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Sample records for inhibit sodium antimony

  1. Inhibition of ABC Transporters Abolishes Antimony Resistance in Leishmania Infection▿

    PubMed Central

    Mookerjee Basu, Jayati; Mookerjee, Ananda; Banerjee, Rajdeep; Saha, Manik; Singh, Subhankar; Naskar, Ksudiram; Tripathy, Gayetri; Sinha, Prabhat K.; Pandey, Krishna; Sundar, Shyam; Bimal, Sanjeev; Das, Pradip K.; Choudhuri, Soumitra K.; Roy, Syamal

    2008-01-01

    The emergence of antimony (Sb) resistance has jeopardized the treatment of visceral leishmaniasis in various countries. Previous studies have considered the part played by leishmanial parasites in antimony resistance, but the involvement of host factors in the clinical scenario remained to be investigated. Here we show that unlike infection with Sb-sensitive (Sbs) Leishmania donovani, infection with Sb-resistant (Sbr) L. donovani induces the upregulation of multidrug resistance-associated protein 1 (MRP1) and permeability glycoprotein (P-gp) in host cells, resulting in a nonaccumulation of intracellular Sb following treatment with sodium antimony gluconate (SAG) favoring parasite replication. The inhibition of MRP1 and P-gp with resistance-modifying agents such as lovastatin allows Sb accumulation and parasite killing within macrophages and offers protection in an animal model in which infection with Sbr L. donovani is otherwise lethal. The occurrence of a similar scenario in clinical cases is supported by the findings that unlike monocytes from SAG-sensitive kala-azar (KA) patients, monocytes from SAG-unresponsive KA patients overexpress P-gp and MRP1 and fail to accumulate Sb following in vitro SAG treatment unless pretreated with inhibitors of ABC transporters. Thus, the expression status of MRP1 and P-gp in blood monocytes may be used as a diagnostic marker for Sb resistance and the treatment strategy can be designed accordingly. Our results also indicate that lovastatin, which can inhibit both P-gp and MRP1, might be beneficial for reverting Sb resistance in leishmaniasis as well as drug resistance in other clinical situations, including cancer. PMID:18056276

  2. Antimony

    Integrated Risk Information System (IRIS)

    Antimony ; CASRN 7440 - 36 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effects

  3. Antimony tartrate corrosion inhibitive composition for coolant systems

    SciTech Connect

    Payerle, N.E.

    1987-08-11

    An automobile coolant concentrate is described comprising (a) a liquid polyhydric alcohol chosen from the group consisting of ethylene glycol, propylene glycol, diethylene glycol and mixtures thereof, and (b) corrosion inhibitors in a corrosion inhibitory amount with respect to corrosion of lead-containing solders, the corrosion inhibitors comprising (i) an alkali metal antimony tartrate, and (ii) an azole compound.

  4. Antimony nanoparticles anchored in three-dimensional carbon network as promising sodium-ion battery anode

    NASA Astrophysics Data System (ADS)

    Luo, Wen; Zhang, Pengfei; Wang, Xuanpeng; Li, Qidong; Dong, Yifan; Hua, Jingchen; Zhou, Liang; Mai, Liqiang

    2016-02-01

    A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g-1 at 100 mA g-1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g-1) as well as superior rate capability (270 mAh g-1 at 2000 mA g-1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next "beyond lithium" battery generation.

  5. Reduced Graphene Oxide/Tin-Antimony Nanocomposites as Anode Materials for Advanced Sodium-Ion Batteries.

    PubMed

    Ji, Liwen; Zhou, Weidong; Chabot, Victor; Yu, Aiping; Xiao, Xingcheng

    2015-11-11

    Reduced graphene oxides loaded with tin-antimony alloy (RGO-SnSb) nanocomposites were synthesized through a hydrothermal reaction and the subsequent thermal reduction treatments. Transmission electron microscope images confirm that SnSb nanoparticles with an average size of about 20-30 nm are uniformly dispersed on the RGO surfaces. When they were used as anodes for rechargeable sodium (Na)-ion batteries, these as-synthesized RGO-SnSb nanocomposite anodes delivered a high initial reversible capacity of 407 mAh g(-1), stable cyclic retention for more than 80 cycles and excellent cycle stability at ultra high charge/discharge rates up to 30C. The significantly improved performance of the synthesized RGO-SnSb nanocomposites as Na-ion battery anodes can be attributed to the synergetic effects of RGO-based flexible framework and the nanoscale dimension of the SnSb alloy particles (<30 nm). Nanosized intermetallic SnSb compounds can exhibit improved structural stability and conductivity during charge and discharge reactions compared to the corresponding individuals (Sn and Sb particles). In the meantime, RGO sheets can tightly anchor SnSb alloy particles on the surfaces, which can not only effectively suppress the agglomeration of SnSb particles but also maintain excellent electronic conduction. Furthermore, the mechanical flexibility of the RGO phase can accommodate the volume expansion and contraction of SnSb particles during the prolonged cycling, therefore, improve the electrode integrity mechanically and electronically. All of these contribute to the electrochemical performance improvements of the RGO-SnSb nanocomposite-based electrodes in rechargeable Na-ion batteries.

  6. Co-administration of glycyrrhizic acid with the antileishmanial drug sodium antimony gluconate (SAG) cures SAG-resistant visceral leishmaniasis.

    PubMed

    Bhattacharjee, Amrita; Majumder, Saikat; Majumdar, Suchandra Bhattacharyya; Choudhuri, Soumitra Kumar; Roy, Syamal; Majumdar, Subrata

    2015-03-01

    Since there are very few affordable antileishmanial drugs available, antimonial resistance has crippled antileishmanial therapy, thereby emphasising the need for development of novel therapeutic strategies. This study aimed to evaluate the antileishmanial role of combined therapy with sodium antimony gluconate (SAG) and the triterpenoid glycyrrhizic acid (GA) against infection with SAG-resistant Leishmania (GE1F8R). Combination therapy with GA and SAG successfully limited infection with SAG-resistant Leishmania in a synergistic manner (fractional inhibitory concentration index <1.0). At the same time, mice infected with SAG-resistant Leishmania and co-treated with GA and SAG exhibited a significant reduction in hepatic and splenic parasite burden. In probing the mechanism, it was observed that GA treatment suppressed the expression and efflux activity of P-glycoprotein (P-gp) and multidrug resistance-associated protein 1 (MRP1), two host ABC transporters responsible for antimony efflux from host cells infected with SAG-resistant parasites. This suppression correlated with greater intracellular antimony retention during SAG therapy both in vitro and in vivo, which was reflected in the reduced parasite load. Furthermore, co-administration of GA and SAG induced a shift in the cytokine balance towards a Th1 phenotype by augmenting pro-inflammatory cytokines (such as IL-12, IFNγ and TNFα) and inducing nitric oxide generation in GE1F8R-infected macrophages as well as GE1F8R-infected mice. This study aims to provide an affordable leishmanicidal alternative to expensive antileishmanial drugs such as miltefosine and amphotericin B. Furthermore, this report explores the role of GA as a resistance modulator in MRP1- and P-gp-overexpressing conditions.

  7. High-capacity antimony sulphide nanoparticle-decorated graphene composite as anode for sodium-ion batteries.

    PubMed

    Yu, Denis Y W; Prikhodchenko, Petr V; Mason, Chad W; Batabyal, Sudip K; Gun, Jenny; Sladkevich, Sergey; Medvedev, Alexander G; Lev, Ovadia

    2013-01-01

    Sodium-ion batteries are an alternative to lithium-ion batteries for large-scale applications. However, low capacity and poor rate capability of existing anodes are the main bottlenecks to future developments. Here we report a uniform coating of antimony sulphide (stibnite) on graphene, fabricated by a solution-based synthesis technique, as the anode material for sodium-ion batteries. It gives a high capacity of 730 mAh g(-1) at 50 mA g(-1), an excellent rate capability up to 6C and a good cycle performance. The promising performance is attributed to fast sodium ion diffusion from the small nanoparticles, and good electrical transport from the intimate contact between the active material and graphene, which also provides a template for anchoring the nanoparticles. We also demonstrate a battery with the stibnite-graphene composite that is free from sodium metal, having energy density up to 80 Wh kg(-1). The energy density could exceed that of some lithium-ion batteries with further optimization.

  8. Sodium Channel Inhibiting Marine Toxins

    NASA Astrophysics Data System (ADS)

    Llewellyn, Lyndon E.

    Saxitoxin (STX), tetrodotoxin (TTX) and their many chemical relatives are part of our daily lives. From killing people who eat seafood containing these toxins, to being valuable research tools unveiling the invisible structures of their pharmacological receptor, their global impact is beyond measure. The pharmacological receptor for these toxins is the voltage-gated sodium channel which transports Na ions between the exterior to the interior of cells. The two structurally divergent families of STX and TTX analogues bind at the same location on these Na channels to stop the flow of ions. This can affect nerves, muscles and biological senses of most animals. It is through these and other toxins that we have developed much of our fundamental understanding of the Na channel and its part in generating action potentials in excitable cells.

  9. Inhaled sodium metabisulphite induced bronchoconstriction: inhibition by nedocromil sodium and sodium cromoglycate.

    PubMed Central

    Dixon, C M; Ind, P W

    1990-01-01

    1. The effects of nedocromil sodium and sodium cromoglycate on bronchoconstriction induced by inhaled sodium metabisulphite have been studied in eight atopic subjects, three of whom had mild asthma. 2. Nedocromil sodium (4 mg, 7.8 X 10(-6) M), sodium cromoglycate (10 mg, 24.1 X 10(-6) M) and matched placebo were administered by identical metered dose inhalers 30 min before a dose-response to sodium metabisulphite (5-100 mg ml-1) was performed. 3. Maximum fall in sGaw after placebo pre-treatment was -43.9 +/- 3.3% baseline (mean +/- s.e. mean). At the same metabisulphite concentration maximum fall in sGaw after sodium cromoglycate was -13.0 +/- 3.6% and after nedocromil sodium was +4.3 +/- 6.8%. Nedocromil sodium prevented any significant fall in sGaw even after higher concentrations of metabisulphite. 4. Both nedocromil sodium, 4 mg, and sodium cromoglycate, 10 mg, inhibited sodium metabisulphite induced bronchoconstriction but nedocromil sodium was significantly more effective. Relative in vivo potency of the two drugs is broadly in line with other in vivo and in vitro studies. PMID:2171616

  10. Inhibition Of Washed Sludge With Sodium Nitrite

    SciTech Connect

    Congdon, J. W.; Lozier, J. S.

    2012-09-25

    This report describes the results of electrochemical tests used to determine the relationship between the concentration of the aggressive anions in washed sludge and the minimum effective inhibitor concentration. Sodium nitrate was added as the inhibitor because of its compatibility with the DWPF process. A minimum of 0.05M nitrite is required to inhibit the washed sludge simulant solution used in this study. When the worst case compositions and safety margins are considered, it is expected that a minimum operating limit of nearly 0.1M nitrite will be specified. The validity of this limit is dependent on the accuracy of the concentrations and solubility splits previously reported. Sodium nitrite additions to obtain 0.1M nitrite concentrations in washed sludge will necessitate the additional washing of washed precipitate in order to decrease its sodium nitrite inhibitor requirements sufficiently to remain below the sodium limits in the feed to the DWPF. Nitrite will be the controlling anion in "fresh" washed sludge unless the soluble chloride concentration is about ten times higher than predicted by the solubility splits. Inhibition of "aged" washed sludge will not be a problem unless significant chloride dissolution occurs during storage. It will be very important tomonitor the composition of washed sludge during processing and storage.

  11. Ultrafast and Highly Reversible Sodium Storage in Zinc-Antimony Intermetallic Nanomaterials

    SciTech Connect

    Nie, Anmin; Gan, Li-yong; Cheng, Yingchun; Tao, Xinyong; Yuan, Yifei; Sharifi-Asl, Soroosh; He, Kun; Asayesh-Ardakani, Hasti; Vasiraju, Venkata; Lu, Jun; Mashayek, Farzad; Klie, Robert; Vaddiraju, Sreeram; Schwingenschlögl, Udo; Shahbazian-Yassar, Reza

    2015-12-17

    The progress on sodium-ion battery technology faces many grand challenges, one of which is the considerably lower rate of sodium insertion/deinsertion in electrode materials due to the larger size of sodium (Na) ions and complicated redox reactions compared to the lithium-ion systems. Here, it is demonstrated that sodium ions can be reversibly stored in Zn-Sb intermetallic nanowires at speeds that can exceed 295 nm s-1. Remarkably, these values are one to three orders of magnitude higher than the sodiation rate of other nanowires electrochemically tested with in situ transmission electron micro­scopy. It is found that the nanowires display about 161% volume expansion after the first sodiation and then cycle with an 83% reversible volume expansion. Despite their massive expansion, the nanowires can be cycled without any cracking or facture during the ultrafast sodiation/desodiation process. Additionally, most of the phases involved in the sodiation/desodiation process possess high electrical conductivity. More specifically, the NaZnSb exhibits a layered structure, which provides channels for fast Na+ diffusion. This observation indicates that Zn-Sb intermetallic nanomaterials offer great promise as high rate and good cycling stability anodic materials for the next generation of sodium-ion batteries.

  12. Antimony quantification in Leishmania by electrothermal atomic absorption spectroscopy.

    PubMed

    Roberts, W L; Rainey, P M

    1993-05-15

    Tri- and pentavalent antimony were quantified in Leishmania mexicana pifanoi amastigotes and promastigotes by atomic absorption spectroscopy with electrothermal atomization. Leishmania grown in axenic culture were treated with either potassium antimony tartrate [Sb(III)] or sodium stibogluconate [Sb(V)]. The parasites were collected, digested with nitric acid, and subjected to atomic absorption spectroscopy. The method was linear from 0 to 7 ng of antimony. The interassay coefficients of variation were 9.6 and 5.7% (N = 5) for 0.52 and 3.7-ng samples of leishmanial antimony, respectively. The limit of detection was 95 pg of antimony. The assay was used to characterize Sb(III) and Sb(V) influx and efflux kinetics. Influx rates were determined at antimony concentrations that produced a 50% inhibition of growth (IC50). The influx rates of Sb(V) into amastigotes and promastigotes were 4.8 and 12 pg/million cells/h, respectively, at 200 micrograms antimony/ml. The influx rate of Sb(III) into amastigotes was 41 pg/million cells/h at 20 micrograms antimony/ml. Influx of Sb(III) into promastigotes at 1 microgram antimony/ml was rapid and reached a plateau of 175 pg/million cells in 2 h. Efflux of Sb(III) and Sb(V) from amastigotes and promastigotes exhibited biphasic kinetics. The initial (alpha) half-life of Sb(V) efflux was less than 4 min and that of Sb(III) was 1-2 h. The apparent terminal (beta) half-lives ranged from 7 to 14 h.

  13. Antimony Toxicity

    PubMed Central

    Sundar, Shyam; Chakravarty, Jaya

    2010-01-01

    Antimony toxicity occurs either due to occupational exposure or during therapy. Occupational exposure may cause respiratory irritation, pneumoconiosis, antimony spots on the skin and gastrointestinal symptoms. In addition antimony trioxide is possibly carcinogenic to humans. Improvements in working conditions have remarkably decreased the incidence of antimony toxicity in the workplace. As a therapeutic, antimony has been mostly used for the treatment of leishmaniasis and schistosomiasis. The major toxic side-effects of antimonials as a result of therapy are cardiotoxicity (~9% of patients) and pancreatitis, which is seen commonly in HIV and visceral leishmaniasis co-infections. Quality control of each batch of drugs produced and regular monitoring for toxicity is required when antimonials are used therapeutically. PMID:21318007

  14. Antimony Nanocrystals Encapsulated in Carbon Microspheres Synthesized by a Facile Self-Catalyzing Solvothermal Method for High-Performance Sodium-Ion Battery Anodes.

    PubMed

    Qiu, Shen; Wu, Xianyong; Xiao, Lifen; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2016-01-20

    Antimony/carbon (Sb@C) microspheres are initially synthesized via a facile self-catalyzing solvothermal method, and their applicability as anode materials for sodium-ion batteries is investigated. The structural and morphological characterizations reveal that Sb@C microspheres are composed of Sb nanoparticles (∼20 nm) homogeneously encapsulated in the C matrix. The self-catalyzing solvothermal mechanism is verified through comparative experiments by using different raw materials. The as-prepared Sb@C microspheres exhibit superior sodium storage properties, demonstrating a reversible capacity of 640 mAh g(-1), excellent rate performance, and an extended cycling stability of 92.3% capacity retention over 300 cycles, making them promising anode materials for sodium-ion batteries.

  15. Modelling sodium inhibition on the anaerobic digestion process.

    PubMed

    Hierholtzer, A; Akunna, J C

    2012-01-01

    Sodium is a known process inhibitor in anaerobic systems and impacts on methanogens through an increase of osmotic pressure or complete dehydration of microorganisms. In this study, a combination of experimental and modelling approaches has been employed to determine and simulate sodium inhibition on the anaerobic digestion process. The ADM1, which has been successfully used in modelling anaerobic processes, has been modified to include an extra inhibition function that considers the effect of sodium on acetoclastic methanogens and the impact on biogas production and composition. A non-competitive inhibition function was added to the rate of acetate uptake for the model to take into account sodium toxicity. Experimental studies consisted of both batch and reactor tests to obtain parameters for model calibration and validation. The calibrated model was used to predict the effect of ammonia nitrogen on sodium toxicity. It was found that relatively low sodium levels can bring about significant levels of process inhibition in the presence of high levels of ammonia. On the other hand, where the concentration of ammonia is relatively low, the tolerance threshold for sodium ions increases. Hence, care must be taken in the use of sodium hydroxide for pH adjustment during anaerobic digestion of protein-rich substrates.

  16. INHIBITION OF VIRULENCE FACTORS OF PSEUDOMONAS AERUGINOSA BY DICLOFENAC SODIUM.

    PubMed

    Abbas, Hisham A

    2015-01-01

    Resistance of Pseudomonas aeruginosa to antibiotics is a major problem. Targeting virulence factors is an alternative option to avoid the emergence of resistance to antibiotics. The effect of sub-inhibitory concentration of diclofenac sodium on the production of virulence factors of P. aeruginosa was investigated. The virulence factors included protease, haemolysin, pyocyanin and pyoverdin, in addition to pathogenic behaviors such as swimming and twitching motilities and biofilm formation. Diclofenac sodium showed significant inhibition of virulence factors as compared to the control. Diclofenac sodium decreased twitching and swimming motilities by 29.27% and 45.36%, respectively. The percentage of inhibition of pyocyanin by diclofenac sodium was 42.32%. On the other hand, pyoverdin was inhibited to a lesser extent (36.72%). Diclofenac sodium reduced protease by 52.58% and biofilm formation by 58.37%. Moreover, haemolytic activity in the presence of diclofenac sodium was 15.64% as compared to the control (100% haemolytic activity). The inhibitory activities may be due to inhibition of quorum sensing that regulates the expression of virulence factors. This study suggests the potential for the use of diclofenac sodium as an anti-virulence agent in the treatment of Pseudomonas aeruginosa infections.

  17. Inhibition of neutrophil and eosinophil induced chemotaxis by nedocromil sodium and sodium cromoglycate.

    PubMed Central

    Bruijnzeel, P. L.; Warringa, R. A.; Kok, P. T.; Kreukniet, J.

    1990-01-01

    1. Neutrophils and eosinophils infiltrate the airways in association with the allergen-induced late phase asthmatic reaction. Mobilization of these cells takes place via lipid-like and protein-like chemotactic factors. In this study platelet-activating factor (PAF), leukotriene B4 (LTB4), zymosan-activated serum (ZAS) and N-formyl-methionyl-leucyl-phenylalanine (FMLP) were used as illustrative examples of both groups. Chemotaxis was studied in human neutrophils and eosinophils. The inhibitory effects of nedocromil sodium and sodium cromoglycate were evaluated. 2. All chemotactic factors tested attracted neutrophils with the following rank order of activity: ZAS greater than PAF identical to FMLP identical to LTB4. Eosinophils were only mobilized by PAF, LTB4 and ZAS with the following rank order of activity: ZAS greater than PAF greater than LTB4. 3. Nedocromil sodium and sodium cromoglycate were equally active as the PAF antagonist BN 52021 in inhibiting the PAF-induced chemotaxis of neutrophils (IC50 approximately 10(-8) M). Both drugs were also equally active in inhibiting the chemotaxis of neutrophils induced by ZAS (IC50 approximately 10(-7)-10(-6) M), FMLP (IC50 approximately 10(-7) M) and LTB4 (IC50 approximately 10(-6) M). 4. Nedocromil sodium significantly inhibited the chemotaxis of eosinophils induced by PAF (IC50 approximately 10(-6) M) and LTB4 (IC50 approximately 10(-7) M). The inhibitory potency of BN 52021 was similar to that of nedocromil sodium on the PAF-induced chemotaxis of eosinophils. Sodium cromoglycate was incapable of eliciting significant inhibition of these chemotactic responses. However, sodium cromoglycate significantly inhibited the chemotaxis of eosinophils induced by ZAS (IC50 approximately 10(-7) M), whereas nedocromil sodium was ineffective. PMID:2163279

  18. Antimony trioxide

    Integrated Risk Information System (IRIS)

    Antimony trioxide ; CASRN 1309 - 64 - 4 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  19. Bacteria and acid drainage from coal refuse: inhibition by sodium lauryl sulphate and sodium benzoate

    SciTech Connect

    Dugan, P.R.; Apel, W.A.

    1983-01-01

    Studies have shown that the application of an aqueous solution of sodium lauryl sulphate and sodium benzoate to the surface of high-sulphur coal refuse inhibits the activity of iron- and sulphur-oxidising chemo-autotrophic bacteria and reduces the amount of acid drainage from the refuse. Further studies are recommended to assess the usefulness of this method for controlling formation of acid mine drainage in the field.

  20. Sub-optimal dose of Sodium Antimony Gluconate (SAG)-diperoxovanadate combination clears organ parasites from BALB/c mice infected with antimony resistant Leishmania donovani by expanding antileishmanial T-cell repertoire and increasing IFN-gamma to IL-10 ratio.

    PubMed

    Haldar, Arun Kumar; Banerjee, Subha; Naskar, Kshudiram; Kalita, Diganta; Islam, Nashreen S; Roy, Syamal

    2009-06-01

    We demonstrate that the combination of sub-optimal doses of Sodium Antimony Gluconate (SAG) and the diperoxovanadate compound K[VO(O2)2(H2O)], also designated as PV6, is highly effective in combating experimental infection of BALB/c mice with antimony resistant (Sb(R)) Leishmania donovani (LD) as evident from the significant reduction in organ parasite burden where SAG is essentially ineffective. Interestingly, such treatment also allowed clonal expansion of antileishmanial T-cells coupled with robust surge of IFN-c and concomitant decrease in IL-10 production. The splenocytes from the treated animals generated significantly higher amounts of IFN-c inducible parasiticidal effector molecules like superoxide and nitric oxide as compared to the infected group. Our study indicates that the combination of sub-optimal doses of SAG and PV6 may be beneficial for the treatment of SAG resistant visceral leishmaniasis patients.

  1. Inhibition of mitotic-specific histone phophorylation by sodium arsenite

    SciTech Connect

    Cobo, J.M.; Valdez, J.G.; Gurley, L.R.

    1994-10-01

    Synchronized cultures of Chinese hamster cells (line CHO) were used to measure the effects of 10{mu}M sodium arsenite on histone phosphorylation. This treatment caused cell proliferation to be temporarily arrested, after which the cells spontaneously resumed cell proliferation in a radiomimetric manner. Immediately following treatment, it was found that sodium arsenite affected only mitotic-specific HI and H3 phosphorylations. Neither interphase, nor mitotic, H2A and H4 phosphorylations were affected, nor was interphase HI Phosphorylation affected. The phosphorylation of HI was inhibited only in mitosis, reducing HI phosphorylation to 38.1% of control levels, which was the level of interphase HI phosphorylation. The phosphorylation of both H3 variants was inhibited in mitosis, the less hydrophobic H3 to 19% and the more hydrophobic H3 to 24% of control levels. These results suggest that sodium arsenite may inhibite cell proliferation by interfering with the cyclin B/p34{sup cdc2} histone kinase activity which is thought to play a key role in regulating the cell cycle. It has been proposed by our laboratory that HI and H3 phosphorylations play a role in restructuring interphase chromatin into metaphase chromosomes. Interference of this process by sodium arsenite may lead to structurally damaged chromosomes resulting in the increased cancer risks known to be produced by arsenic exposure from the environment.

  2. Preparation, crystal structures and rapid hydration of P2- and P3-type sodium chromium antimony oxides

    SciTech Connect

    Pospelov, A.A.; Nalbandyan, V.B.

    2011-05-15

    Two new Na{sub x}[Cr{sub (1+x)/2}Sb{sub (1-x)/2}]O{sub 2} compounds have been prepared by solid-state reactions in argon. Their structures have been determined by the X-ray Rietveld method. Both new phases together with NaCrO{sub 2}-based solid solution comprise brucite-like layers of edge-shared (Cr,Sb)O{sub 6} octahedra but differ by packing mode of the layers and coordination of the interlayer Na{sup +} ions. A P3 phase exists at x{approx}0.5-0.58. It is rhombohedral (R3-bar m), a=2.966, c=16.937 A at x{approx}0.58, with 29% Na{sup +} occupancy of trigonal prisms. A P2 phase exists at x{approx}0.6-0.7. It is hexagonal (P6{sub 3}/mmc), a=2.960, c=11.190 A at x{approx}0.7, with 37% and 33% Na{sup +} occupancy of two non-equivalent trigonal prisms. Both P2 and P3 phases rapidly absorb moisture in air; packing mode is preserved, the a parameter changes slightly but c increases by 24-25%. Very high sodium ion conductivity is predicted for both P2 and P3 anhydrous phases. -- Graphical Abstract: Polyhedral presentation of layered structures of Na{sub x}[Cr{sub (1+x)/2}Sb{sub (1-x)/2}]O{sub 2}. (Cr,Sb)O{sub 6} octahedra are green. Part of the sodium prisms are open to show short distances between sodium sites which cannot be occupied simultaneously. Display Omitted highlights: > Two new layered Na{sub x}[Cr{sub (1+x)/2}Sb{sub (1-x)/2}]O{sub 2} phases, P2 and P3, have been prepared in argon. > Interlayer O-O distances are larger than in Na{sub x}(M,Ti)O{sub 2} analogs (M=Cr,Ni,Li). > As a result, both rapidly hydrate in air with c-axis expansion of 24-25%. > Bottleneck radii are also larger, and this predicts very high Na{sup +}-ion conductivity.

  3. The Membrane Electrowinning Separation of Antimony from a Stibnite Concentrate

    NASA Astrophysics Data System (ADS)

    Yang, Jian-Guang; Yang, Sheng-Hai; Tang, Chao-Bo

    2010-06-01

    The main purpose of this study was to characterize and to extract antimony from a stibnite concentrate through electrowinning. This article reports an account of a study conducted on the optimization of the process parameters for antimony pentachloride circular leaching, purification, and electrowinning of antimony from antimony trichloride solution. The effect of electrowinning parameters, such as antimony and sodium chloride concentration in the catholyte, temperature, current density, polar distance, etc., on the voltage requirement and the current efficiency (CE) of antimony electrodeposition was explored. A maximum CE of more than 97 pct was attained with a catholyte composition of 70-g/L antimony, 25-g/L NaCl, 4.5-mol/L hydrogen ion concentration, with an anolyte composition of 40-g/L antimony trichloride at a temperature of 328 K (55 °C), a 4-cm polar distance, and a cathode current density of 200 A/m2. Under the optimized conditions, the CE was more than 97 pct, and a 99.98 pct antimony plate was obtained on the cathode. The chemical content analysis of the resulting anolyte was indicated to be 97 pct antimony pentachloride and 3 pct antimony trichloride, which could be recycled to leaching tank as the leaching agent.

  4. Sodium Fluoride Inhibits MMP-2 and MMP-9

    PubMed Central

    Kato, M.T.; Bolanho, A.; Zarella, B.L.; Salo, T.; Tjäderhane, L.; Buzalaf, M.A.R.

    2014-01-01

    The importance of fluoride (F) in preventing dental caries by favorably interfering in the demineralization-remineralization processes is well-established, but its ability to inhibit matrix metalloproteinases (MMPs), which could also help to prevent dentin caries, has not been investigated. This study assessed the ability of F to inhibit salivary and purified human gelatinases MMPs-2 and -9. Saliva was collected from 10 healthy individuals. Pooled saliva was centrifuged, and supernatants were incubated for 1 hr at 37°C and subjected to zymography. Sodium fluoride (50-275 ppm F) was added to the incubation buffer. The reversibility of the inhibition of MMPs-2 and -9 by NaF was tested by the addition of NaF (250-5,000 ppm F) to the incubation buffer, after which an additional incubation was performed in the absence of F. F decreased the activities of pro- and active forms of salivary and purified human MMPs in a dose-response manner. Purified gelatinases were completely inhibited by 200 ppm F (IC50 = 100 and 75 ppm F for MMPs-2 and -9, respectively), and salivary MMP-9 by 275 ppm F (IC50 = 200 ppm F). Inhibition was partially reversible at 250-1,500 ppm F, but was irreversible at 5,000 ppm F. This is the first study to describe the ability of NaF to inhibit MMPs completely. PMID:24196489

  5. Hypertonic saline inhibits luminal sodium channels in respiratory epithelium.

    PubMed

    Hebestreit, Alexandra; Kersting, Ulrich; Hebestreit, Helge

    2007-05-01

    Physical exercise with increased ventilation leads to a considerable rise in water loss from the airways. The mechanisms underlying the regulation of transepithelial fluid transport necessary to compensate for these losses are unknown but may include changes in luminal ion channel conductance. The present study was designed to examine the effects of an increase in luminal chloride and sodium concentrations which may locally occur during hyperventilation on luminal ion conductance in the respiratory epithelium of healthy controls and patients diagnosed with cystic fibrosis (CF). Changes in luminal chloride and sodium conductance were inferred by recording nasal potential difference in eight healthy subjects and 10 patients with CF, using superfusing solutions based on isotonic saline (150 mM) on one occasion and solutions based on hypertonic saline (300 mM) on the other. Switching from isotonic to hypertonic saline superfusion decreased potential difference in controls and CF patients significantly. Amiloride induced a decrease of potential difference which was larger with isotonic than with hypertonic saline (controls 9.5 +/- 6.1 vs. 3.7 +/- 4.6 mV; CF 17.2 +/- 7.2 vs. 9.8 +/- 7.6 mV). Chloride conductance stimulated with solutions low in chloride and containing isoproterenol was not significantly changed by hypertonic saline solutions compared with isotonic solutions in both groups. The findings indicate a significant inhibition of luminal sodium conductance by high luminal sodium concentrations. This mechanism may be involved in the regulation of fluid transport across the respiratory epithelium during exercise and in the improvement of mucociliary clearance and lung functions with inhalation of hypertonic saline in CF.

  6. Inhibition of aspirin-induced bronchoconstriction by sodium cromoglycate inhalation.

    PubMed Central

    Martelli, N A; Usandivaras, G

    1977-01-01

    Five patients with asthma and severe aspirin hypersensitivity were challenged on separate days with increasing doses of aspirin given by mouth, starting with 5 mg, until a reduction in FEV1 greater than 15% was obtained. Sodium cromoglycate in doses of 20-40 mg inhibited the bronchoconstrictive reaction not only when inhaled before the challenge but also after it, at a time when progressive reduction in FEV1 values was taking place. According to these results, it seems reasonable to postulate sequential mast cell degranulation and liberation of mediators of anaphylaxis as the mechanism through which aspirin induces bronchoconstriction in aspirin-sensitive asthmatics. The differences between bronchial provocation tests and oral challenge with aspirin are stressed. PMID:414371

  7. On line automated system for the determination of Sb(V), Sb(III), thrimethyl antimony(v) and total antimony in soil employing multisyringe flow injection analysis coupled to HG-AFS.

    PubMed

    Silva Junior, Mario M; Portugal, Lindomar A; Serra, Antonio M; Ferrer, Laura; Cerdà, Victor; Ferreira, Sergio L C

    2017-04-01

    This paper proposes the use of a multisyringe flow injection analysis (MSFIA) system for inorganic antimony speciation analysis, trimethyl antimony(V) and determination of total antimony in soil samples using hydride generation atomic fluorescence spectrometry (HG-AFS). Total antimony has been determined after reduction of antimony(V) to antimony(III) using potassium iodide and ascorbic acid. For determination of total inorganic antimony the sample is percolated in a mini-column containing the Dowex 50W-X8 resin for retention of the organic species of antimony. Antimony(III) is quantified in presence of 8-hydroxyquinoline as masking agent for antimony(V) after an extraction step of the organic antimony species using the also same mini-column. The trimethyl antimony(V) content is found by difference between total antimony and total inorganic antimony. By other hand, antimony(V) is quantified by difference between total inorganic antimony and antimony(III). The analytical determinations were performed using sodium tetrahydroborate as reducing agent. The optimization step was performed using two-level full factorial design and Doehlert matrix involving the factors: hydrochloric acid and sodium tetrahydroborate concentrations and sample flow rate. The optimized experimental conditions allow the antimony determination utilizing the external calibration technique with limits of detection and quantification of 0.9 and 3.1ngg(-1), respectively, and a precision expressed as relative standard deviation of 3.2% for an antimony solution of 5.0µgL(-1). The method accuracy was confirmed by analysis of the soil certified reference material furnished from Sigma-Aldrich RTC. Additionally, addition/recovery tests were performed employing synthetic solutions prepared using trimethyl antimony(V), antimony(III), antimony(V) and five soil samples. The antimony extraction step was performed in a closed system using hydrochloric acid, ultrasonic radiation and controlled temperature. The

  8. Antimony: a flame fighter

    USGS Publications Warehouse

    Wintzer, Niki E.; Guberman, David E.

    2015-01-01

    In the 11th century, the word antimonium was used by medieval scholar Constantinus Africanus, but antimony metal was not isolated until the 16th century by Vannoccio Biringuccio, an Italian metallurgist. In the early 18th century, chemist Jons Jakob Berzelius chose the periodic symbol for antimony (Sb) based on stibium, which is the Latin name for stibnite.

  9. Comparative trials of antimonial drugs in urinary schistosomiasis

    PubMed Central

    Davis, A.

    1968-01-01

    Chemotherapeutic trials in urinary schistosomiasis are described and discussed. Their design and conduct were based on recommended statistical techniques, now generally accepted as the most appropriate approach to the assessment of antischistosomal drugs. Randomization produced comparable host groups in whom multiple parasitic infection and radiological urinary tract damage were common. Treatment was with one of three antimonial compounds given at equivalent metallic dosage daily. Antimony sodium tartrate (AST) and antimony dimercaptosuccinate (TWSb) were equally efficient curatively but both produced many side-effects. Sodium antimonylgluconate (TSAG) was four-fifths as effective but tolerance was superior. Estimations of urinary antimony excretion showed that tissue retention of the metal was related to cure-rates and side-effects. It was concluded that none of the drugs were suitable for mass chemotherapy. More new non-toxic schistosomicides are urgently needed and for their assessment, the setting-up of multicentre trials, following international agreement on technical methods, is suggested. PMID:5302298

  10. Separation of sodium-22 from irradiated targets

    DOEpatents

    Taylor, Wayne A.; Jamriska, David

    1996-01-01

    A process for selective separation of sodium-22 from an irradiated target including dissolving an irradiated target to form a first solution, contacting the first solution with hydrated antimony pentoxide to selectively separate sodium-22 from the first solution, separating the hydrated antimony pentoxide including the separated sodium-22 from the first solution, dissolving the hydrated antimony pentoxide including the separated sodium-22 in a mineral acid to form a second solution, and, separating the antimony from the sodium-22 in the second solution.

  11. Bradykinin-induced bronchoconstriction: inhibition by nedocromil sodium and sodium cromoglycate.

    PubMed Central

    Dixon, C M; Barnes, P J

    1989-01-01

    1. The effects of inhaled nedocromil sodium and sodium cromoglycate on bradykinin-induced bronchoconstriction have been studied in a double-blind, placebo controlled study, in eight mild asthmatic subjects. 2. The subjects attended on four occasions. Fifteen minutes after drug pre-treatment a bradykinin challenge was performed. Increasing concentrations were inhaled until a greater than 40% fall in expiratory flow at 30% of vital capacity from a partial flow volume manoeuvre (V p30) was demonstrated. 3. Inhaled bradykinin (0.06-8.0 mg ml-1) caused dose-related bronchoconstriction with the geometric mean cumulative dose causing a 40% fall in V p30 (PD40) of 0.035 (95% CI: 0.02-0.07) mumol, after placebo inhalation, which was similar to that measured before the trial (0.04: 0.02-0.09 mumol). 4. Both nedocromil sodium (4 mg) and sodium cromoglycate (10 mg) gave significant protection (P less than 0.05) against bradykinin-induced bronchoconstriction (PD40 0.37: 0.19-0.72 mumol after nedocromil sodium and 0.22: 0.11-0.49 after sodium cromoglycate). 5. Since bradykinin-induced bronchoconstriction is probably neurally mediated we conclude that both nedocromil sodium and sodium cromoglycate have an action on neural pathways which may be useful in the control of asthma symptoms. PMID:2547408

  12. [The corrosion behavior of antimony in a Ag-Sn-Cu-Sb amalgam].

    PubMed

    Weiland, M; Borrmann, S; Nossek, H

    1989-01-01

    Specimen of amalgam containing antimony were stored in solutions with different pH and different content of rhodanide until 21 days. The most antimony were solved within 24 hours. After 7 days an increase of the antimony concentration were not observed in physiological pH. An inhibition of corrosion by rhodanide existed only after incubation from 21 days. The quantity of antimony (10-21 micrograms) were analysed by mean of atomic absorption spectroscopy. It represent not a risk for the health. The natural presence of this element in environment and in human body is discussed to the analysed quantity of solved antimony.

  13. Effect of inhibition of converting enzyme on renal hemodynamics and sodium management in polycystic kidney disease.

    PubMed

    Torres, V E; Wilson, D M; Burnett, J C; Johnson, C M; Offord, K P

    1991-10-01

    We compared the tubular transport of sodium and the erythrocyte sodium-lithium countertransport activity in hypertensive patients with autosomal dominant polycystic kidney disease (ADPKD) and in normotensive control subjects. In addition, we assessed the effects of inhibition of converting enzyme on renal hemodynamics and sodium excretion in hypertensive patients with ADPKD to provide information on mechanisms responsible for the increased renal vascular resistance and filtration fraction and the adjustment of the pressure-natriuresis relationship during saline expansion, observed in patients with ADPKD, hypertension, and preserved renal function. In comparison with normotensive control subjects, the hypertensive patients with ADPKD had lower renal plasma flows, higher renal vascular resistances and filtration fractions, and similar proximal and distal fractional reabsorptions of sodium. The administration of enalapril resulted in significant increases in the renal plasma flow and significant reductions in mean arterial pressure, renal vascular resistance, and filtration fraction, but the glomerular filtration rate remained unchanged. Despite the significant reduction in mean arterial pressure during inhibition of converting enzyme, the distal fractional reabsorption of sodium decreased while the total fractional excretion of sodium remained unchanged or increased slightly. No significant differences were detected between the normotensive control subjects and the hypertensive patients with ADPKD in erythrocyte sodium-lithium countertransport activity, plasma renin activity, plasma aldosterone concentration, or atrial natriuretic factor. These results suggest that the renal renin-angiotensin system plays a central role in the alterations in renal hemodynamics and sodium management associated with the development of hypertension in ADPKD.

  14. A mathematical model of long-term renal sympathetic nerve activity inhibition during an increase in sodium intake

    PubMed Central

    Denizhan, Yagmur; Hester, Robert

    2013-01-01

    It is well known that renal nerves directly affect renal vascular resistance, tubular sodium reabsorption, and renin secretion. Inhibition of renal sympathetic nerve activity (RSNA) decreases renal vascular resistance, tubular sodium reabsorption, and renin secretion, leading to an increase in sodium excretion. Although several studies show that inhibition of RSNA promotes sodium excretion during an acute blood volume expansion, there is limited research relating to the importance of RSNA inhibition that contributes to sodium homeostasis during a long-term increase in sodium intake. Therefore, to dissect the underlying mechanisms of sodium excretion, a mathematical model of a cardiovascular system consisting of two kidneys, each with an independent RSNA, was developed. Simulations were performed to determine the responses of RSNA and sodium excretion to an increased sodium intake. In these simulations, RSNA in the left kidney was fixed at its normal steady-state value, while RSNA in the contralateral kidney was allowed to change normally in response to the increased sodium intake. The results demonstrate that the fixed-RSNA kidney excretes less sodium than the intact-RSNA collateral kidney. Because each kidney is exposed to the same arterial pressure and circulatory hormones, the impaired sodium excretion in the absence of RSNA inhibition supports the hypothesis that RSNA inhibition contributes to natriuresis in response to a long-term increase in sodium intake. PMID:24285363

  15. Sodium acetate inhibits Staphylococcus aureus internalization into bovine mammary epithelial cells by inhibiting NF-κB activation.

    PubMed

    Wei, Zhengkai; Xiao, Chong; Guo, Changming; Zhang, Xu; Wang, Yanan; Wang, Jingjing; Yang, Zhengtao; Fu, Yunhe

    2017-03-27

    Bovine mastitis is one of the most costly and prevalent disease affecting dairy cows worldwide. It was reported that Staphylococcus aureus could internalize into bovine mammary epithelial cells (bMEC) and induce mastitis. Some short chain fatty acids (SCFA) have shown to suppress S. aureus invasion into bMEC and regulate antimicrobial peptides expression. But it has not been evaluated that sodium acetate has the similar effect. The aim of this study was to investigate the effect of sodium acetate on the invasion of bovine mammary epithelial cells (bMEC) by S. aureus. Gentamicin protection assay showed that the invasion of S. aureus into bMEC was inhibited by sodium acetate in a dose-dependent manner. Sodium acetate (0.25-5 mM) did not affect S. aureus growth and bMEC viability. The TAP gene level was decreased, while the BNBD5 mRNA level was enhanced in sodium acetate treated bMEC. In sodium acetate treated and S. aureus challenged bMEC, the TAP gene expression was increased and BNBD5 gene expression was not modified at low concentrations, but decreased at high concentrations. The Nitric oxide (NO) production of bMEC after S. aureus stimulation was decreased by sodium acetate treatment. Furthermore, sodium acetate treatment suppressed S. aureus-induced NF-κB activation in bMEC in a dose manner. In conclusion, our results suggested that sodium acetate exerts an inhibitory property on S. aureus internalization and modulates antimicrobial peptides gene expression.

  16. Corticotropin-releasing hormone in the lateral parabrachial nucleus inhibits sodium appetite in rats.

    PubMed

    De Castro e Silva, Emilio; Fregoneze, Josmara B; Johnson, Alan Kim

    2006-04-01

    The present study investigated the role of corticotropin-releasing hormone (CRH) in the lateral parabrachial nucleus (LPBN) in the behavioral control of body fluid homeostasis by determining the effect of bilateral injections of the CRH receptor antagonist, alpha-helical corticotropin-releasing factor (CRF)(9-41), and the CRH receptor agonist, CRH, on sodium chloride (salt appetite) and water (thirst) intake. Groups of adult, male Sprague-Dawley rats had stainless-steel cannulas implanted bilaterally into the LPBN and were sodium depleted or water deprived. Bilateral injections of alpha-helical CRF(9-41) into the LPBN significantly potentiated water and salt intake in the sodium-depleted rats when access to fluids was restored. Bilateral injections of alpha-helical CRF(9-41) into the LPBN (1.0 microg) also increased sodium appetite in water-deprived rats. Conversely, in sodium-depleted animals, bilateral injections of CRH inhibited sodium chloride intake. These results suggest that there is an endogenous CRH inhibitory mechanism operating in the LPBN to modulate the intake of sodium (salt appetite). This mechanism may contribute to the behavioral control of restoration of body fluid homeostasis in sodium-deficient states.

  17. Dopamine and angiotensin type 2 receptors cooperatively inhibit sodium transport in human renal proximal tubule cells.

    PubMed

    Gildea, John J; Wang, Xiaoli; Shah, Neema; Tran, Hanh; Spinosa, Michael; Van Sciver, Robert; Sasaki, Midori; Yatabe, Junichi; Carey, Robert M; Jose, Pedro A; Felder, Robin A

    2012-08-01

    Little is known regarding how the kidney shifts from a sodium and water reclaiming state (antinatriuresis) to a state where sodium and water are eliminated (natriuresis). In human renal proximal tubule cells, sodium reabsorption is decreased by the dopamine D(1)-like receptors (D(1)R/D(5)R) and the angiotensin type 2 receptor (AT(2)R), whereas the angiotensin type 1 receptor increases sodium reabsorption. Aberrant control of these opposing systems is thought to lead to sodium retention and, subsequently, hypertension. We show that D(1)R/D(5)R stimulation increased plasma membrane AT(2)R 4-fold via a D(1)R-mediated, cAMP-coupled, and protein phosphatase 2A-dependent specific signaling pathway. D(1)R/D(5)R stimulation also reduced the ability of angiotensin II to stimulate phospho-extracellular signal-regulated kinase, an effect that was partially reversed by an AT(2)R antagonist. Fenoldopam did not increase AT(2)R recruitment in renal proximal tubule cells with D(1)Rs uncoupled from adenylyl cyclase, suggesting a role of cAMP in mediating these events. D(1)Rs and AT(2)Rs heterodimerized and cooperatively increased cAMP and cGMP production, protein phosphatase 2A activation, sodium-potassium-ATPase internalization, and sodium transport inhibition. These studies shed new light on the regulation of renal sodium transport by the dopaminergic and angiotensin systems and potential new therapeutic targets for selectively treating hypertension.

  18. Mode of Action of the Natural Insecticide, Decaleside Involves Sodium Pump Inhibition

    PubMed Central

    Rajashekar, Yallappa; Shivanandappa, Thimmappa

    2017-01-01

    Decalesides are a new class of natural insecticides which are toxic to insects by contact via the tarsal gustatory chemosensilla. The symptoms of their toxicity to insects and the rapid knockdown effect suggest neurotoxic action, but the precise mode of action and the molecular targets for decaleside action are not known. We have presented experimental evidence for the involvement of sodium pump inhibition in the insecticidal action of decaleside in the cockroach and housefly. The knockdown effect of decaleside is concomitant with the in vivo inhibition of Na+, K+ -ATPase in the head and thorax. The lack of insecticidal action by experimental ablation of tarsi or blocking the tarsal sites with paraffin correlated with lack of inhibition of Na+- K+ ATPase in vivo. Maltotriose, a trisaccharide, partially rescued the toxic action of decaleside as well as inhibition of the enzyme, suggesting the possible involvement of gustatory sugar receptors. In vitro studies with crude insect enzyme preparation and purified porcine Na+, K+ -ATPase showed that decaleside competitively inhibited the enzyme involving the ATP binding site. Our study shows that the insecticidal action of decaleside via the tarsal gustatory sites is causally linked to the inhibition of sodium pump which represents a unique mode of action. The precise target(s) for decaleside in the tarsal chemosensilla and the pathway linked to inhibition of sodium pump and the insecticidal action remain to be understood. PMID:28125742

  19. Sodium alginate inhibits methotrexate-induced gastrointestinal mucositis in rats.

    PubMed

    Yamamoto, Atsuki; Itoh, Tomokazu; Nasu, Reishi; Kajiwara, Eiji; Nishida, Ryuichi

    2013-01-01

    Gastrointestinal mucositis is one of the most prevalent side effects of chemotherapy. Methotrexate is a pro-oxidant compound that depletes dihydrofolate pools and is widely used in the treatment of leukemia and other malignancies. Through its effects on normal tissues with high rates of proliferation, methotrexate treatment leads to gastrointestinal mucositis. In rats, methotrexate-induced gastrointestinal mucositis is histologically characterized by crypt loss, callus fusion and atrophy, capillary dilatation, and infiltration of mixed inflammatory cells. The water-soluble dietary fiber sodium alginate (AL-Na) is derived from seaweed and has demonstrated muco-protective and hemostatic effects on upper gastrointestinal ulcers. In the present study, we evaluated the effects of AL-Na on methotrexate-induced small intestinal mucositis in rats. Animals were subcutaneously administered methotrexate at a dosage of 2.5 mg/kg once daily for 3 d. Rats were treated with single oral doses of AL-Na 30 min before and 6 h after methotrexate administration. On the 4th day, small intestines were removed and weighed. Subsequently, tissues were stained with hematoxylin-eosin and bromodeoxyuridine. AL-Na significantly prevented methotrexate-induced small intestinal mucositis. Moreover, AL-Na prevented decreases in red blood cell numbers, hemoglobin levels, and hematocrit levels. These results suggest the potential of AL-Na as a therapy for methotrexate-induced small intestinal mucositis.

  20. Elucidation of the mechanism of enzymatic browning inhibition by sodium chlorite

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sodium chlorite (SC) is a well known anti-microbial agent and its strong inhibitory effect on enzymatic browning of fresh-cut produce has recently been identified. We investigated the mechanisms of browning inhibition by SC using chlorogenic acid (CA) and PPO extracted from mushroom to emulate the b...

  1. Inhibition of platelet-activating factor- and zymosan-activated serum-induced chemotaxis of human neutrophils by nedocromil sodium, BN 52021 and sodium cromoglycate.

    PubMed Central

    Bruijnzeel, P. L.; Warringa, R. A.; Kok, P. T.

    1989-01-01

    1. Inflammatory cells such as eosinophils and neutrophils are thought to contribute actively to the pathogenesis of asthma since they infiltrate into the lung tissue. These cells are mobilized by lipid-like and protein-like chemotactic factors. As illustrative examples of both groups, platelet-activating-factor (Paf) and zymosan-activated-serum (ZAS) were used in this study. The inhibitory effects of nedocromil sodium, the Paf antagonist BN 52021 and sodium cromoglycate on Paf- and ZAS-induced neutrophil chemotaxis were evaluated. 2. All tested drugs inhibited Paf-induced neutrophil chemotaxis with approximately the same potency (IC50 approximately 1 nM). 3. Nedocromil sodium and sodium cromoglycate were equally potent in inhibiting ZAS-induced neutrophil chemotaxis (IC50 = 0.1-1 microM), whereas BN 52021 was considerably less potent (IC30 = 10 microM). 4. To find out whether the drugs tested could inhibit early events in cell activation, their capacity to inhibit Paf- and ZAS-induced cytosolic free Ca2+-mobilization was investigated. BN 52021, at a concentration of 100 microM, completely inhibited Paf-induced Ca2+-mobilization and inhibited ZAS-induced Ca2+-mobilization by about 50%. Nedocromil sodium and sodium cromoglycate were ineffective. PMID:2551444

  2. Sodium-glucose cotransporter 2 inhibition and health benefits: The Robin Hood effect

    PubMed Central

    Kalra, Sanjay; Jain, Arpit; Ved, Jignesh; Unnikrishnan, A. G.

    2016-01-01

    This review discusses two distinct, yet related, mechanisms of sodium-glucose cotransporter 2 (SGLT2) inhibition: Calorie restriction mimicry (CRM) and pro-ketogenic effect, which may explain their cardiovascular benefits. We term these adaptive CRM and pro-ketogenic effects of SGLT2 inhibition, the Robin Hood hypothesis. In English history, Robin Hood was a “good person,” who stole from the rich and helped the poor. He supported redistribution of resources as he deemed fit for the common good. In a similar fashion, SGLT2 inhibition provides respite to the overloaded glucose metabolism while utilizing lipid stores for energy production. PMID:27730088

  3. Sodium-glucose cotransporter 2 inhibition and health benefits: The Robin Hood effect.

    PubMed

    Kalra, Sanjay; Jain, Arpit; Ved, Jignesh; Unnikrishnan, A G

    2016-01-01

    This review discusses two distinct, yet related, mechanisms of sodium-glucose cotransporter 2 (SGLT2) inhibition: Calorie restriction mimicry (CRM) and pro-ketogenic effect, which may explain their cardiovascular benefits. We term these adaptive CRM and pro-ketogenic effects of SGLT2 inhibition, the Robin Hood hypothesis. In English history, Robin Hood was a "good person," who stole from the rich and helped the poor. He supported redistribution of resources as he deemed fit for the common good. In a similar fashion, SGLT2 inhibition provides respite to the overloaded glucose metabolism while utilizing lipid stores for energy production.

  4. The abnormal in vitro response to aspirin of platelets from aspirin-sensitive asthmatics is inhibited after inhalation of nedocromil sodium but not of sodium cromoglycate.

    PubMed Central

    Marquette, C H; Joseph, M; Tonnel, A B; Vorng, H; Lassalle, P; Tsicopoulos, A; Capron, A

    1990-01-01

    1. Blood platelets from patients with aspirin-sensitive asthma (ASA) generated cytotoxic mediators in the presence of aspirin. This abnormal in vitro response to aspirin was abolished within 1 h after nedocromil sodium inhalation but not after sodium cromoglycate inhalation. 2. Platelets recovered this reactivity to aspirin by 12 hours after nedocromil sodium treatment of ASA-patients. 3. The in vitro reactivity to aspirin of ASA platelets isolated before inhalation was inhibited in the presence of serum isolated 15 and 60 min after nedocromil sodium inhalation. PMID:2161678

  5. Epitaxial Silicon Doped With Antimony

    NASA Technical Reports Server (NTRS)

    Huffman, James E.; Halleck, Bradley L.

    1996-01-01

    High-purity epitaxial silicon doped with antimony made by chemical vapor deposition, using antimony pentachloride (SbCI5) as source of dopant and SiH4, SiCI2H2, or another conventional source of silicon. High purity achieved in layers of arbitrary thickness. Epitaxial silicon doped with antimony needed to fabricate impurity-band-conduction photodetectors operating at wavelengths from 2.5 to 40 micrometers.

  6. Inhibition of mouse B16 melanoma by sodium butyrate correlated to tumor associated macrophages differentiation suppression

    PubMed Central

    Xiong, Fen; Mou, Yun-Zhu; Xiang, Xiao-Yan

    2015-01-01

    Objective: As one member of the histone deacetylase inhibitor (HDACi) family, Sodium butyrate (NaB) was found out that could be used as a differentiation inducer of much cancer cell. But its effects on tumor microenvironment cells are not well recognized. The goal of this research is to investigate the effect of NaB on B16 melanoma and analysis its relevant mechanism. Methods: We observed the effect of sodium butyrate on B16 melanoma in vivo and in vitro. MTT method was performed to detect cell apoptosis rate after treatment. Tumor associated macrophage infiltration condition was detected by flow cytometry. Western-blotting and immunohistochemical method were used to detect the expression of tumor associated macrophage cytokines. Results: A certain concentration of sodium butyrate could effectively inhibit B16 melanoma growth in vivo and in vitro, and this inhibition effects related to the suppression of tumor associated macrophage differentiation. At the same time we observed the relevant macrophage factors were down-regulated compared to the control. Conclusion: Sodium butyrate could effectively inhibit B16 melanoma growth through suppressing tumor associated macrophage proliferation and reduce relevant pro-tumor macrophage factors expression, which may help to promote the clinical study of melanoma epigenetic therapy. PMID:26064327

  7. Tetrodotoxin-sensitive α-subunits of voltage-gated sodium channels are relevant for inhibition of cardiac sodium currents by local anesthetics.

    PubMed

    Stoetzer, C; Doll, T; Stueber, T; Herzog, C; Echtermeyer, F; Greulich, F; Rudat, C; Kispert, A; Wegner, F; Leffler, A

    2016-06-01

    The sodium channel α-subunit (Nav) Nav1.5 is regarded as the most prevalent cardiac sodium channel required for generation of action potentials in cardiomyocytes. Accordingly, Nav1.5 seems to be the main target molecule for local anesthetic (LA)-induced cardiotoxicity. However, recent reports demonstrated functional expression of several "neuronal" Nav's in cardiomyocytes being involved in cardiac contractility and rhythmogenesis. In this study, we examined the relevance of neuronal tetrodotoxin (TTX)-sensitive Nav's for inhibition of cardiac sodium channels by the cardiotoxic LAs ropivacaine and bupivacaine. Effects of LAs on recombinant Nav1.2, 1.3, 1.4, and 1.5 expressed in human embryonic kidney cell line 293 (HEK-293) cells, and on sodium currents in murine, cardiomyocytes were investigated by whole-cell patch clamp recordings. Expression analyses were performed by reverse transcription PCR (RT-PCR). Cultured cardiomyocytes from neonatal mice express messenger RNA (mRNA) for Nav1.2, 1.3, 1.5, 1.8, and 1.9 and generate TTX-sensitive sodium currents. Tonic and use-dependent block of sodium currents in cardiomyocytes by ropivacaine and bupivacaine were enhanced by 200 nM TTX. Inhibition of recombinant Nav1.5 channels was similar to that of TTX-resistant currents in cardiomyocytes but stronger as compared to inhibition of total sodium current in cardiomyocytes. Recombinant Nav1.2, 1.3, 1.4, and 1.5 channels displayed significant differences in regard to use-dependent block by ropivacaine. Finally, bupivacaine blocked sodium currents in cardiomyocytes as well as recombinant Nav1.5 currents significantly stronger in comparison to ropivacaine. Our data demonstrate for the first time that cardiac TTX-sensitive sodium channels are relevant for inhibition of cardiac sodium currents by LAs.

  8. Reductive precipitation of metals photosensitized by tin and antimony porphyrins

    DOEpatents

    Shelnutt, John A.; Gong, Weiliang; Abdelouas, Abdesselam; Lutze, Werner

    2003-09-30

    A method for reducing metals using a tin or antimony porphyrin by forming an aqueous solution of a tin or antimony porphyrin, an electron donor, such as ethylenediaminetetraaceticacid, triethylamine, triethanolamine, and sodium nitrite, and at least one metal compound selected from a uranium-containing compound, a mercury-containing compound, a copper-containing compound, a lead-containing compound, a gold-containing compound, a silver-containing compound, and a platinum-containing compound through irradiating the aqueous solution with light.

  9. Immobilization of antimony waste slag by applying geopolymerization and stabilization/solidification technologies.

    PubMed

    Salihoglu, Güray

    2014-11-01

    During the processing of antimony ore by pyrometallurgical methods, a considerable amount of slag is formed. This antimony waste slag is listed by the European Union as absolutely hazardous waste with a European Waste Catalogue code of 10 08 08. Since the levels of antimony and arsenic in the leachate of the antimony waste slag are generally higher than the landfilling limits, it is necessary to treat the slag before landfilling. In this study, stabilization/solidification and geopolymerization technologies were both applied in order to limit the leaching potential of antimony and arsenic. Different combinations ofpastes by using Portland cement, fly ash, clay, gypsum, and blast furnace slag were prepared as stabilization/solidification or geopoljymer matrixes. Sodium silicate-sodium hydroxide solution and sodium hydroxide solution at 8 M were used as activators for geopolymer samples. Efficiencies of the combinations were evaluated in terms of leaching and unconfined compressive strength. None of the geopolymer samples prepared with the activators yielded arsenic and antimony leaching below the regulatory limit at the same time, although they yielded high unconfined compressive strength levels. On the other hand, the stabilization/solidification samples prepared by using water showed low leaching results meeting the landfilling criteria. Use of gypsum as an additive was found to be successful in immobilizing the arsenic and antimony.

  10. Inhibition of Salmonella Enteritidis by cerein 8A, EDTA and sodium lactate.

    PubMed

    Lappe, Rosiele; Motta, Amanda S; Sant'anna, Voltaire; Brandelli, Adriano

    2009-11-15

    The ability of the bacteriocin cerein 8A to inhibit Salmonella Enteritidis in combination with EDTA and sodium lactate was investigated. Salmonella Enteritidis was incubated with combinations of cerein 8A (3200AU/mL) and EDTA (20, 50, 100 mmol/L) or sodium lactate (200 mmol/L). All treatments caused a significant reduction in the OD(600) values of Salmonella Enteritidis cultures. The addition of cerein 8A plus EDTA resulted in higher inhibition in comparison with the bacteriocin alone; the greater the concentration of EDTA, the greater the inhibitory effect. The combination of cerein 8A plus 100 mmol/L EDTA results in a more efficient treatment to reduce the number of viable cells of Salmonella Enteritidis. The combination of cerein 8A plus sodium lactate also showed significant inhibition of the indicator organism. Transmission electron microscopy showed damaged cell walls and loss of protoplasmic material in treated cells. The cells of Salmonella Enteritidis treated with cerein 8A plus EDTA appeared more injured. The bacteriocin cerein 8A may be useful to inhibit Gram-negative bacteria, with enhanced effect in combination with chelating agents. Control of Salmonella Enteritidis, a Gram-negative bacterium constantly linked to food outbreaks, addresses an important aspect of food safety.

  11. Sodium-glucose cotransporter-2 inhibition and the insulin: Glucagon ratio: Unexplored dimensions

    PubMed Central

    Kalra, Sanjay; Gupta, Yashdeep; Patil, Shiva

    2015-01-01

    The sodium-glucose cotransporter 2 (SGLT-2) inhibitors are a novel class of glucose-lowering drugs which act by inhibiting the reabsorption of filtered glucose from the kidneys. Their effect on insulin and glucagon levels has recently been studied but is not fully explained. This communication proposes various hypotheses: A direct effect of SGLT-2 inhibition on the alpha cell receptors, a paracrine or intra-islet mediated effect on alpha cell sensitivity to glucose, and a calorie restriction mimetic action, to explain the impact of these drugs on the insulin glucagon ratio. PMID:25932403

  12. Oligosilanylated Antimony Compounds

    PubMed Central

    2015-01-01

    By reactions of magnesium oligosilanides with SbCl3, a number of oligosilanylated antimony compounds were obtained. When oligosilanyl dianions were used, either the expected cyclic disilylated halostibine was obtained or alternatively the formation of a distibine was observed. Deliberate formation of the distibine from the disilylated halostibine was achieved by reductive coupling with C8K. Computational studies of Sb–Sb bond energies, barriers of pyramidal inversion at Sb, and the conformational behavior of distibines provided insight for the understanding of the spectroscopic properties. PMID:25937691

  13. F 15845 inhibits persistent sodium current in the heart and prevents angina in animal models

    PubMed Central

    Vacher, B; Pignier, C; Létienne, R; Verscheure, Y; Le Grand, B

    2009-01-01

    Background and purpose: Activation of the persistent sodium current in ischaemic myocardium results in calcium overload which is toxic for the cardiomyocyte. Thus, the activity of 3-(R)-[3-(2-methoxyphenylthio-2-(S)-methylpropyl]amino-3,4-dihydro-2H-1,5 benzoxathiepine bromhydrate (F 15845), a new selective persistent sodium current blocker, in protecting against the effects of cardiac ischaemia was examined, in both in vitro and in vivo models. Experimental approach: Electrophysiological studies using patch-clamp and conventional microlelectrode techniques, isolated perfused hearts and models of angina in anaesthetized animals were used to assess the protection afforded by F 15845 against ischaemia-induced changes. Key results: F 15845 reduced the persistent sodium current activated by veratridine (IC50 1.58 × 10−6 mol·L−1). F 15845 blocked voltage-gated human cardiac sodium channels in a novel, voltage-dependent manner, selectively affecting steady-state inactivation. F 15845 did not affect action potential shape and basal function of guinea pig isolated perfused hearts but did reduce ischaemia-induced diastolic contracture in this model (IC50 0.64 × 10−6 mol·L−1). In rabbits, F 15845 given i.v. (ED50 0.05 mg·kg−1) or orally (ED50 0.13 mg·kg−1) dose-dependently and powerfully inhibited regional myocardial ischaemia-induced ST segment elevation in the absence of haemodynamic effects, implying direct cardiac activity. In dogs, F 15845 dose-dependently inhibited epicardial ST segment changes (70 ± 8% at 0.63 mg·kg−1) in an experimental angina model of demand ischaemia, again without haemodynamic effects, confirming a direct anti-anginal activity. Conclusions and implications: F 15845 is a selective, potent blocker of the persistent sodium current, generated by the human Nav1.5 channel isoforms, and prevents cardiac angina in animal models. PMID:19133985

  14. Cobalt and antimony: genotoxicity and carcinogenicity.

    PubMed

    De Boeck, Marlies; Kirsch-Volders, Micheline; Lison, Dominique

    2003-12-10

    The purpose of this review is to summarise the data concerning genotoxicity and carcinogenicity of Co and Sb. Both metals have multiple industrial and/or therapeutical applications, depending on the considered species. Cobalt is used for the production of alloys and hard metal (cemented carbide), diamond polishing, drying agents, pigments and catalysts. Occupational exposure to cobalt may result in adverse health effects in different organs or tissues. Antimony trioxide is primarily used as a flame retardant in rubber, plastics, pigments, adhesives, textiles, and paper. Antimony potassium tartrate has been used worldwide as an anti-shistosomal drug. Pentavalent antimony compounds have been used for the treatment of leishmaniasis. Co(II) ions are genotoxic in vitro and in vivo, and carcinogenic in rodents. Co metal is genotoxic in vitro. Hard metal dust, of which occupational exposure is linked to an increased lung cancer risk, is proven to be genotoxic in vitro and in vivo. Possibly, production of active oxygen species and/or DNA repair inhibition are mechanisms involved. Given the recently provided proof for in vitro and in vivo genotoxic potential of hard metal dust, the mechanistic evidence of elevated production of active oxygen species and the epidemiological data on increased cancer risk, it may be advisable to consider the possibility of a new evaluation by IARC. Both trivalent and pentavalent antimony compounds are generally negative in non-mammalian genotoxicity tests, while mammalian test systems usually give positive results for Sb(III) and negative results for Sb(V) compounds. Assessment of the in vivo potential of Sb2O3 to induce chromosome aberrations (CA) gave conflicting results. Animal carcinogenicity data were concluded sufficient for Sb2O3 by IARC. Human carcinogenicity data is difficult to evaluate given the frequent co-exposure to arsenic. Possible mechanisms of action, including potential to produce active oxygen species and to interfere with

  15. Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation

    SciTech Connect

    Tostar, Sandra; Stenvall, Erik; Boldizar, Antal; Foreman, Mark R. St. J.

    2013-06-15

    Highlights: • We have proposed a method to recover antimony from electronic plastics. • The most efficient acid solution was sodium hydrogen tartrate in dimethyl sulfoxide. • Gamma irradiation did not influence the antimony leaching ability. - Abstract: There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5 M) dissolved in either dimethyl sulfoxide or water (at ca. 23 °C and heated to ca. 105 °C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed.

  16. Effect of antimony on the microbial growth and the activities of soil enzymes.

    PubMed

    An, Youn-Joo; Kim, Minjin

    2009-02-01

    The effects of antimony (Sb) on microbial growth inhibition and activities of soil enzymes were investigated in the present study. Test bacterial species were Escherichia coli, Bacillus subtilis and Streptococcus aureus. Among the microorganisms tested, S. aureus was the most sensitive. The 50% effects on the inhibition of specific growth rate of E. coli, B. subtilis, and, S. aureus were 555, 18.4, and 15.8 mg Sb L(-1), respectively. A silt loam soil was amended with antimony and incubated in a controlled condition. Microbial activities of dehydrogenase, acid phosphatase (P cycle), arylsulfatase (S cycle), beta-glucosidase (C cycle), urease (N cycle), and fluorescein diacetate hydrolase in soil were measured. Activities of urease and dehydrogenase were related with antimony and can be an early indication of antimony contamination. The maximum increase in soil urease activity by antimony was up to 168% after 3d compared with the control. The activities of other four enzymes (acid phosphatase, fluorescein diacetate hydrolase, arylsulfatase and ss-glucosidase) were less affected by antimony. This study suggested that antimony affects nitrogen cycle in soil by changing urease activity under the neutral pH, however, soil enzyme activities may not be a good protocol due to their complex response patterns to antimony pollution.

  17. Simultaneous inhibition of acrylamide and hydroxymethylfurfural formation by sodium glutamate microcapsules in an asparagine-glucose model system.

    PubMed

    Wang, Zimeng; Wen, Chao; Shi, Xingbo; Lu, Dai; Deng, Jiehong; Deng, Fangming

    2017-02-01

    Inhibiting the formation of acrylamide (AA) and hydroxymethylfurfural (HMF) during food heating processes has attracted considerable investigative efforts due to potential health concerns associated with these compounds. The main purpose of this work is to demonstrate a strategy to simultaneously inhibit the formation of AA and HMF with sodium glutamate microcapsules selected to confirm the efficacy of this strategy. An asparagine-glucose aqueous model system was prepared containing free sodium glutamate and sodium glutamate microcapsules. Compared to adding free sodium glutamate, the maximum inhibition efficiency for AA and HMF was found to increase by addition of sodium glutamate microcapsules to 19.07 and 84.32%, respectively. Moreover, the kinetics of AA and HMF formation were studied in this model system. The AA inhibition efficiency significantly increased from 6.75 to 60.35% and the HMF inhibition efficiency significantly increased from 5.98 to 79.72% with increasing the reaction time from 25 to 40 min, indicating that the sodium glutamate microcapsules strategy proves to be far superior at prolonged heating times. These findings suggested that this inhibition strategy may provide promising characteristics for a variety of applications in food processing.

  18. Tissue distribution of residual antimony in rats treated with multiple doses of meglumine antimoniate

    PubMed Central

    Coelho, Deise Riba; Miranda, Elaine Silva; Saint’Pierre, Tatiana Dillenburg; Paumgartten, Francisco José Roma

    2014-01-01

    Meglumine antimoniate (MA) and sodium stibogluconate are pentavalent antimony (SbV) drugs used since the mid-1940s. Notwithstanding the fact that they are first-choice drugs for the treatment of leishmaniases, there are gaps in our knowledge of their toxicological profile, mode of action and kinetics. Little is known about the distribution of antimony in tissues after SbV administration. In this study, we evaluated the Sb content of tissues from male rats 24 h and three weeks after a 21-day course of treatment with MA (300 mg SbV/kg body wt/d, subcutaneous). Sb concentrations in the blood and organs were determined by inductively coupled plasma-mass spectrometry. In rats, as with in humans, the Sb blood levels after MA dosing can be described by a two-compartment model with a fast (t1/2 = 0.6 h) and a slow (t1/2 >> 24 h) elimination phase. The spleen was the organ that accumulated the highest amount of Sb, while bone and thyroid ranked second in descending order of tissues according to Sb levels (spleen >> bone, thyroid, kidneys > liver, epididymis, lungs, adrenals > prostate > thymus, pancreas, heart, small intestines > skeletal muscle, testes, stomach > brain). The pathophysiological consequences of Sb accumulation in the thyroid and Sb speciation in the liver, thyroid, spleen and bone warrant further studies. PMID:25075781

  19. Corrosion inhibition of rapidly solidified Mg-3% Zn-15% Al magnesium alloy with sodium carboxylates

    SciTech Connect

    Daloz, D.; Michot, G.; Rapin, C.; Steinmetz, P.

    1998-06-01

    The ability of sodium linear-saturated carboxylates to protect magnesium alloys against aqueous corrosion was characterized. Electrochemical measurements of polarization resistance and corrosion current showed the inhibition efficiency of these compounds is a function of their concentration and of the length of the aliphatic chain. In every case studied, the efficiency increased with immersion time. At pH 8, the best inhibiting behavior was observed with 0.05 M sodium undecanoate. The potential-pH diagram of magnesium in an aqueous solution containing undecanoate anions was generated based upon the solubility determined for magnesium undecanoate (Mg[CH{sub 3}(CH{sub 2}){sub 9}COO]{sub 2}). According to this diagram, the very low corrosion rate was suspected to result from formation of Mg(CH{sub 3}[CH{sub 2}]{sub 9}COO){sub 2}. Infrared spectrometry carried out on both the synthesized magnesium carboxylate and the product from the magnesium alloy surface after inhibitive treatment confirmed this hypothesis.

  20. Inhibition of sodium current by taurine magnesium coordination compound prevents cesium chloride-induced arrhythmias.

    PubMed

    Yin, Yongqiang; Wen, Ke; Wu, Yanna; Kang, Yi; Lou, Jianshi

    2012-05-01

    The mechanism(s) by which taurine magnesium coordination compound (TMCC) inhibits experimental arrhythmias remains poorly understood. The purpose of this study was to observe the effects of TMCC against cesium chloride-induced arrhythmia in the rabbit heart and find whether the antiarrhythmic activity is related to inhibition of sodium current. Early afterdepolarization was induced by 1.5 mM cesium chloride (1 ml kg(-1)) through intravenous injection. The monophasic action potentials (MAP) and electrocardiograms were simultaneously recorded. The effect of TMCC on functional refractory periods (FRPs) in the left atrium was also observed in vitro. Arrhythmias onset was significantly retarded by TMCC. The number of ventricular premature contractions and incidence of monophasic ventricular tachycardia and polyphasic ventricular tachycardia in 10 min were decreased by TMCC. These effects can be abolished by veratridine (10 μg kg(-1)). MAP duration at 90% repolarization was significantly prolonged by TMCC, which can be prolonged even longer by veratridine (10 μg kg(-1)). In vitro experiments showed that FRPs was prolonged by TMCC which can be cancelled by veratridine (10 μg kg(-1)). TMCC prevents cesium chloride-induced arrhythmias, and inhibition of sodium current, in part, contributes to the antiarrhythmic effect of TMCC.

