related metabolites, N-acetyl-2-aminophenol and acetanilide. We applied this method to three sets of urine samples: (1) individuals with no known exposure to aniline and also no recent paracetamol medication; (2) individuals after occupational exposure to aniline but no paracetamol medication and (3) paracetamol users. We confirmed the omnipresent excretion of N-acetyl-4-aminophenol. Additionally we revealed an omnipresent excretion of N-acetyl-2-aminophenol. In contrast, acetanilide was only found after occupational exposure to aniline, not in the general population or after paracetamol use. The results lead to four preliminary conclusions: (1) other sources than aniline seem to be responsible for the major part of urinary N-acetyl-4-aminophenol in the general population; (2) acetanilide is a metabolite of aniline in man and a valuable biomarker for aniline in occupational settings; (3) aniline baseline levels in the general population measured after chemical hydrolysis do not seem to originate from acetanilide and hence not from a direct exposure to aniline itself and (4) N-acetyl-2-aminophenol does not seem to be

Uranium Rirang ore processing: extraction of uranium from Rirang ore digestion solution with tributyl phosphate

International Nuclear Information System (INIS)

Arief, E. R.; Zahardi; Susilaningtyas

1998-01-01

Uranium is extracted from Rirang ore acid digestion solution containing rare earths. A mixture of tributyl phosphate solvent and kerosene diluent is employed. Several parameters of solvent extraction have been studied included aqueous to organic phase ratio, H 2 O 2 reductor concentration and Tbp concentration in the solvent mixture, as well as the aqueous to organic phase ratio in the stripping process. The optimum conditions for the extraction step include the use of 25% H 2 O 2 (v/v), one to one aqueous to organic ratio, and 40% Tbp in kerosene. The extraction recovery for U, RE, Th, and PO 4 3 - are 99%, 4%, 70%, and 30%, respectively. The stripping step optimum conditions include the use of one to five organic to aqueous phase ratio 0.24 N HNO 3 . and the stripping recovery for U, RE, Th, and PO 4 3 - are 84%, 80%, 72%, and 83%, respectively

Effect of clomifene citrate plus metformin and clomifene citrate plus placebo on induction of ovulation in women with newly diagnosed polycystic ovary syndrome: randomised double blind clinical trial

NARCIS (Netherlands)

Moll, Etelka; Bossuyt, Patrick M. M.; Korevaar, Johanna C.; Lambalk, Cornelis B.; van der Veen, Fulco

2006-01-01

OBJECTIVE: To compare the effectiveness of clomifene citrate plus metformin and clomifene citrate plus placebo in women with newly diagnosed polycystic ovary syndrome. DESIGN: Randomised clinical trial. SETTING: Multicentre trial in 20 Dutch hospitals. PARTICIPANTS: 228 women with polycystic ovary

Structural and functional annotation of citrate synthase from Aspergillus niger ANJ-120.

Science.gov (United States)

Mustafa, Ghulam; Arif, Rawaba; Bukhari, Shazia Anwer; Ali, Muhammad; Sharif, Sumaira; Atta, Asia

2018-03-01

Citrate synthase (CS) is involved in citric acid biosynthesis which is a well-established metabolic pathway. The condensation of acetyl-CoA with oxaloacetate is catalyzed by CS. Citric acid (CA) has a number of applications in pharmaceutical industry. CA in combination with bicarbonates is used as an effervescent in the preparations of tablets and powders. It has also been used as an anticoagulant and acidulant to form mild astringent. In current study, detailed structural and functional analyses of CS protein were carried out using various bioinformatics tools. Structural modeling was also done by building 3D model of CS from Aspergillus niger ANJ-120 using Modeller 9.16 software. The 3D Model was then evaluated using different online approaches. Furthermore, superimposition of query and template structures, Root Mean Squared Deviation and visualization of generated model were done through UCSF Chimera 1.5.3. Even though various roles of CS protein were already known and verified experimentally, here we presented a structural analysis of CS protein. The structural investigation of CS protein will be helpful for protein engineering strategies and understanding the interactions among proteins. Due to large number of applications, the production of citric acid by A. niger and its bioinformatics studies will offer substantial improvement in commercial scale intensification of this useful product.

SILDENAFIL CITRATE INDUCED RETINAL TOXICITY-ELECTRORETINOGRAM, OPTICAL COHERENCE TOMOGRAPHY, AND ADAPTIVE OPTICS FINDINGS.

Science.gov (United States)

Yanoga, Fatoumata; Gentile, Ronald C; Chui, Toco Y P; Freund, K Bailey; Fell, Millie; Dolz-Marco, Rosa; Rosen, Richard B

2018-02-27

To report a case of persistent retinal toxicity associated with a high dose of sildenafil citrate intake. Single retrospective case report. A 31-year-old white man with no medical history presented with complaints of bilateral multicolored photopsias and erythropsia (red-tinted vision), shortly after taking sildenafil citrate-purchased through the internet. Patient was found to have cone photoreceptor damage, demonstrated using electroretinogram, optical coherence tomography, and adaptive optics imaging. The patient's symptoms and the photoreceptor structural changes persisted for several months. Sildenafil citrate is a widely used erectile dysfunction medication that is typically associated with transient visual symptoms in normal dosage. At high dosage, sildenafil citrate can lead to persistent retinal toxicity in certain individuals.

Studies on sildenafil citrate (Viagra) interaction with DNA using electrochemical DNA biosensor.

Science.gov (United States)

Rauf, Sakandar; Nawaz, Haq; Akhtar, Kalsoom; Ghauri, Muhammad A; Khalid, Ahmad M

2007-05-15

The interaction of sildenafil citrate (Viagra) with DNA was studied by using an electrochemical DNA biosensor. The binding mechanism of sildenafil citrate was elucidated by using constant current potentiometry and differential pulse voltammetry at DNA-modified glassy carbon electrode. The decrease in the guanine oxidation peak area or peak current was used as an indicator for the interaction in 0.2M acetate buffer (pH 5). The binding constant (K) values obtained were 2.01+/-0.05 x 10(5) and 1.97+/-0.01 x 10(5)M(-1) with constant current potentiometry and differential pulse voltammetry, respectively. A linear dependence of the guanine peak area or peak current was observed within the range of 1-40 microM sildenafil citrate with slope=-2.74 x 10(-4)s/microM, r=0.989 and slope=-2.78 x 10(-3)microA/microM, r=0.995 by using constant current potentiometry and differential pulse voltammetry, respectively. Additionally, binding constant values for sildenafil citrate-DNA interaction were determined for the pH range of 4-8 and in biological fluids (serum and urine) at pH 5. The influence of sodium and calcium ions was also studied to elucidate the mechanism of sildenafil citrate-DNA interaction under different solution conditions. The present study may prove to be helpful in extending our understanding of the anticancer activity of sildenafil citrate from cellular to DNA level.

76 FR 19997 - Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn...

Science.gov (United States)

2011-04-11

...] Determination That FENTORA (Fentanyl Citrate) Buccal Tablet, 300 Micrograms, Was Not Withdrawn From Sale for... Food and Drug Administration (FDA) has determined that FENTORA (fentanyl citrate) buccal tablet, 300... allow FDA to approve abbreviated new drug applications (ANDAs) for fentanyl citrate buccal tablet, 300...

Determination of the barrier height for acetyl radical dissociation from acetyl chloride photodissociation at 235 nm using velocity map imaging.

Science.gov (United States)

Tang, Xiaonan; Ratliff, Britni J; FitzPatrick, Benjamin L; Butler, Laurie J

2008-12-18

This work uses velocity map imaging to determine the barrier height for acetyl radical, CH3CO, dissociation to CH3 + CO. Photodissociation of acetyl chloride at 235 nm generates acetyl radicals with an internal energy distribution spanning this barrier. We determine the velocity and internal energy distribution of all nascent acetyl radicals, stable and unstable, by measuring the velocities of the Cl(2P3/2) and Cl(2P1/2) cofragments. These Cl cofragments are detected with 2 + 1 resonance-enhanced multiphoton ionization (REMPI) in a spin-orbit branching ratio Cl(2P3/2):Cl(2P1/2) of 3.3 +/- 0.2. Using 157 nm photoionization, we then detect the recoil velocities of the energetically stable acetyl radicals. The radicals and momentum matched Cl atoms evidence parallel angular distributions. Comparison of the total recoil translational energy distribution P(E(T)) for all radicals to that obtained from the detection of stable radicals yields an onset for dissociation at a translational energy of 25.0 +/- 0.4 kcal/mol. From this onset we can calculate the barrier height for CH3CO --> CH3 + CO, but this relies on prior determinations of the C-Cl bond energy of acetyl chloride. Using an experimental bond dissociation energy of 83.4 +/- 0.2 kcal/mol yields a dissociation barrier of 14.2 +/- 0.5 kcal/mol. Our data evidence that a portion of the acetyl radicals formed with total internal energy above the barrier are stable due to the partitioning of energy into rotation during the C-Cl bond fission of the precursor. Thus, the internal energy onset for dissociation is not as sharp as was assumed in prior determinations of the barrier. The experimentally determined onset is compared with that predicted from electronic structure calculations at the G3//B3LYP and CCSD(T) levels of theory.

Nitrate Protects Cucumber Plants Against Fusarium oxysporum by Regulating Citrate Exudation.

Science.gov (United States)

Wang, Min; Sun, Yuming; Gu, Zechen; Wang, Ruirui; Sun, Guomei; Zhu, Chen; Guo, Shiwei; Shen, Qirong

2016-09-01

Fusarium wilt causes severe yield losses in cash crops. Nitrogen plays a critical role in the management of plant disease; however, the regulating mechanism is poorly understood. Using biochemical, physiological, bioinformatic and transcriptome approaches, we analyzed how nitrogen forms regulate the interactions between cucumber plants and Fusarium oxysporum f. sp. cucumerinum (FOC). Nitrate significantly suppressed Fusarium wilt compared with ammonium in both pot and hydroponic experiments. Fewer FOC colonized the roots and stems under nitrate compared with ammonium supply. Cucumber grown with nitrate accumulated less fusaric acid (FA) after FOC infection and exhibited increased tolerance to chemical FA by decreasing FA absorption and transportation in shoots. A lower citrate concentration was observed in nitrate-grown cucumbers, which was associated with lower MATE (multidrug and toxin compound extrusion) family gene and citrate synthase (CS) gene expression, as well as lower CS activity. Citrate enhanced FOC spore germination and infection, and increased disease incidence and the FOC population in ammonium-treated plants. Our study provides evidence that nitrate protects cucumber plants against F. oxysporum by decreasing root citrate exudation and FOC infection. Citrate exudation is essential for regulating disease development of Fusarium wilt in cucumber plants. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Post-Dilution on Line Haemodiafiltration with Citrate Dialysate: First Clinical Experience in Chronic Dialysis Patients

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Vincenzo Panichi

2013-01-01

Full Text Available Background. Citrate has anticoagulative properties and favorable effects on inflammation, but it has the potential hazards of inducing hypocalcemia. Bicarbonate dialysate (BHD replacing citrate for acetate is now used in chronic haemodialysis but has never been tested in postdilution online haemodiafiltration (OL-HDF. Methods. Thirteen chronic stable dialysis patients were enrolled in a pilot, short-term study. Patients underwent one week (3 dialysis sessions of BHD with 0.8 mmol/L citrate dialysate, followed by one week of postdilution high volume OL-HDF with standard bicarbonate dialysate, and one week of high volume OL-HDF with 0.8 mmol/L citrate dialysate. Results. In citrate OL-HDF pretreatment plasma levels of C-reactive protein and β2-microglobulin were significantly reduced; intra-treatment plasma acetate levels increased in the former technique and decreased in the latter. During both citrate techniques (OL-HDF and HD ionized calcium levels remained stable within the normal range. Conclusions. Should our promising results be confirmed in a long-term study on a wider population, then OL-HDF with citrate dialysate may represent a further step in improving dialysis biocompatibility.

Evaluation of gels obtained from acetylation of chitosan in heterogeneous medium

International Nuclear Information System (INIS)

Garcia, Rosangela Balaban; Silva, Dayse Luzia Pinheiro da; Costa, Marta

2008-01-01

Chitosan was acetylated during 2, 5 and 10 h and physical gels were obtained at different polymer concentrations in N,N-dimethylacetamide containing 5% of LiCl. Acetylation was confirmed by infrared spectroscopy and 13 C NMR, and degrees of acetylation in the range of 0.82-0.91 were determined by NMR. The O-acetylation degree (0.12-0.15) was exclusively determined by a volumetric method. Rheological studies showed that the storage modulus values were smaller for the more acetylated samples and increased with the temperature and the polymer concentration. All the gels presented storage modulus superior to loss modulus, evidencing more elastic than viscous characteristics. The results obtained in this work suggest a gelation process based on a balance between O and N-acetylation and intermolecular bonds. (author)

Effect of food deprivation and hormones of glucose homeostasis on the acetyl CoA carboxylase activity in mouse brain: a potential role of acc in the regulation of energy balance

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Mukherjee Amrita

2006-02-01

Full Text Available Abstract We studied the regulation of brain acetyl CoA carboxylase (ACC activity during food deprivation and under the influence of hormones of glucose homeostasis: glucagon and insulin. Mice were deprived of food and water for time periods of 1, 3, 6, 9, 12 and 24 hours and were then allowed to re-feed for 5, 30 and 60 minutes. Mice that were deprived for up to 6 h, and then re-fed for 60 min, consumed the same amount of food compared to the ad libitum (control animals. However, after 9 h of deprivation, mice consumed only 50% of food present even after 1 h of re-feeding, compared to the controls. The ACC activity was measured in the whole mouse brain of controls and after 1, 3, 6, 9, 12, and 24 h of food deprivation. Brain extracts assayed from control mice expressed an ACC activity of 0.988 ± 0.158 fmol/min/mg tissue without citrate and 0.941 ± 0.175 fmol/min/mg tissue with citrate. After 1 h of food deprivation, the total ACC activity without citrate decreased to 0.575 ± 0.087 fmol/min/mg and in the presence of citrate, 0.703 ± 0.036 fmol/min/mg activity was measured. The citrate-dependent ACC activity decreased over time, with only 0.478 ± 0.117 fmol/min/mg of activity remaining after 24 h. Intraperitoneal (i.p. injections of insulin, glucagon and phosphate buffered saline (PBS were performed and whole brain ACC activity measured. After hormone administration, there were no significant differences in ACC activity in the presence of citrate. However, in the absence of citrate, there was a significant 20% decrease in ACC activity with glucagon (1.36 ± 0.09 fmol/min/mg and a 33% increase with insulin (2.49 ± 0.11 fmol/min/mg injections compared to PBS controls (1.67 ± 0.08 fmol/min/mg. Neuropeptide Y (NPY levels of corresponding brain extracts were measured by ELISA (OD using anti-NPY antibody and showed an 18% decrease upon insulin injection (0.093 ± 0.019 and a 50% increase upon glucagon injection (0.226 ± 0.084 as compared to

Electrospray ionization of uranyl-citrate complexes

Science.gov (United States)

Somogyi, Árpád; Pasilis, Sofie P.; Pemberton, Jeanne E.

2007-09-01

Results presented here demonstrate the usefulness of electrospray ionization and gas-phase ion-molecule reactions to predict structural and electronic differences in complex inorganic ions. Electrospray ionization of uranyl citrate solutions generates positively and negatively charged ions that participate in further ion-molecule reactions in 3D ion trap and FT-ICR mass analyzers. Most ions observed are derived from the major solution uranyl-citrate complexes and involve species of {(UO2)2Cit2}2-, (UO2)3Cit2, and {(UO2)3Cit3}3-, where Cit indicates the citrate trianion, C6H5O73-. In a 3D ion trap operated at relatively high pressure, complex adducts containing solvent molecules, alkali and ammonium cations, and nitrate or chloride anions are dominant, and proton/alkali cation (Na+, K+) exchange is observed for up to six exchangeable protons in an excess of alkali cations. Adduct formation in a FT-ICR cell that is operated at lower pressures is less dominant, and direct detection of positive and negative ions of the major solution complexes is possible. Multiply charged ions are also detected, suggesting the presence of uranium in different oxidation states. Changes in uranium oxidation state are detected by He-CID and SORI-CID fragmentation, and certain fragments undergo association reactions in trapping analyzers, forming "exotic" species such as [(UO2)4O3]-, [(UO2)4O4]-, and [(UO2)4O5]-. Ion-molecule reactions with D2O in the FT-ICR cell indicate substantial differences in H/D exchange rate and D2O accommodation for different ion structures and charge states. Most notably, the positively charged ions [H2(UO2)2Cit2(H)]+ and [(UO2)2(Cit)]+ accommodate two and three D2O molecules, respectively, which reflects well the structural differences, i.e., tighter uranyl-citrate coordination in the former ion than in the latter. The corresponding negatively charged ions accommodate zero or two D2O molecules, which can be rationalized using suggested solution phase structures

Intrinsic Tau Acetylation Is Coupled to Auto-Proteolytic Tau Fragmentation.

Directory of Open Access Journals (Sweden)

Todd J Cohen

Full Text Available Tau proteins are abnormally aggregated in a range of neurodegenerative tauopathies including Alzheimer's disease (AD. Recently, tau has emerged as an extensively post-translationally modified protein, among which lysine acetylation is critical for normal tau function and its pathological aggregation. Here, we demonstrate that tau isoforms have different propensities to undergo lysine acetylation, with auto-acetylation occurring more prominently within the lysine-rich microtubule-binding repeats. Unexpectedly, we identified a unique intrinsic property of tau in which auto-acetylation induces proteolytic tau cleavage, thereby generating distinct N- and C-terminal tau fragments. Supporting a catalytic reaction-based mechanism, mapping and mutagenesis studies showed that tau cysteines, which are required for acetyl group transfer, are also essential for auto-proteolytic tau processing. Further mass spectrometry analysis identified the C-terminal 2nd and 4th microtubule binding repeats as potential sites of auto-cleavage. The identification of acetylation-mediated auto-proteolysis provides a new biochemical mechanism for tau self-regulation and warrants further investigation into whether auto-catalytic functions of tau are implicated in AD and other tauopathies.

Histones of Chlamydomonas reinhardtii. Synthesis, acetylation, and methylation

International Nuclear Information System (INIS)

Waterborg, J.H.; Robertson, A.J.; Tatar, D.L.; Borza, C.M.; Davie, J.R.

1995-01-01

Histones of the green alga Chlamydomonas reinhardtii were prepared by a new method and fractionated by reversed-phase high-performance liquid chromatography. Acid-urea-Triton gel analysis and tritiated acetate labeling demonstrated high levels of steady-state acetylation for the single histone H3 protein, in contrast to low levels on histones H4 and H2B. Twenty percent of histone H3 is subject to dynamic acetylation with, on average, three acetylated lysine residues per protein molecule. Histone synthesis in light-dark-synchronized cultures was biphasic with pattern differences between two histone H1 variants, between two H2A variants, and between H2B and ubiquitinated H2B. Automated protein sequence analysis of histone H3 demonstrated a site-specific pattern of steady-state acetylation between 7 and 17% at five of the six amino-terminal lysines and of monomethylation between 5 and 81% at five of the eight amino-terminal lysines in a pattern that may limit dynamic acetylation. An algal histone H3 sequence was confirmed by protein sequencing with a since threonine as residue 28 instead of the serine(28)-alanine(29) sequence, present in all other known plant and animal H3 histones

Synthesis of O-[11C]acetyl CoA, O-[11C]acetyl-L-carnitine, and L-[11C]carnitine labelled in specific positions, applied in PET studies on rhesus monkey

International Nuclear Information System (INIS)

Jacobson, Gunilla B.; Watanabe, Yasuyoshi; Valind, Sven; Kuratsune, Hirohiko; Laangstroem, Bengt

1997-01-01

The syntheses of L-carnitine, O-acetyl CoA, and O-acetyl-L-carnitine labelled with 11 C at the 1- or 2-position of the acetyl group or the N-methyl position of carnitine, using the enzymes acetyl CoA synthetase and carnitine acetyltransferase, are described. With a total synthesis time of 45 min, O-[1- 11 C]acetyl CoA and O-[2- 11 C]acetyl CoA was obtained in 60-70% decay-corrected radiochemical yield, and O-[1- 11 C]acetyl-L-carnitine and O-[2- 11 C]acetyl-L-carnitine in 70-80% yield, based on [1- 11 C]acetate or [2- 11 C]acetate, respectively. By an N-methylation reaction with [ 11 C]methyl iodide, L-[methyl- 11 C]carnitine was obtained within 30 min, and O-acetyl-L-[methyl- 11 C]carnitine within 40 min, giving a decay-corrected radiochemical yield of 60% and 40-50%, respectively, based on [ 11 C]methyl iodide. Initial data of the kinetics of the different 11 C-labelled L-carnitine and acetyl-L-carnitines in renal cortex of anaesthetized monkey (Macaca mulatta) are presented

21 CFR 172.372 - N-Acetyl-L-methionine.

Science.gov (United States)

2010-04-01

... and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.372 N-Acetyl-L-methionine. The food additive N-acetyl-L...

Processing Conditions, Thermal and Mechanical Responses of Stretchable Poly (Lactic Acid)/Poly (Butylene Succinate) Films.

Science.gov (United States)

Fortunati, Elena; Puglia, Debora; Iannoni, Antonio; Terenzi, Andrea; Kenny, José Maria; Torre, Luigi

2017-07-16

Poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) based films containing two different plasticizers [Acetyl Tributyl Citrate (ATBC) and isosorbide diester (ISE)] at three different contents (15 wt %, 20 wt % and 30 wt %) were produced by extrusion method. Thermal, morphological, mechanical and wettability behavior of produced materials was investigated as a function of plasticizer content. Filmature parameters were also adjusted and optimized for different formulations, in order to obtain similar thickness for different systems. Differential scanning calorimeter (DSC) results and evaluation of solubility parameter confirmed that similar miscibility was obtained for ATBC and ISE in PLA, while the two selected plasticizers resulted as not efficient for plasticization of PBS, to the limit that the PBS-30ATBC resulted as not processable. On the basis of these results, isosorbide-based plasticizer was considered a suitable agent for modification of a selected blend (PLA/PBS 80:20) and two mixing approaches were used to identify the role of ISE in the plasticization process: results from mechanical analysis confirmed that both produced PLA-PBS blends (PLA85-ISE15)-PBS20 and (PLA80-PBS20)-ISE15 could guarantee advantages in terms of deformability, with respect to the PLA80-PBS20 reference film, suggesting that the promising use of these stretchable PLA-PBS based films plasticized with isosorbide can provide novel solutions for food packaging applications.

Study on the Antimicrobial Properties of Citrate-Based Biodegradable Polymers

Directory of Open Access Journals (Sweden)

Lee-Chun eSu

2014-07-01

Full Text Available 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 (POC showed approximately 70-80% suppression to microbe proliferation, owing to its relatively higher ratio of citric acid contents. Crosslinked urethane-doped polyester elastomers (CUPEs and biodegradable photoluminescent polymers (BPLPs 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 they are unique beneficial materials for wound dressing, tissue engineering, and other potential medical applications where antimicrobial property is desired.

Inhibition of citric acid accumulation by manganese ions in Aspergillus niger mutants with reduced citrate control of phosphofructokinase

Energy Technology Data Exchange (ETDEWEB)

Schreferl, G.; Kubicek, C.P.; Roehr, M.

1986-03-01

Mutant strains of Aspergillus niger with reduced citrate control of carbohydrate catabolism (cic mutants) grow faster than the parent strain on media containing 5% (wt/vol) citrate. The mutants tolerated a higher intracellular citrate concentration than the parent strain. One mutant (cic-7/3) contained phosphofructokinase activity significantly less sensitive towards citrate than the enzyme from the parent strain. When this mutant was grown under citrate accumulating conditions, acidogenesis was far less sensitive to inhibition by Mn/sup 2 +/ than in the parent strain. Some of the cic mutants also showed altered citrate inhibition of NADP-specific isocitrate dehydrogenase.

Prediction of Nepsilon-acetylation on internal lysines implemented in Bayesian Discriminant Method.

Science.gov (United States)

Li, Ao; Xue, Yu; Jin, Changjiang; Wang, Minghui; Yao, Xuebiao

2006-12-01

Protein acetylation is an important and reversible post-translational modification (PTM), and it governs a variety of cellular dynamics and plasticity. Experimental identification of acetylation sites is labor-intensive and often limited by the availability of reagents such as acetyl-specific antibodies and optimization of enzymatic reactions. Computational analyses may facilitate the identification of potential acetylation sites and provide insights into further experimentation. In this manuscript, we present a novel protein acetylation prediction program named PAIL, prediction of acetylation on internal lysines, implemented in a BDM (Bayesian Discriminant Method) algorithm. The accuracies of PAIL are 85.13%, 87.97%, and 89.21% at low, medium, and high thresholds, respectively. Both Jack-Knife validation and n-fold cross-validation have been performed to show that PAIL is accurate and robust. Taken together, we propose that PAIL is a novel predictor for identification of protein acetylation sites and may serve as an important tool to study the function of protein acetylation. PAIL has been implemented in PHP and is freely available on a web server at: http://bioinformatics.lcd-ustc.org/pail.

Prediction of Nε-acetylation on internal lysines implemented in Bayesian Discriminant Method

Science.gov (United States)

Li, Ao; Xue, Yu; Jin, Changjiang; Wang, Minghui; Yao, Xuebiao

2007-01-01

Protein acetylation is an important and reversible post-translational modification (PTM), and it governs a variety of cellular dynamics and plasticity. Experimental identification of acetylation sites is labor-intensive and often limited by the availability reagents such as acetyl-specific antibodies and optimization of enzymatic reactions. Computational analyses may facilitate the identification of potential acetylation sites and provide insights into further experimentation. In this manuscript, we present a novel protein acetylation prediction program named PAIL, prediction of acetylation on internal lysines, implemented in a BDM (Bayesian Discriminant Method) algorithm. The accuracies of PAIL are 85.13%, 87.97% and 89.21% at low, medium and high thresholds, respectively. Both Jack-Knife validation and n-fold cross validation have been performed to show that PAIL is accurate and robust. Taken together, we propose that PAIL is a novel predictor for identification of protein acetylation sites and may serve as an important tool to study the function of protein acetylation. PAIL has been implemented in PHP and is freely available on a web server at: http://bioinformatics.lcd-ustc.org/pail. PMID:17045240

Bio-inspired citrate functionalized apatite coating on rapid prototyped titanium scaffold

Energy Technology Data Exchange (ETDEWEB)

Yu, Peng [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Lu, Fang [School of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006 (China); Zhu, Wenjun [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Wang, Di [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhu, Xiaojing [Department of Prosthodontics, Guanghua School of Stomatology, Guang Dong Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou 510055 (China); Tan, Guoxin, E-mail: tanguoxin@126.com [Institute of Chemical Engineering and Light Industry, Guangdong University of Technology, Guangzhou 510006 (China); Wang, Xiaolan [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China); Zhang, Yu; Li, Lihua [General Hospital of Guangzhou Military Command of PLA, Guangzhou 510010 (China); Ning, Chengyun, E-mail: imcyning@scut.edu.cn [National engineering research center for tissue restoration and reconstruction, South China University of Technology, Guangzhou 510641 (China)

2014-09-15

Highlights: • Designed and reproducible porous titanium scaffolds were produced. • Hydrophilic nanoporous film was built on scaffold. • Apatite coating was deposited on scaffold under the modulation of citrate ions. • Citrate ions could affect CO{sub 3}{sup 2−} incorporation in apatite coatings. - Abstract: Scaffold functionalized with appropriate osteogenic coatings can significantly improve implant-bone response. In this study, with designed model and optimized manufacture parameters, reproducible and precise titanium scaffolds were produced. Reconstructed three-dimensional image and sectional structure of the scaffold were examined by micro-computed tomography and relative software. Alkali treatment was carried out on these manufactured porous scaffolds to produce nanoporous hydrophilic film. After 6 days deposition in simulated body fluid (SBF) containing sodium citrate (SC-SBF), plate-like amorphous calcium phosphate (ACP) coating was deposited on scaffold surface. Ultrasonication tests qualitatively indicated an enhanced adhesion force of apatite coatings deposited in SC-SBF compared to that deposited in SBF. And the effect of citrate ions on the CO{sub 3}{sup 2−} incorporation rate in apatite coating was quantitatively examined by bending vibration of CO{sub 3}{sup 2−} at ∼874 cm{sup −1}. Results indicated the highest carbonate content was obtained at the citrate ion concentration of 6 × 10{sup −5} mol/L in SC-SBF. These three-dimensional porous titanium-apatite hybrid scaffolds are expected to find application in bone tissue regeneration.

Influence of acetylation on the physicochemical properties of ...

African Journals Online (AJOL)

The study investigates the effect of acetylation on the physicochemical properties of composited starches from sweet potato and water yam. Starch was respectively isolated from both sources, dried and subjected to acetylation at different combination. The result shows that the modified starches were of low percentage of ...

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

Science.gov (United States)

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.

Na/K citrate versus sodium bicarbonate in prevention of contrast-induced nephropathy

Directory of Open Access Journals (Sweden)

Sameh Mohamed Abouzeid

2016-01-01

Full Text Available Contrast-induced nephropathy (CIN is one of the important complications of radiographic procedures, especially in patients with chronic kidney disease. It is also one of the common causes of acute kidney injury. The pathogenesis is postulated to be the effect of oxygen- free radicals and hyperosmolar stress on the renal medulla. It is reported that the production of superoxide is most active at acid environment. K/Na citrate is well known as a urine alkalini- zation medium, and this has been evaluated earlier with standard hydration for reduction of CIN and was stated to be efficient. We aimed to determine the efficacy of Na/K citrate in reducing the frequency of CIN in comparison to sodium bicarbonate in patients after coronary angiography. Two hundred and ten patients with renal dysfunction [estimated glomerular filtration rate (eGFR, 60 mL/min/1.73 m2or less] who underwent elective or emergency coronary angiography (CAG with/without percutaneous coronary intervention (PCI at our institution were enrolled into the study. The patients were randomized into two groups, Group 1-Taking Na/K citrate and Group 2-Taking sodium bicarbonate. Radiographic contrast agent iohexol was used. Change in creatinine, percent change in creatinine, percent change in eGFR, change in serum potassium, and urine pH were all compared between the two groups. There was no significant difference for prevention of CIN when comparing the Na/K citrate with sodium bicarbonate solution in patients exposed to CAG with or without PCI. Mean absolute change in eGFR after 48 h after administration of contrast between sodium bicarbonate group and Na/K citrate group was −0.60 ± 1.58 versus −0.71 ± 1.38. Serum potassium decreased postprocedure in the sodium bicarbonate group than in the citrate group (3.90 ± 0.33 vs. 4.14 ± 0.39. Both agents are equally effective in reducing the incidence of CIN, but the citrate would possibly be a safer option for patients at risk of

Regulation of autophagy by cytosolic acetyl-coenzyme A

DEFF Research Database (Denmark)

Mariño, Guillermo; Pietrocola, Federico; Eisenberg, Tobias

2014-01-01

Acetyl-coenzyme A (AcCoA) is a major integrator of the nutritional status at the crossroads of fat, sugar, and protein catabolism. Here we show that nutrient starvation causes rapid depletion of AcCoA. AcCoA depletion entailed the commensurate reduction in the overall acetylation of cytoplasmic p...

Lipids Reprogram Metabolism to Become a Major Carbon Source for Histone Acetylation

DEFF Research Database (Denmark)

McDonnell, Eoin; Crown, Scott B; Fox, Douglas B

2016-01-01

Cells integrate nutrient sensing and metabolism to coordinate proper cellular responses to a particular nutrient source. For example, glucose drives a gene expression program characterized by activating genes involved in its metabolism, in part by increasing glucose-derived histone acetylation....... Here, we find that lipid-derived acetyl-CoA is a major source of carbon for histone acetylation. Using (13)C-carbon tracing combined with acetyl-proteomics, we show that up to 90% of acetylation on certain histone lysines can be derived from fatty acid carbon, even in the presence of excess glucose...

Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

Science.gov (United States)

Liu, JunLi; Wang, YiHu; Song, ShuJun; Wang, XiJie; Qin, YaYa; Si, ShaoYan; Guo, YanChuan

2015-01-01

Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone. Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers. OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels. Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

Directory of Open Access Journals (Sweden)

JunLi Liu

Full Text Available Collagen peptides (CPs and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone.Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8 for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg; OVX + calcium citrate (75 mg/kg. After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers.OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels.Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

A light-up fluorescent probe for citrate detection based on bispyridinum amides with aggregation-induced emission feature.

Science.gov (United States)

Liu, Chenchen; Hang, Yandi; Jiang, Tao; Yang, Ji; Zhang, Xiao; Hua, Jianli

2018-02-01

Citrate is an important intermediate in the citric acid cycle, a vital metabolic pathway for animals, plants and bacteria. It is of great significance to detect its levels in human beings because several diseases may cause the abnormal of citrate. In this paper, a new turn-on fluorescent sensor (TPE-Py) using the classic tetraphenylethylene (TPE) as the aggregation-induced emission (AIE) fluorophore and bipyridinium-based amides as the recognition receptor has been synthesized for the detection of citrate. The probe exhibits good selectivity and sensitivity to citrate with a relatively low detection limit (1.0 × 10 -7 M). The enhancement of the fluorescence is relevant with the AIE property based on the complexation of TPE-Py with citrate caused by the hydrogen bonding and electrostatic interactions between the bipyridinium diamides and citrate, which has been proved by 1 H NMR and mass spectra titration, scanning electronic microscope and dynamic light scattering analyses. More importantly, the quantification of citrate in artificial urine may develop TPE-Py fluorometric probe for the citrate detection in real biosystems. Copyright © 2017 Elsevier B.V. All rights reserved.

Use of 67Ga citrate in the diagnosis of lung cancer

International Nuclear Information System (INIS)

Bogdasarov, Yu.B.; Zajtseva, T.I.; Gabuniya, R.I.; Abramov, V.F.

1981-01-01

A study was of the potentialities of 67 Ga citrate in the diagnosis of lung cancer, in differentiation from benign tumors and chronic inflammatory processes of the lungs. A total of 101 lung cancer patients were examined, of them 64 with central, and 37 with peripheral cancer. The results of radionuclide studies were correlated with those of surgery and with morphological findings. It has been established that in central cancer scintigraphy with 67 Ga citrate gives positive results in 87% of cases, and in peripheral cancer in 89%. This method is of great value for the diagnosis of cancer metastases to the mediastinal lymph nodes. No correlation between the intensity of 67 Ga citrate accumulation in lung tumors and their histological structure has been revealed [ru

Determination of radiation loads from examination of the colon by 67Ga citrate

International Nuclear Information System (INIS)

Mihalova, P.; Buncova, M.; Vrba, T.

2011-01-01

This paper deals with the determination of radiation loads from examination of the colon by gallium citrate. The average calculated committed effective dose after administration of 5 MBq of 67 Ga-citrate is 2.05 mSv.

The impact of citrate introduction at UK syringe exchange programmes: a retrospective cohort study in Cheshire and Merseyside, UK

Directory of Open Access Journals (Sweden)

Wareing Michelle

2007-12-01

Full Text Available Abstract Background In 2003, it became legal in the UK for syringe exchange programmes (SEPs to provide citrate to injecting drug users to solubilise heroin. Little work has been undertaken on the effect of policy change on SEP function. Here, we examine whether the introduction of citrate in Cheshire and Merseyside SEPs has altered the number of heroin/crack injectors accessing SEPs, the frequency at which heroin/crack injectors visited SEPs and the number of syringes dispensed. Methods Eleven SEPs in Cheshire and Merseyside commenced citrate provision in 2003. SEP-specific data for the six months before and six months after citrate was introduced were extracted from routine monitoring systems relating to heroin and crack injectors. Analyses compared all individuals attending pre and post citrate and matched analyses only those individuals attending in both periods (defined as 'longitudinal attenders'. Non-parametric tests were used throughout. Results Neither new (first seen in either six months period nor established clients visited SEPs more frequently post citrate. New clients collected significantly less syringes per visit post citrate, than pre citrate (14.5,10.0; z = 1.992, P Conclusion The introduction of citrate did not negatively affect SEP attendance. 'Longitudinal attenders' visited SEPs more frequently post citrate, providing staff with greater opportunity for intervention and referral. As the number of syringes they collected each visit remained unchanged the total number of clean syringes made available to this group of injectors increased very slightly between the pre and post citrate periods. However, new clients collected significantly less syringes post citrate than pre citrate, possibly due to staff concerns regarding the amount of citrate (and thus syringes to dispense safely to new clients. These concerns should not be allowed to negatively impact on the number of syringes dispensed.

Lysine acetylation targets protein complexes and co-regulates major cellular functions

DEFF Research Database (Denmark)

Choudhary, Chuna Ram; Kumar, Chanchal; Gnad, Florian

2009-01-01

Lysine acetylation is a reversible posttranslational modification of proteins and plays a key role in regulating gene expression. Technological limitations have so far prevented a global analysis of lysine acetylation's cellular roles. We used high-resolution mass spectrometry to identify 3600......, cell cycle, splicing, nuclear transport, and actin nucleation. Acetylation impaired phosphorylation-dependent interactions of 14-3-3 and regulated the yeast cyclin-dependent kinase Cdc28. Our data demonstrate that the regulatory scope of lysine acetylation is broad and comparable with that of other...

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

Directory of Open Access Journals (Sweden)

Audrey Etienne

Full Text Available 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.

A bioinformatics-based overview of protein Lys-Ne-acetylation

Science.gov (United States)

Among posttranslational modifications, there are some conceptual similarities between Lys-N'-acetylation and Ser/Thr/Tyr O-phosphorylation. Herein we present a bioinformatics-based overview of reversible protein Lys-acetylation, including some comparisons with reversible protein phosphorylation. T...

Molecular characterization of microbial population dynamics during sildenafil citrate degradation.

Science.gov (United States)

De Felice, Bruna; Argenziano, Carolina; Guida, Marco; Trifuoggi, Marco; Russo, Francesca; Condorelli, Valerio; Inglese, Mafalda

2009-02-01

Little is known about pharmaceutical and personal care products pollutants (PPCPs), but there is a growing interest in how they might impact the environment and microbial communities. The widespread use of Viagra (sildenafil citrate) has attracted great attention because of the high usage rate, the unpredictable disposal and the unknown potential effects on wildlife and the environment. Until now information regarding the impact of Viagra on microbial community in water environment has not been reported. In this research, for the first time, the genetic profile of the microbial community, developing in a Viagra polluted water environment, was evaluated by means of the 16S and 18S rRNA genes, for bacteria and fungi, respectively, amplified by polymerase chain reaction (PCR) and separated using the denaturing gradient gel electrophoresis (DGGE) technique. The DGGE results revealed a complex microbial community structure with most of the population persisting throughout the experimental period. DNA sequences from bands observed in the different denaturing gradient gel electrophoresis profiles exhibited the highest degree of identity to uncultured bacteria and fungi found previously mainly in polluted environmental and treating bioreactors. Biotransformation ability of sildenafil citrate by the microbial pool was studied and the capability of these microorganisms to detoxify a polluted water ecosystem was assessed. The bacterial and fungal population was able to degrade sildenafil citrate entirely. Additionally, assays conducted on Daphnia magna, algal growth inhibition assay and cell viability determination on HepG2 human cells showed that biotransformation products obtained from the bacterial growth was not toxic. The higher removal efficiency for sildenafil citrate and the lack of toxicity by the biotransformation products obtained showed that the microbial community identified here represented a composite population that might have biotechnological relevance to

Identification and characterization of AckA-dependent protein acetylation in Neisseria gonorrhoeae.

Directory of Open Access Journals (Sweden)

Deborah M B Post

Full Text Available Neisseria gonorrhoeae, the causative agent of gonorrhea, has a number of factors known to contribute to pathogenesis; however, a full understanding of these processes and their regulation has proven to be elusive. Post-translational modifications (PTMs of bacterial proteins are now recognized as one mechanism of protein regulation. In the present study, Western blot analyses, with an anti-acetyl-lysine antibody, indicated that a large number of gonococcal proteins are post-translationally modified. Previous work has shown that Nε-lysine acetylation can occur non-enzymatically with acetyl-phosphate (AcP as the acetyl donor. In the current study, an acetate kinase mutant (1291ackA, which accumulates AcP, was generated in N. gonorrhoeae. Broth cultures of N. gonorrhoeae 1291wt and 1291ackA were grown, proteins extracted and digested, and peptides containing acetylated-lysines (K-acetyl were affinity-enriched from both strains. Mass spectrometric analyses of these samples identified a total of 2686 unique acetylation sites. Label-free relative quantitation of the K-acetyl peptides derived from the ackA and wild-type (wt strains demonstrated that 109 acetylation sites had an ackA/wt ratio>2 and p-values <0.05 in at least 2/3 of the biological replicates and were designated as "AckA-dependent". Regulated K-acetyl sites were found in ribosomal proteins, central metabolism proteins, iron acquisition and regulation proteins, pilus assembly and regulation proteins, and a two-component response regulator. Since AckA is part of a metabolic pathway, comparative growth studies of the ackA mutant and wt strains were performed. The mutant showed a growth defect under aerobic conditions, an inability to grow anaerobically, and a defect in biofilm maturation. In conclusion, the current study identified AckA-dependent acetylation sites in N. gonorrhoeae and determined that these sites are found in a diverse group of proteins. This work lays the foundation for

Citric complexes, neodymium citrate and americium citrate

International Nuclear Information System (INIS)

Bouhlassa, Saidati.

1981-06-01

The behaviour of neodymium and americium has been studied in citric aqueous medium by two methods: solvent extraction of elements at tracer scale as chelates and by potentiometry. So range of pH and concentrations of elements and citric acid never reached before have been explored: 10 -7 -1 M, 10 -10 -3 , Csub(H3 Cit) -1 M, 1 2 O; AmCit, xH 2 O; NdCit 2 Co(NH 3 ) 6 , 8H 2 O; AmCit 2 Co(NH 3 ) 6 , xH 2 O and Nd 3 (OH) 4 (Cit) 4 NH 4 (Co(NH 3 ) 6 ) 2 , 18H 2 O. Their spectroscopic and crystallographic characteristics have been listed and studied. The nephelauxetic effect has been estimated from citric complexes as well as from citrates of these elements. The structure of the complexes in solution has been discussed on the basis of analysis of hypersensitive transition in different complexes [fr

Artificial Citrate Operon Confers Mineral Phosphate Solubilization Ability to Diverse Fluorescent Pseudomonads

Science.gov (United States)

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. PMID:25259527

Alkali absorption and citrate excretion in calcium nephrolithiasis

Science.gov (United States)

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 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).

Preparation of radioactive acetyl-l-carnitine by an enzymatic exchange reaction

International Nuclear Information System (INIS)

Emaus, R.; Bieber, L.L.