  1. Sodium caprate augments the hypoglycemic effect of berberine via AMPK in inhibiting hepatic gluconeogenesis.

    PubMed

    Zhang, Ming; Lv, Xiaoyan; Li, Jing; Meng, Zhaojie; Wang, Qiujing; Chang, WenGuang; Li, Wei; Chen, Li; Liu, Yanjun

    2012-11-05

    Berberine (BER), a natural product and active ingredient of genera Berberis and Coptis, has been demonstrated to possess anti-diabetic activities. However, the poor bioavailability of this agent greatly limits its clinical application. In our previous study, we demonstrated that co-administration of sodium caprate, an absorption enhancer, with BER could significantly increase the bioavailability of BER without any serious mucosal damage. Here, we investigated the effects of BER on AMP-activated protein kinase (AMPK)/gluconeogenesis pathway and the effects of sodium caprate on hypoglycemic action of BER. The ability of BER co-administered with sodium caprate to reduce insulin resistance was investigated in diabetic rat model induced by high-fat diet and low dose STZ. Western blot was performed to evaluate effects of BER on AMPK signaling proteins involved in hepatic gluconeogenesis in diabetic rat and HepG2 hepatocytes. BER reduced body weight and caused a significant improvement in glucose tolerance without altering food intake in diabetic rats. Similarly, BER reduced plasma triglycerides and improved insulin action in diabetic rats. BER down-regulated the elevated expressions of gluconeogenesis key enzymes PEPCK and G6Pase, inhibited the translocation of TORC2 from cytoplasm to nucleus and increased AMPK activity in liver tissues. The effect of BER was higher when co-administered with sodium caprate. BER treatment resulted in reduced glucose production in HepG2 hepatocytes. BER increased AMPK activity, reduced the expression of PEPCK, and the nuclear transcription factors PGC-1, HNF-4α and FOXO1. The effect of BER on gluconeogenesis could be partly blocked by AMPK inhibitor, Compound C. BER could suppress hepatic gluconeogenesis in rat model of diabetes at least in part via stimulation of AMPK activity and this action of BER is augmented by sodium caprate.

  2. Jingzhaotoxin-I, a novel spider neurotoxin preferentially inhibiting cardiac sodium channel inactivation.

    PubMed

    Xiao, Yucheng; Tang, Jianzhou; Hu, Weijun; Xie, Jinyun; Maertens, Chantal; Tytgat, Jan; Liang, Songping

    2005-04-01

    Jingzhaotoxin-I (JZTX-I), a 33-residue polypeptide, is derived from the Chinese tarantula Chilobrachys jing-zhao venom based on its ability to evidently increase the strength and the rate of vertebrate heartbeats. The toxin has three disulfide bonds with the linkage of I-IV, II-V, and III-VI that is a typical pattern found in inhibitor cystine knot molecules. Its cDNA determined by rapid amplification of 3'- and 5'-cDNA ends encoded a 62-residue precursor with a small proregion of eight residues. Whole-cell configuration indicated that JZTX-I was a novel neurotoxin preferentially inhibiting cardiac sodium channel inactivation by binding to receptor site 3. Although JZTX-I also exhibits the interaction with channel isoforms expressing in mammalian and insect sensory neurons, its affinity for tetrodotoxin-resistant subtype in mammalian cardiac myocytes (IC50 = 31.6 nm) is approximately 30-fold higher than that for tetrodotoxin-sensitive subtypes in latter tissues. Not affecting outward delay-rectified potassium channels expressed in Xenopus laevis oocytes and tetrodotoxin-resistant sodium channels in mammal sensory neurons, JZTX-I hopefully represents a potent ligand to discriminate cardiac sodium channels from neuronal tetrodotoxin-resistant isoforms. Furthermore, different from any reported spider toxins, the toxin neither modifies the current-voltage relationships nor shifts the steady-state inactivation of sodium channels. Therefore, JZTX-I defines a new subclass of spider sodium channel toxins. JZTX-I is an alpha-like toxin first reported from spider venoms. The result provides an important witness for a convergent functional evolution between spider and other animal venoms.

  3. Ferrous iron oxidation by Thiobacillus ferrooxidans: inhibition with benzoic acid, sorbic acid and sodium lauryl sulfate

    SciTech Connect

    Onysko, S.J.

    1984-07-01

    Acid mine drainage is formed by the weathering or oxidation of pyritic material exposed during coal mining. The rate of pyritic material oxidation can be greatly accelerated by certain acidophilic bacteria such as Thiobacillus ferrooxidans which catalyse the oxidation of ferrous to ferric iron. A number of organic compounds, under laboratory conditions, can apparently inhibit both the oxidation of ferrous to ferric iron by T. ferrooxidans and the weathering of pyritic material by mixed cultures of acid mine drainage micro-organisms. Sodium lauryl sulphate (SLS), an anionic surfactant has proved effective in this respect. Benzoic acid, sorbic acid and SLS at low concentrations, each effectively inhibited bacterial oxidation of ferrous iron in batch cultures of T. ferrooxidans. The rate of chemical oxidation of ferrous iron in low pH, sterile, batch reactors was not substantially affected at the tested concentrations of any of the compounds.

  4. Inhibition of ATPase activity in the freshwater fish Labeo rohita (Hamilton) exposed to sodium cyanide.

    PubMed

    Dube, Praveen N; Hosetti, Basaling B

    2011-10-01

    Present study concerns the effect of sodium cyanide on the Indian major carp, Labeo rohita. Fishes were exposed to lethal (0.32 mg/L) and sublethal (0.064 mg/L) concentrations of sodium cyanide. The effect of intoxication was studied on Na(+)K(+)ATPase, Mg(+2)ATPase and Ca(2+)ATPase in various physiological tissues (gill, liver, and muscle) at the end of 1, 2, 3 and 4 days of lethal and 5, 10 and 15 days of sublethal exposure periods. Sodium cyanide induced significant inhibitory effects on the ATPase activity of the fish. Inhibition of the ATPase blocked the active transport system of the gill epithelial as well as chloride cells, and thus altered the osmo-regulatory mechanism of the fish. The value of the measured responses as an indicator of stress caused by water contamination discussed. The results confirm that ATPase levels significantly decreased in treated fish, indicating that ATPases could be used as sensitive and useful biomarkers for cyanide pollution.

  5. Plant-derived polysaccharide supplements inhibit dextran sulfate sodium-induced colitis in the rat.

    PubMed

    Koetzner, Lee; Grover, Gary; Boulet, Jamie; Jacoby, Henry I

    2010-05-01

    Several plant-derived polysaccharides have been shown to have anti-inflammatory activity in animal models. Ambrotose complex and Advanced Ambrotose are dietary supplements that include aloe vera gel, arabinogalactan, fucoidan, and rice starch, all of which have shown such activity. This study was designed to evaluate these formulations against dextran sulfate sodium (DSS)-induced colitis in rats and to confirm their short-term safety after 14 days of daily dosing. Rats were dosed daily orally with vehicle, Ambrotose or Advanced Ambrotose. On day six groups of rats received tap water or 5% Dextran Sulfate sodium. Ambrotose and Advanced Ambrotose significantly lowered the disease scores and partially prevented the shortening of colon length. An increase in monocyte count was induced by dextran sulfate sodium and inhibited by Ambrotose and Advanced Ambrotose. There were no observable adverse effects after 14-day daily doses. The mechanism of action of the formulations against DSS-induced colitis may be related to its effect on monocyte count.

  6. Plant-Derived Polysaccharide Supplements Inhibit Dextran Sulfate Sodium-Induced Colitis in the Rat

    PubMed Central

    Koetzner, Lee; Grover, Gary; Boulet, Jamie

    2009-01-01

    Several plant-derived polysaccharides have been shown to have anti-inflammatory activity in animal models. Ambrotose complex and Advanced Ambrotose are dietary supplements that include aloe vera gel, arabinogalactan, fucoidan, and rice starch, all of which have shown such activity. This study was designed to evaluate these formulations against dextran sulfate sodium (DSS)-induced colitis in rats and to confirm their short-term safety after 14 days of daily dosing. Rats were dosed daily orally with vehicle, Ambrotose or Advanced Ambrotose. On day six groups of rats received tap water or 5% Dextran Sulfate sodium. Ambrotose and Advanced Ambrotose significantly lowered the disease scores and partially prevented the shortening of colon length. An increase in monocyte count was induced by dextran sulfate sodium and inhibited by Ambrotose and Advanced Ambrotose. There were no observable adverse effects after 14-day daily doses. The mechanism of action of the formulations against DSS-induced colitis may be related to its effect on monocyte count. PMID:19513840

  7. Cell volume changes upon sodium pump inhibition in Helix aspersa neurones.

    PubMed Central

    Alvarez-Leefmans, F J; Gamiño, S M; Reuss, L

    1992-01-01

    1. Identified neurones of the suboesophageal ganglia of Helix aspersa were loaded with tetramethylammonium (TMA+). Experimentally induced changes in cell water volume and membrane potential were measured continuously by monitoring changes in intracellular [TMA+] using ion-sensitive double-barrelled microelectrodes. The technique allowed measurements of cell water volume changes of less than 5%. 2. Exposure to hyperosmotic (up to +24%) or hyposmotic (up to about -10%) solutions caused reversible decreases and increases in cell water volume respectively, which agreed with near-ideal osmometric behaviour. Upon exposure to hyposmotic solutions whose osmolality was decreased by 30-40%, the cell water volume increased to maximum values below those expected for ideal osmometric behaviour and exhibited partial regulatory volume decrease. 3. The sodium pump was inhibited in twenty identified neurones by sustained exposure to 1 mM ouabain. In every case ouabain caused cell membrane depolarization, as expected for inhibition of an electrogenic sodium pump. 4. Upon pump inhibition most cells (n = 14) shrank by up to 13% of their initial water volume. In five of these cells, shrinkage was preceded by one or more short-lived swelling phases. In two other neurones short-lived swelling was followed by cell volume recovery without appreciable shrinkage. In four out of the twenty cells, there were no measurable volume changes. 5. The lack of an initial swelling phase in the cells that shrank, as well as the absence of detectable volume changes in some of the neurones, was not due to loss of ion-selective electrode sensitivity since predictable changes in cell volume elicited by osmotic challenges were monitored in the same cells. 6. It is concluded that neurones can be endowed with ouabain-insensitive mechanisms of volume control, whose activation following Na+ pump inhibition prevents them from short-term swelling and lysis. PMID:1338793

  8. Neurosteroid dehydroepiandrosterone sulphate inhibits persistent sodium currents in rat medial prefrontal cortex via activation of sigma-1 receptors.

    PubMed

    Cheng, Zheng-Xiang; Lan, Dan-Mei; Wu, Pei-Ying; Zhu, Yan-Hua; Dong, Yi; Ma, Lan; Zheng, Ping

    2008-03-01

    Dehydroepiandrosterone sulphate is one of the most important neurosteroids. In the present paper, we studied the effect of dehydroepiandrosterone sulphate on persistent sodium currents and its mechanism and functional consequence with whole-cell patch clamp recording method combined with a pharmacological approach in the rat medial prefrontal cortex slices. The results showed that dehydroepiandrosterone sulphate inhibited the amplitude of persistent sodium currents and the inhibitory effect was significant at 0.1 microM, reached maximum at 1 microM and decreased with the increase in the concentrations of above 1 microM. The effect of dehydroepiandrosterone sulphate on persistent sodium currents was canceled by the Gi protein inhibitor and the protein kinase C inhibitor, but not by the protein kinase A inhibitor. The effect of dehydroepiandrosterone sulphate on persistent sodium currents was also canceled by the sigma-1 receptor blockers and the sigma-1 receptor agonist could mimic the effect of dehydroepiandrosterone sulphate. Dehydroepiandrosterone sulphate had no significant influence on neuronal excitability but could significantly inhibit chemical inhibition of mitochondria-evoked increase in persistent sodium currents. These results suggest that dehydroepiandrosterone sulphate inhibits persistent sodium currents via the activation of sigma-1 receptors-Gi protein-protein kinase C-coupled signaling pathway, and the main functional consequence of this effect of DHEAS is presumably to protect neurons under ischemia.

  9. How Sodium Chloride Salt Inhibits the Formation of CO2 Gas Hydrates.

    PubMed

    Holzammer, Christine; Finckenstein, Agnes; Will, Stefan; Braeuer, Andreas S

    2016-03-10

    We present an experimental Raman study on how the addition of sodium chloride to CO2-hydrate-forming systems inhibits the hydrate formation thermodynamically. For this purpose, the molar enthalpy of reaction and the molar entropy of reaction for the reaction of weakly hydrogen-bonded water molecules to strongly hydrogen bonded water molecules are determined for different salinities from the Raman spectrum of the water-stretching vibration. Simultaneously, the influence of the salinity on the solubility of CO2 in the liquid water-rich phase right before the start of hydrate formation is analyzed. The results demonstrate that various mechanisms contribute to the inhibition of gas hydrate formation. For the highest salt concentration of 20 wt % investigated, the temperature of gas hydrate formation is lowered by 12 K. For this concentration the molar enthalpy and entropy of reaction become smaller by 50 and 20%, respectively. Concurrently, the solubility of carbon dioxide is reduced by 70%. These results are compared with data in literature for systems of sodium chloride in water (without carbon dioxide).

  10. Sodium-glucose cotransporter 2 inhibition and cardiovascular risk reduction in patients with type 2 diabetes: the emerging role of natriuresis.

    PubMed

    Rajasekeran, Harindra; Lytvyn, Yuliya; Cherney, David Z I

    2016-03-01

    Inhibition of sodium-glucose cotransporter 2 causes both glycosuria and natriuresis, leading to reductions in hyperglycemia, body weight, blood pressure, and proteinuria. The recently published EMPA-REG OUTCOME study demonstrated significant cardiovascular and mortality benefits of sodium-glucose cotransporter 2 inhibition with empagliflozin in patients with type 2 diabetes and established cardiovascular disease, and may suggest a broader role for sodium-glucose cotransporter 2 inhibition in patients with heart failure.

  11. Pilot testing of sodium thiosulfate for oxidation/scaling inhibition in lime/limestone flue gas desulfurization systems

    SciTech Connect

    Chang, J.C.S.; Brna, T.G.

    1985-01-01

    Pilot plant tests have been conducted to evaluate sodium thiosulfate as an oxidation inhibition additive in five lime/limestone slurry flue gas desulfurization processes. It was found that the oxidation rate of absorbed sulfur dioxide (SO/sub 2/) was reduced by more than 50 percent in the presence of 100 to 200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes.

  12. Antimony activities in copper mattes

    NASA Astrophysics Data System (ADS)

    Hino, M.; Toguri, J. M.

    1987-03-01

    A mass spectrometric technique combined with a double Knudsen cell was used to determine the antimony and copper activities in the Cu-Sb binary system at 1373 K and in the two-melt composition range of the Cu-S-Sb ternary system at 1423 K. The antimony and copper activities were calculated based on the intensity ration of the gaseous Sb and Cu species, over the unknown and known activity samples, respectively. γ{Sb/o} were found to be 1.1×10-2 in molten copper at 1373 K, and 1.8×10-2 and 0.44 in a copper-rich phase and in a matter phase, of the Cu-S-Sb ternary system at 1423 K, respectively. These values indicate, that antimony can be removed during the matte smelting and slagging stage of the copper smelting process. Interaction parameters of antimony in molten copper slagging stage of the copper smelting process. Interaction parameters of antimony in molten copper at 1423 K were calculated and found to be 10.7, -5.4, and 6.3 for ɛ{Sb/Sb} · ρSb Sb, and ɛ{Sb/S}, respectively.

  13. Classification of Drugs Based on Properties of Sodium Channel Inhibition: A Comparative Automated Patch-Clamp Study

    PubMed Central

    Lenkey, Nora; Karoly, Robert; Lukacs, Peter; Vizi, E. Sylvester; Sunesen, Morten; Fodor, Laszlo; Mike, Arpad

    2010-01-01

    Background There is only one established drug binding site on sodium channels. However, drug binding of sodium channels shows extreme promiscuity: ∼25% of investigated drugs have been found to potently inhibit sodium channels. The structural diversity of these molecules suggests that they may not share the binding site, and/or the mode of action. Our goal was to attempt classification of sodium channel inhibitors by measuring multiple properties of inhibition in electrophysiology experiments. We also aimed to investigate if different properties of inhibition correlate with specific chemical properties of the compounds. Methodology/Principal Findings A comparative electrophysiological study of 35 compounds, including classic sodium channel inhibitors (anticonvulsants, antiarrhythmics and local anesthetics), as well as antidepressants, antipsychotics and neuroprotective agents, was carried out using rNav1.2 expressing HEK-293 cells and the QPatch automatic patch-clamp instrument. In the multi-dimensional space defined by the eight properties of inhibition (resting and inactivated affinity, potency, reversibility, time constants of onset and offset, use-dependence and state-dependence), at least three distinct types of inhibition could be identified; these probably reflect distinct modes of action. The compounds were clustered similarly in the multi-dimensional space defined by relevant chemical properties, including measures of lipophilicity, aromaticity, molecular size, polarity and electric charge. Drugs of the same therapeutic indication typically belonged to the same type. We identified chemical properties, which were important in determining specific properties of inhibition. State-dependence correlated with lipophilicity, the ratio of the neutral form of molecules, and aromaticity: We noticed that the highly state dependent inhibitors had at least two aromatic rings, logP>4.0, and pKa<8.0. Conclusions/Significance The correlations of inhibition properties

  14. Computational models for drug inhibition of the human apical sodium-dependent bile acid transporter.

    PubMed

    Zheng, Xiaowan; Ekins, Sean; Raufman, Jean-Pierre; Polli, James E

    2009-01-01

    The human apical sodium-dependent bile acid transporter (ASBT; SLC10A2) is the primary mechanism for intestinal bile acid reabsorption. In the colon, secondary bile acids increase the risk of cancer. Therefore, drugs that inhibit ASBT have the potential to increase the risk of colon cancer. The objectives of this study were to identify FDA-approved drugs that inhibit ASBT and to derive computational models for ASBT inhibition. Inhibition was evaluated using ASBT-MDCK monolayers and taurocholate as the model substrate. Computational modeling employed a HipHop qualitative approach, a Hypogen quantitative approach, and a modified Laplacian Bayesian modeling method using 2D descriptors. Initially, 30 compounds were screened for ASBT inhibition. A qualitative pharmacophore was developed using the most potent 11 compounds and applied to search a drug database, yielding 58 hits. Additional compounds were tested, and their K(i) values were measured. A 3D-QSAR and a Bayesian model were developed using 38 molecules. The quantitative pharmacophore consisted of one hydrogen bond acceptor, three hydrophobic features, and five excluded volumes. Each model was further validated with two external test sets of 30 and 19 molecules. Validation analysis showed both models exhibited good predictability in determining whether a drug is a potent or nonpotent ASBT inhibitor. The Bayesian model correctly ranked the most active compounds. In summary, using a combined in vitro and computational approach, we found that many FDA-approved drugs from diverse classes, such as the dihydropyridine calcium channel blockers and HMG CoA-reductase inhibitors, are ASBT inhibitors.

  15. Computational Models for Drug Inhibition of the Human Apical Sodium-dependent Bile Acid Transporter

    PubMed Central

    Zheng, Xiaowan; Ekins, Sean; Raufman, Jean-Pierre; Polli, James E.

    2009-01-01

    The human apical sodium-dependent bile acid transporter (ASBT; SLC10A2) is the primary mechanism for intestinal bile acid re-absorption. In the colon, secondary bile acids increase the risk of cancer. Therefore, drugs that inhibit ASBT have the potential to increase the risk of colon cancer. The objectives of this study were to identify FDA-approved drugs that inhibit ASBT and to derive computational models for ASBT inhibition. Inhibition was evaluated using ASBT-MDCK monolayers and taurocholate as the model substrate. Computational modeling employed a HipHop qualitative approach, a Hypogen quantitative approach, as well as a modified Laplacian Bayesian modeling method using 2D descriptors. Initially, 30 compounds were screened for ASBT inhibition. A qualitative pharmacophore was developed using the most potent 11 compounds and applied to search a drug database, yielding 58 hits. Additional compounds were tested and their Ki values were measured. A 3D-QSAR and a Bayesian model were developed using 38 molecules. The quantitative pharmacophore consisted of one hydrogen bond acceptor, three hydrophobic features, and five excluded volumes. Each model was further validated with two external test sets of 30 and 19 molecules. Validation analysis showed both models exhibited good predictability in determining whether a drug is a potent or non-potent ASBT inhibitor. The Bayesian model correctly ranked the most active compounds. In summary, using a combined in vitro and computational approach, we found that many FDA-approved drugs from diverse classes, such as the dihydropyridine calcium channel blockers and HMG CoA-reductase inhibitors, are ASBT inhibitors. PMID:19673539

  16. Influence of Antimony-Halogen Additives on Flame Propagation.

    PubMed

    Babushok, Valeri I; Deglmann, Peter; Krämer, Roland; Linteris, Gregory T

    2017-01-01

    A kinetic model for flame inhibition by antimony-halogen compounds in hydrocarbon flames is developed. Thermodynamic data for the relevant species are assembled from the literature, and calculations are performed for a large set of additional species of Sb-Br-C-H-O system. The main Sb- and Br-containing species in the combustion products and reaction zone are determined using flame equilibrium calculations with a set of possible Sb-Br-C-H-O species, and these are used to develop the species and reactions in a detailed kinetic model for antimony flame inhibition. The complete thermodynamic data set and kinetic mechanism are presented. Laminar burning velocity simulations are used to validate the mechanism against available data in the literature, as well as to explore the relative performance of the antimony-halogen compounds. Further analysis of the premixed flame simulations has unraveled the catalytic radical recombination cycle of antimony. It includes (primarily) the species Sb, SbO, SbO2, and HOSbO, and the reactions: Sb+O+M=SbO+M; Sb+O2+M=SbO2+M; SbO+H=Sb+OH; SbO+O=Sb+O2; SbO+OH+M=HOSbO+M; SbO2+H2O=HOSbO+OH; HOSbO+H=SbO+H2O; SbO+O+M=SbO2+M. The inhibition cycles of antimony are shown to be more effective than those of bromine, and intermediate between the highly effective agents CF3Br and trimethylphosphate. Preliminary examination of a Sb/Br gas-phase system did not show synergism in the gas-phase catalytic cycles (i.e., they acted essentially independently).

  17. Sodium Methyldithiocarbamate Exerts Broad Inhibition of Cellular Signaling and Expression of Effector Molecules of Inflammation

    PubMed Central

    Pruett, Stephen B.

    2013-01-01

    Sodium methyldithiocarbamate (SMD) is one of the most abundantly used conventional pesticides in the United States. At dosages relevant to occupational exposure, it causes major effects on the immune system in mice, including a decreased resistance to sepsis. This lab has identified some of the mechanisms of action of this compound and some of the immunological parameters affected, but the global effects have not previously been assessed. The purpose of the present study was to conduct transcriptomic analysis of the effects of SMD on lipopolysaccharide-induced expression of mediators important in innate immunity and inflammation. The results revealed broad effects on expression of transcription factors in both branches of Toll-like receptor 4 (TLR4) signaling (MyD88 and TRIF). However, TLR3 and interferon signaling pathways were decreased to a greater extent, and assessment of the effects of SMD on polyinosinic polycytidylic acid–induced cytokine and chemokine production revealed that these responses mediated by TLR3 were indeed sensitive to the effects of SMD, with inhibition occurring at lower dosages than required to inhibit responses to other immunological stimuli tested in our previous studies. In the downstream signaling pathways of these TLRs, functional analysis also revealed that NF-κB activation was inhibited by SMD, as indicated by gene expression analysis and a reporter construct in mice. A previously unreported effect on luteinizing hormone and follicle-stimulating hormone pathways was also observed. PMID:24056979

  18. Selective inhibition of sweetness by the sodium salt of +/-2-(4-methoxyphenoxy)propanoic acid.

    PubMed

    Schiffman, S S; Booth, B J; Sattely-Miller, E A; Graham, B G; Gibes, K M

    1999-08-01

    The purpose of this study was to determine the degree to which the sodium salt of +/-2-(4-methoxyphenoxy)propanoic acid (Na-PMP) reduced sweet intensity ratings of 15 sweeteners in mixtures. Na-PMP has been approved for use in confectionary/frostings, soft candy and snack products in the USA at concentrations up to 150 p.p.m. A trained panel evaluated the effect of Na-PMP on the intensity of the following 15 sweeteners: three sugars (fructose, glucose, sucrose), three terpenoid glycosides (monoammonium glycyrrhizinate, rebaudioside-A, stevioside), two dipeptide derivatives (alitame, aspartame), two N-sulfonylamides (acesulfame-K, sodium saccharin), two polyhydric alcohols (mannitol, sorbitol), 1 dihydrochalcone (neohesperidin dihydrochalcone), one protein (thaumatin) and one sulfamate (sodium cyclamate). Sweeteners were tested at concentrations isosweet with 2.5, 5, 7.5 and 10% sucrose in mixtures with two levels of Na-PMP: 250 and 500 p.p.m. In addition, the 15 sweeteners were tested either immediately or 30 s after a pre-rinse with 500 p.p.m. Na-PMP. In mixtures, Na-PMP at both the 250 and 500 p.p.m. levels significantly blocked sweetness intensity for 12 of the 15 sweeteners. However, when Na-PMP was mixed with three of the 15 sweeteners (monoammonium glycyrrhizinate, neohesperidin dihydrochalcone and thaumatin), there was little reduction in sweetness intensity. Pre-rinsing with Na-PMP both inhibited and enhanced sweetness with the greatest enhancements found for monoammonium glycyrrhizinate, neohesperidin dihydrochalcone and thaumatin, which were not suppressed by Na-PMP in mixtures. The mixture data suggest that Na-PMP is a selective competitive inhibitor of sweet taste. The finding that pre-treatment can produce enhancement may be due to sensitization of sweetener receptors by Na-PMP.

  19. Mineral Resource of the Month: Antimony

    USGS Publications Warehouse

    Guberman, David E.

    2015-01-01

    Antimony is a lustrous silvery-white semimetal or metalloid. Archaeological and historical studies indicate that antimony and its mineral sulfides have been used by humans for at least six millennia. The alchemist Basil Valentine is sometimes credited with “discovering” the element; he described the extraction of metallic antimony from stibnite in his treatise “The Triumphal Chariot of Antimony,” published sometime between 1350 and 1600. In the early 18th century, Jöns Jakob Berzelius chose the periodic symbol for antimony (Sb) based on stibium, which is the Latin name for stibnite.

  20. Sodium butyrate reverses the inhibition of Krebs cycle enzymes induced by amphetamine in the rat brain.

    PubMed

    Valvassori, Samira S; Calixto, Karen V; Budni, Josiane; Resende, Wilson R; Varela, Roger B; de Freitas, Karolina V; Gonçalves, Cinara L; Streck, Emilio L; Quevedo, João

    2013-12-01

    There is increasing interest in the possibility that mitochondrial impairment may play an important role in bipolar disorder (BD). The Krebs cycle is the central point of oxidative metabolism, providing carbon for biosynthesis and reducing agents for generation of ATP. Recently, studies have suggested that histone deacetylase (HDAC) inhibitors may have antimanic effects. The present study aims to investigate the effects of sodium butyrate (SB), a HDAC inhibitor, on Krebs cycle enzymes activity in the brain of rats subjected to an animal model of mania induced by D-amphetamine (D-AMPH). Wistar rats were first given D-AMPH or saline (Sal) for 14 days, and then, between days 8 and 14, rats were treated with SB or Sal. The citrate synthase (CS), succinate dehydrogenase (SDH), and malate dehydrogenase (MDH) were evaluated in the prefrontal cortex, hippocampus, and striatum of rats. The D-AMPH administration inhibited Krebs cycle enzymes activity in all analyzed brain structures and SB reversed D-AMPH-induced dysfunction analyzed in all brain regions. These findings suggest that Krebs cycle enzymes' inhibition can be an important link for the mitochondrial dysfunction seen in BD and SB exerts protective effects against the D-AMPH-induced Krebs cycle enzymes' dysfunction.

  1. Pharmacodynamic model of sodium-glucose transporter 2 (SGLT2) inhibition: implications for quantitative translational pharmacology.

    PubMed

    Maurer, Tristan S; Ghosh, Avijit; Haddish-Berhane, Nahor; Sawant-Basak, Aarti; Boustany-Kari, Carine M; She, Li; Leininger, Michael T; Zhu, Tong; Tugnait, Meera; Yang, Xin; Kimoto, Emi; Mascitti, Vincent; Robinson, Ralph P

    2011-12-01

    Sodium-glucose co-transporter-2 (SGLT2) inhibitors are an emerging class of agents for use in the treatment of type 2 diabetes mellitus (T2DM). Inhibition of SGLT2 leads to improved glycemic control through increased urinary glucose excretion (UGE). In this study, a biologically based pharmacokinetic/pharmacodynamic (PK/PD) model of SGLT2 inhibitor-mediated UGE was developed. The derived model was used to characterize the acute PK/PD relationship of the SGLT2 inhibitor, dapagliflozin, in rats. The quantitative translational pharmacology of dapagliflozin was examined through both prospective simulation and direct modeling of mean literature data obtained for dapagliflozin in healthy subjects. Prospective simulations provided time courses of UGE that were of consistent shape to clinical observations, but were modestly biased toward under prediction. Direct modeling provided an improved characterization of the data and precise parameter estimates which were reasonably consistent with those predicted from preclinical data. Overall, these results indicate that the acute clinical pharmacology of SGLT2 inhibitors in healthy subjects can be reasonably well predicted from preclinical data through rational accounting of species differences in pharmacokinetics, physiology, and SGLT2 pharmacology. Because these data can be generated at the earliest stages of drug discovery, the proposed model is useful in the design and development of novel SGLT2 inhibitors. In addition, this model is expected to serve as a useful foundation for future efforts to understand and predict the effects of SGLT2 inhibition under chronic administration and in other patient populations.

  2. Sodium glucose transporter-2 inhibition has no renoprotective effects on non-diabetic chronic kidney disease.

    PubMed

    Ma, Qiuyue; Steiger, Stefanie; Anders, Hans-Joachim

    2017-04-01

    Sodium glucose transporter (SGLT)-2 inhibition has renoprotective effects in diabetic kidney disease. Whether similar effects can be achieved also in non-diabetic kidney disease is speculative. Chronic kidney disease was induced in C57BL/6N mice by feeding an oxalate-rich diet for 14 days, known to induce nephrocalcinosis-related tubular atrophy and interstitial fibrosis without directly affecting the glomerular compartment. Empagliflozin treatment started from day 0 of oxalate feeding had no effect on the decline of glomerular filtration rate, crystal deposition, blood urea nitrogen or serum creatinine levels on day 7 and 14. Tissue morphometry of tubular injury and kidney mRNA levels of kidney injury molecule-1 or tissue inhibitor of metalloproteinase-2 were comparable between empagliflozin- and vehicle-treated mice with oxalate nephropathy on day 7 and 14. Similarly, empagliflozin did not affect markers of interstitial fibrosis, including silver, alpha smooth muscle actin (αSMA) and collagen 1 staining, and mRNA levels of fibronectin-1, collagen 1α1, fibroblast-specific protein-1, and transforming growth factor (TGF)-β2 on day 7 and 14. Thus, the specific renoprotective mechanisms-of-action of SGLT2 inhibition in diabetic kidney disease do not apply to chronic oxalosis, a non-diabetic form of chronic kidney disease.

  3. Project Overview: Inhibition of the Sodium-Iodide Symporter by Perchlorate: Evaluation of Lifestage Sensitivity Using PBPK Modeling

    EPA Science Inventory

    Perchlorate (ClO4-) competitively inhibits uptake of iodide by the sodium-iodide symporter (NIS) in laboratory animals and humans. NIS is found in many tissues, but is primarily responsible for sequestering iodide into the thyroid, enabling biosynthesis of thyroid hormones. The N...

  4. Inhibition of several enzymes by gold compounds. II. beta-Glucuronidase, acid phosphatase and L-malate dehydrogenase by sodium thiomalatoraurate (I), sodium thiosulfatoaurate (I) and thioglucosoaurate (I).

    PubMed

    Lee, M T; Ahmed, T; Haddad, R; Friedman, M E

    1989-01-01

    Bovine liver beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32), wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) and bovine liver L-malate dehydrogenase (L-malate: NAD oxidoreductase, EC 1.1.1.37) were inhibited by a series of gold (I) complexes that have been used as anti-inflammatory drugs. Both sodium thiosulfatoaurate (I) (Na AuTs) and sodium thiomalatoraurate (NaAuTM) effectively inhibited all three enzymes, while thioglucosoaurate (I) (AuTG) only inhibited L-malate dehydrogenase. The equilibrium constants (K1) ranged from nearly 4000 microM for the NaAuTM-beta-glucuronidase interaction to 24 microM for the NaAuTS-beta-glucuronidase interaction. The rate of covalent bond formation (kp) ranged from 0.00032 min-1 for NaAuTM-beta-glucuronidase formation to 1.7 min-1 for AuTG-L-malate dehydrogenase formation. The equilibrium data shows that the gold (I) drugs bind by several orders lower than the gold (III) compounds, suggesting a significantly stronger interaction between the more highly charged gold ion and the enzyme. Yet the rate of covalent bond formation depends as much on the structure of the active site as upon the lability of the gold-ligand bond. It was also observed that the more effective the gold inhibition the more toxic the compound.

  5. Partial Inhibition of Sodium/Calcium Exchange Restores Cellular Calcium Handling in Canine Heart Failure

    PubMed Central

    Hobai, Ion A.; Maack, Christoph; O'Rourke, Brian

    2009-01-01

    Sodium/calcium (Na+/Ca2+) exchange (NCX) overexpression is common to human heart failure and heart failure in many animal models, but its specific contribution to the cellular Ca2+ ([Ca2+]i) handling deficit is unclear. Here, we investigate the effects of exchange inhibitory peptide (XIP) on Ca2+ handling in myocytes isolated from canine tachycardic pacing-induced failing hearts. Whole-cell patch-clamped left ventricular myocytes from failing hearts (F) showed a 52% decrease in steady-state sarcoplasmic reticulum (SR) Ca2+ load and a 44% reduction in the amplitude of the [Ca2+]i transient, as compared with myocytes from normal hearts (N). Intracellular application of XIP (30 μmol/L) normalized the [Ca2+]i transient amplitude in F (3.86-fold increase), concomitant with a similar increase in SR Ca2+ load. The degree of NCX inhibition at this concentration of XIP was ≈27% and was selective for NCX: L-type Ca2+ currents and plasmalemmal Ca2+ pumps were not affected. XIP also indirectly improved the rate of [Ca2+]i removal at steady-state, secondary to Ca2+-dependent activation of SR Ca2+ uptake. The findings indicate that in the failing heart cell, NCX inhibition can improve SR Ca2+ load by shifting the balance of Ca2+ fluxes away from trans-sarcolemmal efflux toward SR accumulation. Hence, inhibition of the Ca2+ efflux mode of the exchanger could potentially be an effective therapeutic strategy for improving contractility in congestive heart failure. PMID:15217911

  6. Inhibition of frog skeletal muscle sodium channels by newly synthesized chiral derivatives of mexiletine and tocainide.

    PubMed

    De Luca, A; Natuzzi, F; Falcone, G; Duranti, A; Lentini, G; Franchini, C; Tortorella, V; Camerino, D C

    1997-12-01

    To search for potent use-dependent blockers of skeletal muscle sodium channels as potential antimyotonic agents, the actions of newly synthesized chiral analogs of mexiletine and tocainide were tested in vitro on sodium currents of single fibers of frog semitendinosus muscle by vaseline-gap voltage clamp method. The effect of each drug on the maximal peak Na+ transient (I(Na) max) was evaluated as both tonic and use-dependent block by using infrequent depolarizing stimulation and trains of pulses at 2-10 Hz frequency, respectively. The mexiletine analog 3-(2,6-dimethylphenoxy)-2-methylpropanamine (Me2), having an increased distance between the phenyl and the amino groups, was less potent than mexiletine in producing a tonic block but produced a remarkable use-dependent block. In fact, the half-maximal concentration (IC50) for tonic block of S(-)-Me2 was 108 microM vs. 54.5 microM of R(-)-mexiletine, but the IC50 was 6.2 times lowered by the 10 Hz stimulation with respect to the 2.4 fold decrease observed with mexiletine. The R(-)-mexiletine and the S(-)-Me2 were about twofold more potent than the corresponding enantiomers in producing a tonic block, but the stereoselectivity attenuated during use-dependent blockade. The more lipophilic 2-(4-chloro-2-methylphenoxy)-1-phenylethylamine (Me1), presently available as raceme, produced a potent and irreversible tonic block of the sodium currents with an IC50 of 29 microM, but had a less pronounced use-dependent inhibition, with a 1.9 fold decrease of the IC50 at 10 Hz. The R(-) isomer of 2',6'-valinoxylidide (To1), a tocainide derivative with an increased hindrance on the chiral carbon atom, was twofold (IC50 = 209 microM) and tenfold (IC50 = 27.4 microM) more potent than R(-)-tocainide in tonic and use-dependent block, respectively. Tocainide was almost devoid of stereoselectivity, whereas the eudismic ratio of To1 [(IC50 S(+)-To1/IC50 R(-)-To1] was 1.7. As for mexiletine and Me2, the stereoselectivity of To1 was the

  7. Human serum paraoxonase-1 (hPON1): in vitro inhibition effects of moxifloxacin hydrochloride, levofloxacin hemihidrate, cefepime hydrochloride, cefotaxime sodium and ceftizoxime sodium.

    PubMed

    Türkeş, Cüneyt; Söyüt, Hakan; Beydemir, Şükrü

    2015-01-01

    In this study, we investigated the effects of antibacterial drugs (moxifloxacin hydrochloride, levofloxacin hemihidrate, cefepime hydrochloride, cefotaxime sodium and ceftizoxime sodium) on human serum paraoxonase-1 (hPON1) enzyme activity from human serum in vitro conditions. For this purpose, hPON1 enzyme was purified from human serum using simple chromatographic methods. The antibacterial drugs exhibited inhibitory effects on hPON1 at low concentrations. Ki constants were calculated to be 2.641 ± 0.040 mM, 5.525 ± 0.817 mM, 35.092 ± 1.093 mM, 252.762 ± 5.749 mM and 499.244 ± 10.149 mM, respectively. The inhibition mechanism of moxifloxacin hydrochloride was competitive, whereas levofloxacin hemihidrate, cefepime hydrochloride, cefotaxime sodium and ceftizoxime sodium were noncompetitive inhibitors.

  8. Synergy between chronic corticosterone and sodium azide treatments in producing a spatial learning deficit and inhibiting cytochrome oxidase activity.

    PubMed Central

    Bennett, M C; Mlady, G W; Fleshner, M; Rose, G M

    1996-01-01

    Previously, we developed a rat model of persistent mitochondrial dysfunction based upon the chronic partial inhibition of the mitochondrial enzyme cytochrome oxidase (EC 1.9.3.1). Continuous systemic infusion of sodium azide at approximately 1 mg/kg per hr inhibited cytochrome oxidase activity and produced a spatial learning deficit. In other laboratories, glucocorticoids have been reported to exacerbate neuronal damage from various acute metabolic insults. Therefore, we tested the hypothesis that corticosterone, the primary glucocorticoid in the rat, would potentiate the sodium azide-induced learning deficit. To this end, we first identified nonimpairing doses of sodium azide (approximately 0.75 mg/kg per hr) and corticosterone (100-mg pellet, 3-week sustained-release). We now report that chronic co-administration of these individually nonimpairing treatments produced a severe learning deficit. Moreover, the low dose of corticosterone, which did not elevate serum corticosterone, acted synergistically with sodium azide to inhibit cytochrome oxidase activity. The latter result represents a previously unidentified effect of glucocorticoids that provides a candidate mechanism for glucocorticoid potentiation of neurotoxicity induced by metabolic insult. These results may have the clinical implication of expanding the definition of hypercortisolism in patient populations with compromised oxidative metabolism. Furthermore, they suggest that glucocorticoid treatment may contribute to pathology in disease or trauma conditions that involve metabolic insult. PMID:8577764

  9. SKF-96365 strongly inhibits voltage-gated sodium current in rat ventricular myocytes.

    PubMed

    Chen, Kui-Hao; Liu, Hui; Yang, Lei; Jin, Man-Wen; Li, Gui-Rong

    2015-06-01

    SKF-96365 (1-(beta-[3-(4-methoxy-phenyl) propoxy]-4-methoxyphenethyl)-1H-imidazole hydrochloride) is a general TRPC channel antagonist commonly used to characterize the potential functions of TRPC channels in cardiovascular system. Recent reports showed that SKF-96365 induced a reduction in cardiac conduction. The present study investigates whether the reduced cardiac conduction caused by SKF-96365 is related to the blockade of voltage-gated sodium current (I Na) in rat ventricular myocytes using the whole-cell patch voltage-clamp technique. It was found that SKF-96365 inhibited I Na in rat ventricular myocytes in a concentration-dependent manner. The compound (1 μM) negatively shifted the potential of I Na availability by 9.5 mV, increased the closed-state inactivation of I Na, and slowed the recovery of I Na from inactivation. The inhibition of cardiac I Na by SKF-96365 was use-dependent and frequency-dependent, and the IC₅₀ was decreased from 1.36 μM at 0.5 Hz to 1.03, 0.81, 0.61, 0.56 μM at 1, 2, 5, 10 Hz, respectively. However, the selective TRPC3 antagonist Pyr3 decreased cardiac I Na by 8.5% at 10 μM with a weak use and frequency dependence. These results demonstrate that the TRPC channel antagonist SKF-96365 strongly blocks cardiac I Na in use-dependent and frequency-dependent manners. Caution should be taken for interpreting the alteration of cardiac electrical activity when SKF-96365 is used in native cells as a TRPC antagonist.

  10. Inhibition of tumour necrosis factor-alpha (TNF-alpha) release from mast cells by the anti-inflammatory drugs, sodium cromoglycate and nedocromil sodium.

    PubMed

    Bissonnette, E Y; Enciso, J A; Befus, A D

    1995-10-01

    TNF-alpha is a cytokine thought to be involved in the pathogenesis of asthma and in several other inflammatory conditions. Given recent evidence that mast cells (MC) are an important source of TNF-alpha, we investigated the effects of two anti-inflammatory drugs, nedocromil sodium (NED) and sodium cromoglycate (SCG), on rat MC-derived TNF-alpha. We established that at least 2 h pretreatment with NED or SCG followed by washing was required to inhibit TNF-alpha-dependent cytotoxicity by rat peritoneal MC (PMC). A maximum inhibition of TNF-alpha occurred after 6 h treatment. The inhibitory effect of NED and SCG (10(-5)-10(-3)M) was concentration-dependent (20-37% for NED and 16-37% for SCG). The time-course analysis and the use of cycloheximide, an inhibitor of protein synthesis, provided strong evidence that new protein synthesis by the MC is required for this inhibitory effect. Furthermore, 24 h treatment with 1 mM NED inhibited the levels of mRNA for TNF-alpha by 59-83%. In addition to the effect on TNF-alpha-dependent cytotoxicity by MC, 20 min pretreatment with 10(-4) M NED and SCG inhibited antigen-stimulated TNF-alpha release (6h) by 42% and 48%, respectively. Interestingly, the functionally distinct intestinal mucosal MC (IMMC) is unresponsive to these drugs with regard to histamine secretion. However, as with PMC, 2h pretreatment with NED or SCG inhibited TNF-alpha-dependent cytotoxicity by IMMC. These effects may be important in the action of these drugs in vivo in the late phase reaction in asthma or other inflammatory conditions.

  11. Inhibition of tumour necrosis factor-alpha (TNF-alpha) release from mast cells by the anti-inflammatory drugs, sodium cromoglycate and nedocromil sodium.

    PubMed Central

    Bissonnette, E Y; Enciso, J A; Befus, A D

    1995-01-01

    TNF-alpha is a cytokine thought to be involved in the pathogenesis of asthma and in several other inflammatory conditions. Given recent evidence that mast cells (MC) are an important source of TNF-alpha, we investigated the effects of two anti-inflammatory drugs, nedocromil sodium (NED) and sodium cromoglycate (SCG), on rat MC-derived TNF-alpha. We established that at least 2 h pretreatment with NED or SCG followed by washing was required to inhibit TNF-alpha-dependent cytotoxicity by rat peritoneal MC (PMC). A maximum inhibition of TNF-alpha occurred after 6 h treatment. The inhibitory effect of NED and SCG (10(-5)-10(-3)M) was concentration-dependent (20-37% for NED and 16-37% for SCG). The time-course analysis and the use of cycloheximide, an inhibitor of protein synthesis, provided strong evidence that new protein synthesis by the MC is required for this inhibitory effect. Furthermore, 24 h treatment with 1 mM NED inhibited the levels of mRNA for TNF-alpha by 59-83%. In addition to the effect on TNF-alpha-dependent cytotoxicity by MC, 20 min pretreatment with 10(-4) M NED and SCG inhibited antigen-stimulated TNF-alpha release (6h) by 42% and 48%, respectively. Interestingly, the functionally distinct intestinal mucosal MC (IMMC) is unresponsive to these drugs with regard to histamine secretion. However, as with PMC, 2h pretreatment with NED or SCG inhibited TNF-alpha-dependent cytotoxicity by IMMC. These effects may be important in the action of these drugs in vivo in the late phase reaction in asthma or other inflammatory conditions. Images Fig. 6 PMID:7554404

  12. Poly(vinyl alcohol)/sodium alginate/layered silicate based nanofibrous mats for bacterial inhibition.

    PubMed

    Li, Wei; Li, Xueyong; Chen, Yang; Li, Xiaoxia; Deng, Hongbing; Wang, Ting; Huang, Rong; Fan, Gang

    2013-02-15

    Poly(vinyl alcohol) (PVA)/sodium alginate (ALG)/organic rectorite (OREC) composite nanofibrous mats are fabricated by electrospinning aqueous solutions with different mixing ratios. Both good fiber shape and three-dimensional structure of nanofibrous mats can be observed by Field Emission Scanning Electron Microscopy. Energy-dispersive X-ray spectroscopy shows the existence of OREC in the as-spun composite mats. In addition, small-angle X-ray diffraction confirms that the interlayer of OREC is intercalated by ALG/PVA chains, and the distance between OREC interlayers is increased from 4.50 to 4.74 nm. Wide angle X-ray diffraction and Fourier transform infrared spectra further verify the intercalation is between polymers and layered silicate. Moreover, the thermal gravimetric analysis shows that the addition of OREC has only a small effect on the thermal stability of composites. Furthermore, the antibacterial experiments illustrate that OREC can enhance the bacterial inhibition ability of nanofibrous mats against Escherichia coli and Staphylococcus aureus.

  13. The mechanism by which cytoplasmic protons inhibit the sodium-calcium exchanger in guinea-pig heart cells.

    PubMed Central

    Doering, A E; Lederer, W J

    1993-01-01

    1. We recorded cardiac sodium-calcium exchange current (INa-Ca) in giant excised membrane patches obtained from cardiac myocytes of the adult guinea-pig. 2. Rapid changes in ion concentrations on the cytoplasmic side of the excised membrane patch were produced using a modified oil-gate bath. 3. Sodium-calcium exchange current was activated by step increases in sodium concentration on the cytoplasmic side of the membrane ([Na+]i), which led to an increase in outward INa-Ca to a new steady-state level. The [Na+]i required to half-maximally activate the sodium-calcium exchange current (K1/2) was 21 mM. 4. Step increases in cytoplasmic calcium concentration ([Ca2+]i) stimulated the [Na+]i-activated INa-Ca up to 1 microM [Ca2+]i, then inhibited the exchange current at very high [Ca2+]i (1 mM). 5. A step decrease in cytoplasmic pH from 7.2 to 6.4 (increase in [H+]i) produced a biphasic but monotonic decrease in INa-Ca. Alkalinization of cytoplasmic pH from 7.2 to 8.0 caused a large, biphasic increase in INa-Ca. 6. When INa-Ca was activated by a step increase in [Na+]i and [H+]i was simultaneously increased, the outward current rose to a peak and then declined to a low steady level. The peak current seen was always less than the maximum current produced by an identical elevation of [Na+]i at constant pHi. This reduction in peak outward current reflected a rapid 'primary' inhibition of the sodium-calcium exchange by protons. The decay of the sodium-calcium exchange current following the peak was slow and corresponded to the time course of the onset of a 'secondary' proton block. 7. Rapid primary inhibition of the sodium-calcium exchanger could also be produced by cytoplasmic acidification in the absence of cytoplasmic sodium. The primary blockade was revealed when a subsequent increase in [Na+]i activated INa-Ca and a smaller peak outward current was observed. Secondary inhibition of the sodium-calcium exchanger was not, however, produced by cytoplasmic acidification in

  14. FIRST REPORT ON OTOTOXICITY OF MEGLUMINE ANTIMONIATE

    PubMed Central

    Valete-Rosalino, Cláudia Maria; Araujo-Melo, Maria Helena; Bezerra, Débora Cristina de Oliveira; de Barcelos, Renata Oliveira; de Melo-Ferreira, Vanessa; Torraca, Tânia Salgado de Sousa; Martins, Ana Cristina da Costa; Moreira, João Soares; Vargas, Mirian Catherine Melgares; Braga, Frederico Pereira Bom; Salgueiro, Mariza de Matos; Saheki, Maurício Naoto; Schubach, Armando Oliveira

    2014-01-01

    Introduction: Pentavalent antimonials are the first drug of choice in the treatment of tegumentary leishmaniasis. Data on ototoxicity related with such drugs is scarcely available in literature, leading us to develop a study on cochleovestibular functions. Case Report: A case of a tegumentary leishmaniasis patient, a 78-year-old man who presented a substantial increase in auditory threshold with tinnitus and severe rotatory dizziness during the treatment with meglumine antimoniate, is reported. These symptoms worsened in two weeks after treatment was interrupted. Conclusion: Dizziness and tinnitus had already been related to meglumine antimoniate. However, this is the first well documented case of cochlear-vestibular toxicity related to meglumine antimoniate. PMID:25229226

  15. Experimental and clinical studies with a new antimonial preparation for the treatment of schistosomiasis

    PubMed Central

    Pedrique, Miguel Ron; Ercoli, Nicolò

    1971-01-01

    This paper presents the results of a clinical study in which a new antimony preparation—a chelate of dimethylcysteine with antimony sodium tartrate (”NAP”)—was administered intramuscularly at a total dosage of 2 g (5×400 mg, corresponding to 290 mg of Sb) to 400 patients with schistosomiasis. Among 108 patients in a rural population the treatment was on the whole well accepted (97% completed the intensive course of injections), thus indicating that NAP would be useful for the mass treatment of schistosomiasis. PMID:5317079

  16. Catalytic and inhibiting effects of lithium peroxide and hydroxide on sodium chlorate decomposition

    SciTech Connect

    Cannon, J.C.; Zhang, Y.

    1995-09-01

    Chemical oxygen generators based on sodium chlorate and lithium perchlorate are used in airplanes, submarines, diving, and mine rescue. Catalytic decomposition of sodium chlorate in the presence of cobalt oxide, lithium peroxide, and lithium hydroxide is studied using thermal gravimetric analysis. Lithium peroxide and hydroxide are both moderately active catalysts for the decomposition of sodium chlorate when used alone, and inhibitors when used with the more active catalyst cobalt oxide.

  17. Sodium sulphite inhibition of potato and cherry polyphenolics in nucleic acid extraction for virus detection by RT-PCR.

    PubMed

    Singh, R P; Nie, X; Singh, M; Coffin, R; Duplessis, P

    2002-01-01

    Phenolic compounds from plant tissues inhibit reverse transcription-polymerase chain reaction (RT-PCR). Multiple-step protocols using several additives to inhibit polyphenolic compounds during nucleic acid extraction are common, but time consuming and laborious. The current research highlights that the inclusion of 0.65 to 0.70% of sodium sulphite in the extraction buffer minimizes the pigmentation of nucleic acid extracts and improves the RT-PCR detection of Potato virus Y (PVY) and Potato leafroll virus (PLRV) in potato (Solanum tuberosum) tubers and Prune dwarf virus (PDV) and Prunus necrotic ringspot virus (PNRSV) in leaves and bark in the sweet cherry (Prunus avium) tree. Substituting sodium sulphite in the nucleic acid extraction buffer eliminated the use of proteinase K during extraction. Reagents phosphate buffered saline (PBS)-Tween 20 and polyvinylpyrrolidone (PVP) were also no longer required during RT or PCR phase. The resultant nucleic acid extracts were suitable for both duplex and multiplex RT-PCR. This simple and less expensive nucleic acid extraction protocol has proved very effective for potato cv. Russet Norkotah, which contains a high amount of polyphenolics. Comparing commercially available RNA extraction kits (Catrimox and RNeasy), the sodium sulphite based extraction protocol yielded two to three times higher amounts of RNA, while maintaining comparable virus detection by RT-PCR. The sodium sulphite based extraction protocol was equally effective in potato tubers, and in leaves and bark from the cherry tree.

  18. Inhibition of vacuolation toxin activity of Helicobacter pylori by iodine, nitrite and potentiation by sodium chloride, sterigmatocystin and fluoride.

    PubMed

    Ma, Fengjuan; Zhao, Wenyuan; Kudo, Masanobu; Aoki, Kazuo; Misumi, Junichi

    2002-10-01

    The toxin VacA produced by Helicobacter pylori is an important determinant of virulence. VacA causes vacuolation of cultured cells such as HeLa cells. Iodine, nitrite, sodium chloride, thiocyanate and fungus toxin sterigmatocystin are universally present in nature and could possibly be related to carcinogenesis of the stomach. The present study was designed to examine the effects of the above-mentioned compound on VacA-induced vacuolation of HeLa cells, which was quantitated using the neutral red uptake assay. VacA-induced vacuolation was inhibited by BafA1 and NPPB. Formation of large vacuoles was inhibited in the presence of iodine, nitrite, but enhanced by sodium chloride, thiocyanate, fluoride and sterigmatocystin. Our results indicate that VacA toxin may interact with other gastric cancer risk factors present naturally in the environment, and suggest that those compounds may modulate the development of gastric cancer induced by H. pylori.

  19. Antimony leaching in plastics from waste electrical and electronic equipment (WEEE) with various acids and gamma irradiation.

    PubMed

    Tostar, Sandra; Stenvall, Erik; Boldizar, Antal; Foreman, Mark R St J

    2013-06-01

    There has been a recent interest in antimony since the availability in readily mined areas is decreasing compared to the amounts used. It is important in many applications such as flame retardants and in the production of polyester, which can trigger an investigation of the leachability of antimony from plastics using different acids. In this paper, different types of acids are tested for their ability to leach antimony from a discarded computer housing, made of poly(acrylonitrile butadiene styrene), which is a common plastic type used in electrical and electronic equipment. The acid solutions included sodium hydrogen tartrate (0.5M) dissolved in either dimethyl sulfoxide or water (at ca. 23°C and heated to ca. 105°C). The metal content after leaching was determined by inductively coupled plasma optical emission spectroscopy. The most efficient leaching medium was the heated solution of sodium hydrogen tartrate in dimethyl sulfoxide, which leached almost half of the antimony from the poly(acrylonitrile butadiene styrene). Gamma irradiation, which is proposed to improve the mechanical properties in plastics, was used here to investigate the influence of antimony leaching ability. No significant change in the amount of leached antimony could be observed.

  20. Protective Role of Sodium-Glucose Co-Transporter 2 Inhibition Against Vascular Complications in Diabetes.

    PubMed

    Yamagishi, Sho-ichi; Matsui, Takanori

    2016-04-01

    Diabetic micro- and macroangiopathy are devastating vascular complications that could account for disabilities and high mortality rate in patients with diabetes. Indeed, diabetic nephropathy and retinopathy are the leading causes of end-stage renal failure and acquired blindness, respectively, and atherosclerotic cardiovascular diseases (CVD) accounts for about 60% of death in diabetic subjects. As a result, the average life span of diabetic patients is about 10-15 years shorter than that of non-diabetic subjects. Furthermore, tight blood glucose control might have no more than a marginal impact on CVD in general and on all-cause mortality in particular in diabetes. Therefore, therapeutic strategies that target vascular complications in diabetes need to be developed. Recently, selective inhibition of sodium-glucose co-transporter 2 (SGLT2) has been proposed as a potential therapeutic target for the treatment of patients with diabetes because of low risk of hypoglycemia and no weight gain. Because 90% of glucose filtered by the glomerulus is reabsorbed by a low-affinity/high-capacity SGLT2 expressed in the S1 and S2 segments of the proximal tubule, blockade of SGLT2 promotes urinary glucose excretion and as a result improves hyperglycemia in an insulin-independent manner. Moreover, we have shown that SGLT2-mediated glucose overload to tubular cells could elicit inflammatory and pro-apoptotic reactions in this cell, being directly involved in diabetic nephropathy. In addition, several clinical studies have also shown that SGLT2 inhibitors could reduce blood pressure, body weight, and serum uric acid levels and ameliorate cardiovascular risk in patients with diabetes. This review summarizes the pathophysiological role of SGLT2 in vascular complications in diabetes and its potential therapeutic interventions.

  1. Inhibition of biosynthesis of metalloprotease of Aeromonas sobria by sodium chloride in the medium.

    PubMed

    Takahashi, Eizo; Kobayashi, Hidetomo; Yamanaka, Hiroyasu; Nair, Gopinath Balakrish; Takeda, Yoshifumi; Arimoto, Sakae; Negishi, Tomoe; Okamoto, Keinosuke

    2011-01-01

    The present authors have previously shown that the serine protease activity of Aeromonas sobria is markedly decreased when A. sobria is cultured in medium containing 3.0% sodium chloride (NaCl, concentration almost equivalent to sea water salinity), and that this occurs because, although the synthesis of ASP is not disturbed by the salt in the medium, the maturation pathway of serine protease of A. sobria (ASP) does not proceed successfully in such a medium. In this study, the effect of salt in the medium on the production of metalloprotease by A. sobria (AMP) was examined. A. sobria produced AMP in the milieu when the bacteria were cultured in medium containing (NaCl) at a concentration of 0.5%. However, AMP was not produced when the bacteria were cultured in salty medium containing 1.5% or more NaCl. To examine how NaCl reduces the production of metalloprotease by A. sobria, the amount of amp mRNA in the cell was measured and it was found that this decreased in proportion to the concentration of NaCl in the medium. The mRNA of amp was not detected in cells cultured in medium containing 1.5% or more NaCl. This means that the transcription of amp is inhibited in salty condition. As described, NaCl in the medium disturbs the maturation pathway of ASP. The mode of action whereby NaCl suppresses AMP activity in A. sobria differs from the mechanism for suppressing ASP activity.

  2. Ranolazine inhibits voltage-gated mechanosensitive sodium channels in human colon circular smooth muscle cells.

    PubMed

    Neshatian, Leila; Strege, Peter R; Rhee, Poong-Lyul; Kraichely, Robert E; Mazzone, Amelia; Bernard, Cheryl E; Cima, Robert R; Larson, David W; Dozois, Eric J; Kline, Crystal F; Mohler, Peter J; Beyder, Arthur; Farrugia, Gianrico

    2015-09-15

    Human jejunum smooth muscle cells (SMCs) and interstitial cells of Cajal (ICCs) express the SCN5A-encoded voltage-gated, mechanosensitive sodium channel NaV1.5. NaV1.5 contributes to small bowel excitability, and NaV1.5 inhibitor ranolazine produces constipation by an unknown mechanism. We aimed to determine the presence and molecular identity of Na(+) current in the human colon smooth muscle and to examine the effects of ranolazine on Na(+) current, mechanosensitivity, and smooth muscle contractility. Inward currents were recorded by whole cell voltage clamp from freshly dissociated human colon SMCs at rest and with shear stress. SCN5A mRNA and NaV1.5 protein were examined by RT-PCR and Western blots, respectively. Ascending human colon strip contractility was examined in a muscle bath preparation. SCN5A mRNA and NaV1.5 protein were identified in human colon circular muscle. Freshly dissociated human colon SMCs had Na(+) currents (-1.36 ± 0.36 pA/pF), shear stress increased Na(+) peaks by 17.8 ± 1.8% and accelerated the time to peak activation by 0.7 ± 0.3 ms. Ranolazine (50 μM) blocked peak Na(+) current by 43.2 ± 9.3% and inhibited shear sensitivity by 25.2 ± 3.2%. In human ascending colon strips, ranolazine decreased resting tension (31%), reduced the frequency of spontaneous events (68%), and decreased the response to smooth muscle electrical field stimulation (61%). In conclusion, SCN5A-encoded NaV1.5 is found in human colonic circular smooth muscle. Ranolazine blocks both peak amplitude and mechanosensitivity of Na(+) current in human colon SMCs and decreases contractility of human colon muscle strips. Our data provide a likely mechanistic explanation for constipation induced by ranolazine.

  3. Mechanism of inhibition by chlorpromazine of the human pain threshold sodium channel, Nav1.7.

    PubMed

    Lee, Su-Jin; Kim, Dong-Hyun; Hahn, Sang June; Waxman, Stephen G; Choi, Jin-Sung

    2017-02-03

    Chlorpromazine is a phenothiazine derivative which is primarily used for schizophrenia and occasionally for migraine. Because Nav1.7 plays an important role in pain sensation, we investigated whether chlorpromazine blocks the human Nav1.7 (hNav1.7) sodium current in HEK293 cells stably expressing hNav1.7 using the whole-cell patch-clamp technique. The peak current of hNav1.7 was reduced by chlorpromazine in a concentration-dependent manner with a half-maximal inhibitory concentration of 25.9±0.6μM and a Hill coefficient of 2.3±0.1. The calmodulin inhibitory peptide did not abolish the blockade of hNav1.7 currents by chlorpromazine. The blockade of hNav1.7 currents by chlorpromazine was completely and repeatedly reversible after washout. The half-maximal voltage of activation of hNav1.7 was not changed by chlorpromazine. However, chlorpromazine caused hyperpolarized the steady-state inactivation of hNav1.7. The recovery from inactivation in the presence of chlorpromazine was slower than in the absence of chlorpromazine. Chlorpromazine also showed strong use-dependent inhibition of the hNav1.7 current. Our results demonstrate that chlorpromazine blocks the hNav1.7 current in concentration-, state- and use-dependent manners and suggest that it merits further study for potential use in pain management.

  4. Mineral resource of the month: antimony

    USGS Publications Warehouse

    ,

    2008-01-01

    The article describes the characteristics and industrial uses of antimony. Antimony, which is produced as a byproduct of mining other metals such as gold, lead or silver, is used in everything from flame retardants, batteries, ceramics and glass. It is also used in glass for television picture tubes, computer monitors, pigments and catalysts.

  5. Heteronuclear compounds of arsenic and antimony

    NASA Astrophysics Data System (ADS)

    Mauser, James E.

    1982-09-01

    Volatilization of secondary metals such as arsenic, antimony, and bismuth, during the smelting of copper ores, is important because of environmental and resource considerations. The Bureau of Mines, United States Department of the Interior, has been studying copper concentrate roasting in conjunction with the volatility of these minor constituents. Some unusual vaporization behavior initiated this supplemental paper which shows that when the mixed sulfides of arsenic and antimony are heated, the volatilization of arsenic is retarded and the volatilization of antimony increased. Mixed oxides of arsenic and antimony also exhibit exceptional volatilization behavior. These anomalous vaporization behaviors are attributed to the formation of heteronuclear compounds of arsenic and antimony, but the colligative properties of solutions may also be a factor.

  6. Two cases of visceral leishmaniasis in Colombia resistant to meglumine antimonial treatment.

    PubMed

    Vélez, Iván Darío; Colmenares, Lina María; Muñoz, Carlos Aguirre

    2009-01-01

    Visceral leishmaniasis (VL) affects over 500,000 people worldwide each year. The disease occurs in the Mediterranean basin, Central and South America and is caused by Leishmania infantum (syn L. chagasi). VL is an endemic disease in Colombia, particularly along the Caribbean coast and the Magdalena River Valley and 90% of VL cases occur in children under the age of five. The first line of treatment is chemotherapy with pentavalent antimonial compounds, including sodium stibogluconate (Pentostam) and meglumine antimoniate (Glucantime). These compounds are the ones most used in Colombia, at a dose of 20 mg/kg/day for 28 days. Nevertheless resistance of L. infantum to pentavalent antimonials is becoming an important problem. No cases of VL resistant to pentavalent antimonial compounds have previously been reported from Colombia. This report describes the two cases of VL resistance to antimonial compounds in a girl and a boy who did not respond to previous treatment with Pentacarinat and Glucantime regimens but were treated successfully with liposomal amphotericin B. Based on our findings, we recommend liposomal amphotericin B as the first line of treatment for VL due to its low toxicity, shorter administration period and the low price obtained by WHO.

  7. Copper-promoted cementation of antimony in hydrochloric acid system: A green protocol.

    PubMed

    Wu, Lian-Kui; Li, Ying-Ying; Cao, Hua-Zhen; Zheng, Guo-Qu

    2015-12-15

    A new method of recovering antimony in hydrochloric acid system by cementation with copper powder was proposed and carried out at laboratory scale. Thermodynamic analysis and cyclic voltammetry test were conducted to study the cementation process. This is a novel antimony removal technology and quite meets the requirements of green chemistry. The main cement product Cu2Sb is a promising anodic material for lithium and sodium ion battery. And nearly all consumed copper powder are transformed into CuCl which is an important industrial material. The effect of reaction temperature, stoichiometric ratio of Cu to Sb(III), stirring rate and concentration of HCl on the cementation efficiency of antimony were investigated in detail. Optimized cementation condition is obtained at 60 °C for 120 min and stirring rate of 600 rpm with Cu/Sb(III) stoichiometric ratio of 6 in 3 mol L(-1) HCl. At this time, nearly all antimony can be removed by copper powder and the cementation efficiency is over 99%. The structure and morphologies of the cement products were characterized by X-ray diffraction and scanning electron microscopy, respectively. Results show that the reaction temperature has little influence on the morphology of the cement products which consist of particles with various sizes. The activation energy of the cementation antimony on copper is 37.75 kJ mol(-1), indicating a chemically controlled step. Inductively coupled plasma mass spectrometry results show that no stibine generates during the cementation process.

  8. Alkali oxide-tantalum, niobium and antimony oxide ionic conductors

    NASA Technical Reports Server (NTRS)

    Roth, R. S.; Brower, W. S.; Parker, H. S.; Minor, D. B.; Waring, J. L.

    1975-01-01

    The phase equilibrium relations of four systems were investigated in detail. These consisted of sodium and potassium antimonates with antimony oxide and tantalum and niobium oxide with rubidium oxide as far as the ratio 4Rb2O:llB2O5 (B=Nb, Ta). The ternary system NaSbO3-Sb2O4-NaF was investigated extensively to determine the actual composition of the body centered cubic sodium antimonate. Various other binary and ternary oxide systems involving alkali oxides were examined in lesser detail. The phases synthesized were screened by ion exchange methods to determine mobility of the mobility of the alkali ion within the niobium, tantalum or antimony oxide (fluoride) structural framework. Five structure types warranted further investigation; these structure types are (1) hexagonal tungsten bronze (HTB), (2) pyrochlore, (3) the hybrid HTB-pyrochlore hexagonal ordered phases, (4) body centered cubic antimonates and (5) 2K2O:3Nb2O5. Although all of these phases exhibit good ion exchange properties only the pyrochlore was prepared with Na(+) ions as an equilibrium phase and as a low porosity ceramic. Sb(+3) in the channel interferes with ionic conductivity in this case, although relatively good ionic conductivity was found for the metastable Na(+) ion exchanged analogs of RbTa2O5F and KTaWO6 pyrochlore phases.

  9. Sodium phenylacetate inhibits adoptive transfer of experimental allergic encephalomyelitis in SJL/J mice at multiple steps.

    PubMed

    Dasgupta, Subhajit; Zhou, You; Jana, Malabendu; Banik, Naren L; Pahan, Kalipada

    2003-04-01

    Experimental allergic encephalomyelitis (EAE) is the animal model for multiple sclerosis. The present study underlines the importance of sodium phenylacetate (NaPA), a drug approved for urea cycle disorders, in inhibiting the disease process of adoptively transferred EAE in female SJL/J mice at multiple steps. Myelin basic protein (MBP)-primed T cells alone induced the expression of NO synthase (iNOS) and the activation of NF-kappaB in mouse microglial cells through cell-cell contact. However, pretreatment of MBP-primed T cells with NaPA markedly inhibited its ability to induce microglial expression of iNOS and activation of NF-kappaB. Consistently, adoptive transfer of MBP-primed T cells, but not that of NaPA-pretreated MBP-primed T cells, induced the clinical symptoms of EAE in female SJL/J mice. Furthermore, MBP-primed T cells isolated from NaPA-treated donor mice were also less efficient than MBP-primed T cells isolated from normal donor mice in inducing iNOS in microglial cells and transferring EAE to recipient mice. Interestingly, clinical symptoms of EAE were much less in mice receiving NaPA through drinking water than those without NaPA. Similar to NaPA, sodium phenylbutyrate, a chemically synthesized precursor of NaPA, also inhibited the disease process of EAE. Histological and immunocytochemical analysis showed that NaPA inhibited EAE-induced spinal cord mononuclear cell invasion and normalized iNOS, nitrotyrosine, and p65 (the RelA subunit of NF-kappaB) expression within the spinal cord. Taken together, our results raise the possibility that NaPA or sodium phenylbutyrate taken through drinking water or milk may reduce the observed neuroinflammation and disease process in multiple sclerosis patients.

  10. Phloridzin inhibits high K+-induced contraction via the inhibition of sodium: glucose cotransporter 1 in rat ileum

    PubMed Central

    KANDA, Hidenori; KANEDA, Takeharu; KAWAGUCHI, Akira; SASAKI, Noriyasu; TAJIMA, Tsuyoshi; URAKAWA, Norimoto; SHIMIZU, Kazumasa; SUZUKI, Hiroetsu

    2017-01-01

    Recent studies have shown that phloridzin, an inhibitor of sodium–glucose cotransporter (SGLT), strongly decreases high K+-induced contraction in phasic muscle, such as tenia coli, but slightly affects tonic muscle, such as trachea . In this study, we examined the inhibitory mechanism of phloridzin on high K+-induced muscle contraction in rat ileum, a phasic muscle. Phloridzin inhibited the high K+-induced contraction in the ileum and the aorta, and the relaxing effect of phloridzin at 1 mM in the ileum was approximately five-fold more potent than that in the aorta. The expression of SGLT1 mRNA in the ileum was higher than that of the aorta. Phloridzin significantly inhibited NADH/NAD ratio and phosphocreatine (PCr) content in the ileum; however, application of pyruvate recovered the inhibition of contraction and PCr content, but had no effect on ratio of NADH/NAD. High K+ increased 2-(N (7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino)-2-deoxyglucose (2-NBDG) uptake in ileal smooth muscle cells, and phloridzin inhibited the increase in a concentration-dependent manner. These results suggest that phloridzin inhibits high K+-induced contraction because of the inhibition of energy metabolism via the inhibition of SGLT1. PMID:28190822

  11. Inhibition studies of soybean (Glycine max) urease with heavy metals, sodium salts of mineral acids, boric acid, and boronic acids.

    PubMed

    Kumar, Sandeep; Kayastha, Arvind M

    2010-10-01

    Various inhibitors were tested for their inhibitory effects on soybean urease. The K(i) values for boric acid, 4-bromophenylboronic acid, butylboronic acid, and phenylboronic acid were 0.20 +/- 0.05 mM, 0.22 +/- 0.04 mM, 1.50 +/- 0.10 mM, and 2.00 +/- 0.11 mM, respectively. The inhibition was competitive type with boric acid and boronic acids. Heavy metal ions including Ag(+), Hg(2+), and Cu(2+) showed strong inhibition on soybean urease, with the silver ion being a potent inhibitor (IC(50) = 2.3 x 10(-8) mM). Time-dependent inhibition studies exhibited biphasic kinetics with all heavy metal ions. Furthermore, inhibition studies with sodium salts of mineral acids (NaF, NaCl, NaNO(3), and Na(2)SO(4)) showed that only F(-) inhibited soybean urease significantly (IC(50) = 2.9 mM). Competitive type of inhibition was observed for this anion with a K(i) value of 1.30 mM.

  12. Inhibition by pregnenolone sulphate, a metabolite of the neurosteroid pregnenolone, of voltage-gated sodium channels expressed in Xenopus oocytes.

    PubMed

    Horishita, Takafumi; Ueno, Susumu; Yanagihara, Nobuyuki; Sudo, Yuka; Uezono, Yasuhito; Okura, Dan; Sata, Takeyoshi

    2012-01-01

    Neurosteroids are known as allosteric modulators of the ligand-gated ion channel superfamily. Voltage-gated sodium channels (Na(v)) play an important role in mediating excitotoxic damages. Here we report the effects of neurosteroids on the function of Na(v), using voltage-clamp techniques in Xenopus oocytes expressed with the Na(v)1.2 α subunit. Pregnenolone sulphate, but not pregnenolone, inhibited sodium currents (I(Na)) at 3 - 100 μmol/L. The suppression of I(Na) by pregnenolone sulphate was due to increased inactivation with little change in activation. These findings suggest that pregnenolone sulphate, a metabolite of pregnenolone, suppresses the function of Na(v) via increased inactivation, which may contribute to the neuroprotection.

  13. An Insight into Sodiation of Antimony from First-Principles Crystal Structure Prediction

    NASA Astrophysics Data System (ADS)

    Caputo, Riccarda

    2016-02-01

    Elemental antimony has recently become an attractive anode material for potential application in rechargeable sodium-ion batteries. I present a first-principles study of the structure-composition dependence of the Na-Sb system for both sodiation and desodiation processes. The enthalpy of reaction of x moles of sodium with the hexagonal structure of antimony reveals several stable crystal structures for 0 < x ≤ 3, with variable composition states for 1.25 < x < 2.75. The direct and reverse reactions pass through similar states in terms of enthalpy of formation and symmetry representation of the corresponding optimized structures, in particular for x = 1 and x = 3, confirming the two known phases, namely NaSb and Na3Sb. The calculations suggest that the optimal composition range for reversible sodiation of antimony is 1 < x ≤ 3, thus avoiding the global minimum at x = 1. This can help to rationalize the structure-composition dependence of the electrochemical performance of antimony in Na-ion batteries.

  14. Lacosamide Inhibition of Nav1.7 Voltage-Gated Sodium Channels: Slow Binding to Fast-Inactivated States.

    PubMed

    Jo, Sooyeon; Bean, Bruce P

    2017-04-01

    Lacosamide is an antiseizure agent that targets voltage-dependent sodium channels. Previous experiments have suggested that lacosamide is unusual in binding selectively to the slow-inactivated state of sodium channels, in contrast to drugs like carbamazepine and phenytoin, which bind tightly to fast-inactivated states. Using heterologously expressed human Nav1.7 sodium channels, we examined the state-dependent effects of lacosamide. Lacosamide induced a reversible shift in the voltage dependence of fast inactivation studied with 100-millisecond prepulses, suggesting binding to fast-inactivated states. Using steady holding potentials, lacosamide block was very weak at -120 mV (3% inhibition by 100 µM lacosamide) but greatly enhanced at -80 mV (43% inhibition by 100 µM lacosamide), where there is partial fast inactivation but little or no slow inactivation. During long depolarizations, lacosamide slowly (over seconds) put channels into states that recovered availability slowly (hundreds of milliseconds) at -120 mV. This resembles enhancement of slow inactivation, but the effect was much more pronounced at -40 mV, where fast inactivation is complete, but slow inactivation is not, than at 0 mV, where slow inactivation is maximal, more consistent with slow binding to fast-inactivated states than selective binding to slow-inactivated states. Furthermore, inhibition by lacosamide was greatly reduced by pretreatment with 300 µM lidocaine or 300 µM carbamazepine, suggesting that lacosamide, lidocaine, and carbamazepine all bind to the same site. The results suggest that lacosamide binds to fast-inactivated states in a manner similar to other antiseizure agents but with slower kinetics of binding and unbinding.

  15. In vitro inhibition of hyaluronidase by sodium copper chlorophyllin complex and chlorophyllin analogs

    PubMed Central

    McCook, John P; Dorogi, Peter L; Vasily, David B; Cefalo, Dustin R

    2015-01-01

    Background Inhibitors of hyaluronidase are potent agents that maintain hyaluronic acid homeostasis and may serve as anti-aging, anti-inflammatory, and anti-microbial agents. Sodium copper chlorophyllin complex is being used therapeutically as a component in anti-aging cosmeceuticals, and has been shown to have anti-hyaluronidase activity. In this study we evaluated various commercial lots of sodium copper chlorophyllin complex to identify the primary small molecule constituents, and to test various sodium copper chlorophyllin complexes and their small molecule analog compounds for hyaluronidase inhibitory activity in vitro. Ascorbate analogs were tested in combination with copper chlorophyllin complexes for potential additive or synergistic activity. Materials and methods For hyaluronidase activity assays, dilutions of test materials were evaluated for hydrolytic activity of hyaluronidase by precipitation of non-digested hyaluronate by measuring related turbidity at 595 nm. High-performance liquid chromatography and mass spectroscopy was used to analyze and identify the primary small molecule constituents in various old and new commercial lots of sodium copper chlorophyllin complex. Results The most active small molecule component of sodium copper chlorophyllin complex was disodium copper isochlorin e4, followed by oxidized disodium copper isochlorin e4. Sodium copper chlorophyllin complex and copper isochlorin e4 disodium salt had hyaluronidase inhibitory activity down to 10 µg/mL. The oxidized form of copper isochlorin e4 disodium salt had substantial hyaluronidase inhibitory activity at 100 µg/mL but not at 10 µg/mL. Ascorbate derivatives did not enhance the hyaluronidase inhibitory activity of sodium copper chlorophyllin. Copper isochlorin e4 analogs were always the dominant components of the small molecule content of the commercial lots tested; oxidized copper isochlorin e4 was found in increased concentrations in older compared to newer lots tested

  16. Antimony and silicon environments in antimony silicate glasses

    SciTech Connect

    Mee, M.; Davies, B.C.; Orman, R.G.; Thomas, M.F.; Holland, D.

    2010-09-15

    Antimony silicate glasses, of general formula xSb{sub 2}O{sub 3}.(1-x)SiO{sub 2} (0.1{<=}x{<=}0.78), have been prepared by melt-quenching and their structures studied using {sup 29}Si MAS NMR spectroscopy, {sup 121}Sb Moessbauer spectroscopy and Raman spectroscopy. Oxidation during melting gives rise to Sb{sup 5+} in concentrations, which increase linearly with x to give a value of {approx}10% when x=0.78. {sup 121}Sb Moessbauer spectra show Moessbauer shifts and quadrupole splittings consistent with Sb{sup 3+} in a [:SbO{sub 3}] trigonal pyramid, similar to that in crystalline Sb{sub 2}O{sub 3}. A broad band in the Raman spectrum at {approx}410 cm{sup -1} is due to the vibrations of such a unit. The dependence of the silicon Q{sup n} speciation on x can be interpreted by the formation of Sb-O-Sb links possibly to form rings of 4 [:SbO{sub 3}] units such as are found in valentinite. - Graphical abstract: Antimony silicate glasses have been shown to contain Sb{sup 3+} in [:SbO{sub 3}] trigonal pyramid units using {sup 121}Sb Moessbauer spectroscopy and Raman spectroscopy. {sup 29}Si magic-angle-spinning NMR has shown silicon Q{sup n} speciation which can be interpreted as formation of rings of 4 [:SbO{sub 3}] units such as are found in valentinite.

  17. Sodium channel-inhibiting drugs and survival of breast, colon and prostate cancer: a population-based study

    PubMed Central

    Fairhurst, Caroline; Watt, Ian; Martin, Fabiola; Bland, Martin; Brackenbury, William J.

    2015-01-01

    Metastasis is the leading cause of cancer-related deaths. Voltage-gated sodium channels (VGSCs) regulate invasion and metastasis. Several VGSC-inhibiting drugs reduce metastasis in murine cancer models. We aimed to test the hypothesis that patients taking VGSC-inhibiting drugs who developed cancer live longer than those not taking these drugs. A cohort study was performed on primary care data from the QResearch database, including patients with breast, bowel or prostate cancer. Cox proportional hazards regression was used to compare the survival from cancer diagnosis of patients taking VGSC-inhibiting drugs with those not exposed to these drugs. Median time to death was 9.7 years in the exposed group and 18.4 years in the unexposed group, and exposure to these medications significantly increased mortality. Thus, exposure to VGSC-inhibiting drugs associates with reduced survival in breast, bowel and prostate cancer patients. This finding is not consistent with the preclinical data. Despite the strengths of this study including the large sample size, the study is limited by missing information on potentially important confounders such as cancer stage, co-morbidities and cause of death. Further research, which is able to account for these confounding issues, is needed to investigate the relationship between VGSC-inhibiting drugs and cancer survival. PMID:26577038

  18. Sodium channel-inhibiting drugs and survival of breast, colon and prostate cancer: a population-based study.

    PubMed

    Fairhurst, Caroline; Watt, Ian; Martin, Fabiola; Bland, Martin; Brackenbury, William J

    2015-11-18

    Metastasis is the leading cause of cancer-related deaths. Voltage-gated sodium channels (VGSCs) regulate invasion and metastasis. Several VGSC-inhibiting drugs reduce metastasis in murine cancer models. We aimed to test the hypothesis that patients taking VGSC-inhibiting drugs who developed cancer live longer than those not taking these drugs. A cohort study was performed on primary care data from the QResearch database, including patients with breast, bowel or prostate cancer. Cox proportional hazards regression was used to compare the survival from cancer diagnosis of patients taking VGSC-inhibiting drugs with those not exposed to these drugs. Median time to death was 9.7 years in the exposed group and 18.4 years in the unexposed group, and exposure to these medications significantly increased mortality. Thus, exposure to VGSC-inhibiting drugs associates with reduced survival in breast, bowel and prostate cancer patients. This finding is not consistent with the preclinical data. Despite the strengths of this study including the large sample size, the study is limited by missing information on potentially important confounders such as cancer stage, co-morbidities and cause of death. Further research, which is able to account for these confounding issues, is needed to investigate the relationship between VGSC-inhibiting drugs and cancer survival.

  19. Inhibition of boric acid and sodium borate on the biological activity of microorganisms in an aerobic biofilter.

    PubMed

    Güneş, Y

    2013-01-01

    The aim of this work was to study the inhibition effect of boric acid and sodium borate on the treatment of boron containing synthetic wastewater by a down flow aerobic fixed bed biofilm reactor at various chemical oxygen demand (COD)/boron ratios (0.47-20.54). The inhibitory effect of boron on activated sludge was evaluated on the basis of COD removal during the experimental period. The biofilter (effective volume = 2.5 L) was filled with a ring of plastic material inoculated with acclimated activated sludge. The synthetic wastewater composed of glucose, urea, KH2PO4, MgSO4, Fe2 SO4, ZnSO4 x 7H20, KCl, CaCl2, and di-sodium tetraborate decahydrate or boric acid (B = 100-2000 mg L(-1)). The biological treatment of boron containing wastewater resulted in a low treatment removal rate due to the reduced microbial activity as a result of toxic effects of high boron concentrations. The decrease in the COD removal rate by the presence of either boric acid or sodium borate was practically indistinguishable. It was observed from the experiments that about 90-95% of COD removal was possible at high COD/boron ratios.

  20. Antimony-doped graphene nanoplatelets

    PubMed Central

    Jeon, In-Yup; Choi, Min; Choi, Hyun-Jung; Jung, Sun-Min; Kim, Min-Jung; Seo, Jeong-Min; Bae, Seo-Yoon; Yoo, Seonyoung; Kim, Guntae; Jeong, Hu Young; Park, Noejung; Baek, Jong-Beom

    2015-01-01

    Heteroatom doping into the graphitic frameworks have been intensively studied for the development of metal-free electrocatalysts. However, the choice of heteroatoms is limited to non-metallic elements and heteroatom-doped graphitic materials do not satisfy commercial demands in terms of cost and stability. Here we realize doping semimetal antimony (Sb) at the edges of graphene nanoplatelets (GnPs) via a simple mechanochemical reaction between pristine graphite and solid Sb. The covalent bonding of the metalloid Sb with the graphitic carbon is visualized using atomic-resolution transmission electron microscopy. The Sb-doped GnPs display zero loss of electrocatalytic activity for oxygen reduction reaction even after 100,000 cycles. Density functional theory calculations indicate that the multiple oxidation states (Sb3+ and Sb5+) of Sb are responsible for the unusual electrochemical stability. Sb-doped GnPs may provide new insights and practical methods for designing stable carbon-based electrocatalysts. PMID:25997811

  1. Antimony-doped graphene nanoplatelets

    NASA Astrophysics Data System (ADS)

    Jeon, In-Yup; Choi, Min; Choi, Hyun-Jung; Jung, Sun-Min; Kim, Min-Jung; Seo, Jeong-Min; Bae, Seo-Yoon; Yoo, Seonyoung; Kim, Guntae; Jeong, Hu Young; Park, Noejung; Baek, Jong-Beom

    2015-05-01

    Heteroatom doping into the graphitic frameworks have been intensively studied for the development of metal-free electrocatalysts. However, the choice of heteroatoms is limited to non-metallic elements and heteroatom-doped graphitic materials do not satisfy commercial demands in terms of cost and stability. Here we realize doping semimetal antimony (Sb) at the edges of graphene nanoplatelets (GnPs) via a simple mechanochemical reaction between pristine graphite and solid Sb. The covalent bonding of the metalloid Sb with the graphitic carbon is visualized using atomic-resolution transmission electron microscopy. The Sb-doped GnPs display zero loss of electrocatalytic activity for oxygen reduction reaction even after 100,000 cycles. Density functional theory calculations indicate that the multiple oxidation states (Sb3+ and Sb5+) of Sb are responsible for the unusual electrochemical stability. Sb-doped GnPs may provide new insights and practical methods for designing stable carbon-based electrocatalysts.

  2. The characteristics of inhibition of histamine release from human lung fragments by sodium cromoglycate, salbutamol and chlorpromazine

    PubMed Central

    Church, Martin K.; Young, Kevin D.

    1983-01-01

    1 Three drugs have been tested for activity against antigen-induced histamine release from passively sensitized human lung fragments after increasing periods of pre-incubation before challenge. 2 After 30 s pre-incubation, sodium cromoglycate inhibited histamine release in the concentration range 0.2-200 μM, producing a maximum inhibition of 33.0%. As the pretreatment period was extended, tolerance developed in a dose-related manner, resulting in a 48.3% and 82.8% loss of activity of the 200 μM dose after 60 min and 19 h pre-incubation, respectively. Tolerance was independent of extracellular calcium and was poorly reversible. Lung tissue desensitized to cromoglycate was cross-tolerant to the related drug, bufrolin, but not to salbutamol or chlorpromazine. 3 In acute studies, salbutamol (0.03-3.0 μM) produced dose-related inhibition of histamine release, with a maximum inhibition of 72.2%. The effect was blocked stereoselectively by 1 μM propranolol, suggesting that it occurred through an interaction with lung β-adrenoceptors. Increasing the pre-incubation time with salbutamol from 30 s to 19 h did not produce tolerance. Inhibition produced by incubation with salbutamol for 19 h was totally prevented when propranolol was added at the beginning of the pre-incubation period, indicating that it resulted from stimulation of β-receptors and not from a non-specific or toxic effect. However, studies of reversibility of effect through washing or late addition of propranolol did indicate some change in the nature of salbutamol inhibition with time. 4 Chlorpromazine was a weak inhibitor of immunological histamine release. A 100 μM concentration was ineffective after 30 s pre-incubation but its activity increased with time. Pre-incubation of lung fragments with this concentration for 1 h or longer, or with a 1 mM dose for a shorter period, provoked histamine release in the absence of antigen. Effects of chlorpromazine were not reversed by washing. 5 The different

  3. Surface complexation of antimony on kaolinite.

    PubMed

    Rakshit, Sudipta; Sarkar, Dibyendu; Datta, Rupali

    2015-01-01

    Geochemical fate of antimony (Sb) - a similar oxyanion as arsenic (As) - in a variety of environment is largely unexplored. Kaolinite is an important, naturally occurring clay mineral in soils and aquifers and is known to control the fate of several contaminants via a multitude of geochemical processes, primarily adsorption. Here we report adsorption of antimony on kaolinite as a function of solution chemistry: initial antimony concentration, pH, ionic strength, and a competing anion. A surface complexation modeling (SCM) approach was undertaken to understand the potential mechanistic implications of sorption envelope data. In the SCM, a multicomponent additive approach, in which kaolinite is assumed to be a (1:1) mixture of quartz (≡SiOH) and gibbsite (≡AlOH), was tested. Results indicated that ionic strength has a minimal effect on antimony adsorption. For the lower initial antimony concentration (4.11 μM), the additive model with binuclear surface complexes on quartz and gibbsite showed a better fit at pH<6, but somewhat under predicted the experimental data above pH 6. At the higher initial antimony concentration (41.1 μM), the sorption envelope was of different shape than the lower load. The additive model, which considered binuclear surface complexes for quartz and gibbsite, resulted in over prediction of the adsorption data at pH>3.5. However, the additive model with binuclear surface complex on quartz and mononuclear surface complex on gibbsite showed an excellent fit of the data. Phosphate greatly influenced antimony adsorption on kaolinite at both low and high antimony loadings, indicating competition for available surface sites.

  4. Tolperisone-type drugs inhibit spinal reflexes via blockade of voltage-gated sodium and calcium channels.

    PubMed

    Kocsis, Pál; Farkas, Sándor; Fodor, László; Bielik, Norbert; Thán, Márta; Kolok, Sándor; Gere, Anikó; Csejtei, Mónika; Tarnawa, István

    2005-12-01

    The spinal reflex depressant mechanism of tolperisone and some of its structural analogs with central muscle relaxant action was investigated. Tolperisone (50-400 microM), eperisone, lanperisone, inaperisone, and silperisone (25-200 microM) dose dependently depressed the ventral root potential of isolated hemisected spinal cord of 6-day-old rats. The local anesthetic lidocaine (100-800 microM) produced qualitatively similar depression of spinal functions in the hemicord preparation, whereas its blocking effect on afferent nerve conduction was clearly stronger. In vivo, tolperisone and silperisone as well as lidocaine (10 mg/kg intravenously) depressed ventral root reflexes and excitability of motoneurons. However, in contrast with lidocaine, the muscle relaxant drugs seemed to have a more pronounced action on the synaptic responses than on the excitability of motoneurons. Whole-cell measurements in dorsal root ganglion cells revealed that tolperisone and silperisone depressed voltage-gated sodium channel conductance at concentrations that inhibited spinal reflexes. Results obtained with tolperisone and its analogs in the [3H]batrachotoxinin A 20-alpha-benzoate binding in cortical neurons and in a fluorimetric membrane potential assay in cerebellar neurons further supported the view that blockade of sodium channels may be a major component of the action of tolperisone-type centrally acting muscle relaxant drugs. Furthermore, tolperisone, eperisone, and especially silperisone had a marked effect on voltage-gated calcium channels, whereas calcium currents were hardly influenced by lidocaine. These data suggest that tolperisone-type muscle relaxants exert their spinal reflex inhibitory action predominantly via a presynaptic inhibition of the transmitter release from the primary afferent endings via a combined action on voltage-gated sodium and calcium channels.

  5. δ ENaC: a novel divergent amiloride-inhibitable sodium channel

    PubMed Central

    Zhao, Run-Zhen; Chen, Zai-Xing; Shetty, Sreerama; Idell, Steven; Matalon, Sadis

    2012-01-01

    The fourth subunit of the epithelial sodium channel, termed delta subunit (δ ENaC), was cloned in human and monkey. Increasing evidence shows that this unique subunit and its splice variants exhibit biophysical and pharmacological properties that are divergent from those of α ENaC channels. The widespread distribution of epithelial sodium channels in both epithelial and nonepithelial tissues implies a range of physiological functions. The altered expression of SCNN1D is associated with numerous pathological conditions. Genetic studies link SCNN1D deficiency with rare genetic diseases with developmental and functional disorders in the brain, heart, and respiratory systems. Here, we review the progress of research on δ ENaC in genomics, biophysics, proteomics, physiology, pharmacology, and clinical medicine. PMID:22983350

  6. Sodium channel-inhibiting drugs and cancer survival: protocol for a cohort study using the CPRD primary care database

    PubMed Central

    Fairhurst, Caroline; Martin, Fabiola; Watt, Ian; Doran, Tim; Bland, Martin

    2016-01-01

    Introduction Voltage-gated sodium channel (VGSC)-inhibiting drugs are commonly used to treat epilepsy and cardiac arrhythmia. VGSCs are also widely expressed in various cancers, including those of the breast, bowel and prostate. A number of VGSC-inhibiting drugs have been shown to inhibit cancer cell proliferation, invasion, tumour growth and metastasis in preclinical models, suggesting that VGSCs may be novel molecular targets for cancer treatment. Surprisingly, we previously found that prior exposure to VGSC-inhibiting drugs may be associated with reduced overall survival in patients with cancer, but we were unable to control for the cause of death or indication for prescription. The purpose of the present study is to interrogate a different database to further investigate the relationship between VGSC-inhibiting drugs and cancer-specific survival. Methods and analysis A cohort study using primary care data from the Clinical Practice Research Datalink database will include patients with diagnosis of breast, bowel and prostate cancer (13 000). The primary outcome will be cancer-specific survival from the date of cancer diagnosis. Cox proportional hazards regression will be used to compare survival of patients taking VGSC-inhibiting drugs (including antiepileptic drugs and class I antiarrhythmic agents) with patients with cancer not taking these drugs, adjusting for cancer type, age and sex. Drug exposure will be treated as a time-varying covariate to account for potential immortal time bias. Various sensitivity and secondary analyses will be performed. Ethics and dissemination The project has been reviewed and approved by the University of York Ethical Review Process. Results will be presented at an international conference and published in open access peer-reviewed journals according to the STROBE and RECORD guidelines. PMID:27601493

  7. Liposomal amphotericin B versus pentavalent antimony salts for visceral Leishmania in children.

    PubMed

    Apa, Hurşit; Devrim, İlker; Bayram, Nuri; Deveci, Reyhan; Demir-Özek, Gülcihan; Cartı, Özgür Umaç

    2013-01-01

    The aim of this study was to investigate the efficacy of a 21-day schedule of liposomal amphotericin B compared to pentavalent antimony salts in the treatment of patients during a first episode of visceral leishmaniasis. In this study, 17 cases of visceral leishmaniasis admitted to Behçet Uz Children's Hospital between January 2005 and April 2012 were reviewed retrospectively. The study group was composed of 11 males (64.7%) and 6 females (35.3%). One group included 11 patients who were treated with pentavalent antimony salts, sodium stibogluconate or meglumine antimoniate, intramuscularly for 28 days. The second group was treated with amphotericin B intravenously at a dosage of 3 mg/kg on days 1-5, 10 and 21 (a cumulative dose of 21 mg/kg/day). While pentavalent antimony salts were found to increase biochemical and hematological findings, liposomal amphotericin B was responsible for rapid recovery in fever and shorter hospital stay. As a result, our study shows the advantages of both medications independent of their costs.

  8. LL202 protects against dextran sulfate sodium-induced experimental colitis in mice by inhibiting MAPK/AP-1 signaling

    PubMed Central

    Zhao, Yue; Hu, Yang; Li, Zhiyu; Guo, Qinglong; Zhao, Kai; Lu, Na

    2016-01-01

    LL202, a newly-synthesized flavonoid derivative, has been reported to inhibit inflammatory-induced angiogenesis. However, the exact role of LL202 in inflammation along with its mechanism has not been explored. In this study, we investigated the anti-inflammatory effect of LL202 on intestinal inflammation by establishing dextran sulfate sodium (DSS)-induced experimental colitis. LL202 attenuated DSS-induced body weight loss, colon length shortening and colonic pathological damage. The inflammatory cells infiltration, myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities were decreased by LL202 in a dose-dependent manner. LL202 reduced the production of pro-inflammatory cytokines in serum and colon of DSS-induced mice as well. Mechanically, LL202 could decrease the expression and nuclear translation of AP-1 to protect against DSS-induced colitis. In lipopolysaccharide (LPS)-induced THP-1 cells, LL202 markedly decreased the secretion, mRNA level and protein expression of IL-1β, IL-6 and TNF-α via inhibiting ERK/JNK/p38 MAPK pathways and the nuclear translocation of AP-1. Furthermore, these findings were confirmed in LPS-induced bone marrow derived macrophages (BMDM). In conclusion, our study demonstrated that LL202 could exert its anti-inflammatory effect via inhibiting MAPK/AP-1 signaling, which suggested that LL202 might be a potential effective drug for the treatment of inflammatory bowel diseases. PMID:27590510

  9. Downregulation of mitogen-activated protein kinase 1 of Leishmania donovani field isolates is associated with antimony resistance.

    PubMed

    Ashutosh; Garg, Mansi; Sundar, Shyam; Duncan, Robert; Nakhasi, Hira L; Goyal, Neena

    2012-01-01

    Emergence of resistance to pentavalent antimonials has become a severe obstacle in the treatment of visceral leishmaniasis (VL) on the Indian subcontinent. The mechanisms operating in laboratory-generated strains are somewhat known, but the determinants of clinical antimony resistance are not well understood. By utilizing a DNA microarray expression profiling approach, we identified a gene encoding mitogen-activated protein kinase 1 (MAPK1) for the kinetoplast protozoan Leishmania donovani (LdMAPK1) that was consistently downregulated in antimony-resistant field isolates. The expression level of the gene was validated by real-time PCR. Furthermore, decreased expression of LdMAPK1 was also confirmed at the protein level in resistant isolates. Primary structure analysis of LdMAPK1 revealed the presence of all of the characteristic features of MAPK1. When expressed in Escherichia coli, the recombinant enzyme showed kinase activity with myelin basic protein as the substrate and was inhibited by staurosporine. Interestingly, overexpression of this gene in a drug-sensitive laboratory strain and a resistant field isolate resulted in increased the sensitivity of the transfectants to potassium antimony tartrate, suggesting that it has a role in antimony resistance. Our results demonstrate that downregulation of LdMAPK1 may be in part correlated with antimony drug resistance in Indian VL isolates.

  10. Inhibition of cultured bovine aortic endothelial cell proliferation by sodium spirulan, a new sulfated polysaccharide isolated from Spirulina platensis.

    PubMed

    Kaji, Toshiyuki; Fujiwara, Yasuyuki; Hamada, Chieko; Yamamoto, Chika; Shimada, Satomi; Lee, Jung-Bum; Hayashi, Toshimitsu

    2002-06-01

    Sodium spirulan (Na-SP) is a sulfated polysaccharide isolated from the blue-green alga Spirulina platensis, which consists of two types of disaccharide repeating units, O-hexuronosyl-rhamnose (aldobiuronic acid) and O-rhamnosyl-3-O-methylrhamnose (acofriose) with sulfate groups, other minor saccharides and sodium ion. Vascular endothelial cells are present on the inner surface of blood vessels in a monolayer and have anticoagulant properties. To address the question whether Na-SP influences the maintenance of endothelial cell monolayers, we investigated the proliferation of cultured bovine aortic endothelial cells treated with Na-SP. It was found that Na-SP has an inhibitory activity on endothelial cell proliferation accompanied with suppression of whole protein synthesis but without non-specific cell damage. The inhibitory activity of Na-SP was the strongest when compared to that of heparan sulfate, heparin, dextran sulfate, dermatan sulfate, chondroitin sulfate A/C and hyaluronan. Furthermore, it was shown that the inhibitory activity of Na-SP disappeared by either desulfation or depolymerization. The present data suggest that Na-SP is a unique sulfated polysaccharide that strongly inhibits vascular endothelial cell proliferation, and the inhibitory activity requires polymerization of sulfated O-rhamnosyl-acofriose repeating units.

  11. Inhibition of antibacterial activity of himastatin, a new antitumor antibiotic from Streptomyces hygroscopicus, by fatty acid sodium salts.

    PubMed Central

    Mamber, S W; Brookshire, K W; Dean, B J; Firestone, R A; Leet, J E; Matson, J A; Forenza, S

    1994-01-01

    Himastatin, a cyclohexadepsipeptide antibiotic, had in vivo antitumor activity against localized P388 leukemia and B16 melanoma but had no distal site antitumor activity. An in vitro Bacillus subtilis well-agar diffusion assay was employed to test the hypothesis that himastatin was enzymatically inactivated. The activity of himastatin against B. subtilis was inhibited when himastatin was mixed with mouse liver S9 fraction and microsomes. However, subsequent investigations demonstrated that the markedly decreased antibacterial activity was not enzymatic in nature but was related to the presence of certain fatty acid salts. Saturated fatty acid sodium salts with a carbon chain number of 8 or more reduced the antimicrobial activity of himastatin 50 to 100 times. If antibiotics such as ampicillin, bacitracin, chloramphenicol, and tunicamycin were used in place of himastatin, no meaningful reduction in antibacterial activity occurred. However, the antibacterial activity of the membrane-active peptide antibiotic polymyxin B, but not that of polymyxin E (colistin), was reduced in a manner similar to that of himastatin. Importantly, the activity of himastatin against HCT-116 colon adenocarcinoma cells in soft agar was markedly reduced in the presence of sodium palmitate as the reference fatty acid salt. The data indicate that himastatin may be trapped in micelles in vitro. It may be speculated that the lack of distal site antitumor activity resulted from similar complex formation between himastatin and lipids in vivo. The results also suggest that the cancer cytotoxic and antimicrobial effects of himastatin may result from interactions with the cell membrane. PMID:7872760

  12. CP-MLR/PLS directed QSAR study on apical sodium-codependent bile acid transporter inhibition activity of benzothiepines.

    PubMed

    Sharma, Brij Kishore; Singh, Prithvi; Pilania, Pradeep; Sarbhai, Kirti; Prabhakar, Yenamandra S

    2011-02-01

    The apical sodium-codependent bile acid transporter (ASBT) inhibition activity of benzothiepine derivatives have been analyzed based on topological and molecular features. Analysis of the structural features in conjunction with the biological endpoints in Combinatorial Protocol in Multiple Linear Regression (CP-MLR) led to the identification of 21 descriptors for modeling the activity. The study clearly suggested that the role of Randic shape index (path/walk ratio 3) and topological charges of 2-, 5-, and 6-orders to optimize the ASBT inhibitory activity of titled compounds. The influence of atomic van der Waals volumes, masses, Sanderson electronegativities, and polarizabilities are indicated via different lags of Moran and Geary autocorrelations. Presence of tertiary aromatic amine functionality in molecular structure has also shown its relevance in rationalizing the biological actions of benzothiepines. The PLS analysis has confirmed the dominance of information content of CP-MLR identified descriptors for modeling the activity when compared to those of the leftover ones.

  13. Conotoxins That Could Provide Analgesia through Voltage Gated Sodium Channel Inhibition

    PubMed Central

    Munasinghe, Nehan R.; Christie, MacDonald J.

    2015-01-01

    Chronic pain creates a large socio-economic burden around the world. It is physically and mentally debilitating, and many sufferers are unresponsive to current therapeutics. Many drugs that provide pain relief have adverse side effects and addiction liabilities. Therefore, a great need has risen for alternative treatment strategies. One rich source of potential analgesic compounds that has emerged over the past few decades are conotoxins. These toxins are extremely diverse and display selective activity at ion channels. Voltage gated sodium (NaV) channels are one such group of ion channels that play a significant role in multiple pain pathways. This review will explore the literature around conotoxins that bind NaV channels and determine their analgesic potential. PMID:26690478

  14. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  15. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  16. 40 CFR 721.1930 - Butanoic acid, antimony (3=) salt.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Butanoic acid, antimony (3=) salt. 721... Substances § 721.1930 Butanoic acid, antimony (3=) salt. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as butanoic acid, antimony (3=) salt (PMN...

  17. Inhibition of carbachol-evoked oscillatory currents by the NO donor sodium nitroprusside in guinea-pig ileal myocytes.

    PubMed

    Chung, Seung-Soo; Ahn, Duck-Sun; Lee, Hong-Ghi; Lee, Young-Ho; Nam, Taick-Sang

    2005-07-01

    The effect of sodium nitroprusside (SNP) on carbachol (CCh)-evoked inward cationic current (Icat) oscillations in guinea-pig ileal longitudinal myocytes was investigated using the whole-cell patch-clamp technique and permeabilized longitudinal muscle strips. SNP (10 microm) completely inhibited I(cat) oscillations evoked by 1 microm CCh. 1H-(1,2,4) Oxadiazole [4,3-a] quinoxaline-1-one (ODQ; 1 microm) almost completely prevented the inhibitory effect of SNP on Icat oscillations. 8-Bromo-guanosine 3',5'-cyclic monophosphate (8-Br-cGMP; 30 microm) in the pipette solution completely abolished Icat oscillations. However, a pipette solution containing Rp-8-Br-cGMP (30 microm) almost completely abolished the inhibitory effect of SNP on Icat oscillations. When the intracellular calcium concentration ([Ca2+]i) was held at a resting level using BAPTA (10 mm) and Ca2+ (4.6 microm) in the pipette solution, CCh (1 microm) evoked only the sustained component of Icat without any oscillations and SNP did not affect the current. A high concentration of inositol 1,4,5-trisphosphate (IP3; 30 microm) in the patch pipette solutions significantly reduced the inhibitory effect of SNP (10 microm) on Icat oscillations. SNP significantly inhibited the Ca2+ release evoked by either CCh or IP3 but not by caffeine in permeabilized preparations of longitudinal muscle strips. These results suggest that the inhibitory effects of SNP on Icat oscillations are mediated, in part, by functional modulation of the IP3 receptor, and not by the inhibition of cationic channels themselves or by muscarinic receptors in the plasma membrane. This inhibition seems to be mediated by an increased cGMP concentration in a protein kinase G-dependent manner.

  18. Neutrophils influx and proinflammatory cytokines inhibition by sodium salicylate, unlike aspirin, in Candida albicans-induced peritonitis model.

    PubMed

    Pereira, Priscilla Aparecida Tártari; Bini, Daniel; Bovo, Fernanda; Faccioli, Lucia Helena; Monteiro, Marta Chagas

    2016-07-01

    Sodium salicylate (NaS) and aspirin (ASA) are known to have a variety of effects on microorganisms, such as fungus (C. albicans and C. neoformans), moreover, it have effects in leukocyte adhesion and migration in vitro. In this report, we investigated the effect of ASA and NaS in neutrophil migration and cytokine production in C. albicans-induced peritonitis murine model. For this, mice were treated intraperitoneally (i.p) or orally (po) with NaS or ASA; after they were stimulated i.p. with C. albicans, the cellular migration was evaluated 24 h after stimulation. NaS, in mice treated i.p., unlike ASA, was able to inhibit the neutrophil migration and proinflammatory cytokine production induced by C. albicans, such as TNF-α, IL-1, IFN-γ, IL-12, and IL-10, but did not alter the IL-4 levels in these animals. However, the po treatment with same the dose of NaS or ASA did not affect the influx of this cell for inflammatory site. These results suggest that the NaS inhibits cellular migration and proinflammatory cytokine by different anti-inflammatory mechanism compared to ASA.

  19. Development of a screening approach to detect thyroid disrupting chemicals that inhibit the human sodium iodide symporter (NIS).

    PubMed

    Hallinger, Daniel R; Murr, Ashley S; Buckalew, Angela R; Simmons, Steven O; Stoker, Tammy E; Laws, Susan C

    2017-04-01

    The U.S. EPA's Endocrine Disruptor Screening Program aims to use high-throughput assays and computational toxicology models to screen and prioritize chemicals that may disrupt the thyroid signaling pathway. Thyroid hormone biosynthesis requires active iodide uptake mediated by the sodium/iodide symporter (NIS). Monovalent anions, such as the environmental contaminant perchlorate, are competitive inhibitors of NIS, yet limited information exists for more structurally diverse chemicals. A novel cell line expressing human NIS, hNIS-HEK293T-EPA, was used in a radioactive iodide uptake (RAIU) assay to identify inhibitors of NIS-mediated iodide uptake. The RAIU assay was optimized and performance evaluated with 12 reference chemicals comprising known NIS inhibitors and inactive compounds. An additional 39 chemicals including environmental contaminants were evaluated, with 28 inhibiting RAIU over 20% of that observed for solvent controls. Cell viability assays were performed to assess any confounding effects of cytotoxicity. RAIU and cytotoxic responses were used to calculate selectivity scores to group chemicals based on their potential to affect NIS. RAIU IC50 values were also determined for chemicals that displayed concentration-dependent inhibition of RAIU (≥50%) without cytotoxicity. Strong assay performance and highly reproducible results support the utilization of this approach to screen large chemical libraries for inhibitors of NIS-mediated iodide uptake.

  20. Synergistic effects between sodium tripolyphosphate and zinc sulfate in corrosion inhibition for copper in neutral tap water

    SciTech Connect

    Feng, Y.; Siow, K.S.; Teo, W.K.; Tan, K.L.; Hsieh, A.K.

    1997-07-01

    The corrosion inhibition behavior of sodium tripolyphosphate (Na{sub 5}P{sub 3}O{sub 10}, or TPP) and zinc sulfate and the synergistic effects between them were studied for copper in neutral simulated tap water using electrochemical methods, x-ray photoelectron spectroscopy, and scanning electron microscopy. Zn{sup 2+} alone showed few inhibiting effects on copper corrosion. The film formed in the presence of Zn{sup 2+} was porous and composed mainly of cuprous oxide, which was similar in morphology and composition to films formed in the absence of the inhibitor. In the presence of TPP, a smooth and compact film, believed to be of Cu(II)-TPP compounds, formed on the copper surface. More protective films were formed in solutions containing TPP and Zn{sup 2+} as a blend. High zinc content (15% to 19%) was detected by XPS. Synergistic effects of TPP and Zn{sup 2+} were believed to result from formation of Zn(II)-TPP compounds that incorporated in the films, with Cu(II)-TPP in the upper layer and Cu{sub 2}O in the inner layer. The zinc compounds increased the anodic diffusion resistance of copper ions in the films and enhanced polarization of the cathodic reduction of dissolved oxygen.

  1. Sodium orthovanadate inhibits growth of human hepatocellular carcinoma cells in vitro and in an orthotopic model in vivo.

    PubMed

    Wu, Yaohua; Ma, Yong; Xu, Zhilin; Wang, Dawei; Zhao, Baolei; Pan, Huayang; Wang, Jizhou; Xu, Dongsheng; Zhao, Xiaoyang; Pan, Shangha; Liu, Lianxin; Dai, Wenjie; Jiang, Hongchi

    2014-08-28

    The transition metal vanadium is widely distributed in the environment and exhibits various biological and physiological effects in the human body. As a well known vanadium compound, sodium orthovanadate (SOV) has shown promising antineoplastic activity in several human cancers. However, the effects of SOV on liver cancer are still unknown. In this study, for the first time, we showed that SOV could effectively suppress proliferation, induce G2/M cell cycle arrest and apoptosis, and diminish the mitochondrial membrane potential (MMP) of HCC cells in vitro. In addition, our in vitro results were recapitulated in vivo, showing that SOV exhibited a dose-dependent inhibition of growth of human HCC in an orthotopic model, evidenced by the reduction in tumor size, proliferation index and microvessel density, and increase in cell apoptosis. Most important, we found that SOV could inhibit autophagy in HCC cells in vitro and in vivo, which plays a prodeath role. Thus, our findings suggest that SOV could effectively suppress the growth of human HCC through the regulations of proliferation, cell cycle, apoptosis and autophagy, and thus may act as a potential therapeutic agent in HCC treatment.

  2. Andrographolide Sodium Bisulfate Prevents UV-Induced Skin Photoaging through Inhibiting Oxidative Stress and Inflammation

    PubMed Central

    Zhan, Janis Ya-Xian; Wang, Xiu-Fen; Liu, Yu-Hong; Zhang, Zhen-Biao; Wang, Lan; Chen, Jian-Nan; Huang, Song; Zeng, Hui-Fang; Lai, Xiao-Ping

    2016-01-01

    Andrographolide sodium bisulfate (ASB), a water-soluble form made from andrographolide through sulfonating reaction, is an antioxidant and anti-inflammatory drug; however, the antiphotoaging effect of ASB has still not been revealed. Oxidative stress and inflammation are known to be responsible for ultraviolet (UV) irradiation induced skin damage and consequently premature aging. In this study, we aimed at examining the effect of ASB on UV-induced skin photoaging of mice by physiological and histological analysis of skin and examination of skin antioxidant enzymes and immunity analyses. Results showed that topical administration of ASB suppressed the UV-induced skin thickness, elasticity, wrinkles, and water content, while ASB, especially at dose of 3.6 mg/mouse, increased the skin collagen content by about 53.17%, decreased the epidermal thickness by about 41.38%, and prevented the UV-induced disruption of collagen fibers and elastic fibers. Furthermore, ASB decreased MDA level by about 40.21% and upregulated the activities of SOD and CAT and downregulated the production of IL-1β, IL-6, IL-10, and TNF-α in UV-irradiated mice. Our study confirmed the protective effect of ASB against UV-induced photoaging and initially indicated that this effect can be attributed to its antioxidant and anti-inflammatory activities in vivo, suggesting that ASB may be a potential antiphotoaging agent. PMID:26903706

  3. Inhibition effects on fermentation of hardwood extracted hemicelluloses by acetic acid and sodium.

    PubMed

    Walton, Sara; van Heiningen, Adriaan; van Walsum, Peter

    2010-03-01

    Extraction of hemicellulose from hardwood chips prior to pulping is a possible method for producing ethanol and acetic acid in an integrated forest bio-refinery, adding value to wood components normally relegated to boiler fuel. Hemicellulose was extracted from hardwood chips using green liquor, a pulping liquor intermediate consisting of aqueous NaOH, Na(2)CO(3), and Na(2)S, at 160 degrees C, held for 110 min in a 20 L rocking digester. The extracted liquor contained 3.7% solids and had a pH of 5.6. The organic content of the extracts was mainly xylo-oligosaccharides and acetic acid. Because it was dilute, the hemicellulose extract was concentrated by evaporation in a thin film evaporator. Concentrates from the evaporator reached levels of up to 10% solids. Inhibitors such as acetic acid and sodium were also concentrated by this method, presenting a challenge for the fermentation organisms. Fermentation experiments were conducted with Escherichia coli K011. The un-concentrated extract supported approximately 70% conversion of the initial sugars in 14 h. An extract evaporated down to 6% solids was also fermentable while a 10% solids extract was not initially fermentable. Strain conditioning was later found to enable fermentation at this level of concentration. Alternative processing schemes or inhibitor removal prior to fermentation are necessary to produce ethanol economically.

  4. Sodium-glucose cotransporter inhibition: therapeutic potential for the treatment of type 2 diabetes mellitus.

    PubMed

    Raskin, Philip

    2013-07-01

    Results from randomized controlled trials have demonstrated that the risk of microvascular complications can be reduced by intensive glycaemic control in patients with type 2 diabetes mellitus (T2DM). However, only about half of patients with diagnosed diabetes achieve recommended glycaemic goals. New therapies with complementary mechanisms of action that are independent of insulin secretion or action may provide additional therapeutic options to enable patients to achieve glycaemic control. The kidney plays an important role in glucose homeostasis, primarily by the reabsorption of filtered glucose. The sodium-glucose cotransporter 2 (SGLT2), located in the proximal convoluted tubule, is responsible for the majority of glucose reabsorption by the kidney. SGLT2 inhibitors offer a novel approach to treat T2DM and reduce hyperglycaemia by increasing urinary excretion of glucose. Dapagliflozin, an SGLT2 inhibitor recently approved in Europe for the treatment of T2DM, improves glycaemic control in patients with T2DM when used as monotherapy or when added to other diabetes medications, such as metformin, sulfonylureas, pioglitazone, and insulin. As a class, SGLT2 inhibitors are well tolerated and have a low propensity to cause hypoglycaemia. An increase in signs, symptoms, and other events suggestive of genital and, in some studies, urinary tract infections has been reported with SGLT2 inhibitors. Results from ongoing and future clinical trials will help define the role for this new class of investigational compounds, with its unique mechanism of action, as a treatment option for reducing hyperglycaemia in patients with T2DM.

  5. Speciation of antimony(III) and antimony(V) by electrothermal atomic absorption spectrometry after ultrasound-assisted emulsification of solidified floating organic drop microextraction.

    PubMed

    Wen, Shengping; Zhu, Xiashi

    2013-10-15

    A simple, sensitive and efficient method of ultrasound-assisted emulsification of solidified floating organic drop microextraction (USE-SFODME) coupled to electrothermal atomic absorption spectrometry for the speciation of antimony at different oxidation state Sb(III)/Sb(V) in environmental samples was established. In this method, the hydrophobic complex of Sb(III) with sodium diethyldithiocarbamate (DDTC) is extracted by 1-undecanol at pH 9.0, while Sb(V) remains in aqueous phase. Sb(V) content can be calculated by subtracting Sb(III) from the total antimony after reducing Sb(V) to Sb(III) by l-cysteine. Various factors affecting USE-SFODME including pH, extraction solvent and its volume, concentration of DDTC, sonication time, and extraction temperature were investigated. Under the optimized conditions, the calibration curve was linear in the range from 0.05 to 10.0 ng mL(-1), with the limit of detection (3σ) 9.89 ng L(-1) for Sb(III). The relative standard deviation for Sb(III) was 4.5% (n=9, c=1.0 ng mL(-1)). This method was validated against the certified reference materials (GSB 07-1376-2001, GBW07441), and applied to the speciation of antimony in environmental samples (soil and water samples) with satisfactory results.

  6. Comparison of sodium acid sulfate to citric acid to inhibit browning of fresh-cut potatoes.

    PubMed

    Calder, Beth L; Kash, Emily A; Davis-Dentici, Katherine; Bushway, Alfred A

    2011-04-01

    Sodium acid sulfate (SAS) dip treatments were evaluated against a distilled water control and citric acid (CA) to compare its effectiveness in reducing enzymatic browning of raw, French-fry cut potatoes. Two separate studies were conducted with dip concentrations ranging from 0%, 1%, and 3% in experiment 1 to 0%, 2%, and 2.5% in experiment 2 to determine optimal dip concentrations. Russet Burbank potatoes were peeled, sliced, and dipped for 1 min and stored at 3 °C. Color, texture, fry surface pH, and microbiological analyses were conducted on days 0, 7, and 14. The 3% SAS- and CA-treated samples had significantly (p<0.0001) lower pH levels on fry surfaces than all other treatments. Both acidulants had significantly (p≤0.05) lower aerobic plate counts compared to controls in both studies by day 7. However, SAS appeared to be the most effective at the 3% level in maintaining a light fry color up to day 14 and had the highest L-values than all other treatments. The 3% SAS-treated fry slices appeared to have the least change in textural properties over storage time, having a significantly (p=0.0002) higher force value (kg force [kgf]) than the other treatments during experiment 1, without any signs of case-hardening that appeared in the control and CA-treated samples. SAS was just as comparable to CA in reducing surface fry pH and also lowering microbial counts over storage time. According to the results, SAS may be another viable acidulant to be utilized in the fresh-cut fruit and vegetable industry.

  7. Sodium alginate oligosaccharides from brown algae inhibit Salmonella Enteritidis colonization in broiler chickens.

    PubMed

    Yan, G L; Guo, Y M; Yuan, J M; Liu, D; Zhang, B K

    2011-07-01

    The effects of sodium alginate oligosaccharides (sAO) on growth performance, cecal microbiota, Salmonella translocation to internal organs, and mucosal immune responses to challenge with Salmonella enterica serovar Enteritidis in broiler chickens were investigated. We designed an experiment with a 2 × 3 factorial arrangement, in which 3 feed treatments with supplementation of sAO at 0 (controls), 0.04, or 0.2% were provided in the diet for birds not challenged or challenged with Salmonella Enteritidis. There were 5 randomly placed replicate pens for each treatment. At 8 to 12 d of age, one-half the poults were orally gavaged with 10(8) cfu of Salmonella Enteritidis and the nonchallenged groups were inoculated with sterile PBS. Body weight loss and mortality resulting from Salmonella infection were mitigated by the addition of sAO. Supplementation of sAO at 0.2% was the most effective concentration for reducing Salmonella colonization and increasing the number of lactic acid bacteria in the cecum of chickens challenged with Salmonella Enteritidis. Cecal Salmonella Enteritidis-specific IgA production was significantly increased by sAO at 0.2% at 5 d postchallenge compared with the other treatments and was maintained at higher levels at the 2 dosages of sAO at 10 d postchallenge. With Salmonella Enteritidis challenge, sAO at 0.04% showed an anti-inflammatory effect through upregulation of interleukin (IL)-10 expression in the cecal tonsils. The supplementation level of 0.2% showed dramatic immunostimulatory activity by inducing interferon-γ, IL-10, and IL-1β mRNA expression in cecal tonsils of nonchallenged birds. However, the high level of sAO induced a robust mucosal immune response in the absence of a challenge, and this may have led to a decline in BW. These findings suggest that dietary sAO can decrease Salmonella colonization and improve intestinal barrier function and performance of chickens.

  8. Antimony sulfide thin films prepared by laser assisted chemical bath deposition

    NASA Astrophysics Data System (ADS)

    Shaji, S.; Garcia, L. V.; Loredo, S. L.; Krishnan, B.; Aguilar Martinez, J. A.; Das Roy, T. K.; Avellaneda, D. A.

    2017-01-01

    Antimony sulfide (Sb2S3) thin films were prepared by laser assisted chemical bath deposition (LACBD) technique. These thin films were deposited on glass substrates from a chemical bath containing antimony chloride, acetone and sodium thiosulfate under various conditions of normal chemical bath deposition (CBD) as well as in-situ irradiation of the chemical bath using a continuous laser of 532 nm wavelength. Structure, composition, morphology, optical and electrical properties of the Sb2S3 thin films produced by normal CBD and LACBD were analyzed by X-Ray diffraction (XRD), Raman Spectroscopy, Atomic force microscopy (AFM), X-Ray photoelectron spectroscopy (XPS), UV-vis spectroscopy and Photoconductivity. The results showed that LACBD is an effective synthesis technique to obtain Sb2S3 thin films for optoelectronic applications.

  9. Microbial antimony biogeochemistry: Enzymes, regulation, and related metabolic pathways

    USGS Publications Warehouse

    Li, Jingxin; Qian Wang,; Oremland, Ronald S.; Kulp, Thomas R.; Rensing, Christopher; Wang, Gejiao

    2016-01-01

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of “antimonotrophs.”

  10. Microbial Antimony Biogeochemistry: Enzymes, Regulation, and Related Metabolic Pathways

    PubMed Central

    Li, Jingxin; Wang, Qian; Oremland, Ronald S.; Kulp, Thomas R.; Rensing, Christopher

    2016-01-01

    Antimony (Sb) is a toxic metalloid that occurs widely at trace concentrations in soil, aquatic systems, and the atmosphere. Nowadays, with the development of its new industrial applications and the corresponding expansion of antimony mining activities, the phenomenon of antimony pollution has become an increasingly serious concern. In recent years, research interest in Sb has been growing and reflects a fundamental scientific concern regarding Sb in the environment. In this review, we summarize the recent research on bacterial antimony transformations, especially those regarding antimony uptake, efflux, antimonite oxidation, and antimonate reduction. We conclude that our current understanding of antimony biochemistry and biogeochemistry is roughly equivalent to where that of arsenic was some 20 years ago. This portends the possibility of future discoveries with regard to the ability of microorganisms to conserve energy for their growth from antimony redox reactions and the isolation of new species of “antimonotrophs.” PMID:27342551

  11. Sodium glucose transporter 2 (SGLT2) inhibition with empagliflozin improves cardiac diastolic function in a female rodent model of diabetes.

    PubMed

    Habibi, Javad; Aroor, Annayya R; Sowers, James R; Jia, Guanghong; Hayden, Melvin R; Garro, Mona; Barron, Brady; Mayoux, Eric; Rector, R Scott; Whaley-Connell, Adam; DeMarco, Vincent G

    2017-01-13

    Obese and diabetic individuals are at increased risk for impairments in diastolic relaxation and heart failure with preserved ejection fraction. The impairments in diastolic relaxation are especially pronounced in obese and diabetic women and predict future cardiovascular disease (CVD) events in this population. Recent clinical data suggest sodium glucose transporter-2 (SGLT2) inhibition reduces CVD events in diabetic individuals, but the mechanisms of this CVD protection are unknown. To determine whether targeting SGLT2 improves diastolic relaxation, we utilized empagliflozin (EMPA) in female db/db mice. Eleven week old female db/db mice were fed normal mouse chow, with or without EMPA, for 5 weeks. Blood pressure (BP), HbA1c and fasting glucose were significantly increased in untreated db/db mice (DbC) (P < 0.01). EMPA treatment (DbE) improved glycemic indices (P < 0.05), but not BP (P > 0.05). At baseline, DbC and DbE had already established impaired diastolic relaxation as indicated by impaired septal wall motion (>tissue Doppler derived E'/A' ratio) and increased left ventricular (LV) filling pressure (sodium channel (ENaC), and the development of these abnormalities were reduced with EMPA. DbC exhibited eccentric LV hypertrophy that was slightly improved by EMPA, indicated by a reduction in cardiomyocyte cross sectional area. In summary, EMPA improved glycemic indices along with diastolic relaxation, as well as SGK1/ENaC profibrosis signaling and associated interstitial fibrosis, all of which occurred in the absence of any changes in BP.

  12. Sulfonylurea receptors inhibit the epithelial sodium channel (ENaC) by reducing surface expression.

    PubMed

    Konstas, A A; Bielfeld-Ackermann, A; Korbmacher, C

    2001-08-01

    In the kidney the epithelial Na+ channel (ENaC) is co-expressed with the sulfonylurea receptor (SUR), an ABC protein that shares a high degree of homology with the cystic fibrosis transmembrane conductance regulator (CFTR) and reportedly modifies ENaC in various preparations. To investigate a possible regulatory relationship between SUR and ENaC, we performed co-expression studies on Xenopus laevis oocytes, which were assayed for amiloride-sensitive currents (DeltaIami). Moreover, a chemiluminescence assay was used to investigate the surface expression of extracellular hemagglutinin-tagged SUR1 (SUR1-HA) or HA-tagged ENaC (ENaC-HA). In oocytes co-injected with SUR1/ENaC (or SUR2B/ENaC) DeltaIami was reduced by congruent with 53% (or congruent with 45%) compared to DeltaIami measured in matched control oocytes injected with ENaC alone. The inhibitory effect of SUR on DeltaIami was preserved in oocytes expressing ENaC with C-terminally truncated subunits. Co-expression of SURs did not confer sensitivity of DeltaIami to diazoxide, pinacidil, tolbutamide, or glibenclamide. ENaC does not facilitate the surface expression of SUR1-HA, which is known to be retained in the endoplasmatic reticulum (ER) by an ER-retention/retrieval signal. SUR1-HAAAA, a mutant that lacks this signal, still inhibits ENaC currents. Chemiluminescence was reduced by congruent with 49% in oocytes co-expressing ENaC-HA/SUR1 compared to that in control oocytes expressing ENaC-HA alone. We conclude that SUR does not interact with ENaC at the level of the plasma membrane but that it inhibits DeltaIami by reducing surface expression of the channel.

  13. Keratinocyte Growth Factor Combined with a Sodium Hyaluronate Gel Inhibits Postoperative Intra-Abdominal Adhesions

    PubMed Central

    Wei, Guangbing; Zhou, Cancan; Wang, Guanghui; Fan, Lin; Wang, Kang; Li, Xuqi

    2016-01-01

    Postoperative intra-abdominal adhesion is a very common complication after abdominal surgery. One clinical problem that remains to be solved is to identify an ideal strategy to prevent abdominal adhesions. Keratinocyte growth factor (KGF) has been proven to improve the proliferation of mesothelial cells, which may enhance fibrinolytic activity to suppress postoperative adhesions. This study investigated whether the combined administration of KGF and a sodium hyaluronate (HA) gel can prevent intra-abdominal adhesions by improving the orderly repair of the peritoneal mesothelial cells. The possible prevention mechanism was also explored. The cecum wall and its opposite parietal peritoneum were abraded after laparotomy to induce intra-abdominal adhesion formation. Animals were randomly allocated to receive topical application of HA, KGF, KGF + HA, or normal saline (Control). On postoperative day 7, the adhesion score was assessed with a visual scoring system. Masson’s trichrome staining, picrosirius red staining and hydroxyproline assays were used to assess the magnitude of adhesion and tissue fibrosis. Cytokeratin, a marker of the mesothelial cells, was detected by immunohistochemistry. The levels of tissue plasminogen activator (tPA), interleukin-6 (IL-6), and transforming growth factor β1 (TGF-β1) in the abdominal fluid were determined using enzyme-linked immunosorbent assays (ELISAs). Western blotting was performed to examine the expression of the TGF-β1, fibrinogen and α-smooth muscle actin (α-SMA) proteins in the rat peritoneal adhesion tissue. The combined administration of KGF and HA significantly reduced intra-abdominal adhesion formation and fibrin deposition and improved the orderly repair of the peritoneal mesothelial cells in the rat model. Furthermore, the combined administration of KGF and HA significantly increased the tPA levels but reduced the levels of IL-6, tumor necrosis factor α (TNF-α) and TGF-β1 in the abdominal fluid. The expression

  14. Soluble Epoxide Hydrolase Deficiency Inhibits Dextran Sulfate Sodium-induced Colitis and Carcinogenesis in Mice

    PubMed Central

    DONG, HUA; LIAO, JIE; HAMMOCK, BRUCE D.; YANG, GUANG-YU

    2014-01-01

    Soluble epoxide hydrolase (sEH) hydrolyses/inactivates anti-inflammatory epoxyeicosatrienoic acids (EETs) to their corresponding diols, and targeting sEH leads to strong anti-inflammatory effects. In the present study, using a tissue microarray and immunohistochemical approach, a significant increase of sEH expression was identified in ulcerative colitis (UC)-associated dysplasia and adenocarcinoma. The effects of deficiency in the sEH gene were determined on dextran sulfate sodium (DSS) colitis-induced carcinogenesis. The effects of EETs on lipopolysaccharide (LPS)-activated macrophages were analyzed in vitro. With extensive histopathological and immunohistochemical analyses, compared to wild-type mice, sEH−/− mice exhibited a significant decrease in tumor incidence (13/20 vs. 6/19, p<0.05) and a markedly reduced average tumor size (59.62±20.91 mm3 vs. 22.42±11.22 mm3), and a significant number of pre-cancerous dysplasia (3±1.18 vs. 2±0.83, p<0.01). The inflammatory activity, as measured by the extent/proportion of erosion/ulceration/dense lymphoplasmacytosis (called active colitis index) in the colon, was significantly lower in sEH−/− mice (44.7%±24.9% vs. 20.2%±16.2%, p<0.01). The quantitative polymerase chain reaction (qPCR) assays demonstrated significantly low levels of cytokines/chemokines including monocyte chemoattractant protein (MCP-1), inducible nitric oxide synthase (iNOS), vasopressin-activated calcium-mobilizing (VCAM-1), interleukin-1 beta (IL-1β) and tumor necrosis factor-alpha (TNF-α). In vitro, LPS-activated macrophages treated with 14,15-EET showed a significant reduction of LPS-triggered IL-1β and TNF-α expression. Eicosanoic acid metabolic profiling revealed a significant increase of the ratios of EETs/dihydroeicosatrienoic acids (DHETs) and epoxyoctadecennoic acid/dihydroxyoctadecenoic acid (EpOMEs/DiHOMEs). These results indicate that sEH plays an important role in the development of colitis and in inducing carcinogenesis

  15. Imipramine exploits histone deacetylase 11 to increase the IL-12/IL-10 ratio in macrophages infected with antimony-resistant Leishmania donovani and clears organ parasites in experimental infection.

    PubMed

    Mukherjee, Sandip; Mukherjee, Budhaditya; Mukhopadhyay, Rupkatha; Naskar, Kshudiram; Sundar, Shyam; Dujardin, Jean-Claude; Roy, Syamal

    2014-10-15

    The efflux of antimony through multidrug resistance protein (MDR)-1 is the key factor in the failure of metalloid treatment in kala-azar patients infected with antimony-resistant Leishmania donovani (Sb(R)LD). Previously we showed that MDR-1 upregulation in Sb(R)LD infection is IL-10-dependent. Imipramine, a drug in use for the treatment of depression and nocturnal enuresis in children, inhibits IL-10 production from Sb(R)LD-infected macrophages (Sb(R)LD-Mϕs) and favors accumulation of surrogates of antimonials. It inhibits IL-10-driven nuclear translocation of c-Fos/c-Jun, critical for enhanced MDR-1 expression. The drug upregulates histone deacetylase 11, which inhibits acetylation of IL-10 promoter, leading to a decrease in IL-10 production from Sb(R)LD-Mϕs. It abrogates Sb(R)LD-mediated p50/c-Rel binding to IL-10 promoter and preferentially recruits p65/RelB to IL-12 p35 and p40 promoters, causing a decrease in IL-10 and overproduction of IL-12 in Sb(R)LD-Mϕs. Histone deacetylase 11 per se does not influence IL-12 promoter activity. Instead, a imipramine-mediated decreased IL-10 level allows optimal IL-12 production in Sb(R)LD-Mϕs. Furthermore, exogenous rIL-12 inhibits intracellular Sb(R)LD replication, which can be mimicked by the presence of Ab to IL-10. This observation indicated that reciprocity exists between IL-10 and IL-12 and that imipramine tips the balance toward an increased IL-12/IL-10 ratio in Sb(R)LD-Mϕs. Oral treatment of infected BALB/c mice with imipramine in combination with sodium stibogluconate cleared organ Sb(R)LD parasites and caused an expansion of the antileishmanial T cell repertoire where sodium stibogluconate alone had no effect. Our study deciphers a detailed molecular mechanism of imipramine-mediated regulation of IL-10/IL-12 reciprocity and its impact on Sb(R)LD clearance from infected hosts.

  16. The Diffusion of Antimony of Alpha Iron.

    DTIC Science & Technology

    Diffusion coefficients of antimony in alpha iron were determined in the temperature range 700 to 900C using the residual activity method. Specimens...negligible effect on the diffusion of antomony in alpha iron . These results are discussed in relation to the phenomenon of temper brittleness in steels

  17. Separation of Lead from Crude Antimony by Pyro-Refining Process with NaPO3 Addition

    NASA Astrophysics Data System (ADS)

    Ye, Longgang; Hu, Yuejie; Xia, Zhimei; Chen, Yongming

    2016-06-01

    The main purpose of this study was to separate lead from crude antimony through an oxidation pyro-refining process and by using sodium metaphosphate as a lead elimination reagent. The process parameters that will affect the refining results were optimized experimentally under controlled conditions, such as the sodium metaphosphate charging dosage, the refining temperature and duration, and the air flow rate, to determine their effect on the lead content in refined antimony and the lead removal rate. A minimum lead content of 0.0522 wt.% and a 98.6% lead removal rate were obtained under the following optimal conditions: W_{{{NaPO}_{{3}} }} = 15% W Sb (where W represents weight), a refining temperature of 800°C, a refining time of 30 min, and an air flow rate of 3 L/min. X-ray diffractometry and scanning electron microscopy showed that high-purity antimony was obtained. The smelting operation is free from smoke or ammonia pollution when using monobasic sodium phosphate or ammonium dihydrogen phosphate as the lead elimination reagent. However, this refining process can also remove a certain amount of sulfur, cobalt, and silicon simultaneously, and smelting results also suggest that sodium metaphosphate can be used as a potential lead elimination reagent for bismuth and copper refining.

  18. EP3 receptors inhibit antidiuretic-hormone-dependent sodium transport across frog skin epithelium.

    PubMed

    Rytved, K A; Nielsen, R

    1999-01-01

    We examined the effect of prostaglandin E2 (PGE2) on antidiuretic hormone (ADH)-dependent Na+ transport and cAMP production in isolated frog skin epithelium. ADH caused an increase in transepithelial Na+ transport and a decrease in cellular potential, indicating an increase in apical Na+ permeability. Subsequent addition of PGE2 decreased Na+ transport and repolarised the cells. The PGE2 receptor EP1/3-selective analogue sulprostone and the PGE2 receptor EP2/3-selective analogue misoprostol were able to mimic the effect of PGE2. ADH increased cellular cAMP levels, whereas PGE2, sulprostone and misoprostol were able to reduce the ADH-dependent cAMP production. Measurements of intracellular Ca2+ concentration ([Ca2+]i) revealed that it was unaffected by both PGE2 and sulprostone. The inhibitory effect of PGE2 on ADH-dependent Na+ transport was also observed in Ca2+-depleted epithelia. We conclude that ADH stimulates transepithelial Na+ transport by increasing cellular cAMP levels, whereas PGE2 inhibits ADH-dependent Na+ transport by activating EP3-type receptors, which decrease cellular cAMP levels. We have found no evidence that [Ca2+]i is involved in the regulation of ADH-dependent Na+ transport by PGE2.

  19. Inhibition of nitrite-induced toxicity in channel catfish by calcium chloride and sodium chloride

    USGS Publications Warehouse

    Tommasso J.R., Wright; Simco, B.A.; Davis, K.B.

    1980-01-01

    Environmental chloride has been shown to inhibit methemoglobin formation in fish, thereby offering a protective effect against nitrite toxicity. Channel catfish (Ictalurus punctatus) were simultaneously exposed to various environmental nitrite and chloride levels (as either CaCl2 or NaCl) in dechlorinated tap water (40 mg/L total hardness, 47 mg/L alkalinity, 4 mg/L chloride, pH = 6.9-7.1, and temperature 21-24°C). Methemoglobin levels in fish simultaneously exposed to 2.5 mg/L nitrite and up to 30 mg/L chloride as either CaCl2 or NaCl were similar but significantly lower than in unprotected fish. Exposure to 10 mg/L nitrite and 60 mg/L chloride resulted in methemoglobin levels similar to those of the controls; most unprotected fish died. Fish exposed to 10 mg/L nitrite had significantly lower methemoglobin levels when protected with 15.0 mg/L chloride as CaCl2 than with NaCl. Fish exposed to nitrite in the presence of 60 mg/L chloride (as either CaCl2 or NaCl) had similar 24-h LC50 values that were significantly elevated above those obtained in the absence of chloride. Calcium had little effect on tolerance to nitrite toxicity in channel catfish in contrast to its large effect reported in steelhead trout (Salmo gairdneri).

  20. Cromolyn sodium prophylaxis inhibits pulmonary proinflammatory cytokines in infants at high risk for bronchopulmonary dysplasia.

    PubMed

    Viscardi, R M; Hasday, J D; Gumpper, K F; Taciak, V; Campbell, A B; Palmer, T W

    1997-11-01

    An imbalance of proinflammatory cytokines such as TNF-alpha, IL-1 beta, and the neutrophil chemotactic factor IL-8 and inhibitors (e.g., soluble TNF receptors and IL-1ra) in the lung during the first week of life may contribute to prolonged pulmonary inflammation and fibrosis in bronchopulmonary dysplasia (BPD). Disodium cromoglycate (DSCG) has anti-inflammatory effects in asthma, a disease with many similarities with BPD. In a prospective, randomized, blinded study, we examined whether early DSCG therapy inhibits proinflammatory cytokines in infants at risk for BPD. Twenty-six infants who were identified as high risk (> or = 75% probability) for oxygen-dependency at 28 d by a 12-h predictive score and survived 48 h were randomized to nebulized DSCG 20 mg (n = 13) or 2 cc NS (control, n = 13) every 6 h from Day 3 to Day 28. Lung lavage was collected on Day 3 (pre-study) and Day 7 and analyzed for cell count and differential and TNF-alpha, sTNFR1, sTNFR2, IL-1 beta, IL-1ra, and IL-8 concentrations. The groups' pre-study lavage cytokine concentrations were similar, but TNF-alpha and IL-8 concentrations were 3.6- and 4.9-fold lower in the DSCG group on Day 7 compared with levels in the control group. Soluble TNF receptors were unaffected by DSCG. There was a trend towards lower IL-1 beta levels in DSCG-treated infants on Day 7, but IL-1ra levels were unaffected by DSCG therapy. Three control subjects, but no DSCG-treated infants, died during the study period (p = 0.07). There were no significant differences between survivors of the two groups for oxygen-dependency at 28 d (100% control subjects; 85% DSCG). These results suggest that nebulized DSCG may exert an anti-inflammatory effect in the lungs of infants < or = 1,000 g at risk for BPD.

  1. Blockade of voltage-gated sodium channels inhibits invasion of endocrine-resistant breast cancer cells.

    PubMed

    Mohammed, Fatima H; Khajah, Maitham A; Yang, Ming; Brackenbury, William J; Luqmani, Yunus A

    2016-01-01

    Voltage-gated Na+ channels (VGSCs) are membrane proteins which are normally expressed in excitable cells but have also been detected in cancer cells, where they are thought to be involved in malignancy progression. In this study we examined the ion current and expression profile of VGSC (Nav1.5) in estrogen receptor (ER)-positive (MCF-7) and silenced (pII) breast cancer cells and its possible influence on their proliferation, motility and invasion. VGSC currents were analysed by whole cell patch clamp recording. Nav1.5 expression and localization, in response to EGF stimulation, was examined by western blotting and immunofluorescence respectively. Cell invasion (under-agarose and Matrigel assays), motility (wound healing assay) and proliferation (MTT assay) were assessed in pII cells in response to VGSC blockers, phenytoin (PHT) and tetrodotoxin (TTX), or by siRNA knockdown of Nav1.5. The effect of PHT and TTX on modulating EGF-induced phosphorylation of Akt and ERK1/2 was determined by western blotting. Total matrix metalloproteinase (MMP) was determined using a fluorometric-based activity assay. The level of various human proteases was detected by using proteome profiler array kit. VGSC currents were detected in pII cells, but were absent in MCF-7. Nav1.5 showed cytoplasmic and perinuclear expression in both MCF-7 and pII cells, with enhanced expression upon EGF stimulation. Treatment of pII cells with PHT, TTX or siRNA significantly reduced invasion towards serum components and EGF, in part through reduction of P-ERK1/2 and proteases such as cathepsin E, kallikrein-10 and MMP-7, as well as total MMP activity. At high concentrations, PHT inhibited motility while TTX reduced cell proliferation. Pharmacological or genetic blockade of Nav1.5 may serve as a potential anti-metastatic therapy for breast cancer.

  2. Inhibition of the catalase activity from Phaseolus vulgaris and Medicago sativa by sodium chloride.

    PubMed

    Tejera García, Noel A; Iribarne, Carmen; Palma, Francisco; Lluch, Carmen

    2007-08-01

    Changes in catalase activity during the development of the Rhizobium-legume symbiosis as well as its response in salinized plants of Phaseolus vulgaris and Medicago sativa, was studied. Besides, it was examined the behavior of the enzyme, isolated from leaves and root nodules, during in vitro incubation with NaCl doses. Nodule catalase activities of both legumes were assayed with several enzyme inhibitors and also purified. Leaf catalase activity of Phaseolus vulgaris and Medicago sativa decreased and increased respectively throughout the ontogeny, but root nodule catalase kept a high and stable value. This last result suggests that both legumes require the maintenance of high nodule catalase in nitrogen-fixing nodules. Under salt stress conditions leaf and nodule catalase activity decreased in both, grain and pasture legumes. Because catalase from leaf of Medicago sativa and nodules of Phaseolus vulgaris were relatively sensitive to NaCl during in vitro experiments, the detoxifying role of this enzyme for H(2)O(2) should be limited in such conditions. Both catalases, from determinate and indeterminate nodules, were affected neither by oxygen nor superoxide radicals but showed a strong (Phaseolus vulgaris) or partial (Medicago sativa) inhibition with dithiothreitol, dithionite and beta-mercaptoethanol. Besides, cyanide was the most potent inhibitor of nodule catalases. Finally, catalases partially purified by immobilized metal ion affinity chromatography migrated at 42 (Phaseolus vulgaris) and 46kDa (Medicago sativa) on SDS-PAGE, whereas native forms on sephacryl S-300 columns exhibited a molecular mass of 59 and 48kDa (Phaseolus vulgaris) and 88 and 53kDa (Medicago sativa).

  3. [Sodium butyrate inhibits HMGB1 expression and release and attenuates concanavalin A-induced acute liver injury in mice].

    PubMed

    Gong, Quan; Chen, Mao-Jian; Wang, Chao; Nie, Hao; Zhang, Yan-Xiang; Shu, Ke-Gang; Li, Gang

    2014-10-25

    The purpose of the present study is to explore the protective effects of sodium butyrate (SB) pretreatment on concanavalin A (Con A)-induced acute liver injury in mice. The model animals were first administered intraperitoneally with SB. Half an hour later, acute liver injury mouse model was established by caudal vein injection with Con A (15 mg/kg). Then, levels of serous alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using standard clinical method by an automated chemistry analyzer, tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) were measured by ELISA, and pathological changes in hepatic tissue were observed by using HE staining and light microscopy. The expression and release of high-mobility group box 1 (HMGB1) were assessed by using reverse transcription polymerase chain reaction (RT-PCR), immunohistochemistry and ELISA. The results showed that the pretreatment of SB significantly protected Con A-treated mice from liver injury as evidenced by the decrease of serum ALT, AST (P < 0.01) and reduction of hepatic tissues necrosis. SB also decreased levels of serous TNF-α and IFN-γ (P < 0.01). Furthermore, the expression and release of HMGB1 were markedly inhibited by SB pretreatment (P < 0.05 or P < 0.01). These results suggest that the attenuating effect of SB on Con A-induced acute liver injury may be due to its role of reducing the TNF-α and IFN-γ production, and inhibiting HMGB1 expression and release.