1982-01-01

A rapid method for the preparation of [1- 14 C]acetyl-L-carnitine is described. The method involves exchange of [1- 14 C]acetic acid into a pool of unlabeled acetyl-L-carnitine using the enzymes acetyl-CoA synthetase and carnitine acetyltransferase. After isotopic equilibrium is attained, radioactive acetylcarnitine is separated from the other reaction components by chromatography on Dowex 1 (C1 - ) anion exchange resin. One of the procedures used to verify the product [1- 14 C]acetyl-L-carnitine can be used to synthesize (3S)-[5- 14 C]citric acid

Changes in nuclear protein acetylation in u. v. -damaged human cells

Energy Technology Data Exchange (ETDEWEB)

Ramanathan, B.; Smerdon, M.J.

1986-07-01

We have investigated the levels of nuclear protein acetylation in u.v.-irradiated human fibroblasts. We measured the levels of acetylation in total acid-soluble nuclear proteins and observed two distinct differences between the irradiated and unirradiated (control) cells. Immediately after irradiation, there is a wave of protein hyperacetylation (i.e. a total acetylation level greater than that of unirradiated cells) that lasts for 2-6 h depending on the experimental conditions. This hyperacetylation phase is then followed by a hypoacetylation phase, lasting for many hours, and the total level of acetylation does not return to that of control cells until 24-72 h after u.v. damage. Both the magnitude and duration of each phase is dependent on the dose of u.v. light used. The wave of hyperacetylation is more pronounced at low u.v. doses (i.e. less than 5 J/m2), while the wave of hypoacetylation is more pronounced at higher u.v. doses (greater than or equal to 8 J/m2). Furthermore, the duration of each phase is prolonged when cells are exposed to 2 mM hydroxyurea. Examination of the acetylation levels of the individual nuclear proteins indicated that acetylation of the core histones follows the same pattern observed for the total acid-soluble protein fractions. Furthermore, these were the only major proteins in the total acid-soluble fraction observed to undergo the early, rapid hyperacetylation immediately following u.v. damage. Acetylation of histone H1 was negligible in both damaged and control cells, while three prominent non-histone proteins were acetylated only after long labeling times (greater than 4 h) in each case, gradually becoming hyperacetylated in the u.v.-damaged cells. These results raise the possibility that a causal relationship exists between nuclear protein acetylation and nucleotide excision repair of DNA in human cells.

Calcium citrate: a new biomaterial that can enhance bone formation in situ

Directory of Open Access Journals (Sweden)

WANG Li-ming

2012-11-01

Full Text Available 【Abstract】 Objective: To investigate the effect of a new biomaterial combining calcium citrate and recombinant human bone morphogenetic protein-2 (rhBMP-2 on bone regeneration in a bone defect rabbit model. Methods: Totally 30 male New Zealand white rabbits were randomly and equally divided into calcium citrate-rhBMP-2 (CC-rhBMP-2 group and rhBMP-2 only group. Two 10 mm-long and 5 mm-deep bone defects were respec-tively created in the left and right femoral condyles of the rabbits. Subsequently 5 pellets of calcium citrate (10 mg combined with rhBMP-2 (2 mg or rhBMP-2 alone were im-planted into the bone defects and compressed with cotton swab. Bone granules were obtained at 2, 4 and 6 weeks after procedure and received histological analysis. LSD t-test and a subsequent t-test were adopted for statistical analysis. Results: Histomorphometric analysis revealed newly formed bones, and calcium citrate has been absorbed in the treatment group. The percent of newly formed bone area in femoral condyle in control group and CC-rhBMP-2 group was respectively 31.73%±1.26% vs 48.21%±2.37% at 2 weeks; 43.40%±1.65% vs 57.32%±1.47% at 4 weeks, and 51.32%±7.80% vs 66.74%±4.05% at 6 weeks (P<0.05 for all. At 2 weeks, mature cancellous bone was observed to be already formed in the treatment group. Conclusion: From this study, it can be concluded that calcium citrate combined with rhBMP-2 signifcantly en-hances bone regeneration in bone defects. This synthetic gelatin matrix stimulates formation of new bone and bone marrow in the defect areas by releasing calcium ions. Key words: Bone morphogenetic protein-2; Biocompatible materials; Calcium citrate; Gelatin

Metabolism of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine in the human neutrophil

International Nuclear Information System (INIS)

Triggiani, M.; D'Souza, D.M.; Chilton, F.H.

1991-01-01

The biosynthesis of 1-acyl-2-acetyl-sn-glycero-3-phosphocholine (1-acyl-2-acetyl-GPC) together with that of 1-alkyl-2-acetyl-GPC (platelet-activating factor) has been demonstrated in a variety of inflammatory cells and tissues. It has been hypothesized that the relative proportion of these phospholipids produced upon cell activation may be influenced by their rates of catabolism. We studied the catabolism of 1-acyl-2-acetyl-GPC in resting and activated human neutrophils and compared it to that of 1-alkyl-2-acetyl-GPC. Neutrophils rapidly catabolize both 1-alkyl-2-acetyl-GPC and 1-acyl-2-acetyl-GPC; however, the rate of catabolism of 1-acyl-2-acetyl-GPC is approximately 2-fold higher than that of 1-alkyl-2-acetyl-GPC. In addition, most of 1-acyl-2-acetyl-GPC is catabolized through a pathway different from that of 1-alkyl-2-acetyl-GPC. The main step in the catabolism of 1-acyl-2-acetyl-GPC is the removal of the long chain at the sn-1 position; the long chain residue is subsequently incorporated either into triglycerides or into phosphatidylcholine. The 1-lyso-2-acetyl-GPC formed in this reaction is then further degraded to glycerophosphocholine, choline, or phosphocholine. 1-Acyl-2-acetyl-GPC is also catabolized, to a lesser extent, through deacetylation at the sn-2 position and reacylation with a long chain fatty acid. Stimulation of neutrophils by A23187 results in a higher rate of catabolism of 1-acyl-2-acetyl-GPC by increasing both the removal of the long chain at the sn-1 position and the deacetylation-reacylation at the sn-2 position. In a broken cell preparation, the cytosolic fraction of the neutrophil was shown to contain an enzyme activity which cleaved the sn-1 position of 1-acyl-2-acetyl-GPC and 1-acyl-2-lyso-GPC but not of 1,2-diacyl-GPC

The kinetics of the acetylation of gelatinised potato starch

NARCIS (Netherlands)

de Graaf, R.A.; Broekroelofs, G.A.; Janssen, L.P.B.M.; Beenackers, A.A C M

1995-01-01

The reaction rates, in the base-catalysed acetylation of gelatinised aqueous starch (4 wt%), by vinylacetate (ViAc), were investigated in a semibatch reactor at temperatures ranging from 20 to 50 degrees C. The desired starch acetylation reaction is accompanied by an undesired parallel

Phosphorylation and Acetylation of Acyl-CoA Synthetase- I

DEFF Research Database (Denmark)

Frahm, Jennifer L; Li, Lei O; Grevengoed, Trisha J

2011-01-01

Long chain acyl-CoA synthetase 1 (ACSL1) contributes 50 to 90% of total ACSL activity in liver, adipose tissue, and heart and appears to direct the use of long chain fatty acids for energy. Although the functional importance of ACSL1 is becoming clear, little is understood about its post...... and acetylated amino acids by mass spectrometry. We then compared these results to the post-translational modifications observed in vivo in liver and brown adipose tissue after mice were fasted or exposed to a cold environment. We identified universal N-terminal acetylation, 15 acetylated lysines, and 25...

Radiolabeled porphyrin versus gallium-67 citrate for the detection of human melanoma in athymic mice

International Nuclear Information System (INIS)

Maric, N.; Chan, S. Ming; Hoffer, P.B.; Duray, P.

1987-01-01

We performed the biodistribution and imaging studies of 111 In and 67 Ga labeled tetra(4-N-methylpyridyl) porphine, (T4NMPYP), and compared it to that of 67 Ga citrate in athymic mice bearing a human melanoma xenograft. The biodistribution results of both 111 In and 67 Ga labeled T4NMPYP (3, 6, 24, and 48 hours) were similar but differed from that of 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 67 Ga citrate at 48 hours postinjection. Kidney was the only organ showing higher uptake of radiolabeled porphyrin compared to that of 67 Ga citrate. The imaging studies performed with 111 In T4NMPYP and 67 Ga citrate correspond to the biodistribution results. Osteomyelitis present in one mouse showed good localization of 111 In T4NMPYP. 15 refs., 3 figs., 5 tabs

The Caenorhabditis elegans Elongator complex regulates neuronal alpha-tubulin acetylation.

Directory of Open Access Journals (Sweden)

Jachen A Solinger

2010-01-01

Full Text Available Although acetylated alpha-tubulin is known to be a marker of stable microtubules in neurons, precise factors that regulate alpha-tubulin acetylation are, to date, largely unknown. Therefore, a genetic screen was employed in the nematode Caenorhabditis elegans that identified the Elongator complex as a possible regulator of alpha-tubulin acetylation. Detailed characterization of mutant animals revealed that the acetyltransferase activity of the Elongator is indeed required for correct acetylation of microtubules and for neuronal development. Moreover, the velocity of vesicles on microtubules was affected by mutations in Elongator. Elongator mutants also displayed defects in neurotransmitter levels. Furthermore, acetylation of alpha-tubulin was shown to act as a novel signal for the fine-tuning of microtubules dynamics by modulating alpha-tubulin turnover, which in turn affected neuronal shape. Given that mutations in the acetyltransferase subunit of the Elongator (Elp3 and in a scaffold subunit (Elp1 have previously been linked to human neurodegenerative diseases, namely Amyotrophic Lateral Sclerosis and Familial Dysautonomia respectively highlights the importance of this work and offers new insights to understand their etiology.

Synthesis of O-[{sup 11}C]acetyl CoA, O-[{sup 11}C]acetyl-L-carnitine, and L-[{sup 11}C]carnitine labelled in specific positions, applied in PET studies on rhesus monkey

Energy Technology Data Exchange (ETDEWEB)

Jacobson, Gunilla B.; Watanabe, Yasuyoshi; Valind, Sven; Kuratsune, Hirohiko; Laangstroem, Bengt

1997-07-01

The syntheses of L-carnitine, O-acetyl CoA, and O-acetyl-L-carnitine labelled with {sup 11}C at the 1- or 2-position of the acetyl group or the N-methyl position of carnitine, using the enzymes acetyl CoA synthetase and carnitine acetyltransferase, are described. With a total synthesis time of 45 min, O-[1-{sup 11}C]acetyl CoA and O-[2-{sup 11}C]acetyl CoA was obtained in 60-70% decay-corrected radiochemical yield, and O-[1-{sup 11}C]acetyl-L-carnitine and O-[2-{sup 11}C]acetyl-L-carnitine in 70-80% yield, based on [1-{sup 11}C]acetate or [2-{sup 11}C]acetate, respectively. By an N-methylation reaction with [{sup 11}C]methyl iodide, L-[methyl-{sup 11}C]carnitine was obtained within 30 min, and O-acetyl-L-[methyl-{sup 11}C]carnitine within 40 min, giving a decay-corrected radiochemical yield of 60% and 40-50%, respectively, based on [{sup 11}C]methyl iodide. Initial data of the kinetics of the different {sup 11}C-labelled L-carnitine and acetyl-L-carnitines in renal cortex of anaesthetized monkey (Macaca mulatta) are presented.

Total levels of hippocampal histone acetylation predict normal variability in mouse behavior.

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Addie May I Nesbitt

Full Text Available Genetic, pharmacological, and environmental interventions that alter total levels of histone acetylation in specific brain regions can modulate behaviors and treatment responses. Efforts have been made to identify specific genes that are affected by alterations in total histone acetylation and to propose that such gene specific modulation could explain the effects of total histone acetylation levels on behavior - the implication being that under naturalistic conditions variability in histone acetylation occurs primarily around the promoters of specific genes.Here we challenge this hypothesis by demonstrating with a novel flow cytometry based technique that normal variability in open field exploration, a hippocampus-related behavior, was associated with total levels of histone acetylation in the hippocampus but not in other brain regions.Results suggest that modulation of total levels of histone acetylation may play a role in regulating biological processes. We speculate in the discussion that endogenous regulation of total levels of histone acetylation may be a mechanism through which organisms regulate cellular plasticity. Flow cytometry provides a useful approach to measure total levels of histone acetylation at the single cell level. Relating such information to behavioral measures and treatment responses could inform drug delivery strategies to target histone deacetylase inhibitors and other chromatin modulators to places where they may be of benefit while avoiding areas where correction is not needed and could be harmful.

Genetic control of differential acetylation in diabetic rats.

Directory of Open Access Journals (Sweden)

Pamela J Kaisaki

Full Text Available Post-translational protein modifications such as acetylation have significant regulatory roles in metabolic processes, but their relationship to both variation in gene expression and DNA sequence is unclear. We address this question in the Goto-Kakizaki (GK rat inbred strain, a model of polygenic type 2 diabetes. Expression of the NAD-dependent deacetylase Sirtuin-3 is down-regulated in GK rats compared to normoglycemic Brown Norway (BN rats. We show first that a promoter SNP causes down-regulation of Sirtuin-3 expression in GK rats. We then use mass-spectrometry to identify proteome-wide differential lysine acetylation of putative Sirtuin-3 protein targets in livers of GK and BN rats. These include many proteins in pathways connected to diabetes and metabolic syndrome. We finally sequence GK and BN liver transcriptomes and find that mRNA expression of these targets does not differ significantly between GK and BN rats, in contrast to other components of the same pathways. We conclude that physiological differences between GK and BN rats are mediated by a combination of differential protein acetylation and gene transcription and that genetic variation can modulate acetylation independently of expression.

21 CFR 73.2110 - Bismuth citrate.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Bismuth citrate. 73.2110 Section 73.2110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR... paragraph (c)(1), effective April 27, 2010. For the convenience of the user, the revised text is set forth...

Plasma Membrane Na+-Coupled Citrate Transporter (SLC13A5 and Neonatal Epileptic Encephalopathy

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Yangzom D. Bhutia

2017-02-01

Full Text Available SLC13A5 is a Na+-coupled transporter for citrate that is expressed in the plasma membrane of specific cell types in the liver, testis, and brain. It is an electrogenic transporter with a Na+:citrate3− stoichiometry of 4:1. In humans, the Michaelis constant for SLC13A5 to transport citrate is ~600 μM, which is physiologically relevant given that the normal concentration of citrate in plasma is in the range of 150–200 μM. Li+ stimulates the transport function of human SLC13A5 at concentrations that are in the therapeutic range in patients on lithium therapy. Human SLC13A5 differs from rodent Slc13a5 in two important aspects: the affinity of the human transporter for citrate is ~30-fold less than that of the rodent transporter, thus making human SLC13A5 a low-affinity/high-capacity transporter and the rodent Slc13a5 a high-affinity/low-capacity transporter. In the liver, SLC13A5 is expressed exclusively in the sinusoidal membrane of the hepatocytes, where it plays a role in the uptake of circulating citrate from the sinusoidal blood for metabolic use. In the testis, the transporter is expressed only in spermatozoa, which is also only in the mid piece where mitochondria are located; the likely function of the transporter in spermatozoa is to mediate the uptake of citrate present at high levels in the seminal fluid for subsequent metabolism in the sperm mitochondria to generate biological energy, thereby supporting sperm motility. In the brain, the transporter is expressed mostly in neurons. As astrocytes secrete citrate into extracellular medium, the potential function of SLC13A5 in neurons is to mediate the uptake of circulating citrate and astrocyte-released citrate for subsequent metabolism. Slc13a5-knockout mice have been generated; these mice do not have any overt phenotype but are resistant to experimentally induced metabolic syndrome. Recently however, loss-of-function mutations in human SLC13A5 have been found to cause severe epilepsy

Application of the MIDAS approach for analysis of lysine acetylation sites.

Science.gov (United States)

Evans, Caroline A; Griffiths, John R; Unwin, Richard D; Whetton, Anthony D; Corfe, Bernard M

2013-01-01

Multiple Reaction Monitoring Initiated Detection and Sequencing (MIDAS™) is a mass spectrometry-based technique for the detection and characterization of specific post-translational modifications (Unwin et al. 4:1134-1144, 2005), for example acetylated lysine residues (Griffiths et al. 18:1423-1428, 2007). The MIDAS™ technique has application for discovery and analysis of acetylation sites. It is a hypothesis-driven approach that requires a priori knowledge of the primary sequence of the target protein and a proteolytic digest of this protein. MIDAS essentially performs a targeted search for the presence of modified, for example acetylated, peptides. The detection is based on the combination of the predicted molecular weight (measured as mass-charge ratio) of the acetylated proteolytic peptide and a diagnostic fragment (product ion of m/z 126.1), which is generated by specific fragmentation of acetylated peptides during collision induced dissociation performed in tandem mass spectrometry (MS) analysis. Sequence information is subsequently obtained which enables acetylation site assignment. The technique of MIDAS was later trademarked by ABSciex for targeted protein analysis where an MRM scan is combined with full MS/MS product ion scan to enable sequence confirmation.

Differentiation of malignant and degenerative benign bone disease using 99mTc-citrate scintigraphy

International Nuclear Information System (INIS)

Guo Rui; Jin Jianhua; Li Sijin; Li Xianfeng; Zhang Xiaojuan; Ren Yuan

2008-01-01

Objective: To differentiate malignant and degenerative benign bone disease using 99m Tc- citrate scintigraphy. Methods: Thirty-nine patients (92 lesions) with confirmed malignant bone disease or degenerative benign bone disease were studied, for which the results of 99m Te-methylene diphosphonate( 99m Tc- MDP) scintigraphy were positive. 99m Tc-citrate scintigraphy was performed within a time interval of 2-7 days after 99m Tc-MDP scintigraphy. Visual analysis and semiquantitative analysis were applied. Each lesion was scored as malignant or benign, which was independently verified, using conventional techniques (histopathology, X-ray, CT, MRI and clinical follow up). Results: In visual analysis of 99m Tc-citrate imaging, most malignant lesions (35/48, 72.92%) clearly showed high radioactivity accumulation, while most benign lesions (39/44, 88.64%) had not obviously visible uptake of 99m Tc-citrate. In semiquantitative analysis of 99m Tc- citrate image, malignant lesions demonstrated a higher lesion-to-background radioisotope uptake ratio (RUR) than that of benign degenerative lesions (1.47 ± 0.42 vs. 1.09 ± 0.38, t=2.887, P 99m Tc-MDP in the two groups is of the same (1.96 ± 0.25 vs. 1.87 ± 0.21, t=1.178, P>0.20). Conclusion: 99m Tc- citrate scintigraphy is a promising method to differentiate malignant from benign degenerative lesions seen as areas of increased activity on 99m Tc-MDP bone scintigraphy. (authors)

Metformin-letrozole in comparison with Metformin-clomiphene citrate in clomiphene-resistance PCOS patients undergoing IUI

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Mohammad Hossein Fallahzadeh

2011-01-01

Full Text Available Background: Polycystic ovary syndrome (PCOS is associated with approximately 75% of women who suffer from infertility due to anovulation. Additionally, around 20– 25% of anovulatory women with PCOS do not respond at all to clomiphene citrate and are considered to be “clomiphene– resistant”. Aromatase inhibitors have been suggested as an alternative treatment to clomiphene as the discrepancy between ovulation and pregnancy rates with clomiphene citrate has been attributed to its anti-estrogenic action and estrogen receptor depletion. Objective: The aim of this study is to compare results of Metformin-letrozole with Metformin-clomiphene citrate in clomiphene resistance PCOS patients undergoing IUI.Materials and Methods: In this single blind randomized trial, ovarian cycles were studied in 100 clomiphene- resistant patients with PCOS. The inclusion criteria were patients who received 150mg clomiphene citrate daily for 3 cycles and failed to become pregnant. The patients were matched for their age, body mass index (BMI, and infertility period. They were randomly allocated to a metformin-letrozole group (n=50 and a metformin-clomiphene citrate group (n=50. Chemical and clinical pregnancies were assessed after IUI. Abortion rates were determined in both groups. Results: Regarding pregnancy rate, there was no significant difference between the two groups. One miscarriage (2% occurred in the metformin-clomiphene citrate group, whereas none was seen in the metformin-letrozole group. Conclusion: There is no significant difference in pregnancy rate between clomiphene citrate and letrozole groups although it has been 2% in the former and 5% in the latter.

Structural insights into the elevator-like mechanism of the sodium/citrate symporter CitS.

Science.gov (United States)

Kim, Ji Won; Kim, Subin; Kim, Songwon; Lee, Haerim; Lee, Jie-Oh; Jin, Mi Sun

2017-05-31

The sodium-dependent citrate transporter of Klebsiella pneumoniae (KpCitS) belongs to the 2-hydroxycarboxylate transporter (2-HCT) family and allows the cell to use citrate as sole carbon and energy source in anaerobic conditions. Here we present crystal structures of KpCitS in citrate-bound outward-facing, citrate-bound asymmetric, and citrate-free inward-facing state. The structures reveal that the KpCitS dimerization domain remains stationary throughout the transport cycle due to a hydrogen bond network as well as extensive hydrophobic interactions. In contrast, its transport domain undergoes a ~35° rigid-body rotation and a ~17 Å translocation perpendicular to the membrane to expose the substrate-binding site alternately to either side of the membrane. Furthermore, homology models of two other 2-HCT proteins based on the KpCitS structure offer structural insights into their differences in substrate specificity at a molecular level. On the basis of our results and previous biochemical data, we propose that the activity of the 2-HCT CitS involves an elevator-like movement in which the transport domain itself traverses the lipid bilayer, carrying the substrate into the cell in a sodium-dependent manner.

Influence of temperature on flavour compound production from citrate by Lactobacillus rhamnosus ATCC 7469.

Science.gov (United States)

De Figueroa, R M; Oliver, G; Benito de Cárdenas, I L

2001-03-01

The citrate utilization by Lactobacillus rhamnosus ATCC 7469 was found to be temperature-dependent. The maximum citrate utilization and incorporation of [1,5-14C]citrate rate were observed at 37 degreesC. At this temperature, maximum citrate lyase activity and specific diacetyl and acetoin production (Y(DA%)) were observed. The high levels of alpha-acetolactate synthase and low levels of diacetyl reductase, acetoin reductase and L-lactate dehydrogenase found at 37 degreesC led to an accumulation of diacetyl and acetoin. Optimum lactic acid production was observed at 45 degreesC, according to the high lactate dehydrogenase activity. The NADH oxidase activity increased with increasing culture temperature from 22 degreesC to 37 degreesC. Thus there are greater quantities of pyruvate available for the production of alpha-acetolactate, diacetyl and aceotin, and less diacetyl and acetoin are reduced.

Antitumor effect of free rhodium (II) citrate and rhodium (II) citrate-loaded maghemite nanoparticles on mice bearing breast cancer: a systemic toxicity assay.

Science.gov (United States)

Peixoto, Raphael Cândido Apolinário; Miranda-Vilela, Ana Luisa; de Souza Filho, José; Carneiro, Marcella Lemos' Brettas; Oliveira, Ricardo G S; da Silva, Matheus Oliveira; de Souza, Aparecido R; Báo, Sônia Nair

2015-05-01

Breast cancer is one of the most prevalent cancer types among women. The use of magnetic fluids for specific delivery of drugs represents an attractive platform for chemotherapy. In our previous studies, it was demonstrated that maghemite nanoparticles coated with rhodium (II) citrate (Magh-Rh2Cit) induced in vitro cytotoxicity and in vivo antitumor activity, followed by intratumoral administration in breast carcinoma cells. In this study, our aim was to follow intravenous treatment to evaluate the systemic antitumor activity and toxicity induced by these formulations in Balb/c mice bearing orthotopic 4T1 breast carcinoma. Female Balb/c mice were evaluated with regard to toxicity of intravenous treatments through analyses of hemogram, serum levels of alanine aminotransferase, iron, and creatinine and liver, kidney, and lung histology. The antitumor activity of rhodium (II) citrate (Rh2Cit), Magh-Rh2Cit, and maghemite nanoparticles coated with citrate (Magh-Cit), used as control, was evaluated by tumor volume reduction, histology, and morphometric analysis. Magh-Rh2Cit and Magh-Cit promoted a significant decrease in tumor area, and no experimental groups presented hematotoxic effects or increased levels of serum ALT and creatinine. This observation was corroborated by the histopathological examination of the liver and kidney of mice. Furthermore, the presence of nanoparticles was verified in lung tissue with no morphological changes, supporting the idea that our nanoformulations did not induce toxicity effects. No studies about the systemic action of rhodium (II) citrate-loaded maghemite nanoparticles have been carried out, making this report a suitable starting point for exploring the therapeutic potential of these compounds in treating breast cancer.

Histone acetylation regulates the time of replication origin firing.

Science.gov (United States)

Vogelauer, Maria; Rubbi, Liudmilla; Lucas, Isabelle; Brewer, Bonita J; Grunstein, Michael

2002-11-01

The temporal firing of replication origins throughout S phase in yeast depends on unknown determinants within the adjacent chromosomal environment. We demonstrate here that the state of histone acetylation of surrounding chromatin is an important regulator of temporal firing. Deletion of RPD3 histone deacetylase causes earlier origin firing and concurrent binding of the replication factor Cdc45p to origins. In addition, increased acetylation of histones in the vicinity of the late origin ARS1412 by recruitment of the histone acetyltransferase Gcn5p causes ARS1412 alone to fire earlier. These data indicate that histone acetylation is a direct determinant of the timing of origin firing.

Efficient acetylation of primary amines and amino acids in ...

Indian Academy of Sciences (India)

This effort represents the first efficient use of this most reactive but cheap acetylating agent to acetylate amines in excellent yields in aqueous medium. This is a potentially useful green chemical transformation where reaction takes place in environment-friendly brine solution leading to easy work-up and isolation of the ...

Aspirin-Mediated Acetylation Protects Against Multiple Neurodegenerative Pathologies by Impeding Protein Aggregation.

Science.gov (United States)

Ayyadevara, Srinivas; Balasubramaniam, Meenakshisundaram; Kakraba, Samuel; Alla, Ramani; Mehta, Jawahar L; Shmookler Reis, Robert J

2017-12-10

Many progressive neurological disorders, including Alzheimer's disease (AD), Huntington's disease, and Parkinson's disease (PD), are characterized by accumulation of insoluble protein aggregates. In prospective trials, the cyclooxygenase inhibitor aspirin (acetylsalicylic acid) reduced the risk of AD and PD, as well as cardiovascular events and many late-onset cancers. Considering the role played by protein hyperphosphorylation in aggregation and neurodegenerative diseases, and aspirin's known ability to donate acetyl groups, we asked whether aspirin might reduce both phosphorylation and aggregation by acetylating protein targets. Aspirin was substantially more effective than salicylate in reducing or delaying aggregation in human neuroblastoma cells grown in vitro, and in Caenorhabditis elegans models of human neurodegenerative diseases in vivo. Aspirin acetylates many proteins, while reducing phosphorylation, suggesting that acetylation may oppose phosphorylation. Surprisingly, acetylated proteins were largely excluded from compact aggregates. Molecular-dynamic simulations indicate that acetylation of amyloid peptide energetically disfavors its association into dimers and octamers, and oligomers that do form are less compact and stable than those comprising unacetylated peptides. Hyperphosphorylation predisposes certain proteins to aggregate (e.g., tau, α-synuclein, and transactive response DNA-binding protein 43 [TDP-43]), and it is a critical pathogenic marker in both cardiovascular and neurodegenerative diseases. We present novel evidence that acetylated proteins are underrepresented in protein aggregates, and that aggregation varies inversely with acetylation propensity after diverse genetic and pharmacologic interventions. These results are consistent with the hypothesis that aspirin inhibits protein aggregation and the ensuing toxicity of aggregates through its acetyl-donating activity. This mechanism may contribute to the neuro-protective, cardio

Human METTL12 is a mitochondrial methyltransferase that modifies citrate synthase.

Science.gov (United States)

Rhein, Virginie F; Carroll, Joe; Ding, Shujing; Fearnley, Ian M; Walker, John E

2017-06-01

The protein methylome in mammalian mitochondria has been little studied until recently. Here, we describe that lysine-368 of human citrate synthase is methylated and that the modifying enzyme, localized in the mitochondrial matrix, is methyltransferase-like protein 12 (METTL12), a member of the family of 7β-strand methyltransferases. Lysine-368 is near the active site of citrate synthase, but removal of methylation has no effect on its activity. In mitochondria, it is possible that some or all of the enzymes of the citric acid cycle, including citrate synthase, are organized in metabolons to facilitate the channelling of substrates between participating enzymes. Thus, possible roles for the methylation of Lys-368 are in controlling substrate channelling itself, or in influencing protein-protein interactions in the metabolon. © 2017 The Authors FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.

Citrate-coated silver nanoparticles interactions with effluent organic matter: influence of capping agent and solution conditions

KAUST Repository

Gutierrez, Leonardo

2015-07-31

Fate and transport studies of silver nanoparticles (AgNPs) discharged from urban wastewaters containing effluent organic matter (EfOM) into natural waters represent a key knowledge gap. In this study, EfOM interfacial interactions with AgNPs and their aggregation kinetics were investigated by atomic force microscopy (AFM) and time-resolved dynamic light scattering (TR-DLS), respectively. Two well-characterized EfOM isolates, i.e., wastewater humic (WW humic) and wastewater colloids (WW colloids, a complex mixture of polysaccharides-proteins-lipids), and a River humic isolate of different characteristics were selected. Citrate-coated AgNPs were selected as representative capped-AgNPs. Citrate-coated AgNPs showed a considerable stability in Na+ solutions. However, Ca2+ ions induced aggregation by cation bridging between carboxyl groups on citrate. Although the presence of River humic increased the stability of citrate-coated AgNPs in Na+ solutions due to electrosteric effects, they aggregated in WW humic-containing solutions, indicating the importance of humics characteristics during interactions. Ca2+ ions increased citrate-coated AgNPs aggregation rates in both humic solutions, suggesting cation bridging between carboxyl groups on their structures as a dominant interacting mechanism. Aggregation of citrate-coated AgNPs in WW colloids solutions was significantly faster than those in both humic solutions. Control experiments in urea solution indicated hydrogen bonding as the main interacting mechanism. During AFM experiments, citrate-coated AgNPs showed higher adhesion to WW humic than to River humic, evidencing a consistency between TR-DLS and AFM results. Ca2+ ions increased citrate-coated AgNPs adhesion to both humic isolates. Interestingly, strong WW colloids interactions with citrate caused AFM probe contamination (nanoparticles adsorption) even at low Na+ concentrations, indicating the impact of hydrogen bonding on adhesion. These results suggest the importance

Tritium distribution ratios between the 30 % tributyl phosphate(TBP)-normal dodecane(nDD) organic phase and uranyl nitrate-nitric acid aqueous phase

International Nuclear Information System (INIS)

Fujine, Sachio; Uchiyama, Gunzou; Sugikawa, Susumu; Maeda, Mitsuru; Tsujino, Takeshi.

1989-10-01

Tritium distribution ratios between the organic and aqueous phases were measured for the system of 30 % tributyl phosphate(TBP)-normal dodecane(nDD)/uranyl nitrate-nitric acid water. It was confirmed that tritium is extracted by TBP into the organic phase in both chemical forms of tritiated water (HTO) and tritiated nitric acid (TNO 3 ). The value of tritium distribution ratio ranged from 0.002 to 0.005 for the conditions of 0-6 mol/L nitric acid, 0.5-800 mCi/L tritium in aqueous phase, and 0-125 g-U/L uranium in organic phase. Isotopic distribution coefficient of tritium between the organic and aqueous phases was observed to be about 0.95. (author)

Synthetic biology for engineering acetyl coenzyme a metabolism in yeast

DEFF Research Database (Denmark)

Nielsen, Jens

2014-01-01

The yeast Saccharomyces cerevisiae is a widely used cell factory for the production of fuels, chemicals, and pharmaceuticals. The use of this cell factory for cost-efficient production of novel fuels and chemicals requires high yields and low by-product production. Many industrially interesting...... chemicals are biosynthesized from acetyl coenzyme A (acetyl-CoA), which serves as a central precursor metabolite in yeast. To ensure high yields in production of these chemicals, it is necessary to engineer the central carbon metabolism so that ethanol production is minimized (or eliminated) and acetyl...

Corrosion behavior of Ti and TI6Al4V in citrate buffers containing fluoride ions

Directory of Open Access Journals (Sweden)

Anelise Marlene Schmidt

2010-03-01

Full Text Available The effect of fluoride ions concentration on the electrochemical behavior of Ti grade 2 and Ti6Al4V in citrate buffers was studied. Open circuit potential (OCP measurements and voltammetric studies of the samples in the fluoride containing citrate buffers revealed a dissolution process when the pH falls below 5.0 and the NaF content is higher than 0.01 M. However, in citrate pH 7.6 the materials showed a passive behavior even in 0.1 M NaF. Some micrographs of Ti grade 2 obtained after longer immersion times in citrate pH 5.0 with 0.01 M NaF showed a surface attack. EIS (Electrochemical Impedance Sprectroscopy data obtained at the OCP revealed that the film resistance decreases when the immersion time is increased in pH 5.0 containing 0.1 M NaF. In the citrate pH 7.6 the EIS data indicated a two-layer model of an oxide film consisting of a more compact inner layer and a porous outer layer. On the other hand, the EIS results in citrate pH 4.0 change significantly when the fluoride ions concentration increases from 0.01 to 0.05 M. The electrochemical data revealed that the corrosion behavior of Ti grade 2 and Ti6Al4V in the citrate buffers depends on the pH, the fluoride content and the exposure time.

Sildenafil citrate (Viagra) impairs fertilization and early embryo development in mice.

Science.gov (United States)

Glenn, David R J; McClure, Neil; Cosby, S Louise; Stevenson, Michael; Lewis, Sheena E M

2009-03-01

To determine the effects of sildenafil citrate, a cyclic monophosphate-specific type 5 phosphodiesterase inhibitor known to affect sperm function, on fertilization and early embryo cleavage. This acute mammal study included male and female mice assigned randomly, the females sacrificed after mating and their oocytes/embryos evaluated at four time periods after treatment. Academic research environment. Male and female CBAB(6) mice. Female mice were injected intraperitoneally with 5 IU gonadotropin (hCG) to stimulate follicular growth and induce ovulation. They were each caged with a male that had been gavaged with sildenafil citrate (0.06 mg/0.05 mL) and allowed to mate. After 12, 36, 60, and 84 h, females were killed, their oviducts were dissected out, and retrieved embryos were assessed for blastomere number and quality. Fertilization rates and numbers of embryos were evaluated after treatment. Fertilization rates (day 1) were markedly reduced (-33%) in matings where the male had taken sildenafil citrate. Over days 2-4, the numbers of embryos developing in the treated group were significantly fewer than in the control group. There was also a trend for impaired cleavage rates within those embryos, although this did not reach significance. The impairments to fertility caused by sildenafil citrate have important implications for infertility centers and for couples who are using this drug precoitally while attempting to conceive.

Mechanism of the lysosomal membrane enzyme acetyl coenzyme A: alpha-glucosaminide N-acetyltransferase

International Nuclear Information System (INIS)

Bame, K.J.

1986-01-01

Acetyl-CoA:α-glucosaminide N-acetyltransferase is a lysosomal membrane enzyme, deficient in the genetic disease Sanfilippo C syndrome. The enzyme catalyzes the transfer of an acetyl group from cytoplasmic acetyl-CoA to terminal α-glucosamine residues of heparan sulfate within the organelle. The reaction mechanism was examined using high purified lysosomal membranes from rat liver and human fibroblasts. The N-acetyltransferase reaction is optimal above pH 5.5 and a 2-3 fold stimulation of activity is observed in the presence of 0.1% taurodeoxycholate. Double reciprocal analysis and product inhibition studies indicate that the enzyme works by a Di-Iso Ping Pong Bi Bi mechanism. The binding of acetyl-CoA to the enzyme is measured by exchange label from [ 3 H]CoA to acetyl-CoA, and is optimal at pH's above 7.0. The acetyl-enzyme intermediate is formed by incubating membranes with [ 3 H]acetyl-CoA. The acetyl group can be transferred to glucosamine, forming [ 3 H]N-acetylglucosamine; the transfer is optimal between pH 4 and 5. Lysosomal membranes from Sanfilippo C fibroblasts confirm that these half reactions carried out by the N-acetyltransferase. The enzyme is inactivated by N-bromosuccinimide and diethylpyrocarbonate, indicating that a histidine is involved in the reaction. These results suggest that the histidine residue is at the active site of the enzyme. The properties of the N-acetyltransferase in the membrane, the characterization of the enzyme kinetics, the chemistry of a histidine mediated acetylation and the pH difference across the lysosomal membrane all support a transmembrane acetylation mechanism

Renal Localization of 67Ga Citrate in Noninfectious Nephritis

International Nuclear Information System (INIS)

Lee, Kang Wook; Jeong, Min Soo; Rhee, Sunn Kgoo; Kim, Sam Yong; Shin, Young Tai; Ro, Heung Kyu

1992-01-01

67 Ga citrate scan has been requested for detection or follow-up of inflammatory or neoplastic disease. Visualization of 67 Ga citrate in the kidneys at 48 and 72 hr post injection is usually interpreted as evidence of renal pathology. But precise mechanisms of abnormal 67 Ga uptake in kidneys were unknown. We undertook a study to determine the clinical value of 67 Ga citrate imaging of the kidneys in 68 patients with primary or secondary nephropathy confirmed by renal biopsy and 66 control patients without renal disease. Renal uptake in 48 to 72 hr images was graded as follows: Grade 0=background activity;1=faint uptake greater than background; 2=definite uptake, but less than lumbar vertebrae;3 same uptake as lumbar vertebrae, but less than liver; 4=same or higher uptake than liver. The results were as follows. 1) 42 of 68(62%) patients with noninfectious nephritis showed grade 2 or higher 67 Ga renal uptake but only 10 percent of control patients showed similar uptake. 2) In 14 patients with systemic lupus erythematosus, 8 of 9 (89%) patients with lupus nephritis exhibited marked renal uptake. 3) 36 of 41 patients (88%) with combined nephrotic syndrome showed Grade 2 or higher renal uptake. 4) Renal 67 Ga uptake was correlated with clinical severity of nephrotic syndrome determined by serum albumin level, 24 hr urine protein excretion and serum lipid levels. 5) After complete remission of nephrotic syndrome, renal uptake in all 8 patients who were initially Grade 3 or 4, decreased to Grade 1 or 0. In conclusion, we think that the mechanism of renal 67 Ga uptake in nephrotic syndrome might be related to the pathogenesis of nephrotic syndrome. In systemic lupus erythematosus, 67 Ga citrate scan is useful in predicting renal involvement.

Biological Significance of the Suppression of Oxidative Phosphorylation in Induced Pluripotent Stem Cells

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Cheng Zhang

2017-11-01

Full Text Available We discovered that induced pluripotent stem cell (iPSC clones generated from aged tissue donors (A-iPSCs fail to suppress oxidative phosphorylation. Compared to embryonic stem cells (ESCs and iPSCs generated from young donors (Y-iPSCs, A-iPSCs show poor expression of the pluripotent stem cell-specific glucose transporter 3 (GLUT3 and impaired glucose uptake, making them unable to support the high glucose demands of glycolysis. Persistent oxidative phosphorylation in A-iPSCs generates higher levels of reactive oxygen species (ROS, which leads to excessive elevation of glutathione (a ROS-scavenging metabolite and a blunted DNA damage response. These phenotypes were recapitulated in Y-iPSCs by inhibiting pyruvate dehydrogenase kinase (PDK or supplying citrate to activate oxidative phosphorylation. In addition, oxidative phosphorylation in A-iPSC clones depletes citrate, a nuclear source of acetyl group donors for histone acetylation; this consequently alters histone acetylation status. Expression of GLUT3 in A-iPSCs recovers the metabolic defect, DNA damage response, and histone acetylation status.

The structure and binding mode of citrate in the stabilization of gold nanoparticles

KAUST Repository

Al-Johani, Hind; Abou-Hamad, Edy; Jedidi, Abdesslem; Widdifield, Cory M.; Viger-Gravel, Jasmine; Sangaru, Shiv; Gajan, David; Anjum, Dalaver H.; Ould-Chikh, Samy; Hedhili, Mohamed N.; Gurinov, Andrei; Kelly, Michael J.; El Eter, Mohamad; Cavallo, Luigi; Basset, Jean-Marie; Basset, Jean-Marie

2017-01-01

Elucidating the binding mode of carboxylate-containing ligands to gold nanoparticles (AuNPs) is crucial to understand their stabilizing role. A detailed picture of the three-dimensional structure and coordination modes of citrate, acetate, succinate and glutarate to AuNPs is obtained by 13C and 23Na solid-state NMR in combination with computational modelling and electron microscopy. The binding between the carboxylates and the AuNP surface is found to occur in three different modes. These three modes are simultaneously present at low citrate to gold ratios, while a monocarboxylate monodentate (1κO1) mode is favoured at high citrate:gold ratios. The surface AuNP atoms are found to be predominantly in the zero oxidation state after citrate coordination, although trace amounts of Auδ+ are observed. 23Na NMR experiments show that Na+ ions are present near the gold surface, indicating that carboxylate binding occurs as a 2e− L-type interaction for each oxygen atom involved. This approach has broad potential to probe the binding of a variety of ligands to metal nanoparticles.

The structure and binding mode of citrate in the stabilization of gold nanoparticles

KAUST Repository

Al-Johani, Hind

2017-03-27

Elucidating the binding mode of carboxylate-containing ligands to gold nanoparticles (AuNPs) is crucial to understand their stabilizing role. A detailed picture of the three-dimensional structure and coordination modes of citrate, acetate, succinate and glutarate to AuNPs is obtained by 13C and 23Na solid-state NMR in combination with computational modelling and electron microscopy. The binding between the carboxylates and the AuNP surface is found to occur in three different modes. These three modes are simultaneously present at low citrate to gold ratios, while a monocarboxylate monodentate (1κO1) mode is favoured at high citrate:gold ratios. The surface AuNP atoms are found to be predominantly in the zero oxidation state after citrate coordination, although trace amounts of Auδ+ are observed. 23Na NMR experiments show that Na+ ions are present near the gold surface, indicating that carboxylate binding occurs as a 2e− L-type interaction for each oxygen atom involved. This approach has broad potential to probe the binding of a variety of ligands to metal nanoparticles.