  4. Inhibition of store-operated Ca2+ entry counteracts the apoptosis of nasopharyngeal carcinoma cells induced by sodium butyrate

    PubMed Central

    Huang, Wei; Ren, Caiping; Huang, Guoling; Liu, Jie; Liu, Weidong; Wang, Lei; Zhu, Bin; Feng, Xiangling; Shi, Jia; Li, Jinlong; Xia, Xiaomeng; Jia, Wei; Chen, Jiawen; Chen, Yuxiang; Jiang, Xingjun

    2017-01-01

    Sodium butyrate (NaBu), a histone deacetylase inhibitor, has demonstrated anti-tumor effects in several cancers, and is a promising candidate chemotherapeutic agent. However, its roles in nasopharyngeal carcinoma (NPC), an endemic malignant disease in Southern China and Southeast Asia, has rarely been studied. In the present study, MTT assay, colony formation assay, flow cytometry analysis and western blotting were performed to explore the influence of NaBu on NPC cells and its underlying mechanism. NaBu induced morphological changes and inhibited proliferation in 5–8F and 6–10B cells. MTT assay revealed that NaBu was cytotoxic to 5–8F and 6–10B cells in a dose- and time-dependent manner. Furthermore, flow cytometry analysis revealed that NaBu induced obvious cell apoptosis in 5–8F and 6–10B cells due to the activation of the mitochondrial apoptosis axis. In addition, flow cytometry analysis and western blotting demonstrated that NaBu could enhance the Ca2+ influx by promoting store-operated Ca2+ entry (SOCE) in 5–8F and 6–10B cells. Inhibition of SOCE by specific inhibitors or downregulated expression of calcium release-activated calcium channel protein 1 and stromal interaction molecule 1 could counteract the apoptosis of NPC cells induced by NaBu. Thus, the current study revealed that enhanced SOCE and activated mitochondrial apoptosis axis may account for the mechanisms of cytotoxicity of NaBu in NPC cells, and that NaBu serves as a promising chemotherapeutic agent in NPC therapy. PMID:28356979

  5. Strawberry phytochemicals inhibit azoxymethane/dextran sodium sulfate-induced colorectal carcinogenesis in Crj: CD-1 mice.

    PubMed

    Shi, Ni; Clinton, Steven K; Liu, Zhihua; Wang, Yongquan; Riedl, Kenneth M; Schwartz, Steven J; Zhang, Xiaoli; Pan, Zui; Chen, Tong

    2015-03-10

    Human and experimental colon carcinogenesis are enhanced by a pro-inflammatory microenvironment. Pharmacologically driven chemopreventive agents and dietary variables are hypothesized to have future roles in the prevention of colon cancer by targeting these processes. The current study was designed to determine the ability of dietary lyophilized strawberries to inhibit inflammation-promoted colon carcinogenesis in a preclinical animal model. Mice were given a single i.p. injection of azoxymethane (10 mg kg-1 body weight). One week after injection, mice were administered 2% (w/v) dextran sodium sulfate in drinking water for seven days and then an experimental diet containing chemically characterized lyophilized strawberries for the duration of the bioassay. Mice fed control diet, or experimental diet containing 2.5%, 5.0% or 10.0% strawberries displayed tumor incidence of 100%, 64%, 75% and 44%, respectively (p < 0.05). The mechanistic studies demonstrate that strawberries reduced expression of proinflammatory mediators, suppressed nitrosative stress and decreased phosphorylation of phosphatidylinositol 3-kinase, Akt, extracellular signal-regulated kinase and nuclear factor kappa B. In conclusion, strawberries target proinflammatory mediators and oncogenic signaling for the preventive efficacies against colon carcinogenesis in mice. This works supports future development of fully characterized and precisely controlled functional foods for testing in human clinical trials for this disease.

  6. Selective inhibition of sodium-calcium exchanger by SEA-0400 decreases early and delayed after depolarization in canine heart.

    PubMed

    Nagy, Zsolt A; Virág, László; Tóth, András; Biliczki, Péter; Acsai, Károly; Bányász, Tamás; Nánási, Péter; Papp, Julius Gy; Varró, András

    2004-12-01

    The sodium-calcium exchanger (NCX) was considered to play an important role in arrhythmogenesis under certain conditions such as heart failure or calcium overload. In the present study, the effect of SEA-0400, a selective inhibitor of the NCX, was investigated on early and delayed afterdepolarizations in canine ventricular papillary muscles and Purkinje fibres by applying conventional microelectrode techniques at 37 degrees C. The amplitude of both early and delayed afterdepolarizations was markedly decreased by 1 microM SEA-0400 from 26.6+/-2.5 to 14.8+/-1.8 mV (n=9, P<0.05) and from 12.5+/-1.7 to 5.9+/-1.4 mV (n=3, P<0.05), respectively. In enzymatically isolated canine ventricular myocytes, SEA-0400 did not change significantly the L-type calcium current and the intracellular calcium transient, studied using the whole-cell configuration of the patch-clamp technique and Fura-2 ratiometric fluorometry. It is concluded that, through the reduction of calcium overload, specific inhibition of the NCX current by SEA-0400 may abolish triggered arrhythmias.

  7. Hydrogen sulfide from a NaHS source attenuates dextran sulfate sodium (DSS)-induced inflammation via inhibiting nuclear factor-κB.

    PubMed

    Chen, Xi; Liu, Xi-shuang

    2016-03-01

    This study investigated the alleviating effects of hydrogen sulfide (H2S), derived from sodium hydrosulfide (NaHS), on inflammation induced by dextran sulfate sodium (DSS) in both in vivo and in vitro models. We found that NaHS injection markedly decreased rectal bleeding, diarrhea, and histological injury in DSS-challenged mice. NaHS (20 μmol/L) reversed DSS-induced inhibition in cell viability in Caco-2 cells and alleviated pro-inflammation cytokine expression in vivo and in vitro, indicating an anti-inflammatory function for H2S. It was also found that H2S may regulate cytokine expression by inhibiting the nuclear factor-κB (NF-κB) signaling pathway. In conclusion, our results demonstrated that H2S alleviated DSS-induced inflammation in vivo and in vitro and that the signal mechanism might be associated with the NF-κB signaling pathway.

  8. Hydrogen sulfide from a NaHS source attenuates dextran sulfate sodium (DSS)-induced inflammation via inhibiting nuclear factor-κB

    PubMed Central

    Chen, Xi; Liu, Xi-shuang

    2016-01-01

    This study investigated the alleviating effects of hydrogen sulfide (H2S), derived from sodium hydrosulfide (NaHS), on inflammation induced by dextran sulfate sodium (DSS) in both in vivo and in vitro models. We found that NaHS injection markedly decreased rectal bleeding, diarrhea, and histological injury in DSS-challenged mice. NaHS (20 μmol/L) reversed DSS-induced inhibition in cell viability in Caco-2 cells and alleviated pro-inflammation cytokine expression in vivo and in vitro, indicating an anti-inflammatory function for H2S. It was also found that H2S may regulate cytokine expression by inhibiting the nuclear factor-κB (NF-κB) signaling pathway. In conclusion, our results demonstrated that H2S alleviated DSS-induced inflammation in vivo and in vitro and that the signal mechanism might be associated with the NF-κB signaling pathway. PMID:26984841

  9. Resistance mechanisms to arsenicals and antimonials.

    PubMed

    Rosen, B P

    1995-01-01

    Salts and organic derivatives of arsenic and antimony are quite toxic. Living organisms have adapted to this toxicity by the evolution of resistance mechanisms. Both prokaryotic and eukaryotic cells develop resistance when exposed to arsenicals or antimonials. In the case of bacteria resistance is conferred by plasmid-encoded arsenical resistance (ars) operons. The genes and gene products of the ars operon of the clinically-isolated conjugative R-factor R773 have been identified and their mechanism of action elucidated. The operon encodes an ATP-driven pump that extrudes arsenite and antimonite from the cells. The lowering of their intracellular concentration results in resistance. Arsenate resistance results from the action of the plasmid-encoded arsenate reductase that reduces arsenate to arsenite, which is then pumped out of the cell.

  10. The heat capacity of solid antimony selenide

    NASA Astrophysics Data System (ADS)

    Pashinkin, A. S.; Malkova, A. S.; Mikhailova, M. S.

    2008-06-01

    The literature data on the heat capacity of solid antimony selenide over the temperature range 53 K- T m were analyzed. The heat capacity of Sb2Se3 was measured from 350 to 600 K on a DSM-2M calorimeter. The experimental data were used to calculate the dependence C p = a + bT + cT -2 and the thermodynamic functions of solid Sb2Se3 over the temperature range 298.15 700 K.

  11. THE CRYSTAL STRUCTURE OF ANTIMONY (III) SULFOBROMIDE, SBSBR,

    DTIC Science & Technology

    ANTIMONY COMPOUNDS, *SULFUR COMPOUNDS, CRYSTAL STRUCTURE , CRYSTAL STRUCTURE , BROMIDES, SYMMETRY(CRYSTALLOGRAPHY), FOURIER ANALYSIS, MOLECULAR STRUCTURE, CRYSTAL LATTICES, CHEMICAL BONDS, X RAY DIFFRACTION.

  12. Açaí Berries Inhibit Colon Tumorigenesis in Azoxymethane/Dextran Sulfate Sodium-Treated Mice

    PubMed Central

    Choi, Yoon Jin; Choi, Yoon Jeong; Kim, Nayoung; Nam, Ryoung Hee; Lee, Seonmin; Lee, Hye Seung; Lee, Ha-Na; Surh, Young-Joon; Lee, Dong Ho

    2017-01-01

    Background/Aims The aim of this study was to investigate the protective effect of açaí against azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colorectal cancer development. Methods The effect of açaí on tumorigenesis was assessed by evaluating tumor incidence, multiplicity and invasiveness in the mouse colon. The levels of myeloperoxidase (MPO) and proinflammatory cytokines (tumor necrosis factor α [TNF-α], interleukin [IL]-1β, and IL-6) were measured via enzyme-linked immunosorbent assay. Protein levels of cyclooxygenase 2 (COX-2), proliferating cell nuclear antigen (PCNA), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated death promoter (Bad) and cleaved-caspase-3 were assessed by immunoblotting. Results Administration of pellets containing 5% açaí powder reduced the incidences of both colonic adenoma and cancer (adenoma, 23.1% vs 76.9%, respectively, p=0.006; cancer, 15.4% vs 76.9%, respectively, p=0.002). In the açaí-treated mice, the MPO, TNF-α, IL-1β and IL-6 levels in the colon were significantly down-regulated. Açaí inhibited PCNA and Bcl-2 expression and increased Bad and cleaved-caspase-3 expression. In vitro studies demonstrated that açaí treatment reduced lipopolysaccharide-induced expression of TNF-α, IL-1β, IL-6 and COX-2 in murine macrophage RAW 264.7 cells. Conclusions Açaí demonstrated protective effects against AOM/DSS-induced colon carcinogenesis, which suggests that the intake of açaí may be beneficial for the prevention of human colon cancer. PMID:27965474

  13. Inhibition of mast cell-derived histamine secretion by cromolyn sodium treatment decreases biliary hyperplasia in cholestatic rodents.

    PubMed

    Kennedy, Lindsey L; Hargrove, Laura A; Graf, Allyson B; Francis, Taylor C; Hodges, Kyle M; Nguyen, Quy P; Ueno, Yoshi; Greene, John F; Meng, Fanyin; Huynh, Victoria D; Francis, Heather L

    2014-12-01

    Cholangiopathies are characterized by dysregulation of the balance between biliary growth and loss. We have shown that histamine (HA) stimulates biliary growth via autocrine mechanisms. To evaluate the paracrine effects of mast cell (MC) stabilization on biliary proliferation, sham or BDL rats were treated by IP-implanted osmotic pumps filled with saline or cromolyn sodium (24 mg/kg BW/day (inhibits MC histamine release)) for 1 week. Serum, liver blocks and cholangiocytes were collected. Histidine decarboxylase (HDC) expression was measured using real-time PCR in cholangiocytes. Intrahepatic bile duct mass (IBDM) was evaluated by IHC for CK-19. MC number was determined using toluidine blue staining and correlated to IBDM. Proliferation was evaluated by PCNA expression in liver sections and purified cholangiocytes. We assessed apoptosis using real-time PCR and IHC for BAX. Expression of MC stem factor receptor, c-kit, and the proteases chymase and tryptase were measured by real-time PCR. HA levels were measured in serum by EIA. In vitro, MCs and cholangiocytes were treated with 0.1% BSA (basal) or cromolyn (25 μM) for up to 48 h prior to assessing HDC expression, HA levels and chymase and tryptase expression. Supernatants from MCs treated with or without cromolyn were added to cholangiocytes before measuring (i) proliferation by MTT assays, (ii) HDC gene expression by real-time PCR and (iii) HA release by EIA. In vivo, cromolyn treatment decreased BDL-induced: (i) IBDM, MC number, and biliary proliferation; (ii) HDC and MC marker expression; and (iii) HA levels. Cromolyn treatment increased cholangiocyte apoptosis. In vitro, cromolyn decreased HA release and chymase and tryptase expression in MCs but not in cholangiocytes. Cromolyn-treated MC supernatants decreased biliary proliferation and HA release. These studies provide evidence that MC histamine is key to biliary proliferation and may be a therapeutic target for the treatment of cholangiopathies.

  14. Acanthopanax versus 3-Methyladenine Ameliorates Sodium Taurocholate-Induced Severe Acute Pancreatitis by Inhibiting the Autophagic Pathway in Rats

    PubMed Central

    Zhou, Guoxiong; Liu, Chun; Wei, Ronglong; Zhu, Shunxing; Xu, Yuefen; Wu, Mengjie; Miao, Qing

    2016-01-01

    Objectives. To observe the therapeutic effects of Acanthopanax and 3-methyladenine against severe acute pancreatitis (SAP). Methods. Sodium taurocholate-induced SAP rats were equally randomized into a SAP group, an Acanthopanax group, and a 3-methyladenine group. Serum amylase levels were determined by ELISA; protein and mRNA expression levels of nucleus nuclear factor kappa B (NF-κB) p65, light chain 3II (LC3-II), and Beclin-1 and mRNA expression levels of Class III phosphatidylinositol 3-kinase (PI3K-III) in pancreas tissue were detected by Western blot and quantitative real-time PCR, respectively; mortality and pathological change of the pancreas were observed at 3, 12, and 24 h after operation. Results. There was no significant difference in mortality between SAP group and both treatment groups (P > 0.05). Serum amylase levels, protein, and mRNA expression levels of nucleus NF-κB p65, LC3-II, and Beclin-1 protein, mRNA expression levels of PI3K-III, and pathological score of the pancreas in both treatment groups were significantly lower than those in SAP group at 12 and 24 h after operation (P < 0.05 or 0.01). The number of autophagosomes and autophagolysosomes of pancreatic acinar cells in both treatment groups was smaller than that in SAP group at 12 and 24 h. Conclusions. Acanthopanax and 3-methyladenine had similar therapeutic effects against SAP in rats. The mechanism may be through inhibiting abnormal autophagy activation of pancreatic acinar cells. PMID:28115794

  15. Inhibition of Clostridium botulinum 52A toxicity and protease activity by sodium acid pyrophosphate in media systems.

    PubMed Central

    Wagner, M K; Busta, F F

    1985-01-01

    The effects of two pH levels (5.55 or 5.85) in combination with 0.4% sodium acid pyrophosphate (SAPP), NaH2PO4 X H2O, Na2HPO4 X 7H2O, or NaCl on the growth and toxicity of Clostridium botulinum 52A were studied. Absorbancy measurements at 630 nm, microscopic observations, and the mouse bioassay procedure were used to observe the effects. At pH 5.55 and 5.85 most control cultures exhibited toxicity when cell lysis began. Vegetative cell development was normal (4 micron long; 1 micron wide). SAPP-containing (0.4%) treatment cultures displayed similar growth and lysis but no or delayed (48 h) toxicity. Cells grown in the SAPP treatment culture were longer and wider (6 micron long; 1.5 micron wide) than in most other treatment cultures. Trypsinization of nontoxic supernatants from 0.4% SAPP resulted in toxicity. Addition of 0.4% SAPP to toxic C. botulinum supernatant delayed but did not prevent death of mice. The addition of various levels of SAPP to toxic supernatants resulted in a decrease in zone size with an increase in the level of SAPP (9 mm with 0.4% SAPP to 7 mm with 1.0% SAPP), using a dual substrate protease assay. A decrease in the zone size also occurred with the supernatant from cultures grown in the presence of SAPP and with Bacillus polymyxa protease dilutions containing 0.4% SAPP. Results suggest that the actual production or function of the protease responsible for toxin activation may have been inhibited by the presence of SAPP. PMID:2992374

  16. [Removal of Antimony in Wastewater by Electrochemical Hydride Generation and the Recovery of Antimony].

    PubMed

    Chen, Jing-jing; Zhang, Guo-ping; Li, Hai-xia; Fu, Zhi-ping; Ouyang, Xiao-xue; Wu, Qiong

    2015-04-01

    An electrochemical hydride generation method was developed for the removal of antimony in wastewater. Hydrogen was generated in the electrolysis of water. Hydrogen reacted with Sb and formed stibine, which volatilized from the solution. Then, stibine was heated and decomposed to elemental Sb. Based on these, Sb in wastewater could be removed and recovered. The highest removal of Sb (76.1%) was achieved in acidic solution (pH = 4). The formation of stibine was proven to contribute most significantly (66.2%) to the removal of antimony in the solution, while the electro-deposition and adsorption also made a small contribution. In the treatment, Sb(V) must be pre-reduced to Sb(III) prior to the formation of stibine. Lead, graphite and tungsten were employed as the materials for cathode, and lead electrode was found most suitable for the removal of antimony.

  17. High Temperature Interactions of Antimony with Nickel

    SciTech Connect

    Marina, Olga A.; Pederson, Larry R.

    2012-07-01

    In this chapter, the surface and bulk interactions of antimony with the Ni-based anodes in solid oxide fuel cells (SOFC) will be discussed. High fuel flexibility is a significant advantage of SOFCs, allowing the direct use of fossil and bio fuels without a hydrogen separation unit. Synthesis gas derived from coal and biomass consists of a mixture of hydrogen, carbon monoxide, carbon dioxide, and steam, but finite amounts of tars and trace impurities such as S, Se, P, As, Sb, Cd, Pb, Cl, etc, are also always present. While synthesis gas is commonly treated with a series of chemical processes and scrubbers to remove the impurities, complete purification is not economical. Antimony is widely distributed in coals. During coal gasification antimony is volatilized, such that contact with the SOFC anodes and other SOFC parts, e.g., interconnect, current collecting wires, fuel gas supplying tubing, is most likely. This chapter addresses the following topics: high temperature Ni - Sb interactions; alteration phase, Ni3Sb, Ni5Sb2, NiSb, formation; thermochemical modeling; impact of Sb on the electrocatalytic activity of Ni toward the fuel oxidation and the presence of other impurities (sulfur, in particular); converted anode structural instability during long-term SOFC operation; comparison with nickel heterogeneous catalysts.

  18. Comparing polyaluminum chloride and ferric chloride for antimony removal.

    PubMed

    Kang, Meea; Kamei, Tasuku; Magara, Yasumoto

    2003-10-01

    Antimony has been one of the contaminants required to be regulated, however, only limited information has been collected to date regarding antimony removal by polyaluminium chloride (PACl) and ferric chloride (FC). Accordingly, the possible use of coagulation by PACl or FC for antimony removal was investigated. Jar tests were used to determine the effects of solution pH, coagulant dosage, and pre-chlorination on the removal of various antimony species. Although high-efficiency antimony removal by aluminum coagulation has been expected because antimony is similar to arsenic in that both antimony and arsenic are a kind of metalloid in group V of the periodic chart, this study indicated: (1) removal density (arsenic or antimony removed per mg coagulant) for antimony by PACl was about one forty-fifth as low as observed for As(V); (2) although the removal of both Sb(III) and Sb(V) by coagulation with FC was much higher than that of PACl, a high coagulant dose of 10.5mg of FeL(-1) at optimal pH of 5.0 was still not sufficient to meet the standard antimony level of 2 microg as SbL(-1) for drinking water when around 6 microg as SbL(-1) were initially present. Consequently, investigation of a more appropriate treatment process is necessary to develop economical Sb reduction; (3) although previous studies concluded that As(V) is more effectively removed than As(III), this study showed that the removal of Sb(III) by coagulation with FC was much more pronounced than that of Sb(V); (4) oxidation of Sb(III) with chlorine decreased the ability of FC to remove antimony. Accordingly, natural water containing Sb(III) under anoxic condition should be coagulated without pre-oxidation.

  19. Study of the synergistic effect of 2-methoxy-4-formylphenol and sodium molybdenum oxide on the corrosion inhibition of 3CR12 ferritic steel in dilute sulphuric acid

    NASA Astrophysics Data System (ADS)

    Loto, Roland Tolulope

    The synergistic effect of the corrosion inhibition properties of 2-methoxy-4-formylphenol and sodium molybdenum oxide on the electrochemical property of 3CR12 ferritic stainless steel in 2M H2SO4 acid solution was assessed through coupon analysis, potentiodynamic polarization technique, IR spectroscopy and micro-analytical technique. Experimental data showed the combined admixture effectively inhibited the steel corrosion at the concentrations analyzed with a maximum inhibition efficiency of 94.47% and 89.71% from coupon analysis and potentiodynamic polarization due to the electrochemical action and inhibition of the steel by the ionized molecules of the inhibiting compound which influenced the mechanism of the redox reactions responsible to corrosion and surface deterioration. Results from corrosion thermodynamic calculations showed chemisorption adsorption mechanism. Infrared spectroscopic images exposed the functional groups of the molecules involved for the corrosion inhibition reaction. Micro-analytical images showed sharp contrast in surface morphology between the inhibited and corroded test specimens under study. Cracks, intergranular and pitting corrosion in addition to severe surface deterioration was observed in the uninhibited samples. Inhibitor adsorption fits the Langmuir isotherm model.

  20. A chewing gum containing 7.5% sodium hexametaphosphate inhibits stain deposition compared with a placebo chewing gum.

    PubMed

    Biesbrock, Aaron R; Walters, Patricia; Bartizek, Robert D

    2004-04-01

    The 2-period, randomized, double-blind, placebo-controlled, crossover study compared the stain-prevention and stain-removal benefit of a chewing gum containing 7.5% sodium hexametaphosphate (measured by digital image analysis) with a placebo chewing gum. The results of this study support that sodium hexametaphosphate delivered from a chewing gum prevents dental stain formation and facilitates stain removal, which leads to a perceptible whitening benefit. The long-term clinical benefits of sodium hexametaphosphate delivered from chewing gum have not been reported in the literature.

  1. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of antimony by automated-hydride atomic absorption spectrophotometry

    USGS Publications Warehouse

    Brown, G.E.; McLain, B.J.

    1994-01-01

    The analysis of natural-water samples for antimony by automated-hydride atomic absorption spectrophotometry is described. Samples are prepared for analysis by addition of potassium and hydrochloric acid followed by an autoclave digestion. After the digestion, potassium iodide and sodium borohydride are added automatically. Antimony hydride (stibine) gas is generated, then swept into a heated quartz cell for determination of antimony by atomic absorption spectrophotometry. Precision and accuracy data are presented. Results obtained on standard reference water samples agree with means established by interlaboratory studies. Spike recoveries for actual samples range from 90 to 114 percent. Replicate analyses of water samples of varying matrices give relative standard deviations from 3 to 10 percent.

  2. In Vitro Inhibition of Cytopathic Effect of Influenza Virus and Human Immunodeficiency Virus by Bamboo Leaf Extract Solution and Sodium Copper Chlorophyllin

    PubMed Central

    Ito, Akiko; Tsuneki, Akeno; Yoshida, Yu; Ryoke, Kazuo; Kaidoh, Toshiyuki; Kageyama, Seiji

    2016-01-01

    Background Although the link between oral and oropharyngeal health status and susceptibility to infection has long been recognized, there is a limit to the selection of antiseptics for oral care. Methods Madin-Darby canine kidney (MDCK) cells were exposed to influenza virus and cultured in the presence or absence of test reagents: bamboo leaf extract solution and sodium copper chrolophyllin. MDCK cells were pre-incubated with the reagents to assess the inhibitory activity at adsorption (viral attachment). Similarly, anti-HIV activity and the inhibitory mechanism at adsorption were assessed by MT-2 cell culture system. Mixture of HIV and bamboo leaf extract solution was fixed and examined by transmission electron microscopy. Results The 50% inhibitory concentration (IC50) of bamboo leaf extract solution against influenza virus and the 50% cytotoxic concentration (CC50) in MDCK cells of the solution lay between 0.0313–0.0625% and 0.5–1.0%. The solution inhibited the influenza virus adsorption at the concentration of 0.5% (P < 0.05). The values of IC50 and CC50 of sodium copper chlorophyllin lay between 50–100 µM and 200–400 µM, respectively. This inhibited the virus adsorption at 200 µM (P < 0.05). The bamboo leaf extract solution showed values of IC50 against HIV and CC50 in MT-2 cells at around 0.0313% and between 0.25–0.5%, respectively. This solution inhibited HIV adsorption at 1.25% (P < 0.05). The IC50 and CC50 of sodium copper chlorophyllin lay between 50–100 µM and 200–400 µM, respectively. Sodium copper chlorophyllin inhibited HIV adsorption at 2.5 mM (P < 0.05). HIV particles survived after the exposure to 0.5% bamboo leaf extract solution. Conclusion Sodium copper chlorophyllin exerted antiviral activities against influenza virus and HIV as the major ingredient of bamboo leaf extract solution by blocking adsorption. This mechanism of action is different completely from the one of povidone-iodine. PMID:27046952

  3. Molecular mechanisms for inhibition of colon cancer cells by combined epigenetic-modulating epigallocatechin gallate and sodium butyrate

    SciTech Connect

    Saldanha, Sabita N.; Kala, Rishabh; Tollefsbol, Trygve O.

    2014-05-15

    Bioactive compounds are considered safe and have been shown to alter genetic and epigenetic profiles of tumor cells. However, many of these changes have been reported at molecular concentrations higher than physiologically achievable levels. We investigated the role of the combinatorial effects of epigallocatechin gallate (EGCG), a predominant polyphenol in green tea, and sodium butyrate (NaB), a dietary microbial fermentation product of fiber, in the regulation of survivin, which is an overexpressed anti-apoptotic protein in colon cancer cells. For the first time, our study showed that the combination treatment induced apoptosis and cell cycle arrest in RKO, HCT-116 and HT-29 colorectal cancer cells. This was found to be regulated by the decrease in HDAC1, DNMT1, survivin and HDAC activity in all three cell lines. A G2/M arrest was observed for RKO and HCT-116 cells, and G1 arrest for HT-29 colorectal cancer cells for combinatorial treatment. Further experimentation of the molecular mechanisms in RKO colorectal cancer (CRC) cells revealed a p53-dependent induction of p21 and an increase in nuclear factor kappa B (NF-κB)-p65. An increase in double strand breaks as determined by gamma-H2A histone family member X (γ-H2AX) protein levels and induction of histone H3 hyperacetylation was also observed with the combination treatment. Further, we observed a decrease in global CpG methylation. Taken together, these findings suggest that at low and physiologically achievable concentrations, combinatorial EGCG and NaB are effective in promoting apoptosis, inducing cell cycle arrest and DNA-damage in CRC cells. - Highlights: • EGCG and NaB as a combination inhibits colorectal cancer cell proliferation. • The combination treatment induces DNA damage, G2/M and G1 arrest and apoptosis. • Survivin is effectively down-regulated by the combination treatment. • p21 and p53 expressions are induced by the combination treatment. • Epigenetic proteins DNMT1 and HDAC1 are

  4. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by this... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Antimony test system. 862.3110 Section 862.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  5. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by this... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Antimony test system. 862.3110 Section 862.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  6. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by this... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Antimony test system. 862.3110 Section 862.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  7. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by this... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Antimony test system. 862.3110 Section 862.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  8. 21 CFR 862.3110 - Antimony test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... antimony, a heavy metal, in urine, blood, vomitus, and stomach contents. Measurements obtained by this... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Antimony test system. 862.3110 Section 862.3110 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...

  9. The exposure to and health effects of antimony

    PubMed Central

    Cooper, Ross G.; Harrison, Adrian P.

    2009-01-01

    Context: This minireview describes the health effects of antimony exposure in the workplace and the environment. Aim: To collate information on the consequences of occupational and environmental exposure to antimony on physiological function and well-being. Methods: The criteria used in the current minireview for selecting articles were adopted from proposed criteria in The International Classification of Functioning, Disability and Health. Articles were classified from an acute and chronic exposure and toxicity thrust. Results: The proportion of utilised and non-utilised articles was tabulated. Antimony toxicity is dependent on the exposure dose, duration, route (breathing, eating, drinking, or skin contact), other chemical exposures, age, sex, nutritional status, family traits, life style, and state of health. Chronic exposure to antimony in the air at levels of 9 mg/m3 may exacerbate irritation of the eyes, skin, and lungs. Long-term inhalation of antimony can potentiate pneumoconiosis, altered electrocardiograms, stomach pain, diarrhea, vomiting, and stomach ulcers, results which were confirmed in laboratory animals. Although there were investigations of the effect of antimony in sudden infant death syndrome, current findings suggest no link. Antimony trioxide exposure is predominant in smelters. Mining and exposure via glass working, soldering, and brazing are also important. Conclusion: Antimony has some useful but undoubtedly harmful effects on health and well-being and measures need to be taken to prevent hazardous exposure of the like. Its biological monitoring in the workplace is essential. PMID:20165605

  10. Removal of antimony from copper by injection of soda ash

    NASA Astrophysics Data System (ADS)

    Stapurewicz, Tadeusz T.; Themelis, Nickolas J.

    1990-12-01

    The removal of Sb from molten copper is of importance in the development of processes which can smelt copper concentrates directly into copper in a single furnace. A promising method is injection of oxygen and sodium carbonate in a modified anode furnace. This study encompassed a thermodynamic analysis of the impurity removal reactions and an experimental investigation of antimony removal from molten copper in a 15 kW induction furnace. The results showed that the reaction was controlled by diffusion of Sb in the metal phase. The reaction between metal and injected flux can be divided into two subprocesses-. (1) “transitory contact” reaction to the injected flux particles as they rise through the melt and (2) “permanent contact” reaction across the interface between the metal bath and the supernatant slag layer. On the basis of the experimental work, the overall volumetric mass transfer coefficient (cm3/s) at 1473 K was expressed in terms of the two subprocesses as follows: (k d A) ov = (k d A) pc + (k d A) tc = 1.25Q{g/0.29} + 0.28 (H Q f ) where Q g is the injection gas flow rate in normal liters per minute, H is the depth of injection in centimeters, and Q f the rate of flux injection in grams per second.

  11. Food additives such as sodium sulphite, sodium benzoate and curcumin inhibit leptin release in lipopolysaccharide-treated murine adipocytes in vitro.

    PubMed

    Ciardi, Christian; Jenny, Marcel; Tschoner, Alexander; Ueberall, Florian; Patsch, Josef; Pedrini, Michael; Ebenbichler, Christoph; Fuchs, Dietmar

    2012-03-01

    Obesity leads to the activation of pro-inflammatory pathways, resulting in a state of low-grade inflammation. Recently, several studies have shown that the exposure to lipopolysaccharide (LPS) could initiate and maintain a chronic state of low-grade inflammation in obese people. As the daily intake of food additives has increased substantially, the aim of the present study was to investigate a potential influence of food additives on the release of leptin, IL-6 and nitrite in the presence of LPS in murine adipocytes. Leptin, IL-6 and nitrite concentrations were analysed in the supernatants of murine 3T3-L1 adipocytes after co-incubation with LPS and the food preservatives, sodium sulphite (SS), sodium benzoate (SB) and the spice and colourant, curcumin, for 24 h. In addition, the kinetics of leptin secretion was analysed. A significant and dose-dependent decrease in leptin was observed after incubating the cells with SB and curcumin for 12 and 24 h, whereas SS decreased leptin concentrations after 24 h of treatment. Moreover, SS increased, while curcumin decreased LPS-stimulated secretion of IL-6, whereas SB had no such effect. None of the compounds that were investigated influenced nitrite production. The food additives SS, SB and curcumin affect the leptin release after co-incubation with LPS from cultured adipocytes in a dose- and time-dependent manner. Decreased leptin release during the consumption of nutrition-derived food additives could decrease the amount of circulating leptin to which the central nervous system is exposed and may therefore contribute to an obesogenic environment.

  12. Chronic exposure to arsenic in drinking water can lead to resistance to antimonial drugs in a mouse model of visceral leishmaniasis.

    PubMed

    Perry, Meghan R; Wyllie, Susan; Raab, Andrea; Feldmann, Joerg; Fairlamb, Alan H

    2013-12-03

    The Indian subcontinent is the only region where arsenic contamination of drinking water coexists with widespread resistance to antimonial drugs that are used to treat the parasitic disease visceral leishmaniasis. We have previously proposed that selection for parasite resistance within visceral leishmaniasis patients who have been exposed to trivalent arsenic results in cross-resistance to the related metalloid antimony, present in the pentavalent state as a complex in drugs such as sodium stibogluconate (Pentostam) and meglumine antimonate (Glucantime). To test this hypothesis, Leishmania donovani was serially passaged in mice exposed to arsenic in drinking water at environmentally relevant levels (10 or 100 ppm). Arsenic accumulation in organs and other tissues was proportional to the level of exposure and similar to that previously reported in human liver biopsies. After five monthly passages in mice exposed to arsenic, isolated parasites were found to be completely refractory to 500 μg · mL(-1) Pentostam compared with the control passage group (38.5 μg · mL(-1)) cultured in vitro in mouse peritoneal macrophages. Reassessment of resistant parasites following further passage for 4 mo in mice without arsenic exposure showed that resistance was stable. Treatment of infected mice with Pentostam confirmed that resistance observed in vitro also occurred in vivo. We conclude that arsenic contamination may have played a significant role in the development of Leishmania antimonial resistance in Bihar because inadequate treatment with antimonial drugs is not exclusive to India, whereas widespread antimonial resistance is.

  13. A Telomeric Cluster of Antimony Resistance Genes on Chromosome 34 of Leishmania infantum

    PubMed Central

    Tejera Nevado, Paloma; Bifeld, Eugenia; Höhn, Katharina

    2016-01-01

    The mechanisms underlying the drug resistance of Leishmania spp. are manifold and not completely identified. Apart from the highly conserved multidrug resistance gene family known from higher eukaryotes, Leishmania spp. also possess genus-specific resistance marker genes. One of them, ARM58, was first identified in Leishmania braziliensis using a functional cloning approach, and its domain structure was characterized in L. infantum. Here we report that L. infantum ARM58 is part of a gene cluster at the telomeric end of chromosome 34 also comprising the neighboring genes ARM56 and HSP23. We show that overexpression of all three genes can confer antimony resistance to intracellular amastigotes. Upon overexpression in L. donovani, ARM58 and ARM56 are secreted via exosomes, suggesting a scavenger/secretion mechanism of action. Using a combination of functional cloning and next-generation sequencing, we found that the gene cluster was selected only under antimonyl tartrate challenge and weakly under Cu2+ challenge but not under sodium arsenite, Cd2+, or miltefosine challenge. The selective advantage is less pronounced in intracellular amastigotes treated with the sodium stibogluconate, possibly due to the known macrophage-stimulatory activity of this drug, against which these resistance markers may not be active. Our data point to the specificity of these three genes for antimony resistance. PMID:27324767

  14. Nanoscaled hydrated antimony (V) oxide as a new approach to first-line antileishmanial drugs

    PubMed Central

    Franco, Antonia MR; Grafova, Iryna; Soares, Fabiane V; Gentile, Gennaro; Wyrepkowski, Claudia DC; Bolson, Marcos A; Sargentini, Ézio; Carfagna, Cosimo; Leskelä, Markku; Grafov, Andriy

    2016-01-01

    Background Coordination compounds of pentavalent antimony have been, and remain, the first-line drugs in leishmaniasis treatment for >70 years. Molecular forms of Sb (V) complexes are commercialized as sodium stibogluconate (Pentostam®) and meglumine antimoniate (MA) (Glucantime®). Ever-increasing drug resistance in the parasites limits the use of antimonials, due to the low drug concentrations being administered against high parasitic counts. Sb5+ toxicity provokes severe side effects during treatment. To enhance therapeutic potency and to increase Sb (V) concentration within the target cells, we decided to try a new active substance form, a hydrosol of Sb2O5·nH2O nanoparticles (NPs), instead of molecular drugs. Methodology/principal findings Sb2O5·nH2O NPs were synthesized by controlled SbCl5 hydrolysis in a great excess of water. Sb2O5·nH2O phase formation was confirmed by X-ray diffraction. The surface of Sb (V) NPs was treated with ligands with a high affinity for target cell membrane receptors. The mean particle size determined by dynamic light scattering and transmission electron microscopy was ~35–45 nm. In vitro tests demonstrated a 2.5–3 times higher antiparasitic activity of Sb (V) nanohybrid hydrosols, when compared to MA solution. A similar comparison for in vivo treatment of experimental cutaneous leishmaniasis with Sb5+ nanohybrids showed a 1.75–1.85 times more effective decrease in the lesions. Microimages of tissue fragments confirmed the presence of NPs inside the cytoplasm of infected macrophages. Conclusion/significance Sb2O5·nH2O hydrosols are proposed as a new form of treatment for cutaneous leishmaniasis caused by Leishmania amazonensis. The NPs penetrate directly into the affected cells, creating a high local concentration of the drug, a precondition to overcoming the parasite resistance to molecular forms of pentavalent antimonials. The nanohybrids are more effective at a lower dose, when compared to MA, the molecular drug. Our

  15. Nitric oxide synthase (NOS) inhibition for one week improves renal sodium and water excretion in cirrhotic rats with ascites.

    PubMed Central

    Martin, P Y; Ohara, M; Gines, P; Xu, D L; St John, J; Niederberger, M; Schrier, R W

    1998-01-01

    Normalization of the increased vascular nitric oxide (NO) generation with low doses of NG-nitro-L-arginine methyl ester (L-NAME) corrects the hemodynamic abnormalities of cirrhotic rats with ascites. We have undertaken this study to investigate the effect of the normalization of vascular NO production, as estimated by aortic cyclic guanosine monophosphate (cGMP) concentration and endothelial nitric oxide synthase (eNOS) protein expression in the aorta and mesenteric artery, on sodium and water excretion. Rats with carbon tetrachloride-induced cirrhosis and ascites were investigated using balance studies. The cirrhotic rats were separated into two groups, one receiving 0.5 mg/kg per day of L-NAME (CIR-NAME) during 7 d, whereas the other group (CIR) was administrated the same volume of vehicle. Two other groups of rats were used as controls, one group treated with L-NAME and another group receiving the same volume of vehicle. Sodium and water excretion was measured on days 0 and 7. On day 8, blood samples were collected for electrolyte and hormone measurements, and aorta and mesenteric arteries were harvested for cGMP determination and nitric oxide synthase (NOS) immunoblotting. Aortic cGMP and eNOS protein expression in the aorta and mesenteric artery were increased in CIR as compared with CIR-NAME. Both cirrhotic groups had a similar decrease in sodium excretion on day 0 (0.7 versus 0.6 mmol per day, NS) and a positive sodium balance (+0.9 versus +1.2 mmol per day, NS). On day 7, CIR-NAME rats had an increase in sodium excretion as compared with the CIR rats (sodium excretion: 2.4 versus 0.7 mmol per day, P < 0.001) and a negative sodium balance (-0.5 versus +0.8 mmol per day, P < 0.001). The excretion of a water load was also increased after L-NAME administration (from 28+/-5% to 65+/-7, P < 0.05). Plasma renin activity, aldosterone and arginine vasopressin were also significantly decreased in the CIR-NAME, as compared with the CIR rats. The results thus indicate

  16. 3-Bromopyruvate and sodium citrate induce apoptosis in human gastric cancer cell line MGC-803 by inhibiting glycolysis and promoting mitochondria-regulated apoptosis pathway.

    PubMed

    Guo, Xingyu; Zhang, Xiaodong; Wang, Tingan; Xian, Shulin; Lu, Yunfei

    2016-06-17

    Cancer cells are mainly dependent on glycolysis to generate adenosine triphosphate (ATP) and intermediates required for cell growth and proliferation. Thus, inhibition of glycolysis might be of therapeutic value in antitumor treatment. Our previously studies had found that both 3-bromopyruvate (BP) and sodium citrate (SCT) can inhibit tumor growth and proliferation in vitro and in vivo. However, the mechanism involved in the BP and SCT mediated antitumor activity is not entirely clear. In this work, it is demonstrated that BP inhibits the enzyme hexokinase (HK) activity and SCT suppresses the phosphofructokinase (PFK) activity respectively, both the two agents decrease viability, ATP generation and lactate content in the human gastric cancer cell line MGC-803. These effects are directly correlated with blockage of glycolysis. Furthermore, BP and SCT can induce the characteristic manifestations of mitochondria-regulated apoptosis, such as down-regulation of anti-apoptosis proteins Bcl-2 and Survivin, up-regulation of pro-apoptosis protein Bax, activation of caspase-3, as well as leakage of cytochrome c (Cyt-c). In summary, our results provided evidences that BP and SCT inhibit the MGC-803 cells growth and proliferation might be correlated with inhibiting glycolysis and promoting mitochondria-regulated apoptosis.

  17. 3-Bromopyruvate and sodium citrate target glycolysis, suppress survivin, and induce mitochondrial-mediated apoptosis in gastric cancer cells and inhibit gastric orthotopic transplantation tumor growth

    PubMed Central

    WANG, TING-AN; ZHANG, XIAO-DONG; GUO, XING-YU; XIAN, SHU-LIN; LU, YUN-FEI

    2016-01-01

    Glycolysis is the primary method utilized by cancer cells to produce the energy (adenosine triphosphate, ATP) required for cell proliferation. Therefore, inhibition of glycolysis may inhibit tumor growth. We previously found that both 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) can inhibit glycolysis in vitro; however, the underlying inhibitory mechanisms remain unclear. In the present study, we used a human gastric cancer cell line (SGC-7901) and an orthotopic transplantation tumor model in nude mice to explore the specific mechanisms of 3-BrPA and SCT. We found that both 3-BrPA and SCT effectively suppressed cancer cell proliferation, arrested the cell cycle, induced apoptosis, and decreased the production of lactate and ATP. 3-BrPA significantly reduced the glycolytic enzyme hexokinase activity, while SCT selectively inhibited phosphofructokinase-1 activity. Furthermore, 3-BrPA and SCT upregulated the expression of pro-apoptotic proteins (Bax, cytochrome c, and cleaved caspase-3) and downregulated the expression of anti-apoptotic proteins (Bcl-2 and survivin). Finally, our animal model of gastric cancer indicated that intraperitoneal injection of 3-BrPA and SCT suppressed orthotopic transplantation tumor growth and induced tumor apoptosis. Taken together, these results suggest that 3-BrPA and SCT selectively suppress glycolytic enzymes, decrease ATP production, induce mitochondrial-mediated apoptosis, downregulate survivin, and inhibit tumor growth. Moreover, an intraperitoneal injection is an effective form of administration of 3-BrPA and SCT. PMID:26708213

  18. 3-bromopyruvate and sodium citrate target glycolysis, suppress survivin, and induce mitochondrial-mediated apoptosis in gastric cancer cells and inhibit gastric orthotopic transplantation tumor growth.

    PubMed

    Wang, Ting-An; Zhang, Xiao-Dong; Guo, Xing-Yu; Xian, Shu-Lin; Lu, Yun-Fei

    2016-03-01

    Glycolysis is the primary method utilized by cancer cells to produce the energy (adenosine triphosphate, ATP) required for cell proliferation. Therefore, inhibition of glycolysis may inhibit tumor growth. We previously found that both 3-bromopyruvate (3-BrPA) and sodium citrate (SCT) can inhibit glycolysis in vitro; however, the underlying inhibitory mechanisms remain unclear. In the present study, we used a human gastric cancer cell line (SGC-7901) and an orthotopic transplantation tumor model in nude mice to explore the specific mechanisms of 3-BrPA and SCT. We found that both 3-BrPA and SCT effectively suppressed cancer cell proliferation, arrested the cell cycle, induced apoptosis, and decreased the production of lactate and ATP. 3-BrPA significantly reduced the glycolytic enzyme hexokinase activity, while SCT selectively inhibited phosphofructokinase-1 activity. Furthermore, 3-BrPA and SCT upregulated the expression of pro-apoptotic proteins (Bax, cytochrome c, and cleaved caspase-3) and downregulated the expression of anti-apoptotic proteins (Bcl-2 and survivin). Finally, our animal model of gastric cancer indicated that intraperitoneal injection of 3-BrPA and SCT suppressed orthotopic transplantation tumor growth and induced tumor apoptosis. Taken together, these results suggest that 3-BrPA and SCT selectively suppress glycolytic enzymes, decrease ATP production, induce mitochondrial-mediated apoptosis, downregulate survivin, and inhibit tumor growth. Moreover, an intraperitoneal injection is an effective form of administration of 3-BrPA and SCT.

  19. Inhibition of collagen synthesis by select calcium and sodium channel blockers can be mitigated by ascorbic acid and ascorbyl palmitate.

    PubMed

    Ivanov, Vadim; Ivanova, Svetlana; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

    2016-01-01

    Calcium, sodium and potassium channel blockers are widely prescribed medications for a variety of health problems, most frequently for cardiac arrhythmias, hypertension, angina pectoris and other disorders. However, chronic application of channel blockers is associated with numerous side effects, including worsening cardiac pathology. For example, nifedipine, a calcium-channel blocker was found to be associated with increased mortality and increased risk for myocardial infarction. In addition to the side effects mentioned above by different channel blockers, these drugs can cause arterial wall damage, thereby contributing to vascular wall structure destabilization and promoting events facilitating rupture of plaques. Collagen synthesis is regulated by ascorbic acid, which is also essential for its optimum structure as a cofactor in lysine and proline hydroxylation, a precondition for optimum crosslinking of collagen and elastin. Therefore, the main objective in this study was to evaluate effects of various types of channel blockers on intracellular accumulation and cellular functions of ascorbate, specifically in relation to formation and extracellular deposition of major collagen types relevant for vascular function. Effects of select Na- and Ca- channel blockers on collagen synthesis and deposition were evaluated in cultured human dermal fibroblasts and aortic smooth muscle cells by immunoassay. All channel blockers tested demonstrated inhibitory effects on collagen type I deposition to the ECM by fibroblasts, each to a different degree. Ascorbic acid significantly increased collagen I ECM deposition. Nifedipine (50 µM), a representative of channel blockers tested, significantly reduced ascorbic acid and ascorbyl palmitate-dependent ECM deposition of collagen type l and collagen type lV by cultured aortic smooth muscle cells. In addition, nifedipine (50 µM) significantly reduced ascorbate-dependent collagen type l and type lV synthesis by cultured aortic smooth

  20. Inhibition of collagen synthesis by select calcium and sodium channel blockers can be mitigated by ascorbic acid and ascorbyl palmitate

    PubMed Central

    Ivanov, Vadim; Ivanova, Svetlana; Kalinovsky, Tatiana; Niedzwiecki, Aleksandra; Rath, Matthias

    2016-01-01

    Calcium, sodium and potassium channel blockers are widely prescribed medications for a variety of health problems, most frequently for cardiac arrhythmias, hypertension, angina pectoris and other disorders. However, chronic application of channel blockers is associated with numerous side effects, including worsening cardiac pathology. For example, nifedipine, a calcium-channel blocker was found to be associated with increased mortality and increased risk for myocardial infarction. In addition to the side effects mentioned above by different channel blockers, these drugs can cause arterial wall damage, thereby contributing to vascular wall structure destabilization and promoting events facilitating rupture of plaques. Collagen synthesis is regulated by ascorbic acid, which is also essential for its optimum structure as a cofactor in lysine and proline hydroxylation, a precondition for optimum crosslinking of collagen and elastin. Therefore, the main objective in this study was to evaluate effects of various types of channel blockers on intracellular accumulation and cellular functions of ascorbate, specifically in relation to formation and extracellular deposition of major collagen types relevant for vascular function. Effects of select Na- and Ca- channel blockers on collagen synthesis and deposition were evaluated in cultured human dermal fibroblasts and aortic smooth muscle cells by immunoassay. All channel blockers tested demonstrated inhibitory effects on collagen type I deposition to the ECM by fibroblasts, each to a different degree. Ascorbic acid significantly increased collagen I ECM deposition. Nifedipine (50 µM), a representative of channel blockers tested, significantly reduced ascorbic acid and ascorbyl palmitate-dependent ECM deposition of collagen type l and collagen type lV by cultured aortic smooth muscle cells. In addition, nifedipine (50 µM) significantly reduced ascorbate-dependent collagen type l and type lV synthesis by cultured aortic smooth

  1. Antimony ore in the Fairbanks district, Alaska

    USGS Publications Warehouse

    Killeen, Pemberton Lewis; Mertie, John B.

    1951-01-01

    Antimony-bearing ores in the Fairbanks district, Alaska, are found principally in two areas, the extremities of which are at points 10 miles west and 23 miles northeast of Fairbanks; and one of two minor areas lies along this same trend 30 miles farther to the northeast. These areas are probably only local manifestations of mineralization that affected a much broader area and formed antimony-bearing deposits in neighboring districts, the closest of which is 50 miles away. The ores were exposed largely as a result of lode gold mining, but at two periods in the past, high prices for antimony ore warranted an independent production and about 2500 tons of stibnite ore was shipped. The sulfide deposits occupy the same fractures along which a gold-quartz mineralization of greater economic importance occurred; and both are probably genetically related to igneous rocks which intrude the schistose country rock. The sulfide is in part contemporaneous with some late-stage quartz in which it occurs as disseminated crystals; and in part the latest filling in the mineralized zones where it forms kidney-shaped masses of essentially solid sulfide. One extremely long mass must have contained nearly 100 tons of ore, but the average of the larger kidneys is closer to several tons. Much of the ore is stibnite, with quartz as a minor impurity, and assays show the tenor to vary from 40 to 65 percent antimony. Sulphantimonites are less abundant but likewise occur as disseminated crystals and as kidney-shaped bodies. Antimony oxides appear on the weathered surface and along fractures within the sulfide ore. Deposits containing either stibnite or sulphantimonite are known at more than 50 localities, but only eighteen have produced ore and the bulk of this came from the mines. The geology of the deposit, and the nature, extent, and period of the workings are covered in the detailed descriptions of individual occurrences. Several geologic and economic factors, which greatly affect

  2. Gastrointestinal Inhibition of Sodium-Hydrogen Exchanger 3 Reduces Phosphorus Absorption and Protects against Vascular Calcification in CKD.

    PubMed

    Labonté, Eric D; Carreras, Christopher W; Leadbetter, Michael R; Kozuka, Kenji; Kohler, Jill; Koo-McCoy, Samantha; He, Limin; Dy, Edward; Black, Deborah; Zhong, Ziyang; Langsetmo, Ingrid; Spencer, Andrew G; Bell, Noah; Deshpande, Desiree; Navre, Marc; Lewis, Jason G; Jacobs, Jeffrey W; Charmot, Dominique

    2015-05-01

    In CKD, phosphate retention arising from diminished GFR is a key early step in a pathologic cascade leading to hyperthyroidism, metabolic bone disease, vascular calcification, and cardiovascular mortality. Tenapanor, a minimally systemically available inhibitor of the intestinal sodium-hydrogen exchanger 3, is being evaluated in clinical trials for its potential to (1) lower gastrointestinal sodium absorption, (2) improve fluid overload-related symptoms, such as hypertension and proteinuria, in patients with CKD, and (3) reduce interdialytic weight gain and intradialytic hypotension in ESRD. Here, we report the effects of tenapanor on dietary phosphorous absorption. Oral administration of tenapanor or other intestinal sodium-hydrogen exchanger 3 inhibitors increased fecal phosphorus, decreased urine phosphorus excretion, and reduced [(33)P]orthophosphate uptake in rats. In a rat model of CKD and vascular calcification, tenapanor reduced sodium and phosphorus absorption and significantly decreased ectopic calcification, serum creatinine and serum phosphorus levels, circulating phosphaturic hormone fibroblast growth factor-23 levels, and heart mass. These results indicate that tenapanor is an effective inhibitor of dietary phosphorus absorption and suggest a new approach to phosphate management in renal disease and associated mineral disorders.

  3. Synthetic aspects, spectral, thermal studies and antimicrobial screening on bis(N,N-dimethyldithiocarbamato-S,S‧)antimony(III) complexes with oxo or thio donor ligands

    NASA Astrophysics Data System (ADS)

    Chauhan, H. P. S.; Carpenter, Jaswant; Joshi, Sapana

    2014-09-01

    The bis(N,N-dimethyldithiocarbamato-S,S‧)antimony(III) complexes have been obtained by the reaction of chloro bis(N,N-dimethyldithiocarbamato-S,S‧)antimony(III) with corresponding oxo or thio donor ligands such as sodium benzoate 1, sodium thioglycolate 2, phenol 3, sodium 1-propanethiolate 4, potassium thioacetate 5, sodium salicylate 6, ethane-1,2-dithiolate 7 and disodium oxalate 8. These complexes have been characterized by the physicochemical [melting point, molecular weight determination and elemental analysis (C, H, N, S and Sb)], spectral [UV-Visible, FT-IR, far IR, NMR (1H and 13C)], thermogravimetric (TG & DTA) analysis, ESI-Mass and powder X-ray diffraction studies. Thermogravimetric analysis of the complexes confirmed the final decomposition product as highly pure antimony sulfide (Sb2S3) and powder X-ray diffraction studies show that the complexes are in lower symmetry with monoclinic crystal lattice and nano-ranged particle size (11.51-20.82 nm). The complexes have also been screened against some bacterial and fungal strains for their antibacterial and antifungal activities and compared with standard drugs. These show that the complexes have greater activities against some human pathogenic bacteria and fungi than the activities of standard drugs.

  4. Hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced severe acute pancreatitis by inhibiting ROS and NF-κB pathway.

    PubMed

    Shi, Qiao; Liao, Kang-Shu; Zhao, Kai-Liang; Wang, Wei-Xing; Zuo, Teng; Deng, Wen-Hong; Chen, Chen; Yu, Jia; Guo, Wen-Yi; He, Xiao-Bo; Abliz, Ablikim; Wang, Peng; Zhao, Liang

    2015-01-01

    Hydrogen (H2), a new antioxidant, was reported to reduce (•)OH and ONOO(-) selectively and inhibit certain proinflammatory mediators to product, without disturbing metabolic redox reactions or ROS involved in cell signaling. We herein aim to explore its protective effects on acute renal injury in sodium taurocholate-induced acute pancreatitis and its possible mechanisms. Rats were injected with hydrogen-rich saline (HRS group) or normal saline (SO and SAP group) through tail intravenously (6 mL/kg) and compensated subcutaneously (20 mL/kg) after successful modeling. Results showed that hydrogen-rich saline attenuated the following: (1) serum Cr and BUN, (2) pancreatic and renal pathological injuries, (3) renal MDA, (4) renal MPO, (5) serum IL-1β, IL-6, and renal TNF-α, HMGB1, and (6) tyrosine nitration, IκB degradation, and NF-κB activation in renal tissues. In addition, it increased the level of IL-10 and SOD activity in renal tissues. These results proved that hydrogen-rich saline attenuates acute renal injury in sodium taurocholate-induced acute pancreatitis, presumably because of its detoxification activity against excessive ROS, and inhibits the activation of NF-κB by affecting IκB nitration and degradation. Our findings highlight the potential value of hydrogen-rich saline as a new therapeutic method on acute renal injury in severe acute pancreatitis clinically.

  5. Inhibition of oxytocin-induced but not angiotensin-induced rat uterine contractions following exposure to sodium sulfide

    SciTech Connect

    Hayden, L.J.; Franklin, K.J.; Roth, S.H.; Moore, G.J. )

    1989-01-01

    Low concentrations of sodium sulfide reversibly attenuate the contractile response of the isolate rat uterus to oxytocin without affecting angiotensin II responsiveness. These findings suggest that functionally important disulfide bonds in the rat uterine oxytocin receptor, but not the angiotensin receptor, are sensitive to hydrosulfide ion. Reduction of oxytocin receptors by hydrosulfide ion may be a mechanism by which low level of H{sub 2}S delay parturition in rats.

  6. Sodium tanshinone IIA sulfonate inhibits hypoxia-induced enhancement of SOCE in pulmonary arterial smooth muscle cells via the PKG-PPAR-γ signaling axis.

    PubMed

    Jiang, Qian; Lu, Wenju; Yang, Kai; Hadadi, Cyrus; Fu, Xin; Chen, Yuqin; Yun, Xin; Zhang, Jie; Li, Meichan; Xu, Lei; Tang, Haiyang; Yuan, Jason X-J; Wang, Jian; Sun, Dejun

    2016-07-01

    Our laboratory previously showed that sodium tanshinone IIA sulfonate (STS) inhibited store-operated Ca(2+) entry (SOCE) through store-operated Ca(2+) channels (SOCC) via downregulating the expression of transient receptor potential canonical proteins (TRPC), which contribute to the formation of SOCC (Wang J, Jiang Q, Wan L, Yang K, Zhang Y, Chen Y, Wang E, Lai N, Zhao L, Jiang H, Sun Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 48: 125-134, 2013). The detailed molecular mechanisms by which STS inhibits SOCE and downregulates TRPC, however, remain largely unknown. We have previously shown that, under hypoxic conditions, inhibition of protein kinase G (PKG) and peroxisome proliferator-activated receptor-γ (PPAR-γ) signaling axis results in the upregulation of TRPC (Wang J, Yang K, Xu L, Zhang Y, Lai N, Jiang H, Zhang Y, Zhong N, Ran P, Lu W. Am J Respir Cell Mol Biol 49: 231-240, 2013). This suggests that strategies targeting the restoration of this signaling pathway may be an effective treatment strategy for pulmonary hypertension. In this study, our results demonstrated that STS treatment can effectively prevent the hypoxia-mediated inhibition of the PKG-PPAR-γ signaling axis in rat distal pulmonary arterial smooth muscle cells (PASMCs) and distal pulmonary arteries. These effects of STS treatment were blocked by pharmacological inhibition or specific small interfering RNA knockdown of either PKG or PPAR-γ. Moreover, targeted PPAR-γ agonist markedly enhanced the beneficial effects of STS. These results comprehensively suggest that STS treatment can prevent hypoxia-mediated increases in intracellular calcium homeostasis and cell proliferation, by targeting and restoring the hypoxia-inhibited PKG-PPAR-γ signaling pathway in PASMCs.

  7. Voltage-Independent Inhibition of the Tetrodotoxin-Sensitive Sodium Currents by Oxotremorine and Angiotensin II in Rat Sympathetic Neurons.

    PubMed

    Puente, Erika I; De la Cruz, Lizbeth; Arenas, Isabel; Elias-Viñas, David; Garcia, David E

    2016-04-01

    Tetrodotoxin-sensitive Na(+) currents have been extensively studied because they play a major role in neuronal firing and bursting. In this study, we showed that voltage-dependent Na(+) currents are regulated in a slow manner by oxotremorine (oxo-M) and angiotensin II in rat sympathetic neurons. We found that these currents can be readily inhibited through a signaling pathway mediated by G proteins and phospholipase C (PLC) β1. This inhibition is slowly established, pertussis toxin-insensitive, partially reversed within tens of seconds after oxo-M washout, and not relieved by a strong depolarization, suggesting a voltage-insensitive mechanism of inhibition. Specificity of the M1 receptor was tested by the MT-7 toxin. Activation and inactivation curves showed no shift in the voltage dependency under the inhibition by oxo-M. This inhibition is blocked by a PLC inhibitor (U73122, 1-(6-{[(17β)-3-Methoxyestra-1,3,5(10)-trien-17-yl]amino}hexyl)-1H-pyrrole-2,5-dione), and recovery from inhibition is prevented by wortmannin, a PI3/4 kinase inhibitor. Hence, the pathway involves Gq/11 and is mediated by a diffusible second messenger. Oxo-M inhibition is occluded by screening phosphatidylinositol 4,5-bisphosphate (PIP2)-negative charges with poly-l-lysine and prevented by intracellular dialysis with a PIP2 analog. In addition, bisindolylmaleimide I, a specific ATP-competitive protein kinase C (PKC) inhibitor, rules out that this inhibition may be mediated by this protein kinase. Furthermore, oxo-M-induced suppression of Na(+) currents remains unchanged when neurons are treated with calphostin C, a PKC inhibitor that targets the diacylglycerol-binding site of the kinase. These results support a general mechanism of Na(+) current inhibition that is widely present in excitable cells through modulation of ion channels by specific G protein-coupled receptors.

  8. Silver and Nitrate Oppositely Modulate Antimony Susceptibility through Aquaglyceroporin 1 in Leishmania (Viannia) Species

    PubMed Central

    Andrade, Juvana M.; Baba, Elio H.; Machado-de-Avila, Ricardo A.; Chavez-Olortegui, Carlos; Demicheli, Cynthia P.; Frézard, Frédéric

    2016-01-01

    Antimony (Sb) resistance in leishmaniasis chemotherapy has become one of the major challenges to the control of this spreading worldwide public health problem. Since the plasma membrane pore-forming protein aquaglyceroporin 1 (AQP1) is the major route of Sb uptake in Leishmania, functional studies are relevant to characterize drug transport pathways in the parasite. We generated AQP1-overexpressing Leishmania guyanensis and L. braziliensis mutants and investigated their susceptibility to the trivalent form of Sb (SbIII) in the presence of silver and nitrate salts. Both AQP1-overexpressing lines presented 3- to 4-fold increased AQP1 expression levels compared with those of their untransfected counterparts, leading to an increased SbIII susceptibility of about 2-fold. Competition assays using silver nitrate, silver sulfadiazine, or silver acetate prior to SbIII exposure increased parasite growth, especially in AQP1-overexpressing mutants. Surprisingly, SbIII-sodium nitrate or SbIII-potassium nitrate combinations showed significantly enhanced antileishmanial activities compared to those of SbIII alone, especially against AQP1-overexpressing mutants, suggesting a putative nitrate-dependent modulation of AQP1 activity. The intracellular level of antimony quantified by graphite furnace atomic absorption spectrometry showed that the concomitant exposure to SbIII and nitrate favors antimony accumulation in the parasite, increasing the toxicity of the drug and culminating with parasite death. This is the first report showing evidence of AQP1-mediated SbIII susceptibility modulation by silver in Leishmania and suggests the potential antileishmanial activity of the combination of nitrate salts and SbIII. PMID:27161624

  9. Antimony film sensor for sensitive rare earth metal analysis in environmental samples.

    PubMed

    Makombe, Martin; van der Horst, Charlton; Silwana, Bongiwe; Iwuoha, Emmanuel; Somerset, Vernon

    2016-07-02

    A sensor for the adsorptive stripping voltammetric determination of rare earth elements has been developed. The electrochemical procedure is based on the oxidation of the rare earth elements complexed with alizarin complexone at a glassy carbon electrode that was in situ modified with an antimony film, during an anodic scan from -0.2 V to 1.1 V (vs. Ag/AgCl) and deposition potential of -0.1 V (vs. Ag/AgCl). The factors influencing the adsorptive stripping capability were optimised, including the complexing agent concentration, plating concentration of antimony and deposition time. The detection of rare earth elements (La, Ce and Pr) were realised in 0.08 M sodium acetate (pH = 5.8) solution as supporting electrolyte, with 2 × 10(-6) M alizarin complexone and 1.0 mg L(-1) antimony solution. Under the optimised conditions, a deposition time of 360 s was obtained and a linear response was observed between 1 and 25 µg L(-1). The reproducibility of the voltammetric measurements was found to be within 5.0% RSD for 12 replicate measurements of cerium(III) concentration of 5 µg L(-1) using the same electrode surface. The detection limits obtained using stripping analysis was 0.06, 0.42 and 0.71 μg L(-1) for Ce(III), La(III) and Pr(III), respectively. The developed sensor has been successfully applied for the determination of cerium, lanthanum and praseodymium in municipal tap water samples.

  10. Silver and Nitrate Oppositely Modulate Antimony Susceptibility through Aquaglyceroporin 1 in Leishmania (Viannia) Species.

    PubMed

    Andrade, Juvana M; Baba, Elio H; Machado-de-Avila, Ricardo A; Chavez-Olortegui, Carlos; Demicheli, Cynthia P; Frézard, Frédéric; Monte-Neto, Rubens L; Murta, Silvane M F

    2016-08-01

    Antimony (Sb) resistance in leishmaniasis chemotherapy has become one of the major challenges to the control of this spreading worldwide public health problem. Since the plasma membrane pore-forming protein aquaglyceroporin 1 (AQP1) is the major route of Sb uptake in Leishmania, functional studies are relevant to characterize drug transport pathways in the parasite. We generated AQP1-overexpressing Leishmania guyanensis and L. braziliensis mutants and investigated their susceptibility to the trivalent form of Sb (Sb(III)) in the presence of silver and nitrate salts. Both AQP1-overexpressing lines presented 3- to 4-fold increased AQP1 expression levels compared with those of their untransfected counterparts, leading to an increased Sb(III) susceptibility of about 2-fold. Competition assays using silver nitrate, silver sulfadiazine, or silver acetate prior to Sb(III) exposure increased parasite growth, especially in AQP1-overexpressing mutants. Surprisingly, Sb(III)-sodium nitrate or Sb(III)-potassium nitrate combinations showed significantly enhanced antileishmanial activities compared to those of Sb(III) alone, especially against AQP1-overexpressing mutants, suggesting a putative nitrate-dependent modulation of AQP1 activity. The intracellular level of antimony quantified by graphite furnace atomic absorption spectrometry showed that the concomitant exposure to Sb(III) and nitrate favors antimony accumulation in the parasite, increasing the toxicity of the drug and culminating with parasite death. This is the first report showing evidence of AQP1-mediated Sb(III) susceptibility modulation by silver in Leishmania and suggests the potential antileishmanial activity of the combination of nitrate salts and Sb(III).

  11. Biogeochemistry of arsenic and antimony in the North Pacific Ocean

    NASA Astrophysics Data System (ADS)

    Cutter, Gregory A.; Cutter, Lynda S.

    2006-05-01

    The biogeochemical cycles of the metalloid elements arsenic and antimony were examined along a 15,000 km surface water transect and at 9 vertical profile stations in the western North Pacific Ocean as part of the 2002 IOC Contaminant Baseline Survey. Results show that the speciation of dissolved arsenic (As III, As V, and methylated As) was subtly controlled by the arsenate (AsV)/phosphate ratio. An additional fraction of presumed organic arsenic previously reported in coastal waters was also present (˜15% of the total As) in oceanic surface waters. Dissolved inorganic antimony displayed mildly scavenged behavior that was confirmed by correlations with aluminum, but atmospheric inputs that may be anthropogenic in origin also affected its concentrations. Monomethyl antimony, the predominant organic form of the element, behaved almost conservatively throughout the water column, radically changing the known biogeochemical cycle of antimony.

  12. Hydrogen sulfide decreases β-adrenergic agonist-stimulated lung liquid clearance by inhibiting ENaC-mediated transepithelial sodium absorption.

    PubMed

    Agné, Alisa M; Baldin, Jan-Peter; Benjamin, Audra R; Orogo-Wenn, Maria C; Wichmann, Lukas; Olson, Kenneth R; Walters, Dafydd V; Althaus, Mike

    2015-04-01

    In pulmonary epithelia, β-adrenergic agonists regulate the membrane abundance of the epithelial sodium channel (ENaC) and, thereby, control the rate of transepithelial electrolyte absorption. This is a crucial regulatory mechanism for lung liquid clearance at birth and thereafter. This study investigated the influence of the gaseous signaling molecule hydrogen sulfide (H2S) on β-adrenergic agonist-regulated pulmonary sodium and liquid absorption. Application of the H2S-liberating molecule Na2S (50 μM) to the alveolar compartment of rat lungs in situ decreased baseline liquid absorption and abrogated the stimulation of liquid absorption by the β-adrenergic agonist terbutaline. There was no additional effect of Na2S over that of the ENaC inhibitor amiloride. In electrophysiological Ussing chamber experiments with native lung epithelia (Xenopus laevis), Na2S inhibited the stimulation of amiloride-sensitive current by terbutaline. β-adrenergic agonists generally increase ENaC abundance by cAMP formation and activation of PKA. Activation of this pathway by forskolin and 3-isobutyl-1-methylxanthine increased amiloride-sensitive currents in H441 pulmonary epithelial cells. This effect was inhibited by Na2S in a dose-dependent manner (5-50 μM). Na2S had no effect on cellular ATP concentration, cAMP formation, and activation of PKA. By contrast, Na2S prevented the cAMP-induced increase in ENaC activity in the apical membrane of H441 cells. H441 cells expressed the H2S-generating enzymes cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase, and they produced H2S amounts within the employed concentration range. These data demonstrate that H2S prevents the stimulation of ENaC by cAMP/PKA and, thereby, inhibits the proabsorptive effect of β-adrenergic agonists on lung liquid clearance.

  13. Characterization of the Antimonial Antileishmanial Agent Meglumine Antimonate (Glucantime)

    PubMed Central

    Roberts, William L.; McMurray, Walter J.; Rainey, Petrie M.

    1998-01-01

    Meglumine antimonate (Glucantime), a drug of choice for the treatment of leishmaniasis, is produced by the reaction of pentavalent antimony with N-methyl-d-glucamine, a carbohydrate derivative. We investigated the structure and composition of meglumine antimonate, which remain poorly understood, despite 50 years of use. Measurement of the antimony content of meglumine antimonate powder indicated a 1:1.37 molar ratio of antimony to N-methyl-d-glucamine. Osmolality measurements performed with meglumine antimonate solutions demonstrated an average of 1.43 antimony atoms per molecule of meglumine antimonate. The osmolality of a 1:10 dilution of stock meglumine antimonate increased by 45% over 8 days, suggesting hydrolysis to less complex species. A comparison of the proton nuclear magnetic resonance spectra of N-methyl-d-glucamine and meglumine antimonate revealed an increase in complexity in the latter but with all of the resonances of the former still being evident, consistent with the presence of coordination complexes between antimony and each of the N-methyl-d-glucamine hydroxyls. Fast atom bombardment and electrospray ionization mass spectrometry coupled with several derivatization procedures provided evidence that up to four N-methyl-d-glucamine hydroxyls are coordinated with each antimony. A series of oligomers were observed. The major moiety has a molecular mass of 507 atomic mass units and consists of NMG-Sb-NMG, where Sb represents antimony and NMG represents N-methyl-d-glucamine. Additional species containing up to four antimony atoms and five N-methyl-d-glucamine moieties and corresponding to the general form (NMG-Sb)n-NMG are also present. These results suggest that this agent is a complex mixture that exists in equilibrium in aqueous solution. PMID:9593130

  14. Microbial Methylation of Metalloids: Arsenic, Antimony, and Bismuth

    PubMed Central

    Bentley, Ronald; Chasteen, Thomas G.

    2002-01-01

    A significant 19th century public health problem was that the inhabitants of many houses containing wallpaper decorated with green arsenical pigments experienced illness and death. The problem was caused by certain fungi that grew in the presence of inorganic arsenic to form a toxic, garlic-odored gas. The garlic odor was actually put to use in a very delicate microbiological test for arsenic. In 1933, the gas was shown to be trimethylarsine. It was not until 1971 that arsenic methylation by bacteria was demonstrated. Further research in biomethylation has been facilitated by the development of delicate techniques for the determination of arsenic species. As described in this review, many microorganisms (bacteria, fungi, and yeasts) and animals are now known to biomethylate arsenic, forming both volatile (e.g., methylarsines) and nonvolatile (e.g., methylarsonic acid and dimethylarsinic acid) compounds. The enzymatic mechanisms for this biomethylation are discussed. The microbial conversion of sodium arsenate to trimethylarsine proceeds by alternate reduction and methylation steps, with S-adenosylmethionine as the usual methyl donor. Thiols have important roles in the reductions. In anaerobic bacteria, methylcobalamin may be the donor. The other metalloid elements of the periodic table group 15, antimony and bismuth, also undergo biomethylation to some extent. Trimethylstibine formation by microorganisms is now well established, but this process apparently does not occur in animals. Formation of trimethylbismuth by microorganisms has been reported in a few cases. Microbial methylation plays important roles in the biogeochemical cycling of these metalloid elements and possibly in their detoxification. The wheel has come full circle, and public health considerations are again important. PMID:12040126

  15. Sodium arsenite-induced inhibition of cell proliferation is related to inhibition of IL-2 mRNA expression in mouse activated T cells.