Acetylation-Mediated Proteasomal Degradation of Core Histones during DNA Repair and Spermatogenesis

Science.gov (United States)

Qian, Min-Xian; Pang, Ye; Liu, Cui Hua; Haratake, Kousuke; Du, Bo-Yu; Ji, Dan-Yang; Wang, Guang-Fei; Zhu, Qian-Qian; Song, Wei; Yu, Yadong; Zhang, Xiao-Xu; Huang, Hai-Tao; Miao, Shiying; Chen, Lian-Bin; Zhang, Zi-Hui; Liang, Ya-Nan; Liu, Shan; Cha, Hwangho; Yang, Dong; Zhai, Yonggong; Komatsu, Takuo; Tsuruta, Fuminori; Li, Haitao; Cao, Cheng; Li, Wei; Li, Guo-Hong; Cheng, Yifan; Chiba, Tomoki; Wang, Linfang; Goldberg, Alfred L.; Shen, Yan; Qiu, Xiao-Bo

2013-01-01

SUMMARY Histone acetylation plays critical roles in chromatin remodeling, DNA repair, and epigenetic regulation of gene expression, but the underlying mechanisms are unclear. Proteasomes usually catalyze ATP- and polyubiquitin-dependent proteolysis. Here we show that the proteasomes containing the activator PA200 catalyze the polyubiquitin-independent degradation of histones. Most proteasomes in mammalian testes (“spermatoproteasomes”) contain a spermatid/sperm-specific α-subunit α4s/PSMA8 and/or the catalytic β-subunits of immunoproteasomes in addition to PA200. Deletion of PA200 in mice abolishes acetylation-dependent degradation of somatic core histones during DNA double-strand breaks, and delays core histone disappearance in elongated spermatids. Purified PA200 greatly promotes ATP-independent proteasomal degradation of the acetylated core histones, but not polyubiquitinated proteins. Furthermore, acetylation on histones is required for their binding to the bromodomain-like regions in PA200 and its yeast ortholog, Blm10. Thus, PA200/Blm10 specifically targets the core histones for acetylation-mediated degradation by proteasomes, providing mechanisms by which acetylation regulates histone degradation, DNA repair, and spermatogenesis. PMID:23706739

Citrate effects on amorphous calcium carbonate (ACC) structure, stability, and crystallization

DEFF Research Database (Denmark)

Tobler, Dominique Jeanette; Rodriguez Blanco, Juan Diego; Dideriksen, Knud

2015-01-01

Understanding the role of citrate in the crystallization kinetics of amorphous calcium carbonate (ACC) is essential to explain the formation mechanisms, stabilities, surface properties, and morphologies of CaCO3 biominerals. It also contributes to deeper insight into fluid-mineral inte......Understanding the role of citrate in the crystallization kinetics of amorphous calcium carbonate (ACC) is essential to explain the formation mechanisms, stabilities, surface properties, and morphologies of CaCO3 biominerals. It also contributes to deeper insight into fluid...

NEW EMBO MEMBER'S REVIEW: Acetylation: a regulatory modification to rival phosphorylation?

OpenAIRE

Kouzarides, Tony

2000-01-01

The fact that histones are modified by acetylation has been known for almost 30 years. The recent identification of enzymes that regulate histone acetylation has revealed a broader use of this modification than was suspected previously. Acetylases are now known to modify a variety of proteins, including transcription factors, nuclear import factors and α–tubulin. Acetylation regulates many diverse functions, including DNA recognition, protein–protein interaction and protein stability. There i...

A study of 153Sm-citrate-hydroxyapatite synovectomy in knee synovitis with rheumatoid arthritis

International Nuclear Information System (INIS)

Fan Yanggang; Li Guohua; Yao Guozhong; Zhang Qingcheng; Li Guangming

2006-01-01

Objective: To investigate the efficacy and safety of 153 Sm-citrate-hydroxyapatite (HA) synovectomy in knee synovitis with rheumatoid arthritis (RA). Methods: In 43 RA patients ineffective to routine anti-rheumatic drugs (DMMARDs) therapy, radiation synovectomy was performed by 153 Sm-citrate-HA in 67 joints and its efficacy and safety were evaluated. Results: Radioactivity was evenly distributed as observed by gamma camera after injection. In 8 cases leakage of radioactivity was detected after 24 h, and accounted to 153 Sm-citrate-HA synovectomy is effective after short-term and medium-term follow-up and it is a safe procedure. (authors)

Mechanism of action of clostridial glycine reductase: Isolation and characterization of a covalent acetyl enzyme intermediate

International Nuclear Information System (INIS)

Arkowitz, R.A.; Abeles, R.H.

1991-01-01

Clostridial glycine reductase consists of proteins A, B, and C and catalyzes the reaction glycine + P i + 2e - → acetyl phosphate + NH 4 + . Evidence was previously obtained that is consistent with the involvement of an acyl enzyme intermediate in this reaction. The authors now demonstrate that protein C catalyzes exchange of [ 32 P]P i into acetyl phosphate, providing additional support for an acetyl enzyme intermediate on protein C. Furthermore, they have isolated acetyl protein C and shown that it is qualitatively, catalytically competent. Acetyl protein C can be obtained through the forward reaction from protein C and Se-(carboxymethyl)selenocysteine-protein A, which is generated by the reaction of glycine with proteins A and B. Acetyl protein C can also be generated through the reverse reaction by the addition of acetyl phosphate to protein C. Both procedures lead to the same acetyl enzyme. The acetyl enzyme reacts with P i to give acetyl phosphate. When [ 14 C]acetyl protein C is denaturated with TCA and redissolved with urea, radioactivity remained associated with the protein. Treatment with KBH 4 removes all the radioactivity associated with protein C, resulting in the formation of [ 14 C]ethanol. They conclude that a thiol group on protein C is acetylated. Proteins A and C together catalyze the exchange of tritium atoms from [ 3 H]H 2 O into acetyl phosphate. This exchange reaction supports the proposal that an enol of the acetyl enzyme is an intermediate in the reaction sequence

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

Science.gov (United States)

2012-08-08

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain... citric acid and certain citrate salts from the People's Republic of China.\\1\\ On May 31, 2012, we... order includes all grades and granulation sizes of citric acid, sodium citrate, and potassium citrate in...

In vivo labelling of acetyl-aspartyl peptides in mouse brain from intracranially and intracranially and intraperitoneally administered acetyl-L-[U-14C]aspartate

International Nuclear Information System (INIS)

Sinichkin, A.; Sterri, S.; Edminson, P.D.; Reichelt, K.L.; Kvamme, E.

1977-01-01

Following intracranial and intraperitoneal injection of acetyl-L-[U- 14 C]aspartate into mice about 5% and 0.7% of the radioactivity, respectively, was recovered from the brain after 30 min. On chromatographic separation of the cationic and anionic compounds on a Dowex 50 column, the former fraction contained about 60% of the radioactivity, predominantly as labelled asparate and glutamate. The anionic compounds, containing 20% of the labelled compounds, were fractionated in several chromatographic systems and resolved into a great variety of labelled peptidic compounds of which five acetyl-[U 14 ]aspartyl peptides, containing two to four amino acids, were purified. One of these, acetyl-aspartyl glutamine, has not previously been found in brain. (author)

Comparative Analysis of Proteome-Wide Lysine Acetylation in Juvenile and Adult Schistosoma japonicum

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Qing Li

2017-11-01

Full Text Available Schistosomiasis is a devastating parasitic disease caused by tremotodes of the genus Schistosoma. Eggs produced by sexually mature schistosomes are the causative agents of for pathogenesis and transmission. Elucidating the molecular mechanism of schistosome development and sexual maturation would facilitate the prevention and control of schistosomiasis. Acetylation of lysine is a dynamic and reversible post-translational modification playing keys role in many biological processes including development in both eukaryotes and prokaryotes. To investigate the impacts of lysine acetylation on Schistosoma japonicum (S. japonicum development and sexual maturation, we used immunoaffinity-based acetyllysine peptide enrichment combined with mass spectrometry (MS, to perform the first comparative analysis of proteome-wide lysine acetylation in both female and male, juvenile (18 days post infection, 18 dpi and adult (28 dpi schistosome samples. In total, we identified 874 unique acetylated sites in 494 acetylated proteins. The four samples shared 47 acetylated sites and 46 proteins. More acetylated sites and proteins shared by both females and males were identified in 28 dpi adults (189 and 143, respectively than in 18 dpi schistosomula (76 and 59, respectively. More stage-unique acetylated sites and proteins were also identified in 28 dpi adults (494 and 210, respectively than in 18 dpi schistosomula (73 and 44, respectively. Functional annotation showed that in different developmental stages and genders, a number of proteins involving in muscle movement, glycometabolism, lipid metabolism, energy metabolism, environmental stress resistance, antioxidation, etc., displayed distinct acetylation profiles, which was in accordance with the changes of their biological functions during schistosome development, suggesting that lysine acetylation modification exerted important regulatory roles in schistosome development. Taken together, our data provided the first

Acetyl Groups in Typha capensis: Fate of Acetates during Organosolv and Ionosolv Pulping

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Idi Guga Audu

2018-06-01

Full Text Available During biomass fractionation, any native acetylation of lignin and heteropolysaccharide may affect the process and the resulting lignin structure. In this study, Typha capensis (TC and its lignin isolated by milling (MWL, ionosolv (ILL and organosolv (EOL methods were investigated for acetyl group content using FT-Raman, 1H NMR, 2D-NMR, back-titration, and Zemplén transesterification analytical methods. The study revealed that TC is a highly acetylated grass; extractive free TC (TCextr and TC MWL exhibited similar values of acetyl content: 6 wt % and 8 wt % by Zemplén transesterification, respectively, and 11 wt % by back-titration. In contrast, lignin extracted from organosolv and [EMIm][OAc] pulping lost 80% of the original acetyl groups. With a high acetyl content in the natural state, TC could be an interesting raw material in biorefinery in which acetic acid could become an important by-product.

Citrate, malate and alkali content in commonly consumed diet sodas: implications for nephrolithiasis treatment.

Science.gov (United States)

Eisner, Brian H; Asplin, John R; Goldfarb, David S; Ahmad, Ardalanejaz; Stoller, Marshall L

2010-06-01

Citrate is a known inhibitor of calcium stone formation. Dietary citrate and alkali intake may have an effect on citraturia. Increasing alkali intake also increases urine pH, which can help prevent uric acid stones. We determined citrate, malate and total alkali concentrations in commonly consumed diet sodas to help direct dietary recommendations in patients with hypocitraturic calcium or uric acid nephrolithiasis. Citrate and malate were measured in a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis and in 15 diet sodas. Anions were measured by ion chromatography. The pH of each beverage was measured to allow calculation of the unprotonated anion concentration using the known pK of citric and malic acid. Total alkali equivalents were calculated for each beverage. Statistical analysis was done using Pearson's correlation coefficient. Several sodas contained an amount of citrate equal to or greater than that of alkali and total alkali as a lemonade beverage commonly used to treat hypocitraturic calcium nephrolithiasis (6.30 mEq/l citrate as alkali and 6.30 as total alkali). These sodas were Diet Sunkist Orange, Diet 7Up, Sprite Zero, Diet Canada Dry Ginger Ale, Sierra Mist Free, Diet Orange Crush, Fresca and Diet Mountain Dew. Colas, including Caffeine Free Diet Coke, Coke Zero, Caffeine Free Diet Pepsi and Diet Coke with Lime, had the lowest total alkali (less than 1.0 mEq/l). There was no significant correlation between beverage pH and total alkali content. Several commonly consumed diet sodas contain moderate amounts of citrate as alkali and total alkali. This information is helpful for dietary recommendations in patients with calcium nephrolithiasis, specifically those with hypocitraturia. It may also be useful in patients with low urine pH and uric acid stones. Beverage malate content is also important since malate ingestion increases the total alkali delivered, which in turn augments citraturia and increases urine pH. Copyright

Acetylated starch of Ofada rice as a sustained polymer in ...

African Journals Online (AJOL)

Objectives: To formulate and evaluate repaglinide microspheres using acetylated starch of the indigenous rice species Oryza glaberrima Steud (Ofada) as polymer. Materials and Methods: Ofada rice starch was acetylated with acetic anhydride in pyridine (DS 2.68) and characterized for morphology (Scanning electron ...

An MRM-based workflow for absolute quantitation of lysine-acetylated metabolic enzymes in mouse liver.

Science.gov (United States)

Xu, Leilei; Wang, Fang; Xu, Ying; Wang, Yi; Zhang, Cuiping; Qin, Xue; Yu, Hongxiu; Yang, Pengyuan

2015-12-07

As a key post-translational modification mechanism, protein acetylation plays critical roles in regulating and/or coordinating cell metabolism. Acetylation is a prevalent modification process in enzymes. Protein acetylation modification occurs in sub-stoichiometric amounts; therefore extracting biologically meaningful information from these acetylation sites requires an adaptable, sensitive, specific, and robust method for their quantification. In this work, we combine immunoassays and multiple reaction monitoring-mass spectrometry (MRM-MS) technology to develop an absolute quantification for acetylation modification. With this hybrid method, we quantified the acetylation level of metabolic enzymes, which could demonstrate the regulatory mechanisms of the studied enzymes. The development of this quantitative workflow is a pivotal step for advancing our knowledge and understanding of the regulatory effects of protein acetylation in physiology and pathophysiology.

Cupric citrate as growth promoter for broiler chickens in different rearing stages

Energy Technology Data Exchange (ETDEWEB)

Brainer, Monica Maria de Almeida [EAFCe, Ceres, GO (Brazil). Dept. de Zootecnia; Menten, Jose Fernando Machado; Vale, Marcos Martinez do; Morais, Sonia Cristina Daroz de [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz (ESALQ). Dept. de Zootecnia]. E-mail: jfmmente@esalq.usp.br

2003-07-01

Feeding cupric citrate as alternative to cupric sulfate to broilers has been suggested in the literature. Day-old male broiler chicks (1,200) were used in an experiment to evaluate the efficacy of cupric citrate supplementation (75 mg Cu kg-1) during the 1-21, 22-42 or 1-42 d periods in comparison to an unsupplemented diet and a diet supplemented with cupric sulfate (200 mg Cu kg-1, 1-42 d). A randomized block design was used, with five treatments, six replicates and 40 birds per pen. The diets, based on corn and soybean meal, and water were offered ad libitum during the 42-day experimental period. Over the entire period, there was no effect of copper supplementation (P > 0.05) on bird live weight, weight gain, feed intake, feed conversion and mortality. Cupric citrate supplementation on the 22-42 d period resulted in worse feed conversion as compared to broilers receiving cupric sulfate (2.014 vs. 1.967, P < 0.05). Copper residues in the litter were reduced when broilers were fed cupric citrate, as compared to cupric sulfate (P < 0.01). The absence of response to copper supplementation can be attributed to the environmental and sanitary rearing conditions.

Cupric citrate as growth promoter for broiler chickens in different rearing stages

International Nuclear Information System (INIS)

Brainer, Monica Maria de Almeida; Menten, Jose Fernando Machado; Vale, Marcos Martinez do; Morais, Sonia Cristina Daroz de

2003-01-01

Feeding cupric citrate as alternative to cupric sulfate to broilers has been suggested in the literature. Day-old male broiler chicks (1,200) were used in an experiment to evaluate the efficacy of cupric citrate supplementation (75 mg Cu kg-1) during the 1-21, 22-42 or 1-42 d periods in comparison to an unsupplemented diet and a diet supplemented with cupric sulfate (200 mg Cu kg-1, 1-42 d). A randomized block design was used, with five treatments, six replicates and 40 birds per pen. The diets, based on corn and soybean meal, and water were offered ad libitum during the 42-day experimental period. Over the entire period, there was no effect of copper supplementation (P > 0.05) on bird live weight, weight gain, feed intake, feed conversion and mortality. Cupric citrate supplementation on the 22-42 d period resulted in worse feed conversion as compared to broilers receiving cupric sulfate (2.014 vs. 1.967, P < 0.05). Copper residues in the litter were reduced when broilers were fed cupric citrate, as compared to cupric sulfate (P < 0.01). The absence of response to copper supplementation can be attributed to the environmental and sanitary rearing conditions

Mechanism of host substrate acetylation by a YopJ family effector.

Science.gov (United States)

Zhang, Zhi-Min; Ma, Ka-Wai; Gao, Linfeng; Hu, Zhenquan; Schwizer, Simon; Ma, Wenbo; Song, Jikui

2017-07-24

The Yersinia outer protein J (YopJ) family of bacterial effectors depends on a novel acetyltransferase domain to acetylate signalling proteins from plant and animal hosts. However, the underlying mechanism is unclear. Here, we report the crystal structures of PopP2, a YopJ effector produced by the plant pathogen Ralstonia solanacearum, in complex with inositol hexaphosphate (InsP 6 ), acetyl-coenzyme A (AcCoA) and/or substrate Resistance to Ralstonia solanacearum 1 (RRS1-R) WRKY . PopP2 recognizes the WRKYGQK motif of RRS1-R WRKY to position a targeted lysine in the active site for acetylation. Importantly, the PopP2-RRS1-R WRKY association is allosterically regulated by InsP 6 binding, suggesting a previously unidentified role of the eukaryote-specific cofactor in substrate interaction. Furthermore, we provide evidence for the reaction intermediate of PopP2-mediated acetylation, an acetyl-cysteine covalent adduct, lending direct support to the 'ping-pong'-like catalytic mechanism proposed for YopJ effectors. Our study provides critical mechanistic insights into the virulence activity of YopJ class of acetyltransferases.

Functional analysis of the citrate activator CitO from Enterococcus faecalis implicates a divalent metal in ligand binding

Directory of Open Access Journals (Sweden)

Victor S. Blancato

2016-02-01

Full Text Available The regulator of citrate metabolism, CitO, from Enterococcus faecalis belongs to the FCD family within the GntR superfamily. In the presence of citrate, CitO binds to cis-acting sequences located upstream of the cit promoters inducing the expression of genes involved in citrate utilization. The quantification of the molecular binding affinities, performed by isothermal titration calorimetry (ITC, indicated that CitO has a high affinity for citrate (KD= 1.2±0.2 µM, while it did not recognize other metabolic intermediates. Based on a structural model of CitO where a putative small molecule and a metal binding site were identified, it was hypothesized that the metal ion is required for citrate binding. In agreement with this model, citrate binding to CitO sharply decreased when the protein was incubated with EDTA. This effect was reverted by the addition of Ni2+, and Zn2+ to a lesser extent. Structure-based site-directed mutagenesis was conducted and it was found that changes to alanine in residues Arg97 and His191 resulted in decreased binding affinities for citrate, as determined by EMSA and ITC. Further assays using lacZ fusions confirmed that these residues in CitO are involved in sensing citrate in vivo. These results indicate that the molecular modifications induced by a ligand and a metal binding in the C-terminal domain of CitO are required for optimal DNA binding activity, and consequently, transcriptional activation.

Trichostatin A induced histone acetylation causes decondensation of interphase chromatin.

NARCIS (Netherlands)

T.A. Knoch (Tobias); M. Wachsmuth (Malte); M. Frank-Stöhr (Monika); M. Stöhr (Michael); C.P. Bacher (Christian); K. Rippe (Karsten)

2004-01-01

textabstractThe effect of trichostatin A (TSA)-induced histone acetylation on the interphase chromatin structure was visualized in vivo with a HeLa cell line stably expressing histone H2A, which was fused to enhanced yellow fluorescent protein. The globally increased histone acetylation caused a

The small delta antigen of hepatitis delta virus is an acetylated protein and acetylation of lysine 72 may influence its cellular localization and viral RNA synthesis

International Nuclear Information System (INIS)

Mu, J.-J.; Tsay, Y.-G.; Juan, L.-J.; Fu, T.-F.; Huang, W.-H.; Chen, D.-S.; Chen, P.-J.

2004-01-01

Hepatitis delta virus (HDV) is a single-stranded RNA virus that encodes two viral nucleocapsid proteins named small and large form hepatitis delta antigen (S-HDAg and L-HDAg). The S-HDAg is essential for viral RNA replication while the L-HDAg is required for viral assembly. In this study, we demonstrated that HDAg are acetylated proteins. Metabolic labeling with [ 3 H]acetate revealed that both forms of HDAg could be acetylated in vivo. The histone acetyltransferase (HAT) domain of cellular acetyltransferase p300 could acetylate the full-length and the N-terminal 88 amino acids of S-HDAg in vitro. By mass spectrometric analysis of the modified protein, Lys-72 of S-HDAg was identified as one of the acetylation sites. Substitution of Lys-72 to Arg caused the mutant S-HDAg to redistribute from the nucleus to the cytoplasm. The mutant reduced viral RNA accumulation and resulted in the earlier appearance of L-HDAg. These results demonstrated that HDAg is an acetylated protein and mutation of HDAg at Lys-72 modulates HDAg subcellular localization and may participate in viral RNA nucleocytoplasmic shuttling and replication

Myositis ossificans with Ga-67 citrate positivity

International Nuclear Information System (INIS)

Moreno, A.J.; Yedinak, M.A.; Spicer, M.J.; Turnbull, G.L.; Byrd, B.F.; Brown, T.J.

1985-01-01

A 16 year-old boy presented with a firm mass within the left thigh. Ga-67 citrate and bone scintigraphy revealed soft tissue radiotracer accumulation within the mass lesion. Radiographs and xerography of the left thigh revealed calcification within the soft tissue mass typical of myositis ossificans. The patient's clinical course was uneventful

Citrate, a Ubiquitous Key Metabolite with Regulatory Function in the CNS

DEFF Research Database (Denmark)

Westergaard, Niels; Waagepetersen, Helle S; Belhage, Bo

2017-01-01

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 13C-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...

Comparison of technetium-99m methoxyisobutylisonitrile and gallium-67 citrate scanning in the assessment of lymphomas

International Nuclear Information System (INIS)

Ziegels, P.; Nocaudie, M.; Huglo, D.; Deveaux, M.; Detourmignies, L.; Wattel, E.; Marchandise, X.

1995-01-01

The aim of this study was to compare the value of scintigraphy using technetium-99m methoxy-isobutylisonitrile (MIBI) with that of scintigraphy using gallium-67 citrate in the assessment of Hodgkin's disease and non-Hodgkin's lymphoma and to relate these results with those of CT scan and MRI. Fifty-eight patients were included either for a follow-up examination or for monitoring of their treatment. Twenty-three residual masses were studied. A whole-body scan was performed, followed by single-photon emission computed tomography (SPET) 20 min after injection of 740 MBq of 99m Tc-MIBI and 72 h after injection of 185 MBq of 67 Ga citrate. The overall sensitivity of 99m Tc-MIBI and 67 Ga citrate was 71% and 68%, respectively, and the overall specificity was 76% and 44%, respectively. For residual masses, the sensitivity was 44% with both tracers and the specificity was 80% with 99m Tc-MIBI and 53% with 67 Ga citrate. The positive predictive values were 85% and 68% and the negative predictive values were 59% and 44%, respectively. The signal-to-background ratio was 1.5 for 99m Tc-MIBI and 2 for 67 Ga citrate. At present, 99m Tc-MIBI cannot replace 67 Ga citrate in the assessment of lymphomas. (orig.)

Small molecule inhibitors of bromodomain-acetyl-lysine interactions.

Science.gov (United States)

Brand, Michael; Measures, Angelina R; Measures, Angelina M; Wilson, Brian G; Cortopassi, Wilian A; Alexander, Rikki; Höss, Matthias; Hewings, David S; Rooney, Timothy P C; Paton, Robert S; Conway, Stuart J

2015-01-16

Bromodomains are protein modules that bind to acetylated lysine residues. Their interaction with histone proteins suggests that they function as "readers" of histone lysine acetylation, a component of the proposed "histone code". Bromodomain-containing proteins are often found as components of larger protein complexes with roles in fundamental cellular process including transcription. The publication of two potent ligands for the BET bromodomains in 2010 demonstrated that small molecules can inhibit the bromodomain-acetyl-lysine protein-protein interaction. These molecules display strong phenotypic effects in a number of cell lines and affect a range of cancers in vivo. This work stimulated intense interest in developing further ligands for the BET bromodomains and the design of ligands for non-BET bromodomains. Here we review the recent progress in the field with particular attention paid to ligand design, the assays employed in early ligand discovery, and the use of computational approaches to inform ligand design.

Effect of [L-Carnitine] on acetyl-L-carnitine production by heart mitochondria

International Nuclear Information System (INIS)

Bieber, L.L.; Lilly, K.; Lysiak, W.

1986-01-01

The authors recently reported a large efflux of acetyl-L-carnitine from rat heart mitochondria during state 3 respiration with pyruvate as substrate both in the presence and absence of malate. In this series of experiments, the effect of the concentration of L-carnitine on the efflux of acetyl-L-carnitine and on the production of 14 CO 2 from 2- 14 C-pyruvate was determined. Maximum acetylcarnitine production (approximately 25 n moles/min/mg protein) was obtained at 3-5 mM L-carnitine in the absence of added malate. 14 CO 2 production decreased as the concentration of L-carnitine increased; it plateaued at 3-5 mM L-carnitine. These data indicate carnitine can stimulate flux of pyruvate through pyruvate dehydrogenase and can reduce flux of acetyl CoA through the Krebs cycle by acting as an acceptor of the acetyl moieties of acetyl CoA generated by pyruvate dehydrogenase

Acetylation curtails nucleosome binding, not stable nucleosome remodeling, by FoxO1

International Nuclear Information System (INIS)

Hatta, M.; Liu, F.; Cirillo, L.A.

2009-01-01

Transcriptional activity of FoxO factors is controlled through the actions of multiple growth factors signaling through protein kinase B, whereby phosphorylation of FoxO factors inhibits FoxO-mediated transactivation by promoting nuclear export. Phosphorylation of FoxO factors is enhanced by p300-mediated acetylation, which decreases their affinity for DNA. The negative effect of acetylation on FoxO DNA binding, together with nuclear FoxO mobility, is eliminated by over-expression of the de-acetylase Sirt1, suggesting that acetylation mobilizes FoxO factors in chromatin for inducible gene expression. Here, we show that acetylation significantly curtails the affinity of FoxO1 for its binding sites in nucleosomal DNA but has no effect on either stable nucleosome binding or remodeling by this factor. We suggest that, while acetylation provides a first, essential step toward mobilizing FoxO factors for inducible gene repression, additional mechanisms exist for overcoming their inherent capacity to stably bind and remodel nuclear chromatin.

Fragrance material review on acetyl carene.

Science.gov (United States)

Scognamiglio, J; Letizia, C S; Api, A M

2013-12-01

A toxicologic and dermatologic review of acetyl carene when used as a fragrance ingredient is presented. Acetyl carene is a member of the fragrance structural group Alkyl Cyclic Ketones. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for acetyl carene were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, and skin sensitization data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013A Toxicologic and dermatologic assessment of alkyl cyclic ketones when used as fragrance ingredients. (submitted for publication).) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. Copyright © 2013. Published by Elsevier Ltd.

Flexible biodegradable citrate-based polymeric step-index optical fiber.

Science.gov (United States)

Shan, Dingying; Zhang, Chenji; Kalaba, Surge; Mehta, Nikhil; Kim, Gloria B; Liu, Zhiwen; Yang, Jian

2017-10-01

Implanting fiber optical waveguides into tissue or organs for light delivery and collection is among the most effective ways to overcome the issue of tissue turbidity, a long-standing obstacle for biomedical optical technologies. Here, we report a citrate-based material platform with engineerable opto-mechano-biological properties and demonstrate a new type of biodegradable, biocompatible, and low-loss step-index optical fiber for organ-scale light delivery and collection. By leveraging the rich designability and processibility of citrate-based biodegradable polymers, two exemplary biodegradable elastomers with a fine refractive index difference and yet matched mechanical properties and biodegradation profiles were developed. Furthermore, we developed a two-step fabrication method to fabricate flexible and low-loss (0.4 db/cm) optical fibers, and performed systematic characterizations to study optical, spectroscopic, mechanical, and biodegradable properties. In addition, we demonstrated the proof of concept of image transmission through the citrate-based polymeric optical fibers and conducted in vivo deep tissue light delivery and fluorescence sensing in a Sprague-Dawley (SD) rat, laying the groundwork for realizing future implantable devices for long-term implantation where deep-tissue light delivery, sensing and imaging are desired, such as cell, tissue, and scaffold imaging in regenerative medicine and in vivo optogenetic stimulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Changes in nuclear protein acetylation in u.v.-damaged human cells

International Nuclear Information System (INIS)

Ramanathan, B.; Smerdon, M.J.

1986-01-01

The levels of nuclear protein acetylation in u.v.-irradiated human fibroblasts have been investigated. Initially, we measured the levels of acetylation in total acid-soluble nuclear proteins and observed two distinct differences between the irradiated and unirradiated (control) cells. Immediately after irradiation, there is a 'wave' of protein hyperacetylation that lasts for 2-6 h, followed by a hypoacetylation phase, lasting for many hours, and the total level of acetylation does not return to that of control cells until 24-72 h after u.v. damage. Both the magnitude and duration of each phase is dependent on the dose of u.v. light used. The wave of hyperacetylation is more pronounced at low u.v. doses, while the wave of hypoacetylation is more pronounced at higher u.v. doses. Furthermore, the duration of each phase is prolonged when cells are exposed to 2 mM hydroxyurea, an agent which retards the rate of excision repair at u.v.-damaged sites. Examinations of the acetylation levels of the individual nuclear proteins indicated that acetylation of the core histones follows the same pattern observed for the total acid-soluble protein fractions. Furthermore, these were the only major proteins in the total acid-soluble fraction observed to undergo the early, rapid hyperacetylation immediately following u.v. damage. These results raise the possibility that a causal relationship exists between nuclear protein acetylation and nucleotide excision repair of DNA in human cells. (author)

Ion exchange behaviour of citrate and EDTA anions on strong and weak base organic ion exchangers

International Nuclear Information System (INIS)

Askarieh, M.M.; White, D.A.

1988-01-01

The exchange of citrate and EDTA ions with two strong base and two weak base exchangers is considered. Citrate and EDTA analysis for this work was performed using a colorimetric method developed here. The ions most selectively exchanged on the resins are H 2 cit - and H 2 EDTA 2- , though EDTA is generally less strongly sorbed on strong base resins. In contact with weak base resins, deprotonation of the resin occurs during ion exchange with a noticeable drop in solution pH. Although EDTA sorption can be reversed by nitric acid, citrate ions are significantly held on the resin at low pH. The exchange of citrate can be made reversible if bicarbonate is added to the initial solutions. Alkaline regeneration of exchangers loaded with EDTA proved to be very effective. (author)

Sodium citrate blood contamination by K2 -ethylenediaminetetraacetic acid (EDTA): impact on routine coagulation testing.

Science.gov (United States)

Lima-Oliveira, G; Salvagno, G L; Danese, E; Favaloro, E J; Guidi, G C; Lippi, G

2015-06-01

The potential cross-contamination of additives between primary blood tubes is a well-known problem during sample collection. The aim of this study was to assess the impact of citrated blood contamination with different amounts of dipotassium ethylenediaminetetraacetic (K2 EDTA blood) on activated partial thromboplastin time (APTT), prothrombin time (PT), and fibrinogen. Blood was collected from 15 ostensibly healthy volunteers into four 0.109 m citrate blood tubes followed by one K2 EDTA blood tube. The citrate tubes of each subject were pooled and divided in five aliquots. The whole blood of the K2 EDTA tube was then added in scalar amounts to autologous citrated blood aliquots, to obtain K2 EDTA contamination ranging from 0% to 43%, and thus mimic potential pre-analytical contamination. A statistically and clinically significant prolongation was observed for both APTT and PT between 29% and 43% K2 EDTA contamination, whereas the decrease of fibrinogen values became statistically and clinically significant at 43% K2 EDTA contamination. The results of this investigation show that contamination of citrated blood with as much as 29% of K2 EDTA blood generates a significant bias in results of routine clotting assays. This has serious implications for patient safety and management. © 2014 John Wiley & Sons Ltd.

Biodegradation of metal citrate complexes and implications for toxic-metal mobility

International Nuclear Information System (INIS)

Francis, A.J.; Dodge, C.J.; Gillow, J.B.

1992-01-01

The presence of synthetic and naturally occurring chelating agents in nuclear and toxic-metal wastes is a major concern because of their potential to enhance mobilization of metal ions away from the disposal sites. Of particular interest is citric acid, which is present in low-level and transuranic radioactive wastes and in domestic and industrial wastes (as washing fluids, for instance), as well as being found naturally. Citrate ions form multidentate, stable complexes with a variety of toxic metals and radionuclides; but biodegradation of these complexes, precipitating the metal ions as insoluble hydroxides, oxides or other salts, may retard migration. Here we report a study of the biodegradation of citrate complexes of Ca, Fe(II), Fe(III), Cd, Cu, Ni, Pb and U. Several of these complexes were not readily degraded by bacteria, and the biodegradability depended on the chemical nature of the complex, not on the toxicity of the metal to the bacteria. This resistance to biodegradation implies that citrate complexation may play an important part in migration of these hazardous wastes. (author)

Highly selective and sensitive macrocycle-based dinuclear foldamer for fluorometric and colorimetric sensing of citrate in water.

Science.gov (United States)

Rhaman, Md Mhahabubur; Hasan, Mohammad H; Alamgir, Azmain; Xu, Lihua; Powell, Douglas R; Wong, Bryan M; Tandon, Ritesh; Hossain, Md Alamgir

2018-01-10

The selective detection of citrate anions is essential for various biological functions in living systems. A quantitative assessment of citrate is required for the diagnosis of various diseases in the human body; however, it is extremely challenging to develop efficient fluorescence and color-detecting molecular probes for sensing citrate in water. Herein, we report a macrocycle-based dinuclear foldamer (1) assembled with eosin Y (EY) that has been studied for anion binding by fluorescence and colorimetric techniques in water at neutral pH. Results from the fluorescence titrations reveal that the 1·EY ensemble strongly binds citrate anions, showing remarkable selectivity over a wide range of inorganic and carboxylate anions. The addition of citrate anions to the 1·EY adduct led to a large fluorescence enhancement, displaying a detectable color change under both visible and UV light in water up to 2 μmol. The biocompatibility of 1·EY as an intracellular carrier in a biological system was evaluated on primary human foreskin fibroblast (HF) cells, showing an excellent cell viability. The strong binding properties of the ensemble allow it to be used as a highly sensitive, detective probe for biologically relevant citrate anions in various applications.

Inhibitory effect of fentanyl citrate on the release of endothlin-1 induced by bradykinin in melanoma cells.

Science.gov (United States)

Andoh, Tsugunobu; Shinohara, Akira; Kuraishi, Yasushi

2017-02-01

Our previous study showed that the μ-opioid receptor agonist fentanyl citrate inhibits endothelin-1-and bradykinin-mediated pain responses in mice orthotopically inoculated with melanoma cells. We also demonstrated that bradykinin induces endothelin-1 secretion in melanoma cells. However, the analgesic mechanisms of fentanyl citrate remain unclear. Thus, the present study was conducted to determine whether fentanyl citrate affects bradykinin-induced endothelin-1 secretion in B16-BL6 melanoma cells. The amount of endothelin-1 in the culture medium was measured using an enzyme immunoassay. The expression of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL/6 melanoma cells was determined using immunocytochemistry. Fentanyl citrate inhibited bradykinin-induced endothelin-1 secretion. The inhibitory effect of fentanyl citrate on the secretion of endothelin-1 was attenuated by the μ-opioid receptor antagonist naloxone methiodide. The immunoreactivities of endothelin-1, kinin B 2 receptors, and μ-opioid receptors in B16-BL6 melanoma cells were observed. These results suggest that fentanyl citrate regulates bradykinin-induced endothelin-1 secretion through μ-opioid receptors in melanoma cells. Copyright © 2016 Institute of Pharmacology, Polish Academy of Sciences. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

21 CFR 172.370 - Iron-choline citrate complex.

Science.gov (United States)

2010-04-01

....370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.370 Iron-choline citrate complex. Iron-choline...

DNA Damage-Induced Acetylation of Lysine 3016 of ATM Activates ATM Kinase Activity▿ †

OpenAIRE

Sun, Yingli; Xu, Ye; Roy, Kanaklata; Price, Brendan D.

2007-01-01

The ATM protein kinase is essential for cells to repair and survive genotoxic events. The activation of ATM's kinase activity involves acetylation of ATM by the Tip60 histone acetyltransferase. In this study, systematic mutagenesis of lysine residues was used to identify regulatory ATM acetylation sites. The results identify a single acetylation site at lysine 3016, which is located in the highly conserved C-terminal FATC domain adjacent to the kinase domain. Antibodies specific for acetyl-ly...

Biodegradation of tributyl phosphate, an organosphate triester, by aerobic granular biofilms

Energy Technology Data Exchange (ETDEWEB)

Nancharaiah, Y.V., E-mail: venkatany@gmail.com; Kiran Kumar Reddy, G.; Krishna Mohan, T.V.; Venugopalan, V.P.

2015-02-11

Graphical abstract: - Highlights: • Aerobic granular biomass was cultivated by feeding TBP along with acetate. • Rapid biodegradation of TBP when used as a co-substrate or as the sole carbon source. • Biodegradation of 2 mM TBP in 5 h with degradation rate of 0.4 μmol mL{sup −1} h{sup −1}. • High phosphatase activity was observed in TBP-degrading granular biomass. • n-Butanol, hydrolyzed product of TBP, was rapidly metabolized by aerobic granules. - Abstract: Tributyl phosphate (TBP) is commercially used in large volumes for reprocessing of spent nuclear fuel. TBP is a very stable compound and persistent in natural environments and it is not removed in conventional wastewater treatment plants. In this study, cultivation of aerobic granular biofilms in a sequencing batch reactor was investigated for efficient biodegradation of TBP. Enrichment of TBP-degrading strains resulted in efficient degradation of TBP as sole carbon or along with acetate. Complete biodegradation of 2 mM of TBP was achieved within 5 h with a degradation rate of 0.4 μmol mL{sup −1} h{sup −1}. TBP biodegradation was accompanied by release of inorganic phosphate in stoichiometric amounts. n-Butanol, hydrolysed product of TBP was rapidly biodegraded. But, dibutyl phosphate, a putative intermediate of TBP degradation was only partially degraded pointing to an alternative degradation pathway. Phosphatase activity was 22- and 7.5-fold higher in TBP-degrading biofilms as compared to bioflocs and acetate-fed aerobic granules. Community analysis by terminal restriction length polymorphism revealed presence of 30 different bacterial strains. Seven bacterial stains, including Sphingobium sp. a known TBP degrader were isolated. The results show that aerobic granular biofilms are promising for treatment of TBP-bearing wastes or ex situ bioremediation of TBP-contaminated sites.

Biodegradation of tributyl phosphate, an organosphate triester, by aerobic granular biofilms

International Nuclear Information System (INIS)

Nancharaiah, Y.V.; Kiran Kumar Reddy, G.; Krishna Mohan, T.V.; Venugopalan, V.P.

2015-01-01

Graphical abstract: - Highlights: • Aerobic granular biomass was cultivated by feeding TBP along with acetate. • Rapid biodegradation of TBP when used as a co-substrate or as the sole carbon source. • Biodegradation of 2 mM TBP in 5 h with degradation rate of 0.4 μmol mL −1 h −1 . • High phosphatase activity was observed in TBP-degrading granular biomass. • n-Butanol, hydrolyzed product of TBP, was rapidly metabolized by aerobic granules. - Abstract: Tributyl phosphate (TBP) is commercially used in large volumes for reprocessing of spent nuclear fuel. TBP is a very stable compound and persistent in natural environments and it is not removed in conventional wastewater treatment plants. In this study, cultivation of aerobic granular biofilms in a sequencing batch reactor was investigated for efficient biodegradation of TBP. Enrichment of TBP-degrading strains resulted in efficient degradation of TBP as sole carbon or along with acetate. Complete biodegradation of 2 mM of TBP was achieved within 5 h with a degradation rate of 0.4 μmol mL −1 h −1 . TBP biodegradation was accompanied by release of inorganic phosphate in stoichiometric amounts. n-Butanol, hydrolysed product of TBP was rapidly biodegraded. But, dibutyl phosphate, a putative intermediate of TBP degradation was only partially degraded pointing to an alternative degradation pathway. Phosphatase activity was 22- and 7.5-fold higher in TBP-degrading biofilms as compared to bioflocs and acetate-fed aerobic granules. Community analysis by terminal restriction length polymorphism revealed presence of 30 different bacterial strains. Seven bacterial stains, including Sphingobium sp. a known TBP degrader were isolated. The results show that aerobic granular biofilms are promising for treatment of TBP-bearing wastes or ex situ bioremediation of TBP-contaminated sites

Photometric determination of the composition and dissociation constants of niobium (5) citrate complexes

International Nuclear Information System (INIS)

Grigor'eva, V.V.; Golubeva, I.V.

1979-01-01

Niobium (5) citrate complexes in aqueous solution (pH 1-6) are investigated. To determine the complexes composition the metal-indicator method has been applied. Experimental data have been treated by the method of equilibrium shift using somewhat changed variant of the metal-indicator method. The complex ion charge in the solution has been determined by the ion-exchange method. Dissociation constants of citrate complexes have been determined photometrically

Renal Localization of {sup 67}Ga Citrate in Noninfectious Nephritis

Energy Technology Data Exchange (ETDEWEB)

Lee, Kang Wook; Jeong, Min Soo; Rhee, Sunn Kgoo; Kim, Sam Yong; Shin, Young Tai; Ro, Heung Kyu [Chungnam University College of Medicine, Deajeon (Korea, Republic of)

1992-07-15

{sup 67}Ga citrate scan has been requested for detection or follow-up of inflammatory or neoplastic disease. Visualization of {sup 67}Ga citrate in the kidneys at 48 and 72 hr post injection is usually interpreted as evidence of renal pathology. But precise mechanisms of abnormal {sup 67}Ga uptake in kidneys were unknown. We undertook a study to determine the clinical value of {sup 67}Ga citrate imaging of the kidneys in 68 patients with primary or secondary nephropathy confirmed by renal biopsy and 66 control patients without renal disease. Renal uptake in 48 to 72 hr images was graded as follows: Grade 0=background activity;1=faint uptake greater than background; 2=definite uptake, but less than lumbar vertebrae;3 same uptake as lumbar vertebrae, but less than liver; 4=same or higher uptake than liver. The results were as follows. 1) 42 of 68(62%) patients with noninfectious nephritis showed grade 2 or higher {sup 67}Ga renal uptake but only 10 percent of control patients showed similar uptake. 2) In 14 patients with systemic lupus erythematosus, 8 of 9 (89%) patients with lupus nephritis exhibited marked renal uptake. 3) 36 of 41 patients (88%) with combined nephrotic syndrome showed Grade 2 or higher renal uptake. 4) Renal {sup 67}Ga uptake was correlated with clinical severity of nephrotic syndrome determined by serum albumin level, 24 hr urine protein excretion and serum lipid levels. 5) After complete remission of nephrotic syndrome, renal uptake in all 8 patients who were initially Grade 3 or 4, decreased to Grade 1 or 0. In conclusion, we think that the mechanism of renal {sup 67}Ga uptake in nephrotic syndrome might be related to the pathogenesis of nephrotic syndrome. In systemic lupus erythematosus, {sup 67}Ga citrate scan is useful in predicting renal involvement.

Colon transit scintigraphy by 67 Ga citrate for idiopathic constitution

International Nuclear Information System (INIS)

Neshandar Asll, I.; Ehsani, M.J.; Javadi, H.