    PubMed

    Conde, Patricia; Acosta-Saavedra, Leonor C; Goytia-Acevedo, Raquel C; Calderon-Aranda, Emma S

    2007-04-01

    A proposed mechanism for the As-induced inhibition of cell proliferation is the inhibition of IL-2 secretion. However, the effects of arsenite on IL-2 mRNA expression or on the ERK pathway in activated-T cells have not yet been described. We examined the effect of arsenite on IL-2 mRNA expression, cell activation and proliferation in PHA-stimulated murine lymphocytes. Arsenite (1 and 10 microM) decreased IL-2 mRNA expression, IL-2 secretion and cell proliferation. Arsenite (10 microM) strongly inhibited ERK-phosphorylation. However, the partial inhibition (50%) of IL-2 mRNA produced by 1 microM, consistent with the effects on IL-2 secretion and cell proliferation, could not be explained by the inhibition of ERK-phosphorylation, which was not affected at this concentration. The inhibition of IL-2 mRNA expression caused by 1 microM could be associated to effects on pathways located downstream or parallel to ERK. Arsenite also decreased early activation (surface CD69+ expression) in both CD4+ and CD8+, and decreased total CD8+ count without significantly affecting CD4+, supporting that the cellular immune response mediated by cytotoxic T cells is an arsenic target. Thus, our results suggest that arsenite decreases IL-2 mRNA levels and T-cell activation and proliferation. However, further studies on the effects of arsenite on IL-2 gene transcription and IL-2 mRNA stability are needed.

  16. Alpha2-adrenoceptor-independent inhibition of acetylcholine receptor channel and sodium channel by dexmedetomidine in rat superior cervical ganglion neurons.

    PubMed

    Yang, L; Tang, J; Dong, J; Zheng, J

    2015-03-19

    Both central and peripheral sympathetic nervous systems contribute to the cardiovascular effects of dexmedetomidine (DMED), a highly selective and widely used a2-adrenoceptor agonist for sedation, analgesia, and stress management. The central sympatholytic effects are augmented by peripheral inhibition of sympathetic ganglion transmission. The mechanism is not clear. In this research, using conventional patch-clamp recordings we investigated the direct effects of DMED on sodium (Na(+)) channel currents (INa) and nicotinic acetylcholine (ACh) receptor (nAChRs) channel currents (IACh) in rat superior cervical ganglion (SCG) neurons to explore the possible mechanisms of sympathetic ganglion transmission inhibition by DMED. DMED voltage-dependently suppressed INa with half maximal inhibitory concentration (IC50) values of 67.2±9.6μM and 26.1±5.3μM at holding potentials of -80mV and -60mV, respectively. The inhibition of Na(+) channels by DMED was also frequency dependent. 100μM DMED shifted the Na(+) channel inactivation curves to the hyperpolarizing direction by 9.8mV (P<0.01) and slowed the recovery from inactivation by 8.9ms (P<0.01), but no effects were seen on the shape of the current-voltage relationship or Na(+) channels activation curves. DMED dose-dependently inhibited IACh with an IC50 value of 5.5±2.4μM in SCG neurons, and this inhibition was voltage-independent. DMED pretreatment followed by fast co-application of DMED and ACh produced a significantly larger IACh inhibition than without DMED pretreatment. Yohimbine, phentolamine, and atropine pretreatment did not alter the inhibitory effects of DMED on INa and IACh. In conclusion, DMED dose-dependently inhibits INa and IACh in rat SCG neurons by preferential binding to the inactivated state of the Na(+) channels and the closed state (resting) of nAChR channels respectively. Both inhibitions are a2-adrenoceptor independent. Furthermore, the nAChR channels in rat SCG neurons are much more sensitive to

  17. Sodium houttuyfonate inhibits biofilm formation and alginate biosynthesis-associated gene expression in a clinical strain of Pseudomonas aeruginosa in vitro

    PubMed Central

    WU, DA-QIANG; CHENG, HUIJUAN; DUAN, QIANGJUN; HUANG, WEIFENG

    2015-01-01

    The increasing multidrug resistance of Pseudomonas aeruginosa has become a serious public-health problem. In the present study, the inhibitory activities of sodium houttuyfonate (SH) against biofilm formation and alginate production in a clinical strain of P. aeruginosa (AH16) were investigated in vitro using crystal violet dying and standard curve methods, respectively. The cellular morphology of P. aeruginosa treated with SH was observed using a scanning electron microscope. Furthermore, reverse transcription-quantitative polymerase chain reaction was used to identify differences in the expression levels of genes associated with alginate biosynthesis as a result of the SH treatment. The results indicated that SH significantly inhibited biofilm formation, and decreased the levels of the primary biofilm constituent, alginate, in P. aeruginosa AH16 at various stages of biofilm development. In addition, scanning electron microscopy observations demonstrated that SH markedly altered the cellular morphology and biofilm structure of P. aeruginosa. Furthermore, the results from the reverse transcription-quantitative polymerase chain reaction analysis indicated that SH inhibited biofilm formation by mitigating the expression of the algD and algR genes, which are associated with alginate biosynthesis. Therefore, the present study has provided novel insights into the potent effects and underlying mechanisms of SH-induced inhibition of biofilm formation in a clinical strain of P. aeruginosa. PMID:26622388

  18. Sodium houttuyfonate inhibits biofilm formation and alginate biosynthesis-associated gene expression in a clinical strain of Pseudomonas aeruginosa in vitro.

    PubMed

    Wu, DA-Qiang; Cheng, Huijuan; Duan, Qiangjun; Huang, Weifeng

    2015-08-01

    The increasing multidrug resistance of Pseudomonas aeruginosa has become a serious public-health problem. In the present study, the inhibitory activities of sodium houttuyfonate (SH) against biofilm formation and alginate production in a clinical strain of P.aeruginosa (AH16) were investigated in vitro using crystal violet dying and standard curve methods, respectively. The cellular morphology of P. aeruginosa treated with SH was observed using a scanning electron microscope. Furthermore, reverse transcription-quantitative polymerase chain reaction was used to identify differences in the expression levels of genes associated with alginate biosynthesis as a result of the SH treatment. The results indicated that SH significantly inhibited biofilm formation, and decreased the levels of the primary biofilm constituent, alginate, in P. aeruginosa AH16 at various stages of biofilm development. In addition, scanning electron microscopy observations demonstrated that SH markedly altered the cellular morphology and biofilm structure of P. aeruginosa. Furthermore, the results from the reverse transcription-quantitative polymerase chain reaction analysis indicated that SH inhibited biofilm formation by mitigating the expression of the algD and algR genes, which are associated with alginate biosynthesis. Therefore, the present study has provided novel insights into the potent effects and underlying mechanisms of SH-induced inhibition of biofilm formation in a clinical strain of P. aeruginosa.

  19. Alkaline reforming of brominated fire-retardant plastics: fate of bromine and antimony.

    PubMed

    Onwudili, Jude A; Williams, Paul T

    2009-02-01

    High-impact polystyrene (HIPS) flame retarded with decabromodiphenyl ether (DDE), has been reacted in supercritical water from 380 to 450 degrees C and 21.5 to 31.0 MPa pressure in a batch reactor. Different concentrations of sodium hydroxide additive were used in situ to neutralize the corrosive inorganic bromine species released during the reactions. It appeared that supercritical water conditions lowered the decomposition temperature of both the fire-retardant DDE and HIPS. The reaction products included oils (up to 76 wt%), char (up to 18 wt%) and gas (up to 2.4 wt%) which was mainly methane. The presence of the alkaline water led to up to 97 wt% debromination of the product oil, producing virtually bromine-free oil feedstock. The removal of antimony from the oil product during processing was of the order of 98 wt%. The oil consisted of many single- and multiple-ringed aromatic compounds, many of which had alkyl substituents and/or aliphatic C(n)-bridges (n=1-4). The major single-ringed compounds included toluene, xylenes, ethylbenzene, propylbenzene and alpha-methylstyrene. Bibenzyl (diphenylethane), stilbene, diphenylmethane, diphenylpropane, diphenylcyclopropane, diphenylpropene, diphenylbutane, diphenylbutene and diphenylbuta-1,3-diene were the major C(n)-bridged compounds. Diphenyl ether and acetophenone were the major oxygenated compounds found. The process thus has the potential to produce bromine-free and antimony-free oils from fire-retardant plastics.

  20. Growth of antimony doped P-type zinc oxide nanowires for optoelectronics

    DOEpatents

    Wang, Zhong Lin; Pradel, Ken

    2016-09-27

    In a method of growing p-type nanowires, a nanowire growth solution of zinc nitrate (Zn(NO.sub.3).sub.2), hexamethylenetetramine (HMTA) and polyethylenemine (800 M.sub.w PEI) is prepared. A dopant solution to the growth solution, the dopant solution including an equal molar ration of sodium hydroxide (NaOH), glycolic acid (C.sub.2H.sub.4O.sub.3) and antimony acetate (Sb(CH.sub.3COO).sub.3) in water is prepared. The dopant solution and the growth solution combine to generate a resulting solution that includes antimony to zinc in a ratio of between 0.2% molar to 2.0% molar, the resulting solution having a top surface. An ammonia solution is added to the resulting solution. A ZnO seed layer is applied to a substrate and the substrate is placed into the top surface of the resulting solution with the ZnO seed layer facing downwardly for a predetermined time until Sb-doped ZnO nanowires having a length of at least 5 .mu.m have grown from the ZnO seed layer.

  1. Primary Biliary Acids Inhibit Hepatitis D Virus (HDV) Entry into Human Hepatoma Cells Expressing the Sodium-Taurocholate Cotransporting Polypeptide (NTCP)

    PubMed Central

    Veloso Alves Pereira, Isabel; Buchmann, Bettina; Sandmann, Lisa; Sprinzl, Kathrin; Schlaphoff, Verena; Döhner, Katinka; Vondran, Florian; Sarrazin, Christoph; Manns, Michael P.; Pinto Marques Souza de Oliveira, Cláudia; Sodeik, Beate; Ciesek, Sandra; von Hahn, Thomas

    2015-01-01

    Background The sodium-taurocholate cotransporting polypeptide (NTCP) is both a key bile acid (BA) transporter mediating uptake of BA into hepatocytes and an essential receptor for hepatitis B virus (HBV) and hepatitis D virus (HDV). In this study we aimed to characterize to what extent and through what mechanism BA affect HDV cell entry. Methods HuH-7 cells stably expressing NTCP (HuH-7/NTCP) and primary human hepatocytes (PHH) were infected with in vitro generated HDV particles. Infectivity in the absence or presence of compounds was assessed using immunofluorescence staining for HDV antigen, standard 50% tissue culture infectious dose (TCID50) assays and quantitative PCR. Results Addition of primary conjugated and unconjugated BA resulted in a dose dependent reduction in the number of infected cells while secondary, tertiary and synthetic BA had a lesser effect. This effect was observed both in HuH-7/NTCP and in PHH. Other replication cycle steps such as replication and particle assembly and release were unaffected. Moreover, inhibitory BA competed with a fragment from the large HBV envelope protein for binding to NTCP-expressing cells. Conversely, the sodium/BA-cotransporter function of NTCP seemed not to be required for HDV infection since infection was similar in the presence or absence of a sodium gradient across the plasma membrane. When chenodeoxycolic acid (15 mg per kg body weight) was administered to three chronically HDV infected individuals over a period of up to 16 days there was no change in serum HDV RNA. Conclusions Primary BA inhibit NTCP-mediated HDV entry into hepatocytes suggesting that modulation of the BA pool may affect HDV infection of hepatocytes. PMID:25646622

  2. Inhibition of cystathionine β-synthetase suppresses sodium channel activities of dorsal root ganglion neurons of rats with lumbar disc herniation

    PubMed Central

    Yan, Jun; Hu, Shufen; Zou, Kang; Xu, Min; Wang, Qianliang; Miao, Xiuhua; Yu, Shan Ping; Xu, Guang-Yin

    2016-01-01

    The pathogenesis of pain in lumbar disc herniation (LDH) remains poorly understood. We have recently demonstrated that voltage-gated sodium channels (VGSCs) in dorsal root ganglion (DRG) neurons were sensitized in a rat model of LDH. However, the detailed molecular mechanism for sensitization of VGSCs remains largely unknown. This study was designed to examine roles of the endogenous hydrogen sulfide synthesizing enzyme cystathionine β-synthetase (CBS) in sensitization of VGSCs in a previously validated rat model of LDH. Here we showed that inhibition of CBS activity by O-(Carboxymethyl) hydroxylamine hemihydrochloride (AOAA) significantly attenuated pain hypersensitivity in LDH rats. Administration of AOAA also reduced neuronal hyperexcitability, suppressed the sodium current density, and right-shifted the V1/2 of the inactivation curve, of hindpaw innervating DRG neurons, which is retrogradely labeled by DiI. In vitro incubation of AOAA did not alter the excitability of acutely isolated DRG neurons. Furthermore, CBS was colocalized with NaV1.7 and NaV1.8 in hindpaw-innervating DRG neurons. Treatment of AOAA markedly suppressed expression of NaV1.7 and NaV1.8 in DRGs of LDH rats. These data suggest that targeting the CBS-H2S signaling at the DRG level might represent a novel therapeutic strategy for chronic pain relief in patients with LDH. PMID:27905525

  3. Antioxidant activity and inhibition of aflatoxin B1-, nifuroxazide-, and sodium azide-induced mutagenicity by extracts from Rhamnus alaternus L.

    PubMed

    Ammar, Rebai Ben; Sghaier, Mohamed Ben; Boubaker, Jihed; Bhouri, Wissem; Naffeti, Aicha; Skandrani, Ines; Bouhlel, Ines; Kilani, Soumaya; Ghedira, Kamel; Chekir-Ghedira, Leila

    2008-07-10

    The effect of extracts obtained from Rhamnus alaternus L. leaves on genotoxicity and SOS response induced by aflatoxin B(1) (10 microg/assay) as well as nifuroxazide (20 microg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The evaluation of the mutagenic and antimutagenic actions of the same extracts against the sodium azide (1.5 microg/plate)-induced mutagenicity was assayed using the Salmonella typhimurium assay system. The R. alaternus tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly aqueous extract (A) and its chloroformic fraction (A(2)) significantly decreased the genotoxicity induced by aflatoxin B(1) and nifuroxazide. Moreover, the different extracts showed no mutagenicity when tested with Salmonella typhimurium strains TA1535 and TA1538 either with or without the S9 mix. Aqueous extract as well as its A(2) fraction exhibited the highest level of protection towards the direct mutagen, sodium azide-induced response in TA1535 strain with mutagenicity inhibition percentages of 83.6% and 91.4%, respectively, at a dose of 250 microg/plate. The results obtained by the Ames test assay confirm those of SOS chromotest. These same active extracts exhibited high xanthine oxidase (XOD) inhibiting with respective IC(50) values of 208 and 137 microg/ml, and superoxide anion-scavenging effects (IC(50) values of 132 and 117 microg/ml) when tested in the XOD enzymatic assay system. Our findings emphasize the potential of R. alaternus to prevent mutations and also its antioxidant effect.

  4. Astragalus polysaccharides protect against dextran sulfate sodium-induced colitis by inhibiting NF-κВ activation.

    PubMed

    Lv, Jun; Zhang, Yahong; Tian, Zhiqiang; Liu, Fang; Shi, Ying; Liu, Yao; Xia, Peiyuan

    2017-05-01

    Astragalus polysaccharide (APS) is a bioactive extract of Astragalus membranaceus (AM), which possess a wide range of medicinal benefits, including anti-inflammatory, anti-oxidative, anti-tumor and anti-diabetic effects. The present work evaluated the therapeutic effect of APS and its potential mechanisms in a mouse model of dextran sulfate sodium (DSS)-induced colitis. The APS treatment led to significant improvements in colitis disease activity index (DAI) and histological scores, as well as significantly increased weight and colon length in mice as compared to the control group. Mechanically, reduced NF-κВ DNA phosphorylation activity and downregulated TNF-α, IL-1β, IL-6, IL-17 expressions and myeloperoxidase (MPO) activity were associated with improvement in colitis observed in APS-treated mice. These findings suggest that APS may represent a natural therapeutic approach for treating inflammatory bowel disease, such as ulcerative colitis.

  5. Effect of additives on Hg2+ reduction and precipitation inhibited by sodium dithiocarbamate in simulated flue gas desulfurization solutions.

    PubMed

    Lu, Rongjie; Hou, Jiaai; Xu, Jiang; Tang, Tingmei; Xu, Xinhua

    2011-11-30

    Mercury (II) (Hg(2+)) ion can be reduced by aqueous S(IV) (sulfite and/or bisulfite) species, which leads to elemental mercury (Hg(0)) emissions in wet flue gas desulfurization (FGD) systems. Numerous reports have demonstrated the high trapping efficiency of sodium dithiocarbamate over heavy metals. In this paper, a novel sodium dithiocarbamate, DTCR, was utilized as a precipitator to control Hg(2+) reduction and Hg(0) emission against S(IV) in FGD solutions. Results indicated that Hg(2+) reduction efficiency decreased dramatically while precipitation rate peaked at around 91.0% in consistence with the increment of DTCR dosage. Initial pH and temperature had great inhibitory effects on Hg(2+) reduction: the Hg(2+) removal rate gradually increased and reached a plateau along with the increment of temperature and initial pH value. Chloride played a key role in Hg(2+) reduction and precipitation reactions. When Cl(-) concentration increased from 0 to 150 mM, Hg(2+) removal rate dropped from 93.84% to 86.05%, and the Hg(2+) reduction rate remained at a low level (<7.8%). SO(4)(2-), NO(3)(-) and other common metal ions would affect the efficiency of Hg(2+) reduction and precipitation reactions in the simulated desulfurization solutions: Hg(2+) removal rate could always be above 90%, while Hg(2+) reduction rate was maintained at below 10%. The predominance of DTCR over aqueous S(IV), indicated by the results above, has wide industrial applications in FGD systems.

  6. Mechanism of sodium uptake in PNA negative MR cells from rainbow trout, Oncorhynchus mykiss as revealed by silver and copper inhibition.

    PubMed

    Goss, Greg; Gilmour, Kathleen; Hawkings, Guy; Brumbach, Jonathan H; Huynh, Maily; Galvez, Fernando

    2011-07-01

    The rate of acid-stimulated and phenamil-sensitive sodium (Na(+)) uptake was measured in three different cell lineages: pavement cells (PVC), total mitochondrion-rich (MR) cell populations, and peanut lectin agglutinin-negative mitochondrion-rich cells (PNA(-) MR) isolated from the rainbow trout gill epithelium. Despite the presence of basal levels of Na(+) uptake in PVC, this transport was not enhanced by acidification, nor was it inhibited by independent treatment with bafilomycin (i.e., a V-type H(+)-ATPase inhibitor), phenamil (i.e., a specific inhibitor of ENaC), or Ag (a specific inhibitor of active Na(+) transport in fish). In contrast, Na(+) uptake in PNA(-) MR cells was increased by ~220% above basal levels following acidification of near 0.4 pH units in the presence of 1.0 mM external Na(+). Acid-stimulated Na(+) transport was entirely inhibited by both phenamil and bafilomycin. Silver (Ag) and copper (Cu), which are known to interfere with active Na(+) transport in fish, were also responsible for inhibiting acid stimulated Na(+) uptake in PNA(-) MR cells, but by themselves had no effect on basal Na(+) transport. Thus, we demonstrate that Ag specifically prevented acid-stimulated Na(+) uptake in PNA(-) MR cells in a dose-dependent manner. We also demonstrate rapid (<1 min) and significant inhibition of carbonic anhydrase (CA) by Ag in PNA(-) MR cells, but not in PVC. These data lend further support to the idea of a PNA(-) MR cell type as the primary site for Na(+) uptake in the freshwater (FW) gill phenotype of rainbow trout. Moreover, these findings provide support for the importance of intracellular protons in regulating the movement of Na(+) across the apical surface of the fish gill.

  7. Oroxyloside prevents dextran sulfate sodium-induced experimental colitis in mice by inhibiting NF-κB pathway through PPARγ activation.

    PubMed

    Wang, Xiaoping; Sun, Yang; Zhao, Yue; Ding, Youxiang; Zhang, Xiaobo; Kong, Lingyi; Li, Zhiyu; Guo, Qinglong; Zhao, Li

    2016-04-15

    Oroxyloside, as a metabolite of oroxylin A, may harbor various beneficial bioactivities which have rarely been reported in the previous studies. Here we established the dextran sulfate sodium (DSS)-induced experimental colitis and evaluated the anti-inflammatory effect of oroxyloside in vivo. As a result, oroxyloside attenuated DSS-induced body weight loss, colon length shortening and colonic pathological damage. Furthermore, oroxyloside inhibited inflammatory cell infiltration and decreased myeloperoxidase (MPO) and inducible nitric oxide synthase (iNOS) activities as well. The production of pro-inflammatory cytokines in serum and colon was also significantly reduced by oroxyloside. We unraveled the underlying mechanisms that oroxyloside inhibited NF-κB pathway by activating Peroxisome Proliferator-Activated Receptor γ (PPARγ) to attenuate DSS-induced colitis. Moreover, we investigated the anti-inflammatory effect and mechanisms of oroxyloside in the mouse macrophage cell line RAW264.7 and bone marrow derived macrophages (BMDM). Oroxyloside decreased several LPS-induced inflammatory cytokines, including IL-1β, IL-6 and TNF-α in RAW264.7 and BMDM. We also found that oroxyloside inhibited LPS-induced activation of NF-κB signaling pathway via activating PPARγ in RAW 264.7 and BMDM. Docking study showed that oroxyloside could bind with PPARγ. GW9662, the inhibitor of PPARγ, and PPARγ siRNA transfection blocked the effect of oroxyloside on PPARγ activation. Our study suggested that oroxyloside prevented DSS-induced colitis by inhibiting NF-κB pathway through PPARγ activation. Therefore, oroxyloside may be a promising and effective agent for inflammatory bowel disease (IBD).

  8. Ginsenoside Metabolite Compound K Promotes Recovery of Dextran Sulfate Sodium-Induced Colitis and Inhibits Inflammatory Responses by Suppressing NF-κB Activation

    PubMed Central

    Li, Juan; Zhong, Wei; Wang, Weiwei; Hu, Shaoping; Yuan, Jiahui; Zhang, Bing; Hu, Tianhui; Song, Gang

    2014-01-01

    Phytogenic compounds with anti-oxidant and anti-inflammatory properties, such as ginsenoside metabolite compound K (CK) or berberine (BBR), are currently discussed as promising complementary agents in the prevention and treatment of cancer and inflammation. The latest study showed that ginsenoside Rb1 and its metabolites could inhibit TNBS-induced colitis injury. However, the functional mechanisms of anti-inflammation effects of ginsenoside, particularly its metabolite CK are still not clear. Here, using dextran sulfate sodium (DSS)-induced colitis in mice, clinical parameters, intestinal integrity, pro-inflammatory cytokines production, and signaling pathways in colonic tissues were determined. In mild and sever colitis mice, CK and BBR (as a positive agent) alleviated colitis histopathology injury, ameliorated myeloperoxidase (MPO) activity, reduced pro-inflammatory cytokines production, such as, IL-6, IL-1β, TNF-α, and increased anti-inflammatory cytokine IL-10 production in both mice colon tissues and blood. Nevertheless, the results revealed that CK and BBR inhibited NF-κB p65 nuclear translocation, downregulated p-IκBα and upregulated IκBα, indicating that CK, as well as BBR, suppressed the activation of the NF-κB pathway in the progression of colitis with immunofluorescence, immunohistochemical and western blotting analysis. Furthermore, CK inhibited pro-inflammatory cytokines production in LPS-activated macrophages via down-regulation of NF-κB signaling pathway. Taken together, our results not only reveal that CK promotes the recovery of the progression of colitis and inhibits the inflammatory responses by suppressing NF-κB activation, but also suggest that CK downregulates intestinal inflammation through regulating the activation of macrophages and pro-inflammatory cytokines production. PMID:24504372

  9. Local-anesthetic like inhibition of the cardiac sodium channel Nav1.5 α-subunit by 5-HT3 receptor antagonists.

    PubMed

    Van't Klooster, Mariet P; Foadi, Nilufar; Hage, Axel; Stoetzer, Carsten; Wegner, Florian; Eberhardt, Mirjam; Leffler, Andreas

    2016-10-15

    5-hydroxytryptamine 3 receptor (5-HT3 receptor) antagonists are administered for prevention and therapy of nausea and vomiting. Although regarded as safe therapeutics, they can also provoke arrhythmias by prolonging the QRS interval. However, the mechanisms mediating this cardiotoxicity are poorly understood. Here we investigated effects of 5-HT3 receptor antagonists on the cardiac Na(+) channel Nav1.5. We explored the interaction of dolasetron, tropisetron, granisetron and ondansetron on the human α-subunit Nav1.5 heterologously expressed in HEK293 cells. Sodium currents were explored by means of whole-cell patch clamp recordings. All four substances inhibited the Nav1.5 in a concentration and state-dependent manner. Dolasetron displayed the lowest blocking efficacy, and tropisetron was the most potent blocker with a half maximum blocking concentration of 18µM for tonic block of inactivated channels. Tropisetron was also the most potent use-dependent inhibitor, and it also induced a strong open -channel block. Both tonic and use-dependent block by tropisetron were abbreviated on the local-anesthetic insensitive mutant Nav1.5-F1760A. Co-administration of tropisetron and the local anesthetic bupivacaine or the hypnotic propofol augmented inhibition of Nav1.5. Our data demonstrate that 5-HT3 receptor antagonists induce a local-anesthetic like inhibition of Nav1.5, and that they display different blocking efficacies. Reports on a relevant cardiotoxicity of dolasetron as opposed to other 5-HT3 receptor antagonists do not seem to correlate with a block of Nav1.5. As inhibition of Nav1.5 was enhanced by propofol and bupivacaine however, it is possible that a combined administration of Na(+) channel blockers and 5-HT3 receptor antagonists can provoke arrhythmias.

  10. Anti-diabetic and anti-obesity agent sodium tungstate enhances GCN pathway activation through Glc7p inhibition.

    PubMed

    Rodriguez-Hernandez, C J; Guinovart, J J; Murguia, J R

    2012-02-03

    Tungstate counteracts diabetes and obesity in animal models, but its molecular mechanisms remain elusive. Our Saccharomyces cerevisiae-based approach has found that tungstate alleviated the growth defect induced by nutrient stress and enhanced the activation of the GCN pathway. Tungstate relieved the sensitivity to starvation of a gcn2-507 yeast hypomorphic mutant, indicating that tungstate modulated the GCN pathway downstream of Gcn2p. Interestingly, tungstate inhibited Glc7p and PP1 phosphatase activity, both negative regulators of the GCN pathway in yeast and humans, respectively. Accordingly, overexpression of a dominant-negative Glc7p mutant in yeast mimicked tungstate effects. Therefore tungstate alleviates nutrient stress in yeast by in vivo inhibition of Glc7p. These data uncover a potential role for tungstate in the treatment of PP1 and GCN related diseases.

  11. Marked increases in mucociliary clearance produced by synergistic secretory agonists or inhibition of the epithelial sodium channel

    PubMed Central

    Joo, Nam Soo; Jeong, Jin Hyeok; Cho, Hyung-Ju; Wine, Jeffrey J.

    2016-01-01

    Mucociliary clearance (MCC) is a critical host innate defense mechanism in airways, and it is impaired in cystic fibrosis (CF) and other obstructive lung diseases. Epithelial fluid secretion and absorption modify MCC velocity (MCCV). We tested the hypotheses that inhibiting fluid absorption accelerates MCCV, whereas inhibiting fluid secretion decelerates it. In airways, ENaC is mainly responsible for fluid absorption, while anion channels, including CFTR and Ca2+-activated chloride channels mediate anion/fluid secretion. MCCV was increased by the cAMP-elevating agonists, forskolin or isoproterenol (10 μM) and by the Ca2+-elevating agonist, carbachol (0.3 μM). The CFTR-selective inhibitor, CFTRinh-172, modestly reduced MCCV-increases induced by forskolin or isoproterenol but not increases induced by carbachol. The ENaC inhibitor benzamil increased basal MCCV as well as MCCV increases produced by forskolin or carbachol. MCC velocity was most dramatically accelerated by the synergistic combination of forskolin and carbachol, which produced near-maximal clearance rates regardless of prior treatment with CFTR or ENaC inhibitors. In CF airways, where CFTR-mediated secretion (and possibly synergistic MCC) is lost, ENaC inhibition via exogenous agents may provide therapeutic benefit, as has long been proposed. PMID:27830759

  12. Laser resonance ionization spectroscopy of antimony

    NASA Astrophysics Data System (ADS)

    Li, R.; Lassen, J.; Ruczkowski, J.; Teigelhöfer, A.; Bricault, P.

    2017-02-01

    The resonant ionization laser ion source is an element selective, efficient and versatile ion source to generate radioactive ion beams at on-line mass separator facilities. For some elements with complex atomic structures and incomplete spectroscopic data, laser spectroscopic investigations are required for ionization scheme development. Laser resonance ionization spectroscopy using Ti:Sa lasers has been performed on antimony (Sb) at TRIUMF's off-line laser ion source test stand. Laser light of 230.217 nm (vacuum wavelength) as the first excitation step and light from a frequency-doubled Nd:YVO4 laser (532 nm) as the nonresonant ionization step allowed to search for suitable second excitation steps by continuous wavelength scans from 720 nm to 920 nm across the wavelength tuning range of a grating-tuned Ti:Sa laser. Upon the identification of efficient SES, the third excitation steps for resonance ionization were investigated by laser scans across Rydberg states, the ionization potential and autoionizing states. One Rydberg state and six AI states were found to be well suitable for efficient resonance ionization.

  13. [Antimony and other heavy metals in metallic kitchen ware].

    PubMed

    Ishiwata, H; Sugita, T; Yoshihira, K

    1989-01-01

    The antimony in metallic kitchen ware was determined. The content of this element in metals used for the production or repairing of utensils, containers and packaging which come in contact with foods is regulated and should be less than 5% in under the Japanese Food Sanitation Law. In eight metallic samples, antimony was detected in solder used for the production of a can for green tea and an eggbeater. The contents were 1.30% in the former and 1.90% in the latter. No antimony was detected in solder used for a cookie cutter. A sample of solder used for electric work, not for food utensils, contained 0.81% of antimony. In other metallic utensils which come in contact with food such as aluminum foil, a brass spoon, a stainless steel fork, a wire netting, and an iron rock for vegetable color stabilizing, antimony was not detected at a 0.05% detection limit. A qualitative test using rhodamine B also showed positive results in only three solder samples. Lead concentrations in solder used for the kitchen ware were from 39.3 to 51.3%. These concentrations were higher than the limit (20%) of lead content by the Law. No cadmium was detected in any samples.

  14. Phlomis mauritanica extracts reduce the xanthine oxidase activity, scavenge the superoxide anions, and inhibit the aflatoxin B1-, sodium azide-, and 4-nitrophenyldiamine-induced mutagenicity in bacteria.

    PubMed

    Limem, Ilef; Bouhlel, Ines; Bouchemi, Meriem; Kilani, Soumaya; Boubaker, Jihed; Ben-Sghaier, Mohamed; Skandrani, Ines; Behouri, Wissem; Neffati, Aicha; Ghedira, Kamel; Chekir-Ghedira, Leila

    2010-06-01

    Four extracts were prepared from the leaves of Phlomis mauritanica: lyophilized infusion, total oligomer flavonoids, methanol, and ethyl acetate extracts. The antimutagenic properties of these extracts were investigated by assessing the inhibition of the mutagenic effects of direct-acting mutagens such as sodium azide and 4-nitrophenylenediamine and indirect-acting mutagens like aflatoxin B1 (AFB1) using the Ames assay. The four extracts prepared from P. mauritanica strongly inhibit the mutagenicity induced by AFB1 in both Salmonella typhimurium TA 100 and TA 98 assay systems. Lyophilized infusion and methanol extracts at the dose of 250 microg per plate reduced AFB1 mutagenicity by 93% and 91%, respectively, in S. typhymurium strain TA 100. We examined also the antioxidant effect of these extracts by the enzymatic xanthine/xanthine oxidase assay. Result indicated that total oligomer flavonoids and ethyl acetate and methanol extracts were potent inhibitors of xanthine oxidase activity. In contrast, lyophilized infusion, total oligomer flavonoids, and methanol extracts exhibited a high degree of superoxide anion scavenging. Our findings emphasize the potential of P. mauritanica extracts to prevent mutations and oxidant effects. Furthermore, the results presented here could be an additional argument to support the use of this species as a medicinal and dietary plant.

  15. Sodium Butyrate Promotes Reassembly of Tight Junctions in Caco-2 Monolayers Involving Inhibition of MLCK/MLC2 Pathway and Phosphorylation of PKCβ2

    PubMed Central

    Miao, Wei; Wu, Xiujuan; Wang, Kang; Wang, Wenjing; Wang, Yumei; Li, Zhigang; Liu, Jingjing; Li, Li; Peng, Luying

    2016-01-01

    As a physiological small molecular product from the microbial fermentation of dietary fibers, butyrate plays an important role in maintaining intestinal health. Our previous works have proved that the effect of sodium butyrate (NaB) on the intestinal barrier function is mediated by activation of AMP-activated protein kinase (AMPK). However, the detailed pathway involved remains unknown. Using the calcium switch assay in the Caco-2 cell monolayer model, we found here that NaB activated AMPK mainly by increasing the calcium level, but not the ATP concentration, via promoting store-operated calcium entry (SOCE). Upon the activation of AMPK, NaB promoted the reassembly of tight junctions (TJs) based on reducing the phosphorylation of myosin II regulatory light chain (MLC2) at Ser19 and increasing phosphorylation of protein kinase C β2 (PKCβ2) at Ser660. Inhibiting (protein kinase C β) PKCβ blocked the reassembly of TJs induced by NaB in the barrier monolayer model. These results indicated that NaB could activate the calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) pathway to mediate AMPK phosphorylating, which then inhibited the phosphorylation of MLC2 and promoted the phosphorylation of PKCβ2, respectively, so that the downstream molecules of AMPK coordinately contributed to the reassembly of TJs in the Caco-2 barrier model. These results suggested a potential mechanism of butyrate for intestine homeostasis and protection. PMID:27735862

  16. Sodium houttuyfonate, a potential phytoanticipin derivative of antibacterial agent, inhibits bacterial attachment and pyocyanine secretion of Pseudomonas aeruginosa by attenuating flagella-mediated swimming motility.

    PubMed

    Shao, Jing; Cheng, Huijuan; Wang, Changzhong; Wu, Daqiang; Zhu, Xiaoli; Zhu, Lingling; Sun, Zhenxin

    2013-12-01

    Pseudomonas aeruginosa is a well-known clinical pathogen for its recalcitrant infection caused by biofilm formation which are initiated by flagella-mediated attachment. Sodium houttuyfonate (SH) is a natural phytoanticipin derivative of houttuynin and has anti-pathogenic effect on P. aeruginosa biofilm formation. In this paper, when using 1/2 × MIC SH, the diameter of P. aeruginosa swimming motility was sharply shortened to 36 % in 24 h incubation, and the fold changes of fliC required for swimming motility was 0.36 in 24 h cultivation, the adherence inhibition accounted for about 46 %, and the pyocyanin production decreased to 47 % after 1-day treatment and 56 % after 3-day treatment with obvious visual changes from dark green to light green, compared with the negative control. With the help of mass spectra and scanning electronic microscope, 1/2 × MIC SH was further testified to be enough to eradicate flagella and inhibit pyocyanin secretion of P. aeruginosa. The results do not only re-affirm the close interplay of attachment and virulence (i.e. swimming motility and pyocyanin), but also unravel the potential mechanism of SH on anti-biofilm of P. aeruginosa.

  17. Mitochondrial inhibitor sodium azide inhibits the reorganization of mitochondria-rich cytoplasm and the establishment of the anteroposterior axis in ascidian embryo.

    PubMed

    Ishii, Hirokazu; Shirai, Takuma; Makino, Chisato; Nishikata, Takahito

    2014-02-01

    In ascidian eggs, cytoplasmic and cortical reorganization, previously called ooplasmic segregation, occurs in two phases during the first cell cycle. In the second phase of reorganization, the mitochondria-rich cytoplasm (myoplasm) moves to the future posterior side, concurrent with sperm aster migration along the egg cortex. Although this reorganization is the critical step for establishing the anteroposterior axis, its molecular mechanism is not fully understood. In this study, we showed that low concentrations of the mitochondrial inhibitor sodium azide (NaN3 ), which showed the low toxicity in sperm, inhibited the second phase of reorganization without the microtubule depolymerization. In the NaN3 -treated embryo, the sperm aster was not attracted to the cortex and altered its migration pathway; therefore, the myoplasm remained at the vegetal pole. Consequently, the anteroposterior axis was not established. Another mitochondrial inhibitor, oligomycin, did not affect these processes. These results suggest that NaN3 inhibits unknown molecules that are important for the second phase of reorganization. Identifying the target molecule of NaN3 will lead to a molecular understanding of cytoplasmic and cortical reorganization.

  18. Adding sodium dodecyl sulfate and Pseudomonas aeruginosa UG2 biosurfactants inhibits polycyclic aromatic hydrocarbon biodegradation in a weathered creosote-contaminated soil.

    PubMed

    Deschênes, L; Lafrance, P; Villeneuve, J P; Samson, R

    1996-12-01

    The effect of two anionic surfactants was assessed during biodegradation of 13 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAH) in a wood-preserving soil contaminated with creosote and pentacholorophenol for a period of at least 20 years. Sodium dodecyl sulfate (SDS) and biosurfactants from Pseudomonas aeruginosa UG2 were utilized at concentrations of 10, 100 and 500 micrograms/g soil. Because both surfactants are readily biodegradable, the microcosms received a fresh spike of surfactant every 2 weeks. Biodegradation of aged PAH residues was monitored by GC/MS for a period of 45 weeks. Results indicated that the biodegradation of the three-ring PAH was rapid and almost complete but was slowed by the addition of 100 micrograms/g and 500 micrograms/g chemical surfactant. Similarly, at the same concentrations, the two surfactants significantly decreased the biodegradation rate of the four-ring PAH. In this case, the inhibition was more pronounced with SDS. High-molecular-mass PAH (more than four rings) were not biodegraded under the test conditions. It was suggested that the preferential utilization of surfactants by PAH degraders was responsible for the inhibition observed in the biodegradation of the hydrocarbons. The high biodegradability and the inhibitory effect of these two surfactants would have a significant impact on the development of both above-ground and in situ site reclamation processes.

  19. Tarantula Huwentoxin-IV Inhibits Neuronal Sodium Channels by Binding to Receptor Site 4 and Trapping the Domain II Voltage Sensor in the Closed Configuration*S⃞

    PubMed Central

    Xiao, Yucheng; Bingham, Jon-Paul; Zhu, Weiguo; Moczydlowski, Edward; Liang, Songping; Cummins, Theodore R.

    2008-01-01

    Peptide toxins with high affinity, divergent pharmacological functions, and isoform-specific selectivity are powerful tools for investigating the structure-function relationships of voltage-gated sodium channels (VGSCs). Although a number of interesting inhibitors have been reported from tarantula venoms, little is known about the mechanism for their interaction with VGSCs. We show that huwentoxin-IV (HWTX-IV), a 35-residue peptide from tarantula Ornithoctonus huwena venom, preferentially inhibits neuronal VGSC subtypes rNav1.2, rNav1.3, and hNav1.7 compared with muscle subtypes rNav1.4 and hNav1.5. Of the five VGSCs examined, hNav1.7 was most sensitive to HWTX-IV (IC50 ∼ 26 nm). Following application of 1 μm HWTX-IV, hNav1.7 currents could only be elicited with extreme depolarizations (>+100 mV). Recovery of hNav1.7 channels from HWTX-IV inhibition could be induced by extreme depolarizations or moderate depolarizations lasting several minutes. Site-directed mutagenesis analysis indicated that the toxin docked at neurotoxin receptor site 4 located at the extracellular S3-S4 linker of domain II. Mutations E818Q and D816N in hNav1.7 decreased toxin affinity for hNav1.7 by ∼300-fold, whereas the reverse mutations in rNav1.4 (N655D/Q657E) and the corresponding mutations in hNav1.5 (R812D/S814E) greatly increased the sensitivity of the muscle VGSCs to HWTX-IV. Our data identify a novel mechanism for sodium channel inhibition by tarantula toxins involving binding to neurotoxin receptor site 4. In contrast to scorpion β-toxins that trap the IIS4 voltage sensor in an outward configuration, we propose that HWTX-IV traps the voltage sensor of domain II in the inward, closed configuration. PMID:18628201

  20. Potassium uptake supporting plant growth in the absence of AKT1 channel activity: Inhibition by ammonium and stimulation by sodium

    NASA Technical Reports Server (NTRS)

    Spalding, E. P.; Hirsch, R. E.; Lewis, D. R.; Qi, Z.; Sussman, M. R.; Lewis, B. D.

    1999-01-01

    A transferred-DNA insertion mutant of Arabidopsis that lacks AKT1 inward-rectifying K+ channel activity in root cells was obtained previously by a reverse-genetic strategy, enabling a dissection of the K+-uptake apparatus of the root into AKT1 and non-AKT1 components. Membrane potential measurements in root cells demonstrated that the AKT1 component of the wild-type K+ permeability was between 55 and 63% when external [K+] was between 10 and 1,000 microM, and NH4+ was absent. NH4+ specifically inhibited the non-AKT1 component, apparently by competing for K+ binding sites on the transporter(s). This inhibition by NH4+ had significant consequences for akt1 plants: K+ permeability, 86Rb+ fluxes into roots, seed germination, and seedling growth rate of the mutant were each similarly inhibited by NH4+. Wild-type plants were much more resistant to NH4+. Thus, AKT1 channels conduct the K+ influx necessary for the growth of Arabidopsis embryos and seedlings in conditions that block the non-AKT1 mechanism. In contrast to the effects of NH4+, Na+ and H+ significantly stimulated the non-AKT1 portion of the K+ permeability. Stimulation of akt1 growth rate by Na+, a predicted consequence of the previous result, was observed when external [K+] was 10 microM. Collectively, these results indicate that the AKT1 channel is an important component of the K+ uptake apparatus supporting growth, even in the "high-affinity" range of K+ concentrations. In the absence of AKT1 channel activity, an NH4+-sensitive, Na+/H+-stimulated mechanism can suffice.

  1. Sodium hydrogen sulfide inhibits nicotine and lipopolysaccharide-induced osteoclastic differentiation and reversed osteoblastic differentiation in human periodontal ligament cells.

    PubMed

    Lee, Sun-Kyung; Chung, Jong-Hyuk; Choi, Sung-Chul; Auh, Q-Schick; Lee, Young-Man; Lee, Sang-Im; Kim, Eun-Cheol

    2013-05-01

    Although previous studies have demonstrated that hydrogen sulfide (H(2)S) stimulated or inhibited osteoclastic differentiation, little is known about the effects of H(2)S on the differentiation of osteoblasts and osteoclasts. To determine the possible bioactivities of H(2)S on bone metabolism, we investigated the in vitro effects of H(2)S on cytotoxicity, osteoblastic, and osteoclastic differentiation as well as the underlying mechanism in lipopolysaccharide (LPS) and nicotine-stimulated human periodontal ligament cells (hPDLCs). The H(2)S donor, NaHS, protected hPDLCs from nicotine and LPS-induced cytotoxicity and recovered nicotine- and LPS-downregulated osteoblastic differentiation, such as alkaline phosphatase (ALP) activity, mRNA expression of osteoblasts, including ALP, osteopontin (OPN), and osteocalcin (OCN), and mineralized nodule formation. Concomitantly, NaHS inhibited the differentiation of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts in mouse bone marrow cells and blocked nicotine- and LPS-induced osteoclastogenesis regulatory molecules, such as RANKL, OPG, M-CSF, MMP-9, TRAP, and cathepsin K mRNA. NaHS blocked nicotine and LPS-induced activation of p38, ERK, MKP-1, PI3K, PKC, and PKC isoenzymes, and NF-κB. The effects of H(2)S on nicotine- and LPS-induced osteoblastic and osteoclastic differentiation were remarkably reversed by MKP-1 enzyme inhibitor (vanadate) and expression inhibitor (triptolide). Taken together, we report for the first time that H(2)S inhibited cytotoxicity and osteoclastic differentiation and recovered osteoblastic differentiation in a nicotine- and periodontopathogen-stimulated hPDLCs model, which has potential therapeutic value for treatment of periodontal and inflammatory bone diseases.

  2. 40 CFR 440.90 - Applicability; description of the antimony ore subcategory.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... antimony ore subcategory. 440.90 Section 440.90 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS ORE MINING AND DRESSING POINT SOURCE CATEGORY Antimony Ore Subcategory § 440.90 Applicability; description of the antimony ore subcategory. The provisions of...

  3. Growth inhibition of human melanoma tumor cells by the combination of sodium phenylacetate (NaPA) and substituted dextrans and one NaPA-dextran conjugate.

    PubMed

    Gervelas, C; Avramoglou, T; Crépin, M; Jozefonvicz, J

    2002-01-01

    We have studied the cytostatic effects of sodium phenylacetate (NaPA) in association with several substituted dextrans on human tumor melanoma 1205LU cells. We show that NaPA alone inhibits the growth of these cells (IC50 = 3.9 mM) while a weak inhibitory effect appears at a concentration of 37 microM (10 microg/ml) for a dextran methyl carboxylate benzylamide (LS17-DMCB). The precursors of LS17-DMCB [T40 Dextran and carboxymethyl dextran (LS17-DMC)] did not affect the growth of 1205LU cells. To potentiate the inhibitory activity of NaPA at low concentrations (below 5.6 mM), we have tested NaPA and LS17-DMCB in physical mixture (association) or linked together covalently (this conjugate is termed 'LS17-NaPaC'). We have observed an increase of the 1205LU cell growth inhibition effect with NaPA in association (IC50 1.8 mM). For a concentration of 5 mM of NaPA (free in the case of association or linked in the case of conjugate), the association with dextran derivative exhibits a 4.6-fold higher efficacy than with NaPA alone (9 versus 41% surviving fraction), while the conjugate is 1.3-fold smaller (52% growth inhibition). By performing isobologram analysis of the IC50 data, we have shown a synergistic effect for a particular molar ratio of NaPA and LS17-DMCB (NaPA:LS17-DMCB = 0.35).

  4. Co-culture with human synovium-derived mesenchymal stem cells inhibits inflammatory activity and increases cell proliferation of sodium nitroprusside-stimulated chondrocytes

    SciTech Connect

    Ryu, Jae-Sung; Jung, Yeon-Hwa; Cho, Mi-Young; Yeo, Jee Eun; Choi, Yun-Jin; Kim, Yong Il; Koh, Yong-Gon

    2014-05-16

    Highlights: • Co-culture of hSDMSCs with SNP-stimulated chondrocytes improves anti-inflammation. • Co-culture system produces IGF-1. • Co-culture system suppresses inflammatory genes expression. • Co-culture system improves cell proliferation. • Exogenous IGF-1 inhibits inflammatory activity in SNP-stimulated chondrocytes. - Abstract: Rheumatoid arthritis (RA) and osteoarthritis (OA) are primarily chronic inflammatory diseases. Mesenchymal stem cells (MSCs) have the ability to differentiate into cells of the mesodermal lineage, and to regulate immunomodulatory activity. Specifically, MSCs have been shown to secrete insulin-like growth factor 1 (IGF-1). The purpose of the present study was to examine the inhibitory effects on inflammatory activity from a co-culture of human synovium-derived mesenchymal stem cells (hSDMSCs) and sodium nitroprusside (SNP)-stimulated chondrocytes. First, chondrocytes were treated with SNP to generate an in vitro model of RA or OA. Next, the co-culture of hSDMSCs with SNP-stimulated chondrocytes reduced inflammatory cytokine secretion, inhibited expression of inflammation activity-related genes, generated IGF-1 secretion, and increased the chondrocyte proliferation rate. To evaluate the effect of IGF-1 on inhibition of inflammation, chondrocytes pre-treated with IGF-1 were treated with SNP, and then the production of inflammatory cytokines was analyzed. Treatment with IGF-1 was shown to significantly reduce inflammatory cytokine secretion in SNP-stimulated chondrocytes. Our results suggest that hSDMSCs offer a new strategy to promote cell-based cartilage regeneration in RA or OA.

  5. Molecular basis of the inhibition of the fast inactivation of voltage-gated sodium channel Nav1.5 by tarantula toxin Jingzhaotoxin-II.

    PubMed

    Huang, Ying; Zhou, Xi; Tang, Cheng; Zhang, Yunxiao; Tao, Huai; Chen, Ping; Liu, Zhonghua

    2015-06-01

    Jingzhaotoxin-II (JZTX-II) is a 32-residue peptide from the Chinese tarantula Chilobrachys jingzhao venom, and preferentially inhibits the fast inactivation of the voltage-gated sodium channels (VGSCs) in rat cardiac myocytes. In the present study, we elucidated the action mechanism of JZTX-II inhibiting hNav1.5, a VGSC subtype mainly distributed in human cardiac myocytes. Among the four VGSC subtypes tested, hNav1.5 was the most sensitive to JZTX-II (EC50=125±4nM). Although JZTX-II had little or no effect on steady-state inactivation of the residual currents conducted by hNav1.5, it caused a 10mV hyperpolarized shift of activation. Moreover, JZTX-II increased the recovery rate of hNav1.5 channels, which should lead to a shorter transition from the inactivation to closed state. JZTX-II dissociated from toxin-channel complex via extreme depolarization and subsequently rebound to the channel upon repolarization. Mutagenesis analyses showed that the domain IV (DIV) voltage-sensor domain (VSD) was critical for JZTX-II binding to hNav1.5 and some mutations located in S1-S2 and S3-S4 extracellular loops of hNav1.5 DIV additively reduced the toxin sensitivity of hNav1.5. Our data identified the mechanism underlying JZTX-II inhibiting hNav1.5, similar to scorpion α-toxins, involving binding to neurotoxin receptor site 3.

  6. Inhibition by sodium cromoglycate of bronchoconstriction stimulated by respiratory heat loss: comparison of pressurised aerosol and powder.

    PubMed Central

    Latimer, K M; Roberts, R; Morris, M M; Hargreave, F E

    1984-01-01

    The protective effect was examined of three doses (2, 10, and 20 mg) of sodium cromoglycate inhaled from a pressurised metered dose inhaler on the response to isocapnic hyperventilation of cold dry air in 10 asthmatic subjects. This was compared with the effect of cromoglycate powder (20 mg) inhaled from a Spincap and with placebo given on two occasions. The medications were inhaled on separate days, in random order and with the use of a double blind double dummy technique, 20 minutes before isocapnic hyperventilation of two fold increasing volumes of air (-15 degrees C, 0% humidity) to produce a 20% fall in the post-treatment FEV1. The response was expressed as the provocative dose of respiratory heat loss required to cause a fall in FEV1 of 15% (PD15, kcal/min). The mean baseline spirometric indices exceeded 85% of predicted normal values on each test day; both placebo treatments reduced the baseline FEV1 by comparison with all active treatments (p less than 0.0001). Comparison of the PD15 on the two placebo days confirmed excellent reproducibility. All doses of cromoglycate shifted the respiratory heat loss dose-response curve to the right of the placebo curve; PD15 after all active treatments exceeded PD15 after placebo (p less than 0.0001). There was no cromoglycate dose-response relationship between the three doses of aerosol (p greater than 0.05), or between any dose of aerosol and powder (p greater than 0.05). It is concluded that cromoglycate aerosol inhaled from a pressurised inhaler in a dose of 2 mg gives the same magnitude of protection against bronchoconstriction stimulated by airway cooling as 20 mg of pressurised aerosol or powder from a Spincap. PMID:6426073

  7. [Astaxanthin inhibits sodium azide-induced cytotoxicity in hepatocyte L-02 cells probably by H+ transferring function].

    PubMed

    Ma, Jian; Chen, Hai-min; Yan, Xiao-jun; Wang, Feng; Xu, Wei-feng

    2011-05-01

    This study is to investigate the protective effect of astaxanthin against injured hepatocyte L-02 cells induced by sodium azide (NaN3) and reveal the possible mechanisms. Hepatocyte L-02 cells were exposed to 100 mmol.L-1 NaN3 with various concentrations of astaxanthin pre-incubated, then the cell viability was measured by MTT method; The level of reactive oxygen species (ROS) was determined by DCFH-DA method; The changes of mitochondrial membrane potential (MMP) and apoptosis ratio were detected by JC-1 method and Annexin V-FITC/PI double stain method, respectively. Results showed that after cells were exposed to 100 mmol.L-1 NaN3 for 3 hours, the cell viability significantly decreased; ROS level and the percentage of late phase apoptosis increased obviously; MMP was also declined. When cells were pretreated with astaxanthin, the cell damage and late phase apoptosis ratio reduced and MMP was maintained. However, the level of ROS showed insignificant decrease (P>0.05). The beneficial concentration of astaxanthin in improving cell viability and MMP was not in a dose dependent manner and the most effective of which was 0.10 nmol.L-1 (P<0.01). In order to reveal its possible non-antioxidant mechanism, mitochondrial membrane was imitated and H+ transferring function of astaxanthin was also detected by bilayer lipid membrane (BLM) method. Results showed that 2.0% astaxanthin could transfer H+ efficiently. These suggested the mechanisms of astaxanthin in protection of hepatocyte L-02 cells not via its ROS quenching capability but via its H+ transferring function, which improved the mitochondrial function and had the sequence biology effects.

  8. Structural Basis for the Inhibition of Voltage-gated Sodium Channels by Conotoxin μO§-GVIIJ*

    PubMed Central

    Green, Brad R.; Gajewiak, Joanna; Chhabra, Sandeep; Skalicky, Jack J.; Zhang, Min-Min; Rivier, Jean E.; Bulaj, Grzegorz; Yoshikami, Doju

    2016-01-01

    Cone snail toxins are well known blockers of voltage-gated sodium channels, a property that is of broad interest in biology and therapeutically in treating neuropathic pain and neurological disorders. Although most conotoxin channel blockers function by direct binding to a channel and disrupting its normal ion movement, conotoxin μO§-GVIIJ channel blocking is unique, using both favorable binding interactions with the channel and a direct tether via an intermolecular disulfide bond. Disulfide exchange is possible because conotoxin μO§-GVIIJ contains an S-cysteinylated Cys-24 residue that is capable of exchanging with a free cysteine thiol on the channel surface. Here, we present the solution structure of an analog of μO§-GVIIJ (GVIIJ[C24S]) and the results of structure-activity studies with synthetic μO§-GVIIJ variants. GVIIJ[C24S] adopts an inhibitor cystine knot structure, with two antiparallel β-strands stabilized by three disulfide bridges. The loop region linking the β-strands (loop 4) presents residue 24 in a configuration where it could bind to the proposed free cysteine of the channel (Cys-910, rat NaV1.2 numbering; at site 8). The structure-activity study shows that three residues (Lys-12, Arg-14, and Tyr-16) located in loop 2 and spatially close to residue 24 were also important for functional activity. We propose that the interaction of μO§-GVIIJ with the channel depends on not only disulfide tethering via Cys-24 to a free cysteine at site 8 on the channel but also the participation of key residues of μO§-GVIIJ on a distinct surface of the peptide. PMID:26817840

  9. Structural Basis for the Inhibition of Voltage-gated Sodium Channels by Conotoxin μO§-GVIIJ.

    PubMed

    Green, Brad R; Gajewiak, Joanna; Chhabra, Sandeep; Skalicky, Jack J; Zhang, Min-Min; Rivier, Jean E; Bulaj, Grzegorz; Olivera, Baldomero M; Yoshikami, Doju; Norton, Raymond S

    2016-03-25

    Cone snail toxins are well known blockers of voltage-gated sodium channels, a property that is of broad interest in biology and therapeutically in treating neuropathic pain and neurological disorders. Although most conotoxin channel blockers function by direct binding to a channel and disrupting its normal ion movement, conotoxin μO§-GVIIJ channel blocking is unique, using both favorable binding interactions with the channel and a direct tether via an intermolecular disulfide bond. Disulfide exchange is possible because conotoxin μO§-GVIIJ contains anS-cysteinylated Cys-24 residue that is capable of exchanging with a free cysteine thiol on the channel surface. Here, we present the solution structure of an analog of μO§-GVIIJ (GVIIJ[C24S]) and the results of structure-activity studies with synthetic μO§-GVIIJ variants. GVIIJ[C24S] adopts an inhibitor cystine knot structure, with two antiparallel β-strands stabilized by three disulfide bridges. The loop region linking the β-strands (loop 4) presents residue 24 in a configuration where it could bind to the proposed free cysteine of the channel (Cys-910, rat NaV1.2 numbering; at site 8). The structure-activity study shows that three residues (Lys-12, Arg-14, and Tyr-16) located in loop 2 and spatially close to residue 24 were also important for functional activity. We propose that the interaction of μO§-GVIIJ with the channel depends on not only disulfide tethering via Cys-24 to a free cysteine at site 8 on the channel but also the participation of key residues of μO§-GVIIJ on a distinct surface of the peptide.

  10. Possible Links between Sickle Cell Crisis and Pentavalent Antimony

    PubMed Central

    Garcerant, Daniel; Rubiano, Luisa; Blanco, Victor; Martinez, Javier; Baker, Nancy C.; Craft, Noah

    2012-01-01

    For over 60 years, pentavalent antimony (Sbv) has been the first-line treatment of leishmaniasis. Sickle cell anemia is a disease caused by a defect in red blood cells, which among other things can cause vasooclusive crisis. We report the case of a 6-year-old child with leishmaniasis who during treatment with meglumine antimoniate developed a sickle cell crisis (SCC). No previous reports describing the relationship between antimonial drugs and sickle cell disease were found. Reviews of both the pathophysiology of SCC and the mechanism of action of Sbv revealed that a common pathway (glutathione) may have resulted in the SCC. ChemoText, a novel database created to predict chemical-protein-disease interactions, was used to perform a more expansive and systematic review that was able to support the association between glutathione, Sbv, and SCC. Although suggestive evidence to support the hypothesis, additional research at the bench would be needed to prove Sbv caused the SCC. PMID:22665619

  11. Antimony Based III-V Thermophotovoltaic Devices

    SciTech Connect

    CA Wang

    2004-06-09

    Antimony-based III-V thermophotovoltaic (TPV) cells are attractive converters for systems with low radiator temperature around 1100 to 1700 K, since these cells potentially can be spectrally matched to the thermal source. Cells under development include GaSb and the lattice-matched GaInAsSb/GaSb and InPAsSb/InAs quaternary systems. GaSb cell technology is the most mature, owing in part to the relative ease in preparation of the binary alloy compared to quaternary GaInAsSb and InPAsSb alloys. Device performance of 0.7-eV GaSb cells exceeds 90% of the practical limit. GaInAsSb TPV cells have been the primary focus of recent research, and cells with energy gap E{sub g} ranging from {approx}0.6 to 0.49 eV have been demonstrated. Quantum efficiency and fill factor approach theoretical limits. Open-circuit voltage factor is as high as 87% of the practical limit for the higher-E{sub g} cells, but degrades to below 80% with decreasing E{sub g} of the alloy, which might be due to Auger recombination. InPAsSb cells are the least studied, and a cell with E{sub g} = 0.45-eV has extended spectral response out to 4.3 {micro}m. This paper briefly reviews the main contributions that have been made for antimonide-based TPV cells, and suggests additional studies for further performance enhancements.

  12. Antimony recycling in the United States in 2000

    USGS Publications Warehouse

    Carlin Jr., James F.

    2006-01-01

    The importance of recycling has become more obvious as concerns about the environment and import dependence have grown in recent years. When materials are recycled, fewer natural resources are consumed, and less waste products go to landfills or pollute the water and air. This study, one of a series of reports on metals recycling in 2000, discusses the flow of antimony from mining through its uses and disposal with emphasis on recycling. In 2000, the recycling efficiency for antimony was estimated to be 89 percent, and the recycling rate was about 20 percent.

  13. Sodium orthovanadate associated with pharmacological doses of ascorbate causes an increased generation of ROS in tumor cells that inhibits proliferation and triggers apoptosis

    SciTech Connect

    Günther, T-hat nia Mara Fischer; Kviecinski, Maicon Roberto; Baron, Carla Cristine; Felipe, Karina Bettega; Farias, Mirelle Sifroni; Ourique da Silva, Fabiana; Bücker, Nádia Cristina Falcão; Pich, Claus Tröger; Ferreira, Eduardo Antonio; Filho, Danilo Wilhelm; Verrax, Julien; Calderon, Pedro Buc; Pedrosa, Rozangela Curi

    2013-01-18

    Graphical abstract: -- Abstract: Pharmacological doses of ascorbate were evaluated for its ability to potentiate the toxicity of sodium orthovanadate (Na{sub 3}VO{sub 4}) in tumor cells. Cytotoxicity, inhibition of cell proliferation, generation of ROS and DNA fragmentation were assessed in T24 cells. Na{sub 3}VO{sub 4} was cytotoxic against T24 cells (EC{sub 50} = 5.8 μM at 24 h), but in the presence of ascorbate (100 μM) the EC{sub 50} fell to 3.3 μM. Na{sub 3}VO{sub 4} plus ascorbate caused a strong inhibition of cell proliferation (up to 20%) and increased the generation of ROS (4-fold). Na{sub 3}VO{sub 4} did not directly cleave plasmid DNA, at this aspect no synergism was found occurring between Na{sub 3}VO{sub 4} and ascorbate once the resulting action of the combination was no greater than that of both substances administered separately. Cells from Ehrlich ascites carcinoma-bearing mice were used to determine the activity of antioxidant enzymes, the extent of the oxidative damage and the type of cell death. Na{sub 3}VO{sub 4} alone, or combined with ascorbate, increased catalase activity, but only Na{sub 3}VO{sub 4} plus ascorbate increased superoxide dismutase activity (up to 4-fold). Oxidative damage on proteins and lipids was higher due to the treatment done with Na{sub 3}VO{sub 4} plus ascorbate (2–3-fold). Ascorbate potentiated apoptosis in tumor cells from mice treated with Na{sub 3}VO{sub 4}. The results indicate that pharmacological doses of ascorbate enhance the generation of ROS induced by Na{sub 3}VO{sub 4} in tumor cells causing inhibition of proliferation and apoptosis. Apoptosis induced by orthovanadate and ascorbate is closer related to inhibition on Bcl-xL and activation of Bax. Our data apparently rule out a mechanism of cell demise p53-dependent or related to Cdk2 impairment.

  14. Ziram and sodium N,N-dimethyldithiocarbamate inhibit ubiquitin activation through intracellular metal transport and increased oxidative stress in HEK293 cells.

    PubMed

    Dennis, Kathleen E; Valentine, William M

    2015-04-20

    Ubiquitin activating enzyme E1 plays a pivotal role in ubiquitin based protein signaling through regulating the initiating step of the cascade. Previous studies demonstrated that E1 is inhibited by covalent modification of reactive cysteines contained within the ubiquitin-binding groove and by conditions that increase oxidative stress and deplete cellular antioxidants. In this study, we determined the relative contribution of covalent adduction and oxidative stress to E1 inhibition produced by ziram and sodium N,N-dimethyldithiocarbamate (DMDC) in HEK293 cells. Although no dithiocarbamate-derived E1 adducts were identified on E1 using shotgun LC/MS/MS for either ziram or DMDC, both dithiocarbamates significantly decreased E1 activity, with ziram demonstrating greater potency. Ziram increased intracellular levels of zinc and copper, DMDC increased intracellular levels of only copper, and both dithiocarbamates enhanced oxidative injury evidenced by elevated levels of protein carbonyls and expression of heme oxygenase-1. To assess the contribution of intracellular copper transport to E1 inhibition, coincubations were performed with the copper chelator triethylenetetramine hydrochloride (TET). TET significantly protected E1 activity for both of the dithiocarbamates and decreased the associated oxidative injury in HEK293 cells as well as prevented dithiocarbamate-mediated lipid peroxidation assayed using an ethyl aracidonate micelle system. Because TET did not completely ameliorate intracellular transport of copper or zinc for ziram, TET apparently maintained E1 activity through its ability to diminish dithiocarbamate-mediated oxidative stress. Experiments to determine the relative contribution of elevated intracellular zinc and copper were performed using a metal free incubation system and showed that increases in either metal were sufficient to inhibit E1. To evaluate the utility of the HEK293 in vitro system for screening environmental agents, a series of additional

  15. An improved method for the determination of trace levels of arsenic and antimony in geological materials by automated hydride generation-atomic absorption spectroscopy

    USGS Publications Warehouse

    Crock, J.G.; Lichte, F.E.

    1982-01-01

    An improved, automated method for the determination of arsenic and antimony in geological materials is described. After digestion of the material in sulfuric, nitric, hydrofluoric and perchloric acids, a hydrochloric acid solution of the sample is automatically mixed with reducing agents, acidified with additional hydrochloric acid, and treated with a sodium tetrahydroborate solution to form arsine and stibine. The hydrides are decomposed in a heated quartz tube in the optical path of an atomic absorption spectrometer. The absorbance peak height for arsenic or antimony is measured. Interferences that exist are minimized to the point where most geological materials including coals, soils, coal ashes, rocks and sediments can be analyzed directly without use of standard additions. The relative standard deviation of the digestion and the instrumental procedure is less than 2% at the 50 ??g l-1 As or Sb level. The reagent-blank detection limit is 0.2 ??g l-1 As or Sb. ?? 1982.

  16. Enhanced expression of epithelial sodium channels causes salt-induced hypertension in mice through inhibition of the α2-isoform of Na+, K+-ATPase.

    PubMed

    Leenen, Frans H H; Hou, Xiaohong; Wang, Hong-Wei; Ahmad, Monir

    2015-05-01

    Knockout of the Nedd4-2 gene in mice results in overexpression of epithelial sodium channels (ENaC) on the plasma membrane in the kidney, choroid plexus and brain nuclei. These mice exhibit enhanced pressor responses to CSF [Na(+)] as well as dietary salt-induced hypertension which both can be blocked by central infusion of the ENaC blocker benzamil. Functional studies suggest that ENaC activation in the CNS results in release of endogenous ouabain (EO) and inhibition of the α2-isoform of Na(+), K(+)-ATPase. To test this concept more specifically, we studied Nedd4-2(-/-) mice expressing the ouabain-resistant α2R/R-isoform of Na(+), K(+)-ATPase. Intracerebroventricular (icv) infusion of Na(+)-rich aCSF (225 mmol/L Na(+) at 0.4 μL/min) increased MAP by 10-15 mmHg in wild-type mice and by 25-30 mmHg in Nedd4-2(-/-) mice, but by only ~5 mmHg in α2R/R and in α2R/R/Nedd4-2(-/-) mice. Icv infusion of EO-binding Fab fragments also blocked the BP response in Nedd4-2(-/-) mice. In Nedd4-2(-/-) mice, 8% high-salt diet increased MAP by 25-30 mmHg, but in α2R/R/Nedd4-2(-/-) mice, it increased by only 5-10 mmHg. In contrast, Nedd4-2(-/-) or α2R/R did not affect the hypertension caused by sc infusion of Ang II. These findings substantiate the concept that enhanced ENaC activity causes salt-induced pressor responses mainly through EO inhibiting the α2-isoform of Na(+), K(+)-ATPase in the brain.

  17. Abciximab does not inhibit the increase of thrombin generation produced in platelet-rich plasma in vitro by sodium arachidonate or tissue factor.

    PubMed

    Altman, Raul; Scazziota, Alejandra; Santoro, Silvina; Gonzalez, Claudio

    2005-07-01

    Aspirin and platelet membrane glycoprotein (GP) IIb/IIIa blockers are currently used for acute coronary events, and in percutaneous coronary intervention for preventing further coronary outcomes, because they inhibit platelet function. Aspirin also inhibits thrombin generation (TG) in platelet-rich plasma (PRP) activated by sodium arachidonate (AA). The effect of the platelet membrane GP IIb-IIIa (integrin alpha(IIb)beta(3)) blocker abciximab on thrombin generation was studied in vitro using PRP. Thirty healthy volunteers taking no medication, and 28 volunteers who had taken aspirin (160 mg/day for 3-4 days), were included in the protocol. Control or in vivo aspirinated PRP, stimulated or not by AA or tissue factor (TF), was investigated for the inhibitory effect of abciximab pre-incubated for 3 minutes. AA and TF added in vitro activated non-aspirinated PRP: lag-time (LT) and time to peak (TTP) were significantly shortened. Peak TG (PTG) and endogenous thrombin potential (ETG) were increased by AA but not TF; thus, AA seems to be more efficient than TF for TG in this system. Abciximab added in vitro to non-activated, non-aspirinated PRP had no effect on LT, TTP, or ETP, but caused a decrease in PTG that was not statistically significant. Abciximab (3 or 4 microg/mL) added in vitro to AA or TF-activated, non-aspirinated PRP produced no effect on TG, although in aspirinated platelets both LT and time to peak were prolonged. AA as well as TF added in vitro to PRP or in vivo aspirinated PRP increased TG, although AA seems to be more efficient in our assay system. Abciximab, which affects non-aspirinated, nonactivated PRP weakly, has no effect on AA or TF in activated control PRP or in vivo aspirinated PRP.

  18. Sodium cromoglycate inhibits absorption of the major soybean allergen, Gly m Bd 30K, in mice and human intestinal Caco-2 cells.

    PubMed

    Weangsripanaval, Thanakorn; Murota, Kaeko; Murakami, Yoko; Kominami, Masaru; Kusudo, Tatsuya; Moriyama, Tatsuya; Ogawa, Tadashi; Kawada, Teruo

    2006-11-01

    Our previous data showed that Gly m Bd 30K was absorbed from the gastrointestinal tract and circulated in blood in mice. This study was conducted to determine the mechanism and identify the inhibitor of such absorption. Using sandwich ELISA and immunoblotting, we found that intact Gly m Bd 30K was absorbed from apical to basolateral solutions and intracellularly accumulated by Caco-2 cells in a dose- and time-dependent manner. The absorption and intracellular accumulation of Gly m Bd 30K were significantly suppressed when Caco-2 cells were treated with sodium cromoglycate (SCG) (0-50 mmol/L) in a dose-dependent manner. In 24-d-old mice orally treated with SCG (10-1000 mg/kg body weight), plasma Gly m Bd 30K concentration decreased significantly 30-120 min after Gly m Bd 30K (2000 mg/kg body weight) administration. Moreover, inhibitors that suppress the clathrin-dependent endocytosis dansylcadaverine, the caveolae-dependent endocytosis nystatin and clathrin, and the caveolae-dependent endocytosis methyl-beta-cyclodextrin had inhibitory effects on the absorption and intracellular accumulation of Gly m Bd 30K by Caco-2 cells. These data indicate that Gly m Bd 30K is absorbed and intracellularly accumulated in Caco-2 cells via clathrin- or caveolae-dependent endocytosis. We propose that the absorption and intracellular accumulation of Gly m Bd 30K are inhibited by SCG via clathrin- or caveolae-dependent endocytosis.

  19. Selenium-Containing Phycocyanin from Se-Enriched Spirulina platensis Reduces Inflammation in Dextran Sulfate Sodium-Induced Colitis by Inhibiting NF-κB Activation.

    PubMed

    Zhu, Chenghui; Ling, Qinjie; Cai, Zhihui; Wang, Yun; Zhang, Yibo; Hoffmann, Peter R; Zheng, Wenjie; Zhou, Tianhong; Huang, Zhi

    2016-06-22

    Selenium (Se) plays an important role in fine-tuning immune responses. Inflammatory bowel disease (IBD) involves hyperresponsive immunity of the digestive tract, and a low Se level might aggravate IBD progression; however, the beneficial effects of natural Se-enriched diets on IBD remain unknown. Previously, we developed high-yield Se-enriched Spirulina platensis (Se-SP) as an excellent organic nutritional Se source. Here we prepared Se-containing phycocyanin (Se-PC) from Se-SP and observed that Se-PC administration effectively reduced the extent of colitis in mouse induced by dextran sulfate sodium. Supplementation with Se-PC resulted in significant protective effects, including mitigation of body weight loss, bloody diarrhea, and colonic inflammatory damage. The anti-inflammatory effects of Se-PC supplementation were found to involve modulation of cytokines, including IL-6, TNF-α, MCP-1, and IL-10. Mechanistically, Se-PC inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which is involved in the transcription of these pro-inflammatory cytokines. These results together suggest potential benefits of Se-PC as a functional Se supplement to reduce the symptoms of IBD.

  20. Rosmarinic acid suppresses colonic inflammation in dextran sulphate sodium (DSS)-induced mice via dual inhibition of NF-κB and STAT3 activation

    PubMed Central

    Jin, Bo-Ram; Chung, Kyung-Sook; Cheon, Se-Yun; Lee, Minho; Hwang, Soonjae; Noh Hwang, Sam; Rhee, Ki-Jong; An, Hyo-Jin

    2017-01-01

    Ulcerative colitis (UC), a type of inflammatory bowel disease (IBD), is a chronic inflammatory disorder of the colon. Although UC is generally treated with anti-inflammatory drugs or immunosuppressants, most of these treatments often prove to be inadequate. Rosmarinic acid (RA) is a phenolic ester included in various medicinal herbs such as Salvia miltiorrhiz and Perilla frutescens. Although RA has many biological and pharmacological activities, the anti-inflammatory effect of RA in colonic tissue remains unclear. In this study, we investigated the anti-inflammatory effects and underlying molecular mechanism of RA in mice with dextran sulphate sodium (DSS)-induced colitis. In the DSS-induced colitis model, RA significantly reduced the severity of colitis, as assessed by disease activity index (DAI) scores, colonic damage, and colon length. In addition, RA resulted in the reduction of the inflammatory-related cytokines, such as IL-6, IL-1β, and IL-22, and protein levels of COX-2 and iNOS in mice with DSS-induced colitis. Furthermore, RA effectively and pleiotropically inhibited nuclear factor-kappa B and signal transducer and activator of transcription 3 activation, and subsequently reduced the activity of pro-survival genes that depend on these transcription factors. These results demonstrate that RA has an ameliorative effect on colonic inflammation and thus a potential therapeutic role in colitis. PMID:28383063

  1. Antagonistic role of tea against sodium arsenite-induced oxidative DNA damage and inhibition of DNA repair in Swiss albino mice.