2005-01-01

Background/objective: segmental colonic transit studies are important in patients with severe constipation. This study is the first Iranian preliminary survey of colonic transit scintigraphy using 67 Ga -citrate as a new method in constipated patients with normal radiographic and colonoscopic evaluations. Patients and methods: thirteen patients with idiopathic constipation underwent colon transit scintigraphy. After oral administration of 6-7 MBq Ga-citrates, serial abdominal images were taken up to 72 hours. Pattern classification wa s performed visually according to the distribution of radioactivity, Scintigraphic parameters such as geometric mean center of seq mental retention of tracer, as well as mean ac activity profiles and colonic tracer half-clearance time were calculated Results: Three patterns of colonic transit scintigraphy were recognized. Nine patients had the normal pattern, i.e. excellent propagation of ac activity. Three patients had the colonic inertia pattern with marked retention of activity in the transverse colon and splenic flexure at 48 hours, One patient had significant retention of activity in the recto sigmoid at 72 hours, defined as functional recto sigmoid obstruction . No significant difference was seen in GMC24h between the normal pattern and colonic inertia (P4.053), but GMC48h and GMC72h markedly differed between the two groups (P50.0 16 and 0.025 respectively). 'The mean half clearance time of the two groups was di different (P4.017). Our results are well compatible with scintigraphic diagnostic criteria in different patterns of colonic transit defined by other studies with different radiotracer. Conclusion: oral 67 Ga -citrate colon transit scintigraphy is a feasible method to evaluate idiopathic constipation and seems to be a suitable surrogate for radio-opaque markers. Keywords: oral 67 Ga -citrate, colonic transit study, idiopathic constipation, scintigraphy

Acetylation of spermidine and methylglyoxal bis(guanylhydrazone) in baby-hamster kidney cells (BHK-21/C13).

Science.gov (United States)

Wallace, H M; Nuttall, M E; Robinson, F C

1988-01-01

Treatment of BHK-21/C13 cells with methylglyoxal bis(guanylhydrazone) (MGBG) induced the cytosolic form of spermidine N1-acetyltransferase. It stabilized the enzyme against proteolytic degradation, but the drug did not affect the enzyme activity in vitro. MGBG was itself acetylated by BHK-21/C13 cells, but at only one-tenth the rate at which spermidine was acetylated. Acetylation occurred almost exclusively in the nuclear fraction. The product was identified as N-acetyl-MGBG by h.p.l.c., by using [3H]acetyl-CoA and [14C]MGBG as co-substrates. The results suggest that the acetylation of MGBG by BHK-21/C13 cells occurs by a different acetyltransferase enzyme from that which acetylates spermidine. PMID:3421945

Proteome-wide analysis of lysine acetylation suggests its broad regulatory scope in Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Henriksen, Peter; Wagner, Sebastian Alexander; Weinert, Brian Tate

2012-01-01

Post-translational modification of proteins by lysine acetylation plays important regulatory roles in living cells. The budding yeast Saccharomyces cerevisiae is a widely used unicellular eukaryotic model organism in biomedical research. S. cerevisiae contains several evolutionary conserved lysine...... acetyltransferases and deacetylases. However, only a few dozen acetylation sites in S. cerevisiae are known, presenting a major obstacle for further understanding the regulatory roles of acetylation in this organism. Here we use high resolution mass spectrometry to identify about 4000 lysine acetylation sites in S....... cerevisiae. Acetylated proteins are implicated in the regulation of diverse cytoplasmic and nuclear processes including chromatin organization, mitochondrial metabolism, and protein synthesis. Bioinformatic analysis of yeast acetylation sites shows that acetylated lysines are significantly more conserved...

The role of tannic acid and sodium citrate in the synthesis of silver nanoparticles

Science.gov (United States)

Ranoszek-Soliwoda, Katarzyna; Tomaszewska, Emilia; Socha, Ewelina; Krzyczmonik, Pawel; Ignaczak, Anna; Orlowski, Piotr; Krzyzowska, Małgorzata; Celichowski, Grzegorz; Grobelny, Jaroslaw

2017-08-01

We describe herein the significance of a sodium citrate and tannic acid mixture in the synthesis of spherical silver nanoparticles (AgNPs). Monodisperse AgNPs were synthesized via reduction of silver nitrate using a mixture of two chemical agents: sodium citrate and tannic acid. The shape, size and size distribution of silver particles were determined by UV-Vis spectroscopy, dynamic light scattering (DLS) and scanning transmission electron microscopy (STEM). Special attention is given to understanding and experimentally confirming the exact role of the reagents (sodium citrate and tannic acid present in the reaction mixture) in AgNP synthesis. The oxidation and reduction potentials of silver, tannic acid and sodium citrate in their mixtures were determined using cyclic voltammetry. Possible structures of tannic acid and its adducts with citric acid were investigated in aqueous solution by performing computer simulations in conjunction with the semi-empirical PM7 method. The lowest energy structures found from the preliminary conformational search are shown, and the strength of the interaction between the two molecules was calculated. The compounds present on the surface of the AgNPs were identified using FT-IR spectroscopy, and the results are compared with the IR spectrum of tannic acid theoretically calculated using PM6 and PM7 methods. The obtained results clearly indicate that the combined use of sodium citrate and tannic acid produces monodisperse spherical AgNPs, as it allows control of the nucleation, growth and stabilization of the synthesis process. [Figure not available: see fulltext.

Novel myelin penta- and hexa-acetyl-galactosyl-ceramides: structural characterization and immunoreactivity in cerebrospinal fluid

DEFF Research Database (Denmark)

Podbielska, Maria; Dasgupta, Somsankar; Levery, Steven B

2010-01-01

Fast migrating cerebrosides (FMC) are derivatives of galactosylceramide (GalCer). The structures of the most hydrophobic FMC-5, FMC-6, and FMC-7 were determined by electrospray ionization linear ion-trap mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy complementing previous...... NMR spectroscopy and gas chromatography-mass spectrometry to be 3-O-acetyl-sphingosine-GalCer derivatives with galactose O-acetyl modifications. FMC-5 and FMC-6 are 3-O-acetyl-sphingosine-2,3,4,6-tetra-O-acetyl-GalCer with nonhydroxy and hydroxy-N-fatty-acids, while FMC-7 has an additional O...... Mycoplasma fermentans. The cross-reactivity of highly acetylated GalCer with microbial acyl-glycolipid raises the possibility that myelin-O-acetyl-cerebrosides, bacterial infection, and neurological disease are linked....

Women taking the “blue pill” (sildenafil citrate: such a big deal?

Directory of Open Access Journals (Sweden)

Lo Monte G

2014-11-01

Full Text Available Giuseppe Lo Monte, Angela Graziano, Isabella Piva, Roberto Marci Department of Morphology, Surgery, and Experimental Medicine, University of Ferrara, Ferrara, Italy Abstract: For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra® in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate should be kept as the last option. Keywords: phosphodiesterase type 5 inhibitors, female sexual arousal disorder (FSAD, sildenafil citrate

A fundamental study on brain scanning with sup(99m)Tc-citrate

International Nuclear Information System (INIS)

Ishii, Katsumi; Kobayashi, Takeshi; Yamada, Nobuaki; Horiike, Shigeharu; Nakazawa, Keiji

1978-01-01

We examined the sup(99m)Tc-citrate obtained by labelling citrate with sup(99m)Tc-pertechnetate using Solcocitran Kit. For our fundamental study--we measured the ratio of labelling by means of paper chromatography. By picking out each organs of each rats we also measured the velocity at which radiopharmaceuticals disappeared in each of their organs, and the distribution of radio-pharmaceuticals in their organs. For our clinical study--we performed brain scanning on 47 patients. The following are the results; Citrate was labelled as much as 99 - 95% into sup(99m)Tc-pertechnetate. The velocity of disappearance in each organ of the rats was quicker than in the case of sup(99m)TcO 4 - . Accumulation in the choroid plexus and salivary gland was not obserbed despite the fact that we did not use KClo 4 , and images of brain tumor were obtainable to a high degree. (author)

The Effect of Hypochlorite Oxidation and Acetylation on Some of the ...

African Journals Online (AJOL)

The study evaluated the effect of hypochlorite oxidation and acetylation on some physicochemical properties of Icacina trichantha starch. The native and modified (oxidized and acetylated) starches were studied with respect to Infrared spectroscopy(IR), microscopy, gelatinization, swelling power, solubility index, amylose ...

Multi-step rearrangement mechanism for acetyl cedrene to the hydrocarbon follower

DEFF Research Database (Denmark)

Paknikar, Shashikumar Keshav; Kamounah, Fadhil S.; Hansen, Poul Erik

2017-01-01

Conversion of acetyl cedrene (2) to its follower (3) using acetic anhydride and polyphosphoric acid involves a multi-step cationic molecular rearrangement, which is consistent with deuteriation and 1-13C labeling studies of acetyl cedrene. The key step involves cyclopropylcarbinyl cation-cyclopro...

Characterization, Leaching, and Filtration Testing for Tributyl Phosphate (TBP, Group 7) Actual Waste Sample Composites

Energy Technology Data Exchange (ETDEWEB)

Edwards, Matthew K.; Billing, Justin M.; Blanchard, David L.; Buck, Edgar C.; Casella, Amanda J.; Casella, Andrew M.; Crum, J. V.; Daniel, Richard C.; Draper, Kathryn E.; Fiskum, Sandra K.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Snow, Lanee A.; Swoboda, Robert G.

2009-03-09

.A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. The tributyl phosphate sludge (TBP, Group 7) is the subject of this report. The Group 7 waste was anticipated to be high in phosphorus as well as aluminum in the form of gibbsite. Both are believed to exist in sufficient quantities in the Group 7 waste to address leaching behavior. Thus, the focus of the Group 7 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467.

Proteomic Analysis of Lysine Acetylation Sites in Rat Tissues Reveals Organ Specificity and Subcellular Patterns

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Alicia Lundby

2012-08-01

Full Text Available Lysine acetylation is a major posttranslational modification involved in a broad array of physiological functions. Here, we provide an organ-wide map of lysine acetylation sites from 16 rat tissues analyzed by high-resolution tandem mass spectrometry. We quantify 15,474 modification sites on 4,541 proteins and provide the data set as a web-based database. We demonstrate that lysine acetylation displays site-specific sequence motifs that diverge between cellular compartments, with a significant fraction of nuclear sites conforming to the consensus motifs G-AcK and AcK-P. Our data set reveals that the subcellular acetylation distribution is tissue-type dependent and that acetylation targets tissue-specific pathways involved in fundamental physiological processes. We compare lysine acetylation patterns for rat as well as human skeletal muscle biopsies and demonstrate its general involvement in muscle contraction. Furthermore, we illustrate that acetylation of fructose-bisphosphate aldolase and glycerol-3-phosphate dehydrogenase serves as a cellular mechanism to switch off enzymatic activity.

Mitochondrial storage form of acetyl CoA carboxylase in fasted and alloxan diabetic rats

International Nuclear Information System (INIS)

Roman-Lopez, C.R.; Allred, J.B.

1986-01-01

Sodium dodecyl sulfate-denatured biotinyl proteins will bind [ 14 C]methyl avidin which remains bound through polyacrylamide gel electrophoresis. The method has been used to demonstrate the presence of two high molecular weight subunit forms of acetyl CoA carboxylase in rat liver cytoplasm, both of which are precipitated by antibody to purifed rat liver acetyl CoA carboxylase prepared from sheep serum. Rat liver mitochondria contained five distinct biotinyl protein subunits, the two largest of which have been identified as acetyl CoA carboxylase subunits on the basis of precipitation by anti-acetyl CoA carboxylase antibody. The small quantity of acetyl CoA carboxylase associated with rat liver microsomes could be attributed to cytoplasmic contamination. The binding of radioactive avidin is sufficiently tight to use as a measure of the quantity of acetyl CoA carboxylase. The quantity and activity of the cytoplasmic enzyme was reduced in fasted and in alloxan diabetic rats compared to that in fed controls but the quantity of the enzyme associated with isolated mitochondria was not reduced. The results indicate that there is a mitochondrial storage form of acetyl CoA carboxylase

Protective Effects of Acetylation on the Pathological Reactions of the Lens Crystallins with Homocysteine Thiolactone.

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Zeinab Moafian

Full Text Available Various post-translational lens crystallins modifications result in structural and functional insults, contributing to the development of lens opacity and cataract disorders. Lens crystallins are potential targets of homocysteinylation, particularly under hyperhomocysteinemia which has been indicated in various eye diseases. Since both homocysteinylation and acetylation primarily occur on protein free amino groups, we applied different spectroscopic methods and gel mobility shift analysis to examine the possible preventive role of acetylation against homocysteinylation. Lens crystallins were extensively acetylated in the presence of acetic anhydride and then subjected to homocysteinylation in the presence of homocysteine thiolactone (HCTL. Extensive acetylation of the lens crystallins results in partial structural alteration and enhancement of their stability, as well as improvement of α-crystallin chaperone-like activity. In addition, acetylation partially prevents HCTL-induced structural alteration and aggregation of lens crystallins. Also, acetylation protects against HCTL-induced loss of α-crystallin chaperone activity. Additionally, subsequent acetylation and homocysteinylation cause significant proteolytic degradation of crystallins. Therefore, further experimentation is required in order to judge effectively the preventative role of acetylation on the structural and functional insults induced by homocysteinylation of lens crystallins.

The Effect of Polymer Molecular Weight on Citrate Crosslinked ...

African Journals Online (AJOL)

Erah

Purpose: To develop citrate crosslinked chitosan films using chitosan of different molecular weights. (MW) in .... left to stand until trapped air bubbles ... blotted out carefully with filter paper from the .... potential as biodegradable stent coatings. J.

A Comparison of Secondary Polycythemia in Hypogonadal Men Treated with Clomiphene Citrate versus Testosterone Replacement: A Multi-Institutional Study.

Science.gov (United States)

Wheeler, Karen M; Smith, Ryan P; Kumar, Raj A; Setia, Shaan; Costabile, Raymond A; Kavoussi, Parviz K

2017-04-01

We evaluated the relative prevalence of secondary polycythemia in hypogonadal men treated with clomiphene citrate or testosterone replacement therapy. In this retrospective, multi-institutional study, we included 188 men who received clomiphene citrate and 175 who received testosterone replacement therapy with symptomatic hypogonadism. The overall prevalence and ORs of secondary polycythemia for clomiphene citrate treatment vs testosterone replacement were primarily measured, as were baseline characteristics. Subset analysis included polycythemia rates for different types of testosterone replacement therapy. Overall, men on testosterone replacement therapy were older than clomiphene citrate treated men (age 51.5 vs 38 years). Men on testosterone replacement had longer treatment duration than clomiphene citrate treated men (19.6 vs 9.2 months). For testosterone replacement therapy and clomiphene citrate the mean change in hematocrit was 3.0% and 0.6%, and the mean change in serum testosterone was 333.1 and 367.6 ng/dl, respectively. The prevalence of polycythemia in men on testosterone replacement was 11.2% vs 1.7% in men on clomiphene citrate (p = 0.0003). This significance remained on logistic regression after correcting for age, site, smoking history and pretreatment hematocrit. The prevalence of polycythemia in men treated with clomiphene citrate was markedly lower than that in men on testosterone replacement therapy. The improvement in absolute serum testosterone levels was similar to that in men on testosterone replacement. There is no significant risk of polycythemia in men treated with clomiphene citrate for hypogonadism. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Citrate biodegradation. Mid-year status report, [January 1994--June 1994

International Nuclear Information System (INIS)

Francis, A.J.; Dodge, C.J.; Chatterjee, S.; Landry, M.F.

1994-07-01

The Uranium Soils Integrated Demonstration (USID) Program was established to demonstrate advanced technologies for the remediation of uranium contaminated soils. This program, managed by the Fernald Environmental Restoration Management Corporation (FERMCO), focuses on the development and demonstration of new soil remediation processes which are faster, safer, and more economical for use at the Fernald site and throughout the DOE complex for cleanup of similar contaminants. Brookhaven National Laboratory (BNL) has developed a process which uses citric acid to treat contaminated soils and wastes with the subsequent recovery of toxic metals and uranium. Citric acid, a naturally occurring organic chelating agent, forms multidentate stable complexes with the transition metals and actinides, and has been effectively used to extract uranium and other metals from solid wastes via the formation of soluble metal citrate complexes. Further studies have also shown that several of the metal citrate complexes are readily biodegraded by microorganisms. During this process, the metals form a precipitate or become associated with the biomass and are recovered at the end of the biodegradation. Although uranyl citrate is recalcitrant to biodegradation, upon exposure to visible light it undergoes photochemical degradation resulting in the formation of an insoluble, stable polymeric form of uranium

PCAF/GCN5-Mediated Acetylation of RPA1 Promotes Nucleotide Excision Repair

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Meimei Zhao

2017-08-01

Full Text Available The RPA complex can integrate multiple stress signals into diverse responses by activating distinct DNA repair pathways. However, it remains unclear how RPA1 elects to activate a specific repair pathway during different types of DNA damage. Here, we report that PCAF/GCN5-mediated K163 acetylation of RPA1 is crucial for nucleotide excision repair (NER but is dispensable for other DNA repair pathways. Mechanistically, we demonstrate that the acetylation of RPA1 is critical for the steady accumulation of XPA at damaged DNA sites and preferentially activates the NER pathway. DNA-PK phosphorylates and activates PCAF upon UV damage and consequently promotes the acetylation of RPA1. Moreover, the acetylation of RPA1 is tightly regulated by HDAC6 and SIRT1. Together, our results demonstrate that the K163 acetylation of RPA1 plays a key role in the repair of UV-induced DNA damage and reveal how the specific RPA1 modification modulates the choice of distinct DNA repair pathways.

Comparison of 2-Octanol and Tributyl Phosphate in Recovery of Tungsten from Sulfuric-Phosphoric Acid Leach Solution of Scheelite

Science.gov (United States)

Liao, Yulong; Zhao, Zhongwei

2018-04-01

Tungsten was recovered from sulfuric-phosphoric acid leach solution of scheelite using 2-octanol and tributyl phosphate (TBP). Approximately 76% of the tungsten and less than 6.2% of the iron were extracted when using 70% 2-octanol, showing good selectivity for tungsten over iron; the tungsten extraction could not be significantly enhanced using a three-stage countercurrent simulation test. Moreover, more than 99.2% of the W and 91.0% of the Fe were extracted when using 70% TBP, showing poor selectivity, but after pretreating the leach solution with iron powder, less than 5.5% of the Fe was extracted. The loaded phases were stripped using deionized water and ammonia solution. The maximum stripping rate of tungsten from loaded 2-octanol was 45.6% when using water, compared with only 13.1% from loaded TBP. Tungsten was efficiently stripped from loaded phases using ammonia solution without formation of Fe(OH)3 precipitate. Finally, a flow sheet for recovery of tungsten with TBP is proposed.

N-acetyl Aspartate Levels in Adolescents With Bipolar and/or Cannabis Use Disorders

Science.gov (United States)

Bitter, Samantha M.; Weber, Wade A.; Chu, Wen-Jang; Adler, Caleb M.; Eliassen, James C.; Strakowski, Stephen M.; DelBello, Melissa P.

2014-01-01

Objective Bipolar and cannabis use disorders commonly co-occur during adolescence, and neurochemical studies may help clarify the pathophysiology underlying this co-occurrence. This study compared metabolite concentrations in the left ventral lateral prefrontal cortex among: adolescents with bipolar disorder (bipolar group; n=14), adolescents with a cannabis use disorder (cannabis use group, n=13), adolescents with cannabis use and bipolar disorders (bipolar and cannabis group, n=25), and healthy adolescents (healthy controls, n=15). We hypothesized that adolescents with bipolar disorder (with or without cannabis use disorder) would have decreased N-acetyl aspartate levels in the ventral lateral prefrontal cortex compared to the other groups, and that the bipolar and cannabis group would have the lowest N-acetyl aspartate levels of all groups. Methods N-acetyl aspartate concentrations in the left ventral lateral prefrontal cortex were obtained using Proton Magnetic Resonance Spectroscopy. Results Adolescents with bipolar disorder showed significantly lower left ventral lateral prefrontal cortex N-acetyl aspartate levels, but post-hoc analyses indicated that this was primarily due to increased N-acetyl aspartate levels in the cannabis group. The cannabis use disorder group had significantly higher N-acetyl aspartate levels compared to the bipolar disorder and the bipolar and cannabis groups (p=0.0002 and p=0.0002, respectively). Pearson correlations revealed a significant positive correlation between amount of cannabis used and N-acetyl aspartate concentrations. Conclusions Adolescents with cannabis use disorder showed higher levels of N-acetyl aspartate concentrations that were significantly positively associated with the amount of cannabis used; however, this finding was not present in adolescents with comorbid bipolar disorder. PMID:24729763

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

Science.gov (United States)

2013-06-10

... citric acid and citrate salts from the People's Republic of China for the period January 1, 2011, through... and Certain Citrate Salts from the People's Republic of China: Notice of Countervailing Duty Order, 74... subsidy, i.e., a government-provided financial contribution that gives rise to a benefit to the recipient...

Neptunium speciation (complexation and redox behaviour) in aqueous citrate medium

International Nuclear Information System (INIS)

Bonin, L.; Ansoborlo, E.; Moisy, Ph.

2005-01-01

Full text of publication follows: In the framework of the French Environmental Nuclear Toxicology programme, additional experiments related to the decorporation of actinides are planned. The lack of information on the neptunium behaviour within blood and the inefficiency of therapeutic treatments, led us to study the complexation of this element with basic anions. Within this purpose, the in vitro behaviour of Np IV and Np V in simple media simulating biological media was studied: blood plasma is one of the media of interest and it can be simulated, from a chemical point of view, by an aqueous solution with pH 7.4, containing ions such as citrate (1.6 10 -4 mol/L), lactate (1.5 10 -3 mol/L), CO 3 2- (2.5 10 -2 mol/L), PO 4 3- (1.1 10 -3 mol/L), SO 4 2- (3.3 10 -4 mol/L) and Cl - (9 10 -2 mol/L). This study was more specifically focused on the behaviour of neptunium with citrate ion, which is also a basic ligand to consider when one wishes to study the migration of actinides in the environment, since it exists in significant amounts in the ground due to its production by the plants. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np V with various acid-basic forms of the citrate anion was observed; regarding Np IV , two complexes, with 1:1 and 1:2 stoichiometry, have been respectively observed. The reactivity of Np VI is probably similar to the behaviour of U VI , which is reported in literature to form a complex with a 1:1 stoichiometry with the Cit 3- anion From the quantitative study of these equilibria, it has been possible to determine the values of various equilibrium constants. Concerning the stability of neptunium towards oxido-reduction, it was confirmed that Np VI was very quickly reduced to Np V by the citrate anions, whereas Np IV was stable. In the case of Np V , it was observed that, depending on the pH and the citrate

Histone Deacetylase 1 Plays an Acetylation-Independent Role in Influenza A Virus Replication

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Lin Chen

2017-12-01

Full Text Available Influenza A viruses (IAVs take advantage of the host acetylation system for their own benefit. Whether the nucleoprotein (NP of IAVs undergoes acetylation and the interaction between the NP and the class I histone deacetylases (HDACs were largely unknown. Here, we showed that the NP protein of IAV interacted with HDAC1, which downregulated the acetylation level of NP. Using mass spectrometry, we identified lysine 103 as an acetylation site of the NP. Compared with wild-type protein, two K103 NP mutants, K103A and K103R, enhanced replication efficiency of the recombinant viruses in vitro. We further demonstrated that HDAC1 facilitated viral replication via two paths: promoting the nuclear retention of NP and inhibiting TBK1-IRF3 pathway. Our results lead to a new mechanism for regulating NP acetylation, indicating that HDAC1 may be a possible target for antiviral drugs.

Crystal structure of tabtoxin resistance protein complexed with acetyl coenzyme A reveals the mechanism for beta-lactam acetylation.

Science.gov (United States)

He, Hongzhen; Ding, Yi; Bartlam, Mark; Sun, Fei; Le, Yi; Qin, Xincheng; Tang, Hong; Zhang, Rongguang; Joachimiak, Andrzej; Liu, Jinyuan; Zhao, Nanming; Rao, Zihe

2003-01-31

Tabtoxin resistance protein (TTR) is an enzyme that renders tabtoxin-producing pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. Here, we report the crystal structure of TTR complexed with its natural cofactor, acetyl coenzyme A (AcCoA), to 1.55A resolution. The binary complex forms a characteristic "V" shape for substrate binding and contains the four motifs conserved in the GCN5-related N-acetyltransferase (GNAT) superfamily, which also includes the histone acetyltransferases (HATs). A single-step mechanism is proposed to explain the function of three conserved residues, Glu92, Asp130 and Tyr141, in catalyzing the acetyl group transfer to its substrate. We also report that TTR possesses HAT activity and suggest an evolutionary relationship between TTR and other GNAT members.

Bright luminescence of Vibrio fischeri aconitase mutants reveals a connection between citrate and the Gac/Csr regulatory system.

Science.gov (United States)

Septer, Alecia N; Bose, Jeffrey L; Lipzen, Anna; Martin, Joel; Whistler, Cheryl; Stabb, Eric V

2015-01-01

The Gac/Csr regulatory system is conserved throughout the γ-proteobacteria and controls key pathways in central carbon metabolism, quorum sensing, biofilm formation and virulence in important plant and animal pathogens. Here we show that elevated intracellular citrate levels in a Vibrio fischeri aconitase mutant correlate with activation of the Gac/Csr cascade and induction of bright luminescence. Spontaneous or directed mutations in the gene that encodes citrate synthase reversed the bright luminescence of aconitase mutants, eliminated their citrate accumulation and reversed their elevated expression of CsrB. Our data elucidate a correlative link between central metabolic and regulatory pathways, and they suggest that the Gac system senses a blockage at the aconitase step of the tricarboxylic acid cycle, either through elevated citrate levels or a secondary metabolic effect of citrate accumulation, and responds by modulating carbon flow and various functions associated with host colonization, including bioluminescence. © 2014 John Wiley & Sons Ltd.

Kinetic and Thermodynamic Analysis of Acetyl-CoA Activation of Staphylococcus aureus Pyruvate Carboxylase.

Science.gov (United States)

Westerhold, Lauren E; Bridges, Lance C; Shaikh, Saame Raza; Zeczycki, Tonya N

2017-07-11

Allosteric regulation of pyruvate carboxylase (PC) activity is pivotal to maintaining metabolic homeostasis. In contrast, dysregulated PC activity contributes to the pathogenesis of numerous diseases, rendering PC a possible target for allosteric therapeutic development. Recent research efforts have focused on demarcating the role of acetyl-CoA, one of the most potent activators of PC, in coordinating catalytic events within the multifunctional enzyme. Herein, we report a kinetic and thermodynamic analysis of acetyl-CoA activation of the Staphylococcus aureus PC (SaPC)-catalyzed carboxylation of pyruvate to identify novel means by which acetyl-CoA synchronizes catalytic events within the PC tetramer. Kinetic and linked-function analysis, or thermodynamic linkage analysis, indicates that the substrates of the biotin carboxylase and carboxyl transferase domain are energetically coupled in the presence of acetyl-CoA. In contrast, both kinetic and energetic coupling between the two domains is lost in the absence of acetyl-CoA, suggesting a functional role for acetyl-CoA in facilitating the long-range transmission of substrate-induced conformational changes within the PC tetramer. Interestingly, thermodynamic activation parameters for the SaPC-catalyzed carboxylation of pyruvate are largely independent of acetyl-CoA. Our results also reveal the possibility that global conformational changes give rise to observed species-specific thermodynamic activation parameters. Taken together, our kinetic and thermodynamic results provide a possible allosteric mechanism by which acetyl-CoA coordinates catalysis within the PC tetramer.

Is magnesium citrate treatment effective on pain, clinical parameters and functional status in patients with fibromyalgia?

Science.gov (United States)

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.

Transport and metabolism of indole-3-acetyl-myo-inositol-galactoside in seedlings of Zea mays

Science.gov (United States)

Komoszynski, M.; Bandurski, R. S.

1986-01-01

Indole-3-acetyl-myo-inositol galactoside labeled with 3H in the indole and 14C in the galactose moieties was applied to kernels of 5 day old germinating seedlings of Zea mays. Indole-3-acetyl-myo-inositol galactoside was not transported into either the shoot or root tissue as the intact molecule but was instead hydrolyzed to yield [3H]indole-3-acetyl-myo-inositol and [3H]indole-3-acetic acid which were then transported to the shoot with little radioactivity going to the root. With certain assumption concerning the equilibration of applied [3H]indole-3-acetyl-myo-inositol-[U-14C]galactose with the endogenous pool, it may be concluded that indole-3-acetyl-myo-inositol galactoside in the endosperm supplies about 2 picomoles per plant per hour of indole-3-acetyl-myo-inositol and 1 picomole per plant per hour of indole-3-acetic acid to the shoot and thus is comparable to indole-3-acetyl-myo-inositol as a source of indole-acetic acid for the shoot. Quantitative estimates of the amount of galactose in the kernels suggest that [3H]indole-3-acetyl-myo-inositol-[14C]galactose is hydrolyzed after the compound leaves the endosperm but before it reaches the shoot. In addition, [3H]indole-3-acetyl-myo-inositol-[14C]galactose supplies appreciable amounts of 14C to the shoot and both 14C and 3H to an uncharacterized insoluble fraction of the endosperm.

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

Science.gov (United States)

2011-06-10

... DEPARTMENT OF COMMERCE International Trade Administration [A-122-853] Citric Acid and Certain... the antidumping duty order on citric acid and certain citrate salts (citric acid) from Canada. The... order on citric acid from Canada. See Citric Acid and Certain Citrate Salts From Canada: Preliminary...

Acute effect of citrate bath on postdialysis alkalaemia

Directory of Open Access Journals (Sweden)

Patricia De Sequera Ortiz

2015-03-01

Conclusion: Dialysis with citrate provides better control of postdialysis acid-base balance, decreases/avoids postdialysis alkalaemia, and lowers the increase in Cac and Cai. This finding is of special interest in patients with predisposing factors for arrhythmia and patients with respiratory failure, carbon dioxide retention, calcifications and advanced liver disease.

Developmental toxicity of orally administered sildenafil citrate (Viagra) in SWR/J mice.

Science.gov (United States)

Abou-Tarboush, Faisal Mohamed; Abdel-Samad, Mohamed Fathy; Al-Meteri, Mokhlid Hamed

2011-04-01

Normal adult inbred SWR/J mice were used to investigate the teratogenic and other possible toxic effects of various dose levels of sildenafil citrate (Viagra) on fetuses. Multiple dose levels of 6.5, 13.0, 19.5, 26.0, 32.5 or 40.0 mg of sildenafil citrate/kg body weight (which correspond to the multiples of 1, 2, 3, 4, 5 or 6 of human 50 mg Viagra, respectively) were orally administered into pregnant mice on days 7-9, 10-12 or 13-15 of gestation. On day 17 of pregnancy, all fetuses were removed and examined for toxic phenomena (embryo-fetal toxicity) and for external, internal and skeletal malformations. A total of 285 pregnant mice were used in the present study. None of the dams treated with sildenafil citrate at any of the oral dose levels used in the present study died during the experimental period and all dams treated with the drug failed to reveal overt signs of maternal toxicity. Moreover, the results of the present study clearly demonstrate that none of the multiple oral dose levels of the drug at any time interval used has induced any external, internal or skeletal malformations in the fetuses obtained from treated females. However, the dose level of 40 mg/kg body weight of sildenafil citrate has a growth suppressing effect on alive fetuses when it was administered at all the time intervals used in the present study. Furthermore, the dose levels 26.0, 32.5 and 40 mg/kg of the drug have embryo-fetal toxicity when the drug is applied on days 13-15 of gestation. The possible mechanisms involved in the embryo-fetal toxicity and fetal growth suppressing effects of sildenafil citrate were discussed. The results of this study have important implications for the widespread use of this drug.

The Effect of Polymer Molecular Weight on Citrate Crosslinked ...

African Journals Online (AJOL)

SEM), dissolution studies and differential scanning calorimetry (DSC) for surface ... Conclusion: The citrate-crosslinked chitosan films can be modulated to vary swelling and drug release at pH 3.5 and 6.2; this feature makes them useful tools for ...

An excess of topical calcium and magnesium reverses the therapeutic effect of citrate on the development of corneal ulcers after alkali injury.

Science.gov (United States)

Haddox, J L; Pfister, R R; Slaughter, S E

1996-03-01

Our purpose was to determine whether chelation of Ca2+ and Mg2+ is the mechanism by which sodium citrate inhibits corneal ulceration in the alkali-injured rabbit eye. The right eyes of 60 albino rabbits (2-2.5 kg) were alkali-injured by filling a 12-mm-diameter plastic well placed on the corneal surface with 0.4 ml of 1 N NaOH. After 35 s the alkali was aspirated, and the well was rinsed with physiological saline. Animals were randomly distributed to three treatment groups of equal size. Two drops of the following topical medications were administered on the hour (14 times per day) for 35 days: physiological saline, 10% citrate in saline, and 346 mM Ca2+, 346 mM Mg2+, and 10% citrate in saline. During the experiment, significantly fewer ulcerations occurred in the citrate-treated eyes (five of 20, 25%) than in the saline-treated eyes (13 of 20, 65%) or in the calcium-magnesium-citrate-treated eyes (15 of 20, 75%). When ulcerations did develop in the citrate group, they occurred significantly later and were less severe than those in the saline and calcium-magnesium-citrate groups. There was a significant increase in the number of eyes with signs of band keratopathy and translucent areas in the calcium-magnesium-citrate group when compared with the other two groups. As in previous studies, sodium citrate significantly inhibited the development of corneal ulcers after alkali injury. The annullment of the favorable effect of citrate on ulceration in the alkali-injured eye by the addition of calcium and magnesium shows that the mechanism of action of citrate is the chelation of these divalent cations.

Adherence rates to ferric citrate as compared to active control in patients with end stage kidney disease on dialysis.

Science.gov (United States)

Jalal, Diana; McFadden, Molly; Dwyer, Jamie P; Umanath, Kausik; Aguilar, Erwin; Yagil, Yoram; Greco, Barbara; Sika, Mohammed; Lewis, Julia B; Greene, Tom; Goral, Simin

2017-04-01

Oral phosphate binders are the main stay of treatment of hyperphosphatemia. Adherence rates to ferric citrate, a recently approved phosphate binder, are unknown. We conducted a post-hoc analysis to evaluate whether adherence rates were different for ferric citrate vs. active control in 412 subjects with end stage kidney disease (ESKD) who were randomized to ferric citrate vs. active control (sevelamer carbonate and/or calcium acetate). Adherence was defined as percent of actual number of pills taken to total number of pills prescribed. There were no significant differences in baseline characteristics including gender, race/ethnicity, and age between the ferric citrate and active control groups. Baseline phosphorus, calcium, and parathyroid hormone levels were similar. Mean (SD) adherence was 81.4% (17.4) and 81.7% (15.9) in the ferric citrate and active control groups, respectively (P = 0.88). Adherence remained similar between both groups after adjusting for gender, race/ethnicity, age, cardiovascular disease (CVD), and diabetic nephropathy (mean [95% CI]: 81.4% [78.2, 84.6] and 81.5% [77.7, 85.2] for ferric citrate and active control, respectively). Gender, race/ethnicity, age, and diagnosis of diabetic nephropathy did not influence adherence to the prescribed phosphate binder. Subjects with CVD had lower adherence rates to phosphate binder; this was significant only in the active control group. Adherence rates to the phosphate binder, ferric citrate, were similar to adherence rates to active control. Similar adherence rates to ferric citrate are notable since tolerance to active control was an entry criteria and the study was open label. Gender, race/ethnicity, nor age influenced adherence. © 2016 International Society for Hemodialysis.

Identification and purification of O-acetyl-L-serine sulphhydrylase in Penicillium chrysogenum

DEFF Research Database (Denmark)

østergaard, Simon; Theilgaard, Hanne Birgitte; Nielsen, Jens Bredal

1998-01-01

We have demonstrated that Penicillium chrysogenum possesses the L-cysteine biosynthetic enzyme O-acetyI-L-serine sulphhydrylase (EC 4.2.99.8) of the direct sulphhydrylation pathway. The finding of this enzyme, and thus the presence of the direct sulphhydrylation pathway in P. chrysogenum, creates...... the potential for increasing the overall yield in penicillin production by enhancing the enzymatic activity of this microorganism. Only O-acetyl-L-serine sulphhydrylase and O-acetyl-L-homoserine sulphhydrylase (EC 4.2.99.10) have been demonstrated to use O-acetyl-L-serine as substrate for the formation of L-cysteine....... The purified enzyme did not catalyse the formation of L-homocysteine from O-acetyl-L-homoserine and sulphide, excluding the possibility that the purified enzyme was O-acetyI-L-homoserine sulphhydrylase with multiple substrate specificity. The purification enhanced the enzymatic specific activity 93-fold...

Beliefs and social norms about sildenafil citrate (Viagra) misuse and perceived consequences among Houstonian teenage males.

Science.gov (United States)

Peters, Ronald J; Johnson, Regina J; Kelder, Steve; Meshack, Angela F; Jefferson, Troy

2007-09-01

In the current study, a qualitative approach was used to investigate relevant beliefs and norms associated with sildenafil citrate (Viagra) consumption, initiation, and perceived consequences. Focus groups were conducted with 43 young men aged 18 and 19 years who identified themselves as lifetime sildenafil citrate users. The majority of focus group participants believed that "curiosity" and "peer pressure" contributed to their initial use. Most revealed that they first heard about sildenafil citrate from television advertisements, family members, friends, or sporting events, and they were able to obtain the drug from their friends and family members or they stole it from their father or grandfather. These findings may highlight the relative importance of exposure to prescription drug messages among those to whom the message is not specifically targeted, that is, young men. It is possible that the sildenafil citrate television messages are recalled by not only older male audiences but also by teenagers and younger men, producing similar cognitive processing and curiosity in both age cohorts.

Potassium citrate prevents increased osteoclastogenesis resulting from acidic conditions: Implication for the treatment of postmenopausal bone loss.

Directory of Open Access Journals (Sweden)

Donatella Granchi

Full Text Available The extracellular acidic milieu in bones results in activation of osteoclasts (OC and inhibition of osteoblasts (OB causing a net loss of calcium from the skeleton and the deterioration of bone microarchitecture. Alkalinization through supplementation with potassium citrate (K citrate has been proposed to limit the osteopenia progression, even though its pharmacological activity in bone microenvironment is not well defined. We evaluated if K citrate was able to prevent the adverse effects that acidic milieu induces on bone cells. OC and OB were maintained in neutral (pH 7.4 versus acidic (pH 6.9 culture medium, and treated with different K citrate concentrations. We evaluated the OC differentiation at seven days, by counting of multinucleated cells expressing tartrate-resistant acid phosphatase, and the activity of mature OC at 14 days, by quantifying of collagen degradation. To evaluate the effects on OB, we analyzed proliferation, mineralization, and expression of bone-related genes. We found that the low pH increased OC differentiation and activity and decreased OB function. The osteoclastogenesis was also promoted by RANKL concentrations ineffective at pH 7.4. Non-cytotoxic K citrate concentrations were not sufficient to steadily neutralize the acidic medium, but a inhibited the osteoclastogenesis, the collagen degradation, and the expression of genes involved in RANKL-mediated OC differentiation, b enhanced OB proliferation and alkaline phosphatase expression, whereas it did not affect the in vitro mineralization, and c were effective also in OC cultures resistant to alendronate, i.e. the positive control of osteoclastogenesis inhibition. In conclusion, K citrate prevents the increase in OC activity induced by the acidic microenvironment, and the effect does not depend exclusively on its alkalizing capacity. These data provide the biological basis for the use of K citrate in preventing the osteopenia progression resulting from low

Crystal structure of tabtoxin resistance protein complexed with acetyl coenzyme A reveals the mechanism for {beta}-lactam acetylation.

Energy Technology Data Exchange (ETDEWEB)

He, H.; Ding, Y.; Bartlam, M.; Sun, F.; Le, Y.; Qin, X.; Tang, H.; Zhang, R.; Joachimiak, A.; Liu, J.; Zhao, N.; Rao, Z.; Biosciences Division; Tsinghua Univ.; Chinese Academy of Science

2003-01-31

Tabtoxin resistance protein (TTR) is an enzyme that renders tabtoxin-producing pathogens, such as Pseudomonas syringae, tolerant to their own phytotoxins. Here, we report the crystal structure of TTR complexed with its natural cofactor, acetyl coenzyme A (AcCoA), to 1.55 {angstrom} resolution. The binary complex forms a characteristic 'V' shape for substrate binding and contains the four motifs conserved in the GCN5-related N-acetyltransferase (GNAT) superfamily, which also includes the histone acetyltransferases (HATs). A single-step mechanism is proposed to explain the function of three conserved residues, Glu92, Asp130 and Tyr141, in catalyzing the acetyl group transfer to its substrate. We also report that TTR possesses HAT activity and suggest an evolutionary relationship between TTR and other GNAT members.

Effect of acetylation on monoclonal antibody ZCE-025 Fab': Distribution in normal and tumor-bearing mice

International Nuclear Information System (INIS)

Tarburton, J.P.; Halpern, S.E.; Hagan, P.L.; Sudora, E.; Chen, A.; Fridman, D.M.; Pfaff, A.E.

1990-01-01

Studies were performed to determine in vitro and in vivo effects of acetylation on Fab' fragments of ZCE-025, a monoclonal anti-CEA antibody. Isoelectric focusing revealed a drop in isoelectric point of 1.7 pI units following acetylation. Biodistribution studies of acetylated and nonacetylated [111In]Fab' were performed in normal BALB/c mice and in nude mice bearing the T-380 CEA-producing human colon tumor. The acetylated fragments remained in the vascular compartment longer and had significantly diminished renal uptake of 111In compared to controls. While acetylation itself effected a 50% drop in immunoreactivity, tumor uptake of the acetylated and nonacetylated 111In-labeled Fab' fragments was comparable, with the exception of one data point, through 72 h

Biodegradation of tributyl phosphate by granular biofilms

International Nuclear Information System (INIS)

Joshi, Hiren M.; Nancharaiah, Y.V.; Venugopalan, V.P.

2009-01-01

Full text: Tributyl phosphate (TBP) is used as plasticizer for cellulose esters, lacquers, plastic and vinyl resins and as a solvent extractant of rare earth metals. In nuclear power industry, it is used as a solvent for the extraction of uranium and plutonium salts during fuel reprocessing. TBP does not occur naturally in the environment. It is sparingly soluble in water and once released into soil or aquatic systems, is only moderately biodegradable. There are many proposed mechanisms for TBP biodegradation, which involve stepwise enzymatic hydrolysis to orthophosphate and n-butanol and mono-oxygenase based transformation and then degradation. Microbial processes involving multispecies consortia offer better choice over monoculture processes for degradation of complex wastes. Processes based on immobilized microbial consortia are characterized by significantly reduced settling time, high stability in presence of varying organic load, effective mineralization and amenability to bioaugmentation, which make them a good choice for bioremediation and waste water treatment. The objective of this study was to investigate the suitability of aerobic microbial granules (also known as granular biofilms) for efficient biodegradation of TBP. For this purpose, we set up 4 litre cylindrical sequencing batch reactors (SBR) in triplicates and inoculated them with sludge (mean sludge size ∼ 60 mm) obtained from an operating wastewater treatment plant. The SBRs were operated on a 6h cycle with 66% volumetric exchange ratio. The reactors were fed with synthetic waste water along with 90 mM acetate and 0.5 mM TBP. The concentration of TBP was slowly raised to 2mM. After 3 months of operation, microbial granules (mean size: 2.05 mm) capable of TBP degradation were observed in the reactors. Gas chromatographic analysis of samples showed that after 6h of operational cycle 2 mM initial concentration of TBP was reduced to 0.2 mM, after which there was no further degradation. Cessation

Effects of heating atmosphere on formation of crystalline citrate-derived LaAlO3 nanoparticles

International Nuclear Information System (INIS)

Yu, Hsuan-Fu; Guo, Yu-Man

2011-01-01

Research highlights: → LaAlO 3 can be crystallized at 550 deg. C in an oxygen-enriched atmosphere. → Calcining the citrate precursor in oxygen atmosphere lowers the reaction temperatures to form crystalline LaAlO 3 . → In oxygen atmosphere, pure citrate-derived LaAlO 3 nanoparticles can be produced at 700 deg. C. - Abstract: Crystalline LaAlO 3 nanoparticles were synthesized at relative low temperatures, using a citrate-precursor technique. La(NO 3 ) 3 , Al(NO 3 ) 3 , and C 3 H 4 (OH)(COOH) 3 , in a molar ratio of 1:1:1, were dissolved in deionized water. NH 4 OH was used to adjust the aqueous solution to pH 7. After drying, the citrate precursors were charred at 350 deg. C, followed by calcination at different temperatures, in air or oxygen atmosphere. The thermochemical properties of the resultant particles were analyzed using thermogravimetric and differential thermal analysis, X-ray diffractometry, infrared spectroscopy, scanning electron microscopy, and transmission electron microscopy. Effects of calcination temperature and heating atmosphere on the formation of crystalline LaAlO 3 nanoparticles were investigated. In O 2 atmosphere, clacining the citrate-derived charred solid precursor at 700 deg. C for 3 h can decompose all intermediates to produce pure LaAlO 3 nanoparticles (particle sizes ≤ 100 nm) with an average crystallite size of about 24 nm and possessing high sinterability.

Evaluation of hilar 67Ga-citrate uptake in bronchogenic carcinoma

International Nuclear Information System (INIS)

Matsuno, Noriyo; Kuyama, Junpei; Uchida, Yoshitaka; Hatano, Osamu; Imai, Yasunori; Uno, Kimiichi; Minoshima, Satoshi.

1995-01-01

We evaluated hilar uptake on 67 Ga-citrate scintigraphy and correlated with hilar lymph node metastases in one-hundred seventeen cases (two-hundred thirty four hila) of bronchogenic carcinoma. Hilar uptake was classified into three grades independently on anterior and posterior chest views: no uptake (grade 0), uptake equal to that in the thoracic vertebrae (grade 1), and uptake higher than that in the thoracic vertebrae (grade 2). If a summed grade of anterior and posterior view was larger than 3, hilar uptake was considered as positive. In forty-four cases (forty-nine hila) with hilar lymph node metastases, positive hilar uptake was found in ten cases (eleven hila), resulting in sensitivity of 22% based on cases and 23% based on hila. In seventy-three cases (one-hundred forty-six hila) without hilar lymph node metastases, positive hilar uptake was found in six cases (ten hila), resulting in specificity of 91% based on cases and 93% based on hila. In comparison to scintigraphic findings of unilaterally positive hilar uptake, findings of bilaterally positive hilar uptake showed significantly lower accuracy in determining presence of hilar lymph node metastases. No definite correlation between hilar uptake and histopathology or 67 Ga-citrate uptake in a primary tumor was observed. The results indicate that usefulness of 67 Ga-citrate scintigraphy is limited when evaluating hilar lymph node metastases in bronchogenic carcinoma. (author)

Dynamics of meso and thermo citrate synthases with implicit solvation

Science.gov (United States)

Cordeiro, J. M. M.

The dynamics of hydration of meso and thermo citrate synthases has been investigated using the EEF1 methodology implemented with the CHARMM program. The native enzymes are composed of two identical subunits, each divided into a small and large domain. The dynamics behavior of both enzymes at 30°C and 60°C has been compared. The results of simulations show that during the hydration process, each subunit follows a different pathway of hydration, in spite of the identical sequence. The hydrated structures were compared with the crystalline structure, and the root mean square deviation (RMSD) of each residue along the trajectory was calculated. The regions with larger and smaller mobility were identified. In particular, helices belonging to the small domain are more mobile than those of the large domain. In contrast, the residues that constitute the active site show a much lower displacement compared with the crystalline structure. Hydration free energy calculations point out that Thermoplasma acidophilum citrate synthase (TCS) is more stable than chicken citrate synthase (CCS), at high temperatures. Such result has been ascribed to the higher number of superficial charges in the thermophilic homologue, which stabilizes the enzyme, while the mesophilic homologue denatures. These results are in accord with the experimental found that TCS keeps activity at temperatures farther apart from the catalysis regular temperature than the CCS.

Transport and metabolism of indole-3-acetyl-myo-inositol-galactoside in seedlings of Zea mays

International Nuclear Information System (INIS)

Komoszynski, M.; Bandurski, R.S.

1986-01-01

Indole-3-acetyl-myo-inositol galactoside labeled with 3 H in the indole and 14 C in the galactose moieties was applied to kernels of 5 day old germinating seedlings of Zea mays. Indole-3-acetyl-myo-inositol galactoside was not transported into either the shoot or root tissue as the intact molecule but was instead hydrolyzed to yield [ 3 H]indole-3-acetyl-myo-inositol and [ 3 H]indole-3-acetic acid which were then transported to the shoot with little radioactivity going to the root. With certain assumptions concerning the equilibration of applied [ 3 H]indole-3-acetyl-myo-inositol-[U- 14 C]galactose with the endogenous pool, it may be concluded that indole-3-acetyl-myo-inositol galactoside in the endosperm supplies about 2 picomoles per plant per hour of indole-3-acetic acid to the shoot and thus is comparable to indole-3-acetyl-myo-inositol as a source of indoleacetic acid for the shoot. Quantitative estimates of the amount of galactose in the kernels suggest that [ 3 H]indole-3-acetyl-myo-inositol-[ 14 C] galactose is hydrolyzed after the compound leaves the endosperm but before it reaches the shoot. In addition, [ 3 H]indole-3-acetyl-myo-inositol-[ 14 C]galactose supplies appreciable amounts of 14 C to the shoot and both 14 C and 3 H to an uncharacterized insoluble fraction of the endosperm

Enhanced citrate production through gene insertion in Aspergillus niger

DEFF Research Database (Denmark)

Jongh, Wian de; Nielsen, Jens

2007-01-01

The effect of inserting genes involved in the reductive branch of the tricarboxylic acid (TCA) cycle on citrate production by Aspergillus niger was evaluated. Several different genes were inserted individually and in combination, i.e. malate dehydrogenase (mdh2) from Saccharomyces cerevisiae, two...

Ovarian capsular drilling in the treatment of clomiphene citrate ...

African Journals Online (AJOL)

Background: Laparoscopic Ovarian Drilling (LOD) is an effective and a well evaluated surgical Treatment of Clomiphene Citrate resistant Polycystic ovarian syndrome. Transvaginal hydrolaparoscopy (TVHL) is a relatively new simple method of exploring the pelvis and has recently been introduced as a transvaginal ...

Fragrance material review on acetyl cedrene.

Science.gov (United States)

Scognamiglio, J; Letizia, C S; Politano, V T; Api, A M

2013-12-01

A toxicologic and dermatologic review of acetyl cedrene when used as a fragrance ingredient is presented. Acetyl cedrene is a member of the fragrance structural group Alkyl Cyclic Ketones. The generic formula for this group can be represented as (R1)(R2)CO. These fragrances can be described as being composed of an alkyl, R1, and various substituted and bicyclic saturated or unsaturated cyclic hydrocarbons, R2, in which one of the rings may include up to 12 carbons. Alternatively, R2 may be a carbon bridge of C2-C4 carbon chain length between the ketone and cyclic hydrocarbon. This review contains a detailed summary of all available toxicology and dermatology papers that are related to this individual fragrance ingredient and is not intended as a stand-alone document. Available data for acetyl cedrene were evaluated then summarized and includes physical properties, acute toxicity, skin irritation, mucous membrane (eye) irritation, skin sensitization, elicitation, phototoxicity, photoallergy, toxicokinetics, repeated dose, reproductive toxicity, and genotoxicity data. A safety assessment of the entire Alkyl Cyclic Ketones will be published simultaneously with this document; please refer to Belsito et al. (2013) (Belsito, D., Bickers, D., Bruze, M., Calow, P., Dagli, M., Fryer, A.D., Greim, H., Miyachi, Y., Saurat, J.H., Sipes, I.G., 2013. A Toxicologic and Dermatologic Assessment of Alkyl Cyclic Ketones When Used as Fragrance Ingredients. Submitted with this manuscript.) for an overall assessment of the safe use of this material and all Alkyl Cyclic Ketones in fragrances. Copyright © 2013. Published by Elsevier Ltd.

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

Science.gov (United States)

2013-06-07

... DEPARTMENT OF COMMERCE International Trade Administration [A-122-853] Citric Acid and Certain... on citric acid and certain citrate salts (citric acid) from Canada. The period of review (POR) is May... INFORMATION: Scope of the Order The merchandise covered by this order is citric acid and certain citrate salts...

Pyrolytic citrate synthesis and ozone annealing

International Nuclear Information System (INIS)

Celani, F.; Saggese, A.; Giovannella, C.; Messi, R.; Merlo, V.

1988-01-01

A pyrolytic procedure is described that via a citrate synthesis allowed us to obtain very fine grained YBCO powders that, after a first furnace thermal treatment in ozone, results already to contain a large amount of superconducting microcrystals. A second identical thermal treatment gives a final product strongly textured, as shown by magnetic torque measurements. Complementary structural and diamagnetic measurement show the high quality of these sintered pellets. The role covered by both the pyrolytic preparation and the ozone annealing are discussed

Lifespan extension and increased resistance to environmental stressors by N-Acetyl-L-Cysteine in Caenorhabditis elegans

Directory of Open Access Journals (Sweden)

Seung-Il Oh

2015-05-01

Full Text Available OBJECTIVE: This study was performed to determine the effect of N-acetyl-L-cysteine, a modified sulfur-containing amino acid that acts as a strong cellular antioxidant, on the response to environmental stressors and on aging in C. elegans. METHOD: The survival of worms under oxidative stress conditions induced by paraquat was evaluated with and without in vivo N-acetyl-L-cysteine treatment. The effect of N-acetyl-L-cysteine on the response to other environmental stressors, including heat stress and ultraviolet irradiation (UV, was also monitored. To investigate the effect on aging, we examined changes in lifespan, fertility, and expression of age-related biomarkers in C. elegans after N-acetyl-L-cysteine treatment. RESULTS: Dietary N-acetyl-L-cysteine supplementation significantly increased resistance to oxidative stress, heat stress, and UV irradiation in C. elegans. In addition, N-acetyl-L-cysteine supplementation significantly extended both the mean and maximum lifespan of C. elegans. The mean lifespan was extended by up to 30.5% with 5 mM N-acetyl-L-cysteine treatment, and the maximum lifespan was increased by 8 days. N-acetyl-L-cysteine supplementation also increased the total number of progeny produced and extended the gravid period of C. elegans. The green fluorescent protein reporter assay revealed that expression of the stress-responsive genes, sod-3 and hsp-16.2, increased significantly following N-acetyl-L-cysteine treatment. CONCLUSION: N-acetyl-L-cysteine supplementation confers a longevity phenotype in C. elegans, possibly through increased resistance to environmental stressors.

The production of rare earth elements group via tributyl phosphate extraction and precipitation stripping using oxalic acid

Directory of Open Access Journals (Sweden)

Esmaeil Jorjani

2016-11-01

Full Text Available In this study, solvent extraction and precipitation stripping were used to produce rare earth elements (REEs. Tributyl phosphate (TBP was used to extract yttrium, lanthanum, cerium, and neodymium from an aqueous solution produced by nitric acid leaching of apatite concentrate. In the extraction stage, the effects of TBP concentration, pH, contact time, temperature, and phase ratio were investigated. The results show that about 95%, 90%, 87% and 80% of neodymium, cerium, lanthanum, and yttrium, respectively, can be extracted in optimum conditions of extraction. Hot, deionized water was used to scrub the impurities from the loaded organic phase. The results showed that three stages of scrubbing with a phase ratio (Va/Vo of five removed about 80%, 30%, 27%, and 15% of Ca, Mg, Fe, and P, respectively, from loaded TBP, while less than 9% of total REEs was lost. The effects on precipitation stripping of oxalic acid concentration, contact time, and phase ratio were investigated. The results showed that precipitation stripping is a viable alternative to traditional acid stripping in the REEs production process. Mixed REEs oxide with an assay of about 90% can be achieved as a final product.

Density functional and ab initio study of the tautomeric forms of 3-acetyl tetronic and 3-acetyl tetramic acids

International Nuclear Information System (INIS)

Skylaris, Chris-Kriton; Igglessi-Markopoulou, Olga; Detsi, Anastasia; Markopoulos, John

2003-01-01

We propose all the accessible paths of interconversion between the tautomers of 3-acetyl tetronic and 3-acetyl tetramic acids by performing calculations with the density functional B3LYP method and the ab initio MP2 method. Our findings clarify at the atomic level the mechanisms of the equilibria between these tautomers, a topic so far only partially understood on the basis of studies by nuclear magnetic resonance (NMR) spectroscopy. We show that thermal effects via relative Gibbs free energies ΔG must be taken into account in order to reach good quantitative agreement with the available experimental information on the ratios of the most stable tautomers. The calculated 1 H and 13 C chemical shifts are in agreement with the experimental values from NMR spectroscopy

Transport of citrate-coated silver nanoparticles in unsaturated sand

Science.gov (United States)

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.

13C Metabolic Flux Analysis for systematic metabolic engineering of S. cerevisiae for overproduction of fatty acids.

Directory of Open Access Journals (Sweden)

Amit Ghosh

2016-10-01

Full Text Available Efficient redirection of microbial metabolism into the abundant production of desired bioproducts remains non-trivial. Here we used flux-based modeling approaches to improve yields of fatty acids in S. cerevisiae. We combined 13C labeling data with comprehensive genome-scale models to shed light onto microbial metabolism and improve metabolic engineering efforts. We concentrated on studying the balance of acetyl-CoA, a precursor metabolite for the biosynthesis of fatty acids. A genome-wide acetyl-CoA balance study showed ATP citrate lyase from Y. lipolytica as a robust source of cytoplasmic acetyl-CoA and malate synthase as a desirable target for down-regulation in terms of acetyl-CoA consumption. These genetic modifications were applied to S. cerevisiae WRY2, a strain that is capable of producing 460 mg L of free fatty acids. With the addition of ATP citrate lyase and down-regulation of malate synthase the engineered strain produced 26 per cent more free fatty acids. Further increases in free fatty acid production of 33 per cent were obtained by knocking out the cytoplasmic glycerol-3-phosphate dehydrogenase, which flux analysis had shown was competing for carbon flux upstream with the carbon flux through the acetyl-CoA production pathway in the cytoplasm. In total, the genetic interventions applied in this work increased fatty acid production by 70 per cent.

Value of gallium 67 citrate scintigraphy in ophthalmology

International Nuclear Information System (INIS)

Ivanez-Alloschery, Monique.

1978-01-01

For ophthalmologists scintigraphy appears as a simple method to detect endoocular or endoorbital abnormalities. However none of the many scintigraphic methods described seems reliable enough to be used alone. One of the latest isotopic explorations using gallium 67 citrate, a tracer considered tumour-tropic might be able to solve this problem. The aim of this work is to judge the value of the method in the diagnosis of malignant endoocular and endoorbital tumours on the basis of 24 anatomoclinical observations. It may be concluded from this study that ocular gallium 67 citrate scintigraphy, which gave no clearly positive results at all but some doubtful results in the case of endoocular tumours more than 5 mm in diameter, is to be rejected; fluorescein angiography and ocular echograhy provide more elements for an accurate etiological diagnosis. Orbital scintigraphy on the other hand seems to be a necessary complement to a tomodensitometric examination since both methods offer diagnostic information without systematic recurse to carotid arteriography or orbital phlebography, sometimes dangerous for the patient [fr

Diffuse abdominal uptake of Ga-67 citrate in a patient with hypoproteinemia

International Nuclear Information System (INIS)

Kim, E.E.; Gobuty, A.; Gutierrez, C.

1983-01-01

A 3-wk-old male, with abdominal distention and severe hypoproteinemia from poor nutrition, underwent a study that showed a persistent diffuse abdominal uptake of Ga-67 citrate, indicating pyogenic or tuberculous peritonitis. However, there were no corresponding clinical or laboratory findings. After a 1-wk course of hyperalimentation with albumin, furosemide, and protein, repeat radiographs showed reduction in bowel gas. It is suggested that hypoproteinemia should be considered as a possibility in the differential diagnosis when there is diffuse abdominal uptake of Ga-67 citrate, with careful clinical correlation. Possible mechanism of Ga-67 uptake in the peritoneal cavity is suggested

Neptunium speciation (complexation and redox behaviour) in aqueous citrate medium

Energy Technology Data Exchange (ETDEWEB)

Bonin, L.; Ansoborlo, E.; Moisy, Ph. [CEA Marcoule (France)

2005-07-01

Full text of publication follows: In the framework of the French Environmental Nuclear Toxicology programme, additional experiments related to the decorporation of actinides are planned. The lack of information on the neptunium behaviour within blood and the inefficiency of therapeutic treatments, led us to study the complexation of this element with basic anions. Within this purpose, the in vitro behaviour of Np{sup IV} and Np{sup V} in simple media simulating biological media was studied: blood plasma is one of the media of interest and it can be simulated, from a chemical point of view, by an aqueous solution with pH 7.4, containing ions such as citrate (1.6 10{sup -4} mol/L), lactate (1.5 10{sup -3} mol/L), CO{sub 3}{sup 2-} (2.5 10{sup -2} mol/L), PO{sub 4}{sup 3-} (1.1 10{sup -3} mol/L), SO{sub 4}{sup 2-} (3.3 10{sup -4} mol/L) and Cl{sup -} (9 10{sup -2} mol/L). This study was more specifically focused on the behaviour of neptunium with citrate ion, which is also a basic ligand to consider when one wishes to study the migration of actinides in the environment, since it exists in significant amounts in the ground due to its production by the plants. In order to determine the speciation of this system, spectrophotometry was more particularly used. Concerning the complexation phenomenon, the existence of several complexes of Np{sup V} with various acid-basic forms of the citrate anion was observed; regarding Np{sup IV}, two complexes, with 1:1 and 1:2 stoichiometry, have been respectively observed. The reactivity of Np{sup VI} is probably similar to the behaviour of U{sup VI}, which is reported in literature to form a complex with a 1:1 stoichiometry with the Cit{sup 3-}anion From the quantitative study of these equilibria, it has been possible to determine the values of various equilibrium constants. Concerning the stability of neptunium towards oxido-reduction, it was confirmed that Np{sup VI} was very quickly reduced to Np{sup V} by the citrate anions

Early detection of interstitial pneumonia by 67Ga-citrate scintigraphy

International Nuclear Information System (INIS)

Ito, Shinsaku; Mikami, Riichiro; Ryujin, Yoshitada

1985-01-01

In this paper we report our recent experience indicating usefulness of 67 Ga-citrate scintigraphy in 4 cases with inflammatory pulmonary diseases. These cases showed abnormal pulmonary 67 Ga uptake with normal chest radiographs. The first case with malignant lymphoma and the second one with lung cancer suffered from pulmonary infection following secondary immuno-insufficiency due to radiotherapy and chemotherapy. Pneumocystis carinii was suspected as causative agent in the first case, and gram negative bacilli in the second case. The third case with lung cancer developed radiation pneumonia after radiotherapy. The fourth case with acute bronchitis developed drug induced interstitial pneumonia presumably due to minocycline administration. It is concluded that 67 Ga-citrate scintigraphy is more sensitive for early detection of interstitial pneumonia than routine chest radiography. (author)

Evaluation of oral abdominal contrast agent containing ferric ammonium citrate

International Nuclear Information System (INIS)

Shiga, Toshiko; Kawamura, Yasutaka; Iwasaki, Toshiko

1991-01-01

We evaluated the effectiveness of oral MRI contrast agent containing ferric ammonium citrate. Twenty patients were arbitrarily divided into 2 groups according to the given dose of 100 and 200 mg Fe of oral MRI contrast agent. MRI was performed before and immediately after ingesting 300 ml solution of oral MRI contrast agent using a 1.5 T superconducting system (GE: Signa). Each dose of 100 and 200 mg Fe of oral MRI contrast agent produced sufficient enhancement of gastrointestinal tract, enough to make clear the pancreatic contour and porta hepatis. There was no significant change in blood and urine analysis observed after taking oral MRI contrast agent. The use of ferric ammonium citrate as an oral MRI contrast agent seems to add valuable information in performing upper abdominal MRI imaging. (author)

Utilization by the isolated perfused rat liver of N-acetyl-D-(1-/sup 14/C)galactosamine and N-brace/sup 3/H)-acetyl-D-galactosamine for the biosynthesis of glycoproteins

Energy Technology Data Exchange (ETDEWEB)

MacNicoll, A D; Wusteman, F S; Powell, G M; Curtis, C G [University Coll., Cardiff (UK)

1978-08-15

The isolated perfused rat liver system has been used to monitor the utilization of N-(/sup 3/H)acetyl-D-galactosamine and N-acetyl-D-(1-/sup 14/C)galactosamine for the biosynthesis of radiolabeled glycoproteins, which are subsequently secreted into the plasma. Both radiolabels appear in a number of different glycoproteins, predominantly as sialic acid and N-acetylglucosamine. The ratio of labelled sialic acid to labelled N-acetylglucosamine varies for different glycoproteins, but the bulk of N-acetyl-D-galactosamine is incorporated without deacetylation.

Structural, spectroscopic and Thermal Studies of Potassium Di-hydrogen Citrate Crystal

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N.D. Pandya

2017-04-01

Full Text Available Potassium dihydrogen citrate (KDC finds wide applications in food products. Pure potassium dihydrogen citrate crystal was grown by slow solvent evaporation technique at room temperature. Grown crystal exhibited needle like morphology. The powder XRD shows triclinic structure symmetry with lattice parameters a=11.820 Å, b=14.970 Å, c=9.442 Å with angles α = 91.60°, β = 93.35°, γ = 110°. The presence of various functional groups of grown crystal was confirmed by using FT-IR spectroscopy. The thermogram indicates the thermal stability of the sample up to 100oC and then decomposes slowly into oxide stage through two stages. The results are discussed here.

Criticality parameters for uranyl nitrate or plutonium nitrate systems in tributyl phosphate/kerosine and water

International Nuclear Information System (INIS)

Weber, W.

1985-01-01

This report presents the calculated values of smallest critical masses and volumina and neutron physical parameters for uranyl nitrate (3, 4, 5% U-235) or plutonium nitrate (5% Pu-240), each in a 30 per cent solution of tributyl phosphate (TBP)/kerosine. For the corresponding nitrate-water solutions, newly calculated results are presented together with a revised solution density model. A comparison of the data shows to what extent the criticality of nitrate-TBP/kerosine systems can be assessed on the basis of nitrate-water parameters, revealing that such data can be applied to uranyl nitrate/water systems, taking into account that the smallest critical mass of uranyl nitrate-TBP/kerosine systems, up to a 5 p.c. U-235 enrichment, is by 4.5 p.c. at the most smaller than that of UNH-water solutions. Plutonium nitrate (5% Pu-240) in the TBP/kerosine solution will have a smallest critical mass of up to 7 p.c. smaller, as compared with the water data. The suitability of the computing methods and cross-sections used is verified by recalculating experiments carried out to determine the lowest critical enrichment of uranyl nitrate. The calculated results are well in agreement with experimental data. The lowest critical enrichment is calculated to be 2.10 p.c. in the isotope U-235. (orig.) [de

Downregulation of RWA genes in hybrid aspen affects xylan acetylation and wood saccharification.

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Pawar, Prashant Mohan-Anupama; Ratke, Christine; Balasubramanian, Vimal K; Chong, Sun-Li; Gandla, Madhavi Latha; Adriasola, Mathilda; Sparrman, Tobias; Hedenström, Mattias; Szwaj, Klaudia; Derba-Maceluch, Marta; Gaertner, Cyril; Mouille, Gregory; Ezcurra, Ines; Tenkanen, Maija; Jönsson, Leif J; Mellerowicz, Ewa J

2017-06-01

High acetylation of angiosperm wood hinders its conversion to sugars by glycoside hydrolases, subsequent ethanol fermentation and (hence) its use for biofuel production. We studied the REDUCED WALL ACETYLATION (RWA) gene family of the hardwood model Populus to evaluate its potential for improving saccharification. The family has two clades, AB and CD, containing two genes each. All four genes are expressed in developing wood but only RWA-A and -B are activated by master switches of the secondary cell wall PtNST1 and PtMYB21. Histochemical analysis of promoter::GUS lines in hybrid aspen (Populus tremula × tremuloides) showed activation of RWA-A and -B promoters in the secondary wall formation zone, while RWA-C and -D promoter activity was diffuse. Ectopic downregulation of either clade reduced wood xylan and xyloglucan acetylation. Suppressing both clades simultaneously using the wood-specific promoter reduced wood acetylation by 25% and decreased acetylation at position 2 of Xylp in the dimethyl sulfoxide-extracted xylan. This did not affect plant growth but decreased xylose and increased glucose contents in the noncellulosic monosaccharide fraction, and increased glucose and xylose yields of wood enzymatic hydrolysis without pretreatment. Both RWA clades regulate wood xylan acetylation in aspen and are promising targets to improve wood saccharification. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

Enclomiphene citrate stimulates testosterone production while preventing oligospermia: a randomized phase II clinical trial comparing topical testosterone.

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Wiehle, Ronald D; Fontenot, Gregory K; Wike, Jenny; Hsu, Kuang; Nydell, Jennifer; Lipshultz, Larry

2014-09-01

To determine the effect of enclomiphene citrate in men with secondary hypogonadism. Phase II clinical trial. Community dwelling men making visits to physician offices. Men with secondary hypogonadism. Oral administration of enclomiphene citrate or 1% topical T gel. Luteinizing hormone, FSH, T, and semen analysis. Treatment with enclomiphene citrate resulted in increased morning serum T, E2, and LH levels similar to those obtained with a topical T gel in men with secondary hypogonadism. Follicle-stimulating hormone and LH were increased with enclomiphene, and sperm counts were conserved. Enclomiphene citrate reverses the two hallmarks of secondary hypogonadism, namely, low serum total T and low or inappropriately normal LH while preserving sperm production. NCT01270841 (ClinicalTrials.gov Identifier NCT01270841). Copyright © 2014 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Acetylation-Dependent Chromatin Reorganization by BRDT, a Testis-Specific Bromodomain-Containing Protein

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Pivot-Pajot, Christophe; Caron, Cécile; Govin, Jérôme; Vion, Alexandre; Rousseaux, Sophie; Khochbin, Saadi

2003-01-01

The association between histone acetylation and replacement observed during spermatogenesis prompted us to consider the testis as a source for potential factors capable of remodelling acetylated chromatin. A systematic search of data banks for open reading frames encoding testis-specific bromodomain-containing proteins focused our attention on BRDT, a testis-specific protein of unknown function containing two bromodomains. BRDT specifically binds hyperacetylated histone H4 tail depending on the integrity of both bromodomains. Moreover, in somatic cells, the ectopic expression of BRDT triggered a dramatic reorganization of the chromatin only after induction of histone hyperacetylation by trichostatin A (TSA). We then defined critical domains of BRDT involved in its activity. Both bromodomains of BRDT, as well as flanking regions, were found indispensable for its histone acetylation-dependent remodelling activity. Interestingly, we also observed that recombinant BRDT was capable of inducing reorganization of the chromatin of isolated nuclei in vitro only when the nuclei were from TSA-treated cells. This assay also allowed us to show that the action of BRDT was ATP independent, suggesting a structural role for the protein in the remodelling of acetylated chromatin. This is the first demonstration of a large-scale reorganization of acetylated chromatin induced by a specific factor. PMID:12861021

Targeted amino-terminal acetylation of recombinant proteins in E. coli.

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Matthew Johnson

2010-12-01

Full Text Available One major limitation in the expression of eukaryotic proteins in bacteria is an inability to post-translationally modify the expressed protein. Amino-terminal acetylation is one such modification that can be essential for protein function. By co-expressing the fission yeast NatB complex with the target protein in E.coli, we report a simple and widely applicable method for the expression and purification of functional N-terminally acetylated eukaryotic proteins.

Structural and Thermodynamic Analysis of the First Mononuclear Aqueous Aluminum Citrate Complex Using DFT Calculations.

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de Noronha, Antonio Luiz Oliveira; Guimarães, Luciana; Duarte, Hélio Anderson

2007-05-01

Structural and thermodynamic properties of the mononuclear Al/citrate complexes have been theoretically investigated aiming to understand the coordination mechanism at an atomic level. GGA-DFT/PCM calculations have been performed for the different conformations and tautomers arising from the Al(3+) and citric acid (H3L) interaction in aqueous solution. The Gibbs reaction energies were estimated based on the reaction of the trigonal planar Al(OH)3 and H3L to form different Al-citrate complexes. The estimated Gibbs free reaction energies for the [AlL], [AlHL](+), and [Al(OH)L](-) species are in good agreement with the experimental values. In these species, the Al(3+) center is coordinated by two carboxylic and the tertiary hydroxyl groups of the citrate. Conversely to what has been proposed based on the experiments, the present theoretical calculations indicate that the citric acid hydroxyl group remains protonated upon the coordination of Al(3+). In fact, our model turns out to be more consistent with the relative pKa values of citrate protonation groups and with the hydrolysis constant of the H2O bound to Al(3+) leading to better agreement with the available experimental data.

Antiproliferative effects of TSA, PXD‑101 and MS‑275 in A2780 and MCF7 cells: Acetylated histone H4 and acetylated tubulin as markers for HDACi potency and selectivity.

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Androutsopoulos, Vasilis P; Spandidos, Demetrios A

2017-12-01

Inhibition of histone deacetylase enzymes (HDACs) has been well documented as an attractive target for the development of chemotherapeutic drugs. The present study investigated the effects of two prototype hydroxamic acid HDAC inhibitors, namely Trichostatin A (TSA) and Belinostat (PXD‑101) and the benzamide Entinostat (MS‑275) in A2780 ovarian carcinoma and MCF7 breast adenocarcinoma cells. The three HDACi inhibited the proliferation of A2780 and MCF7 cells at comparable levels, below the µM range. Enzyme inhibition assays in a cell‑free system showed that TSA was the most potent inhibitor of total HDAC enzyme activity followed by PXD‑101 and MS‑275. Incubation of A2780 and MCF7 cells with the hydroxamates TSA and PXD‑101 for 24 h resulted in a dramatic increase of acetylated tubulin induction (up to 30‑fold for TSA). In contrast to acetylated tubulin, western blot analysis and flow cytometry indicated that the induction of acetylated histone H4 was considerably smaller. The benzamide MS‑275 exhibited nearly a 2‑fold induction of acetylated histone H4 and an even smaller induction of acetylated tubulin in A2780 and MCF7 cells. Taken together, these data suggest that although the three HDACi were equipotent in inhibiting proliferation of MCF7 and A2780 cells, only the benzamide MS‑275 did not induce acetylated tubulin expression, a marker of class IIb HDACs.

Luminal localization of α-tubulin K40 acetylation by cryo-EM analysis of fab-labeled microtubules.

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Virupakshi Soppina

Full Text Available The αβ-tubulin subunits of microtubules can undergo a variety of evolutionarily-conserved post-translational modifications (PTMs that provide functional specialization to subsets of cellular microtubules. Acetylation of α-tubulin residue Lysine-40 (K40 has been correlated with increased microtubule stability, intracellular transport, and ciliary assembly, yet a mechanistic understanding of how acetylation influences these events is lacking. Using the anti-acetylated tubulin antibody 6-11B-1 and electron cryo-microscopy, we demonstrate that the K40 acetylation site is located inside the microtubule lumen and thus cannot directly influence events on the microtubule surface, including kinesin-1 binding. Surprisingly, the monoclonal 6-11B-1 antibody recognizes both acetylated and deacetylated microtubules. These results suggest that acetylation induces structural changes in the K40-containing loop that could have important functional consequences on microtubule stability, bending, and subunit interactions. This work has important implications for acetylation and deacetylation reaction mechanisms as well as for interpreting experiments based on 6-11B-1 labeling.

Tributyl phosphate removal from reprocessing off-gas streams using a selected sorbent

International Nuclear Information System (INIS)

Parker, G.B.

1980-01-01

Laboratory experiments used small laboratory-scale columns packed with selected sorbent materials to remove tributyl phosphate (TBP) and iodine at conditions approaching those in actual reprocessing off-gas streams. The sorbent materials for TBP removal were placed upstream of iodine sorbent materials to protect the iodine sorbent from the deleterious effects of TBP. Methyl iodide in an airstream containing 30% TBP in normal paraffin hydrocarbons (NPH) and water vapor was metered to two packed columns of sorbents simultaneously (in parallel). One column contained a segment of 8-in. x 14-in. mesh alumina sorbent for TBP removal, the other did not. The measure of the effectiveness of TBP sorbent materials for TBP removal was determined by comparing the iodine retention of the iodine sorbent materials in the two parallel columns. Results from an 18 wt % Ag substituted mordenite iodine sorbent indicated that the iodine retention capacity of the sorbent was reduced 60% by the TBP and that the column containing iodine sorbent material protected by the alumina TBP sorbent retained 30 times more iodine than the column without TBP sorbent. TBP concentration was up to 500 mg/m 3 . Similar experiments using a 7 wt % Ag impregnated silica gel indicated that the TBP vapor had little effect on the iodine retention of the silica gel material. The stoichiometric maximum amount of iodine was retained by the silica gel material. Further experiments were conducted assessing the effects of NO 2 on iodine retention of this 7 wt % Ag sorbent. After the two columns were loaded with iodine in the presence of TBP (in NPH), one column was subjected to 2 vol % NO 2 in air. From visual comparison of the two columns, it appeared that the NO 2 regenerated the silica gel iodine sorbent and that iodine was washed off the silica gel iodine sorbent leaving the sorbent in the original state

Morphological, mechanical, barrier and properties of films based on acetylated starch and cellulose from barley.

Science.gov (United States)

El Halal, Shanise Lisie Mello; Colussi, Rosana; Biduski, Bárbara; Evangelho, Jarine Amaral do; Bruni, Graziella Pinheiro; Antunes, Mariana Dias; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

2017-01-01

Biodegradable films of native or acetylated starches with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. The tensile strength of the acetylated starch film was lower than those of the native starch film, without fibers. The addition of fibers increased the tensile strength and decreased the elongation and the moisture of native and acetylated starches films. The acetylated starch film showed higher water solubility when compared to native starch film. The addition of cellulose fibers reduced the water solubility of the acetylated starch film. The films reinforced with cellulose fiber exhibited a higher initial decomposition temperature and thermal stability. The mechanical, barrier, solubility, and thermal properties are factors which direct the type of the film application in packaging for food products. The films elaborated with acetylated starches of low degree of substitution were not effective in a reduction of the water vapor permeability. The addition of the cellulose fiber in acetylated and native starches films can contribute to the development of more resistant films to be applied in food systems that need to maintain their integrity. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

On the nature of citrate-derived surface species on Ag nanoparticles: Insights from X-ray photoelectron spectroscopy

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Mikhlin, Yuri L.; Vorobyev, Sergey A.; Saikova, Svetlana V.; Vishnyakova, Elena A.; Romanchenko, Alexander S.; Zharkov, Sergey M.; Larichev, Yurii V.

2018-01-01

Citrate is an important stabilizing, reducing, and complexing reagent in the wet chemical synthesis of nanoparticles of silver and other metals, however, the exact nature of adsorbates, and its mechanism of action are still uncertain. Here, we applied X-ray photoelectron spectroscopy, soft X-ray absorption near-edge spectroscopy, and other techniques in order to determine the surface composition and to specify the citrate-related species at Ag nanoparticles immobilized from the dense hydrosol prepared using room-temperature reduction of aqueous Ag+ ions with ferrous ions and citrate as stabilizer (Carey Lea method). It was found that, contrary to the common view, the species adsorbed on the Ag nanoparticles are, in large part, products of citrate decomposition comprising an alcohol group and one or two carboxylate bound to the surface Ag, and minor unbound carboxylate group; these may also be mixtures of citrate with lower molecular weight anions. No ketone groups were specified, and very minor surface Ag(I) and Fe (mainly, ferric oxyhydroxides) species were detected. Moreover, the adsorbates were different at AgNPs having various size and shape. The relation between the capping and the particle growth, colloidal stability of the high-concentration sol and properties of AgNPs is briefly considered.

Clinical efficacy of toothpaste containing potassium citrate in treating dentin hypersensitivity

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Shih-Ya Shen

2009-12-01

Conclusion: The prevalence of dentin hypersensitivity in this study was 38%. The use of desensitizing toothpaste containing potassium citrate with oral hygiene instruction can effectively reduce dentin hypersensitivity.

Acetylated rice starches films with different levels of amylose: Mechanical, water vapor barrier, thermal, and biodegradability properties.

Science.gov (United States)

Colussi, Rosana; Pinto, Vânia Zanella; El Halal, Shanise Lisie Mello; Biduski, Bárbara; Prietto, Luciana; Castilhos, Danilo Dufech; Zavareze, Elessandra da Rosa; Dias, Alvaro Renato Guerra

2017-04-15

Biodegradable films from native or acetylated starches with different amylose levels were prepared. The films were characterized according to the mechanical, water vapor barrier, thermal, and biodegradability properties. The films from acetylated high amylose starches had higher moisture content and water solubility than the native high amylose starch film. However, the acetylation did not affect acid solubility of the films, regardless of the amylose content. Films made from high and medium amylose rice starches were obtained; however low amylose rice starches, whether native or acetylated, did not form films with desirable characteristics. The acetylation decreased the tensile strength and increased the elongation of the films. The acetylated starch-based films had a lower decomposition temperature and higher thermal stability than native starch films. Acetylated starches films exhibited more rapid degradation as compared with the native starches films. Copyright © 2016 Elsevier Ltd. All rights reserved.

Evidence for lysine acetylation in the coat protein of a polerovirus.

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Cilia, Michelle; Johnson, Richard; Sweeney, Michelle; DeBlasio, Stacy L; Bruce, James E; MacCoss, Michael J; Gray, Stewart M

2014-10-01

Virions of the RPV strain of Cereal yellow dwarf virus-RPV were purified from infected oat tissue and analysed by MS. Two conserved residues, K147 and K181, in the virus coat protein, were confidently identified to contain epsilon-N-acetyl groups. While no functional data are available for K147, K181 lies within an interfacial region critical for virion assembly and stability. The signature immonium ion at m/z 126.0919 demonstrated the presence of N-acetyllysine, and the sequence fragment ions enabled an unambiguous assignment of the epsilon-N-acetyl modification on K181. We hypothesize that selection favours acetylation of K181 in a fraction of coat protein monomers to stabilize the capsid by promoting intermonomer salt bridge formation.

Removal of radioactive cesium from soil by ammonium citrate solution and ionic liquid

International Nuclear Information System (INIS)

Ishiwata, Shunji; Kitakouji, Manabu; Taga, Atsushi; Ogata, Fumihiko; Ouchi, Hidekazu; Yamanishi, Hirokuni; Inagaki, Masayo

2015-01-01

Radioactive cesium has strongly bound soil as time proceeded, which could not be cleaved in mild condition. We have found that serial treatment of ammonium citrate solution and ionic liquid removed radioactive cesium from soil effectively. The sequence of the treatment is crucial, since inverse serial treatment or mixture of two kinds of solution did not show such an effect, which suggested that ammonium citrate unlocked trapped cesium in soil and ionic liquid solved it. We also found that repeating serial treatment and prolonged treatment time additively removed cesium from soil. (author)

FecB, a periplasmic ferric-citrate transporter from E. coli, can bind different forms of ferric-citrate as well as a wide variety of metal-free and metal-loaded tricarboxylic acids.

Science.gov (United States)

Banerjee, Sambuddha; Paul, Subrata; Nguyen, Leonard T; Chu, Byron C H; Vogel, Hans J

2016-01-01

The Escherichia coli Fec system, consisting of an outer membrane receptor (FecA), a periplasmic substrate binding protein (FecB) and an inner membrane permease-ATPase type transporter (FecC/D), plays an important role in the uptake and transport of Fe(3+)-citrate. Although several FecB sequences from various organisms have been reported, there are no biophysical or structural data available for this protein to date. In this work, using isothermal titration calorimetry (ITC), we report for the first time the ability of FecB to bind different species of Fe(3+)-citrate as well as other citrate complexes with trivalent (Ga(3+), Al(3+), Sc(3+) and In(3+)) and a representative divalent metal ion (Mg(2+)) with low μM affinity. Interestingly, ITC experiments with various iron-free di- and tricarboxylic acids show that FecB can bind tricarboxylates with μM affinity but not biologically relevant dicarboxylates. The ability of FecB to bind with metal-free citrate is also observed in (1)H,(15)N HSQC-NMR titration experiments reported here at two different pH values. Further, differential scanning calorimetry (DSC) experiments indicate that the ligand-bound form of FecB has greater thermal stability than ligand-free FecB under all pH and ligand conditions tested, which is consistent with the idea of domain closure subsequent to ligand binding for this type of periplasmic binding proteins.

The Effect of Acetyl-L-Carnitine Administration on Persons with Down Syndrome

Science.gov (United States)

Pueschel, Siegfried M.

2006-01-01

Since previous investigations reported improvements in cognition of patients with dementia after acetyl-L-carnitine therapy and since there is an increased risk for persons with Down syndrome to develop Alzheimer disease, this study was designed to investigate the effect of acetyl-L-carnitine administration on neurological, intellectual, and…

Defective enamel and bone development in sodium-dependent citrate transporter (NaCT Slc13a5 deficient mice.