    PubMed

    Sinha, Dona; Roy, Madhumita

    2011-01-01

    Arsenic (As) contamination in groundwater is of increasing health concern in West Bengal, India. Arsenic has been associated with various human cancers, but the precise mechanism of its co-carcinogenic action is not clearly elucidated. Oxidative stress and defective repair mechanisms may promote accumulation of mutations and may be a stepping stone for carcinogenesis. Prevention of arsenic-induced oxidative stress and repair inhibition may reduce the chances of initiation of cancer. Tea polyphenols are reported to have excellent chemopreventive properties against cancer. This study aimed to elucidate the role of tea against arsenic-induced formation of 8-hydroxy-2'-deoxyguanosine (8OHdG) and arsenic-suppressed DNA repair in Swiss albino mice. Both green and black tea gave fruitful results in the reduction of 8OHdG and 8-oxoguanine DNA glycosylase (OGG1) in Swiss albino mice administered sodium arsenite (As III). DNA repair enzymes--such as PARP1, DNA β-polymerase, XRCC1, DNA ligase III, DNA protein kinase (catalytic subunit), XRCC 4, DNA ligase IV, and DNA topoisomerase IIβ--were induced by the phytochemicals at both the protein and genetic levels. Thus, tea polyphenols may prove effective in treating arsenic-induced carcinogenesis.

  2. Inhibition of the sodium-translocating NADH-ubiquinone oxidoreductase [Na+-NQR] decreases cholera toxin production in Vibrio cholerae O1 at the late exponential growth phase.

    PubMed

    Minato, Yusuke; Fassio, Sara R; Reddekopp, Rylan L; Häse, Claudia C

    2014-01-01

    Two virulence factors produced by Vibrio cholerae, cholera toxin (CT) and toxin-corregulated pilus (TCP), are indispensable for cholera infection. ToxT is the central regulatory protein involved in activation of CT and TCP expression. We previously reported that lack of a respiration-linked sodium-translocating NADH-ubiquinone oxidoreductase (Na(+)-NQR) significantly increases toxT transcription. In this study, we further characterized this link and found that Na(+)-NQR affects toxT expression only at the early-log growth phase, whereas lack of Na(+)-NQR decreases CT production after the mid-log growth phase. Such decreased CT production was independent of toxT and ctxB transcription. Supplementing a respiratory substrate, l-lactate, into the growth media restored CT production in the nqrA-F mutant, suggesting that decreased CT production in the Na(+)-NQR mutant is dependent on electron transport chain (ETC) activity. This notion was supported by the observations that two chemical inhibitors, a Na(+)-NQR specific inhibitor 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO) and a succinate dehydrogenase (SDH) inhibitor, thenoyltrifluoroacetone (TTFA), strongly inhibited CT production in both classical and El Tor biotype strains of V. cholerae. Accordingly, we propose the main respiratory enzyme of V. cholerae, as a potential drug target to treat cholera because human mitochondria do not contain Na(+)-NQR orthologs.

  3. Antimony to Cure Visceral Leishmaniasis Unresponsive to Liposomal Amphotericin B.

    PubMed

    Morizot, Gloria; Jouffroy, Romain; Faye, Albert; Chabert, Paul; Belhouari, Katia; Calin, Ruxandra; Charlier, Caroline; Miailhes, Patrick; Siriez, Jean-Yves; Mouri, Oussama; Yera, Hélène; Gilquin, Jacques; Tubiana, Roland; Lanternier, Fanny; Mamzer, Marie-France; Legendre, Christophe; Peyramond, Dominique; Caumes, Eric; Lortholary, Olivier; Buffet, Pierre

    2016-01-01

    We report on 4 patients (1 immunocompetent, 3 immunosuppressed) in whom visceral leishmaniasis had become unresponsive to (or had relapsed after) treatment with appropriate doses of liposomal amphotericin B. Under close follow-up, full courses of pentavalent antimony were administered without life-threatening adverse events and resulted in rapid and sustained clinical and parasitological cure.

  4. Acid-base properties of titanium-antimony oxides catalysts

    SciTech Connect

    Zenkovets, G.A.; Paukshtis, E.A.; Tarasova, D.V.; Yurchenko, E.N.

    1982-06-01

    The acid-base properties of titanium-antimony oxide catalysts were studied by the methods of back titration and ir spectroscopy. The interrelationship between the acid-base and catalytic properties in the oxidative ammonolysis of propylene was discussed. 3 figures, 1 table.

  5. Antimony(V) Adsorption by Variable-Charge Minerals

    DTIC Science & Technology

    2013-10-01

    Sb(OH)6, SO4, and PO4 adsorption by gibbsite , kaolinite , goethite, and birnessite...pKa triple layer surface complexation modeling of Sb(OH)6, SO4, and PO4 adsorption by gibbsite , kaolinite , goethite, and birnessite...Competition Surface Complexation Triple Layer Model Gibbsite Kaolinite Goethite Birnessite xviii Abstract Background. Antimony (Sb) is a

  6. Discovery of palladium, antimony, tellurium, iodine, and xenon isotopes

    SciTech Connect

    Kathawa, J.; Fry, C.; Thoennessen, M.

    2013-01-15

    Currently, thirty-eight palladium, thirty-eight antimony, thirty-nine tellurium, thirty-eight iodine, and forty xenon isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  7. Antimony and arsenic biogeochemistry in the East China Sea

    NASA Astrophysics Data System (ADS)

    Ren, Jing-Ling; Zhang, Xu-Zhou; Sun, You-Xu; Liu, Su-Mei; Huang, Daji; Zhang, Jing

    2016-02-01

    The biogeochemical cycles of the metalloid elements arsenic and antimony in the East China Sea (ECS), one of the most important marginal seas for western Pacific, were examined in May 2011. Dissolved inorganic arsenic (As(V) and As(III)) and antimony (Sb(V) and Sb(III)) species were determined by selective hydride generation-atomic fluorescence spectrometry (HG-AFS). Results show that total dissolved inorganic arsenic (TDIAs; [TDIAs]=[As(V)]+[As(III)]) were moderately depleted in the surface water and enriched in the deep water. Arsenite (As(III)) showed different vertical profiles with that of TDIAs, with significant surface enrichment in the middle shelf region where the concentrations of phosphate were extremely low. Speciation of dissolved arsenic was subtly controlled by the stoichiometric molar ratio of arsenate (As(V)) to phosphate. The average As(V)/P ratio for the ECS in spring 2011 was 10.8×10-3, which is higher than previous results and indicates the arsenate stress. The concentrations of total dissolved inorganic antimony (TDISb; [TDISb]=[Sb(V)]+[Sb(III)]) were high near the Changjiang Estuary and the coastal area of Hangzhou Bay and decreased moderately off the coast. TDISb displayed moderate conservative behavior in the ECS that confirms by the correlations with salinity and dissolved aluminum. Different with that of As(III), antimonite (Sb(III)) concentrations were extremely lower in the ECS, with relative higher concentration appeared at the bottom layer which indicates the contribution from sediment-water interface. A preliminary box model was established to estimate the water-mass balance and antimony budgets for the ECS. Compared with other areas in the world, the concentrations of dissolved inorganic arsenic and antimony in the ECS remain at natural levels.

  8. Influence of combined pollution of antimony and arsenic on culturable soil microbial populations and enzyme activities.

    PubMed

    Wang, Qiongshan; He, Mengchang; Wang, Ying

    2011-01-01

    The effects of both combined and single pollution of antimony (Sb) and arsenic (As) in different concentrations on culturable soil microbial populations and enzyme activities were studied under laboratory conditions. Joint effects of both Sb and As were different from that of Sb or As alone. The inhibition rate of culturable soil microbial populations under Sb and As pollution followed the order: bacterial > fungi > actinomycetes. There existed antagonistic inhibiting effect on urease and acid phophatase and synergistic inhibiting effect on protease under the combined pollution of Sb (III) and As (III). Only urease appeared to be the most sensitive indicator under Sb (V) and As (V) pollution, and there existed antagonistic inhibiting effect on acid phophatase and synergistic inhibiting effect on urease and protease under Sb (V) and As (V) combined pollution at most time. In this study, we also confirmed that the trivalent states of Sb and As were more toxic to all the microbes tested and more inhibitory on microbial enzyme activities then their pentavalent counterparts. The results also suggest that not only the application rate of the two metalloids but also the chemical form of metalloids should be considered while assessing the effect of metalloid on culturable microbial populations and enzyme activities. Urease and acid phosphatase can be used as potential biomarkers to evaluate the intensity of Sb (III) and As (III) stress.

  9. Stimulation of cell division in the rat by NaCl, KCl, MgCl2, and CaCl2, and inhibition of the sodium chloride effect on the glandular stomach by ascorbic acid and beta-carotene.

    PubMed

    Lugli, S M; Lutz, W K

    1999-01-01

    Three questions associated with the stimulation of cell division by chloride salts have been investigated: (i) whether cations other than sodium show a similar effect, (ii) whether vitamins can have a preventive activity, and (iii) whether subchronic treatment with sodium chloride in the diet is also effective. Male Fischer 344 rats were given solutions of the chloride salts of sodium, potassium, magnesium, and calcium by oral gavage. Water was used for control. After 4 h, a 24-h osmotic minipump containing 5-bromo-2'-deoxyuridine was implanted subcutaneously. The forestomach and glandular stomach, as well as liver and bladder were analyzed immunohistochemically 24 h later for the proportion of cells in S phase as an indicator of the rate of replicative DNA synthesis. For both the forestomach and the glandular stomach, potassium was as potent as sodium, and the divalent cations Mg and Ca were even more potent on a molar basis. Supplementation of the diet with ascorbic acid (2 g/kg food) or beta-carotene (12.5 mg/kg food) for 1 week before gavage of the sodium chloride solution resulted in an inhibition of the stimulation of cell division. A putative tumor-chemopreventive activity of the two vitamins might therefore not only rely on their antioxidative properties but may include effects on the cell cycle. A 4-week treatment with a sodium chloride supplement in the diet (2% and 4% supplement) resulted in a significant stimulation of cell division not only in both parts of the stomach and in the bladder (with the 4% supplement) but also in the liver (even with the 2% supplement). Sodium-chloride-stimulated cell turnover therefore is a sustained effect.

  10. Clinical and Parasitological Features of Patients with American Cutaneous Leishmaniasis that Did Not Respond to Treatment with Meglumine Antimoniate

    PubMed Central

    Robayo, Marta L.; Lopez, Myriam C.; Daza, Carlos D.; Bedoya, Angela; Mariño, Maria L.; Saavedra, Carlos H.

    2016-01-01

    Background American cutaneous leishmaniasis (ACL) is a complicated disease producing about 67.000 new cases per year. The severity of the disease depends on the parasite species; however in the vast majority of cases species confirmation is not feasible. WHO suggestion for ACL produced by Leishmania braziliensis, as first line treatment, are pentavalent antimonial derivatives (Glucantime or Sodium Stibogluconate) under systemic administration. According to different authors, pentavalent antimonial derivatives as treatment for ACL show a healing rate of about 75% and reasons for treatment failure are not well known. Methods In order to characterise the clinical and parasitological features of patients with ACL that did not respond to Glucantime, a cross-sectional observational study was carried out in a cohort of 43 patients recruited in three of the Colombian Army National reference centers for complicated ACL. Clinical and paraclinical examination, and epidemiological and geographic information were recorded for each patient. Parasitological, histopathological and PCR infection confirmation were performed. Glucantime IC50 and in vitro infectivity for the isolated parasites were estimated. Results Predominant infecting Leishmania species corresponds to L. braziliensis (95.4%) and 35% of the parasites isolated showed a significant decrease in in vitro Glucanatime susceptibility associated with previous administration of the medicament. Lesion size and in vitro infectivity of the parasite are negatively correlated with decline in Glucantime susceptibility (Spearman: r = (-)0,548 and r = (-)0,726; respectively). Conclusion A negative correlation between lesion size and parasite resistance is documented. L. braziliensis was found as the main parasite species associated to lesion of patients that underwent treatment failure or relapse. The indication of a second round of treatment in therapeutic failure of ACL, produced by L. braziliensis, with pentavalent antimonial

  11. Perchlorate transport and inhibition of the sodium iodide symporter measured with the yellow fluorescent protein variant YFP-H148Q/I152L

    SciTech Connect

    Cianchetta, Stefano; Bernardo, Julie di; Romeo, Giovanni; Rhoden, Kerry J.

    2010-03-15

    Perchlorate is an environmental contaminant that impairs thyroid function by interacting with the sodium iodide symporter (NIS), the transporter responsible for iodide uptake in the thyroid gland. Perchlorate is well known as a competitive inhibitor of iodide transport by NIS, and recent evidence demonstrates that NIS can also transport perchlorate. In this study, we evaluated the yellow fluorescent protein (YFP) variant YFP-H148Q/I152L, as a genetically encodable biosensor of intracellular perchlorate concentration monitored by real-time fluorescence microscopy. Fluorescence of recombinant YFP-H148Q/I152L was suppressed by perchlorate and iodide with similar affinities of 1.2 mM and 1.6 mM, respectively. Perchlorate suppressed YFP-H148Q/I152L fluorescence in FRTL-5 thyroid cells and NIS-expressing COS-7 cells, but had no effect on COS-7 cells lacking NIS. Fluorescence changes in FRTL-5 cells were Na{sup +}-dependent, consistent with the Na{sup +}-dependence of NIS activity. Perchlorate uptake in FRTL-5 cells resulted in 10-fold lower intracellular concentrations than iodide uptake, and was characterized by a higher affinity (K{sub m} 4.6 muM for perchlorate and 34.8 muM for iodide) and lower maximal velocity (V{sub max} 6.8 muM/s for perchlorate and 39.5 muM/s for iodide). Perchlorate also prevented iodide-induced changes in YFP-H148Q/I152L fluorescence in FRTL-5 cells, with half-maximal inhibition occurring at 1.1-1.6 muM. In conclusion, YFP-H148Q/I152L detects perchlorate accumulation by thyroid and other NIS-expressing cells, and reveals differences in the kinetics of perchlorate versus iodide transport by NIS.

  12. Sodium phenylacetate inhibits the Ras/MAPK signaling pathway to induce reduction of the c-Raf-1 protein in human and canine breast cancer cells.

    PubMed

    Watanabe, Manabu; Miyajima, Nozomi; Igarashi, Maki; Endo, Yoshifumi; Watanabe, Natsuko; Sugano, Sumio

    2009-11-01

    An aromatic fatty acid, phenylacetate (PA), has been shown to have cytostatic, antitumor and cell differentiation-inducing effects on various kinds of tumors. Previously, we have demonstrated cell growth inhibition, malignant phenotype reduction and cell differentiation effects of sodium phenylacetate (NaPA) treatment in a canine mammary tumor cell line. To clarify the molecular mechanism of these effects, we examined the expression of Ras/MAPK signaling pathway-related molecules in human and canine breast cancer cell lines, and found that the level of c-Raf-1 protein was reduced by 5, 10 and 20 mM of NaPA treatments, though Ras activation was maintained. Dephosphorylation of c-Raf-1 at Serine (Ser) 259, Ser 338, and Ser 621 were also seen in NaPA-treated cells. Downstream factors in the pathway, such as mitogen-activated protein kinase/ERK kinase (MEK)1/2 and ERK1/2, showed decreased activity, and accordingly, expressions of cyclinD1, c-myc, and inactivation of p90 ribosomal S6 kinase (RSK), which are MAPK targets, were reduced. We also observed the reduction of cell-cycle-promoted molecules, such as cdc1/cdk2, cdk4, PCNA cyclin A, and cyclin B, and the increased expression of p27kip1. Furthermore, expression of an epithelial marker, E-cadherin, was increased by NaPA treatment. These results suggest that one of the molecular targets of NaPA treatment was the reduction of c-Raf-1 protein, and that its reduction results in the decrease of malignant characteristics of tumor cells through blockage of the Ras/MAPK signaling pathway.

  13. Tumor growth inhibition, apoptosis, and Bcl-2 down-regulation of MCF-7ras tumors by sodium phenylacetate and tamoxifen combination.

    PubMed

    Adam, L; Crépin, M; Isräel, L

    1997-03-15

    We demonstrated previously the antitumoral and antiproliferative effects of sodium phenylacetate (NaPA) on malignant breast epithelial MCF-7ras cells and its lack of toxicity. The present in vivo protocols were as follows: (1) a control group; (2) a NaPA-receiving group (450 mg/kg) through s.c. osmotic pumps (ALZA Corp.) for 2 weeks, followed by 2 weeks with no treatment; and (3) a tamoxifen (TAM)-receiving group (20 mg/kg two times per week). The second group was further divided as follows: (a) a group receiving same doses of NaPA; (b) a TAM-receiving group; and (c) a group receiving both NaPA and TAM. Although tumors treated by TAM alone (group 3) showed progressive regrowth after 6 weeks, indicating an escape from antiestrogen inhibition, the TAM-administered group, following 2 weeks of NaPA pretreatment (group 2b), showed significant tumor regression of about 40% after 8 weeks. This effect was amplified to over 60% (P < 0.001) by simultaneous administration of the two drugs (group 2c). The last group displayed about 30% apoptotic-like nuclei, together with lower proliferation index, and less tumor vascularization, as compared to less than 5% terminal deoxytransferase-mediated dUTP-X nick end labeling-positive nuclei, highly vascularized tumors, in the TAM-treated group. Furthermore, in vitro administration of 4-OH-tamoxifen induced a Bcl-2 up-regulation in MCF-7ras cells, which was completely abolished by NaPA pretreatment. The combination of NaPA and OHT induced significant cell differentiation with cell cycle accumulation in the G0-G1 phase.

  14. Sodium phenylacetate induces growth inhibition and Bcl-2 down-regulation and apoptosis in MCF7ras cells in vitro and in nude mice.

    PubMed

    Adam, L; Crépin, M; Savin, C; Israël, L

    1995-11-15

    Using a highly tumorigenic human breast cancer model (Ha-ras-transfected MCF7 cell line) we analyzed the efficacy of the differentiation-inducing agent sodium phenylacetate (NaPA), both in vitro and in vivo. NaPA-treated MCF7ras cells showed dose-dependent growth inhibition from 2.5 to 15 mM without apparent toxicity. Western blot analysis showed a Bcl-2 down-regulation after 48 h treatment with 5 mM NaPA, together with apparition of apoptotic nuclei by DAPI staining. Mice bearing MCF7ras xenografts (n = 40) were treated for 2 weeks through s.c.-delivering osmotic pumps, followed by 6 weeks of daily i.p. NaPA administration. After 3 weeks, the treated tumors showed growth arrest without regression for the whole observation time, e.g., 12 weeks. Immunohistochemical analysis showed Bcl-2 down-regulation and differentiation patterns: decrease of Ki-67 and increase of steroid receptors (estrogen and progesterone receptors) compared to controls. Cells cultured from treated tumors (II.b) displayed pseudotrabecular disposition as MCF7ras cells treated in vitro. They also showed a higher NaPA sensitivity, together with 70% Bcl-2 down-regulation as compared to the derived cells of untreated tumors (II.a). When reinjected into nude mice, II.b cells induced only one poorly vascularized, noninvasive tumor (8%) with lower proliferation index, 100% progesterone receptor positive cells, and 35% terminal deoxynucleotidyltransferase-mediated dUTP-X nick end labeling (+) nuclei, as compared to 100% induction of highly vascularized and invasive tumors with 3% terminal deoxynucleotidyltransferase-mediated dUTP-X nick end labeling (+) nuclei induced by II.a cells.

  15. Inhibition of dextran sulfate sodium (DSS)-induced intestinal inflammation via enhanced IL-10 and TGF-beta production by galectin-9 homologues isolated from intestinal parasites.

    PubMed

    Kim, Joo-Young; Cho, Min Kyoung; Choi, Seon Hee; Lee, Keun Hee; Ahn, Soon Cheol; Kim, Dong-Hee; Yu, Hak Sun

    2010-11-01

    We isolated a galectin-9 (Gal-9) homologue gene (Tl-gal) from an adult worm of the canine gastrointestinal nematode parasite, Toxascaris leonina, via random cDNA library sequencing. The deduced amino acid sequence of the Tl-gal genes evidenced an identity of 89% with the galectin of Dirofilaria immitis, 87% identity with the galectin of Brugia malayi, and 35% identity with the human GAL-9 gene. To evaluate immune modulate function of Tl-GAL in host inflammatory response, we constructed recombinant Tl-GAL (rTl-GAL) using an Escherichia coli expression vector system and treated to intestinal inflammation mice. Although the carbohydrate-binding ability of rTl-GAL was less than that of rat galectin, we confirmed that recombinant rTl-GAL has carbohydrate-binding activity. The clinical symptoms of dextran sulfate sodium (DSS)-treated mice after rTl-GAL pre-treatment were found to be minimized, or less profound, as compared to those of the rTl-GAL untreated group. Additionally, the DSS-treated mice exhibited a significant shortening of the colon, but the large intestines of the rTl-GAL pre-treated mice were longer than those of the control group (P<0.05). Additionally, the rTl-GAL treated group exhibited significantly increased the levels of TGF-beta and IL-10 (P<0.05). The production of these regulatory cytokines may ameliorate intestinal inflammation. These findings demonstrate that rTl-GAL could inhibit inflammation reactions via the inhibition of Th1 and Th2 cytokine production by increasing the production of TGF-beta and IL-10 cytokines. The rTl-GAL may induce TGF-beta expression, primarily via the activation of the p38 pathway. In conclusion, rTl-GAL may function like a host galectin, thus functioning as a regulatory molecule in the host immune system; rTl-GAL may prove useful in the design of novel therapeutic intervention strategies for the treatment of allergic and immune diseases.

  16. Antimony and arsenic biogeochemistry in the western Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Cutter, Gregory A.; Cutter, Lynda S.; Featherstone, Alison M.; Lohrenz, Steven E.

    The subtropical to equatorial Atlantic Ocean provides a unique regime in which one can examine the biogeochemical cycles of antimony and arsenic. In particular, this region is strongly affected by inputs from the Amazon River and dust from North Africa at the surface, and horizontal transport at depth from high-latitude northern (e.g., North Atlantic Deep Water) and southern waters (e.g., Antarctic Bottom and Intermediate Waters). As a part of the 1996 Intergovernmental Oceanographic Commission's Contaminant Baseline Survey, data for dissolved As(III+V), As(III), mono- and dimethyl arsenic, Sb(III+V), Sb(III), and monomethyl antimony were obtained at six vertical profile stations and 44 sites along the 11,000 km transect from Montevideo, Uruguay, to Bridgetown, Barbados. The arsenic results were similar to those in other oceans, with moderate surface depletion, deep-water enrichment, a predominance of arsenate (>85% As(V)), and methylated arsenic species and As(III) in surface waters that are likely a result of phytoplankton conversions to mitigate arsenate "stress" (toxicity). Perhaps the most significant discovery in the arsenic results was the extremely low concentrations in the Amazon Plume (as low as 9.8 nmol/l) that appear to extend for considerable distances offshore in the equatorial region. The very low concentration of inorganic arsenic in the Amazon River (2.8 nmol/l; about half those in most rivers) is probably the result of intense iron oxyhydroxide scavenging. Dissolved antimony was also primarily in the pentavalent state (>95% antimonate), but Sb(III) and monomethyl antimony were only detected in surface waters and displayed no correlations with biotic tracers such as nutrients and chlorophyll a. Unlike As(III+V)'s nutrient-type vertical profiles, Sb(III+V) displayed surface maxima and decreased into the deep waters, exhibiting the behavior of a scavenged element with a strong atmospheric input. While surface water Sb had a slight correlation with

  17. BioGeochemistry of antimony, Sources, Transfers, Impacts and Assessment

    NASA Astrophysics Data System (ADS)

    Le Roux, Gael; Pinelli, Eric; Hedde, Mickael; Guiresse, Maritxu; De Vleeschouwer, François; Silvestre, Jérôme; Enrico, Maxime; Gandois, Laure; Monna, Fabrice; Gers, Charles; Probst, Anne

    2013-04-01

    BioGeoSTIB is a project funded by ADEME (French Environmental Protection Agency). Its aim is to provide a better understanding of biogeochemical cycle disturbances of antimony by man. Specifically, it is focused on the atmosphere-soil-organism interfaces. Based on a multi-scale approach, the impact of antimony on organisms and organism communities and the factors of Sb dispersion in the environment aim to better characterized. This report gives the main results of 2 and 1 -2 years of research. Using peat bogs as environmental archives, we show that Sb contamination in soils date back to the beginning of the metallurgy. Atmospheric deposition of Sb largely increased by 100 times during the Industrial Revolution compared to natural levels (~0,001-0,01 mg m-2 an-1) estimated in the deepest peat layers. This disturbance in the antimony geochemical cycle modified its concentrations in soils. One main source of present Sb contamination is automotive traffic due to Sb in braking lines. This emerging contamination was characterized close to a roundabout. This additional source of Sb does not seem to impact soil fauna but Sb concentrations in soil solutions exceed 1 μg L-1. Genotoxicity tests have been performed on the model plant Vicia faba and show that antimony is genotoxic at its lowest concentrations and that there is a synergistic effect lead, a trace metal frequently found in association with antimony in the environment. It is a main issue to determine Sb critical loads in the environment but main identified lacks are thermodynamic data, which are not available yet, to model the behavior of Sb in soil solutions and the fact the antimony is always associated with other anthropogenic trace metals like lead. Critical thresholds of Sb have been determined for the first time based on genotoxicity experiment. Simulations show that these thresholds can be exceeded in the future, whereas present limits for invertebrates (US-EPA) are and will not be reached. However

  18. Identification of antimony- and arsenic-oxidizing bacteria associated with antimony mine tailing.

    PubMed

    Hamamura, Natsuko; Fukushima, Koh; Itai, Takaaki

    2013-01-01

    Antimony (Sb) is a naturally occurring toxic element commonly associated with arsenic (As) in the environment and both elements have similar chemistry and toxicity. Increasing numbers of studies have focused on microbial As transformations, while microbial Sb interactions are still not well understood. To gain insight into microbial roles in the geochemical cycling of Sb and As, soils from Sb mine tailing were examined for the presence of Sb- and As-oxidizing bacteria. After aerobic enrichment culturing with As(III) (10 mM) or Sb(III) (100 μM), pure cultures of Pseudomonas- and Stenotrophomonas-related isolates with Sb(III) oxidation activities and a Sinorhizobium-related isolate capable of As(III) oxidation were obtained. The As(III)-oxidizing Sinorhizobium isolate possessed the aerobic arsenite oxidase gene (aioA), the expression of which was induced in the presence of As(III) or Sb(III). However, no Sb(III) oxidation activity was detected from the Sinorhizobium-related isolate, suggesting the involvement of different mechanisms for Sb and As oxidation. These results demonstrate that indigenous microorganisms associated with Sb mine soils are capable of Sb and As oxidation, and potentially contribute to the speciation and mobility of Sb and As in situ.

  19. The use of silver nanoparticles as an effective modifier for the determination of arsenic and antimony by electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Gunduz, S.; Akman, S.; Baysal, A.; Kahraman, M.

    2010-04-01

    Silver nanoparticles (AgNPs) were proposed as a new chemical modifier for the elimination of interferences when determining arsenic and antimony in aqueous NaCl or Na 2SO 4 solutions and in sea-water by electrothermal atomic absorption spectrometry. For this purpose, the AgNPs were prepared simply by reducing silver nitrate with sodium citrate. The effects of pyrolysis and atomization temperatures and the amounts of interferents and modifiers on the sensitivities of these elements were investigated. In the presence of the proposed modifier, a pyrolysis temperature of at least 1100 °C for arsenic and 900 °C for antimony could be applied without the loss of analytes, and the interferences were greatly reduced to allow for interference-free determination. The detection limits ( N = 10, 3 σ) for arsenic and antimony were 0.022 ng and 0.046 ng, respectively. AgNPs are cheaper and more available compared to many other modifiers. No background was detected, and the blank values were negligible.

  20. Antimony-assisted carbonization of Si(111) with solid source molecular beam epitaxy

    SciTech Connect

    Hackley, Justin; Richardson, Christopher J. K.; Sarney, Wendy L.

    2013-11-15

    The carbonization of an antimony-terminated Si (111) surface in a solid source molecular beam epitaxy system is presented. Reflection high-energy electron diffraction, atomic force microscopy, x-ray photoelectron spectroscopy, and cross-sectional transmission electron microscopy are used to characterize samples grown with and without antimony termination. It is shown that the antimony-terminated surface promotes the formation of thin, smooth and continuous SiC films at a relatively low temperature of 800 °C.

  1. Surface segregation of antimony in Fe-Si steel for grain oriented sheets

    NASA Astrophysics Data System (ADS)

    Jenko, M.; Vodopivec, F.; Praček, B.

    1993-06-01

    Surface segregation of antimony in a polycrystalline Fe-Si alloy with 0.049 wt% Sb was investigated by Auger electron spectroscopy in the temperature range from 450 to 800°C, and the segregation kinetics of antimony were described. From the surface segregation kinetics and its temperature dependence the bulk diffusion coefficient of antimony and the activation energy were determined in the temperature range from 500 to 600°C.

  2. Selective synthesis of ternary copper-antimony sulfide nanocrystals.

    PubMed

    Xu, Dongying; Shen, Shuling; Zhang, Yejun; Gu, Hongwei; Wang, Qiangbin

    2013-11-18

    Ternary copper-antimony sulfide nanocrystals (CAS NCs) have attracted increasing attention in photovoltaics and photoelectric nanodevices due to their tunable band gaps in the near-IR regime. Although much progress in the synthesis of CAS NCs has been achieved, the selective synthesis of CAS NCs with controllable morphologies and compositions is preliminary: in particular, a facile method is still in demand. In this work, we have successfully selectively synthesized high-quality CAS NCs with diverse morphologies, compositions, and band gaps, including rectangular CuSbS2 nanosheets (NSs), trigonal-pyramidal Cu12Sb4S13 NCs, and rhombic Cu3SbS3 NSs, by cothermodecomposition of copper diethyldithiocarbamate trihydrate (Cu(Ddtc)2) and antimony diethyldithiocarbamate trihydrate (Sb(Ddtc)3). The direct and indirect band gaps of the obtained CAS NCs were systematically studied by performing Kubelka-Munk transformations of their solid-state diffuse reflectance spectra.

  3. [Miltefosine versus meglumine antimoniate in the treatment of mucosal leishmaniasis].

    PubMed

    Garcia Bustos, Maria F; Barrio, Alejandra; Parodi, Cecilia; Beckar, Josefina; Moreno, Sonia; Basombrio, Miguel A

    2014-01-01

    The conventional treatment for tegumentary leishmaniasis is meglumine antimoniate, which needs parenteral administration, has increased therapeutic failure, and produces serious adverse effects, justifying the search for therapeutic alternatives. We report here the preliminary results of a phase II clinical trial in patients with mucosal leishmaniasis, in which the efficacy of oral miltefosine versus the antimonial compound was assessed. The evaluation of response to the treatment was performed by monitoring with nasopharyngeal video-fibroscopy, using a score of mucosal injury severity for patients at each follow-up point. We found no significant differences so far between the number of patients cured with miltefosine or conventional chemotherapy. The favorable results of this study suggest that miltefosine could be an effective and safe oral therapeutic alternative in the region.

  4. [Premature birth after the use of pentavalent antimonial: case report].

    PubMed

    Silveira, Bruna Pinheiro; Araújo Sobrinho, José; Leite, Lacínia Freire; Sales, Maria das Neves Andrade; Gouveia, Maria do Socorro Araújo; Mathias, Renato Leal; Guedes Filho, Ricardo Amorim; Barbosa, Sônia Maria

    2003-01-01

    A case is reported of a 19-year-old woman, at week 24 of gestation, with visceral leishmaniosis. She was treated with meglumine antimoniate at a dose of 850 mg/day for 20 days. There occurred premature birth on day five of treatment and the neonate died one day after birth. Considering the importance of protozoiasis in our population and the rarity of the association with pregnancy, we resolved to publish the case.

  5. Comparison of Meglumine Antimoniate and Pentamidine for Peruvian Cutaneous Leishmaniasis

    DTIC Science & Technology

    2005-01-01

    2002. Patients. The patients lived in and around the city of Cusco, Peru and presented with a clinical diagnosis of cutaneous leishmaniasis ...for investigation of chemotherapeutic agents in leishmaniasis . J Infect Dis 142: 83–86. 8. Davey RT, Masur H, 1990. Recent advances in the diagnosis ...COMPARISON OF MEGLUMINE ANTIMONIATE AND PENTAMIDINE FOR PERUVIAN CUTANEOUS LEISHMANIASIS ELLEN M. ANDERSEN, MARIA CRUZ-SALDARRIAGA, ALEJANDRO LLANOS

  6. Correlation of CsK2Sb photocathode lifetime with antimony thickness

    SciTech Connect

    Mamun, M. A.; Hernandez-Garcia, C.; Poelker, M.; Elmustafa, A. A.

    2015-06-01

    CsK2Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  7. Correlation of CsK{sub 2}Sb photocathode lifetime with antimony thickness

    SciTech Connect

    Mamun, M. A. Elmustafa, A. A.; Hernandez-Garcia, C.; Poelker, M.

    2015-06-01

    CsK{sub 2}Sb photocathodes with quantum efficiency on the order of 10% at 532 nm, and lifetime greater than 90 days at low voltage, were successfully manufactured via co-deposition of alkali species emanating from an effusion source. Photocathodes were characterized as a function of antimony layer thickness and alkali consumption, inside a vacuum chamber that was initially baked, but frequently vented without re-baking. Photocathode lifetime measured at low voltage is correlated with the antimony layer thickness. Photocathodes manufactured with comparatively thick antimony layers exhibited the best lifetime. We speculate that the antimony layer serves as a reservoir, or sponge, for the alkali.

  8. Sodium Test

    MedlinePlus

    ... AACC products and services. Advertising & Sponsorship: Policy | Opportunities Sodium Share this page: Was this page helpful? Also known as: Na Formal name: Sodium Related tests: Chloride , Bicarbonate , Potassium , Electrolytes , Osmolality , Basic ...

  9. Sodium Oxybate

    MedlinePlus

    Sodium oxybate is used to prevent attacks of cataplexy (episodes of muscle weakness that begin suddenly and ... urge to sleep during daily activities, and cataplexy). Sodium oxybate is in a class of medications called ...

  10. Sodium - blood

    MedlinePlus

    ... naproxen Lower than normal sodium level is called hyponatremia. It may be due to: Use of medicines ... overview Hepatorenal syndrome Hyperaldosteronism - primary and secondary Hypopituitarism Hypothyroidism Ions Low sodium level Nephrotic syndrome Sweating Review ...

  11. Kinetics and mechanism of photopromoted oxidative dissolution of antimony trioxide.

    PubMed

    Hu, Xingyun; Kong, Linghao; He, Mengchang

    2014-12-16

    Light (sunlight, ultraviolet, simulated sunlight) irradiation was used to initiate the dissolution of antimony trioxide (Sb2O3). Dissolution rate of Sb2O3 was accelerated and dissolved trivalent antimony (Sb(III)) was oxidized in the irradiation of light. The photopromoted oxidative dissolution mechanism of Sb2O3 was studied through experiments investigating the effects of pH, free radicals scavengers, dissolved oxygen removal and Sb2O3 dosage on the release rate of antimony from Sb2O3 under simulated sunlight irradiation. The key oxidative components were hydroxyl free radicals, photogenerated holes and superoxide free radicals; their contribution ratios were roughly estimated. In addition, a conceptual model of the photocatalytic oxidation dissolution of Sb2O3 was proposed. The overall pH-dependent dissolution rate of Sb2O3 and the oxidation of Sb(III) under light irradiation were expressed by r = 0.08 ·[OH(-)](0.63) and rox = 0.10 ·[OH(-)](0.79). The present study on the mechanism of the photo-oxidation dissolution of Sb2O3 could help clarify the geochemical cycle and fate of Sb in the environment.

  12. Sodium Bicarbonate

    MedlinePlus

    ... to 2 hours after meals, with a full glass of water. If you are using sodium bicarbonate for another reason, it may be taken with or without food. Do not take sodium bicarbonate on an overly full stomach.Dissolve sodium bicarbonate powder in at least 4 ounces (120 milliliters) of ...

  13. The curing agent sodium nitrite, used in the production of fermented sausages, is less inhibiting to the bacteriocin-producing meat starter culture Lactobacillus curvatus LTH 1174 under anaerobic conditions.

    PubMed

    Verluyten, Jurgen; Messens, Winy; De Vuyst, Luc

    2003-07-01

    Curvacin A is a listericidal bacteriocin produced by Lactobacillus curvatus LTH 1174, a strain isolated from fermented sausage. The response of this strain to an added curing agent (sodium nitrite) in terms of cell growth and bacteriocin production was investigated in vitro by laboratory fermentations with modified MRS broth. The strain was highly sensitive to nitrite; even a concentration of 10 ppm of curing agent inhibited its growth and both volumetric and specific bacteriocin production. A meat simulation medium containing 5 ppm of sodium nitrite was tested to investigate the influence of the gas phase on the growth and bacteriocin production of L. curvatus LTH 1174. Aerating the culture during growth had no effect on biomass formation, but the oxidative stress caused a higher level of specific bacteriocin production and led to a metabolic shift toward acetic acid production. Anaerobic conditions, on the other hand, led to an increased biomass concentration and less growth inhibition. Also, higher maximum volumetric bacteriocin activities and a higher level of specific bacteriocin production were obtained in the presence of sodium nitrite than in fermentations under aerobic conditions or standard conditions of air supply. These results indicate that the inhibitory effect of the curing agent is at least partially masked under anaerobic conditions.

  14. Antimony leaching from polyethylene terephthalate (PET) plastic used for bottled drinking water.

    PubMed

    Westerhoff, Paul; Prapaipong, Panjai; Shock, Everett; Hillaireau, Alice

    2008-02-01

    Antimony is a regulated contaminant that poses both acute and chronic health effects in drinking water. Previous reports suggest that polyethylene terephthalate (PET) plastics used for water bottles in Europe and Canada leach antimony, but no studies on bottled water in the United States have previously been conducted. Nine commercially available bottled waters in the southwestern US (Arizona) were purchased and tested for antimony concentrations as well as for potential antimony release by the plastics that compose the bottles. The southwestern US was chosen for the study because of its high consumption of bottled water and elevated temperatures, which could increase antimony leaching from PET plastics. Antimony concentrations in the bottled waters ranged from 0.095 to 0.521 ppb, well below the US Environmental Protection Agency (USEPA) maximum contaminant level (MCL) of 6 ppb. The average concentration was 0.195+/-0.116 ppb at the beginning of the study and 0.226+/-0.160 ppb 3 months later, with no statistical differences; samples were stored at 22 degrees C. However, storage at higher temperatures had a significant effect on the time-dependent release of antimony. The rate of antimony (Sb) release could be fit by a power function model (Sb(t)=Sb 0 x[Time, h]k; k=8.7 x 10(-6)x[Temperature ( degrees C)](2.55); Sb 0 is the initial antimony concentration). For exposure temperatures of 60, 65, 70, 75, 80, and 85 degrees C, the exposure durations necessary to exceed the 6 ppb MCL are 176, 38, 12, 4.7, 2.3, and 1.3 days, respectively. Summertime temperatures inside of cars, garages, and enclosed storage areas can exceed 65 degrees C in Arizona, and thus could promote antimony leaching from PET bottled waters. Microwave digestion revealed that the PET plastic used by one brand contained 213+/-35 mgSb/kg plastic; leaching of all the antimony from this plastic into 0.5L of water in a bottle could result in an antimony concentration of 376 ppb. Clearly, only a small

  15. Heavy weight vehicle traffic and its relationship with antimony content in human blood.

    PubMed

    Quiroz, Waldo; De Gregori, Ida; Basilio, Paola; Bravo, Manuel; Pinto, Marcela; Lobos, Maria Gabriela

    2009-05-01

    Brake pads systems are nowadays considered as one of the most important sources of antimony in airborne particulate matter. One way that antimony can enter the body is through the lungs and specially by the interaction of antimony with -SH groups present in erythrocyte membrane cells. In spite of that, there are no studies about antimony enrichment in blood of workers exposed to high vehicle traffic. Port workers are generally exposed to heavy weight vehicle traffic. In Chile the biggest marine port is found in Valparaíso City. In this study antimony in whole blood and its fractions (erythrocytes-plasma and erythrocytes membranes-cytoplasm) of 45 volunteers were determined. The volunteers were port workers from Valparaíso city, and two control groups, one from Valparaíso and another from Quebrada Alvarado, the latter being a rural area located about 100 Km away from Valparaíso. The results demonstrate that port workers are highly impacted by antimony emissions from heavy weight vehicle traffic showing an average concentration of 27 +/- 9 ng Sb kg(-1), 5-10 times higher than the concentration of antimony in the blood of control groups. These are the highest antimony levels in blood ever reported in the literature. The highest antimony percentages (>60%) were always found in the erythrocyte fractions. However, the exposure degree to vehicle traffic is significant over antimony distribution in plasma, erythrocytes and cytoplasm. This results shows that the antimony mass in the erythrocyte membranes, was approximately constant at 1.0 +/- 0.1 ng Sb g(-1) of whole blood in all blood samples analyzed.

  16. Effects of sodium cromoglycate and nedocromil sodium on histamine secretion from human lung mast cells.

    PubMed Central

    Leung, K B; Flint, K C; Brostoff, J; Hudspith, B N; Johnson, N M; Lau, H Y; Liu, W L; Pearce, F L

    1988-01-01

    Sodium cromoglycate and nedocromil sodium produced a dose dependent inhibition of histamine secretion from human pulmonary mast cells obtained by bronchoalveolar lavage and by enzymatic dissociation of lung parenchyma. Both compounds were significantly more active against the lavage cells than against the dispersed lung cells, and nedocromil sodium was an order of magnitude more effective than sodium cromoglycate against both cell types. Tachyphylaxis was observed with the parenchymal cells but not with the lavage cells. Nedocromil sodium and sodium cromoglycate also inhibited histamine release from the lavage cells of patients with sarcoidosis and extrinsic asthma. PMID:2462755

  17. Sirtuin-2 inhibition affects hippocampal functions and sodium butyrate ameliorates the reduction in novel object memory, cell proliferation, and neuroblast differentiation

    PubMed Central

    Jung, Hyo Young; Yoo, Dae Young; Kim, Jong Whi; Kim, Dae Won; Choi, Jung Hoon; Chung, Jin Young; Won, Moo-Ho; Yoon, Yeo Sung

    2016-01-01

    We investigated the effects of the sirtuin-2 (SIRT2) inhibitor AK-7 on novel object memory, cell proliferation, and neuroblast differentiation in the dentate gyrus. In addition, we also observed the relationships with sodium butyrate, a histone deacetylase inhibitor, on the hippocampal functions. To investigate the effects of AK-7 on hippocampal functions, 10-week-old C57BL/6 mice were daily injected intraperitoneally with 20 mg/kg AK-7 alone or in combination with subcutaneous administration of 300 mg/kg sodium butyrate, a histone deacetylase inhibitor, for 21 days. A novel object recognition test was conducted on days 20 (training) and 21 (testing) of treatment. Thereafter, the animals were sacrificed for immunohistochemistry for Ki67 (cell proliferation) and doublecortin (DCX, neuroblast differentiation). AK-7 administration significantly reduced the time spent exploring new objects, while treatment in combination with sodium butyrate significantly alleviated this reduction. Additionally, AK-7 administration significantly reduced the number of Ki67-positive cells and DCX-immunoreactive neuroblasts in the dentate gyrus, while the treatment in combination with sodium butyrate ameliorated these changes. This result suggests that the reduction of SIRT2 may be closely related to age-related phenotypes including novel object memory, as well as cell proliferation and neuroblast differentiation in the dentate gyrus. In addition, sodium butyrate reverses SIRT2-related age phenotypes. PMID:28053616

  18. Sodium ascorbate inhibits growth via the induction of cell cycle arrest and apoptosis in human malignant melanoma A375.S2 cells.

    PubMed

    Lin, Shuw-Yuan; Lai, Wan-Wen; Chou, Chi-Chung; Kuo, Hsiu-Maan; Li, Te-Mao; Chung, Jing-Gung; Yang, Jen-Hung

    2006-12-01

    Vitamin C has been reported to be useful in the treatment and prevention of cancer. Inconsistent effects from growth stimulation to induction of apoptosis of malignant tumor cells, however, have been reported. Melanoma is an increasingly common and potentially lethal malignancy. It was reported that melanoma cells were more susceptible to ascorbate toxicity than any other tumor cells. The mechanisms accounting for ascorbate-induced apoptosis in human melanoma cells, however, have remained unclear. This study was undertaken to investigate the effect of sodium ascorbate on cytotoxicity and apoptosis in human malignant melanoma A375.S2 cells. A375.S2 cells were incubated with a certain range of concentrations of sodium ascorbate for various time periods. In order to examine the effects of sodium ascorbate on cell proliferation, cell cycle, apoptosis and necrosis, we performed 4,6-diamidino-2-phenylindole dihydrochloride assays and flow cytometry analysis. Polymerase chain reaction was used to examine the mRNA levels of p53, p21, p27, cyclin A, cyclin E, CDK2 and CDK4, which are associated with cell cycle S-phase arrest and apoptosis. Flow cytometric analysis showed that sodium ascorbate significantly induced cell cycle arrest and apoptosis in the A375.S2 cell line in a dose-dependent manner. The increased expressions of p53 and p21, and the decreased expressions of cyclin A, cyclin E, CDK2 and CDK4, indicated the cell cycle arrest at G1/S phase after the cells had been treated with sodium ascorbate. Induction of apoptosis involved an increase in the levels of p53, p21 and cellular Ca, and a decrease in mitochondrial membrane potential and activation of caspase 3 before culminating in apoptosis in sodium ascorbate-treated A375.S2 cells.

  19. The Hydrothermal Chemistry of Gold, Arsenic, Antimony, Mercury and Silver

    SciTech Connect

    Bessinger, Brad; Apps, John A.

    2003-03-23

    A comprehensive thermodynamic database based on the Helgeson-Kirkham-Flowers (HKF) equation of state was developed for metal complexes in hydrothermal systems. Because this equation of state has been shown to accurately predict standard partial molal thermodynamic properties of aqueous species at elevated temperatures and pressures, this study provides the necessary foundation for future exploration into transport and depositional processes in polymetallic ore deposits. The HKF equation of state parameters for gold, arsenic, antimony, mercury, and silver sulfide and hydroxide complexes were derived from experimental equilibrium constants using nonlinear regression calculations. In order to ensure that the resulting parameters were internally consistent, those experiments utilizing incompatible thermodynamic data were re-speciated prior to regression. Because new experimental studies were used to revise the HKF parameters for H2S0 and HS-1, those metal complexes for which HKF parameters had been previously derived were also updated. It was found that predicted thermodynamic properties of metal complexes are consistent with linear correlations between standard partial molal thermodynamic properties. This result allowed assessment of several complexes for which experimental data necessary to perform regression calculations was limited. Oxygen fugacity-temperature diagrams were calculated to illustrate how thermodynamic data improves our understanding of depositional processes. Predicted thermodynamic properties were used to investigate metal transport in Carlin-type gold deposits. Assuming a linear relationship between temperature and pressure, metals are predicted to predominantly be transported as sulfide complexes at a total aqueous sulfur concentration of 0.05 m. Also, the presence of arsenic and antimony mineral phases in the deposits are shown to restrict mineralization within a limited range of chemical conditions. Finally, at a lesser aqueous sulfur

  20. Electrostatically defined silicon quantum dots with counted antimony donor implants

    SciTech Connect

    Singh, M. Luhman, D. R.; Lilly, M. P.; Pacheco, J. L.; Perry, D.; Garratt, E.; Ten Eyck, G.; Bishop, N. C.; Wendt, J. R.; Manginell, R. P.; Dominguez, J.; Pluym, T.; Bielejec, E.; Carroll, M. S.

    2016-02-08

    Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. In this work, a focused ion beam is used to implant antimony donors in 100 nm × 150 nm windows straddling quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of donors implanted can be counted to a precision of a single ion. In low-temperature transport measurements, regular Coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization are also observed in devices with counted donor implants.

  1. Sodium in diet

    MedlinePlus

    Diet - sodium (salt); Hyponatremia - sodium in diet; Hypernatremia - sodium in diet; Heart failure - sodium in diet ... The body uses sodium to control blood pressure and blood volume. Your body also needs sodium for your muscles and nerves to work ...

  2. Meta-Analysis of the Effect of Dietary Sodium Restriction with or without Concomitant Renin-Angiotensin-Aldosterone System–Inhibiting Treatment on Albuminuria

    PubMed Central

    D’Elia, Lanfranco; Rossi, Giovanni; Schiano di Cola, Michele; Savino, Ivana; Galletti, Ferruccio

    2015-01-01

    Background and objectives Urinary albumin excretion and/or albumin to creatinine ratio are associated with CKD and higher risk of cardiovascular events. Several studies investigated the effect of reduced dietary sodium intake on urinary albumin excretion and/or albumin to creatinine ratio in adult patient populations, but the majority was inconclusive because of insufficient statistical power. A meta-analysis of the randomized, controlled trials available could overcome this problem and lead to more definitive conclusions. Design, setting, participants, & measurements A systematic search of the online databases available (from 1996 to October of 2014) was conducted of randomized, controlled trials that expressed urinary albumin excretion or albumin to creatinine ratio as the difference between the effects of two different sodium intake regimens. For each study, the mean difference and 95% confidence intervals were pooled using a random effect model. Heterogeneity, publication bias, subgroup, and meta-regression analyses were performed. Results Eleven studies met the predefined inclusion criteria and provided 23 cohorts with 516 participants and 1–6 weeks of follow-up time. In the pooled analysis, an average reduction in sodium intake of 92 mmol/d was associated with a 32.1% (95% confidence interval, −44.3 to −18.8) reduction in urinary albumin excretion. The effect of sodium restriction was higher in the cohorts including patients on concomitant renin-angiotensin-aldosterone system–blocking therapy, in the studies with intervention lasting at least 2 weeks, and among participants with evidence of kidney damage. A greater reduction of urinary albumin excretion was associated with a higher decrease in BP during the intervention. The analysis of changes in albumin to creatinine ratio provided similar results. Conclusions This meta-analysis indicates that sodium intake reduction markedly reduces albumin excretion, more so during concomitant renin

  3. Molecular modeling, docking and ADMET studies towards development of novel Disopyramide analogs for potential inhibition of human voltage gated sodium channel proteins

    PubMed Central

    Meraj, Khunza; Mahto, Manoj Kumar; Christina, N Blessy; Desai, Nidhi; Shahbazi, Sajad; Bhaskar, Matcha

    2012-01-01

    The sodium “channelopathies” are the first among the ion channel diseases identified and have attracted widespread clinical and scientific interests. Human voltage gated sodium channels are sites of action of several antiarrhythmic drugs, local anesthetics and related antiepileptic drugs. The present study aims to optimize the activity of Disopyramide, by modification in its structures which may improve the drug action by reducing its side effects. Herein, we have selected Human voltage-gated sodium channel protein type 5 as a potent molecular target. Nearly eighty analogs of Disopyramide are designed and optimized. Thirty are selected for energy minimization using Discovery studio and the LigPrep 2.5. Prior to docking, the active sites of all the proteins are identified. The processing, optimization and minimization of all the proteins is done in Protein preparation wizard. The docking study is performed using the GLIDE. Finally top five ranked lead molecules with better dock scores are identified as having strong binding affinity to 2KAV protein than Disopyramide based on XP G scores. These five leads are further docked with other similar voltage gated sodium channel proteins (PDB IDs: 2KBI, 4DCK, 2L53 and 4DJC) and the best scoring analog with each protein is identified. Drug likeliness and comparative bioactivity analysis for all the analogs is done using QikProp 3.4. Results have shown that the top five lead molecules would have the potential to act as better drugs as compared to Disopyramide and would be of interest as promising starting point for designing compounds against various Sodium channelopathies. PMID:23275710

  4. Simultaneous lead and antimony immobilization in shooting range soil by a combined application of hydroxyapatite and ferrihydrite.

    PubMed

    Ogawa, Shouhei; Katoh, Masahiko; Sato, Takeshi

    2015-01-01

    This study investigated whether a combined application of hydroxyapatite and ferrihydrite could immobilize lead and antimony in shooting range soil in which the level of lead contamination is markedly higher than that of antimony. In addition, we evaluated the stability of lead and antimony immobilized by the combined application with varying soil pH. The levels of water-soluble lead and antimony for the combined application were lower than those of single applications of hydroxyapatite or ferrihydrite, indicating that the combined application could suppress the levels of water-soluble lead and antimony by 99.9% and 95.5%, respectively, as compared with the levels in shooting range soil without immobilization material. The amounts of residual lead and amorphous Fe/Al oxide-bound antimony fractions in sequential extraction increased with a decrease in the exchangeable and carbonate lead fractions as well as in non-specifically bound and specifically bound antimony fractions. The alteration of lead and antimony phases to chemically more stable ones as a result of the combined application would result in the suppression of their mobility. The stability of immobilized lead and antimony in the combined application was equal to that of lead with a single application of hydroxyapatite and that of antimony with a single application of ferrihydrite within neutral to alkaline pH conditions, respectively. Therefore, this study suggests that the combined application of hydroxyapatite and ferrihydrite can simultaneously immobilize lead and antimony in shooting range soil with neutral to alkaline pH.

  5. Antimony sulphide, an absorber layer for solar cell application

    NASA Astrophysics Data System (ADS)

    Ali, N.; Hussain, Arshad; Ahmed, R.; Shamsuri, W. N. Wan; Shaari, A.; Ahmad, N.; Abbas, S. M.

    2016-01-01

    Replacement of the toxic, expensive and scarce materials with nontoxic, cheap and earth-abundant one, in solar cell absorber layer, is immensely needed to realize the vision of green and sustainable energy. Two-micrometre-thin antimony sulphide film is considered to be adequate as an absorbing layer in solar cell applications. In this paper, we synthesize antimony sulphide thin films on glass substrate by physical vapour deposition technique, and the obtained films were then annealed at different temperatures (150-250 °C). The as-deposited and annealed samples were investigated for structural and optoelectronic properties using different characterization techniques. The X-ray diffraction analysis showed that the annealed samples were polycrystalline with Sb2S3 phase, while the as-deposited sample was amorphous in nature. The optical properties are measured via optical ellipsometric techniques. The measured absorbance of the film is adequately high, and every photon is found to be absorbed in visible and NIR range. The conductivity type of the films measured by hot-point probe technique is determined to be p-type. The optical band gap of the resulted samples was in the range (2.4-1.3 eV) for the as-deposited and annealed films.

  6. Transparent conducting aerogels of antimony-doped tin oxide.

    PubMed

    Correa Baena, Juan Pablo; Agrios, Alexander G

    2014-11-12

    Bulk antimony-doped tin oxide aerogels are prepared by epoxide-initiated sol-gel processing. Tin and antimony precursors are dissolved in ethanol and water, respectively, and propylene oxide is added to cause rapid gelation of the sol, which is then dried supercritically. The Sb:Sn precursor mole ratio is varied from 0 to 30% to optimize the material conductivity and absorbance. The materials are characterized by electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), nitrogen physisorption analysis, a four-point probe resistivity measurement, and UV-vis diffuse reflectance spectroscopy. The samples possess morphology typical of aerogels without significant change with the amount of doping. Calcination at 450 °C produces a cassiterite crystal structure in all aerogel samples. Introduction of Sb at 15% in the precursor (7.6% Sb by XPS) yields a resistivity more than 3 orders of magnitude lower than an undoped SnO2 aerogel. Calcination at 800 °C reduces the resistivity by an additional 2 orders of magnitude to 30 Ω·cm, but results in a significant decrease in surface area and pore volume.

  7. Antimony contamination and its effect on Trifolium plants

    NASA Astrophysics Data System (ADS)

    Corrales, Isabel; Barceló, Juan; Bech, Jaume; Poschenrieder, Charlotte

    2014-05-01

    Antimony is not an essential element and soil Sb contents usually are low.However, soil contamination by Sb has increased in the last years due to the human activities (combustion of fossil fuels, mining, waste incineration, smelting, shooting and road traffic). The main objective of this work was to study the effect of different concentrations of antimony (KSb(OH)6) in order to evaluate the effect on growth and Sb uptake on Trifolium pratense cv. Milvus and Trifolium repens. Our results show that Sb accumulated both in roots and shoots of clover without any negative effect on root growth, cellular viability and lipid peroxidation. This absence of toxicity sympthoms in clover plants could be very dangerous because Sb can be inadvertedly incorporated into the trophic chain causing toxic effects both in animals and humans. The absence of toxic effects on plants does not seem to be due to detoxification by phytochelatins because the use of the gamma-glutamylcysteine synthetase inhibitor, L-buthionine-[S,R]-sulphoximine (BSO) did not enhance Sb toxicity to plants. (Supported by the Spanish MICINN project BFU2010-14873)

  8. Thermoelectric Micro-Refrigerator Based on Bismuth/Antimony Telluride

    NASA Astrophysics Data System (ADS)

    Dang, Linh Tuan; Dang, Tung Huu; Nguyen, Thao Thi Thu; Nguyen, Thuat Tran; Nguyen, Hue Minh; Nguyen, Tuyen Viet; Nguyen, Hung Quoc

    2017-03-01

    Thermoelectric micro-coolers based on bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) are important in many practical applications thanks to their compactness and fluid-free circulation. In this paper, we studied thermoelectric properties of bismuth/antimony telluride (Bi/SbTe) thin films prepared by the thermal co-evaporation method, which yielded among the best thermoelectric quality. Different co-evaporation conditions such as deposition flux ratio of materials and substrate temperature during deposition were investigated to optimize the thermoelectric figure␣of merit of these materials. Micron-size refrigerators were designed and fabricated using standard lithography and etching technique. A three-layer structure was introduced, including a p-type layer, an n-type layer and an aluminum layer. Next to the main cooler, a pair of smaller Bi/SbTe junctions was used as a thermocouple to directly measure electron temperature of the main device. Etching properties of the thermoelectric materials were investigated and optimized to support the fabrication process of the micro-refrigerator. We discuss our results and address possible applications.

  9. Antimony in the environment: A review focused on natural waters. III. Microbiota relevant interactions

    NASA Astrophysics Data System (ADS)

    Filella, Montserrat; Belzile, Nelson; Lett, Marie-Claire

    2007-02-01

    Antimony is ubiquitously present in the environment as a result of natural processes and human activities. Antimony is not considered to be an essential element for plants or animals. In this third review paper on the occurrence of antimony in natural waters, the interactions of antimony with microbiota are discussed in relation to its fate in natural waters. This paper covers the following aspects: occurrence in microbiota, uptake transport mechanisms, pathways of Sb(III) removal from cells involved in antimony tolerance, oxidation and reduction of antimony by living organisms, phytochelatin induction and biomethylation. This review is based on a careful and systematic examination of a comprehensive collection of papers on the above mentioned aspects of the subject. All data are quoted from the original sources. Relatively little existing information falls within the strict scope of this review and, when relevant, discussion on the interactions of antimony with reference microorganisms, such as Escherichia coli, Saccharomyces cerevisiae and different protozoan parasites of the genus Leishmania, has been included.

  10. Glycoprotein isolated from Styrax japonica Siebold et al. Zuccarini inhibits oxidative and pro-inflammatory responses in HCT116 colonic epithelial cells and dextran sulfate sodium-treated ICR mice.

    PubMed

    Lee, Sei-Jung; Lee, Jin; Song, Sooyeon; Lim, Kye-Taek

    2016-01-01

    This study was carried out to investigate the anti-inflammatory potentials of a 38 kDa glycoprotein isolated from Styrax japonica Siebold et al Zuccarini (SJSZ glycoprotein). We found that SJSZ glycoprotein has concentration-dependent scavenging activity against DPPH and hydroxyl radicals in the cell-free systems. In colonic epithelial cells (HCT116 cells), the results showed that SJSZ glycoprotein inhibits the production of reactive oxygen species (ROS) induced by glucose/glucose oxidase (G/GO) in a concentration-dependent manner. Experimental mouse colitis was induced by adding dextran sulfate sodium (DSS) to the drinking water at a concentration of 4% (w/v) for 7 days. We figured out that administration of SJSZ glycoprotein (10 mg/kg) lowers the levels of disease activity index, myeloperoxidase activity, and histological inflammation in DSS-treated mice. In addition, SJSZ glycoprotein inhibited plasmic thiobarbituric acid reactive substances (TBARS) formation, nitric oxide (NO) production, and lactate dehydrogenase (LDH) release, accompanying the inhibition of colonic inflammatory signal proteins (NF-κB, iNOS, and COX-2) and inflammation-related cytokines (IL-1β, IL-6, and TNF-α). These results indicate that SJSZ glycoprotein inhibits oxidative and pro-inflammatory responses in mouse colitis.

  11. Sodium MRI.

    PubMed

    Ouwerkerk, Ronald

    2011-01-01

    Sodium ((23)Na) imaging has a place somewhere between (1)H-MRI and MR spectroscopy (MRS). Like MRS it potentially provides information on metabolic processes, but only one single resonance of ionic (23)Na is observed. Therefore pulse sequences do not need to code for a chemical shift dimension, allowing (23)Na images to be obtained at high resolutions as compared to MRS. In this chapter the biological significance of sodium in the brain will be discussed, as well as methods for observing it with (23)Na-MRI. Many vital cellular processes and interactions in excitable tissues depend on the maintenance of a low intracellular and high extracellular sodium concentration. Healthy cells maintain this concentration gradient at the cost of energy. Leaky cell membranes or an impaired energy metabolism immediately leads to an increase in cytosolic total tissue sodium. This makes sodium a biomarker for ischemia, cancer, excessive tissue activation, or tissue damage as might be caused by ablation therapy. Special techniques allow quantification of tissue sodium for the monitoring of disease or therapy in longitudinal studies or preferential observation of the intracellular component of the tissue sodium. New methods and high-field magnet technology provide new opportunities for (23)Na-MRI in clinical and biomedical research.

  12. Dalteparin sodium.

    PubMed

    Pineo, G F; Hull, R D

    2001-08-01

    Dalteparin sodium (Fragmin, Pharmacia Corporation) is a low molecular weight heparin (LMWH) with a mean molecular weight of approximately 5000 Da. As with the other LMWHs, dalteparin sodium has certain advantages over unfractionated heparin (UFH), most important of which are improved bio-availability by sc. injection, a prolonged antithrombotic activity which is highly correlated with body weight permitting the o.d. administration of the drug. Dalteparin sodium has been subjected to a large number of well-designed randomised clinical trials for the prevention and treatment of thrombotic disorders. Based on data from the randomised clinical trials, dalteparin sodium has been approved internationally for a wide spectrum of clinical indications (e.g., prevention of thromboembolic events after surgery). Dalteparin sodium has also been studied in randomised controlled trials in the maintenance of graft patentcy following peripheral vascular surgery, in place of warfarin for the long-term treatment of patients presenting with deep vein thrombosis (DVT), in the prevention of upper extremity thrombosis in patients with indwelling portacath devices and in pregnant patients with a history of previous venous thromboembolism with or without thrombophilia. Dalteparin sodium has been compared with heparin for the prevention of thrombotic complications during haemodyalisis and haemofiltration. These studies have shown promising results but further work is required before dalteparin sodium can be recommended for these indications.

  13. Probing the mechanism of sodium ion insertion into copper antimony Cu2Sb anodes

    DOE PAGES

    Baggetto, Loic; Carroll, Kyler J.; Hah, Hien -Yoong; ...

    2014-03-25

    Cycling Cu2Sb films with fluoroethylene carbonate additive drastically improves the capacity retention of the electrode compared to cycling in pure PC with about 250 mAh g-1 retained capacity for about two hundred cycles. TEM photographs reveal that the pristine films are formed of nanoparticles of 5-20 nm diameters. XRD results highlight that during the first discharge the reaction leads to the formation of Na3Sb via an intermediate amorphous phase. During charge, Na3Sb crystallites convert into an amorphous phase, which eventually crystallizes into Cu2Sb at full charge, indicating a high degree of structural reversibility. The subsequent discharge is marked by amore » new plateau around 0.5 V at low Na/Sb content which does not correspond to the formation of a crystalline phase. XAS data show that the fully discharged electrode material has interatomic distances matching those expected for the coexistence of Cu and Na3Sb nanodomains. At 1 V charge, the structure somewhat differs from that of Cu2Sb whereas at 2 V charge, when all Na is removed, the structure is significantly closer to that of the starting material. 121Sb Mössbauer spectroscopy isomer shifts of Cu2Sb powder (-9.67 mm s-1) and thin films (-9.65 mm s-1) are reported for the first time, and agree with the value predicted theoretically. At full discharge, an isomer shift (-8.10 mm s-1) rather close to that of a Na3Sb reference powder (-8.00 mm s-1) is measured, in agreement with the formation of Na3Sb domains evidenced by XRD and XAS data. As a result, the isomer shift at 1 V charge (-9.29 mm s-1) is close to that of the pristine material and the higher value is in agreement with the lack of full desodiation at 1 V.« less

  14. Structural and optical characterization of thermally evaporated bismuth and antimony films for photovoltaic applications

    NASA Astrophysics Data System (ADS)

    Srimathy, N.; Ruban Kumar, A.

    2016-05-01

    In this present study, the thin film of bismuth and antimony is coated by thermal evaporation system equipped with the inbuilt ultra high vacuum system. XRD analysis confirmed the rhombohedral structure of Bismuth and Antimony on the prepared film. The surface roughness and physical appearance is analyzed by Atomic force microscopy. The results of Raman Spectroscopy show the wave functions and the spectrum of electrons. The preparation technique and conditions strongly influence the crystalline structure and the phase composition of bismuth and antimony thin films. The electrical and optical properties for the prepared film are analyzed. The results show a great interest and promising applications in Photovoltaic devices.

  15. Anthropogenic impacts on the biogeochemistry and cycling of antimony.

    PubMed

    Shotyk, William; Krachler, Michael; Chen, Bin

    2005-01-01

    Antimony is a potentially toxic trace element with no known biological function. Antimony is commonly enriched in coals, and fossil fuel combustion appears to be the largest single source of anthropogenic Sb to the global atmosphere. Abundant in sulfide minerals, its emission to the atmosphere from anthropogenic activities is linked to the mining and metallurgy of non-ferrous metals, especially Pb, Cu, and Zn. In particular, the geochemical and mineralogical association of Sb with Pb minerals implies that, like Pb, Sb has been emitted to the environment for thousands of years because of Pb mining, smelting, and refining. In the US alone, there are more than 400 former secondary lead smelting operations and worldwide there are 133 Pb-Zn smelters in operation today. Antimony is used in creating and improving dozens of industrial and commercial materials including various alloys, ceramics, glasses, plastics, and synthetic fabrics, making waste incineration another important source of Sb to the environment. Enrichments of Sb in atmospheric aerosols, plants, soils, sediments, as well as alpine and polar snow and ice suggest that Sb contamination is extensive, but there are very few quantitative studies of the geographic extent, intensity, and chronology of this contamination. There is an urgent need to quantify the extent of human impacts and how these have changed with time. The decreasing inventories of anthropogenic Sb with time in peat cores from Switzerland and Scotland suggest that the atmospheric Sb flux may be declining, but there have been too few studies to make any general conclusions. In fact, some studies of sediments and biomonitors in central Europe show little decline in Sb concentrations during the past decades. There is an obvious need for reliable data from well dated archives such as polar snow and ice, peat bogs, and sediments. The air concentrations, extent of enrichment, particle size distribution, and rate of deposition of Sb in urban areas is

  16. Biogeochemistry of Antimony(V) in Microcosms under Sulfidogenic Conditions

    NASA Astrophysics Data System (ADS)

    O'Loughlin, E. J.; Johnson, C. R.; Antonopoulos, D. A.; Boyanov, M.; Flynn, T. M.; Koval, J. C.; Kemner, K. M.

    2015-12-01

    As the mining and use of antimony continues to increase, environmental concerns involving the element have grown. Antimony(V) and (III) are the two most environmentally-relevant oxidation states, but little is known about the redox transitions between the two in natural systems. To better understand the behavior of antimony in anoxic environments, we examined the transformations of Sb(V) under Fe(III)- and sulfate-reducing conditions in aqueous suspensions that contained 2 mM KSb(OH)6, 50 mM Fe(III) (as ferrihydrite), 10 mM sulfate, and 10 mM lactate, and were inoculated with sediment from a wetland on the campus of Argonne National Laboratory in Argonne, Illinois. Samples were collected over time to track changes in the concentrations of Sb, Fe(II), sulfate, and lactate, as well as the composition of the microbial community as determined by 16S rRNA gene inventories. We also examined the interaction of Sb(V) with pure Fe(II) mineral phases in aqueous suspensions containing 2 mM KSb(OH)6 and 50 mM Fe(II) as either magnetite, sideritre, vivianite, green rust, or mackinawite. X-ray absorption fine-structure spectroscopy was used to determine the valence state of Sb and its chemical speciation. Lactate was rapidly fermented to acetate and propionate concomittant with a bloom of Veillonellaceae. Utilization of propionate for dissimilatory sulfate reduction (DSR) was accompanied by an increase in Desulfobulbaceae. Sb K-edge X-Ray absorption near edge structure (XANES) analysis showed reduction of Sb(V) to Sb(III) within 4 weeks, concurrent with DSR and the formation of FeS. We observed variable responses in the ability of specific Fe(II) minerals to reduce Sb(V). No reduction was observed with magnetite, siderite, vivianite, or green rust. In the presence of mackinawite (FeS), however, Sb(V) was reduced to Sb(III) sulfide. These results suggest that the reduction of Sb(V) to Sb(III) is not likely under solely Fe(III)-reducing conditions, but is expected in sulfidogenic

  17. Synthesis and characterisation of nano-pore antimony imprinted polymer and its use in the extraction and determination of antimony in water and fruit juice samples.

    PubMed

    Shakerian, Farid; Dadfarnia, Shayessteh; Haji Shabani, Ali Mohammad; Nili Ahmad Abadi, Maryam

    2014-02-15

    A solid phase extraction method using antimony ion imprinted polymer (IIP) sorbent combined with electrothermal atomic absorption spectrometry (ETAAS) was developed for the extraction and speciation of antimony. The sorbent has been synthesised in the presence of Sb(III) and ammonium pyrrolidine dithiocarbamate (APDC) using styrene as the monomer and ethylene glycol dimethacrylate (EGDMA) as the cross linker. The imprinted Sb(III) ions were removed by leaching with HCl (50%v/v) and the polymer was characterised by FT-IR and scanning electron microscopy. The maximum sorption capacity of the IIP for Sb(III) ions was found to be 6.7 mg g(-1). With preconcentration of 60 mL of sample, an enhancement factor of 232 and detection limit of 3.9 ng L(-1) was obtained. Total antimony was determined after the reduction of Sb(V) to Sb(III). The method was successfully applied to the determination of antimony species in water samples and total antimony in fruit juices.

  18. Ornithine decarboxylase or gamma-glutamylcysteine synthetase overexpression protects Leishmania (Vianna) guyanensis against antimony.

    PubMed

    Fonseca, Maisa S; Comini, Marcelo A; Resende, Bethânia V; Santi, Ana Maria M; Zoboli, Antônio P; Moreira, Douglas S; Murta, Silvane M F

    2017-04-01

    Trypanosomatids present a unique mechanism for detoxification of peroxides that is dependent on trypanothione (bisglutathionylspermidine). Ornithine decarboxylase (ODC) and γ-glutamylcysteine synthetase (GSH1) produce molecules that are direct precursors of trypanothione. In this study, Leishmania guyanensis odc and gsh1 overexpressor cell lines were generated to investigate the contribution of these genes to the trivalent antimony (Sb(III))-resistance phenotype. The ODC- or GSH1-overexpressors parasites presented an increase of two and four-fold in Sb(III)-resistance index, respectively, when compared with the wild-type line. Pharmacological inhibition of ODC and GSH1 with the specific inhibitors α-difluoromethylornithine (DFMO) and buthionine sulfoximine (BSO), respectively, increased the antileishmanial effect of Sb(III) in all cell lines. However, the ODC- and GSH1-overexpressor were still more resistant to Sb(III) than the parental cell line. Together, our data shows that modulation of ODC and GSH1 levels and activity is sufficient to affect L. guyanensis susceptibility to Sb(III), and confirms a role of these genes in the Sb(III)-resistance phenotype.

  19. Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy.