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Armando R Irizarry

Full Text Available There has been growing recognition of the essential roles of citrate in biomechanical properties of mineralized tissues, including teeth and bone. However, the sources of citrate in these tissues have not been well defined, and the contribution of citrate to the regulation of odontogenesis and osteogenesis has not been examined. Here, tooth and bone phenotypes were examined in sodium-dependent citrate transporter (NaCT Slc13a5 deficient C57BL/6 mice at 13 and 32 weeks of age. Slc13a5 deficiency led to defective tooth development, characterized by absence of mature enamel, formation of aberrant enamel matrix, and dysplasia and hyperplasia of the enamel organ epithelium that progressed with age. These abnormalities were associated with fragile teeth with a possible predisposition to tooth abscesses. The lack of mature enamel was consistent with amelogenesis imperfecta. Furthermore, Slc13a5 deficiency led to decreased bone mineral density and impaired bone formation in 13-week-old mice but not in older mice. The findings revealed the potentially important role of citrate and Slc13a5 in the development and function of teeth and bone.

Autoradiographic study of nuclear protein acetylation during Locust spermiogenesis

International Nuclear Information System (INIS)

Bouvier, D.; Chevaillier, P.

1975-01-01

Autoradiographic studies, at the light and electron microscope level, demonstrate that spermatid nuclei of the Locust Locusta migratoria incorporate 3 H-acetate, especially during the first stages of spermiogenesis. The highest level of acetate incorporation is observed during stage II of spermiogenesis. During this stage and the following, the spermatid nucleus undergoes a number of structural and chemical modifications: chromatin decondenses and somatic histones are progressively replaced by newly synthesized arginine-rich proteins. Therefore, the higher degree of acetylation of nuclear components coincides with chromatin decondensation and precedes the protein transition occurring in later stages. Cytochemical and autoradiographic tests have been realized so as to localize 3 H-acetate in the nuclear components. Trichloracetic acid was used at various concentrations: the action of hydrochloric acid, pronase and DNase was also tested. The results support the idea that proteins, and among them histones, are the only nuclear components to be acetylated during spermiogenesis. Thus, histone acetylation seems to play an important role in modulating histone-DNA interactions and allowing histone replacement [fr

Temporal Regulation of the Bacillus subtilis Acetylome and Evidence for a Role of MreB Acetylation in Cell Wall Growth.

Science.gov (United States)

Carabetta, Valerie J; Greco, Todd M; Tanner, Andrew W; Cristea, Ileana M; Dubnau, David

2016-05-01

N ε -Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the Bacillus subtilis acetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter. The past decade highlighted N ε -lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases in B. subtilis . To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized MreB, the cell

A Comparative 68Ga-Citrate and 68Ga-Chloride PET/CT Imaging of Staphylococcus aureus Osteomyelitis in the Rat Tibia

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Petteri Lankinen

2018-01-01

Full Text Available There may be some differences in the in vivo behavior of 68Ga-chloride and 68Ga-citrate leading to different accumulation profiles. This study compared 68Ga-citrate and 68Ga-chloride PET/CT imaging under standardized experimental models. Methods. Diffuse Staphylococcus aureus tibial osteomyelitis and uncomplicated bone healing rat models were used (n=32. Two weeks after surgery, PET/CT imaging was performed on consecutive days using 68Ga-citrate or 68Ga-chloride, and tissue accumulation was confirmed by ex vivo analysis. In addition, peripheral quantitative computed tomography and conventional radiography were performed. Osteomyelitis was verified by microbiological analysis and specimens were also processed for histomorphometry. Results. In PET/CT imaging, the SUVmax of 68Ga-chloride and 68Ga-citrate in the osteomyelitic tibias (3.6 ± 1.4 and 4.7 ± 1.5, resp. were significantly higher (P=0.0019 and P=0.0020, resp. than in the uncomplicated bone healing (2.7 ± 0.44 and 2.5 ± 0.49, resp.. In osteomyelitic tibias, the SUVmax of 68Ga-citrate was significantly higher than the uptake of 68Ga-chloride (P=0.0017. In animals with uncomplicated bone healing, no difference in the SUVmax of 68Ga-chloride or 68Ga-citrate was seen in the operated tibias. Conclusions. This study further corroborates the use of 68Ga-citrate for PET imaging of osteomyelitis.

Histone acetylation and CREB binding protein are required for neuronal resistance against ischemic injury.

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Ferah Yildirim

Full Text Available Epigenetic transcriptional regulation by histone acetylation depends on the balance between histone acetyltransferase (HAT and deacetylase activities (HDAC. Inhibition of HDAC activity provides neuroprotection, indicating that the outcome of cerebral ischemia depends crucially on the acetylation status of histones. In the present study, we characterized the changes in histone acetylation levels in ischemia models of focal cerebral ischemia and identified cAMP-response element binding protein (CREB-binding protein (CBP as a crucial factor in the susceptibility of neurons to ischemic stress. Both neuron-specific RNA interference and neurons derived from CBP heterozygous knockout mice showed increased damage after oxygen-glucose deprivation (OGD in vitro. Furthermore, we demonstrated that ischemic preconditioning by a short (5 min subthreshold occlusion of the middle cerebral artery (MCA, followed 24 h afterwards by a 30 min occlusion of the MCA, increased histone acetylation levels in vivo. Ischemic preconditioning enhanced CBP recruitment and histone acetylation at the promoter of the neuroprotective gene gelsolin leading to increased gelsolin expression in neurons. Inhibition of CBP's HAT activity attenuated neuronal ischemic preconditioning. Taken together, our findings suggest that the levels of CBP and histone acetylation determine stroke outcome and are crucially associated with the induction of an ischemia-resistant state in neurons.

Nitric Oxide Modulates Histone Acetylation at Stress Genes by Inhibition of Histone Deacetylases.

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Mengel, Alexander; Ageeva, Alexandra; Georgii, Elisabeth; Bernhardt, Jörg; Wu, Keqiang; Durner, Jörg; Lindermayr, Christian

2017-02-01

Histone acetylation, which is an important mechanism to regulate gene expression, is controlled by the opposing action of histone acetyltransferases and histone deacetylases (HDACs). In animals, several HDACs are subjected to regulation by nitric oxide (NO); in plants, however, it is unknown whether NO affects histone acetylation. We found that treatment with the physiological NO donor S-nitrosoglutathione (GSNO) increased the abundance of several histone acetylation marks in Arabidopsis (Arabidopsis thaliana), which was strongly diminished in the presence of the NO scavenger 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. This increase was likely triggered by NO-dependent inhibition of HDAC activity, since GSNO and S-nitroso-N-acetyl-dl-penicillamine significantly and reversibly reduced total HDAC activity in vitro (in nuclear extracts) and in vivo (in protoplasts). Next, genome-wide H3K9/14ac profiles in Arabidopsis seedlings were generated by chromatin immunoprecipitation sequencing, and changes induced by GSNO, GSNO/2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide or trichostatin A (an HDAC inhibitor) were quantified, thereby identifying genes that display putative NO-regulated histone acetylation. Functional classification of these genes revealed that many of them are involved in the plant defense response and the abiotic stress response. Furthermore, salicylic acid, which is the major plant defense hormone against biotrophic pathogens, inhibited HDAC activity and increased histone acetylation by inducing endogenous NO production. These data suggest that NO affects histone acetylation by targeting and inhibiting HDAC complexes, resulting in the hyperacetylation of specific genes. This mechanism might operate in the plant stress response by facilitating the stress-induced transcription of genes. © 2017 American Society of Plant Biologists. All Rights Reserved.

Proteome-wide mapping of the Drosophila acetylome demonstrates a high degree of conservation of lysine acetylation

DEFF Research Database (Denmark)

Weinert, Brian T; Wagner, Sebastian A; Horn, Heiko

2011-01-01

Posttranslational modification of proteins by acetylation and phosphorylation regulates most cellular processes in living organisms. Surprisingly, the evolutionary conservation of phosphorylated serine and threonine residues is only marginally higher than that of unmodified serines and threonines....... With high-resolution mass spectrometry, we identified 1981 lysine acetylation sites in the proteome of Drosophila melanogaster. We used data sets of experimentally identified acetylation and phosphorylation sites in Drosophila and humans to analyze the evolutionary conservation of these modification sites...... between flies and humans. Site-level conservation analysis revealed that acetylation sites are highly conserved, significantly more so than phosphorylation sites. Furthermore, comparison of lysine conservation in Drosophila and humans with that in nematodes and zebrafish revealed that acetylated lysines...

Acetylation Is Crucial for p53-Mediated Ferroptosis and Tumor Suppression

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Shang-Jui Wang

2016-10-01

Full Text Available Although previous studies indicate that loss of p53-mediated cell cycle arrest, apoptosis, and senescence does not completely abrogate its tumor suppression function, it is unclear how the remaining activities of p53 are regulated. Here, we have identified an acetylation site at lysine K98 in mouse p53 (or K101 for human p53. Whereas the loss of K98 acetylation (p53K98R alone has very modest effects on p53-mediated transactivation, simultaneous mutations at all four acetylation sites (p534KR: K98R+ 3KR[K117R+K161R+K162R] completely abolish its ability to regulate metabolic targets, such as TIGAR and SLC7A11. Notably, in contrast to p533KR, p534KR is severely defective in suppressing tumor growth in mouse xenograft models. Moreover, p534KR is still capable of inducing the p53-Mdm2 feedback loop, but p53-dependent ferroptotic responses are markedly abrogated. Together, these data indicate the critical role of p53 acetylation in ferroptotic responses and its remaining tumor suppression activity.

Structure of 1,5-Anhydro-D-Fructose: X-ray Analysis of Crystalline Acetylated Dimeric Forms

DEFF Research Database (Denmark)

Lundt, Inge; Andersen, Søren Møller; Marcussen, Jan

1998-01-01

Acetylation of 1,5-anhydro-D-fructose under acidic conditions gave two crystalline acetylated dimeric forms, which by X-ray analysis were shown to be diastereomeric spiroketals formed between C-2 and C-2´/C-3´. The structures of the compounds differed only at the configuration at C-2. Acetylation...... or benzoylation of 1,5-anhydro-D-fructose in pyridine yielded 3,6-di-O-acetyl-1,5-anhydro-4-deoxy-D-glycero-hex-3-enos-2-ulopyra -nose or crystalline 1,5-anhydro-3,6-di-O-benzoyl-4-deoxy-D-glycero-hex-3-enos-2-ulo-py ranose....

Women taking the "blue pill" (sildenafil citrate): such a big deal?

Science.gov (United States)

Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto

2014-01-01

For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra(®)) in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate) should be kept as the last option.

Effect of Acetyl Group on Mechanical Properties of Chitin/Chitosan Nanocrystal: A Molecular Dynamics Study

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Junhe Cui

2016-01-01

Full Text Available Chitin fiber is the load-bearing component in natural chitin-based materials. In these materials, chitin is always partially deacetylated to different levels, leading to diverse material properties. In order to understand how the acetyl group enhances the fracture resistance capability of chitin fiber, we constructed atomistic models of chitin with varied acetylation degree and analyzed the hydrogen bonding pattern, fracture, and stress-strain behavior of these models. We notice that the acetyl group can contribute to the formation of hydrogen bonds that can stabilize the crystalline structure. In addition, it is found that the specimen with a higher acetylation degree presents a greater resistance against fracture. This study describes the role of the functional group, acetyl groups, in crystalline chitin. Such information could provide preliminary understanding of nanomaterials when similar functional groups are encountered.

Oxygen-dependent acetylation and dimerization of the corepressor CtBP2 in neural stem cells

International Nuclear Information System (INIS)

Karaca, Esra; Lewicki, Jakub; Hermanson, Ola

2015-01-01

The transcriptional corepressor CtBP2 is essential for proper development of the nervous system. The factor exerts its repression by interacting in complexes with chromatin-modifying factors such as histone deacetylases (HDAC) 1/2 and the histone demethylase LSD1/KDM1. Notably, the histone acetyl transferase p300 acetylates CtBP2 and this is an important regulatory event of the activity and subcellular localization of the protein. We recently demonstrated an essential role for CtBPs as sensors of microenvironmental oxygen levels influencing the differentiation potential of neural stem cells (NSCs), but it is not known whether oxygen levels influence the acetylation levels of CtBP factors. Here we show by using proximity ligation assay (PLA) that CtBP2 acetylation levels increased significantly in undifferentiated, proliferating NSCs under hypoxic conditions. CtBP2 interacted with the class III HDAC Sirt1 but this interaction was unaltered in hypoxic conditions, and treatment with the Sirt1 inhibitor Ex527 did not result in any significant change in total CtBP2 acetylation levels. Instead, we revealed a significant decrease in PLA signal representing CtBP2 dimerization in NSCs under hypoxic conditions, negatively correlating with the acetylation levels. Our results suggest that microenvironmental oxygen levels influence the dimerization and acetylation levels, and thereby the activity, of CtBP2 in proliferating NSCs

Oxygen-dependent acetylation and dimerization of the corepressor CtBP2 in neural stem cells

Energy Technology Data Exchange (ETDEWEB)

Karaca, Esra; Lewicki, Jakub; Hermanson, Ola, E-mail: Ola.Hermanson@ki.se

2015-03-01

The transcriptional corepressor CtBP2 is essential for proper development of the nervous system. The factor exerts its repression by interacting in complexes with chromatin-modifying factors such as histone deacetylases (HDAC) 1/2 and the histone demethylase LSD1/KDM1. Notably, the histone acetyl transferase p300 acetylates CtBP2 and this is an important regulatory event of the activity and subcellular localization of the protein. We recently demonstrated an essential role for CtBPs as sensors of microenvironmental oxygen levels influencing the differentiation potential of neural stem cells (NSCs), but it is not known whether oxygen levels influence the acetylation levels of CtBP factors. Here we show by using proximity ligation assay (PLA) that CtBP2 acetylation levels increased significantly in undifferentiated, proliferating NSCs under hypoxic conditions. CtBP2 interacted with the class III HDAC Sirt1 but this interaction was unaltered in hypoxic conditions, and treatment with the Sirt1 inhibitor Ex527 did not result in any significant change in total CtBP2 acetylation levels. Instead, we revealed a significant decrease in PLA signal representing CtBP2 dimerization in NSCs under hypoxic conditions, negatively correlating with the acetylation levels. Our results suggest that microenvironmental oxygen levels influence the dimerization and acetylation levels, and thereby the activity, of CtBP2 in proliferating NSCs.

Preparation of lead titanate zirconate from metal citrates; Preparacao do titanato zirconato de chumbo a partir dos citratos metalicos

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Bastos, C M.R.

1994-12-31

Lead titanate zirconate (PZT) preparation from its metal constituent citrates have been investigated. Metal citrates were obtained by forced precipitation using a dehydration alcohol mixture. Salt solutions of lead nitrate and octahydrated zirconyl chloride, and titanium tetrachloride were treated separately with citric acid and ammonium hydroxide. Zirconium, titanium and lead oxides resulted from thermal decomposition of corresponding citrates at 500{sup 0} C, 450{sup 0} C and 250{sup 0} C, respectively. Lead titanate (PT) and lead zirconate (P Z) were obtained by calcining at 450{sup 0} C and 500{sup 0} C, respectively, after adequate heating of citrates mechanically mixed in ethyl ether. PZT samples were obtained with different starting stoichiometry. Rhombohedral PZT-1 53/47 sample was prepared from co precipitating zirconyl ammonium and ammonium lead citrates in presence of ethanolic titanium oxide dispersion, and calcinating at 800{sup 0} C. Rhombohedral PZT-q 52/48 sample was obtained from heating at 500{sup 0} C for 2 hours a mixture of metal citrates coprecipitated by dehydration mixture of acetone-ethanol-formic acid (2:1:0,06). Tetragonal PZT-m stoichiometry 53/47 sample were obtained by calcining at after 600{sup 0} C for 2 hours after heating a mechanically mixed metal citrates. PT phase arose at 400{sup 0} C. PZT-m powders obtained in a range of 400{sup 0} C-800{sup 0} C were isostatically pressed, and sintered at 1100{sup 0} C and 1200{sup 0} C in saturated Pb O atmosphere. Rhombohedral sintered PZT was obtained with 7,78 g.cm{sup -3} at 1200{sup 0} C. (author). 123 refs, 53 figs, 32 tabs.

Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance.

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Liu, Jiping; Magalhaes, Jurandir V; Shaff, Jon; Kochian, Leon V

2009-02-01

Aluminum-activated root malate and citrate exudation play an important role in plant Al tolerance. This paper characterizes AtMATE, a homolog of the recently discovered sorghum and barley Al-tolerance genes, shown here to encode an Al-activated citrate transporter in Arabidopsis. Together with the previously characterized Al-activated malate transporter, AtALMT1, this discovery allowed us to examine the relationship in the same species between members of the two gene families for which Al-tolerance genes have been identified. AtMATE is expressed primarily in roots and is induced by Al. An AtMATE T-DNA knockdown line exhibited very low AtMATE expression and Al-activated root citrate exudation was abolished. The AtALMT1 AtMATE double mutant lacked both Al-activated root malate and citrate exudation and showed greater Al sensitivity than the AtALMT1 mutant. Therefore, although AtALMT1 is a major contributor to Arabidopsis Al tolerance, AtMATE also makes a significant but smaller contribution. The expression patterns of AtALMT1 and AtMATE and the profiles of Al-activated root citrate and malate exudation are not affected by the presence or absence of the other gene. These results suggest that AtALMT1-mediated malate exudation and AtMATE-mediated citrate exudation evolved independently to confer Al tolerance in Arabidopsis. However, a link between regulation of expression of the two transporters in response to Al was identified through work on STOP1, a transcription factor that was previously shown to be necessary for AtALMT1 expression. Here we show that STOP1 is also required for AtMATE expression and Al-activated citrate exudation.

Structure Elucidation of New Acetylated Saponins, Lessoniosides A, B, C, D, and E, and Non-Acetylated Saponins, Lessoniosides F and G, from the Viscera of the Sea Cucumber Holothuria lessoni

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Bahrami, Yadollah; Franco, Christopher M. M.

2015-01-01

Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on the presence of the acetyl group. The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid. Ion fingerprints from the glycosidic cleavage provided information on the mass of the aglycone (core), and the sequence and type of monosaccharides that constitute the sugar moiety. The tandem mass spectra of the saponin precursor ions [M + Na]+ provided a wealth of detailed structural information on the glycosidic bond cleavages. As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A–E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development. The presented strategy allows a rapid, reliable and complete analysis of native saponins. PMID:25603350

Aqueous solubility of calcium citrate and interconversion between the tetrahydrate and the hexahydrate as a balance between endothermic dissolution and exothermic complex formation

DEFF Research Database (Denmark)

Hedegaard, Martina Vavrusova; Skibsted, Leif Horsfelt

2016-01-01

Aqueous solubility of calcium citrate tetrahydrate was found to decrease with increasing temperature, while solubility of hexahydrate increased with a transition temperature at 51.6 °C. Excess citrate increased calcium citrate solubility but decreased the calcium ion activity of the saturated sol...

Tofacitinib Citrate for Ulcerative Keratitis in a Patient with Rheumatoid Arthritis

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Philip B. Meadow

2014-01-01

Full Text Available Purpose. To report a case of a patient with rheumatoid arthritis (RA treated with tofacitinib citrate. Methods. Observational case report. Results. A 59-year-old patient, with a history of rheumatoid arthritis, on methotrexate 10 mg PO qwk and IV abatacept 750 mg/month, presented with photosensitivity, foreign body sensation, pain, redness, and blurry vision of her right eye (RE. Visual acuity of the RE was 20/200 and 20/20 of the left eye (LE. The slit lamp examination of the RE revealed dryness, 2+ injection of the conjunctiva, and pericentral ulceration of the cornea with 20–30% stromal thinning, pannus, and diffuse punctate epithelial erosions. The anterior chamber appeared normal. Laboratory values revealed elevated levels of rheumatoid factor, anticyclic citrullinated peptide antibodies, and C-reactive protein. The patient was switched to tofacitinib citrate 5 mg PO b.i.d, underwent corneal gluing, and was given prednisone acetate 1% gt TID, polytrim gt TID, neomycin-polymyxin-dexameth gt QD, FreshKote lubricant 1.8% gt QID, moxifloxacin 0.5% gt QID, and preservative free artificial tears Q1H. Within one week, laboratory values normalized, symptoms diminished, and the cornea reepithelialized. Conclusion. RA can present with ulcerative keratitis. Tofacitinib citrate, steroids, and corneal gluing were found to halt the progression of keratolysis and promote reepithelialization.

The extracellular release of Schistosoma mansoni HMGB1 nuclear protein is mediated by acetylation

International Nuclear Information System (INIS)

Coutinho Carneiro, Vitor; Moraes Maciel, Renata de; Caetano de Abreu da Silva, Isabel; Furtado Madeira da Costa, Rodrigo; Neto Paiva, Claudia; Torres Bozza, Marcelo; Rosado Fantappie, Marcelo

2009-01-01

Schistosoma mansoni HMGB1 (SmHMGB1) was revealed to be a substrate for the parasite histone acetyltransferases SmGCN5 and SmCBP1. We found that full-length SmHMGB1, as well as its HMG-box B (but not HMG-box A) were acetylated in vitro by SmGCN5 and SmCBP1. However, SmCBP1 was able to acetylate both substrates more efficiently than SmGCN5. Interestingly, the removal of the C-terminal acidic tail of SmHMGB1 (SmHMGB1ΔC) resulted in increased acetylation of the protein. We showed by mammalian cell transfection assays that SmHMGB1 and SmHMGB1ΔC were transported from the nucleus to the cytoplasm after sodium butyrate (NaB) treatment. Importantly, after NaB treatment, SmHMGB1 was also present outside the cell. Together, our data suggest that acetylation of SmHMGB1 plays a role in cellular trafficking, culminating with its secretion to the extracellular milieu. The possible role of SmHMGB1 acetylation in the pathogenesis of schistosomiasis is discussed.

The extracellular release of Schistosoma mansoni HMGB1 nuclear protein is mediated by acetylation

Energy Technology Data Exchange (ETDEWEB)

Coutinho Carneiro, Vitor; Moraes Maciel, Renata de; Caetano de Abreu da Silva, Isabel; Furtado Madeira da Costa, Rodrigo [Instituto de Bioquimica Medica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil); Neto Paiva, Claudia; Torres Bozza, Marcelo [Departamento de Imunologia, Instituto de Microbiologia Professor Paulo de Goes, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil); Rosado Fantappie, Marcelo, E-mail: fantappie@bioqmed.ufrj.br [Instituto de Bioquimica Medica, Programa de Biotecnologia e Biologia Molecular, Universidade Federal do Rio de Janeiro, CCS, Ilha do Fundao, Rio de Janeiro 21941-590 (Brazil)

2009-12-25

Schistosoma mansoni HMGB1 (SmHMGB1) was revealed to be a substrate for the parasite histone acetyltransferases SmGCN5 and SmCBP1. We found that full-length SmHMGB1, as well as its HMG-box B (but not HMG-box A) were acetylated in vitro by SmGCN5 and SmCBP1. However, SmCBP1 was able to acetylate both substrates more efficiently than SmGCN5. Interestingly, the removal of the C-terminal acidic tail of SmHMGB1 (SmHMGB1{Delta}C) resulted in increased acetylation of the protein. We showed by mammalian cell transfection assays that SmHMGB1 and SmHMGB1{Delta}C were transported from the nucleus to the cytoplasm after sodium butyrate (NaB) treatment. Importantly, after NaB treatment, SmHMGB1 was also present outside the cell. Together, our data suggest that acetylation of SmHMGB1 plays a role in cellular trafficking, culminating with its secretion to the extracellular milieu. The possible role of SmHMGB1 acetylation in the pathogenesis of schistosomiasis is discussed.

Does adding metformin to clomifene citrate lead to higher pregnancy rates in a subset of women with polycystic ovary syndrome?

OpenAIRE

Moll, E.; Korevaar, J.C.; Bossuyt, P.M.M.; van der Veen, F.

2008-01-01

BACKGROUND An RCT among newly diagnosed, therapy naive women with polycystic ovary syndrome (PCOS) showed no significant differences in ovulation rate, ongoing pregnancy rate or spontaneous abortion rate in favour of clomifene citrate plus metformin compared with clomifene citrate. We wanted to assess whether there are specific subgroups of women with PCOS in whom clomifene citrate plus metformin leads to higher pregnancy rates. METHODS Subgroup analysis based on clinical and biochemical para...

Regulation of Nur77 protein turnover through acetylation and deacetylation induced by p300 and HDAC1.

Science.gov (United States)

Kang, Shin-Ae; Na, Hyelin; Kang, Hyun-Jin; Kim, Sung-Hye; Lee, Min-Ho; Lee, Mi-Ock

2010-09-15

Although the roles of Nur77, an orphan member of the nuclear hormone receptor superfamily, in the control of cellular proliferation, apoptosis, inflammation, and glucose metabolism, are well recognized, the molecular mechanism regulating the activity and expression of Nur77 is not fully understood. Acetylation of transcription factors has emerged recently as a major post-translational modification that regulates protein stability and transcriptional activity. Here, we examined whether Nur77 is acetylated, and we characterized potential associated factors. First, Nur77 was found to be an acetylated protein when examined by immunoprecipitation and western blotting using acetyl protein-specific antibodies. Second, expression of p300, which possesses histone acetyltransferase activity, enhanced the acetylation and protein stability of Nur77. Treatment with a histone deacetylase (HDAC) inhibitor, trichostatin A, also increased Nur77 acetylation. Among the several types of HDACs, HDAC1 was found as the major enzyme affecting protein level of Nur77. HDAC1 decreased the acetylation level, protein level, and transcriptional activity of Nur77. Interestingly, overexpression of Nur77 induced expression of both p300 and HDAC1. Finally, the expression of Nur77 increased along with that of p300, but decreased with induction of HDAC1 after treatment with epithelial growth factor, nerve growth factor, or 6-mercaptopurine, suggesting that the self-control of the acetylation status contributes to the transient induction of Nur77 protein. Taken together, these results demonstrate that acetylation of Nur77 is modulated by p300 and HDAC1, and suggest that acetylation is an important post-translational modification for the rapid turnover of Nur77 protein. Copyright 2010 Elsevier Inc. All rights reserved.

[PHI regulates histone methylation and acetylation in Burkitt lymphoma Daudi cell line].

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Hong, Ling-Ling; Ma, Xu-Dong; Huang, Yi-Qun

2011-02-01

This study was purposed to investigate the effects of phenylhexyl isothiocyanate (PHI) on Burkitt lymphoma Daudi cell line and regulation of histone acetylation and methylation in Daudi cells, and to explore the potential mechanism. The apoptotic rate of Daudi cells treated with PHI was measured by flow cytometry, the changes of histone H3 and H4 acetylation, histone H3K9 and H3K4 methylation in Daudi cells treated with PHI were detected by Western blot. The results showed that PHI could induce apoptosis of Daudi cells, increased the acetylation level of H3 and H4, enhanced the methylation of H3K4, but reduced the methylation of H3K9. It is concluded that the PHI can up-regulate the acetylation level of histone H3 associated with transcription stimulation and the methylation of histone H3K4, down-regulate the methylation on histone H3K9 associated with transcription inhibition, promotes the apoptosis of Daudi cells. PHI may be a potential agent for target therapy of lymphoma.

Effect of the acetylation process on native starches of yam (Dioscorea spp.

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Jairo Salcedo Mendoza

2016-07-01

Full Text Available In Colombia, it is necessary to produce native and modified starches for the use of amylaceous raw materials of major socioeconomic importance. In this study, the effects of the acetylation process on structural, morphological and functional properties of native starches yam, Dioscorea spp. (D. alata and D. rotundata were evaluated. Chemical modification by esterification with acetic anhydride was performed at different reaction times, and morphological and structural changes were assessed using the following techniques: infrared spectroscopy (FTIR, X-ray diffraction and scanning electron microscopy (SEM. Acetylation produced slight changes in the granule morphology, and a decreased degree of crystallinity (DC associated with a slight increase in the amylose content was observed. The introduction of acetyl groups into the starch structure caused a decrease in the gelatinization temperature and an increased retro gradation tendency. The acetylated starches had low degrees of substitution (DS<0.2, meaning they can be used in the food industry, considering that they showed greater stability, greater water absorption capacity and better solubility than native starches.

A study of the effects of citrate-coated silver nanoparticles on RAW 264.7 cells using a toolbox of cytotoxic endpoints

Energy Technology Data Exchange (ETDEWEB)

Bastos, V. [University of Aveiro, CESAM, Department of Biology (Portugal); Duarte, I. F. [University of Aveiro, CICECO—Aveiro Institute of Materials, Department of Chemistry (Portugal); Santos, C., E-mail: csantos@fc.up.pt; Oliveira, H., E-mail: holiveira@ua.pt [University of Aveiro, CESAM, Department of Biology (Portugal)

2017-05-15

Citrate-coated silver nanoparticles (citrate-AgNPs) are among the most commonly used nanomaterials, widely present in industrial and biomedical products. In this study, the cytotoxicity of 30-nm citrate-AgNPs on the macrophage cell line RAW 264.7 was evaluated, using a battery of cytotoxicity endpoints (viability, oxidative stress, and cytostaticity/clastogenicity), at 24 and 48 h of exposure. Citrate-AgNPs decreased cell proliferation and viability only at 75 μg/mL, suggesting a low sensitivity of RAW cells to lower doses of these AgNPs. After 24 h of exposure, ROS content decreased in cells exposed to 60 μg/mL AgNPs (IC20 value), corroborating the high tolerance of these cells to citrate-AgNPs. However, these cells suffered an impairment of the cell cycle, shown by an increase at the sub-G1 phase. This increase of the sub-G1 population was correlated with an increase of DNA fragmentation, suggesting an increase of apoptosis. Thus, our data are important to understand the effects of low concentrations (IC20) of citrate-AgNPs on in vitro vital macrophage functions.

The safety and efficacy of ranitidine bismuth citrate in combination with antibiotics for the eradication of Helicobacter pylori

NARCIS (Netherlands)

Wyeth, J. W.; Pounder, R. E.; Duggan, A. E.; O'Morain, C. A.; Schaufelberger, H. D.; de Koster, E. H.; Rauws, E. A.; Bardhan, K. D.; Gilvarry, J.; Buckley, M. J.; Gummett, P. A.; Logan, R. P.

1996-01-01

Ranitidine bismuth citrate is a novel salt of ranitidine and a bismuth citrate complex. It has intrinsic antisecretory and anti-Helicobacter pylori activity, but monotherapy rarely eradicates H. pylori infection in man. A pilot study to investigate rates of H. pylori eradication achieved by

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

Science.gov (United States)

2011-12-30

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain...) published in the Federal Register the countervailing duty order on citric acid and certain citrate salts... Affirmative Countervailing Duty Determinations: Citric Acid and Certain Citrate Salts, 74 FR 25705 (May 29...

78 FR 54625 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Notice of Partial...

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2013-09-05

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain Citrate Salts From the People's Republic of China: Notice of Partial Rescission of Countervailing Duty... of the countervailing duty (CVD) order on citric acid and certain citrate salts from the People's...

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

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2012-12-13

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-937] Citric Acid and Certain... review of the antidumping duty order on citric acid and certain citrate salts from the People's Republic..., regarding ``Second Antidumping Administrative Review of Citric Acid and Certain Citrate Salts from the...

Controlled swelling and degradation studies of alginate microbeads in dilute natrium-citrate solutions

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Mitrović Dragana D.

2010-01-01

Full Text Available Alginate hydrogels are widely used in biomedicine due to alginate availability, hydrophilic nature, biocompatibility and biodegradability. Alginate microbeads are particularly attractive for applications in pharmacy and regenerative medicine due to high surface to volume ratio, low mass transfer limitations and simple implantation by injection. Aim of this work was to investigate possibilities for controlled degradation of alginate microbeads in cell culture medium (Dulbecco’s modified Eagle’s medium with Na-citrate added in small concentrations (0.05 - 0.5 mM. Alginate microbeads (1.5% w/w, 800 m in diameter were produced by electrostatic droplet extrusion and evaluated over a period of 10 days regarding appearance, kinetics and degree of swelling as well as biomechanical properties determined in a novel bioreactor with mechanical stimulation under in vivo-like conditions in articular cartilage (10% strain, 337.5 m/s compression rate. In the citrate concentration range investigated, microbeads initially swelled reaching an equilibrium value (~150-170% with respect to the initial mass, upon which they appeared stable for a certain period of time (1 to over 7 days followed by bead bursting and degradation. This degradation process indicated that Na+ ions from the solution initially replaced Ca2+ ions bound mainly to COO- groups in polymannuronate sequences inducing electrostatic repulsion of polymer chains and, consequently, swelling of the beads. Citrate ions assisted in this process by forming insoluble calcium citrate. Thus, the specific rate of the bead swelling increased with the increase in citrate concentration approaching a maximal value of ~0.34 d-1. In the last phase, the beads burst into pieces, which slowly continued to degrade by replacement of Ca2+ ions bonded to polyguluronate blocks in the egg-box structure. Compression moduli for packed beds of control, freshly produced microbeads, and microbeads swelled at the equilibrium

The evidence for clinically significant bias in plasma glucose between liquid and lyophilized citrate buffer additive.

Science.gov (United States)

Juricic, Gordana; Saracevic, Andrea; Kopcinovic, Lara Milevoj; Bakliza, Ana; Simundic, Ana-Maria

2016-12-01

Citrate buffer additive has been suggested to be of supreme performance in inhibiting glycolysis. However, there is little evidence in the literature regarding the comparability of glucose concentrations in liquid and lyophilized citrate buffer containing tubes. The aim of this study was to compare glucose concentrations in tubes containing liquid (Glucomedics) and lyophilized citrate buffer (Terumo VENOSAFE™ Glycemia) additive, measured immediately after centrifugation. Blood was collected from forty volunteers into both Glucomedics and Venosafe Glycemia tubes. Blood was centrifuged within 15min from venipuncture and glucose concentration was measured immediately after centrifugation, on the Abbott Architect analyzer. Differences between glucose concentrations in Glucomedics and Terumo tubes were tested using the paired t-test. Mean bias was calculated and compared to recommended quality specification for glucose (i.e. 2.2%). Glucose concentration in Terumo tubes was 3.4% lower than in Glucomedics tubes (Pglucose concentrations in liquid and lyophilized citrate buffer additive tubes (Glucomedics vs. Terumo tubes) measured immediately after centrifugation. This difference may affect the patient outcome due to the misclassification of diabetes. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

A Retrospective Review of the Use of Regional Citrate Anticoagulation in Continuous Venovenous Hemofiltration for Critically Ill Patients

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Anne Kit-Hung Leung

2013-01-01

Full Text Available Background. The emergence of a commercially prepared citrate solution has revolutionized the use of RCA in the intensive care unit (ICU. The aim of this study was to evaluate the safety profile of a commercially prepared citrate solution. Method. Predilution continuous venovenous hemofiltration (CVVH was performed using Prismocitrate 10/2 at 2500 mL/h and a blood flow rate of 150 mL/min. Calcium chloride solution was infused to maintain ionized calcium within 1.0–1.2 mmol/L. An 8.4% sodium bicarbonate solution was infused separately. Treatment was stopped when the predefined clinical target was reached or the filter clotted. Result. 58 sessions of citrate RCA were analyzed. The median circuit lifetime was 26.0 h (interquartile range IQR 21.2–44.3. The percentage of circuits lasting more than 12 h, 24 h, and 48 h was 94.6%, 58.9%, and 16.1%, respectively. There was no incidence of hypernatremia and median pH was 2.5, only four patients had evidence of citrate accumulation. Conclusion. The commercially prepared citrate solution could be used safely in critically ill patients who required CVVH with no major adverse events.

Subclinical abortions in patients treated with clomiphene citrate

International Nuclear Information System (INIS)

Ho, P.C.; Tang, G.W.

1982-01-01

Using radioimmunoassay for human chorionic gonadotrophin beta-subunit, 39 treatment cycles of clomiphene citrate therapy were studied prospectively for incidence of subclinical abortions. Eight treatment cycles resulted in clinically recognizable pregnancies and three other treatment cycles ended up with subclinical abortions. The plasma progesterone levels in patients with subclinical abortions at the 13th day after ovulation were lower than those in patients with normal pregnancies. (author)

PZ, PT and PZT formation from metal citrates

International Nuclear Information System (INIS)

Bastos, C.M.R.; Zaghette, M.A.; Jafelicci Junior, M.; Varela, J.A.

1990-01-01

Lead zirconate, lead titanate and lead titanate-zirconate were obtained by mechanical mixing of lead, titanium and zirconium citrates in ether and by calcination. The process was analyzed by DTA, TGA, IR, pore size distribution and surface area measurements. The results indicate that the decomposition reaction and formation of PZ, PT occur simultaneaously without formation of intermediate compounds. PZT was formed from 500 0 C. (author) [pt

Health-related quality of life in women with newly diagnosed polycystic ovary syndrome randomized between clomifene citrate plus metformin or clomifene citrate plus placebo

NARCIS (Netherlands)

Moll, E.; van Wely, M.; Lambalk, C. B.; Bossuyt, P. M. M.; van der Veen, F.

2012-01-01

What is the health-related quality of life (HRQoL) in women with polycystic ovary syndrome (PCOS) undergoing ovulation induction with clomifene citrate (CC) combined with metformin compared with those using CC combined with placebo? Overall quality of life in women with PCOS treated with CC plus

Health-related quality of life in women with newly diagnosed polycystic ovary syndrome randomized between clomifene citrate plus metformin or clomifene citrate plus placebo

NARCIS (Netherlands)

Moll, E.; van Wely, M.; Lambalk, C.B.; Bossuyt, P.M.M.; van der Veen, F.

2012-01-01

Study Question What is the health-related quality of life (HRQoL) in women with polycystic ovary syndrome (PCOS) undergoing ovulation induction with clomifene citrate (CC) combined with metformin compared with those using CC combined with placebo? Summary Answer Overall quality of life in women with

Efficacy of extended clomifene citrate regimen in comparison with gonadotropins in clomifene citrate-resistant women with polycystic ovary syndrome

OpenAIRE

Mahmoud Fathy Hassan

2014-01-01

Background: Gonadotropins are successful treatment for women with clomifene citrate (CC)-resistant polycystic ovary syndrome (PCOS). The aim of this study was to test the hypothesis that extended CC treatment may be an alternative to gonadotropins in the management of CC-resistant women with PCOS. Methods: A randomized controlled trial comprised 200 women with CC-resistant PCOS were allocated to two equal treatment groups. Patients in the CC group were given 100 mg of CC daily starting fr...

(13)C heteronuclear NMR studies of the interaction of cultured neurons and astrocytes and aluminum blockade of the preferential release of citrate from astrocytes.

Science.gov (United States)

Meshitsuka, Shunsuke; Aremu, David A

2008-02-01

Citrate has been identified as a major tricarboxylic acid (TCA) cycle constituent preferentially released by astrocytes. We undertook the present study to examine further the nature of metabolic compartmentation in central nervous system tissues using (13)C-labeled glucose and to provide new information on the influence of aluminum on the metabolic interaction between neurons and astrocytes. Metabolites released into the culture medium from astrocytes and neuron-astrocyte coculture, as well as the perchloric acid extracts of the cells were analyzed using 2D (1)H and (13)C NMR spectroscopy. Astrocytes released citrate into the culture medium and the released citrate was consumed by neurons in coculture. Citrate release by astrocytes was blocked in the presence of aluminum, with progressive accumulation of citrate within the cells. We propose citrate supply is a more efficient energy source than lactate for neurons to produce ATP, especially in the hypoglycemic state on account of it being a direct component of the TCA cycle. Astrocytes may be the cellular compartment for aluminum accumulation as a citrate complex in the brain.

Preliminary study for acetylation of cassava bagasse starch and microfibrillated cellulose of bamboo

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Silviana Silviana

2018-01-01

Full Text Available Bio composite matrixes have been developed from several biomaterials, such as starch. One of potential resources is starch isolated from cassava bagasse still consisting 30-50% of starch. Reinforcement material may be inserted into bio composite to tough and reduce the drawback of the starch-based bio composite or bio plastic. Microfibrillated cellulose of bamboo (MFC can be used as toughening filler for composite matrix. However, surface modification of material could be employed to alter its properties, such as acetylation of starch-based bio composite and microfibrillated cellulose. The acetylation was executed by using glacial acetic acid (GAA catalyzed with sodium hydroxide. This paper investigates optimum condition of acetylation for bagasse starch (BS and bamboo MFC in different weight ratio of GAA to BS or MFC (1:1, 2:1, 3:1, 1:2, 1:3, temperature range of 30°C to 70°C, and pH range of 7 to 11. Data were resulted from degree of susbtitution for each running. The optimum condition of acetylation of BS was obtained at temperature of 50°C (for BS and 30°C (for MFC, pH of 9, and 2:1 ratio. This acetylation was confirmed by fourier transform infrared spectroscopy and scanning electron microscope.

Direct separation of 67Ga citrate from zinc and copper target materials by an ion exchange

International Nuclear Information System (INIS)

El-Azony, K.M.; Ferieg, Kh.; Saleh, Z.A.

2004-01-01

The separation of 6 7G a from zinc and copper target materials using an anion- f:exchanger (Dowex21K) and 0.1 M citrate buffer at pH 6 is described. The gallium-67 was separated in citrate solution and can be directly used for medical applications. Gallium-67 with a half-life of 78.3 h and gamma-rays with energies of 93, 185 and 300 keV is a cyclotron produced radioisotope for which a considerable demand exists. 6 7G a is frequently produced through proton or deuteron bombardment of natural or enriched Zn targets (Helus and Maier-Borst, 1973). It is usually separated from Zn by ion exchange chromatography (Helus and Maier-Borst, 1973; van der Walt and Strelow, 1983) or by liquid extraction Helus and Maier-Borst, 1973; Hupf and Beaver, 1970). The isotope is usually supplied in citrate solution which is widely used as 6 7G a Gallium citrate which is a well-established radiopharmaceutical for imaging soft tissue tumors and abscesses. Several routes for large scale production of 6 7G a and the development of medical applications have been reported (Silvester and Thakur, 1970; Dahl and Tilbury, 1972; Steyn and Meyer,1973; Vlatkovic et al., 1975; Neirinckx, 1976; Thakur, 1977). Various attempts were carried out to separate gallium-67 by using different ion exchange methods (Strelow et al., 1971; Das and Ramamoorthy, 1995; Boothe et al.,1991) through the labelling of citrate by using 6 7G a was carried out for medical applications

76 FR 2648 - Citric Acid and Certain Citrate Salts From People's Republic of China: Extension of Time Limit...

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2011-01-14

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain Citrate Salts From People's Republic of China: Extension of Time Limit for the Preliminary Results of the... duty order on citric acid and certain citrate salts from the People's Republic of China, covering the...

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

Science.gov (United States)

2012-09-12

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain... (CVD) order on citric acid and certain citrate salts from the People's Republic of China.\\1\\ On [[Page...\\ See Citric Acid and Certain Citrate Salts from the People's Republic of China: Intent to Rescind...

Asymmetric distribution of glucose and indole-3-acetyl-myo-inositol in geostimulated Zea mays seedlings

Science.gov (United States)

Momonoki, Y. S.; Bandurski, R. S. (Principal Investigator)

1988-01-01

Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.

Dichotomy in the Epigenetic Mark Lysine Acetylation is Critical for the Proliferation of Prostate Cancer Cells

International Nuclear Information System (INIS)

Pathak, Ravi; Philizaire, Marc; Mujtaba, Shiraz

2015-01-01

The dynamics of lysine acetylation serve as a major epigenetic mark, which regulates cellular response to inflammation, DNA damage and hormonal changes. Microarray assays reveal changes in gene expression, but cannot predict regulation of a protein function by epigenetic modifications. The present study employs computational tools to inclusively analyze microarray data to understand the potential role of acetylation during development of androgen-independent PCa. The data revealed that the androgen receptor interacts with 333 proteins, out of which at least 92 proteins were acetylated. Notably, the number of cellular proteins undergoing acetylation in the androgen-dependent PCa was more as compared to the androgen-independent PCa. Specifically, the 32 lysine-acetylated proteins in the cellular models of androgen-dependent PCa were mainly involved in regulating stability as well as pre- and post-processing of mRNA. Collectively, the data demonstrate that protein lysine acetylation plays a crucial role during the transition of androgen-dependent to -independent PCa, which importantly, could also serve as a functional axis to unravel new therapeutic targets

Dichotomy in the Epigenetic Mark Lysine Acetylation is Critical for the Proliferation of Prostate Cancer Cells

Energy Technology Data Exchange (ETDEWEB)

Pathak, Ravi [Department of Structural and Chemical Biology, Mount Sinai School of Medicine, 1425 Madison Ave, New York, NY 10029 (United States); Philizaire, Marc [Medgar Evers College, City University of New York, 1638 Bedford Ave, 403D, Brooklyn, NY 11225 (United States); Mujtaba, Shiraz, E-mail: smujtaba@mec.cuny.edu [Department of Structural and Chemical Biology, Mount Sinai School of Medicine, 1425 Madison Ave, New York, NY 10029 (United States); Medgar Evers College, City University of New York, 1638 Bedford Ave, 403D, Brooklyn, NY 11225 (United States)

2015-08-19

The dynamics of lysine acetylation serve as a major epigenetic mark, which regulates cellular response to inflammation, DNA damage and hormonal changes. Microarray assays reveal changes in gene expression, but cannot predict regulation of a protein function by epigenetic modifications. The present study employs computational tools to inclusively analyze microarray data to understand the potential role of acetylation during development of androgen-independent PCa. The data revealed that the androgen receptor interacts with 333 proteins, out of which at least 92 proteins were acetylated. Notably, the number of cellular proteins undergoing acetylation in the androgen-dependent PCa was more as compared to the androgen-independent PCa. Specifically, the 32 lysine-acetylated proteins in the cellular models of androgen-dependent PCa were mainly involved in regulating stability as well as pre- and post-processing of mRNA. Collectively, the data demonstrate that protein lysine acetylation plays a crucial role during the transition of androgen-dependent to -independent PCa, which importantly, could also serve as a functional axis to unravel new therapeutic targets.

Ytterbium 169 citrate in the diagnosis of lung opacities of cancerous origin

International Nuclear Information System (INIS)

Peltier, Patrick.

1976-01-01

Lung scintigraphy for tumour exploration has been widely studied for some years, but unfortunately with the many radioisotopes used at present this examination is not entirely reliable. It seemed interesting therefore to investigate a new tracer, 169 Yb citrate, the properties of which were demonstrated recently by HISADA. To estimate the specificity of this tracer we chose 62 records of different bronchopulmonary diseases. After an introductory review of various diagnostic methods the physical and physiological characteristics of ytterbium citrate and its method of use are described, then the records examined are presented and our thoughts and conclusions discussed. 169 Yb citrate possesses excellent biophysical properties for tumour scintigraphy but this isotope, though causing no radioactive pollution, delivers an appreciable irradiation dose to the patient examined. It has a positive tropism for pathological lung images. The fixation index of the documents taken separately, apart from that of the 14th day, cannot distinguish between benign and malignant diseases. This is possible with the kinetic uptake curve and the index ratios for the 2nd and 14th days. With these diagnostic criteria the overall results are better than those obtained with other commonly used radioisotopes: true positives 70%, false negatives 11%, false positives 4.5% [fr

Acetylation of pregnane X receptor protein determines selective function independent of ligand activation

International Nuclear Information System (INIS)

Biswas, Arunima; Pasquel, Danielle; Tyagi, Rakesh Kumar; Mani, Sridhar

2011-01-01

Research highlights: → Pregnane X receptor (PXR), a major regulatory protein, is modified by acetylation. → PXR undergoes dynamic deacetylation upon ligand-mediated activation. → SIRT1 partially mediates PXR deacetylation. → PXR deacetylation per se induces lipogenesis mimicking ligand-mediated activation. -- Abstract: Pregnane X receptor (PXR), like other members of its class of nuclear receptors, undergoes post-translational modification [PTM] (e.g., phosphorylation). However, it is unknown if acetylation (a major and common form of protein PTM) is observed on PXR and, if it is, whether it is of functional consequence. PXR has recently emerged as an important regulatory protein with multiple ligand-dependent functions. In the present work we show that PXR is indeed acetylated in vivo. SIRT1 (Sirtuin 1), a NAD-dependent class III histone deacetylase and a member of the sirtuin family of proteins, partially mediates deacetylation of PXR. Most importantly, the acetylation status of PXR regulates its selective function independent of ligand activation.

Structure Elucidation of New Acetylated Saponins, Lessoniosides A, B, C, D, and E, and Non-Acetylated Saponins, Lessoniosides F and G, from the Viscera of the Sea Cucumber Holothuria lessoni

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Yadollah Bahrami

2015-01-01

Full Text Available Sea cucumbers produce numerous compounds with a wide range of chemical structural diversity. Among these, saponins are the most diverse and include sulfated, non-sulfated, acetylated and methylated congeners with different aglycone and sugar moieties. In this study, MALDI and ESI tandem mass spectrometry, in the positive ion mode, were used to elucidate the structure of new saponins extracted from the viscera of H. lessoni. Fragmentation of the aglycone provided structural information on the presence of the acetyl group. The presence of the O-acetyl group was confirmed by observing the mass transition of 60 u corresponding to the loss of a molecule of acetic acid. Ion fingerprints from the glycosidic cleavage provided information on the mass of the aglycone (core, and the sequence and type of monosaccharides that constitute the sugar moiety. The tandem mass spectra of the saponin precursor ions [M + Na]+ provided a wealth of detailed structural information on the glycosidic bond cleavages. As a result, and in conjunction with existing literature, we characterized the structure of five new acetylated saponins, Lessoniosides A–E, along with two non-acetylated saponins Lessoniosides F and G at m/z 1477.7, which are promising candidates for future drug development. The presented strategy allows a rapid, reliable and complete analysis of native saponins.

An ultrasensitive and highly selective fluorescent and colorimetric chemosensor for citrate ions based on rhodamine B and its application as the first molecular security keypad lock based on phosphomolybdic acid and citrate inputs

Energy Technology Data Exchange (ETDEWEB)

Tavallali, Hossein, E-mail: Tavallali@pnu.ac.ir; Baezzat, Mohammad-Reza; Deilamy-Rad, Gohar; Parhami, Abolfath; Hasanli, Nahid

2015-04-15

Rhodamine B (Rh{sub B}) has been developed as novel and efficient colorimetric and fluorometric chemosensor for citrate ions (Cit{sup 3−}) in an absolutely aqueous media. The UV–vis absorption and fluorescent emission titrations experiments have been employed to study the sensing process. Rh{sub B} could act as an efficient “ON–OFF” fluorescent chemosensor for phosphomolybdic acid (PMA) based on an electron transfer (ET) process. Also (Rh{sub B}{sup +}){sub 3}.PMA{sup 3−} could operate as an “OFF–ON” fluorescent chemosensor for citrate ions based on a ligand substitution process. The chemosensor Rh{sub B} shows excellent fluorescence sensitivity and selectivity toward citrate in aqueous media, and displays ON–OFF–ON type fluorescence change with alternately adding PMA and citrate to the media along with reversible association–dissociation of the complex. The (Rh{sub B}{sup +}){sub 3}.PMA{sup 3−} can be applied to the quantification of citrate with a linear ranges covering from 0.053 to 0.83 and 0.08 to 1.6 µM by detection limits of 6.0 and 9.1 nM for fluorescence and colorimetric methods respectively. The keypad lock operation is particularly important, as the output of the system depends not only on the proper combination but also on the order of input signals, creating the correct password that can be used to “open” this molecular keypad lock through strong fluorescence emission at 575 nm. As a whole, its various logic gate properties may improve its impact for the development of new-generation “intelligence” digital devices. The ionic PMA and Cit{sup 3−} inputs to (Rh{sub B}{sup +}){sub 3}.PMA{sup 3−} have been mimicked as a superimposed electronic molecular keypad lock. Also indicates that Rh{sub B} is suitable for the detection of Cit{sup 3−} ions in the biological environment. - Highlights: • Our probe is commercially available with good photostability and high quantum yield. • Both color and fluorescence change

67Ga-citrate scanning in gastrointestinal malignancies

International Nuclear Information System (INIS)

Douds, H.N.; Berens, S.V.; Long, R.F.; Caplan, G.E.

1978-01-01

The value of 67 Ga-citrate scanning in cases of gastrointestinal malignancies is discussed. Seven cases are presented, including lymphomas of the stomach, small bowel, and rectum, and adenocarcinomas of the stomach and colon. In a review of the literature, there is general pessimism regarding the use of 67 Ga scans in GI malignancies. Based on previous reports and our own experience, specific clinical situations are cited in which the scan is of considerable value for diagnosis and followup of GI malignancy

Uptake and cytotoxicity of citrate-coated gold nanospheres: Comparative studies on human endothelial and epithelial cells

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Freese Christian

2012-07-01

Full Text Available Abstract Background The use of gold nanoparticles (AuNPs for diagnostic applications and for drug and gene-delivery is currently under intensive investigation. For such applications, biocompatibility and the absence of cytotoxicity of AuNPs is essential. Although generally considered as highly biocompatible, previous in vitro studies have shown that cytotoxicity of AuNPs in certain human epithelial cells was observed. In particular, the degree of purification of AuNPs (presence of sodium citrate residues on the particles was shown to affect the proliferation and induce cytotoxicity in these cells. To expand these studies, we have examined if the effects are related to nanoparticle size (10, 11 nm, 25 nm, to the presence of sodium citrate on the particles' surface or they are due to a varying degree of internalization of the AuNPs. Since two cell types are present in the major barriers to the outside in the human body, we have also included endothelial cells from the vasculature and blood brain barrier. Results Transmission electron microscopy demonstrates that the internalized gold nanoparticles are located within vesicles. Increased cytotoxicity was observed after exposure to AuNPs and was found to be concentration-dependent. In addition, cell viability and the proliferation of both endothelial cells decreased after exposure to gold nanoparticles, especially at high concentrations. Moreover, in contrast to the size of the particles (10 nm, 11 nm, 25 nm, the presence of sodium citrate on the nanoparticle surface appeared to enhance these effects. The effects on microvascular endothelial cells from blood vessels were slightly enhanced compared to the effects on brain-derived endothelial cells. A quantification of AuNPs within cells by ICP-AES showed that epithelial cells internalized a higher quantity of AuNPs compared to endothelial cells and that the quantity of uptake is not correlated with the amount of sodium citrate on the

AuBr3-catalyzed azidation of per-O-acetylated and per-O-benzoylated sugars.

Science.gov (United States)

Rajput, Jayashree; Hotha, Srinivas; Vangala, Madhuri

2018-01-01

Herein we report, for the first time, the successful anomeric azidation of per- O -acetylated and per- O -benzoylated sugars by catalytic amounts of oxophilic AuBr 3 in good to excellent yields. The method is applicable to a wide range of easily accessible per- O -acetylated and per- O -benzoylated sugars. While reaction with per- O -acetylated and per- O -benzoylated monosaccharides was complete within 1-3 h at room temperature, the per- O -benzoylated disaccharides needed 2-3 h of heating at 55 °C.

Inhibition of fatty acid synthesis in isolated adipocytes by 5-(tetradecyloxy)-2-furoic acid.

Science.gov (United States)

Halvorson, D L; McCune, S A

1984-11-01

The compound 5-(tetradecyloxy)-2-furoic acid (TOFA), a hypolipidemic agent, inhibits fatty acid synthesis, lactate and pyruvate accumulation and CO2 release in isolated rat adipocytes. TOFA stimulates the accumulation of citrate. ATP levels are not lowered by TOFA. In comparison with the natural fatty acid, oleate, TOFA exhibited a much greater inhibitory effect on lipogenesis. TOFyl-CoA formation within intact adipocytes was demonstrated. Although not inhibited by TOFA, acetyl-CoA carboxylase is inhibited by TOFyl-CoA. It is proposed that many of the metabolic effects of TOFA in isolated adipocytes can be explained by TOFyl-CoA inhibition of acetyl-CoA carboxylase. TOFA inhibits glycolysis as a secondary event with the primary event of inhibition of fatty acid synthesis causing an accumulation of citrate which is an inhibitor of phosphofructokinase.

Does adding metformin to clomifene citrate lead to higher pregnancy rates in a subset of women with polycystic ovary syndrome?

Science.gov (United States)

Moll, E; Korevaar, J C; Bossuyt, P M M; van der Veen, F

2008-08-01

An RCT among newly diagnosed, therapy naive women with polycystic ovary syndrome (PCOS) showed no significant differences in ovulation rate, ongoing pregnancy rate or spontaneous abortion rate in favour of clomifene citrate plus metformin compared with clomifene citrate. We wanted to assess whether there are specific subgroups of women with PCOS in whom clomifene citrate plus metformin leads to higher pregnancy rates. Subgroup analysis based on clinical and biochemical parameters of 111 women randomized to clomifene citrate plus metformin compared with 114 women randomized to clomifene citrate plus placebo. The data for age, BMI, waist-hip ratio (WHR) and plasma testosterone were available in all women, 2 h glucose in 80% of women and homeostatic model assessment for assessing insulin sensitivity (HOMA) in 50% of women. Of the women who were allocated to the metformin group, 44 women (40%) reached an ongoing pregnancy. In the placebo group, 52 women (46%) reached an ongoing pregnancy. There was a significantly different chance of an ongoing pregnancy for metformin versus placebo between subgroups based on age and WHR (P = 0.014). There was a positive effect of metformin versus placebo on pregnancy rate in older women (>or=28 years) with a high WHR, a negative effect of metformin versus placebo in young women (Metformin may be an effective addition to clomifene citrate in infertile women with PCOS, especially in older and viscerally obese patients.

Hydrolysis of wheat B-starch and characterisation of acetylated maltodextrin.

Science.gov (United States)

Smrčková, Petra; Horský, Jiří; Šárka, Evžen; Koláček, Jaroslav; Netopilík, Miloš; Walterová, Zuzana; Kruliš, Zdeněk; Synytsya, Andrey; Hrušková, Kateřina

2013-10-15

Wheat B-starch was hydrolysed by α-amylase "Liquozyme supra" from Bacillus licheniformis at 90 °C and pH 7. After 2 h, the dextrose equivalent was 18; according to size exclusion chromatography, however, the hydrolysate contained not only dominant malto-oligosaccharides with the degree of polymerisation (DP)40. This non-uniformity of acetylated maltodextrin, both with respect to DP and to DS, must be taken into account in the development of acetylated-maltodextrin applications such as use as plasticisers or compatibilisers in biodegradable composites. Copyright © 2013 Elsevier Ltd. All rights reserved.

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

Science.gov (United States)

2012-12-05

... DEPARTMENT OF COMMERCE International Trade Administration [C-570-938] Citric Acid and Certain... countervailing duty (CVD) order on citric acid and certain citrate salts from the People's Republic of China for... results of this review.\\1\\ \\1\\ See Citric Acid and Certain Citrate Salts from the People's Republic of...

76 FR 47146 - Citric Acid and Certain Citrate Salts From the People's Republic of China: Extension of Time...

Science.gov (United States)

2011-08-04

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-937] Citric Acid and Certain... review of the antidumping duty order on citric acid and certain citrate salts (``citric acid'') from the... of citric acid from the PRC. See Citric Acid and Certain Citrate Salts From the People's Republic of...

A Fe(II)/citrate/UV/PMS process for carbamazepine degradation at a very low Fe(II)/PMS ratio and neutral pH: The mechanisms.

Science.gov (United States)

Ling, Li; Zhang, Dapeng; Fan, Chihhao; Shang, Chii

2017-11-01

A novel Fe(II)/citrate/UV/PMS process for degrading a model micropollutant, carbamazepine (CBZ), at a low Fe(II)/PMS ratio and neutral pH has been proposed in this study, and the mechanisms of radical generation in the system was explored. With a UV dose of 302.4 mJ/cm 2 , an initial pH of 7, and CBZ, PMS, Fe(II) and citrate at initial concentrations of 10, 100, 12 and 26 μM, respectively, the CBZ degradation efficiency reached 71% in 20 min in the Fe(II)/citrate/UV/PMS process, which was 4.7 times higher than that in either the citrate/UV/PMS or Fe(II)/citrate/PMS process. The enhanced CBZ degradation in the Fe(II)/citrate/UV/PMS process was mainly attributed to the continuous activation of PMS by the UV-catalyzed regenerated Fe(II) from a Fe(III)-citrate complex, [Fe 3 O(cit) 3 H 3 ] 2- , which not only maintained Fe(III) soluble at neutral pH, but also increased 6.6 and 2.6 times of its molar absorbance and quantum yield as compared to those of ionic Fe(III), respectively. In the Fe(II)/citrate/UV/PMS process, the SO 4 •- produced from the fast reaction between PMS and the initially-added Fe(II) contributed 11% of CBZ degradation. The PMS activation by the UV radiation and regenerated Fe(II) contributed additional 14% and 46% of CBZ removal, respectively. The low iron and citrate doses and the fast radical generation at neutral pH make the Fe(II)/citrate/UV/PMS process suitable for degrading recalcitrant organic compounds in potable water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Correction of metabolic acidosis with potassium citrate in renal transplant patients and its effect on bone quality.

Science.gov (United States)

Starke, Astrid; Corsenca, Alf; Kohler, Thomas; Knubben, Johannes; Kraenzlin, Marius; Uebelhart, Daniel; Wüthrich, Rudolf P; von Rechenberg, Brigitte; Müller, Ralph; Ambühl, Patrice M

2012-09-01

Acidosis and transplantation are associated with increased risk of bone disturbances. This study aimed to assess bone morphology and metabolism in acidotic patients with a renal graft, and to ameliorate bone characteristics by restoration of acid/base homeostasis with potassium citrate. This was a 12-month controlled, randomized, interventional trial that included 30 renal transplant patients with metabolic acidosis (S-[HCO(3)(-)] 24 mmol/L, or potassium chloride (control group). Iliac crest bone biopsies and dual-energy X-ray absorptiometry were performed at baseline and after 12 months of treatment. Bone biopsies were analyzed by in vitro micro-computed tomography and histomorphometry, including tetracycline double labeling. Serum biomarkers of bone turnover were measured at baseline and study end. Twenty-three healthy participants with normal kidney function comprised the reference group. Administration of potassium citrate resulted in persisting normalization of S-[HCO(3)(-)] versus potassium chloride. At 12 months, bone surface, connectivity density, cortical thickness, and cortical porosity were better preserved with potassium citrate than with potassium chloride, respectively. Serological biomarkers and bone tetracycline labeling indicate higher bone turnover with potassium citrate versus potassium chloride. In contrast, no relevant changes in bone mineral density were detected by dual-energy X-ray absorptiometry. Treatment with potassium citrate in renal transplant patients is efficient and well tolerated for correction of metabolic acidosis and may be associated with improvement in bone quality. This study is limited by the heterogeneity of the investigated population with regard to age, sex, and transplant vintage.

Histone Acetylation is Recruited in Consolidation as a Molecular Feature of Stronger Memories

Science.gov (United States)

Federman, Noel; Fustinana, Maria Sol; Romano, Arturo

2009-01-01

Gene expression is a key process for memory consolidation. Recently, the participation of epigenetic mechanisms like histone acetylation was evidenced in long-term memories. However, until now the training strength required and the persistence of the chromatin acetylation recruited are not well characterized. Here we studied whether histone…

Effect of citrate on Aspergillus niger phytase adsorption and catalytic activity in soil

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Mezeli, Malika; Menezes-Blackburn, Daniel; Zhang, Hao; Giles, Courtney; George, Timothy; Shand, Charlie; Lumsdon, David; Cooper, Patricia; Wendler, Renate; Brown, Lawrie; Stutter, Marc; Blackwell, Martin; Darch, Tegan; Wearing, Catherine; Haygarth, Philip

2015-04-01

Current developments in cropping systems that promote mobilisation of phytate in agricultural soils, by exploiting plant-root exudation of phytase and organic acids, offer potential for developments in sustainable phosphorus use. However, phytase adsorption to soil particles and phytate complexion has been shown to inhibit phytate dephosphorylation, thereby inhibiting plant P uptake, increasing the risk of this pool contributing to diffuse pollution and reducing the potential benefits of biotechnologies and management strategies aimed to utilise this abundant reserve of 'legacy' phosphorus. Citrate has been seen to increase phytase catalytic efficiency towards complexed forms of phytate, but the mechanisms by which citrate promotes phytase remains poorly understood. In this study, we evaluated phytase (from Aspergillus niger) inactivation, and change in catalytic properties upon addition to soil and the effect citrate had on adsorption of phytase and hydrolysis towards free, precipitated and adsorbed phytate. A Langmuir model was fitted to phytase adsorption isotherms showing a maximum adsorption of 0.23 nKat g-1 (19 mg protein g-1) and affinity constant of 435 nKat gˉ1 (8.5 mg protein g-1 ), demonstrating that phytase from A.niger showed a relatively low affinity for our test soil (Tayport). Phytases were partially inhibited upon adsorption and the specific activity was of 40.44 nKat mgˉ1 protein for the free enzyme and 25.35 nKat mgˉ1 protein when immobilised. The kinetics of adsorption detailed that most of the adsorption occurred within the first 20 min upon addition to soil. Citrate had no effect on the rate or total amount of phytase adsorption or loss of activity, within the studied citrate concentrations (0-4mM). Free phytases in soil solution and phytase immobilised on soil particles showed optimum activity (>80%) at pH 4.5-5.5. Immobilised phytase showed greater loss of activity at pH levels over 5.5 and lower activities at the secondary peak at pH 2

Measurement of tributyl phosphate (TBP) in groundwater at a legacy radioactive waste site and its possible role in contaminant mobilisation.

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Rowling, Brett; Kinsela, Andrew S; Comarmond, M Josick; Hughes, Catherine E; Harrison, Jennifer J; Johansen, Mathew P; Payne, Timothy E

2017-11-01

At many legacy radioactive waste sites, organic compounds have been co-disposed, which may be a factor in mobilisation of radionuclides at these sites. Tri-butyl phosphate (TBP) is a component of waste streams from the nuclear fuel cycle, where it has been used in separating actinides during processing of nuclear fuels. Analyses of ground waters from the Little Forest Legacy Site (LFLS) in eastern Australia were undertaken using solid-phase extraction (SPE) followed by gas chromatographic mass spectrometry (GCMS). The results indicate the presence of TBP several decades after waste disposal, with TBP only being detected in the immediate vicinity of the main disposal area. TBP is generally considered to degrade in the environment relatively rapidly. Therefore, it is likely that its presence is due to relatively recent releases of TBP, possibly stemming from leakage due to container degradation. The ongoing presence and solubility of TBP has the potential to provide a mechanism for nuclide mobilisation, with implications for long term management of LFLS and similar legacy waste sites. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

Quantification of active pharmaceutical ingredient and impurities in sildenafil citrate obtained from the Internet.

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Veronin, Michael A; Nutan, Mohammad T; Dodla, Uday Krishna Reddy

2014-10-01

The accessibility of prescription drugs produced outside of the United States, most notably sildenafil citrate (innovator product, Viagra®), has been made much easier by the Internet. Of greatest concern to clinicians and policymakers is product quality and patient safety. The US Food and Drug Administration (FDA) has issued warnings to potential buyers that the safety of drugs purchased from the Internet cannot be guaranteed, and may present a health risk to consumers from substandard products. The objective of this study was to determine whether generic sildenafil citrate tablets from international markets obtained via the Internet are equivalent to the US innovator product regarding major aspects of pharmaceutical quality: potency, accuracy of labeling, and presence and level of impurities. This will help identify aspects of drug quality that may impact public health risks. A total of 15 sildenafil citrate tablets were obtained for pharmaceutical analysis: 14 generic samples from international Internet pharmacy websites and the US innovator product. According to US Pharmacopeial guidelines, tablet samples were tested using high-performance liquid chromatography for potency of active pharmaceutical ingredient (API) and levels of impurities (impurities A, B, C, and D). Impurity levels were compared with International Conference on Harmonisation (ICH) limits. Among the 15 samples, 4 samples possessed higher impurity B levels than the ICH qualification threshold, 8 samples possessed higher impurity C levels than the ICH qualification threshold, and 4 samples possessed more than 1% impurity quantity of maximum daily dose (MDD). For API, 6 of the samples failed to fall within the 5% assay limit. Quality assurance tests are often used to detect formulation defects of drug products during the manufacturing and/or storage process. Results suggest that manufacturing standards for sildenafil citrate generic drug products compared with the US innovator product are not

PSG gene expression is up-regulated by lysine acetylation involving histone and nonhistone proteins.

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Soledad A Camolotto

Full Text Available BACKGROUND: Lysine acetylation is an important post-translational modification that plays a central role in eukaryotic transcriptional activation by modifying chromatin and transcription-related factors. Human pregnancy-specific glycoproteins (PSG are the major secreted placental proteins expressed by the syncytiotrophoblast at the end of pregnancy and represent early markers of cytotrophoblast differentiation. Low PSG levels are associated with complicated pregnancies, thus highlighting the importance of studying the mechanisms that control their expression. Despite several transcription factors having been implicated as key regulators of PSG gene family expression; the role of protein acetylation has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: Here, we explored the role of acetylation on PSG gene expression in the human placental-derived JEG-3 cell line. Pharmacological inhibition of histone deacetylases (HDACs up-regulated PSG protein and mRNA expression levels, and augmented the amount of acetylated histone H3 associated with PSG 5'regulatory regions. Moreover, PSG5 promoter activation mediated by Sp1 and KLF6, via the core promoter element motif (CPE, -147/-140, was markedly enhanced in the presence of the HDAC inhibitor trichostatin A (TSA. This effect correlated with an increase in Sp1 acetylation and KLF6 nuclear localization as revealed by immunoprecipitation and subcellular fractionation assays. The co-activators PCAF, p300, and CBP enhanced Sp1-dependent PSG5 promoter activation through their histone acetylase (HAT function. Instead, p300 and CBP acetyltransferase domain was dispensable for sustaining co-activation of PSG5 promoter by KLF6. CONCLUSIONS/SIGNIFICANCE: Results are consistent with a regulatory role of lysine acetylation on PSG expression through a relaxed chromatin state and an increase in the transcriptional activity of Sp1 and KLF6 following an augmented Sp1 acetylation and KLF6 nuclear localization.

Effect of calcium citrate on bone integration in a rabbit femur defect model.

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Zhang, Wei; Wang, Wei; Chen, Qing-Yu; Lin, Zhong-Qin; Cheng, Shao-Wen; Kou, Dong-Quan; Ying, Xiao-Zhou; Shen, Yue; Cheng, Xiao-Jie; Nie, Peng-Fei; Li, Xiu-Cui; Rompis, Ferdinand An; Huang, Hang; Zhang, Hua; Mu, Zhong-Lin; Peng, Lei

2012-04-01

To explore effect of calcium citrate on bone integration in a rabbit femur defect model, and to compare the bone formation with different sizes by radiological and histological study. Twenty-four male Japanese white rabbits were randomly divided into three groups (Group A, B, C) in this study. Under anesthesia, defects of four sizes (1.2, 1.5, 2.0 and 2.5 mm) were created in each of the rabbits. Commercially pure calcium citrate powder was placed inside the medullary compartment of the femur (Experimental), while in the contralateral femur (Control) nothing was implanted. The defects were analyzed using radiography and histological analysis by using Imagepro-Plus 6.0 software after animal was sacrificed at 4th(Group A), 6th(Group B) and 8th(Group C) weeks postoperatively. Four samples were analyzed for each size of defect and each healing period. The histological and the radiologic evaluation were performed after sacrification of all rabbits on postoperative 4th and 6th weeks, It showed significant difference between the experimental group and the control group when these defects were less than or equal to 2.0 mm. No statistical difference was observed when these defects were larger than 2.0 mm at all healing periods except at the 4th week. Calcium citrate affects the early periods of bone defects healing mechanism in Japanese white rabbits positively, especially when the defect is not too large. We suggest further studies on calcium citrate to determine the effects of various dosages, administration ways and the experimental time on the bone defects. Copyright © 2012 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Cytogenetic effects of sildenafil citrate (Viagra) on SWR/J mouse bone marrow cells.

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Abou-Tarboush, Faisal Mohamed; Abdel-Samad, Mohamed Fathy

2010-10-01

The present study was conducted to investigate the cytogenetic effects of sildenafil citrate in SWR/J mouse bone marrow cells. Thirty-six males and 36 females were used and divided into four groups. Each group contained 18 animals (9 males and 9 females), weighing 30-35 g. These animals were orally administered with a single dose of 13, 26 or 40 mg/kg sildenafil citrate solution. A control group received normal saline in an identical condition. The animals were sacrificed at 12, 24 or 48 h, after the treatment. Chromosome aberrations were investigated in 50 metaphases per animal. No significant differences in the percentages of mitotic indices or in the frequencies of chromosome aberrations were observed between treated male and female mice at any doses or at any time intervals used, therefore, data from the two sexes were pooled when analyzed statistically. No significant (p < 0.05) differences in the percentages of mitotic indices or in the frequencies of chromosome aberrations were observed between sildenafil citrate-treated groups and the control group at any doses or at any time intervals used. However, the percentages of centromeric adhesions increased significantly (p < 0.01) in treated groups as compared with the control group at all doses and at all time intervals used. In conclusion, the results of the present study suggest that sildenafil citrate does not have cytogenetic effects on mouse bone marrow cells, but the centromeric adhesions induced by this drug need further studies to confirm them and to investigate the possible mechanism(s) responsible for such effect.

Histone H4 hyperacetylation and rapid turnover of its acetyl groups in transcriptionally inactive rooster testis spermatids.

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Oliva, R; Mezquita, C

1982-01-01

In order to study the relationship between acetylation of histones, chromatin structure and gene activity, the distribution and turnover of acetyl groups among nucleosomal core histones and the extent of histone H4 acetylation were examined in rooster testis cell nuclei at different stages of spermatogenesis. Histone H4 was the predominant acetylated histone in mature testes. Hyperacetylation of H4 and rapid turnover of its acetyl groups are not univocally correlated with transcriptional activity since they were detected in both genetically active testicular cells and genetically inactive elongated spermatids. During the transition from nucleohistone to nucleoprotamine in elongated spermatids the chromatin undergoes dramatic structural changes with exposition of binding sites on DNA (1). Hyperacetylation of H4 and rapid turnover of its acetyl groups could be correlated with the particular conformation of chromatin in elongated spermatids and might represent a necessary condition for binding of chromosomal proteins to DNA. Images PMID:7162988

Effect of acetylation on antioxidant and cytoprotective activity of polysaccharides isolated from pumpkin (Cucurbita pepo, lady godiva).

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Song, Yi; Yang, Yang; Zhang, Yuyu; Duan, Liusheng; Zhou, Chunli; Ni, Yuanying; Liao, Xiaojun; Li, Quanhong; Hu, Xiaosong

2013-10-15

Acetylation of pumpkin (Cucurbita pepo, lady godiva variety) polysaccharide using acetic anhydride with pyridines as catalyst under different conditions was conducted to obtain different degrees of acetylation on a laboratory scale. Furthermore, antioxidant activities and cytoprotective effects of pumpkin polysaccharide and its acetylated derivatives were investigated employing various established in vitro systems. Results showed that addition of pyridine as catalyst could increase the degree of substitution, whereas volume of acetic anhydride had little effect. The acetylated polysaccharides in DPPH scavenging radical activity assay, superoxide anion radical activity assay and reducing power assay exhibited higher antioxidant activity than that of unmodified polysaccharide. H2O2-induced oxidative damages on rat thymic lymphocyte were also prevented by pumpkin polysaccharide and its acetylated derivatives and the derivatives presented higher protective effects. On the whole, acetylated polysaccharide showed relevant antioxidant activity both in vitro and in a cell system. Copyright © 2013 Elsevier Ltd. All rights reserved.

The influence of metronidazole resistance on the efficacy of ranitidine bismuth citrate triple therapy regimens for Helicobacter pylori infection

NARCIS (Netherlands)

Van der Wouden, EJ; Thijs, JC; Van Zwet, AA; Kooy, A; Kleibeuker, JH

Aim: To assess the influence of metronidazole resistance on the efficacy of ranitidine bismuth citrate-based triple therapy regimens in two consecutive studies. Methods: In the first study, patients with a culture-proven Helicobacter pylori infection were treated with ranitidine bismuth citrate 400

Proteomic investigations of lysine acetylation identify diverse substrates of mitochondrial deacetylase sirt3

DEFF Research Database (Denmark)

Sol, E-ri Maria; Wagner, Sebastian A; Weinert, Brian T

2012-01-01

Lysine acetylation is a posttranslational modification that is dynamically regulated by the activity of acetyltransferases and deacetylases. The human and mouse genomes encode 18 different lysine deacetylases (KDACs) which are key regulators of many cellular processes. Identifying substrates...... of KDACs and pinpointing the regulated acetylation sites on target proteins may provide important information about the molecular basis of their functions. Here we apply quantitative proteomics to identify endogenous substrates of the mitochondrial deacetylase Sirtuin 3 (Sirt3) by comparing site...... by modulating acetylation on diverse substrates. The experimental strategy described here is generic and can be applied to identify endogenous substrates of other lysine deacetylases....

Abnormal splenic uptake of gallium-67 citrate in a case of infectious mononucleosis

International Nuclear Information System (INIS)

Campeau, R.J.; LaCorte, W.S.

1985-01-01

A case of fever of undetermined origin (FUO) demonstrated abnormal intense concentration of Ga-67 citrate in the spleen. Initial workup demonstrated two negative mono spot tests for infectious mononucleosis (IM) but, on hospital day 2, a repeat mono test was positive. The diagnosis was subsequently confirmed by rising heterophilic antibody titers. Six weeks after hospital discharge, repeat Ga-67 citrate imaging demonstrated absence of abnormal splenic activity. To our knowledge, this phenomenon has not been previously described in IM. In the appropriate clinical setting, intense splenic uptake of Ga-67 should alert the clinician to include the possibility of IM in the differential diagnosis

Acetyl-L-carnitine improves aged brain function.

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Kobayashi, Satoru; Iwamoto, Machiko; Kon, Kazuo; Waki, Hatsue; Ando, Susumu; Tanaka, Yasukazu

2010-07-01

The effects of acetyl-L-carnitine (ALCAR), an acetyl derivative of L-carnitine, on memory and learning capacity and on brain synaptic functions of aged rats were examined. Male Fischer 344 rats were given ALCAR (100 mg/kg bodyweight) per os for 3 months and were subjected to the Hebb-Williams tasks and AKON-1 task to assess their learning capacity. Cholinergic activities were determined with synaptosomes isolated from brain cortices of the rats. Choline parameters, the high-affinity choline uptake, acetylcholine (ACh) synthesis and depolarization-evoked ACh release were all enhanced in the ALCAR group. An increment of depolarization-induced calcium ion influx into synaptosomes was also evident in rats given ALCAR. Electrophysiological studies using hippocampus slices indicated that the excitatory postsynaptic potential slope and population spike size were both increased in ALCAR-treated rats. These results indicate that ALCAR increases synaptic neurotransmission in the brain and consequently improves learning capacity in aging rats.

Missing value imputation for microarray gene expression data using histone acetylation information

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Feng Jihua

2008-05-01

Full Text Available Abstract Background It is an important pre-processing step to accurately estimate missing values in microarray data, because complete datasets are required in numerous expression profile analysis in bioinformatics. Although several methods have been suggested, their performances are not satisfactory for datasets with high missing percentages. Results The paper explores the feasibility of doing missing value imputation with the help of gene regulatory mechanism. An imputation framework called histone acetylation information aided imputation method (HAIimpute method is presented. It incorporates the histone acetylation information into the conventional KNN(k-nearest neighbor and LLS(local least square imputation algorithms for final prediction of the missing values. The experimental results indicated that the use of acetylation information can provide significant improvements in microarray imputation accuracy. The HAIimpute methods consistently improve the widely used methods such as KNN and LLS in terms of normalized root mean squared error (NRMSE. Meanwhile, the genes imputed by HAIimpute methods are more correlated with the original complete genes in terms of Pearson correlation coefficients. Furthermore, the proposed methods also outperform GOimpute, which is one of the existing related methods that use the functional similarity as the external information. Conclusion We demonstrated that the using of histone acetylation information could greatly improve the performance of the imputation especially at high missing percentages. This idea can be generalized to various imputation methods to facilitate the performance. Moreover, with more knowledge accumulated on gene regulatory mechanism in addition to histone acetylation, the performance of our approach can be further improved and verified.

Women taking the “blue pill” (sildenafil citrate): such a big deal?

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Lo Monte, Giuseppe; Graziano, Angela; Piva, Isabella; Marci, Roberto

2014-01-01

For years, phosphodiesterase type 5 inhibitors have been used for the treatment of erectile dysfunctions. Due to the similarities between male and female sexual response, several studies have assessed the effects of sildenafil citrate (Viagra®) in women affected by female sexual arousal disorder. The results are still conflicting and the drug is not devoid of adverse effects. Furthermore, female sexual arousal disorder is a heterogeneous condition whose underlying causes are difficult to diagnose and appropriate treatment requires a thorough sexual, psychological, and medical history along with specialist consultations. The clinician should pursue a global approach to the patient with sexual difficulties, while non-hormonal treatment such as phosphodiesterase type 5 inhibitors (ie, sildenafil citrate) should be kept as the last option. PMID:25422584

The bacterial two-hybrid system uncovers the involvement of acetylation in regulating of Lrp activity in Salmonella Typhimurium

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Ran Qin

2016-11-01

Full Text Available Nε-lysine acetylation is an abundant and important Post-translational modification in bacteria. We used the bacterial two-hybrid system to screen the genome library of the Salmonella Typhimurium to identify potential proteins involved in acetyltransferase Pat - or deacetylase CobB-mediated acetylation. Then, the in vitro (deacetylation assays were used to validate the potential targets, such as STM14_1074, NrdF, RhaR. Lrp, a leucine-responsive regulatory protein and global regulator, was shown to interact with Pat. We further demonstrate that Lrp could be acetylated by Pat and deacetylated by NAD+-dependent CobB in vitro. Specifically, the conserved lysine residue 36 (K36 in helix-turn-helix (HTH DNA-binding domain of Lrp was acetylated. Acetylation of K36 impaired the function of Lrp through altering the affinity with the target promoter. The mutation of K36 in chromosome mimicking acetylation enhanced the transcriptional level of itself and attenuated the mRNA levels of Lrp-regulated genes including fimA, which was confirmed by yeast agglutination assay. These findings demonstrate that the acetylation regulates the DNA-binding activity of Lrp, suggesting that acetylation modification of transcription factors is a conserved regulatory manner to modulate gene expression in bacteria and eukaryotes.

N-Acetyl-L-Leucine Accelerates Vestibular Compensation after Unilateral Labyrinthectomy by Action in the Cerebellum and Thalamus

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Xiong, Guoming; Potschka, Heidrun; Jahn, Klaus; Bartenstein, Peter; Brandt, Thomas; Dutia, Mayank; Dieterich, Marianne; Strupp, Michael; la Fougère, Christian; Zwergal, Andreas

2015-01-01

An acute unilateral vestibular lesion leads to a vestibular tone imbalance with nystagmus, head roll tilt and postural imbalance. These deficits gradually decrease over days to weeks due to central vestibular compensation (VC). This study investigated the effects of i.v. N-acetyl-DL-leucine, N-acetyl-L-leucine and N-acetyl-D-leucine on VC using behavioural testing and serial [18F]-Fluoro-desoxyglucose ([18F]-FDG)-μPET in a rat model of unilateral chemical labyrinthectomy (UL). Vestibular behavioural testing included measurements of nystagmus, head roll tilt and postural imbalance as well as sequential whole-brain [18F]-FDG-μPET was done before and on days 1,3,7 and 15 after UL. A significant reduction of postural imbalance scores was identified on day 7 in the N-acetyl-DL-leucine (p metabolism (rCGM) by means of μPET revealed that only N-acetyl-L-leucine but not N-acetyl-D-leucine caused a significant increase of rCGM in the vestibulocerebellum and a decrease in the posterolateral thalamus and subthalamic region on days 3 and 7. A similar pattern was found when comparing the effect of N-acetyl-L-leucine on rCGM in an UL-group and a sham UL-group without vestibular damage. In conclusion, N-acetyl-L-leucine improves compensation of postural symptoms after UL in a dose-dependent and specific manner, most likely by activating the vestibulocerebellum and deactivating the posterolateral thalamus. PMID:25803613

Isolation and characterization of a thermolysin peptide containing acetyllysine from enzymatically acetylated f2al histone

International Nuclear Information System (INIS)

Horiuchi, Kentaro; Fujimoto, Daisaburo

1973-01-01

Previous studies (vol. 72, 433, '72) in this laboratory showed that histone acetylase in the cytosol of calf thymus introduced acetyl groups primarily into the epsilon-amino groups of lysine residues in a histone fraction, f2al. In an attempt to examine the site of acetylation in f2al by the enzyme, 14 C-acetylated f2al was isolated and digested by thermolysin. A radioactive peptide, which accounted for 50 - 60% of the total radioactivity, was obtained from the thermolysin digest and identified as the fragment containing amino acid residues 10-21. It appears, therefore, that the major sites of acetylation by the enzyme are the lysine 12 or 16 or both, which are known to be acetylated in vivo. It was also shown that the peptide was not deacetylated by histone deacetylase, in contrast with the whole f2al molecule. (author)

Oral enclomiphene citrate stimulates the endogenous production of testosterone and sperm counts in men with low testosterone: comparison with testosterone gel.