    PubMed

    Allan, Phoebe K; Griffin, John M; Darwiche, Ali; Borkiewicz, Olaf J; Wiaderek, Kamila M; Chapman, Karena W; Morris, Andrew J; Chupas, Peter J; Monconduit, Laure; Grey, Clare P

    2016-02-24

    Operando pair distribution function (PDF) analysis and ex situ (23)Na magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from (23)Na ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electrochemically; a-Na(3-x)Sb (x ≈ 0.4-0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na(1.7)Sb, a highly amorphous structure featuring some Sb-Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na(3-x)Sb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphous network reacts at higher voltages reforming a-Na(1.7)Sb, then a-Na(3-x)Sb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na(3-x)Sb without the formation of a-Na(1.7)Sb. a-Na(3-x)Sb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature (23)Na NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes.

  20. Silicon quantum dots with counted antimony donor implants

    NASA Astrophysics Data System (ADS)

    Singh, Meenakshi; Pacheco, Jose; Perry, Daniel; Wendt, Joel; Manginell, Ronald; Dominguez, Jason; Pluym, Tammy; Luhman, Dwight; Bielejec, Edward; Lilly, Michael; Carroll, Malcolm

    Antimony donor implants next to silicon quantum dots have been detected with integrated solid-state diode detectors with single ion precision. Devices with counted number of donors have been fabricated and low temperature transport measurements have been performed. Charge offsets, indicative of donor ionization and coupling to the quantum dot, have been detected in these devices. The number of offsets corresponds to 10-50% of the number of donors counted. We will report on tunneling time measurements and spin readout measurements on the donor offsets. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE Office of Basic Energy Sciences user facility. The work was supported by Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

  1. Copper, lead, zinc, antimony, and arsenic in Pakistan

    USGS Publications Warehouse

    White, Max Gregg

    1975-01-01

    Copper localities that merit geological investigation are found in the western Chasai District, in North Waziristan Agency, and in the Salt Range in Mianwali and Sargodha Districts. No high-grade deposits have been .reported from these ,areas and if deposits are developed they will likely be low-grade, high-tonnage, disseminated deposits. Those localities reported from Chitral State are too remote and inaccessible to be of interest now. All lead localities found to date are of minor importance; there has been small production at one .locality in Chasai District and in the southern part of the Hazara District. Zinc, antimony, and arsenic are sparse in Pakistan and no important localities of these metals are reported.

  2. Coherent and incoherent structural dynamics in laser-excited antimony

    NASA Astrophysics Data System (ADS)

    Waldecker, Lutz; Vasileiadis, Thomas; Bertoni, Roman; Ernstorfer, Ralph; Zier, Tobias; Valencia, Felipe H.; Garcia, Martin E.; Zijlstra, Eeuwe S.

    2017-02-01

    We investigate the excitation of phonons in photoexcited antimony and demonstrate that the entire electron-lattice interactions, in particular coherent and incoherent electron-phonon coupling, can be probed simultaneously. Using femtosecond electron diffraction (FED) with high temporal resolution, we observe the coherent excitation of the fully symmetric A1 g optical phonon mode via the shift of the minimum of the atomic potential energy surface. Ab initio molecular dynamics simulations on laser excited potential energy surfaces are performed to quantify the change in lattice potential and the associated real-space amplitude of the coherent atomic oscillations. Good agreement is obtained between the parameter-free calculations and the experiment. In addition, our experimental configuration allows observing the energy transfer from electrons to phonons via incoherent electron-lattice scattering events. The electron-phonon coupling is determined as a function of electronic temperature from our DFT calculations and the data by applying different models for the energy transfer.

  3. Metabolism of tellurium, antimony and germanium simultaneously administered to rats.

    PubMed

    Kobayashi, Akihiro; Ogra, Yasumitsu

    2009-06-01

    Recently, tellurium (Te), antimony (Sb) and germanium (Ge) have been used as an alloy in phase-change optical magnetic disks, such as digital versatile disk-random access memory (DVD-RAM) and DVD-recordable disk (DVD-RW). Although these metalloids, the so-called "exotic" elements, are known to be non-essential and harmful, little is known about their toxic effects and metabolism. Metalloid compounds, tellurite, antimonite and germanium dioxide, were simultaneously administered to rats. Their distributions metabolites were determined and identified by speciation. Te and Sb accumulated in red blood cells (RBCs): Te accumulated in RBCs in the dimethylated form, while Sb accumulated in the inorganic/non-methylated form. In addition, trimethyltelluronium (TMTe) was the urinary metabolite of Te, whereas Sb in urine was not methylated but oxidized. Ge was also not methylated in rats. These results suggest that each metalloid is metabolized via a unique pathway.

  4. Atomistic mechanisms governing structural stability change of zinc antimony thermoelectrics

    SciTech Connect

    Yang, Xiaolong; Lin, Jianping; Qiao, Guanjun; Wang, Zhao

    2015-01-05

    The structural stability of thermoelectric materials is a subject of growing importance for their energy harvesting applications. Here, we study the microscopic mechanisms governing the structural stability change of zinc antimony at its working temperature, using molecular dynamics combined with experimental measurements of the electrical and thermal conductivity. Our results show that the temperature-dependence of the thermal and electrical transport coefficients is strongly correlated with a structural transition. This is found to be associated with a relaxation process, in which a group of Zn atoms migrates between interstitial sites. This atom migration gradually leads to a stabilizing structural transition of the entire crystal framework, and then results in a more stable crystal structure of β–Zn{sub 4}Sb{sub 3} at high temperature.

  5. Geochemistries of arsenic, antimony, mercury, and related elements in sediments of puget sound

    USGS Publications Warehouse

    Crecelius, E.A.; Bothner, Michael H.; Carpenter, R.

    1975-01-01

    The natural distributions of arsenic, antimony mercury, chromium, cobalt, iron, aluminum, and carbon in the surface sediments of Puget Sound are perturbed by two major anthropogenic sources of trace metals: a copper smelter near Tacoma, Wash., that discharges large amounts of arsenic and antimony, and a chlor-alkali plant in Bellingham, Wash., which, in the recent past, discharged significant amounts of mercury. Arsenic and antimony inputs from the smelter over the past 80 years are evident in sediment cores whose accumulation rates have been determined by the lead-210 technique. An arsenic budget for Puget Sound reveals the importance of atmospheric input resulting from smokestack emissions of the smelter. Chemical extraction studies of sediments showed that more than 82% of the mercury was associated with easily oxidizable organic matter, whereas about 50% of both arsenic and antimony was associated with extractable iron and aluminum compounds.

  6. Concentrations of arsenic, antimony, and boron in steam and steam condensate at The Geysers, California

    USGS Publications Warehouse

    Smith, C.L.; Ficklin, W.H.; Thompson, J.M.

    1987-01-01

    Studies at The Geysers Geothermal Field, California indicate that under some circumstances elements that are transported in the vapor phase can become enriched in the liquid phase. Waters from two condensate traps (steam traps) on steam lines at The Geysers are enriched with arsenic, antimony, and boron compared to the concentrations of these elements in coexisting steam. Concentrations of boron in condensate-trap waters were as high as 160 mg/L, arsenic as high as 35 mg/L, and antimony as high as 200 ??g/L. Enrichment of arsenic, antimony, and boron is at least partially controlled by the partitioning of these elements into the liquid phase, according to their vapor-liquid distribution coefficients, after they are transported in steam. Several of the elements that are most soluble in steam, including arsenic and antimony, are part of the trace-element suite that characterizes precious-metal epithermal ore deposits. ?? 1987.

  7. Antimony Trioxide (ATO) - Summary of External Peer Review and Public Comments and Disposition

    EPA Pesticide Factsheets

    This document summarizes the public and external peer review comments that the EPA’s Office of Pollution Prevention and Toxics (OPPT) received for the draft work plan risk assessment for Antimony Trioxide (ATO).

  8. Genistein inhibition of OGD-induced brain neuron death correlates with its modulation of apoptosis, voltage-gated potassium and sodium currents and glutamate signal pathway.

    PubMed

    Ma, Xue-Ling; Zhang, Feng; Wang, Yu-Xiang; He, Cong-Cong; Tian, Kun; Wang, Hong-Gang; An, Di; Heng, Bin; Liu, Yan-Qiang

    2016-07-25

    In the present study, we established an in vitro model of hypoxic-ischemia via exposing primary neurons of newborn rats to oxygen-glucose deprivation (OGD) and observing the effects of genistein, a soybean isoflavone, on hypoxic-ischemic neuron viability, apoptosis, voltage-activated potassium (Kv) and sodium (Nav) currents, and glutamate receptor subunits. The results indicated that OGD exposure reduced the viability and increased the apoptosis of brain neurons. Meanwhile, OGD exposure caused changes in the current-voltage curves and current amplitude values of voltage-activated potassium and sodium currents; OGD exposure also decreased GluR2 expression and increased NR2 expression. However, genistein at least partially reversed the effects caused by OGD. The results suggest that hypoxic-ischemia-caused neuronal apoptosis/death is related to an increase in K(+) efflux, a decrease in Na(+) influx, a down-regulation of GluR2, and an up-regulation of NR2. Genistein may exert some neuroprotective effects via the modulation of Kv and Nav currents and the glutamate signal pathway, mediated by GluR2 and NR2.

  9. Survey of antimony workers: mortality 1961-1992.

    PubMed Central

    Jones, R D

    1994-01-01

    The mortality of a census population and a prospective cohort of men employed on an antimony smelter in the north east of England was followed up from 1961-1992. The workers studied were exposed to a variety of agents including antimony and its oxides, arsenic and arsenic oxides, sulphur dioxide, and polycyclic aromatic hydrocarbons. The regional mortality rates were used to calculate expected deaths and a group of zircon sand workers employed on the site were used as a comparison group. For the census population of men working on the smelter before 1961 a significant increase in deaths from lung cancer was found (32 observed v 14.7 expected, P < 0.001). A similar excess was seen among maintenance men (12 observed v 5.3 expected P = 0.016). No such excess was found in the cohort recruited after 1960 (5 observed v 9.2 expected, maintenance workers 3 observed v 2.8 expected). There was evidence of a minimum latency period of around 20 years between first exposure and death from lung cancer. No evidence was found for a correlation between length of time worked and mortality from lung cancer. The results show that an increased risk of lung cancer existed in the workers employed before 1961, but it was not possible to attribute this excess to any particular agent. Mortality analysed by five year calendar periods of first exposure show a lessening of effect after 1955. Although the power of the study is clearly less for more recent periods of exposure the absence of any excess in the population after 1960 is encouraging. PMID:7849856

  10. Can microorganisms convert antimony trioxide or potassium antimonyl tartrate to methylated stibines?

    PubMed

    Gates, P N; Harrop, H A; Pridham, J B; Smethurst, B

    1997-10-20

    No evidence could be found for the production, in culture, of methylated antimony compounds from water-insoluble or soluble antimony derivatives by the aerobes, Scopulariopsis brevicaulis or Bacillus sp. or by anaerobes associated with cot mattress materials. The study does not support the hypothesis that volatile organoantimony compounds are a cause of cot deaths. Anaerobic cultures from a polluted pond generated trimethylstibine from potassium antimonyl tartrate.

  11. Inhibition of phosphatidylserine synthesis during Jurkat T cell activation. The phosphatase inhibitor, sodium ortho-vanadate bypasses the CD3/T cell receptor-induced second messenger signaling pathway.

    PubMed

    Pelassy, C; Breittmayer, J P; Aussel, C

    2000-02-01

    Sodium ortho-vanadate (Na3VO4), an inhibitor of protein tyrosine phosphatase, induces a rapid (15 min) and strong inhibition of phosphatidylserine synthesis with an IC50 = 100 microM. The mode of action of Na3VO4 was compared to that of CD3 mAbs. It was found that Na3VO4 bypasses the major CD3-induced T cell activation signals including protein tyrosine phosphorylation, p56lck activation and the generation of second messengers including inositol phosphates and its subsequent Ca2+ mobilization as well as diacylglycerol production. These facts were confirmed by using a panel of Jurkat clones that differs by the expression of either tyrosine kinases involved in the CD3-induced T cell activation pathway such as p56lck, p72syk and ZAP-70 or some cell surface receptors such as the CD3/TCR complex or the CD45 phosphatase.

  12. Inhibition of hydrolytic enzymes by gold compounds. I. beta-Glucuronidase and acid phosphatase by sodium tetrachloroaurate (III) and potassium tetrabromoaurate (III).

    PubMed

    Lee, M T; Ahmed, T; Friedman, M E

    1989-01-01

    Purified bovine liver beta-glucuronidase (beta-D-glucuronide glucuronohydrolase, EC 3.2.1.32) and wheat germ acid phosphatase (orthophosphoric monoesterphosphohydrolase, EC 3.1.3.2) were inhibited with freshly dissolved and 24 h aquated tetrahaloaurate (III) compounds. Rate and equilibrium inhibition constants were measured. From this data two acid phosphatases species were observed. Equilibrium inhibition constants ranged from 1 to 12.5 microM for the various gold compounds toward both enzymes. The first order rate constants ranged between 0.005 and 0.04 min.-1 for most reactions with the exception of the fast reacting acid phosphatase which had values as high as 2.6 and 2.8 min.-1. It is observed that the beta-glucuronidase is rapidly inhibited during the equilibrium phase before the more slower reaction covalent bond formation takes place. The acid phosphatases form the covalent bonds more rapidly, especially the faster reacting species suggesting a unique difference in the active site geometry to that of the more slowly reacting species. The tightly bonded gold (III)-enzyme complex is probably the reason for its toxicity and non-anti-inflammatory use as a drug.

  13. Antimony accumulation in Achillea ageratum, Plantago lanceolata and Silene vulgaris growing in an old Sb-mining area.

    PubMed

    Baroni, F; Boscagli, A; Protano, G; Riccobono, F

    2000-08-01

    Preliminary data of a biogeochemical survey concerning antimony transfer from soil to plants in an abandoned Sb-mining area are presented. Achillea ageratum, Plantago lanceolata and Silene vulgaris can strongly accumulate antimony when its extractable fraction in the soil is high (139-793 mg/kg). A. ageratum accumulates in basal leaves (1367 mg/kg) and inflorescences (1105 mg/kg), P. lanceolata in roots (1150 mg/kg) and S. vulgaris in shoots (1164 mg/kg). In these plant species, the efficiency of antimony accumulation decreases when the antimony availability in the soil is high. In A. ageratum and S. vulgaris, the death of the epigeal target part at the end of the growing season contributes to a reduction of the antimony load in the plant. A study to test the use of these species as bioindicators of antimony availability in soil is suggested by our results.

  14. Glycine Betaine, Carnitine, and Choline Enhance Salinity Tolerance and Prevent the Accumulation of Sodium to a Level Inhibiting Growth of Tetragenococcus halophila

    PubMed Central

    Robert, Hervé; Le Marrec, Claire; Blanco, Carlos; Jebbar, Mohamed

    2000-01-01

    Natural-abundance 13C-nuclear magnetic resonance was used to probe the intracellular organic solute content of the moderately halophilic bacterium Tetragenococcus halophila. When grown in complex growth media supplemented or not with NaCl, T. halophila accumulates glycine betaine and carnitine. Unlike other moderate halophiles, T. halophila was not able to produce potent osmoprotectants (such as ectoines and glycine betaine) through de novo synthesis when cultured in defined medium under hyperosmotic constraint. Addition of 2 mM carnitine, glycine betaine, or choline to defined medium improved growth parameters, not only at high salinity (up to 2.5 M NaCl) but also in media lacking NaCl. These compounds were taken up when available in the surrounding medium. The transport activity occurred at low and high salinities and seems to be constitutive. Glycine betaine and carnitine were accumulated by T. halophila in an unmodified form, while exogenously provided choline led to an intracellular accumulation of glycine betaine. This is the first evidence of the existence of a choline-glycine betaine pathway in a lactic acid bacterium. An assay showed that the compatible solutes strikingly repressed the accumulation of glutamate and slightly increased the intracellular potassium level only at high salinity. Interestingly, osmoprotectant-treated cells were able to maintain the intracellular sodium concentration at a relatively constant level (200 to 300 nmol/mg [dry weight]), independent of the NaCl concentration of the medium. In contrast, in the absence of osmoprotectant, the intracellular sodium content increased sharply from 200 to 2,060 nmol/mg (dry weight) when the salinity of the medium was raised from 1 to 2 M. Indeed, the imported compatible solutes play an actual role in regulating the intracellular Na+ content and confer a much higher salt tolerance to T. halophila. PMID:10653711

  15. Aqueous extracts of two varieties of ginger (Zingiber officinale) inhibit angiotensin I-converting enzyme, iron(II), and sodium nitroprusside-induced lipid peroxidation in the rat heart in vitro.

    PubMed

    Akinyemi, Ayodele J; Ademiluyi, Adedayo O; Oboh, Ganiyu

    2013-07-01

    Ginger has reportedly been used in folk medicine for the management and prevention of hypertension and other cardiovascular diseases. Therefore, this study sought to investigate the inhibitory effect of aqueous extracts of two varieties of ginger on a key enzyme linked to hypertension (angiotensin I-converting enzyme [ACE]), and on pro-oxidants [Fe(2+) and sodium nitroprusside (SNP)] which have been shown to induce lipid peroxidation in the rat's isolated heart in vitro. Aqueous extracts (0.05 mg/mL) of red ginger (Zingiber officinale var. Rubra) and white ginger (Zingiber officinale Roscoe) were prepared and the ability of the extracts to inhibit ACE along with Fe(2+)- and SNP-induced lipid peroxidation was determined in rat's heart in vitro. Results revealed that both extracts inhibited ACE in a dose-dependent manner (25-125 μg/mL). However, red ginger extract (EC50=27.5 μg/mL) had a significantly (P<.05) higher inhibitory effect on ACE than white ginger extract (EC50=87.0 μg/mL). Furthermore, incubation of the rat's heart in the presence of Fe(2+) and SNP caused a significant increase (P<.05) in the malondialdehyde (MDA) content of the heart homogenates, while the introduction of the ginger extracts (78-313 μg/mL) caused a dose-dependent decrease in the MDA content of the stressed heart homogenates. This suggests that the possible mechanism through which ginger exerts its antihypertensive properties may be through inhibition of ACE activity and prevention of lipid peroxidation in the heart. Furthermore, red ginger showed stronger inhibition of ACE than white ginger. Additionally, it should be noted that these protective properties of the ginger varieties could be attributed to their polyphenol contents.

  16. SOLID-LIQUID PHASE EQUILIBRIUM IN BINARY SYSTEMS OF TRIPHENYL ANTIMONY WITH BIPHENYL, NAPHTHALENE, AND BENZOIC ACID.

    DTIC Science & Technology

    PHASE STUDIES, *ORGANOMETALLIC COMPOUNDS, SEMICONDUCTORS, SOLID STATE PHYSICS, ANTIMONY COMPOUNDS, EUTECTICS , ZONE MELTING, HALIDES, BISMUTH, ARSENIC, ELECTRONS, NAPHTHALENES , PHASE DIAGRAMS, SOLIDS.

  17. Simulation of antimony adsorption on nano-zero valent iron and kaolinite and analyzing the influencing parameters.

    PubMed

    Saeidnia, Setareh; Asadollahfardi, Gholamreza; Darban, Ahmad Khodadadi; Mohseni, Mehdi

    2016-01-01

    Antimony is one of the most toxic pollutants in industrial and mineral wastewaters threatening the life of humans and other creatures. We simulated the adsorption of antimony in the presence of nano-zero valent iron (nZVI) adsorbent, on kaolinite and in the presence of nZVI coated on kaolinite from mineral wastewater using VISUAL MINTEQ 3.1 software. Our aim was to determine the factors affecting the adsorption of antimony by applying simulation. The simulation was performed using an adsorption model of a diffuse layer model. The results of the simulation indicated that the nZVI concentration, initial concentrations of antimony and pH factor are effective on the adsorption of antimony. In the conducted stimulation, the optimum pH was 2-5 and the highest adsorption occurred in an acidic state. With increasing initial concentrations of antimony in the simulation, we concluded that nZVI had absorbed various concentrations above 90% and, by increasing the concentration of nZVI, antimony adsorption rate increased. The increased surface area of nZVI and the expansion of more interchangeable surfaces available for reaction with antimony ions causes more antimony ions to be adsorbed. In all cases, the coefficient of determination between the laboratory results and the model predictions that was obtained was more than 0.9.

  18. Stimulation and inhibition of the sodium pump by cardioactive steroids in relation to their binding sites and their inotropic effect on guinea-pig isolated atria.

    PubMed

    Ghysel-Burton, J; Godfraind, T

    1979-06-01

    1 The actions of ouabain, ouabagenin and dihydroouabain on the contractility and on the ionic content have been investigated in left guinea-pig atria stimulated at 3.3 Hz. The specific binding of ouabain and its displacement by the other cardenolides have been determined. 2 The action of either ouabain or ouabagenin on Na and K content was qualitatively different according to the concentration employed. Low doses evoked a reduction of Nai whereas high doses produced an increase. Dihydroouabain evoked only a Nai gain. 3 The increase of KCl concentration from 2.7 to 12 mM decreased Nai in untreated atria and displaced ouabain dose-effect curves to the right. 4 ED50 values for the positive inotropic effect were lower than ED50 values for the inhibition of the pump and were not similarly affected by an increase in KCl concentration. 5 The specific binding of ouabain occurred at high and low affinity sites, related to Na pump stimulation and inhibition respectively. 6 The increase in KCl reduced the affinity of the two groups of sites for ouabain and increased the capacity of the high-affinity sites whereas the capacity of the other sites remained unchanged. 7 The results confirm the existence of two specific binding sites for ouabain in guinea-pig heart and suggest that the inhibition of the Na pump is not the only mechanism responsible for the positive inotropic effect of cardiac glycosides.

  19. Stimulation and inhibition of the sodium pump by cardioactive steroids in relation to their binding sites and their inotropic effect on guinea-pig isolated atria.

    PubMed Central

    Ghysel-Burton, J.; Godfraind, T.

    1979-01-01

    1 The actions of ouabain, ouabagenin and dihydroouabain on the contractility and on the ionic content have been investigated in left guinea-pig atria stimulated at 3.3 Hz. The specific binding of ouabain and its displacement by the other cardenolides have been determined. 2 The action of either ouabain or ouabagenin on Na and K content was qualitatively different according to the concentration employed. Low doses evoked a reduction of Nai whereas high doses produced an increase. Dihydroouabain evoked only a Nai gain. 3 The increase of KCl concentration from 2.7 to 12 mM decreased Nai in untreated atria and displaced ouabain dose-effect curves to the right. 4 ED50 values for the positive inotropic effect were lower than ED50 values for the inhibition of the pump and were not similarly affected by an increase in KCl concentration. 5 The specific binding of ouabain occurred at high and low affinity sites, related to Na pump stimulation and inhibition respectively. 6 The increase in KCl reduced the affinity of the two groups of sites for ouabain and increased the capacity of the high-affinity sites whereas the capacity of the other sites remained unchanged. 7 The results confirm the existence of two specific binding sites for ouabain in guinea-pig heart and suggest that the inhibition of the Na pump is not the only mechanism responsible for the positive inotropic effect of cardiac glycosides. PMID:465868

  20. Sodium azide

    Integrated Risk Information System (IRIS)

    Sodium azide ; CASRN 26628 - 22 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Ef

  1. Acifluorfen, sodium

    Integrated Risk Information System (IRIS)

    Acifluorfen , sodium ; CASRN 62476 - 59 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcino

  2. Sodium cyanide

    Integrated Risk Information System (IRIS)

    Jump to main content . Integrated Risk Information System Recent Additions | Contact Us Search : All EPA IRIS • You are here : EPA Home • Research • Environmental Assessment • IRIS • IRIS Summaries Redirect Page As of September 28 , 2010 , the assessment summary for sodium cyanide is included in the

  3. Sodium diethyldithiocarbamate

    Integrated Risk Information System (IRIS)

    Sodium diethyldithiocarbamate ; CASRN 148 - 18 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Non

  4. Sodium fluoroacetate

    Integrated Risk Information System (IRIS)

    Sodium fluoroacetate ; CASRN 62 - 74 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogen

  5. Synergistic and complete reversal of the multidrug resistance of mitoxantrone hydrochloride by three-in-one multifunctional lipid-sodium glycocholate nanocarriers based on simultaneous BCRP and Bcl-2 inhibition

    PubMed Central

    Ling, Guixia; Zhang, Tianhong; Zhang, Peng; Sun, Jin; He, Zhonggui

    2016-01-01

    Multidrug resistance (MDR) is a severe obstacle to successful chemotherapy due to its complicated nature that involves multiple mechanisms, such as drug efflux by transporters (P-glycoprotein and breast cancer resistance protein, BCRP) and anti-apoptotic defense (B-cell lymphoma, Bcl-2). To synergistically and completely reverse MDR by simultaneous inhibition of pump and non-pump cellular resistance, three-in-one multifunctional lipid-sodium glycocholate (GcNa) nanocarriers (TMLGNs) have been designed for controlled co-delivery of water-soluble cationic mitoxantrone hydrochloride (MTO), cyclosporine A (CsA – BCRP inhibitor), and GcNa (Bcl-2 inhibitor). GcNa and dextran sulfate were incorporated as anionic compounds to enhance the encapsulation efficiency of MTO (up to 97.8%±1.9%) and sustain the release of cationic MTO by electrostatic interaction. The results of a series of in vitro and in vivo investigations indicated that the TMLGNs were taken up by the resistant cancer cells by an endocytosis pathway that escaped the efflux induced by BCRP, and the simultaneous release of CsA with MTO further efficiently inhibited the efflux of the released MTO by BCRP; meanwhile GcNa induced the apoptosis process, and an associated synergistic antitumor activity and reversion of MDR were achieved because the reversal index was almost 1.0. PMID:27601896

  6. Inhibition and Promotion of Heat-Induced Gelation of Whey Proteins in the Presence of Calcium by Addition of Sodium Caseinate.

    PubMed

    Nguyen, Bach T; Balakrishnan, Gireeshkumar; Jacquette, Boris; Nicolai, Taco; Chassenieux, Christophe; Schmitt, Christophe; Bovetto, Lionel

    2016-11-14

    Heat-induced aggregation and gelation of aqueous solutions of whey protein isolate (WPI) in the presence of sodium caseinate (SC) and CaCl2 was studied at pH 6.6. The effect of adding SC (0-100 g/L) on the structure of the aggregates and the gels was investigated by light scattering and confocal laser scanning microscopy at different CaCl2 concentration ([CaCl2] = 0-30 mM). The gelation process was studied by oscillatory shear rheology. At the whey protein concentrations studied here (34 and 60 g/L), no gels were formed in the absence of CaCl2 and SC. However, WPI solutions gelled above a critical CaCl2 concentration that increased with increasing SC concentration. In the absence of CaCl2, WPI gels were formed only above a critical SC concentration. The critical SC concentration needed to induce WPI gelation decreased weakly when CaCl2 was added. In an intermediate range of CaCl2 concentrations, gels were formed both at low and high SC concentrations, but not at intermediate SC concentrations. Finally, at high CaCl2 concentrations gels were formed at all SC concentrations. The gelation rate and the gel structure of the gels formed at low and high casein concentrations were very different. The effect of SC on the thermal gelation of WPI was interpreted by competition for Ca(2+), a chaperon effect, and microphase separation.

  7. Sustained inhibition of the NaV1.7 sodium channel by engineered dimers of the domain II binding peptide GpTx-1.

    PubMed

    Murray, Justin K; Biswas, Kaustav; Holder, J Ryan; Zou, Anruo; Ligutti, Joseph; Liu, Dong; Poppe, Leszek; Andrews, Kristin L; Lin, Fen-Fen; Meng, Shi-Yuan; Moyer, Bryan D; McDonough, Stefan I; Miranda, Les P

    2015-11-01

    Many efforts are underway to develop selective inhibitors of the voltage-gated sodium channel NaV1.7 as new analgesics. Thus far, however, in vitro selectivity has proved difficult for small molecules, and peptides generally lack appropriate pharmacokinetic properties. We previously identified the NaV1.7 inhibitory peptide GpTx-1 from tarantula venom and optimized its potency and selectivity via structure-guided analoging. To further understand GpTx-1 binding to NaV1.7, we have mapped the binding site to transmembrane segments 1-4 of the second pseudosubunit internal repeat (commonly referred to as Site 4) using NaV1.5/NaV1.7 chimeric protein constructs. We also report that select GpTx-1 amino acid residues apparently not contacting NaV1.7 can be derivatized with a hydrophilic polymer without adversely affecting peptide potency. Homodimerization of GpTx-1 with a bifunctional polyethylene glycol (PEG) linker resulted in a compound with increased potency and a significantly reduced off-rate, demonstrating the ability to modulate the function and properties of GpTx-1 by linking to additional molecules.

  8. Dead Nano-Sized Lactobacillus plantarum Inhibits Azoxymethane/Dextran Sulfate Sodium-Induced Colon Cancer in Balb/c Mice.

    PubMed

    Lee, Hyun Ah; Kim, Hyunung; Lee, Kwang-Won; Park, Kun-Young

    2015-12-01

    The chemopreventive effects of dead nano-sized Lactobacillus plantarum (nLp) on colon carcinogenesis, induced by dextran sulfate sodium and azoxymethane, were evaluated using Balb/c mice and compared with the effects of pure live L. plantarum (pLp). nLp is a dead shrunken form of L. plantarum derived from kimchi and has a particle size of 0.5-1.0 μm. Animals fed nLp showed less weight loss, longer colons, lower colon weight/length ratios, and fewer colonic tumors compared with pLp. In addition, the administration of nLp significantly reduced the expression of inflammatory markers, mediated the expression of cell cycle and apoptotic markers in colon tissues, and elevated fecal IgA levels more than pLp. Accordingly, the present study shows that the anticolorectal cancer activities of nLp are greater than those of pLp and suggests this is due to the suppression of inflammation, the induction of cell cycle arrest and apoptosis, and enhanced IgA secretion.

  9. Sodium houttuyfonate and EDTA-Na₂ in combination effectively inhibits Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans in vitro and in vivo.

    PubMed

    Huang, Weifeng; Duan, Qiangjun; Li, Fang; Shao, Jing; Cheng, Huijuan; Wu, Daqiang

    2015-01-01

    Sodium houttuyfonate (SH) has been found to be mildly anti-pathogenetic against the planktonic and biofilm phenotypes of Pseudomonas aeruginosa. Here, we have attempted to investigate further the anti-pathogenicity of SH and EDTA-Na₂ in combination and in vitro and in vivo against planktonic and biofilm phenotypes of Pseudomonas aeruginosa (16 strains), Staphylococcus aureus (13 strains) and Candida albicans (13 strains). The antimicrobial activity of SH against all three pathogens increased dramatically when it was combined with EDTA-Na₂, in vitro. Toxic reactions to the drugs when administered orally were insignificant in mice; no abnormalities were observed in the internal organs, such as the lungs and kidneys. Finally, the results of in vivo studies indicate that SH could extend the lifespan of infected animals when administered in combination with EDTA-Na2. Therefore, the results of the present study lead us to suggest that SH could be a promising antimicrobial agent and that SH combined with EDTA-Na₂ has the potential to be an excellent choice of drug for combating bacterial infections clinically.

  10. Sodium-bicarbonate cotransporter NBCn1/Slc4a7 inhibits NH4Cl-mediated inward current in Xenopus oocytes.

    PubMed

    Lee, Soojung; Choi, Inyeong

    2011-08-01

    The electroneutral Na(+)-HCO(3)(-) cotransporter NBCn1 (SLC4A7) contributes to intracellular pH maintenance and transepithelial HCO(3)(-) movement. In this study, we expressed NBCn1 in Xenopus oocytes and examined the effect of NBCn1 on oocyte NH(4)(+) transport by analysing changes in membrane potential, current and intracellular pH mediated by NH(4)Cl. In the presence of HCO(3)(-)/CO(2), applying NH(4)Cl (20 mm) produced intracellular acidification of oocytes. The acidification was faster in oocytes expressing NBCn1 than in control oocytes injected with water; however, NH(4)Cl-mediated membrane depolarization was smaller in oocytes expressing NBCn1. In HCO(3)(-)/CO(2)-free solution, NH(4)Cl produced a smaller inward current in NBCn1-expressing oocytes (56% inhibition by 20 mm NH(4)Cl, measured at --60 mV), while minimally affecting intracellular acidification. The inhibition of the current by NBCn1 was unaffected when BaCl(2) replaced KCl. Current-voltage relationships showed a positive and nearly linear relationship between NH(4)Cl-mediated current and voltage, which was markedly reduced by NBCn1. Large basal currents (before NH(4)Cl exposure) were produced in NBCn1-expressing oocytes owing to the previously characterized channel-like activity of NBCn1. Inhibiting this channel-like activity by Na(+) removal abolished the inhibitory effect of NBCn1 on NH(4)Cl-mediated currents. The currents were progressively reduced over 72-120 h after NBCn1 cRNA injection, during which the channel-like activity was high. These results indicate that NBCn1 stimulates NH(4)(+) transport by its Na(+)-HCO(3)(-) cotransport activity, while reducing NH(4)(+) conductance by its channel-like activity.

  11. Development of a high-affinity peptide that prevents phospholemman (PLM) inhibition of the sodium/calcium exchanger 1 (NCX1).

    PubMed

    Wanichawan, Pimthanya; Hodne, Kjetil; Hafver, Tandekile Lubelwana; Lunde, Marianne; Martinsen, Marita; Louch, William Edward; Sejersted, Ole Mathias; Carlson, Cathrine Rein

    2016-08-01

    NCX1 (Na(+)/Ca(2+) exchanger 1) is an important regulator of intracellular Ca(2+) and a potential therapeutic target for brain ischaemia and for diastolic heart failure with preserved ejection fraction. PLM (phospholemman), a substrate for protein kinases A and C, has been suggested to regulate NCX1 activity. However, although several studies have demonstrated that binding of phosphorylated PLM (pSer(68)-PLM) leads to NCX1 inhibition, other studies have failed to demonstrate a functional interaction of these proteins. In the present study, we aimed to analyse the biological function of the pSer(68)-PLM-NCX1 interaction by developing high-affinity blocking peptides. PLM was observed to co-fractionate and co-immunoprecipitate with NCX1 in rat left ventricle, and in co-transfected HEK (human embryonic kidney)-293 cells. For the first time, the NCX1-PLM interaction was also demonstrated in the brain. PLM binding sites on NCX1 were mapped to two regions by peptide array assays, containing the previously reported PASKT and QKHPD motifs. Conversely, the two NCX1 regions bound identical sequences in the cytoplasmic domain of PLM, suggesting that NCX1-PASKT and NCX1-QKHPD might bind to each PLM monomer. Using two-dimensional peptide arrays of the native NCX1 sequence KHPDKEIEQLIELANYQVLS revealed that double substitution of tyrosine for positions 1 and 4 (K1Y and D4Y) enhanced pSer(68)-PLM binding 8-fold. The optimized peptide blocked binding of NCX1-PASKT and NCX1-QKHPD to PLM and reversed PLM(S68D) inhibition of NCX1 activity (both forward and reverse mode) in HEK-293 cells. Altogether our data indicate that PLM interacts directly with NCX1 and inhibits NCX1 activity when phosphorylated at Ser(68).

  12. Development of a high-affinity peptide that prevents phospholemman (PLM) inhibition of the sodium/calcium exchanger 1 (NCX1)

    PubMed Central

    Wanichawan, Pimthanya; Hodne, Kjetil; Hafver, Tandekile Lubelwana; Lunde, Marianne; Martinsen, Marita; Louch, William Edward; Sejersted, Ole Mathias; Carlson, Cathrine Rein

    2016-01-01

    NCX1 (Na+/Ca2+ exchanger 1) is an important regulator of intracellular Ca2+ and a potential therapeutic target for brain ischaemia and for diastolic heart failure with preserved ejection fraction. PLM (phospholemman), a substrate for protein kinases A and C, has been suggested to regulate NCX1 activity. However, although several studies have demonstrated that binding of phosphorylated PLM (pSer68-PLM) leads to NCX1 inhibition, other studies have failed to demonstrate a functional interaction of these proteins. In the present study, we aimed to analyse the biological function of the pSer68-PLM–NCX1 interaction by developing high-affinity blocking peptides. PLM was observed to co-fractionate and co-immunoprecipitate with NCX1 in rat left ventricle, and in co-transfected HEK (human embryonic kidney)-293 cells. For the first time, the NCX1–PLM interaction was also demonstrated in the brain. PLM binding sites on NCX1 were mapped to two regions by peptide array assays, containing the previously reported PASKT and QKHPD motifs. Conversely, the two NCX1 regions bound identical sequences in the cytoplasmic domain of PLM, suggesting that NCX1-PASKT and NCX1-QKHPD might bind to each PLM monomer. Using two-dimensional peptide arrays of the native NCX1 sequence KHPDKEIEQLIELANYQVLS revealed that double substitution of tyrosine for positions 1 and 4 (K1Y and D4Y) enhanced pSer68-PLM binding 8-fold. The optimized peptide blocked binding of NCX1-PASKT and NCX1-QKHPD to PLM and reversed PLM(S68D) inhibition of NCX1 activity (both forward and reverse mode) in HEK-293 cells. Altogether our data indicate that PLM interacts directly with NCX1 and inhibits NCX1 activity when phosphorylated at Ser68. PMID:27247424

  13. Solid substrate-room temperature phosphorimetry for the determination of trace terbutaline sulfate based on its inhibition oxidation of rhodamine 6G by sodium periodate.

    PubMed

    Liu, Jia-Ming; Gao, Fei; Gao, Wen-Yan; Zeng, Li-Qing; Huang, Xiao-Mei; Li, Zhi-Ming; Huang, Xiu-Chai; Lin, Wei-Nv; Wang, Fang-Mei; Nie, Chang-Ling

    2008-03-01

    When 1.00 mol l(-1) I(-) is used as ion perturber, rhodamine 6G (Rh 6G) can emit strong and stable room temperature phosphorescence (RTP) on filter paper substrate in KHC(8)H(4)O(4)-HCl buffer solution (pH = 3.50), heated at 70 degrees C for 10 min. NaIO(4) can oxidize Rh 6G, which makes the RTP signal quench. Terbutaline sulfate (TBS) can inhibit NaIO(4) from oxidizing Rh 6G, which makes the RTP signal of Rh 6G enhance sharply. The content of TBS is linear correlation to DeltaIp of the system. Based on the facts above, a new inhibition solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace TBS has been established. The linear range of this method is 0.0104-2.08 pg spot(-1) (corresponding concentration: 0.026-5.2 ng ml(-1), with a sample volume of 0.4 microl) with a detection limit (L.D.) of 2.6 fg spot(-1) (corresponding concentration: 6.5 x 10(-12) g ml(-1)), and the regression equation of working curve is DeltaIp = 2.040 + 54.54 m(TBS) (pg spot(-1)), n = 6, correlation coefficient is 0.9994. For the samples containing 0.0104 pg spot(-1) and 2.08 pg spot(-1) TBS, the relative standard deviation (RSD) are 3.8% and 2.3% (n = 8), respectively, indicating good precision. This method has been applied to determination of trace TBS in the practical samples with satisfactory results. The reaction mechanism of NaIO(4) oxidizing Rh 6G to inhibit SS-RTP for the determination of trace TBS is also discussed.

  14. New Antimony Lanthanide Disulfide Dibromides LnSbS

    SciTech Connect

    Gout, D.; Jobic, S.; Evain, M.; Brec, R.

    2001-05-01

    CeSbS{sub 2}Br{sub 2} (I), Ce{sub 1/2}La{sub 1/2}SbS{sub 2}Br{sub 2} (II), and LaSbS{sub 2}Br{sub 2} (III) have been synthesized at 700 C from a mixture of LnBr{sub 3}, Ln{sub 2}S{sub 3}, Sb, and S and characterized by single-crystal X-ray diffraction. The three phases are isostructural (space group P2{sub 1}/c, Z=4) and crystallize in a novel, dense, bidimensional structure with cell parameters a=8.709(3) {angstrom}, b=9.187(2) {angstrom}, c=17.397(5) {angstrom} {beta}=104.26(3) for I, a=8.739(7) {angstrom}, b=9.219(7) {angstrom}, c=17.41(2) {angstrom}, =104.3(1) for II, and a=8.785(1) {angstrom}, b=9.236(2) {angstrom}, c=17.372(3) {angstrom}, {beta}=104.09(2) for III. In these compounds, [Ln S{sub 5}Br{sub 4}] and [Ln S{sub 3}Br{sub 6}] (Ln=Ce, La) distorted tricapped trigonal prisms define infinite {sub {infinity}}{sup 2}[LnS{sub 2}Br{sub 2}] layers counterbalanced and capped by antimony cations. In good accordance with the structural features, the charge balance in these materials is to be written Ln{sup III}Sb{sup III}S{sup -II}{sub 2}Br{sup -I}{sub 2}. These compounds exhibit a yellow hue with a measured absorption threshold of 2.42(1), 2.55(1), and 2.72(1) eV for I, II, and III, respectively. In the two cerium containing bromothioantimonates I and II, the origin of the color is assigned to a Ce-4f{yields}Ce-5d electronic transition, which shifts to higher energy from I to II due either to a matrix effect (increase of the mean Ln-S distances under the substitution of Ce for La) or to an atomic ordering between Ce and La cations on the Ln(1) and Ln(2) crystallographic sites. In contrast, the electronic transition at play in III involves a charge transfer from the bromine and sulfur ions to the antimony ions, the latter contributing substantially to the lowermost levels of the conduction band.

  15. Lactate rescues neuronal sodium homeostasis during impaired energy metabolism

    PubMed Central

    Karus, Claudia; Ziemens, Daniel; Rose, Christine R

    2015-01-01

    Recently, we established that recurrent activity evokes network sodium oscillations in neurons and astrocytes in hippocampal tissue slices. Interestingly, metabolic integrity of astrocytes was essential for the neurons' capacity to maintain low sodium and to recover from sodium loads, indicating an intimate metabolic coupling between the 2 cell types. Here, we studied if lactate can support neuronal sodium homeostasis during impaired energy metabolism by analyzing whether glucose removal, pharmacological inhibition of glycolysis and/or addition of lactate affect cellular sodium regulation. Furthermore, we studied the effect of lactate on sodium regulation during recurrent network activity and upon inhibition of the glial Krebs cycle by sodium-fluoroacetate. Our results indicate that lactate is preferentially used by neurons. They demonstrate that lactate supports neuronal sodium homeostasis and rescues the effects of glial poisoning by sodium-fluoroacetate. Altogether, they are in line with the proposed transfer of lactate from astrocytes to neurons, the so-called astrocyte-neuron-lactate shuttle. PMID:26039160

  16. Test Your Sodium Smarts

    MedlinePlus

    ... You may be surprised to learn how much sodium is in many foods. Sodium, including sodium chloride ... foods with little or no salt. Test your sodium smarts by answering these 10 questions about which ...

  17. Levels and risk factors of antimony contamination in human hair from an electronic waste recycling area, Guiyu, China.

    PubMed

    Huang, Yue; Ni, Wenqing; Chen, Yaowen; Wang, Xiaoling; Zhang, Jingwen; Wu, Kusheng

    2015-05-01

    The primitive electronic waste (e-waste) recycling has brought a series of environmental pollutants in Guiyu, China. Antimony is one of the important metal contaminants and has aroused the global concerns recently. We aimed to investigate concentrations of antimony in human hair from Guiyu and compared them with those from a control area where no e-waste recycling exists, and assessed the potential risk factors. A total of 205 human hair samples from Guiyu and 80 samples from Jinping were collected for analysis. All volunteers were asked to complete a questionnaire including socio-demographic characteristics and other possible factors related to hair antimony exposure. The concentrations of hair antimony were analyzed using atomic absorption spectrophotometer. Our results indicated that the level of hair antimony in volunteers from Guiyu (median, 160.78; range, 6.99-4412.59 ng/g) was significantly higher than those from Jinping (median, 61.74; range, 2.98-628.43 ng/g). The residents who engaged in e-waste recycling activities in Guiyu had higher hair antimony concentrations than others (P < 0.001). There was no significant difference of hair antimony concentrations among different occupation types in e-waste recycling. Multiple stepwise regression analysis indicated that hair antimony concentrations were associated with education level (β = -0.064), the time of residence in Guiyu (β = 0.112), living house also served as e-waste workshop (β = 0.099), the work related to e-waste (β = 0.169), and smoking (β = 0.018). The elevated hair antimony concentrations implied that the residents in Guiyu might be at high risk of antimony contamination, especially the e-waste recycling workers. Work related to e-waste recycling activities and long-time residence in Guiyu contributed to the high hair antimony exposure.

  18. mTOR Inhibition Attenuates Dextran Sulfate Sodium-Induced Colitis by Suppressing T Cell Proliferation and Balancing TH1/TH17/Treg Profile

    PubMed Central

    Wang, Yilin; Wang, Zhengting; Pei, Yaofei; Fan, Rong; Liu, Xiqiang; Wang, Lei; Zhou, Jie; Zheng, Sichang; Zhang, Tianyu; Lin, Yun; Zhang, Maochen; Tao, Ran; Zhong, Jie

    2016-01-01

    It has been established that mammalian target of Rapamycin (mTOR) inhibitors have anti-inflammatory effects in models of experimental colitis. However, the underlying mechanism is largely unknown. In this research, we investigate the anti-inflammatory effects of AZD8055, a potent mTOR inhibitor, on T cell response in dextran sulfate sodium (DSS)-induced colitis in mice, a commonly used animal model of inflammatory bowel diseases (IBD). Severity of colitis is evaluated by changing of body weight, bloody stool, fecal consistency, histology evaluation and cytokine expression. We find that AZD8055 treatment attenuates DSS-induced body weight loss, colon length shortening and pathological damage of the colon. And AZD8055 treatment decreases colonic expression of genes encoding the pro-inflammatory cytokines interferon-γ, interleukin (IL)-17A, IL-1β,IL-6 and tumor necrosis factor(TNF)-a and increases colonic expression of anti-inflammatory cytokines IL-10. We show that AZD8055 treatment decreases the percentages of CD4+ T cells and CD8+ T cells in spleen, lymph nodes and peripheral blood of mice. We also find that AZD8055 treatment significantly reduces the number of T helper 1(TH1) cells and TH17 cells and increases regulatory T (Treg) cells in the lamina propria and mesenteric lymph nodes. Furthermore, we demonstrates that AZD8055 suppresses the proliferation of CD4+ and CD8+ T cells and the differentiation of TH1/TH17 cells and expands Treg cells in vitro. The results suggest that, in experimental colitis, AZD8055 exerts anti-inflammatory effect by regulating T helper cell polarization and proliferation. PMID:27128484

  19. A study of the inhibition/promotion effects of sodium-copper chlorophyllin (SCC)-mediated mutagenesis in somatic cells of Drosophila.

    PubMed

    Pimentel, E; Cruces, M P; Zimmering, S

    2011-05-18

    Sodium-copper chlorophyllin (SCC), a copper-porphyrin complex, has been shown to act as an inhibitor as well as a promoter of DNA-damage induction by a variety of mutagens in several test systems. In order to investigate the basis of this dual effect, experiments were carried out to compare the influence of pretreatment with intact SCC and that of its constituents, the metal-free protoporphyrin (PP-IX) and copper as CuCl(2). The wing-spot test was employed to monitor mutational events in somatic cells of Drosophila melanogaster. Heterozygous mwh+/+flr(3) larvae were treated for 24h with SCC, PP-IX, CuCl(2) or sucrose. Following this treatment, one group of larvae were immediately allowed to feed on instant medium containing 0.5mM N-nitroso-N-ethylurea (ENU) dissolved in phosphate buffer to reach pH 6. The remaining larvae received treatment with ENU with a delay of 1, 2 or 3days (DTD). Results revealed an (a) overall inhibitory effect for 0-DTD and 1-DTD after pretreatment with SCC, (b) only in 0-DTD after PP-IX, and (c) in all DTDs after treatment with CuCl(2). These results provide evidence that the copper ion plays a central role in the antimutagenic effect of SCC, and for a sustained period of time. Pretreatment with SCC and PP-IX produced a promoter effect at 2-DTD and 3-DTD. The results could be explained as an effect of the accumulation of metal-free porphyrin following the dissociation of the copper-porphyrin complex (SCC), the copper-ion reaching proteins to form complexes and participated in anabolic pathways.

  20. Determination of antimony by using tungsten trap atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Titretir, Serap; Kendüzler, Erdal; Arslan, Yasin; Kula, İbrahim; Bakırdere, Sezgin; Ataman, O. Yavuz.

    2008-08-01

    An electrically heated tungsten coil was used as a trap in the determination of antimony. The technique consists of three steps. Initially, SbH 3 is formed by hydride generation procedure; then the analyte species in vapor form are transported to W-coil trap heated at 370 °C. Following the preconcentration step, the trap is heated to 895 °C; analyte species are revolatilized and transported to the flame-heated quartz atom cell where atomization and the formation of signal take place. The experimental parameters were optimized both for trap and no-trap studies. The most important experimental parameters are concentrations of HCl and NaBH 4 solutions, H 2 and Ar gas flow rates, and collection and revolatilization temperatures of W-coil. Accuracy was tested using a certified reference material, waste water EU-L-1. Limit of detection for the system is 16 ng l - 1 using a sample of 36 ml collected in 4.0 min. Enhancement factor in sensitivity was 17.

  1. Calcium-Antimony Alloys as Electrodes for Liquid Metal Batteries

    SciTech Connect

    Ouchi, T; Kim, H; Ning, XH; Sadoway, DR

    2014-08-08

    The performance of a calcium-antimony (Ca-Sb) alloy serving as the positive electrode in a Ca vertical bar vertical bar Sb liquid metal battery was investigated in an electrochemical cell, Ca(in Bi) vertical bar LiCl-NaCl-CaCl2 vertical bar Ca(in Sb). The equilibrium potential of the Ca-Sb electrode was found to lie on the interval, 1.2-0.95 V versus Ca, in good agreement with electromotive force (emf) measurements in the literature. During both alloying and dealloying of Ca at the Sb electrode, the charge transfer and mass transport at the interface are facile enough that the electrode potential varies linearly from 0.95 to 0.75 V vs Ca(s) as current density varies from 50 to 500 mA cm(-2). The discharge capacity of the Ca vertical bar vertical bar Sb cells increases as the operating temperature increases due to the higher solubility and diffusivity of Ca in Sb. The cell was successfully cycled with high coulombic efficiency (similar to 100%) and small fade rate (<0.01% cycle(-1)). These data combined with the favorable costs of these metals and salts make the Ca vertical bar vertical bar Sb liquid metal battery attractive for grid-scale energy storage. (C) The Author(s) 2014. Published by ECS. All rights reserved.

  2. Increased metacyclogenesis of antimony-resistant Leishmania donovani clinical lines.

    PubMed

    Ouakad, M; Vanaerschot, M; Rijal, S; Sundar, S; Speybroeck, N; Kestens, L; Boel, L; De Doncker, S; Maes, I; Decuypere, S; Dujardin, J-C

    2011-09-01

    Mathematical models predict that the future of epidemics of drug-resistant pathogens depends in part on the competitive fitness of drug-resistant strains. Considering metacyclogenesis (differentiation process essential for infectivity) as a major contributor to the fitness of Leishmania donovani, we tested its relationship with pentavalent antimony (SbV) resistance in clinical lines. Different methods for the assessment of metacyclogenesis were cross-validated: gene expression profiling (META1 and SHERP), morphometry (microscopy and FACS), in vitro infectivity to macrophages and resistance to complement lysis. This was done on a model constituted by 2 pairs of reference strains cloned from a SbV-resistant and -sensitive isolate. We selected the most adequate parameter and extended the analysis of metacyclogenesis diversity to a sample of 20 clinical lines with different in vitro susceptibility to the drug. The capacity of metacyclogenesis, as measured by the complement lysis test, was shown to be significantly higher in SbV-resistant clinical lines of L. donovani than in SbV-sensitive lines. Together with other lines of evidence, it is concluded that L. donovani constitutes a unique example and model of drug-resistant pathogens with traits of increased fitness. These findings raise a fundamental question about the potential risks of selecting more virulent pathogens through massive chemotherapeutic interventions.

  3. Mitochondrial Proteomics of Antimony and Miltefosine Resistant Leishmania infantum

    PubMed Central

    Vincent, Isabel M.; Racine, Gina; Légaré, Danielle; Ouellette, Marc

    2015-01-01

    Antimony (SbIII) and miltefosine (MIL) are important drugs for the treatment of Leishmania parasite infections. The mitochondrion is likely to play a central role in SbIII and MIL induced cell death in this parasite. Enriched mitochondrial samples from Leishmania promastigotes selected step by step for in vitro resistance to SbIII and MIL were subjected to differential proteomic analysis. A shared decrease in both mutants in the levels of pyruvate dehydrogenase, dihydrolipoamide dehydrogenase, and isocitrate dehydrogenase was observed, as well as a differential abundance in two calcium-binding proteins and the unique dynamin-1-like protein of the parasite. Both mutants presented a shared increase in the succinyl-CoA:3-ketoacid-coenzyme A transferase and the abundance of numerous hypothetical proteins was also altered in both mutants. In general, the proteomic changes observed in the MIL mutant were less pronounced than in the SbIII mutant, probably due to the early appearance of a mutation in the miltefosine transporter abrogating the need for a strong mitochondrial adaptation. This study is the first analysis of the Leishmania mitochondrial proteome and offers powerful insights into the adaptations to this organelle during SbIII and MIL drug resistance. PMID:28248274

  4. Antimony bioavailability: knowledge and research perspectives for sustainable agricultures.

    PubMed

    Pierart, Antoine; Shahid, Muhammad; Séjalon-Delmas, Nathalie; Dumat, Camille

    2015-05-30

    The increasing interest in urban agriculture highlights the crucial question of crop quality. The main objectives for environmental sustainability are a decrease in chemical inputs, a reduction in the level of pollutants, and an improvement in the soil's biological activity. Among inorganic pollutants emitted by vehicle traffic and some industrial processes in urban areas, antimony (Sb) is observed on a global scale. While this metalloid is known to be potentially toxic, it can transfer from the soil or the atmosphere to plants, and accumulate in their edible parts. Urban agriculture is developing worldwide, and could therefore increasingly expose populations to Sb. The objective of this review was in consequences to gather and interpret actual knowledge of Sb uptake and bioaccumulation by crops, to reveal investigative fields on which to focus. While there is still no legal maximal value for Sb in plants and soils, light has to be shed on its accumulation and the factors affecting it. A relative absence of data exists about the role of soil flora and fauna in the transfer, speciation and compartmentation of Sb in vegetables. Moreover, little information exists on Sb ecotoxicity for terrestrial ecosystems. A human risk assessment has finally been reviewed, with particular focus on Sb bioaccessibility.

  5. Thermal Stability of Nanocrystalline Copper Alloyed with Antimony

    NASA Astrophysics Data System (ADS)

    Atwater, Mark A.; Mula, Suhrit; Scattergood, Ronald O.; Koch, Carl C.

    2013-12-01

    Nanocrystalline copper (Cu) was generated by cryogenic, high-energy ball milling. Antimony (Sb) was added to investigate its utility in stabilizing the grain structure during annealing up to a maximum temperature of 1073 K (800 °C). When alloyed with Sb in quantities up to 1 at. pct, thermal stability was maintained up to 673 K (400 °C). Cu and Sb have very different molar volumes which can drive segregation of the solute due to the elastic strain energy and hence stabilize the grain size by reducing grain boundary energy. The elastic mismatch of Sb in Cu is calculated to be quite large (113 kJ/mol) when molar volume is used, but when an equivalent equation using atomic radius is applied, the driving force is nearly an order of magnitude lower (~12 kJ/mol). The low elastic mismatch is corroborated by the large equilibrium solubility of Sb in Cu. The results for the Cu-Sb system are compared to the nanocrystalline Ni-W system and the large amount of equilibrium solubility of the solute in both cases is thought to hinder thermal stabilization since segregation is not strongly favored.

  6. Yb3+/Ho3+-codoped antimony-silicate optical fiber

    NASA Astrophysics Data System (ADS)

    Żmojda, Jacek; Dorosz, Dominik; Kochanowicz, Marcin; Miluski, Piotr; Dorosz, Jan

    2012-05-01

    The emission properties of Yb3+/Ho3+-codoped antimony-silicate optical fiber has been investigated. Luminescence at 2.1 μm corresponding to 5I7--> 5I8 transition in holmium was obtained by energy transfer between Yb3+ and Ho3+ ions. According to the Dexter-Miyakawa model, the parameters of energy migration CDD of the 2F5/2 (Yb3+) <--> 2F5/2 (Yb3+) transition and direct energy transfer CDA of the 2F5/2 (Yb3+) --> 5I6 (Ho3+) transition was calculated. The optimization of the activator content and the concentration ratio were conducted with the purpose of maximizing the efficiency of energy transfer. It made possible to select best-suited glass which was used to manufacture double-clad optical fiber. Strong and narrow bands of spontaneous emission which formed as a result of energy transfer between ytterbium and holmium ions were observed in the fiber under exciting with radiation at 978 nm wavelength.

  7. Yb3+/Ho3+-codoped antimony-silicate optical fiber

    NASA Astrophysics Data System (ADS)

    Żmojda, Jacek; Dorosz, Dominik; Kochanowicz, Marcin; Miluski, Piotr; Dorosz, Jan

    The emission properties of Yb3+/Ho3+-codoped antimony-silicate optical fiber has been investigated. Luminescence at 2.1 μm corresponding to 5I7--> 5I8 transition in holmium was obtained by energy transfer between Yb3+ and Ho3+ ions. According to the Dexter-Miyakawa model, the parameters of energy migration CDD of the 2F5/2 (Yb3+) <--> 2F5/2 (Yb3+) transition and direct energy transfer CDA of the 2F5/2 (Yb3+) --> 5I6 (Ho3+) transition was calculated. The optimization of the activator content and the concentration ratio were conducted with the purpose of maximizing the efficiency of energy transfer. It made possible to select best-suited glass which was used to manufacture double-clad optical fiber. Strong and narrow bands of spontaneous emission which formed as a result of energy transfer between ytterbium and holmium ions were observed in the fiber under exciting with radiation at 978 nm wavelength.

  8. Porfimer-sodium (Photofrin-II) in combination with ionizing radiation inhibits tumor-initiating cell proliferation and improves glioblastoma treatment efficacy

    PubMed Central

    Benayoun, Liat; Schaffer, Moshe; Bril, Rotem; Gingis-Velitski, Svetlana; Segal, Ehud; Nevelsky, Alexsander; Satchi-Fainaro, Ronit; Shaked, Yuval

    2013-01-01

    Tumor relapse and tumor cell repopulation has been explained partially by the drug-free break period between successive conventional treatments. Strategies to overcome tumor relapse have been proposed, such as the use of chemotherapeutic drugs or radiation in small, frequent fractionated doses without an extended break period between treatment intervals. Yet, tumors usually acquire resistance and eventually escape the therapy. Several mechanisms have been proposed to explain the resistance of tumors to therapy, one of which involves the cancer stem cell or tumor-initiating cell (TIC) concept. TICs are believed to resist many conventional therapies, in part due to their slow proliferation and self-renewal capacities. Therefore, emerging efforts to eradicate TICs are being undertaken. Here we show that treatment with Photofrin II, among the most frequently used photosensitizers, sensitized a TIC-enriched U-87MG human glioblastoma cell to radiation, and improve treatment outcome when used in combination with radiotherapy. A U-87MG tumor cell population enriched with radiation-resistant TICs becomes radio-sensitive, and an inhibition of cell proliferation and an increase in apoptosis are found in the presence of Photofrin II. Furthermore, U-87MG tumors implanted in mice treated with Photofrin II and radiation exhibit a significant reduction in angiogenesis and vasculogenesis, and an increased percentage of apoptotic TICs when compared with tumors grown in mice treated with radiation alone. Collectively, our results offer a new possible explanation for the therapeutic effects of radiosensitizing agents, and suggest that combinatorial treatment modalities can effectively prolong treatment outcome of glioblastoma tumors by inhibiting tumor growth mediated by TICs. PMID:23114641

  9. Low sodium diet (image)

    MedlinePlus

    ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ... for you. Look for these words on labels: low-sodium, sodium-free, no salt added, sodium-reduced, or ...

  10. Electrochemical antimony removal from accumulator acid: results from removal trials in laboratory cells.

    PubMed

    Bergmann, M E Henry; Koparal, A Savas

    2011-11-30

    Regeneration of spent accumulator acid could be an alternative process for crystallization, neutralisation and disposal. Therefore, for the first time in a study of the possibilities of electrochemical removal of antimony and accumulator acid regeneration on a laboratory scale, two synthetic and several real systems containing sulfuric acid of concentrations ranging between 28% and 36%, and antimony species were tested. Discontinuous electrochemical reactors with anion exchange membranes were successfully used in these experiments, which were conducted at a temperature of 35°C. Removal of antimony using cells that were not divided by a separator, however, was not possible. In selected experiments, by varying the electrode material, type of electrolyte, and cell current, the concentration of antimony could be reduced from the range of 5 ppm to 0.15 ppm. This resulted in current efficiencies between 0.00002% and 0.001%, and in specific electroenergy demands between 100 Wh L(-1) and 2000 Wh L(-1). In other experiments on substances with antimony contents up to 3500 mg L(-1), the current efficiencies obtained were more than a thousandfold higher. In contrast to the formally high relative energy consumption parameters absolute demand parameters are relatively small and favour the electrochemical method in small scale application. Besides plate electrodes, 3D-cathodes were used. Copper- and graphite cathodes produced the best results.

  11. Electrolyte transport in distal colon of sodium-depleted rats: Effect of sodium repletion

    SciTech Connect

    Turnamian, S.G.; Binder, H.J. )

    1988-09-01

    Dietary sodium depletion increases plasma aldosterone level and, as a result, induces amiloride-sensitive electrogenic sodium absorption and electrogenic potassium secretion and stimulates Na{sup +}-K{sup +}-ATPase activity in rat distal colon, while inhibiting electroneutral sodium chloride absorption. To assess the events that occur as the aldosterone-stimulated colon reverts to normal, unidirectional {sup 22}Na and {sup 36}Cl fluxes were measured under voltage-clamp conditions across isolated distal colonic mucosa of rats that were initially dietary sodium depleted for 7 days and then sodium repleted for varying periods of time before the study. Within 8 h of dietary sodium repletion, plasma aldosterone level and Na{sup +}-K{sup +}-ATPase activity declined to normal, amiloride-sensitive electrogenic sodium absorption decreased by >90%, and active electrogenic potassium secretion also decreased markedly. In contrast, electroneutral sodium chloride absorption did not completely return to levels seen in normal animals until {approximately}64-68 h. These results demonstrate that maintenance of electrogenic sodium absorption and potassium secretion are directly dependent on elevated plasma aldosterone levels. The inhibition of electroneutral sodium absorption, although initiated by excess aldosterone, persists after normalization of the plasma aldosterone level, thereby implying that the inhibition is dependent on additional factor(s).

  12. First Report on Infant Acute Urticaria after Mother’s Parenteral Use of Meglumine Antimoniate (Glucantime): A Case Report

    PubMed Central

    MOZAFARI, Omid; SHOROFI, Seyed Afshin; YOUSEFI, Seyde Sedighe

    2016-01-01

    Pentavalent antimonials are still the first drug of choice for the treatment of cutaneous leishmaniasis (CL). Like other treatments, they can cause adverse reactions including musculoskeletal pain, gastrointestinal disturbances, and mild to moderate headaches. In this paper, we report the first case of an infant who developed acute urticaria after her mother’s parenteral use of meglumine antimoniate (glucantime). PMID:27957467

  13. Solution structure of delta-Am2766: a highly hydrophobic delta-conotoxin from Conus amadis that inhibits inactivation of neuronal voltage-gated sodium channels.

    PubMed

    Sarma, Siddhartha P; Kumar, G Senthil; Sudarslal, S; Iengar, Prathima; Ramasamy, P; Sikdar, Sujit K; Krishnan, K S; Balaram, Padmanabhan

    2005-04-01

    The three-dimensional (3D) NMR solution structure (MeOH) of the highly hydrophobic delta-conotoxin delta-Am2766 from the molluscivorous snail Conus amadis has been determined. Fifteen converged structures were obtained on the basis of 262 distance constraints, 25 torsion-angle constraints, and ten constraints based on disulfide linkages and H-bonds. The root-mean-square deviations (rmsd) about the averaged coordinates of the backbone (N, C(alpha), C) and (all) heavy atoms were 0.62+/-0.20 and 1.12+/-0.23 A, respectively. The structures determined are of good stereochemical quality, as evidenced by the high percentage (100%) of backbone dihedral angles that occupy favorable and additionally allowed regions of the Ramachandran map. The structure of delta-Am2766 consists of a triple-stranded antiparallel beta-sheet, and of four turns. The three disulfides form the classical 'inhibitory cysteine knot' motif. So far, only one tertiary structure of a delta-conotoxin has been reported; thus, the tertiary structure of delta-Am2766 is the second such example. Another Conus peptide, Am2735 from C. amadis, has also been purified and sequenced. Am2735 shares 96% sequence identity with delta-Am2766. Unlike delta-Am2766, Am2735 does not inhibit the fast inactivation of Na+ currents in rat brain Na(v)1.2 Na+ channels at concentrations up to 200 nM.

  14. SESPE-FRAZIER, DIABLO, MATILIJA, DRY LAKES, SAWMILL-BADLANDS, CUYAMA, ANTIMONY, AND QUATAL ROADLESS AREAS, CALIFORNIA.

    USGS Publications Warehouse

    Frizzell, Virgil A.; Hale, William N.

    1984-01-01

    The study area, consisting of the Sespe-Frazier, Diablo, Matilija, Dry Lakes, Sawmill-Badlands, Cuyama, Antimony, and Quatal Roadless Areas, occupies about 872 sq mi in the Los Padres National Forest, California. Studies indicate that the Sespe-Frazier Roadless Area contains demonstrated resources of gold, gypsum, phosphate and bentonite; deposits in the Cuyama Roadless Area have demonstrated resources of gypsum; mines in the Antimony Roadless Area have demonstrated resources of antimony, gold, silver, and marble; and the Quatal Roadless Area has demonstrated resources of bentonite. The Sespe-Frazier Roadless Area has substantiated potential for geothermal resources suitable for direct-heat purposes, probable and substantiated potential for oil and gas resources, and probable potential for gold resources. Small areas of probable resource potential for antimony and gold were identified in Antimony Roadless Area.

  15. Antimony mediated growth of high-density InAs quantum dots for photovoltaic cells

    SciTech Connect

    Tutu, F. K.; Wu, J.; Lam, P.; Tang, M.; Liu, H.; Miyashita, N.; Okada, Y.; Wilson, J.; Allison, R.

    2013-07-22

    We report enhanced solar cell performance using high-density InAs quantum dots. The high-density quantum dot was grown by antimony mediated molecular beam epitaxy. In-plane quantum dot density over 1 × 10{sup 11} cm{sup −2} was achieved by applying a few monolayers of antimony on the GaAs surface prior to quantum dot growth. The formation of defective large clusters was reduced by optimization of the growth temperature and InAs coverage. Comparing with a standard quantum dot solar cell without the incorporation of antimony, the high-density quantum dot solar cell demonstrates a distinct improvement in short-circuit current from 7.4 mA/cm{sup 2} to 8.3 mA/cm{sup 2}.

  16. Trophic transfer of arsenic and antimony in a freshwater ecosystem: a field study.

    PubMed

    Culioli, Julia-Laurence; Fouquoire, Aurélie; Calendini, Serge; Mori, Christophe; Orsini, Antoine

    2009-10-04

    The distribution of arsenic and antimony discharges related to a past mining activity in the Bravona River and its tributary, the Presa River, was investigated. We determined levels of arsenic and antimony in the water and the biota (bryophytes, benthic macroinvertebrates and fish), along a pollution gradient. Concentrations of metalloids downstream mining wastes were significantly higher than those in reference station sites. The pattern of accumulation of arsenic in the food chain decreased as follows: macroinvertebrates>bryophytes>water>fish tissues. For antimony, the lowest concentrations were found in water. The accumulation of metals in invertebrate taxa depends on their place in the food chain, their feeding behavior, and their specific habit (lenitophilic/rheophilic species). Concentrations of both metalloids decreased with increasing trophic level.

  17. Process for treating spent catalyst including antimony halides from chlorofluorocarbon production

    SciTech Connect

    Kalcevic, V.; McGahan, J.F.

    1988-06-14

    A process for treating spent catalyst from chlorofluorocarbon production is described wherein the catalyst includes antimony halides and undergoes hydrolysis in an aqueous medium to produce insoluble antimony compounds and fluoride ions. The process comprises hydrolyzing the catalyst in an aqueous solution of ferric chloride having a sufficient concentration of ferric ions to complex substantially all of the fluoride ions produced upon hydrolysis of the catalyst, neutralizing the reaction mass present following hydrolysis of the catalyst and complexing of the fluoride ions by contacting the reaction mass with an aqueous suspension of a compound selected from the class consisting of calcium hydroxide and magnesium hydroxide, and separating the insoluble antimony compounds from the neutralized reaction mass.

  18. Study of upscaling possibilities for antimony sulfide solid state sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Nikolakopoulou, Archontoula; Raptis, Dimitrios; Dracopoulos, Vasilios; Sygellou, Lamprini; Andrikopoulos, Konstantinos S.; Lianos, Panagiotis

    2015-03-01

    Solid state solar cells of inverted structure were constructed by successive deposition of nanoparticulate titania, antimony sulfide sensitizer and P3HT on FTO electrodes with PEDOT:PSS:Ag as counter electrode. Sensitized photoanode electrodes were characterized by XRD, Raman, XPS, FESEM and UV-vis. Small laboratory scale cells were first constructed and optimized. Functional cells were obtained by annealing the antimony sulfide film either in air or in inert atmosphere. High short-circuit currents were recorded in both cases with air-annealed sample producing more current but lower voltage. Small unit cells were combined to form cell modules. Connection of unit cells in parallel increased current but not proportionally to that of the unit cell. Connection in series preserved current and generated voltage multiplication. Cells were constructed and studied under ambient conditions, without encapsulation. The results encourage upscaling of antimony sulfide solar cells.

  19. Spectrophotometric procedure using rhodamine B for determination of submicrogram quantities of antimony in rocks

    USGS Publications Warehouse

    Schnepfe, M.M.

    1973-01-01

    A spectrophotometric procedure using Rhodamine B is given for the determination of antimony in mineralized rocks after its separation as stibine. A study of the Rhodamine B reaction points to the importance of the order of addition of reagents in enhancing sensitivity and increasing the stability of the system. The tolerance of some 26 elements is established for the overall procedure. Although the limit of determination is approximately 0??5 ppm Sb in a 0??2-g sample, the procedure is intended primarily for screening samples containing more than 1 ppm Sb. In pure solutions 0??1 ??g of antimony can be determined with a relative standard deviation of 25%. For >0??2 ??g of antimony a relative standard deviation of 15% or less can be expected. ?? 1973.

  20. Concentration transient analysis of antimony surface segregation during Si(100) molecular beam epitaxy

    NASA Technical Reports Server (NTRS)

    Markert, L. C.; Greene, J. E.; Ni, W.-X.; Hansson, G. V.; Sundgren, J.-E.

    1991-01-01

    Antimony surface segregation during Si(100) molecular beam epitaxy (MBE) was investigated at temperatures T(sub s) = 515 - 800 C using concentration transient analysis (CTA). The dopant surface coverage Theta, bulk fraction gamma, and incorporation probability sigma during MBE were determined from secondary-ion mass spectrometry depth profiles of modulation-doped films. Programmed T(sub s) changes during growth were used to trap the surface-segregated dopant overlayer, producing concentration spikes whose integrated area corresponds to Theta. Thermal antimony doping by coevaporation was found to result in segregation strongly dependent on T(sub s) with Theta(sub Sb) values up to 0.9 monolayers (ML): in films doped with Sb(+) ions accelerated by 100 V, Theta(sub Sb) was less than or equal to 4 x 10(exp -3) ML. Surface segregation of coevaporated antimony was kinematically limited for the film growth conditions in these experiments.