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Kaminetsky, Jed; Werner, Michael; Fontenot, Greg; Wiehle, Ronald D

2013-06-01

Clomiphene citrate is employed off-label in men who have low testosterone and for the restoration of sperm counts in men who have used exogenous testosterone. Clomiphene is a mixture of two diastereoisomers: zuclomiphene and enclomiphene. We evaluated enclomiphene citrate in men with secondary hypogonadism. Our aim was to compare oral enclomiphene citrate as an alternative to topical testosterone. Blood levels of total testosterone (TT), estradiol, follicle-stimulating hormone (FSH), luteinizing hormone (LH), sex hormone binding globulin, thyroid stimulation hormone, prolactin, and insulin-like growth factor 1 IGF-1 were measured at certain times after treatment with each agent. Sperm parameters were determined at the same visits. Free testosterone (FT) was calculated. This was a proof-of-principle, randomized, open-label, fixed dose, active-control, two-center phase IIB study in 12 men with secondary hypogonadism treated previously with topical testosterone. After discontinuation of topical testosterone, morning TT values averaged 165 ± 66 pg/dL. After 3 months, there was a significant rise in men receiving enclomiphene citrate and gel that was sustained for 3 months. At 6 months, TT levels were 545 ± 268 and 525 ± 256 pg/dL for groups receiving the gel and enclomiphene citrate, respectively. Only men in the enclomiphene citrate group demonstrated increased LH and FSH. TT decreased one month posttreatment to pretreatment values. Enclomiphene citrate elevated sperm counts in seven out of seven men at 3 months and six out of six men at 6 months with sperm concentrations in the 75-334 × 10(6) /mL range. The gel was ineffective in raising sperm counts above 20 × 10(6) /mL for all five men at 3 months and raised counts in only two or five men at 6 months. At follow-up, only enclomiphene citrate treatment was associated with elevated sperm counts. Enclomiphene citrate increased testosterone and sperm counts. Concomitant changes in LH and FSH suggest normalization

Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

Science.gov (United States)

CAVASSIM, Rodrigo; LEITE, Fábio Renato Manzolli; ZANDIM, Daniela Leal; DANTAS, Andrea Abi Rached; RACHED, Ricardo Samih Georges Abi; SAMPAIO, José Eduardo Cezar

2012-01-01

Objective The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. Material and Methods A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group). After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. Results Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. Conclusion Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning. PMID:22858707

Influence of concentration, time and method of application of citric acid and sodium citrate in root conditioning

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Rodrigo Cavassim

2012-06-01

Full Text Available OBJECTIVES: The aim of this study was to establish the parameters of concentration, time and mode of application of citric acid and sodium citrate in relation to root conditioning. MATERIAL AND METHODS: A total of 495 samples were obtained and equally distributed among 11 groups (5 for testing different concentrations of citric acid, 5 for testing different concentrations of sodium citrate and 1 control group. After laboratorial processing, the samples were analyzed under scanning electron microscopy. A previously calibrated and blind examiner evaluated micrographs of the samples. Non-parametric statistical analysis was performed to analyze the data obtained. RESULTS: Brushing 25% citric acid for 3 min, promoted greater exposure of collagen fibers in comparison with the brushing of 1% citric acid for 1 minute and its topical application at 1% for 3 min. Sodium citrate exposed collagen fibers in a few number of samples. CONCLUSION: Despite the lack of statistical significance, better results for collagen exposure were obtained with brushing application of 25% citric acid for 3 min than with other application parameter. Sodium citrate produced a few number of samples with collagen exposure, so it is not indicated for root conditioning.

Synthesis and characterization of poly(glycerol citrate/sebacate)

International Nuclear Information System (INIS)

Brioude, Michel M.; Guimaraes, Danilo H.; Fiuza, Raigenis P.; Boaventura, Jaime S.; Jose, Nadia M.

2011-01-01

In this work were prepared and characterized the poly(glycerol citrate/sebacate) in three different ratios between acids. The polymers were prepared by a polycondensation reaction between glycerol and citric/sebacic acids and characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning differential calorimetry (DSC), scanning electron microscopy (SEM). The results showed that the polymers are polyesters and its crystallinity, thermal and morphological properties were modified by sebacic acid adding. (author)

EWSR1 regulates mitosis by dynamically influencing microtubule acetylation.

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Wang, Yi-Long; Chen, Hui; Zhan, Yi-Qun; Yin, Rong-Hua; Li, Chang-Yan; Ge, Chang-Hui; Yu, Miao; Yang, Xiao-Ming

2016-08-17

EWSR1, participating in transcription and splicing, has been identified as a translocation partner for various transcription factors, resulting in translocation, which in turn plays crucial roles in tumorigenesis. Recent studies have investigated the role of EWSR1 in mitosis. However, the effect of EWSR1 on mitosis is poorly understood. Here, we observed that depletion of EWSR1 resulted in cell cycle arrest in the mitotic phase, mainly due to an increase in the time from nuclear envelope breakdown to metaphase, resulting in a high percentage of unaligned chromosomes and multipolar spindles. We also demonstrated that EWSR1 is a spindle-associated protein that interacts with α-tubulin during mitosis. EWSR1 depletion increased the cold-sensitivity of spindle microtubules, and decreased the rate of spindle assembly. EWSR1 regulated the level of microtubule acetylation in the mitotic spindle; microtubule acetylation was rescued in EWSR1-depleted mitotic cells following suppression of HDAC6 activity by its specific inhibitor or siRNA treatment. In summary, these results suggest that EWSR1 regulates the acetylation of microtubules in a cell cycle-dependent manner through its dynamic location on spindle MTs, and may be a novel regulator for mitosis progress independent of its translocation.

Chromatin decondensed by acetylation shows an elevated radiation response

International Nuclear Information System (INIS)

Nackerdien, Z.; Michie, J.; Boehm, L.

1989-01-01

V-79 Chinese hamster lung fibroblasts exposed to 5 mM n-sodium butyrate were irradiated with 60Co gamma rays and cell survival was determined by the cell colony assay. In a separate set of experiments the acetylated chromatin obtained from these cells was irradiated and the change of molecular weight of the DNA was evaluated by alkaline sucrose density centrifugation. At a survival level of 10(-2) to 10(-4) cells exposed to butyrate were found to be 1.3-1.4 times more radiosensitive than control cells. Exposure of isolated chromatin to 100 Gy of 60Co gamma irradiation generated 0.9 +/- 0.03 single-strand breaks (ssb) per 10 Gy per 10(8) Da and 2.0 +/- 0.3 ssb/10 Gy/10(8) Da for control and acetylated chromatin, respectively. The elevated radiation sensitivity of chromatin relaxed by acetylation is in good agreement with previous results on chromatin expanded by histone H1 depletion. Packing and accessibility of DNA in chromatin appear to be major factors which influence the radiation sensitivity. The intrinsic radiation sensitivity of chromatin in various packing states is discussed in light of the variation of radiation sensitivity of whole cells in the cell cycle which incorporates repair

Nitric Oxide Modulates Histone Acetylation at Stress Genes by Inhibition of Histone Deacetylases1[OPEN

Science.gov (United States)

Mengel, Alexander; Ageeva, Alexandra; Durner, Jörg

2017-01-01

Histone acetylation, which is an important mechanism to regulate gene expression, is controlled by the opposing action of histone acetyltransferases and histone deacetylases (HDACs). In animals, several HDACs are subjected to regulation by nitric oxide (NO); in plants, however, it is unknown whether NO affects histone acetylation. We found that treatment with the physiological NO donor S-nitrosoglutathione (GSNO) increased the abundance of several histone acetylation marks in Arabidopsis (Arabidopsis thaliana), which was strongly diminished in the presence of the NO scavenger 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. This increase was likely triggered by NO-dependent inhibition of HDAC activity, since GSNO and S-nitroso-N-acetyl-dl-penicillamine significantly and reversibly reduced total HDAC activity in vitro (in nuclear extracts) and in vivo (in protoplasts). Next, genome-wide H3K9/14ac profiles in Arabidopsis seedlings were generated by chromatin immunoprecipitation sequencing, and changes induced by GSNO, GSNO/2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide or trichostatin A (an HDAC inhibitor) were quantified, thereby identifying genes that display putative NO-regulated histone acetylation. Functional classification of these genes revealed that many of them are involved in the plant defense response and the abiotic stress response. Furthermore, salicylic acid, which is the major plant defense hormone against biotrophic pathogens, inhibited HDAC activity and increased histone acetylation by inducing endogenous NO production. These data suggest that NO affects histone acetylation by targeting and inhibiting HDAC complexes, resulting in the hyperacetylation of specific genes. This mechanism might operate in the plant stress response by facilitating the stress-induced transcription of genes. PMID:27980017

The influence of N-terminal acetylation on micelle-induced conformational changes and aggregation of α-Synuclein.

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David Ruzafa

Full Text Available The biological function of α-Synuclein has been related to binding to lipids and membranes but these interactions can also mediate α-Synuclein aggregation, which is associated to Parkinson's disease and other neuropathologies. In brain tissue α-Synuclein is constitutively N-acetylated, a modification that plays an important role in its conformational propensity, lipid and membrane binding, and aggregation propensity. We studied the interactions of the lipid-mimetic SDS with N-acetylated and non-acetylated α-Synuclein, as well as their early-onset Parkinson's disease variants A30P, E46K and A53T. At low SDS/protein ratios α-Synuclein forms oligomeric complexes with SDS micelles with relatively low α-helical structure. These micellar oligomers can efficiently nucleate aggregation of monomeric α-Synuclein, with successive formation of oligomers, protofibrils, curly fibrils and mature amyloid fibrils. N-acetylation reduces considerably the rate of aggregation of WT α-Synuclein. However, in presence of any of the early-onset Parkinson's disease mutations the protective effect of N-acetylation against micelle-induced aggregation becomes impaired. At higher SDS/protein ratios, N-acetylation favors another conformational transition, in which a second type of α-helix-rich, non-aggregating oligomers become stabilized. Once again, the Parkinson's disease mutations disconnect the influence of N-acetylation in promoting this transition. These results suggest a cooperative link between the N-terminus and the region of the mutations that may be important for α-Synuclein function.

Acetylation of the pro-apoptotic factor, p53 in the hippocampus following cerebral ischemia and modulation by estrogen.

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Limor Raz

Full Text Available Recent studies demonstrate that acetylation of the transcription factor, p53 on lysine(373 leads to its enhanced stabilization/activity and increased susceptibility of cells to stress. However, it is not known whether acetylation of p53 is altered in the hippocampus following global cerebral ischemia (GCI or is regulated by the hormone, 17β-estradiol (17β-E(2, and thus, this study examined these issues.The study revealed that Acetyl p53-Lysine(373 levels were markedly increased in the hippocampal CA1 region after GCI at 3 h, 6 h and 24 h after reperfusion, an effect strongly attenuated by 17β-E(2. 17β-E(2 also enhanced interaction of p53 with the ubiquitin ligase, Mdm2, increased ubiquitination of p53, and induced its down-regulation, as well as attenuated elevation of the p53 transcriptional target, Puma. We also observed enhanced acetylation of p53 at a different lysine (Lys(382 at 3 h after reperfusion, and 17β-E(2 also markedly attenuated this effect. Furthermore, administration of an inhibitor of CBP/p300 acetyltransferase, which acetylates p53, was strongly neuroprotective of the CA1 region following GCI. In long-term estrogen deprived (LTED animals, the ability of 17β-E(2 to attenuate p53 acetylation was lost, and intriguingly, Acetyl p53-Lysine(373 levels were markedly elevated in sham (non-ischemic LTED animals. Finally, intracerebroventricular injections of Gp91ds-Tat, a specific NADPH oxidase (NOX2 inhibitor, but not the scrambled tat peptide control (Sc-Tat, attenuated acetylation of p53 and reduced levels of Puma following GCI.The studies demonstrate that p53 undergoes enhanced acetylation in the hippocampal CA1 region following global cerebral ischemia, and that the neuroprotective agent, 17β-E(2, markedly attenuates the ischemia-induced p53 acetylation. Furthermore, following LTED, the suppressive effect of 17β-E(2 on p53 acetylation is lost, and p53 acetylation increases in the hippocampus, which may explain previous

The heat of formation of the acetyl cation: a theoretical evaluation

Science.gov (United States)

Smith, Brian J.; Radom, Leo

1990-12-01

Ab initio molecular orbital calculations have been used to obtain the heat of formation of the acetyl cation. In one set of calculations, the reverse activation barrier for the production of acetyl cation from acetaldehyde has been shown to be significantly different zero and the value obtained (9.8 kJ mol-1 at 298 K) has been used to correct the [Delta]Hof298 (CH3CO+) value derived from appearance energy measurements. In a second set of calculations, [Delta]H°f298 (CH3CO+) has been obtained from the calculated heats of a number of reactions involving the acetyl cation together with experimental heats of formation for the species involved. The best theoretical estimate for [Delta]H°f298 (CH3CO+), obtained as a mean of results from the two approaches, is 658 kJ mol-1. The best theoretical estimate for [Delta]H°f0(CH3CO+), obtained in a similar manner, is 665 kJ mol-1.

Centrifugation protocols: tests to determine optimal lithium heparin and citrate plasma sample quality.

Science.gov (United States)

Dimeski, Goce; Solano, Connie; Petroff, Mark K; Hynd, Matthew

2011-05-01

Currently, no clear guidelines exist for the most appropriate tests to determine sample quality from centrifugation protocols for plasma sample types with both lithium heparin in gel barrier tubes for biochemistry testing and citrate tubes for coagulation testing. Blood was collected from 14 participants in four lithium heparin and one serum tube with gel barrier. The plasma tubes were centrifuged at four different centrifuge settings and analysed for potassium (K(+)), lactate dehydrogenase (LD), glucose and phosphorus (Pi) at zero time, poststorage at six hours at 21 °C and six days at 2-8°C. At the same time, three citrate tubes were collected and centrifuged at three different centrifuge settings and analysed immediately for prothrombin time/international normalized ratio, activated partial thromboplastin time, derived fibrinogen and surface-activated clotting time (SACT). The biochemistry analytes indicate plasma is less stable than serum. Plasma sample quality is higher with longer centrifugation time, and much higher g force. Blood cells present in the plasma lyse with time or are damaged when transferred in the reaction vessels, causing an increase in the K(+), LD and Pi above outlined limits. The cells remain active and consume glucose even in cold storage. The SACT is the only coagulation parameter that was affected by platelets >10 × 10(9)/L in the citrate plasma. In addition to the platelet count, a limited but sensitive number of assays (K(+), LD, glucose and Pi for biochemistry, and SACT for coagulation) can be used to determine appropriate centrifuge settings to consistently obtain the highest quality lithium heparin and citrate plasma samples. The findings will aid laboratories to balance the need to provide the most accurate results in the best turnaround time.

Interactions of acetylated histones with DNA as revealed by UV laser induced histone-DNA crosslinking

International Nuclear Information System (INIS)

Stefanovsky, V.Yu.; Dimitrov, S.I.; Angelov, D.; Pashev, I.G.

1989-01-01

The interaction of acetylated histones with DNA in chromatin has been studied by UV laser-induced crosslinking histones to DNA. After irradiation of the nuclei, the covalently linked protein-DNA complexes were isolated and the presence of histones in them demonstrated immunochemically. When chromatin from irradiated nuclei was treated with clostripain, which selectively cleaved the N-terminal tails of core histones, no one of them was found covalently linked to DNA, thus showing that crosslinking proceeded solely via the N-terminal regions. However, the crosslinking ability of the laser was preserved both upon physiological acetylation of histones, known to be restricted to the N-terminal tails, and with chemically acetylated chromatin. This finding is direct evidence that the postsynthetic histone acetylation does not release the N-terminal tails from interaction with DNA

Effects of acupuncture on the citrate and glucose metabolism in the liver under various types of stress

International Nuclear Information System (INIS)

Liao, Y.Y.; Seto, K.; Saito, H.; Kawakami, M.

1980-01-01

A study was made of the effect of acupuncture on citrate and glucose metabolism in the liver in terms of incorporation of 14 C-1, 5-citric acid and 14 C-u-glucose in some metabolites. The effect of acupuncture on citrate metabolism in the liver under control conditions was such as to increase production of G and reduce that of KB, FC and FFA. No effect of acupuncture on glucose metabolism in the liver under such conditions was observed. Both citrate and glucose metabolism were affected to a marked extent by immobilization stress or exposure to heat or cold. The deleterious effect of these types of stress was less prominent in animals receiving acupuncture at the Tsu-San-Li locus than in those treated otherwise or receiving no treatment

Influence of citrate ions as complexing agent for electrodeposition of CuInSe{sub 2} thin films

Energy Technology Data Exchange (ETDEWEB)

Chraibi, F. [Universite Libre de Bruxelles (Belgium). Service de Sciences des Materiaux et Electrochimie; Universite Mohammed 5, Rabat (Morocco). Dept. de Physique; Fahoume, M.; Ennaoui, A. [Universite Mohammed 5, Rabat (Morocco). Dept. de Physique; Delplancke, J.L. [Universite Libre de Bruxelles (Belgium). Service de Sciences des Materiaux et Electrochimie

2001-08-16

The preparation of CuInSe{sub 2} thin films by electrodeposition is studied. The effect of sodium citrate (Na{sub 3}C{sub 6}H{sub 5}O{sub 7}) as complexing agent on the electrodeposition of pure copper, indium, selenium and of their ternary alloy is emphasized. Cathodic shifts of the copper and selenium electrodeposition potentials with increasing citrate concentration are observed. On the contrary, the presence of citrate in the electrolyte does not change the indium electrodeposition potential but improves its crystallinity. The surface morphology and the composition of the deposited films are characterized by scanning electron microscopy (SEM). The texture of the deposits and their compositions are analyzed by X-ray diffraction. The formation of CuInSe{sub 2} films with a chalcopyrite structure and good stoichiometry is observed. (orig.)

Effects of acupuncture on the citrate and glucose metabolism in the liver under various types of stress

Energy Technology Data Exchange (ETDEWEB)

Liao, Y.Y.; Seto, K.; Saito, H.; Kawakami, M.

A study was made of the effect of acupuncture on citrate and glucose metabolism in the liver in terms of incorporation of /sup 14/C-1, 5-citric acid and /sup 14/C-u-glucose in some metabolites. The effect of acupuncture on citrate metabolism in the liver under control conditions was such as to increase production of G and reduce that of KB, FC and FFA. No effect of acupuncture on glucose metabolism in the liver under such conditions was observed. Both citrate and glucose metabolism were affected to a marked extent by immobilization stress or exposure to heat or cold. The deleterious effect of these types of stress was less prominent in animals receiving acupuncture at the Tsu-San-Li locus than in those treated otherwise or receiving no treatment.

Effects of Citrate and Arginine on Sorption of Nickel to Yazd Sepiolite and Calcite

Directory of Open Access Journals (Sweden)

Ahmadreza Sheikhhosseini

2017-03-01

Full Text Available Introduction: Pollution of soil and water environment by release of heavy metals is of great concerns of the last decades. Sorption of heavy metals by low cost materials is considered as an inexpensive and efficient method used for removal of heavy metals from soil-water systems. The presence of different ligands with various complexing abilities can change the sorption properties of heavy metals and their fate in the environment as well. In order to assess the effect of citrate and arginine as natural organic ligands in soil environment, in a batch study we investigated the effects of these ligands on equilibrium sorption of nickel to sepiolite and calcite minerals and also kinetics of Ni sorption by these minerals. Materials and Methods: Minerals used in this study included sepiolite from Yazd (Iran and pure calcite (Analytical grade, Merck, Germany. Sepiolite was purified, saturated with Ca using 0.5 M CaCl2, powdered in a mortar and sieved by non-metal 230 mesh standard wire sieve. For equilibrium sorption study, in a 50-mL polyethylene centrifuge tube,0.3 g sample of each mineral was suspended in 30 mL of a 0.01 M CaCl2 solution containing 0, 5, 10, 20, 40, 60, 80 and 100 mg L-1 Ni (NiCl2 and containing zero (as control or 0.1mmol L-1 citrate or arginine ligands. The applied concentrationsfor each ligand can naturally occur in soils. Preparedtubes were shaken (180±2 rpm, 25±1oC for 24 h using an orbital shaker and centrifuged (4000×g for 10 min and the supernatants were analyzed for Ni concentration using an atomic absorption spectrophotometer (AAnalyst 200 Perkin-Elmer at a wavelength of 232 nm and a detection limit of 0.05 mg L-1. The quantity of Ni retained by each mineral at equilibrium was calculated using equation qe = (Ci - CeV/W where qe was the amount of nickel retained by mineral surface at equilibrium. Ci and Ce were the initial and the equilibrium concentrations (mg L-1 of Ni, respectively, V was the volume (L of the solution

Structure and elevator mechanism of the Na(+)-citrate transporter CitS

NARCIS (Netherlands)

Lolkema, Juke S; Slotboom, Dirk Jan

2016-01-01

The recently determined crystal structure of the bacterial Na(+)-citrate symporter CitS provides unexpected structural and mechanistic insights. The protein has a fold that has not been seen in other proteins, but the oligomeric state, domain organization and proposed transport mechanism strongly

Capillary electrophoresis with indirect UV detection for the determination of stabilizers and citrates present in human albumin solutions.

Science.gov (United States)

Jaworska, Małgorzata; Cygan, Paulina; Wilk, Małgorzata; Anuszewska, Elzbieta

2009-08-15

Sodium caprylate and N-acetyltryptophan are the most frequently used stabilizers that protect the albumin from aggregation or heat induced denaturation. In turn citrates - excipients remaining after fractionation process - can be treated as by-product favoring leaching aluminum out of glass containers whilst albumin solution is stored. With ionic nature these substances have all the markings of a subject for capillary electrophoresis analysis. Thus CE methods were proposed as new approach for quality control of human albumin solution in terms of determination of stabilizers and citrates residue. Human albumin solutions both 5% and 20% from various manufacturers were tested. Indirect detection mode was set to provide sufficient detectability of analytes lacking of chromophores. As being anions analytes were separated with reversed electroosmotic flow. As a result of method optimization two background electrolytes based on p-hydroxybenzoic acid and 2,6-pyridinedicarboxylic acid were selected for stabilizers and citrates separation, respectively. The optimized methods were successfully validated. For citrates that require quantification below 100microM the method demonstrated the precision less than 4% and the limit of detection at 4microM. In order to check the new methods accuracy and applicability the samples were additionally tested with selected reference methods. The proposed methods allow reliable quantification of stabilizers and citrates in human albumin solution that was confirmed by method validation as well as result comparison with reference methods. The CE methods are considered to be suitable for quality control yet simplifying and reducing cost of analysis.

Rapid Quantification of Low-Viscosity Acetyl-Triacylglycerols Using Electrospray Ionization Mass Spectrometry.

Science.gov (United States)

Bansal, Sunil; Durrett, Timothy P

2016-09-01

Acetyl-triacylglycerols (acetyl-TAG) possess an sn-3 acetate group, which confers useful chemical and physical properties to these unusual triacylglycerols (TAG). Current methods for quantification of acetyl-TAG are time consuming and do not provide any information on the molecular species profile. Electrospray ionization mass spectrometry (ESI-MS)-based methods can overcome these drawbacks. However, the ESI-MS signal intensity for TAG depends on the aliphatic chain length and unsaturation index of the molecule. Therefore response factors for different molecular species need to be determined before any quantification. The effects of the chain length and the number of double-bonds of the sn-1/2 acyl groups on the signal intensity for the neutral loss of short chain length sn-3 groups were quantified using a series of synthesized sn-3 specific structured TAG. The signal intensity for the neutral loss of the sn-3 acyl group was found to negatively correlated with the aliphatic chain length and unsaturation index of the sn-1/2 acyl groups. The signal intensity of the neutral loss of the sn-3 acyl group was also negatively correlated with the size of that chain. Further, the position of the group undergoing neutral loss was also important, with the signal from an sn-2 acyl group much lower than that from one located at sn-3. Response factors obtained from these analyses were used to develop a method for the absolute quantification of acetyl-TAG. The increased sensitivity of this ESI-MS-based approach allowed successful quantification of acetyl-TAG in various biological settings, including the products of in vitro enzyme activity assays.

Mangifera indica L. extract (Vimang) inhibits Fe2+-citrate-induced lipoperoxidation in isolated rat liver mitochondria.

Science.gov (United States)

Pardo Andreu, Gilberto; Delgado, René; Velho, Jesus; Inada, Natalia M; Curti, Carlos; Vercesi, Anibal E

2005-05-01

The extract of Mangifera indica L. (Vimang) is able to prevent iron mediated mitochondrial damage by means of oxidation of reduced transition metals required for the production of superoxide and hydroxyl radicals and direct free radical scavenging activity. In this study we report for the first time the iron-complexing ability of Vimang as a primary mechanism for protection of rat liver mitochondria against Fe2+ -citrate-induced lipoperoxidation. Thiobarbituric acid reactive substances (TBARS) and antimycin A-insensitive oxygen consumption were used as quantitative measures of lipoperoxidation. Vimang at 10 microM mangiferin concentration equivalent induced near-full protection against 50 microM Fe2+ -citrate-induced mitochondrial swelling and loss of mitochondrial transmembrane potential (DeltaPsi). The IC50 value for Vimang protection against Fe2+ -citrate-induced mitochondrial TBARS formation (7.89+/-1.19 microM) was around 10 times lower than that for tert-butylhydroperoxide mitochondrial induction of TBARS formation. The extract also inhibited the iron citrate induction of mitochondrial antimycin A-insensitive oxygen consumption, stimulated oxygen consumption due to Fe2+ autoxidation and prevented Fe3+ ascorbate reduction. The extracted polyphenolic compound, mainly mangiferin, could form a complex with Fe2+, accelerating Fe2+ oxidation and the formation of more stable Fe3+ -polyphenol complexes, unable to participate in Fenton-type reactions and lipoperoxidation propagation phase. The strong DPPH radical scavenging activity with an apparent IC50 of 2.45+/-0.08 microM suggests that besides its iron-complexing capacity, Vimang could also protect mitochondria from Fe2+ -citrate lipoperoxidation through direct free radical scavenging ability, mainly lipoperoxyl and alcoxyl radicals, acting as both a chain-breaking and iron-complexing antioxidant. These results are of pharmacological relevance since Vimang could be a potential candidate for antioxidant therapy in

Determining the chemical exchange saturation transfer (CEST) behavior of citrate and spermine under in vivo conditions

Science.gov (United States)

Basharat, Meer; deSouza, Nandita M.; Parkes, Harold G.

2015-01-01

Purpose To estimate the exchange rates of labile 1H in citrate and spermine, metabolites present in prostatic secretions, to predict the size of the citrate and spermine CEST effects in vivo. Methods CEST z‐spectra were acquired at high‐field [11.7 Tesla (T)] from citrate and spermine solutions at physiological pH (6.5) using saturation power 6 μT. CEST was performed at different temperatures to determine exchange regimes (slow, intermediate or fast). For low pH solutions of spermine, exchange rates were estimated from resonance line width, fitting z‐spectra using the Bloch equations incorporating exchange, and using quantifying exchange using saturation time experiments (QUEST). These rates were extrapolated to physiological pH. Results Citrate showed little CEST effect at pH 6.5 and temperature (T) = 310 K (maximum 0.001% mM‐1), indicating fast exchange, whereas spermine showed greater CEST effects (maximum 0.2% mM‐1) indicating intermediate‐to‐fast exchange. Extrapolating data acquired from low pH spermine solutions predicts exchange rates at pH 6.5 and T of 310 K of at least 2 × 104s‐1. Conclusion Citrate and spermine show minimal CEST effects at 11.7T even using high saturation power. These effects would be much less than 2% at clinical field‐strengths due to relatively faster exchange and would be masked by CEST from proteins. Magn Reson Med 76:742–746, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:26467055

Indirect flow injection determination of N-acetyl-L-cysteine using cerium(IV) and ferroin

International Nuclear Information System (INIS)

Vieira, Heberth Juliano; Fatibello-Filho, Orlando

2005-01-01

An indirect flow injection spectrophotometric procedure is proposed for the determination of N-acetyl-L-cysteine in pharmaceutical formulations. In this system, ferroin ([Fe(II)-(fen) 2 ] 2+ ) in excess, with a strong absorption at 500 nm, is oxidized by cerium(IV) yielding cerium(III) and [Fe(III)-(fen) 2 ] 3+ (colorless), thus producing a baseline. When N-acetyl-L-cysteine solution is introduced into the flow injection system, it reacts with cerium(IV) increasing the analytical signal in proportion to the drug concentration. Under optimal experimental conditions, the linearity of the analytical curve for N-acetyl-L-cysteine ranged from 6.5x10 -6 to 1.3x10 -4 mol L -1 . The detection limit was 5.0x10 -6 mol L -1 and recoveries between 98.0 and 106% were obtained. The sampling frequency was 60 determinations per hour and the RSD was smaller than 1.4% for 2.2x10 -5 mol L -1 N-acetyl-L-cysteine. (author)

Does adding metformin to clomifene citrate lead to higher pregnancy rates in a subset of women with polycystic ovary syndrome?

NARCIS (Netherlands)

Moll, E.; Korevaar, J. C.; Bossuyt, P. M. M.; van der Veen, F.

2008-01-01

BACKGROUND: An RCT among newly diagnosed, therapy naive women with polycystic ovary syndrome (PCOS) showed no significant differences in ovulation rate, ongoing pregnancy rate or spontaneous abortion rate in favour of clomifene citrate plus metformin compared with clomifene citrate. We wanted to

Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

Energy Technology Data Exchange (ETDEWEB)

Yang, Xiupei, E-mail: xiupeiyang@163.com [Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, Nanchong 637000 (China); College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000 (China); Lin, Jia; Liao, Xiulin; Zong, Yingying; Gao, Huanhuan [College of Chemistry and Chemical Engineering, China West Normal University, Nanchong 637000 (China)

2015-06-15

Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH{sub 3}{sup +} moiety of doxorubicin and the −COO{sup −} moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum.

Interactions between N-acetyl-L-cysteine protected CdTe quantum dots and doxorubicin through spectroscopic method

International Nuclear Information System (INIS)

Yang, Xiupei; Lin, Jia; Liao, Xiulin; Zong, Yingying; Gao, Huanhuan

2015-01-01

Highlights: • CdTe quantum dots with the diameter of 3–5 nm were synthesized in aqueous solution. • The modified CdTe quantum dots showed well fluorescence properties. • The interaction between the CdTe quantum dots and doxorubicin (DR) was investigated. - Abstract: N-acetyl-L-cysteine protected cadmium telluride quantum dots with a diameter of 3–5 nm were synthesized in aqueous solution. The interaction between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin was investigated by ultraviolet–visible absorption and fluorescence spectroscopy at physiological conditions (pH 7.2, 37 °C). The results indicate that electron transfer has occurred between N-acetyl-L-cysteine/cadmium telluride quantum dots and doxorubicin under light illumination. The quantum dots react readily with doxorubicin to form a N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex via electrostatic attraction between the −NH 3 + moiety of doxorubicin and the −COO − moiety of N-acetyl-L-cysteine/cadmium telluride quantum dots. The interaction of N-acetyl-L-cysteine/cadmium telluride-quantum dots/doxorubicin complex with bovine serum albumin was studied as well, showing that the complex might induce the conformation change of bovine serum due to changes in microenvironment of bovine serum

Monitoring the effect of belinostat in solid tumors by H4 acetylation

DEFF Research Database (Denmark)

Marquard, L.; Petersen, K.D.; Persson, M.

2008-01-01

after treatment with HDAC inhibitors, and could thus be used as a marker for monitoring cellular response to HDAC inhibitor treatment. Here we describe the utility of a newly described monoclonal antibody against acetylated H4 for immunohistochemistry on paraffin-embedded fine needle biopsies from nude...... acetylation in fine needle biopsies using the T25 antibody may prove useful in monitoring HDAC inhibitor efficacy in clinical trials involving humans with solid tumors Udgivelsesdato: 2008/5...

A proteome-scale study on in vivo protein Nα-acetylation using an optimized method

DEFF Research Database (Denmark)

Zhang, Xumin; Ye, Juanying; Engholm-Keller, Kasper

2011-01-01

Protein N-terminal acetylation (N(α) -acetylation) is among the most common modifications in eukaryotes. We previously described a simple method to enrich N(α) -modified peptides using CNBr-activated Sepharose resin. A limitation of this method is that an optimal ratio of sample to resin had to b...

Evaluation of the Effects of Sildenafil Citrate (Viagra) on Vertebral Artery Blood Flow in Patients with Vertebro-Basilar Insufficiency

International Nuclear Information System (INIS)

Bozgeyik, Zulkif; Berilgen, Sait; Ozdemir, Huseyin; Ogur, Erkin; Tekatas, Aslan

2008-01-01

To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS). The study included 21 patients with VBI (aged 31-76; mean 61.0 ± 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test. Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm 2 to 10.80 cm 2 at 45 minutes and 10.81 cm 2 at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively. Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs

Evaluation of the effects of sildenafil citrate (viagra) on vertebral artery blood flow in patients with vertebro-basilar insufficiency.

Science.gov (United States)

Bozgeyik, Zulkif; Berilgen, Sait; Ozdemir, Huseyin; Tekatas, Aslan; Ogur, Erkin

2008-01-01

To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS). The study included 21 patients with VBI (aged 31-76; mean 61.0 +/- 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test. Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm(2) to 10.80 cm(2) at 45 minutes and 10.81 cm(2) at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively. Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs.

Evaluation of the Effects of Sildenafil Citrate (Viagra) on Vertebral Artery Blood Flow in Patients with Vertebro-Basilar Insufficiency

Energy Technology Data Exchange (ETDEWEB)

Bozgeyik, Zulkif; Berilgen, Sait; Ozdemir, Huseyin; Ogur, Erkin [Firat University School of Medicine, Elazig(Turkmenistan); Tekatas, Aslan [Elazig Government Hospital, Elazig (Turkmenistan)

2008-12-15

To investigate the effects of sildenafil citrate (Viagra) on the vertebral artery blood flow of patients with vertebro-basilar insufficiency (VBI) using color duplex sonography (CDS). The study included 21 patients with VBI (aged 31-76; mean 61.0 +- 10.5 yrs). We administered a 50 mg oral dose of sildenafil citrate to all patients. Next, we measured the peak systolic velocity (Vmax), end diastolic velocity (Vmin), resistive index (RI), pulsatility index (PI), diameter, area, and flow volume (FV) of vertebral arteries using CDS before the administration of sildenafil citrate; 45 minutes after, and 75 minutes after administration. Statistical testing was performed using SPSS for windows version 11.0. The statistical test used to determine the outcome of the analysis was the repeated measures analysis of variance (ANOVA) test. Compared to the baseline values, the vertebral artery diameter, area, and FV increased significantly following the administration of sildenafil citrate. The diameter, area and FV increased from 3.39 mm at 45 minutes to 3.64 mm at 75 minutes, 9.43 cm{sup 2} to 10.80 cm{sup 2} at 45 minutes and 10.81 cm{sup 2} at 75 minutes, as well as from 0.07 L/min at baseline to 0.09 L/min at 45 minutes and unchanged at 75 minutes, respectively. Sildenafil citrate elicited a significant effect on vertebral artery diameter, area and FVs

Cost-effectiveness of treatment strategies in women with PCOS who do not conceive after six cycles of clomiphene citrate.

Science.gov (United States)

Moolenaar, Lobke M; Nahuis, Marleen J; Hompes, Peter G; van der Veen, Fulco; Mol, Ben Willem J

2014-05-01

This study evaluated the cost-effectiveness of treatments for women with polycystic ovary syndrome (PCOS) who ovulate on clomiphene citrate but do not conceive after six cycles. A decision-analytic framework was developed for six scenarios: (1) three cycles of IVF; (2) continuation of clomiphene citrate for six cycles, followed by three cycles of IVF in case of no birth; (3) six cycles of gonadotrophins and three cycles of IVF; (4) 12 cycles of gonadotrophins and three cycles of IVF; (5) continuation of clomiphene citrate for six cycles, six cycles of gonadotrophins and three cycles of IVF; (6) continuation of clomiphene citrate for six cycles, 12 cycles of gonadotrophins and three cycles of IVF. Two-year cumulative birth rates were 58%, 74%, 89%, 97%, 93% and 98% and costs per couple were € 9518, € 7530, € 9711, € 9764, € 7651 and € 7684 for scenarios 1-6, respectively. Scenario 2 was the lowest cost option. The extra cost for at least one live birth in scenario 5 was € 629 and in scenario 6 € 630. In these subjects, continuation of treatment for six cycles of clomiphene citrate, 6 or 12 cycles of gonadotrophins and IVF is potentially cost-effective. These results should be confirmed in a randomized clinical trial. Copyright © 2014 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

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

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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.

Inhibition of p53 acetylation by INHAT subunit SET/TAF-Iβ represses p53 activity.

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Kim, Ji-Young; Lee, Kyu-Sun; Seol, Jin-Ee; Yu, Kweon; Chakravarti, Debabrata; Seo, Sang-Beom

2012-01-01

The tumor suppressor p53 responds to a wide variety of cellular stress signals. Among potential regulatory pathways, post-translational modifications such as acetylation by CBP/p300 and PCAF have been suggested for modulation of p53 activity. However, exactly how p53 acetylation is modulated remains poorly understood. Here, we found that SET/TAF-Iβ inhibited p300- and PCAF-mediated p53 acetylation in an INHAT (inhibitor of histone acetyltransferase) domain-dependent manner. SET/TAF-Iβ interacted with p53 and repressed transcription of p53 target genes. Consequently, SET/TAF-Iβ blocked both p53-mediated cell cycle arrest and apoptosis in response to cellular stress. Using different apoptosis analyses, including FACS, TUNEL and BrdU incorporation assays, we also found that SET/TAF-Iβ induced cellular proliferation via inhibition of p53 acetylation. Furthermore, we observed that apoptotic Drosophila eye phenotype induced by either dp53 overexpression or UV irradiation was rescued by expression of dSet. Inhibition of dp53 acetylation by dSet was observed in both cases. Our findings provide new insights into the regulation of stress-induced p53 activation by HAT-inhibiting histone chaperone SET/TAF-Iβ.

THE SURFACE PHOTOCHEMISTRY OF PROCYMIDONE IN PRESENCE OF AMMONIUM FERRIC CITRATE

Directory of Open Access Journals (Sweden)

Ivan Osipov

2015-12-01

Full Text Available Procymidone was chosen as the model compound and its phototransformation was followed under sunlight irradiation. The main photodegradation products on silica is 3,5-dichloroaniline and 3,5-diclorphenilisocyanate. The use of ammonium ferric citrate enhances the degradation of the procymidone.

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

Directory of Open Access Journals (Sweden)

Thomas A

2014-05-01

Full Text Available Anila Thomas,1 Leif E Peterson2 1Clinical Pharmacy Services, Houston Methodist Hospital, Houston, TX, USA; 2Center for Biostatistics, Houston Methodist Research Institute, Houston, TX, USA 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. Keywords

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

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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

Chloride content of solutions used for regional citrate anticoagulation might be responsible for blunting correction of metabolic acidosis during continuous veno-venous hemofiltration.

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Jacobs, Rita; Honore, Patrick M; Diltoer, Marc; Spapen, Herbert D

2016-08-26

Citrate, the currently preferred anticoagulant for continuous veno-venous hemofiltration (CVVH), may influence acid-base equilibrium. The effect of 2 different citrate solutions on acid-base status was assessed according to the Stewart-Figge approach in two consecutive cohorts of critically ill adult patients. The first group received Prismocitrate 10/2 (PC10/2; 10 mmol citrate/L). The next group was treated with Prismocitrate 18/0 (PC18; 18 mmol citrate/L). Both groups received bicarbonate-buffered fluids in post-dilution. At similar citrate flow, the metabolic acidosis present at baseline in both groups was significantly attenuated in PC18 patients but persisted in PC10/2 patients after 24 h of treatment (median pH 7,42 vs 7,28; p = 0.0001). Acidosis in the PC10/2 group was associated with a decreased strong ion difference and an increased strong ion gap (respectively 43 vs. 51 mmol/L and 17 vs. 12 mmol/L, PC10/2 vs. PC18; both p = 0.001). Chloride flow was higher in PC10/2 than in PC18 subjects (25.9 vs 14.3 mmol/L blood; p < 0.05). Correction of acidosis was blunted in patients who received 10 mmol citrate/L as regional anticoagulation during CVVH. This could be explained by differences in chloride flow between the applied citrate solutions inducing hyperchloremic acidosis.

Volumetric and isentropic compressibility behaviour of aqueous solutions of (polyvinylpyrrolidone + sodium citrate) at T = (283.15 to 308.15) K

International Nuclear Information System (INIS)

Sadeghi, Rahmat; Ziamajidi, Fatemeh

2007-01-01

The apparent specific volumes and isentropic compressibilities have been determined for polyvinylpyrrolidone in aqueous solutions of sodium citrate by density and sound velocity measurements at T = (283.15 to 308.15) K at atmospheric pressure. The results show a positive transfer volume of PVP from an aqueous solution to an aqueous sodium citrate solution. For low concentrations of PVP, the apparent specific volumes of PVP in water increased along with an increase in the polymer mass fraction, while in aqueous sodium citrate solutions decreased along with an increase in the polymer mass fraction. For high concentrations of PVP, the apparent specific volumes of PVP in water and in aqueous sodium citrate solutions were independent of the polymer mass fraction. The apparent specific isentropic compressibility of PVP is negative at T = (283.15 and 288.15) K, which imply that the water molecules around the PVP molecules are less compressible than the water molecules in the bulk solutions. The positive values of apparent specific isentropic compressibility at T = (298.15, 303.15, and 308.15) K imply that the water molecules around the PVP molecules are more compressible than the water molecules in the bulk solutions. Finally, it was found that the apparent specific isentropic compressibility of PVP increases as the concentration of sodium citrate increases

Inkjet printing of silver citrate conductive ink on PET substrate

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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.

Interactions between citrate-capped gold nanoparticles and polymersomes

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Zhang, Xiaohan; Lopez, Anand; Liu, Yibo; Wang, Feng; Liu, Juewen

2018-06-01

Polymersomes are vesicles formed by self-assembled amphiphilic block copolymers. Polymersomes generally have better stability than liposomes and they have been widely used in making drug delivery vehicles. In this work, the interaction between two types of polymersomes and citrate-capped gold nanoparticles (AuNPs) was studied. The following two polymers: poly(2-methyloxazoline-b-dimethylsiloxane-b-2-methyloxazoline) (called P1) and poly(butadiene-b-ethylene oxide) (called P2) were respectively used to form polymersomes. While P1 only formed spherical vesicle structures, worm-like structures were also observed with P2 as indicated by cryo-TEM. Both polymersomes adsorbed AuNPs leading to their subsequent aggregation. A lower polymersome concentration produced more obvious aggregation of AuNPs as judged from the color change. Capping AuNPs with glutathione inhibited adsorption of AuNPs. Considering the surface property of the polymers, the interaction with AuNPs was likely due to van der Waals forces. P1 polymersomes encapsulated calcein stably and AuNPs did not induce leakage. The P1/AuNP complex was more efficiently internalized by HeLa cells compared to free P1 polymersomes, further indicating a stable adsorption under cell culture conditions. In summary, this work indicates citrate-capped AuNPs form stable adsorption complexes with these polymersomes and their interactions have been explored.

A study on 99Tcm-citrate and 99Tcm (V)-DMSA imaging in the diagnosis of acute purulent osteoarthritis