  1. Use of Antimony in the Treatment of Leishmaniasis: Current Status and Future Directions

    PubMed Central

    Haldar, Arun Kumar; Sen, Pradip; Roy, Syamal

    2011-01-01

    In the recent past the standard treatment of kala-azar involved the use of pentavalent antimonials Sb(V). Because of progressive rise in treatment failure to Sb(V) was limited its use in the treatment program in the Indian subcontinent. Until now the mechanism of action of Sb(V) is not very clear. Recent studies indicated that both parasite and hosts contribute to the antimony efflux mechanism. Interestingly, antimonials show strong immunostimulatory abilities as evident from the upregulation of transplantation antigens and enhanced T cell stimulating ability of normal antigen presenting cells when treated with Sb(V) in vitro. Recently, it has been shown that some of the peroxovanadium compounds have Sb(V)-resistance modifying ability in experimental infection with Sb(V) resistant Leishmania donovani isolates in murine model. Thus, vanadium compounds may be used in combination with Sb(V) in the treatment of Sb(V) resistance cases of kala-azar. PMID:22091408

  2. Future trends of global atmospheric antimony emissions from anthropogenic activities until 2050

    NASA Astrophysics Data System (ADS)

    Zhou, Junrui; Tian, Hezhong; Zhu, Chuanyong; Hao, Jiming; Gao, Jiajia; Wang, Yong; Xue, Yifeng; Hua, Shenbin; Wang, Kun

    2015-11-01

    This paper presents the scenario forecast of global atmospheric antimony (Sb) emissions from anthropogenic activities till 2050. The projection scenarios are built based on the comprehensive global antimony emission inventory for the period 1995-2010 which is reported in our previous study. Three scenarios are set up to investigate the future changes of global antimony emissions as well as their source and region contribution characteristics. Trends of activity levels specified as 5 primary source categories are projected by combining the historical trend extrapolation with EIA International energy outlook 2013, while the source-specific dynamic emission factors are determined by applying transformed normal distribution functions. If no major changes in the efficiency of emission control are introduced and keep current air quality legislations (Current Legislation scenario), global antimony emissions will increase by a factor of 2 between 2010 and 2050. The largest increase in Sb emissions is projected from Asia due to large volume of nonferrous metals production and waste incineration. In case of enforcing the pollutant emission standards (Strengthened Control scenario), global antimony emissions in 2050 will stabilize with that of 2010. Moreover, we can anticipate further declines in Sb emissions for all continents with the best emission control performances (Maximum Feasible Technological Reduction scenario). Future antimony emissions from the top 10 largest emitting countries have also been calculated and source category contributions of increasing emissions of these countries present significant diversity. Furthermore, global emission projections in 2050 are distributed within a 1° × 1°latitude/longitude grid. East Asia, Western Europe and North America present remarkable differences in emission intensity under the three scenarios, which implies that source-and-country specific control measures are necessary to be implemented for abating Sb emissions from

  3. Noninferiority of Miltefosine Versus Meglumine Antimoniate for Cutaneous Leishmaniasis in Children

    PubMed Central

    Rubiano, Luisa Consuelo; Miranda, María Consuelo; Muvdi Arenas, Sandra; Montero, Luz Mery; Rodríguez-Barraquer, Isabel; Garcerant, Daniel; Prager, Martín; Osorio, Lyda; Rojas, Maria Ximena; Pérez, Mauricio; Nicholls, Ruben Santiago

    2012-01-01

    Background. Children have a lower response rate to antimonial drugs and higher elimination rate of antimony (Sb) than adults. Oral miltefosine has not been evaluated for pediatric cutaneous leishmaniasis. Methods. A randomized, noninferiority clinical trial with masked evaluation was conducted at 3 locations in Colombia where Leishmania panamensis and Leishmania guyanensis predominated. One hundred sixteen children aged 2–12 years with parasitologically confirmed cutaneous leishmaniasis were randomized to directly observed treatment with meglumine antimoniate (20 mg Sb/kg/d for 20 days; intramuscular) (n = 58) or miltefosine (1.8–2.5 mg/kg/d for 28 days; by mouth) (n = 58). Primary outcome was treatment failure at or before week 26 after initiation of treatment. Miltefosine was noninferior if the proportion of treatment failures was ≤15% higher than achieved with meglumine antimoniate (1-sided test, α = .05). Results. Ninety-five percent of children (111/116) completed follow-up evaluation. By intention-to-treat analysis, failure rate was 17.2% (98% confidence interval [CI], 5.7%–28.7%) for miltefosine and 31% (98% CI, 16.9%–45.2%) for meglumine antimoniate. The difference between treatment groups was 13.8%, (98% CI, −4.5% to 32%) (P = .04). Adverse events were mild for both treatments. Conclusions. Miltefosine is noninferior to meglumine antimoniate for treatment of pediatric cutaneous leishmaniasis caused by Leishmania (Viannia) species. Advantages of oral administration and low toxicity favor use of miltefosine in children. Clinical Trial Registration. NCT00487253. PMID:22238470

  4. The effect of nedocromil sodium and sodium cromoglycate on antigen-induced bronchoconstriction in the Ascaris-sensitive monkey.

    PubMed Central

    Eady, R. P.; Greenwood, B.; Jackson, D. M.; Orr, T. S.; Wells, E.

    1985-01-01

    Nedocromil sodium inhibited the bronchoconstriction caused by antigen challenge in Ascaris-sensitive monkeys and in addition it prevented the release of histamine from mast cells lavaged from sensitive monkeys. Sodium cromoglycate was relatively inactive in both these systems. It is suggested that nedocromil sodium can stabilize both mucosal and connective tissue mast cells and may represent a new type of drug. PMID:2992657

  5. Inhibition of Inactive States of Tetrodotoxin-Sensitive Sodium Channels Reduces Spontaneous Firing of C-Fiber Nociceptors and Produces Analgesia in Formalin and Complete Freund’s Adjuvant Models of Pain

    PubMed Central

    Matson, David J.; Hamamoto, Darryl T.; Bregman, Howard; Cooke, Melanie; DiMauro, Erin F.; Huang, Liyue; Johnson, Danielle; Li, Xingwen; McDermott, Jeff; Morgan, Carrie; Wilenkin, Ben; Malmberg, Annika B.; McDonough, Stefan I.; Simone, Donald A.

    2015-01-01

    While genetic evidence shows that the Nav1.7 voltage-gated sodium ion channel is a key regulator of pain, it is unclear exactly how Nav1.7 governs neuronal firing and what biophysical, physiological, and distribution properties of a pharmacological Nav1.7 inhibitor are required to produce analgesia. Here we characterize a series of aminotriazine inhibitors of Nav1.7 in vitro and in rodent models of pain and test the effects of the previously reported “compound 52” aminotriazine inhibitor on the spiking properties of nociceptors in vivo. Multiple aminotriazines, including some with low terminal brain to plasma concentration ratios, showed analgesic efficacy in the formalin model of pain. Effective concentrations were consistent with the in vitro potency as measured on partially-inactivated Nav1.7 but were far below concentrations required to inhibit non-inactivated Nav1.7. Compound 52 also reversed thermal hyperalgesia in the complete Freund’s adjuvant (CFA) model of pain. To study neuronal mechanisms, electrophysiological recordings were made in vivo from single nociceptive fibers from the rat tibial nerve one day after CFA injection. Compound 52 reduced the spontaneous firing of C-fiber nociceptors from approximately 0.7 Hz to 0.2 Hz and decreased the number of action potentials evoked by suprathreshold tactile and heat stimuli. It did not, however, appreciably alter the C-fiber thresholds for response to tactile or thermal stimuli. Surprisingly, compound 52 did not affect spontaneous activity or evoked responses of Aδ-fiber nociceptors. Results suggest that inhibition of inactivated states of TTX-S channels, mostly likely Nav1.7, in the peripheral nervous system produces analgesia by regulating the spontaneous discharge of C-fiber nociceptors. PMID:26379236

  6. Mercury, arsenic, antimony, and selenium contents of sediment from the Kuskokwim River, Bethel, Alaska, USA

    USGS Publications Warehouse

    Belkin, H.E.; Sparck, H.M.

    1993-01-01

    The Kuskokwim River at Bethel, Alaska, drains a major mercury-antimony metallogenic province in its upper reaches and tributaries. Bethel (population 4000) is situated on the Kuskokwim floodplain and also draws its water supply from wells located in river-deposited sediment. A boring through overbank and floodplain sediment has provided material to establish a baseline datum for sediment-hosted heavy metals. Mercury (total), arsenic, antimony, and selenium contents were determined; aluminum was also determined and used as normalizing factor. The contents of the heavy metals were relatively constant with depth and do not reflect any potential enrichment from upstream contaminant sources. ?? 1993 Springer-Verlag.

  7. Composite thin-foil bandpass filter for EUV astronomy Titanium-antimony-titanium

    NASA Technical Reports Server (NTRS)

    Jelinsky, P.; Martin, C.; Kimble, R.; Bowyer, S.; Steele, G.

    1983-01-01

    Thin metallic foils of antimony and titanium have been investigated in an attempt to develop an EUV filter with a bandpass from 350 to 550 A. A composite filter has been developed composed of antimony sandwiched between two titanium foils. The transmissions of sample composite foils and of pure titanium foils from 130 to 1216 A are presented. The absorption coefficients of anatimony and titanium and the effect of titanium oxide on the transmission are derived. The composite filter has been found to be quite stable and mechanically rugged. Among other uses, the filter shows substantial promise for EUV astronomy.

  8. Growth, photosynthesis, and defense mechanism of antimony (Sb)-contaminated Boehmeria nivea L.

    PubMed

    Chai, Li-Yuan; Mubarak, Hussani; Yang, Zhi-Hui; Yong, Wang; Tang, Chong-Jian; Mirza, Nosheen

    2016-04-01

    Ramie (Boehmeria nivea L.) is the oldest cash fiber crop in China and is widely grown in antimony (Sb) mining areas. To evaluate the extent of Sb resistance and tolerance, the growth, tolerance index (TI), Sb content in plant parts and in Hoagland solution, bioaccumulation factor (BF), photosynthesis, and physiological changes in Sb-contaminated B. nivea (20, 40, 80, and 200 mg L(-1) Sb) grown hydroponically were investigated. The Sb tolerance and resistance of ramie were clearly revealed by growth inhibition, a TI between 13 and 99 %, non-significant changes in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (photosystem II (PSII)) and single-photon avalanche diode (SPAD) value, a significant increase in Sb in plant parts, BF >1, and an increase in catalase (CAT) and malondialdehyde (MDA) at 200 mg L(-1) Sb. Under increasing Sb stress, nearly the same non-significant decline in the maximum quantum efficiency of photosystem (F v /F m ), energy-harvesting efficiency (PSII), relative quantum yield of photosystem II (φPSII), and photochemical quenching (qP), except for F v /F m at 20 mg L(-1) Sb, were recorded. SPAD values for chlorophyll under Sb stress showed an increasing trend, except for a slight decrease, i.e., <2 %, than the control SPAD value at 200 mg L(-1) Sb. With a continuous increase in MDA, superoxide dismutase (SOD), peroxidase (POD), and CAT activities were suppressed under Sb addition up to 40 mg L(-1) Sb and the addition of Sb enhanced enzyme production at 80 and 200 mg L(-1) Sb. A continuous decrease in SOD, POD, and CAT up to 40 mg L(-1) Sb and enhancements at ≥80 mg L(-1), along with the continuous enhancement of MDA activity and inhibited biomass production, clearly reveal the roles of these enzymes in detoxifying Sb stress and the defense mechanism of ramie at 80 mg L(-1) Sb. Thus, B. nivea constitutes a promising candidate for Sb phytoremediation at mining sites.

  9. Antimony distribution and mobility in topsoils and plants (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa) from polluted Sb-mining areas in Extremadura (Spain).

    PubMed

    Murciego, A Murciego; Sánchez, A García; González, M A Rodríguez; Gil, E Pinilla; Gordillo, C Toro; Fernández, J Cabezas; Triguero, T Buyolo

    2007-01-01

    A study about topsoil antimony distribution and mobility from the soils to the biomass has been afforded in three abandoned Sb mining areas located at Extremadura. Physico-chemical characteristics of the soils and total antimony levels were measured in soils and autochthonous plant species (Cytisus striatus, Cistus ladanifer and Dittrichia viscosa). Comparison with corresponding values in reference areas isolated from the mining activities is discussed. Antimony mobility in the soils was estimated by measuring the water extractable fraction; low results were obtained for the three soil areas, with no statistical differences. Plant ability to accumulate antimony was estimated by use of plant accumulation coefficients (PAC). Seasonal (spring vs. autumn) effects on the antimony content in the plant species. Cytisus striatus from Mari Rosa mine presented antimony excluder characteristics, whereas Dittrichia viscosa specimens growing in San Antonio mine showed a significant antimony bioaccumulation.

  10. Pilot testing of sodium thiosulfate

    SciTech Connect

    Chang, J.C.S.; Brna, T.G.

    1986-11-01

    Pilot plant tests have been conducted to evaluate sodium thiosulfate as an oxidation inhibition additive in five lime/limestone slurry flue gas desulfurization processes. It was found that the oxidation rate of absorbed sulfur dioxide (SO)/sub 2/ was reduced by more than 50 percent in the presence of 100 to 200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

  11. Pilot testing of sodium thiosulfate

    SciTech Connect

    Chang, J.C.S.; Brna, T.G.

    1986-01-01

    The article gives results of pilot-plant tests to evaluate sodium thiosulfate as an oxidation-inhibition additive in five lime/limestone slurry flue-gas desulfurization processes. It was found that the oxidation rate of absorbed SO/sub 2/ was reduced by more than 50% in the presence of 100-200 ppm of thiosulfate ion in the scrubbing slurry. Calcium sulfate dihydrate (gypsum) scaling was eliminated and the unsaturated (with respect to gypsum) operation mode was maintained by the addition of sodium thiosulfate. Other benefits of sodium thiosulfate addition observed at the pilot plant included improvement in solids dewatering properties for limestone processes and improvement in SO/sub 2/ removal efficiency for magnesium-enhanced lime/limestone processes.

  12. Ionic requirements of proximal tubular sodium transport. II. Hydrogen ion.

    PubMed

    Green, R; Giebisch, G

    1975-11-01

    Simultaneous perfusion to proximal convoluted tubules and peritubular capillaries was used to study the effects of different perfusion fluids on sodium reabsorption and hydrogen secretion, which was calculated as bicarbonate reabsorption and titratable acid. Results show that sodium reabsorption was not tightly coupled to hydrogen secretion. Bicarbonate stimulates both sodium reabsorption and hydrogen secretion, but Tris stimulates only sodium reabsorption. Imposing an adverse chloride gradient across the proximal tubule (C1- peritubular greater than C1- luminal) decreased sodium reabsorption but did not diminish hydrogen secretion. Diamox inhibited both net sodium and hydrogen transport. It is concluded that there is not firm linkage between sodium reabsorption and hydrogen secretion and that bicarbonate probably stimulates sodium transport by a number of mechanisms, including an effect on the sodium transport unrelated to its ability to increase hydrogen ion secretion.

  13. Sodium and Food Sources

    MedlinePlus

    ... Disease Cholesterol High Blood Pressure Million Hearts® WISEWOMAN Sodium and Food Sources Recommend on Facebook Tweet Share ... food [PDF-867K] and how to reduce sodium. Sodium Reduction Is Challenging Types of food matter: More ...

  14. Electrodeposition and device incorporation of bismuth antimony nanowire arrays

    NASA Astrophysics Data System (ADS)

    Keyani, Jennifer

    Thermoelectric materials have the unique property where the application of a potential difference across the material results in the formation of a temperature gradient, and vice versa. There is continued interest in bulk thermoelectric materials for power generation and refrigeration applications, however these materials are not currently in widespread use due to their low conversion efficiency. It has been predicted that nanostructured thermoelectric materials will show enhanced performance over their bulk counterparts. In this study, bismuth antimony (Bi1-xSbx) nanowire arrays have been synthesized and assembled into devices in order to demonstrate an enhanced performance in nanostructured thermoelectric materials. Bi1-xSbx nanowire arrays were fabricated by potentiostatic electrodeposition into porous alumina templates from a dimethyl sulfoxide (DMSO) solution. The nanowire composition and texture were studied as a function of the electrodeposition conditions in order to maximize their thermoelectric performance. Energy dispersive spectrometry and electron microprobe analysis were used to study the nanowire composition as a function of the electroactive and non-electroactive species in solution. Texturing in the nanowire arrays was observed by X-ray diffraction and controlled by the applied voltage and presence of supporting electrolyte. The nanowire arrays were also optimized for device incorporation by maximizing the number of nanowires and minimizing their length distribution. The areal density of nanowire arrays was on the order of 1010 wires/cm2 due to the high density of pores in the alumina and the high degree to which those pores were filled with electrodeposited material. A narrow distribution of nanowire lengths was observed by scanning electron microscopy across millimeter-length portions of the arrays. A hybrid nanowire-bulk thermoelectric device was assembled after electrical contacts were electrodeposited over Bi1-xSbx nanowire arrays. Nickel was

  15. Mechanisms of antimony adsorption onto soybean stover-derived biochar in aqueous solutions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Limited mechanistic knowledge is available to understand how biochar interacts with trace elements that exist predominantly as oxoanions, such as antimony (Sb). Soybean stover biochars were produced at 300 degrees C (SBC300) and 700 degrees C (SBC700), and were characterized by BET, Boehm titration,...

  16. Contrasting role of antimony and bismuth dopants on the thermoelectric performance of lead selenide.

    PubMed

    Lee, Yeseul; Lo, Shih-Han; Chen, Changqiang; Sun, Hui; Chung, Duck-Young; Chasapis, Thomas C; Uher, Ctirad; Dravid, Vinayak P; Kanatzidis, Mercouri G

    2014-05-02

    Increasing the conversion efficiency of thermoelectric materials is a key scientific driver behind a worldwide effort to enable heat to electricity power generation at competitive cost. Here we report an increased performance for antimony-doped lead selenide with a thermoelectric figure of merit of ~1.5 at 800 K. This is in sharp contrast to bismuth doped lead selenide, which reaches a figure of merit of <1. Substituting antimony or bismuth for lead achieves maximum power factors between ~23-27 μW cm(-1) K(-2) at temperatures above 400 K. The addition of small amounts (~0.25 mol%) of antimony generates extensive nanoscale precipitates, whereas comparable amounts of bismuth results in very few or no precipitates. The antimony-rich precipitates are endotaxial in lead selenide, and appear remarkably effective in reducing the lattice thermal conductivity. The corresponding bismuth-containing samples exhibit smaller reduction in lattice thermal conductivity.

  17. Nanostructured Carbon/Antimony Composites as Anode Materials for Lithium-Ion Batteries with Long Life.

    PubMed

    Cheng, Yong; Yi, Zheng; Wang, Chunli; Wang, Lidong; Wu, Yaoming; Wang, Limin

    2016-08-05

    A series of nanostructured carbon/antimony composites have been successfully synthesized by a simple sol-gel, high-temperature carbon thermal reduction process. In the carbon/antimony composites, antimony nanoparticles are homogeneously dispersed in the pyrolyzed nanoporous carbon matrix. As an anode material for lithium-ion batteries, the C/Sb10 composite displays a high initial discharge capacity of 1214.6 mAh g(-1) and a reversible charge capacity of 595.5 mAh g(-1) with a corresponding coulombic efficiency of 49 % in the first cycle. In addition, it exhibits a high reversible discharge capacity of 466.2 mAh g(-1) at a current density of 100 mA g(-1) after 200 cycles and a high rate discharge capacity of 354.4 mAh g(-1) at a current density of 1000 mA g(-1) . The excellent cycling stability and rate discharge performance of the C/Sb10 composite could be due to the uniform dispersion of antimony nanoparticles in the porous carbon matrix, which can buffer the volume expansion and maintain the integrity of the electrode during the charge-discharge cycles.

  18. Dismantling and chemical characterization of spent Peltier thermoelectric devices for antimony, bismuth and tellurium recovery.

    PubMed

    Balva, Maxime; Legeai, Sophie; Garoux, Laetitia; Leclerc, Nathalie; Meux, Eric

    2017-04-01

    Major uses of thermoelectricity concern refrigeration purposes, using Peltier devices, mainly composed of antimony, bismuth and tellurium. Antimony was identified as a critical raw material by EU and resources of bismuth and tellurium are not inexhaustible, so it is necessary to imagine the recycling of thermoelectric devices. That for, a complete characterization is needed, which is the aim of this work. Peltier devices were manually dismantled in three parts: the thermoelectric legs, the alumina plates on which remain the electrical contacts and the silicone paste used to connect the plates. The characterization was performed using five Peltier devices. It includes mass balances of the components, X-ray diffraction analysis of the thermoelectric legs and elemental analysis of each part of the device. It appears that alumina represents 45% of a Peltier device in weight. The electrical contacts are mainly composed of copper and tin, and the thermoelectric legs of bismuth, tellurium and antimony. Thermoelectric legs appear to be Se-doped Bi2Te3 and (Bi0,5Sb1,5)Te3 for n type and p type semiconductors, respectively. This work shows that Peltier devices can be considered as a copper ore and that thermoelectric legs contain high amounts of bismuth, tellurium and antimony compared to their traditional resources.

  19. Human biomonitoring of arsenic and antimony in case of an elevated geogenic exposure.

    PubMed Central

    Gebel, T W; Suchenwirth, R H; Bolten, C; Dunkelberg, H H

    1998-01-01

    Part of the northern Palatinate region in Germany is characterized by elevated levels of arsenic and antimony in the soil due to the presence of ore sources and former mining activities. In a biomonitoring study, 218 residents were investigated for a putative increased intake of these elements. Seventy-six nonexposed subjects in a rural region in south lower Saxony were chosen as the reference group. Urine and scalp hair samples were obtained as surrogates to determine the internal exposures to arsenic and antimony. The analyses were performed using graphite furnace atomic absorption spectrometry except for arsenic in urine, which was determined by the hydride technique. This method does not detect organoarsenicals from seafood, which are not toxicologically relevant. In the northern Palatinate subjects, slightly elevated arsenic contents in urine and scalp hair (presumably not hazardous) could be correlated with an increased arsenic content in the soil. On the other hand, the results did not show a correlation between the antimony contents in the soil of the housing area and those in urine and hair. Except for antimony in scalp hair, age tended to be associated with internal exposures to arsenic and antimony in both study groups. Consumption of seafood had a slight impact on the level of urinary arsenic, which is indicative of the presence of low quantities of inorganic arsenicals and dimethylarsinic acid in seafood. The arsenic and antimony contents in scalp hair were positively correlated with the 24-hr arsenic excretion in urine. However, antimony in scalp hair was not correlated with seafood consumption as was arsenic in scalp hair and in urine. This indicated the existence of unidentified common pathways of exposure contributing to the alimentary body burden. Short time peaks in the 24-hr excretion of arsenic in urine, which could not be assigned to a high consumption of seafood, were detected for six study participants. This suggests that additional factors

  20. Sodium toxicity in methanogenic systems: Rates and modeling

    SciTech Connect

    Yerkes, D.W.; Speece, R.E.

    1998-07-01

    In this paper, the mechanisms of sodium toxicity in methane producing anaerobic wastewater treatment systems are explored. Kinetic parameters for acetate uptake and sodium inhibition are determined. Methanosarcina enrichment cultures were used to determine a sodium inhibition constant, K{sub i}, of 295 mM. Methanosarcina showed complete acclimation to 500 mM Na{sup +} within 120 days. It is demonstrated that anaerobic systems have the ability to adapt over several weeks to very high concentrations of sodium, although the rate of methane production is slowed dramatically.

  1. Fondaparinux sodium.

    PubMed

    Reverter, J C

    2002-03-01

    Fondaparinux (Org-31540 / SR-90107A) is a new drug chemically synthesized for treatment and prophylaxis of thromboembolic disease. Fondaparinux is a selective inhibitor of activated factor X. Its structure is the copy of the heparin pentasaccharide sequence, the shortest chain required for antithrombin inhibition of activated factor X without antithrombin action. Fondaparinux has no effect on coagulation tests and does not bind to platelet factor 4 or promote heparin-induced thrombocytopenia. Fondaparinux inhibits thrombin generation and the growth of thrombi in in vitro and in vivo models. Phase I trials have shown a 100% bioavailability after subcutaneous (s.c.) administration, a rapid onset of action and an approximate half-life of 13.5 h. Fondaparinux is cleared as an active substance by the kidneys. In elderly patients, renal clearance is reduced and the half-life is longer. The phase II Pentathlon trial demonstrated significant dose-dependent reductions in the frequency of venous thromboembolism in total hip-replacement patients and the optimal dose was determined to be 2.5 mg s.c./24 h. Four phase III trials have evaluated fondaparinux starting 6 hours after surgery compared with enoxaparin for prevention of venous thromboembolism following orthopedic surgery in 7,344 patients. The risk of thrombosis was reduced by 50% with fondaparinux and no differences were observed in death or severe bleeding. In a phase II trial, similar efficacy and incidence of major bleeding were seen with fondaparinux s.c. compared with dalteparin s.c. in the treatment of deep venous thrombosis. In patients with acute myocardial infarction, the efficacy of fondaparinux during fibrinolytic therapy was assessed in 326 patients who had acute coronary syndromes of less than a 6 hour duration, showing a slight but statistically not significant advantage for fondaparinux over unfractionated heparin in the coronary angiographies. There is currently no antidote for fondaparinux.

  2. Sodium thioglycollate enhances pollen germeination and pollen tube elongation in cruciferous species

    EPA Science Inventory

    Sodium thioglycollate is a reducing agent used in microbiological growth media to enhance the growth of anerobic, microaerophilic, and facultative organisms, and in eukaryotic tissue extraction buffers to inhibit damaging oxidative reactions. Sodium thioglycollate was added to a ...

  3. Astrocyte Sodium Signalling and Panglial Spread of Sodium Signals in Brain White Matter.

    PubMed

    Moshrefi-Ravasdjani, Behrouz; Hammel, Evelyn L; Kafitz, Karl W; Rose, Christine R

    2017-02-18

    In brain grey matter, excitatory synaptic transmission activates glutamate uptake into astrocytes, inducing sodium signals which propagate into neighboring astrocytes through gap junctions. These sodium signals have been suggested to serve an important role in neuro-metabolic coupling. So far, it is unknown if astrocytes in white matter-that is in brain regions devoid of synapses-are also able to undergo such intra- and intercellular sodium signalling. In the present study, we have addressed this question by performing quantitative sodium imaging in acute tissue slices of mouse corpus callosum. Focal application of glutamate induced sodium transients in SR101-positive astrocytes. These were largely unaltered in the presence of ionotropic glutamate receptors blockers, but strongly dampened upon pharmacological inhibition of glutamate uptake. Sodium signals induced in individual astrocytes readily spread into neighboring SR101-positive cells with peak amplitudes decaying monoexponentially with distance from the stimulated cell. In addition, spread of sodium was largely unaltered during pharmacological inhibition of purinergic and glutamate receptors, indicating gap junction-mediated, passive diffusion of sodium between astrocytes. Using cell-type-specific, transgenic reporter mice, we found that sodium signals also propagated, albeit less effectively, from astrocytes to neighboring oligodendrocytes and NG2 cells. Again, panglial spread was unaltered with purinergic and glutamate receptors blocked. Taken together, our results demonstrate that activation of sodium-dependent glutamate transporters induces sodium signals in white matter astrocytes, which spread within the astrocyte syncytium. In addition, we found a panglial passage of sodium signals from astrocytes to NG2 cells and oligodendrocytes, indicating functional coupling between these macroglial cells in white matter.

  4. Doped with Sodium Acetate and Metallic Sodium

    NASA Astrophysics Data System (ADS)

    Tada, Satoki; Isoda, Yukihiro; Udono, Haruhiko; Fujiu, Hirofumi; Kumagai, Shunji; Shinohara, Yoshikazu

    2014-06-01

    We have investigated the thermoelectric properties of p-type Na-doped Mg2 Si0.25Sn0.75 solid solutions prepared by liquid-solid reaction and hot-pressing methods. Na was introduced into Mg2Si0.25Sn0.75 by using either sodium acetate (CH3COONa) or metallic sodium (2 N). The samples doped with sodium acetate consisted of phases with antifluorite structure and a small amount of MgO as revealed by x-ray diffraction, whereas the sample doped with metallic sodium contained the Sn, MgO, and Mg2SiSn phases. The hole concentrations of Mg1.975Na0.025Si0.25Sn0.75 doped by sodium acetate and metallic sodium were 1.84 × 1025 m-3 and 1.22 × 1025 m-3, respectively, resulting in resistivities of 4.96 × 10-5 Ω m (sodium acetate) and 1.09 × 10-5 Ω m (metallic sodium). The Seebeck coefficients were 198 μV K-1 (sodium acetate) and 241 μV K-1 (metallic sodium). The figures of merit for Mg1.975Na0.025Si0.25Sn0.75 were 0.40 × 10-3 K-1 (sodium acetate) and 0.25 × 10-3 K-1 (metallic sodium) at 400 K. Thus, sodium acetate is a suitable Na dopant for Mg2Si1- x Sn x .

  5. Tracking Sodium-Antimonide Phase Transformations in Sodium-Ion Anodes: Insights from Operando Pair Distribution Function Analysis and Solid-State NMR Spectroscopy

    PubMed Central

    2016-01-01

    Operando pair distribution function (PDF) analysis and ex situ 23Na magic-angle spinning solid-state nuclear magnetic resonance (MAS ssNMR) spectroscopy are used to gain insight into the alloying mechanism of high-capacity antimony anodes for sodium-ion batteries. Subtraction of the PDF of crystalline NaxSb phases from the total PDF, an approach constrained by chemical phase information gained from 23Na ssNMR in reference to relevant model compounds, identifies two previously uncharacterized intermediate species formed electrochemically; a-Na3–xSb (x ≈ 0.4–0.5), a structure locally similar to crystalline Na3Sb (c-Na3Sb) but with significant numbers of sodium vacancies and a limited correlation length, and a-Na1.7Sb, a highly amorphous structure featuring some Sb–Sb bonding. The first sodiation breaks down the crystalline antimony to form first a-Na3–xSb and, finally, crystalline Na3Sb. Desodiation results in the formation of an electrode formed of a composite of crystalline and amorphous antimony networks. We link the different reactivity of these networks to a series of sequential sodiation reactions manifesting as a cascade of processes observed in the electrochemical profile of subsequent cycles. The amorphous network reacts at higher voltages reforming a-Na1.7Sb, then a-Na3–xSb, whereas lower potentials are required for the sodiation of crystalline antimony, which reacts to form a-Na3–xSb without the formation of a-Na1.7Sb. a-Na3–xSb is converted to crystalline Na3Sb at the end of the second discharge. We find no evidence of formation of NaSb. Variable temperature 23Na NMR experiments reveal significant sodium mobility within c-Na3Sb; this is a possible contributing factor to the excellent rate performance of Sb anodes. PMID:26824406

  6. Selective speciation of inorganic antimony on tetraethylenepentamine bonded silica gel column and its determination by graphite furnace atomic absorption spectrometry.

    PubMed

    Mendil, Durali; Bardak, Hilmi; Tuzen, Mustafa; Soylak, Mustafa

    2013-03-30

    A speciation system for antimony (III) and antimony (V) ions that based on solid phase extraction on tetraethylenepentamine bonded silica gel has been established. Antimony was determined by graphite furnace atomic absorption spectrometry (GF-AAS). Analytical conditions including pH, sample volume, etc., were studied for the quantitative recoveries of Sb (III) and Sb (V). Matrix effects on the recovery were also investigated. The recovery values and detection limit for antimony (III) at optimal conditions were found as >95% and 0.020 μg L(-1), respectively. Preconcentration factor was calculated as 50. The capacity of adsorption for the tetraethylenepentamine bonded silica gel was 7.9 mg g(-1). The validation was checked by analysis of NIST SRM 1573a Tomato laves and GBW 07605 Tea certified reference materials. The procedure was successfully applied to speciation of antimony in tap water, mineral water and spring water samples. Total antimony was determined in refined salt, unrefined salt, black tea, rice, tuna fish and soil samples after microwave digestion and presented enrichment method combination.

  7. Fast sequential determination of antimony and lead in pewter alloys using high-resolution continuum source flame atomic absorption spectrometry.

    PubMed

    Dessuy, Morgana B; de Jesus, Robson M; Brandao, Geovani C; Ferreira, Sergio L C; Vale, Maria Goreti R; Welz, Bernhard

    2013-01-01

    A simple method has been developed to determine antimony and lead in pewter alloy cups produced in Brazil, using fast sequential determination by high-resolution continuum source flame atomic absorption spectrometry. The samples were dissolved in HCl and H(2)O(2), employing a cold finger system in order to avoid analyte losses. The main resonance line of lead at 217.001 nm and a secondary line of antimony at 212.739 nm were used. The limits of detection for lead and antimony were 0.02 and 5.7 mg L(-1), respectively. The trueness of the method was established by recovery tests and comparing the results obtained by the proposed method with those obtained by inductively coupled plasma optical emission spectrometry. The results were compared using a student's t-test and there was no significant difference at a 95% confidence interval. With the developed methods, it was possible to determine accurately antimony and lead in pewter samples. The lead concentration found in the analysed samples was around 1 mg g(-1), which means that they are not lead free; however, the content was below the maximum allowed level of 5 mg g(-1). The antimony content, which was found to be between 40 and 46 mg g(-1), is actually of greater concern, as antimony is known to be potentially toxic already at very low concentrations, although there is no legislation yet for this element.

  8. Lithium diffusivity in antimony-based intermetallic and FeSb-TiC composite anodes as measured by GITT.

    PubMed

    Allcorn, Eric; Kim, Sang Ok; Manthiram, Arumugam

    2015-11-21

    The diffusion coefficient of lithium is an important parameter in determining the rate capability of an electrode and its ability to deliver high power output. Galvanostatic intermittent titration technique (GITT) is a quick electrochemical method to determine diffusion coefficients in electrode materials and is applied here to antimony-based anodes for lithium-ion batteries. Like other alloy anodes, antimony suffers from large volume change and a short cycle life, so GITT is also applied to determine the effects on lithium diffusivity of antimony intermetallics and composite electrodes designed to mitigate these issues. Pure antimony is measured to have a diffusion coefficient of 4.0 × 10(-9) cm(2) s(-1), in agreement with previously measured values. The intermetallics NiSb, FeSb, and FeSb2 all demonstrate diffusivity values within an order of magnitude of antimony, while Cu2Sb shows roughly an order of magnitude improvement due to the persistence of the Cu2Sb phase during cycling. The composite electrode FeSb-TiC is shown to offer significant enhancement of the diffusion coefficient positively correlated with higher concentrations of TiC in the composite up to a maximum value of 1.9 × 10(-7) cm(2) s(-1) at 60 wt% TiC, nearly two full orders of magnitude greater than that of pure antimony.

  9. Overexpression of ubiquitin and amino acid permease genes in association with antimony resistance in Leishmania tropica field isolates.

    PubMed

    Kazemi-Rad, Elham; Mohebali, Mehdi; Khadem-Erfan, Mohammad Bagher; Hajjaran, Homa; Hadighi, Ramtin; Khamesipour, Ali; Rezaie, Sassan; Saffari, Mojtaba; Raoofian, Reza; Heidari, Mansour

    2013-08-01

    The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime®) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in a resistant isolate compared to a sensitive one. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance.

  10. [Antimicrobial activity exerted by sodium dichloroisocyanurate].

    PubMed

    D'Auria, F D; Simonetti, G; Strippoli, V

    1989-01-01

    for its activity. It is interesting to note that well known bacteria, that are resistant to the common antimicrobial agents, such as Pseudomonas aeruginosa, were inhibited by sodium dichloroisocyanurate in a rapid bactericidal action. Our data demonstrates that no significant adverse influence on the activity of sodium dichloroisocyanurate was shown by pH and by temperature even if in some experimental conditions increased activity was noticed at pH = 6.6. The sodium dichloroisocyanurate has demonstrated good activity against Trichomonas vaginalis. This fact extends the broad-spectrum activity of sodium dichloroisocyanurate to the protozoa. In conclusion, sodium dichloroisocyanurate has demonstrated a good activity against all tested strains, furthermore its activity did not decrease in the presence of 1% of organic substance (serum etc.).(ABSTRACT TRUNCATED AT 400 WORDS)

  11. Effect of sodium salt on anaerobic digestion of kitchen waste.

    PubMed

    Anwar, Naveed; Wang, Wen; Zhang, Jie; Li, Yeqing; Chen, Chang; Liu, Guangqing; Zhang, Ruihong

    2016-01-01

    The effect of different sodium salt concentration on anaerobic digestion of kitchen waste was investigated. The methane production performance, the corresponding methane production model and sodium salt inhibition model were studied, and the degradation efficiency was analyzed. With the increase of sodium salt concentration, the methane yield and the maximal methane production rate decreased along with the increase of lag phase time. The highest methane yield of 594 mL/g-VSadded (VS: volatile solids) was found with no sodium salt addition while the lowest was obtained with addition of 16 g/L NaCl. The declines of the methane yield were negligible when the sodium salt concentration was below 8 g/L, which corresponded to <10% inhibiting efficiency. In contrast, a sharp decrease of methane yield was observed with addition of >8 g/L NaCl (causing 17-80% inhibition). Five kinds of regression models were developed to describe the sodium salt inhibition efficiency, and the cubic regression model of y = 0.508 + 2.401x - 0.369x(2) + 0.033x(3) showed the best fitting. The volatile fatty acids/ethanol gradually accumulated along with the increase of the sodium salt concentration, and the volatile solid removal efficiency represented a gradual decline accordingly. It is recommended that the sodium salt concentration in the anaerobic digesters should be controlled below 8 g/L in order to avoid intense methane inhibition.

  12. Block of sodium channels by internal mono- and divalent guanidinium analogues. Modulation by sodium ion concentration.

    PubMed Central

    Danko, M; Smith-Maxwell, C; McKinney, L; Begenisich, T

    1986-01-01

    We have investigated the block of squid axon sodium channels by mono- and divalent guanidinium analogues. The action of these compounds on steady state sodium currents was independent of the presence or absence of the normal inactivation process. Block by both mono- and divalent analogues was voltage-dependent, but was a steeper function of potential for divalent molecules. The voltage-dependence could not, in general, be reproduced by a simple model based on Boltzmann's equation. Inhibition of steady state currents by guanidinium ions with 50 mM internal sodium was reasonably well described by a 1:1 drug/channel binding function. Increasing the internal sodium ion concentration increased both the degree and voltage-dependence of current inhibition. This is in sharp contrast to the decrease in inactivation caused by internal sodium. Changes in the external sodium concentration had very little effect on drug block. These results are consistent with a model of the sodium channel as a multi-ion pore. Only a small increase in block can be produced by increased internal sodium in a three-barrier two-site model, but a four-barrier three-site model can reproduce these experimental findings. The implications of these results for physical models of inactivation are discussed. PMID:2420382

  13. A Species-Specific Approach to the Use of Non-Antimony Treatments for Cutaneous Leishmaniasis

    PubMed Central

    Ramanathan, Roshan; Talaat, Kawsar R.; Fedorko, Daniel P.; Mahanty, Siddhartha; Nash, Theodore E.

    2011-01-01

    We used a species-specific approach to treat 10 patients with cutaneous leishmaniasis diagnosed using polymerase chain reaction. Non-antimony treatments (oral miltefosine, ketoconazole, and liposomal amphotericin B) were chosen as an alternative to pentavalent antimony drugs based on likely or proven drug efficacy against the infecting species. Leishmania Viannia panamensis was diagnosed in three patients and treated successfully with oral ketoconazole. Miltefosine treatment cured two patients with L. infantum chagasi. A wide variety of Leishmania responded to liposomal amphotericin B administered for 5–7 days. Three patients with L. V. braziliensis, one patient with L. tropica, and two patients with L. infantum chagasi were treated successfully. One person with L. V. braziliensis healed slowly because of a resistant bacterial superinfection, and a second patient with L. infantum chagasi relapsed and was retreated with miltefosine. These drugs were reasonably well-tolerated. In this limited case series, alternative non-antimony–based regimens were convenient, safe, and effective. PMID:21212212

  14. Thermal stability and spectroscopic properties of Er 3+-doped antimony-borosilicate glasses

    NASA Astrophysics Data System (ADS)

    Qian, Q.; Zhao, C.; Yang, G. F.; Yang, Z. M.; Zhang, Q. Y.; Jiang, Z. H.

    2008-11-01

    This paper reports on the optical spectroscopic properties and thermal stability of Er 3+-doped antimony-borosilicate glasses for developing 1.5 μm optical amplifiers. Upon excitation at 980 nm laser diode, an intense 1.5 μm infrared fluorescence has been observed with the maximum full width at half maximum (FWHM) of 90 nm for Er 3+-doped antimony-borosilicate glasses. The emission cross-section and the lifetime of the 4I13/2 level of Er 3+ ions are 6.3 × 10 -21 cm 2 and 0.30 ms, respectively. It is noted that the product of the emission cross-section and FWHM of the glass studied is as great as 567 × 10 -21 cm 2 nm, which is comparable or higher than that of bismuthate and tellurite glasses.

  15. Antimony segregation in stressed SiGe heterostructures grown by molecular beam epitaxy

    SciTech Connect

    Drozdov, M. N.; Novikov, A. V.; Yurasov, D. V.

    2013-11-15

    The effects of the growth temperature, composition, and elastic strains in separate layers on the segregation of antimony are studied experimentally for stressed SiGe structures grown by molecular beam epitaxy. It is established that the growth conditions and parameters of the structures exert an interrelated influence on the segregation of Sb: the degree of the influence of the composition and elastic stresses in the SiGe layers on Sb segregation depends on the growth temperature. It is shown that usage of a method previously proposed by us for the selective doping of silicon structures with consideration for the obtained dependences of Sb segregation on the growth conditions and parameters of the SiGe layers makes it possible to form SiGe structures selectively doped with antimony.

  16. Sandwich heterostructures of antimony trioxide and bismuth trioxide films: Structural, morphological and optical analysis

    NASA Astrophysics Data System (ADS)

    Condurache-Bota, Simona; Praisler, Mirela; Gavrila, Raluca; Tigau, Nicolae

    2017-01-01

    Thin film heterostructures can be advantageous since they either exhibit novel or a combination of the properties of their components. Here we propose sandwich-type of heterostructures made of antimony trioxide and bismuth trioxide thin films, which were deposited on glass substrates by thermal vacuum deposition at three substrate temperatures, 50° Celsius apart. Their morphology and optical properties are studied as compared to the corresponding monolayers. It was found that even small substrate temperature changes strongly influence their morphology, increasing their roughness, while the optical transmittance shows a slight decrease as compared with the individual layers. The corresponding absorption coefficient exhibits intermediate values as compared to the component oxides, while the energy bandgaps for the indirect allowed transitions move towards the Infrared when overlapping the antimony and bismuth trioxides.

  17. Numerical simulation and experimental characterization of the performance evolution of a liquid antimony anode fuel cell

    NASA Astrophysics Data System (ADS)

    Cao, Tianyu; Shi, Yixiang; Wang, Hongjian; Cai, Ningsheng

    2015-06-01

    A solid oxide fuel cell (SOFC) with a liquid antimony anode is fabricated based on a smooth single crystal YSZ electrolyte substrate and a porous Pt cathode. The performance of the liquid antimony anode was tested under "battery mode", with the anode chamber shielded in argon throughout the test and the cathode exposed to air. Polarization curves were taken and a long term constant potential discharging test was carried out afterwards. Taking electrochemical reaction, mass transport and microstructure of the liquid Sb anode into consideration, a one dimensional mathematical model was built and then validated by the polarization curve and the constant potential discharging performance curve obtained during the test. This model analyzes the metallic Sb distribution in the anode during cell operation, explains the cell performance evolution base on the microstructural development of the liquid Sb anode and simulates how the anode microstructure affects the cell performance.

  18. An additive approach to low temperature zero pressure sintering of bismuth antimony telluride thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Catlin, Glenn C.; Tripathi, Rajesh; Nunes, Geoffrey; Lynch, Philip B.; Jones, Howard D.; Schmitt, Devin C.

    2017-03-01

    This paper presents an additive-based approach to the formulation of thermoelectric materials suitable for screen printing. Such printing processes are a likely route to such thermoelectric applications as micro-generators for wireless sensor networks and medical devices, but require the development of materials that can be sintered at ambient pressure and low temperatures. Using a rapid screening process, we identify the eutectic combination of antimony and tellurium as an additive for bismuth-antimony-telluride that enables good thermoelectric performance without a high pressure step. An optimized composite of 15 weight percent Sb7.5Te92.5 in Bi0.5Sb1.5Te3 is scaled up and formulated into a screen-printable paste. Samples fabricated from this paste achieve a thermoelectric figure of merit (ZT) of 0.74 using a maximum processing temperature of 748 K and a total thermal processing budget of 12 K-hours.

  19. Effect of iron plaque on antimony uptake by rice (Oryza sativa L.).

    PubMed

    Cui, Xiao-Dan; Wang, Yu-Jun; Hockmann, Kerstin; Zhou, Dong-Mei

    2015-09-01

    Although iron (Fe) plaque has been shown to significantly affect the uptake of toxic antimony (Sb) by rice, knowledge about the influence of iron plaque on antimony (Sb) (amount, mechanisms, etc) is, however, limited. Here, the effect of Fe plaque on Sb(III) and Sb(V) (nominal oxidation states) uptake by rice (Oryza sativa L.) was investigated using hydroponic experiments and synchrotron-based techniques. The results showed that iron plaque immobilized Sb on the surface of rice roots. Although the binding capacity of iron plaque for Sb(III) was markedly greater than that for Sb(V), significantly more Sb(III) was taken up by roots and transported to shoots. In the presence of Fe plaque, Sb uptake into rice roots was significantly reduced, especially for Sb(III). However, this did not translate into decreasing Sb concentrations in rice shoots and even increased shoot Sb concentrations during high Fe-Sb(III) treatment.

  20. Reaction of Antimony-Uranium Composite Oxide in the Chlorination Treatment of Waste Catalyst - 13521

    SciTech Connect

    Sawada, Kayo; Hirabayashi, Daisuke; Enokida, Youichi

    2013-07-01

    The effect of oxygen gas concentration on the chlorination treatment of antimony-uranium composite oxide catalyst waste was investigated by adding different concentrations of oxygen at 0-6 vol% to its chlorination agent of 0.6 or 6 vol% hydrogen chloride gas at 1173 K. The addition of oxygen tended to prevent the chlorination of antimony in the oxide. When 6 vol% hydrogen chloride gas was used, the addition of oxygen up to 0.1 vol% could convert the uranium contained in the catalyst to U{sub 3}O{sub 8} without any significant decrease in the reaction rate compared to that of the treatment without oxygen. (authors)

  1. Synthesis of Antimony Nanotubes via Facile Template-Free Solvothermal Reactions.

    PubMed

    Li, Ruxue; Wang, Xiaohua; Wang, Xinwei; Zhang, Haoran; Pan, Jingxin; Tang, Jilong; Fang, Dan; Ma, Xiaohui; Li, Yongfeng; Yao, Bin; Fan, Jie; Wei, Zhipeng

    2016-12-01

    Uniform antimony (Sb) nanotubes were successfully synthesized via a facile solvothermal method without the need for any surfactants or templates. The Sb nanotubes are confirmed to be pure rhombohedral phase and have better crystallinity. These nanotubes show middle-hollow and open-ended structures, as well as multi-walled structures with the wall thickness of about 10 nm. Also, they have an average size of the diameter of about 50 nm and the length of about 350 nm. On the basis of the structural and morphological studies, a possible rolling mechanism is proposed to explain the formation of Sb nanotubes. It is expected that uniform Sb nanotubes can further be used in wide applications. Graphical Abstract A possible rolling-formation mechanism is proposed for forming pure rhombhedral phase and high crystallinity antimony nanotubes without any surfactants or templates via a facile solvothermal method.

  2. Synthesis, spectroscopic characterization and antibacterial activity of antimony(III) bis(dialkyldithiocarbamato)alkyldithiocarbonates

    NASA Astrophysics Data System (ADS)

    Chauhan, H. P. S.; Bakshi, Abhilasha; Bhatiya, Sumit

    2011-10-01

    Some mixed sulfur donor ligand complexes of antimony(III) of the general formula [(R 2NCS 2)] 2SbS 2COR' where R = CH 3, C 2H 5 and R' = Me, Et, Pr n, Pr i, Bu n and Bu i have been synthesized by the reaction of antimony(III) bis(dialkyldithiocarbamate) chloride with potassium organodithiocarbonate in an equimolar ratio by stirring at room temperature in benzene/CS 2 mixture. These complexes have been characterized by physicochemical [elemental analysis, melting points and molecular weight determinations] and spectral [UV, IR, Far-IR, NMR ( 1H and 13C), FAB + mass and powder X-ray diffraction] studies. Free ligands and synthesized complexes have also been screened against different bacterial strains and results obtained made it desirable to delineate a comparison between free ligands, standard drug used and synthesized complexes.

  3. Evaluation of Antimony Thioantimonate in Three in Vitro Short-Term Assays.

    DTIC Science & Technology

    1984-12-14

    dimethylsulfoxide [Cl potassium chloride DM dimethylnitrosamine MCA 3-me thylcholanthrene CA chromosome aberrations Sb(SbS 4 antimony thioantimonate TG...control compounds, ethylmethanesulfonate (EMS) lot #AZG and dImethylnitrosamIne were purchased from Eastman Kodak Company and Sigma Chemical Company...ethylmethanesulfonate (EMS) at 248 Lg/ml in the - absence of S9 or dimethylnitrosamine (DMN) at 100 jig/ml in the presence of S9. The cells were treated

  4. The heat capacity of solid antimony telluride Sb2Te3

    NASA Astrophysics Data System (ADS)

    Pashinkin, A. S.; Malkova, A. S.; Mikhailova, M. S.

    2008-05-01

    The literature data on the heat capacity of solid antimony telluride over the range 53 895 K were analyzed. The heat capacity of Sb2Te3 was measured over the range 350 700 K on a DSM-2M calorimeter. The equation for the temperature dependence was suggested. The thermodynamic functions of Sb2Te3 were calculated over the range 298.15 700 K.

  5. Development and characterization of ion selective electrode for the assay of antimony.

    PubMed

    Mostafa, G A E

    2007-03-15

    The construction and general performance characteristics of two novel potentiometric carbon paste electrodes (CPE) responsive to antimony are described. These sensors are based on the use of the ion associate complexes of tetraiodoantimonate (TIA) anion with cetylpyridinium (CP) and triphenyl tetrazolium (TPT) counter cations as ion exchange site in a carbon paste matrix. The two sensors exhibits fast, stable and near-Nernstian for the mono charged TIA anion over the concentration range 1x10(-3) to 10(-6)M at 25 degrees C in the pH range 4-10 with anionic slope of 58.0+/-0.5 and 55.0+/-0.7 per concentration decade for TIA-CP and TIA-TPT, respectively. The lower detection limits are 4 and 5x10(-6)M and response time are 20 and 30s in the same order of both electrodes. Selectivity coefficients for antimony relative to a number of different cations and anions were investigated. There is negligible interference from many inorganic cation and anion except for Hg(2+), Cd(2+), and Bi(3+); however, their effect were eliminated by EDTA. The determination of 1.0-120.0mug/ml of antimony in aqueous solutions shows an average recovery of 99.0 and 97.5% with relative standard deviation of 2.0% for both electrodes at 40mug/ml. The determination of antimony in wastewater and some antibilharzial compounds using the proposed electrodes gave results that compare favorably with those obtained by the atomic absorption spectrometric method. Precipitation titrations involving cetylpyridinium chloride as titrant are monitored with both electrodes with inflection point of 180 and 100mV for TIA-CP and TIA-TPT, respectively.

  6. Bi-antimony capped Keggin polyoxometalate modified with Cu-ligand fragment

    SciTech Connect

    Huang, Jiao; Han, Zhangang; Zhang, Heng; Yu, Haitao; Zhai, Xueliang

    2012-10-15

    Three polyoxometalates consisting of bi-antimony capped Keggin-type clusters: [Cu(mbpy){sub 2}]{sub 2}[PMo{sub 12}O{sub 40}Sb{sub 2}]{center_dot}4H{sub 2}O (1), [Cu(mbpy){sub 2}][PMo{sub 12}O{sub 40}Sb{sub 2}] (2) and {l_brace}Cu(mbpy)[Cu(mbpy){sub 2}]{sub 2}{r_brace}[VMo{sub 8}V{sub 4}O{sub 40}Sb{sub 2}]{center_dot}2H{sub 2}O (3) (mbpy=4,4 Prime -dimethyl-2,2 Prime - dipyridyl in 1 and 2; 5,5 Prime -dimethyl-2,2 Prime -dipyridyl in 3) have been synthesized and characterized by IR, X-ray powder diffraction, TG analysis and electrochemical property. Single-crystal analysis revealed that all of three compounds are built upon bi-antimony capped Keggin-type polyoxoanions and Cu-mbpy cations. In 1-3, two Sb{sup III} centers located at the two opposite of anionic surface adopt fundamentally tetragonal pyramidal coordination geometry. Both compounds 1 and 2 consist of P-centered Keggin structure, while compound 3 presents a V-centered Keggin anion. The Keggin-type anions present different structural features: isolated cluster in 1 and Cu-ligand-supported cluster in 2 and 3. - Graphical abstract: Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters modified with Cu-ligand cations have been synthesized and characterized. Highlights: Black-Right-Pointing-Pointer Three hybrid compounds consisting of bi-antimony capped Keggin-type clusters have been synthesized. Black-Right-Pointing-Pointer Two Sb{sup III} centers located at the two opposite of anionic surface adopt tetragonal pyramidal coordination geometry. Black-Right-Pointing-Pointer The anions present different structural features: isolated and Cu-ligand-supported cluster.

  7. Chemically deposited thin films of sulfides and selenides of antimony and bismuth as solar energy materials

    NASA Astrophysics Data System (ADS)

    Nair, M. T.; Nair, Padmanabhan K.; Garcia, V. M.; Pena, Y.; Arenas, O. L.; Garcia, J. C.; Gomez-Daza, O.

    1997-10-01

    Chemical bath deposition techniques for bismuth sulfide, bismuth selenide, antimony sulfide, and antimony selenide thin films of about 0.20 - 0.25 micrometer thickness are reported. All these materials may be considered as solar absorber films: strong optical absorption edges, with absorption coefficient, (alpha) , greater than 104 cm-1, are located at 1.31 eV for Bi2Se3, 1.33 eV for Bi2S3, 1.8 eV for Sb2S3, and 1.35 eV for Sb2Se3. As deposited, all the films are nearly amorphous. However, well defined crystalline peaks matching bismuthinite (JCPDS 17- 0320), paraguanajuatite (JCPDS 33-0214), and stibnite (JCPDS 6-0474) and antimony selenide (JCPDS 15-0861) for Bi2S3, Bi2Se3, Sb2S3 and Sb2Se3 respectively, are observed when the films are annealed in nitrogen at 300 degrees Celsius. This is accompanied by a substantial modification of the electrical conductivity in the films: from 10-7 (Omega) -1 cm-1 (in as prepared films) to 10 (Omega) -1 cm-1 in the case of bismuth sulfide and selenide films, and enhancement of photosensitivity in the case of antimony sulfide films. The chemical deposition of a CuS/CuxSe film on these Vx- VIy films and subsequent annealing at 300 degrees Celsius for 1 h at 1 torr of nitrogen leads to the formation of p-type films (conductivity of 1 - 100 (Omega) -1 cm-1) of multinary composition. Among these, the formation of Cu3BiS3 (JCPDS 9-0488) and Cu3SbS4 (JCPDS 35- 0581), CuSbS2 (JCPDS 35-0413) have been clearly detected. Solar energy applications of these films are suggested.

  8. Long term improvement in the treatment of canine leishmaniosis using an antimony liposomal formulation.

    PubMed

    Valladares, J E; Riera, C; González-Ensenyat, P; Díez-Cascón, A; Ramos, G; Solano-Gallego, L; Gállego, M; Portús, M; Arboix, M; Alberola, J

    2001-05-09

    Pharmacokinetic and clinical effectiveness of liposome-encapsulated N-methylglucamine antimoniate (LMA) was performed in dogs suffering from experimental leishmaniosis. LMA was compared with N-methylglucamine antimoniate (MGA), the same drug in its free form. Sb plasma concentrations for LMA were always higher than those for MGA. Mean residence time (MRT), half-life time (t(1/2)) and clearance (Cl) showed that Sb was eliminated slower after liposome administration. The high volume of distribution (Vd) obtained with LMA suggests that Sb could achieve therapeutic concentrations in parasite-infected tissues. Average plasma concentration at steady state (Css(ave)) shows that Sb body concentrations after LMA treatment (9.8 mg/kg Sb, each 24h) would be effective in Leishmania infantum canine infection. Comparing LMA with MGA in a 1-year follow-up we observed no relapses for LMA and total protein and gammaglobulin concentrations were within normal range, while for MGA both began to rise 3 months after treatment. Use of antimonial liposomal formulations may restore effectiveness to an existing drug and reduce toxicity.

  9. Separation of Arsenic from the Antimony-Bearing Dust through Selective Oxidation Using CuO

    NASA Astrophysics Data System (ADS)

    Zhong, Da-Peng; Li, Lei; Tan, Cheng

    2017-04-01

    A pyrometallurgical process of selective oxidation roasting of the antimony-bearing dust using CuO is put forward, in which the antimony component is oxidized to Sb2O4 staying in the roasted residue, and arsenic is volatilized in the form of As2O3. The addition of CuO has an active effect on the arsenic volatilization, because structures of some complicated As-Sb phases in the dust are destroyed after the "Sb" component in them is oxidized to Sb2O4, and this part of arsenic might be transformed to As2O3, which continues to volatilize. However, the arsenic volatilization rate decreases with the CuO amount in a certain range, which is attributed to the greater formation of Cu3 (AsO4)2 and Cu3As. Under the conditions of roasting temperature of 673 K (400 °C), roasting time of 100 minutes, CuO amount of 34.54 mass pct, and N2 flow rate of 30 mL/min, 91.50 pct arsenic and only 8.63 pct antimony go into the smoke.

  10. Separation of Arsenic from the Antimony-Bearing Dust through Selective Oxidation Using CuO

    NASA Astrophysics Data System (ADS)

    Zhong, Da-Peng; Li, Lei; Tan, Cheng

    2017-01-01

    A pyrometallurgical process of selective oxidation roasting of the antimony-bearing dust using CuO is put forward, in which the antimony component is oxidized to Sb2O4 staying in the roasted residue, and arsenic is volatilized in the form of As2O3. The addition of CuO has an active effect on the arsenic volatilization, because structures of some complicated As-Sb phases in the dust are destroyed after the "Sb" component in them is oxidized to Sb2O4, and this part of arsenic might be transformed to As2O3, which continues to volatilize. However, the arsenic volatilization rate decreases with the CuO amount in a certain range, which is attributed to the greater formation of Cu3 (AsO4)2 and Cu3As. Under the conditions of roasting temperature of 673 K (400 °C), roasting time of 100 minutes, CuO amount of 34.54 mass pct, and N2 flow rate of 30 mL/min, 91.50 pct arsenic and only 8.63 pct antimony go into the smoke.

  11. Study on Determination of Antimony in Environmental Samples by Neutron Activation Analysis

    NASA Astrophysics Data System (ADS)

    Martins, Tassiane Cristina Gomes; Saiki, Mitiko; Zahn, Guilherme Soares

    2011-08-01

    There is an increasing interest in the determination of antimony in environmental samples since this element is cumulative and potentially toxic at very low concentrations. Moreover, the quantification of antimony presents difficulties due to its low concentrations in the samples and to the interference problem in the analyses. In this study, neutron activation analysis procedure was established in order to obtain reliable results for Sb determination in environmental samples. For this study ten reference materials were analyzed. Aliquots of these materials and synthetic standard of Sb were irradiated at the IEA- R1 nuclear reactor under a thermal neutron flux of about 5×1012 n cm-2 s-1 for 8 or 16 hours. The induced gamma activities of 122Sb and 124Sb were measured using a hyperpure Ge detector. Antimony concentrations were calculated by comparative method and the uncertainties of the results were estimated using statistical counting errors of the sample and standard. Relative errors calculated demonstrated that the accuracy of the results depends on the Sb radioisotope measured and the decay time for counting.

  12. Altering the dewetting characteristics of ultrathin gold and silver films using a sacrificial antimony layer.

    PubMed

    Farzinpour, P; Sundar, A; Gilroy, K D; Eskin, Z E; Hughes, R A; Neretina, S

    2012-12-14

    Solid state dewetting of ultrathin films is the most straightforward means of fabricating substrate-supported noble metal nanostructures. This assembly process is, however, quite inflexible, yielding either densely packed smaller structures or widely spaced larger structures. Here, we demonstrate the utility of introducing a sacrificial antimony layer between the substrate and noble metal overlayer. We observe an agglomeration process which is radically altered by the concurrent sublimation of antimony. In stark contrast with conventional dewetting, where the thickness of the deposited metal film determines the characteristic length scales of the assembly process, it is the thickness of the sacrificial antimony layer which dictates both the nanoparticle size and interparticle spacing. The result is a far more flexible self-assembly process where the nanoparticle size and areal density can be varied widely. Demonstrations show nanoparticle areal densities which are varied over four orders of magnitude assembled from the identical gold layer thickness, where the accompanying changes to nanostructure size see a systematic shift in the wavelength of the localized surface plasmon resonance. As a pliable self-assembly process, it offers the opportunity to tailor the properties of an ensemble of nanostructures to meet the needs of specific applications.

  13. Antimony retention and release from drained and waterlogged shooting range soil under field conditions.

    PubMed

    Hockmann, Kerstin; Tandy, Susan; Lenz, Markus; Reiser, René; Conesa, Héctor M; Keller, Martin; Studer, Björn; Schulin, Rainer

    2015-09-01

    Many soils polluted by antimony (Sb) are subject to fluctuating waterlogging conditions; yet, little is known about how these affect the mobility of this toxic element under field conditions. Here, we compared Sb leaching from a calcareous shooting range soil under drained and waterlogged conditions using four large outdoor lysimeters. After monitoring the leachate samples taken at bi-weekly intervals for >1.5 years under drained conditions, two of the lysimeters were subjected to waterlogging with a water table fluctuating according to natural rainfall water infiltration. Antimony leachate concentrations under drained conditions showed a strong seasonal fluctuation between 110 μg L(-1) in summer and <40 μg L(-1) in winter, which closely correlated with fluctuations in dissolved organic carbon (DOC) concentrations. With the development of anaerobic conditions upon waterlogging, Sb in leachate decreased to 2-5 μg L(-1) Sb and remained stable at this level. Antimony speciation measurements in soil solution indicated that this decrease in Sb(V) concentrations was attributable to the reduction of Sb(V) to Sb(III) and the stronger sorption affinity of the latter to iron (Fe) (hydr)oxide phases. Our results demonstrate the importance of considering seasonal and waterlogging effects in the assessment of the risks from Sb-contaminated sites.

  14. Accumulation of antimony and other potentially toxic elements in plants around a former antimony mine located in the Ribes Valley (Eastern Pyrenees)

    NASA Astrophysics Data System (ADS)

    Bech, Jaume; Corrales, Isabel; Duran, Paola; Roca, Núria; Tume, Pedro; Barceló, Juan; Poschenrieder, Charlotte

    2010-05-01

    Soil contamination by antimony is of increasing environmental concern due to the use of this amphoterous p-block element in many industrial applications such as flame retardant, electronics, alloys, rubber and textile industries. However, little is still known about the response of plants to antimony. Here we report on the accumulation of antimony and other potentially toxic elements (mainly As, Pb and Cu) in plants growing around a former antimony mine in the ribes Valley located in the Eastern Pyrenees (424078E, 4686100N alt. 1145 m.a.s.l) that was operating approximately between the years 1870 to 1960. The ore mineral veins are included in quartz gangue. The main ores were: Sulphides: Stibnite (Sb2S3), Pyrite (FeS2), Sphalerite (ZnS), Arsenopyrite (FeAs), Galenite (PbS), Chalcopyrite (CuFeS2), Tetrahydrite (Cu5Sb2S3). Sulphosals: Boulangerite (5PbS•2Sb2S3), Jamesonite (4PbS•FeS•3Sb2S3), Zinckenite (6PbS•7Sb2S3), Plagionite (5PbS•4Sb2S3), Bournonite PbCu (Sb,As)S3, Pyrargirite (Ag3SbS3). Soil and plant samples were taken at five locations with different levels of Sb, As, and polymetallic contamination. Both pseudototal (aqua regia soluble) and extractable (EDTA) concentrations of metals from sites with low (sites 1 and 2), moderate (site 3 and 4) and high (sites 5 and 6) pollutant burdens were studied. The range of agua regia and EDTA values in mgkg-1 is as follows: Sb 8-2904 and 0.88-44; As: 33-16186 and 3.2-167; Pb: 79-4794 and 49-397; Cu: 66-712 and 48-56 mg•kg-1, respectively). While sites 1 to 4 had alkaline soil pH (7.4-8.7), sites 5 and 6 were acidic with values of 6 and 4.6, respectively. Different herbaceous plant species (Poa annua, Echium vulgare, Sonchus asper, Barbera verna among others) at the low and moderately polluted sites were able to efficiently restrict Sb and As transport to shoots showing average concentration ranges between 5.5 and 23 mg/kg As and 1.21 mg/kg and 4.9 mg/kg Sb. However, at the highly polluted acidic sites (5 and

  15. Leishmania panamensis infection and antimonial drugs modulate expression of macrophage drug transporters and metabolizing enzymes: impact on intracellular parasite survival

    PubMed Central

    Gómez, Maria Adelaida; Navas, Adriana; Márquez, Ricardo; Rojas, Laura Jimena; Vargas, Deninson Alejandro; Blanco, Victor Manuel; Koren, Roni; Zilberstein, Dan; Saravia, Nancy Gore

    2014-01-01

    Objectives Treatment failure is multifactorial. Despite the importance of host cell drug transporters and metabolizing enzymes in the accumulation, distribution and metabolism of drugs targeting intracellular pathogens, their impact on the efficacy of antileishmanials is unknown. We examined the contribution of pharmacologically relevant determinants in human macrophages in the antimony-mediated killing of intracellular Leishmania panamensis and its relationship with the outcome of treatment with meglumine antimoniate. Methods Patients with cutaneous leishmaniasis who failed (n = 8) or responded (n = 8) to treatment were recruited. Gene expression profiling of pharmacological determinants in primary macrophages was evaluated by quantitative RT–PCR and correlated to the drug-mediated intracellular parasite killing. Functional validation was conducted through short hairpin RNA gene knockdown. Results Survival of L. panamensis after exposure to antimonials was significantly higher in macrophages from patients who failed treatment. Sixteen macrophage drug-response genes were modulated by infection and exposure to meglumine antimoniate. Correlation analyses of gene expression and intracellular parasite survival revealed the involvement of host cell metallothionein-2A and ABCB6 in the survival of Leishmania during exposure to antimonials. ABCB6 was functionally validated as a transporter of antimonial compounds localized in both the cell and phagolysosomal membranes of macrophages, revealing a novel mechanism of host cell-mediated regulation of intracellular drug exposure and parasite survival within phagocytes. Conclusions These results provide insight into host cell mechanisms regulating the intracellular exposure of Leishmania to antimonials and variations among individuals that impact parasite survival. Understanding of host cell determinants of intracellular pharmacokinetics/pharmacodynamics opens new avenues to improved drug efficacy for intracellular

  16. Sodium fluoroacetate poisoning.

    PubMed

    Proudfoot, Alex T; Bradberry, Sally M; Vale, J Allister

    2006-01-01

    Sodium fluoroacetate was introduced as a rodenticide in the US in 1946. However, its considerable efficacy against target species is offset by comparable toxicity to other mammals and, to a lesser extent, birds and its use as a general rodenticide was therefore severely curtailed by 1990. Currently, sodium fluoroacetate is licensed in the US for use against coyotes, which prey on sheep and goats, and in Australia and New Zealand to kill unwanted introduced species. The extreme toxicity of fluoroacetate to mammals and insects stems from its similarity to acetate, which has a pivotal role in cellular metabolism. Fluoroacetate combines with coenzyme A (CoA-SH) to form fluoroacetyl CoA, which can substitute for acetyl CoA in the tricarboxylic acid cycle and reacts with citrate synthase to produce fluorocitrate, a metabolite of which then binds very tightly to aconitase, thereby halting the cycle. Many of the features of fluoroacetate poisoning are, therefore, largely direct and indirect consequences of impaired oxidative metabolism. Energy production is reduced and intermediates of the tricarboxylic acid cycle subsequent to citrate are depleted. Among these is oxoglutarate, a precursor of glutamate, which is not only an excitatory neurotransmitter in the CNS but is also required for efficient removal of ammonia via the urea cycle. Increased ammonia concentrations may contribute to the incidence of seizures. Glutamate is also required for glutamine synthesis and glutamine depletion has been observed in the brain of fluoroacetate-poisoned rodents. Reduced cellular oxidative metabolism contributes to a lactic acidosis. Inability to oxidise fatty acids via the tricarboxylic acid cycle leads to ketone body accumulation and worsening acidosis. Adenosine triphosphate (ATP) depletion results in inhibition of high energy-consuming reactions such as gluconeogenesis. Fluoroacetate poisoning is associated with citrate accumulation in several tissues, including the brain. Fluoride

  17. The protective role of Nrf2-Gadd45b against antimony-induced oxidative stress and apoptosis in HEK293 cells.

    PubMed

    Jiang, Xingkang; An, Zesheng; Lu, Chao; Chen, Yue; Du, E; Qi, Shiyong; Yang, Kuo; Zhang, Zhihong; Xu, Yong

    2016-08-10

    Antimony (Sb) is one of the most prevalent heavy metals and frequently causes biological toxicity. However, the specific mechanisms by which Sb elicits its toxic effects remains to be fully elucidated. In this study, we found antimony trioxide (Sb2O3) caused a dose-dependent cytotoxicity against HEK293 cells, and Sb2O3-induced excessive reactive oxygen species (ROS) was closely correlated with increased cell apoptosis. Mechanistic investigation manifested that nuclear factor NF-E2-related factor 2 (Nrf2) expression and nuclear translocation were significantly induced under Sb2O3 treatment in HEK293 cells, and Nrf2 knockdown aggregated Sb2O3-induced cell apoptosis. Moreover, elevated Gadd45b expression actives the phosphorylation of MAPKs upon Sb2O3 exposure, whereas Gadd45b knockdown diminished Sb2O3-induced activation of MAPKs and promoted cell apoptosis. In the meantime, however, the antioxidant N-acetylcysteine (NAC) was found to ameliorate Nrf2 expression and nuclear translocation as well as Gadd45b expression and MAPKs activation by repressing Sb2O3-induced ROS production. More importantly, we found Gadd45b was transcriptionally enhanced by Nrf2 through binding to three canonical antioxidant response elements (AREs) within its promoter region. Either Sb2O3 or TBHQ (a selective Nrf2 activator) treatment, Gadd45b expression was significantly increased by luciferase assay. Nrf2 inhibition greatly diminished Gadd45b expression due to reduced binding of Nrf2 in Gadd45b promoter under Sb2O3 treatment. To summarize, this study demonstrated the Nrf2-Gadd45b signaling axis exhibited a protective role in Sb-induced cell apoptosis.

  18. Fractional excretion of sodium

    MedlinePlus

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  19. Sodium carbonate poisoning

    MedlinePlus

    Sodium carbonate (known as washing soda or soda ash) is a chemical found in many household and ... products. This article focuses on poisoning due to sodium carbonate. This article is for information only. Do ...

  20. Naproxen sodium overdose

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002507.htm Naproxen sodium overdose To use the sharing features on this page, please enable JavaScript. Naproxen sodium is a nonsteroidal anti-inflammatory drug (NSAID) used ...

  1. Sodium Ferric Gluconate Injection

    MedlinePlus

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  2. Sodium hydroxide poisoning

    MedlinePlus

    Sodium hydroxide is a very strong chemical. It is also known as lye and caustic soda. This ... poisoning from touching, breathing in (inhaling), or swallowing sodium hydroxide. This article is for information only. Do ...

  3. Diclofenac sodium overdose

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002630.htm Diclofenac sodium overdose To use the sharing features on this page, please enable JavaScript. Diclofenac sodium is a prescription medicine used to relieve pain ...

  4. Docusate Sodium and Pregnancy

    MedlinePlus

    ... live chat Live Help Fact Sheets Share Docusate Sodium Friday, 01 April 2016 In every pregnancy, a ... This sheet talks about whether exposure to docusate sodium may increase the risk for birth defects over ...

  5. Probing the mechanism of sodium ion insertion into copper antimony Cu2Sb anodes

    SciTech Connect

    Baggetto, Loic; Carroll, Kyler J.; Hah, Hien -Yoong; Johnson, Charles E.; Mullins, David R.; Unocic, Raymond R.; Johnson, Jacqueline A.; Meng, Ying Shirley; Veith, Gabriel M.

    2014-03-25

    Cycling Cu2Sb films with fluoroethylene carbonate additive drastically improves the capacity retention of the electrode compared to cycling in pure PC with about 250 mAh g-1 retained capacity for about two hundred cycles. TEM photographs reveal that the pristine films are formed of nanoparticles of 5-20 nm diameters. XRD results highlight that during the first discharge the reaction leads to the formation of Na3Sb via an intermediate amorphous phase. During charge, Na3Sb crystallites convert into an amorphous phase, which eventually crystallizes into Cu2Sb at full charge, indicating a high degree of structural reversibility. The subsequent discharge is marked by a new plateau around 0.5 V at low Na/Sb content which does not correspond to the formation of a crystalline phase. XAS data show that the fully discharged electrode material has interatomic distances matching those expected for the coexistence of Cu and Na3Sb nanodomains. At 1 V charge, the structure somewhat differs from that of Cu2Sb whereas at 2 V charge, when all Na is removed, the structure is significantly closer to that of the starting material. 121Sb Mössbauer spectroscopy isomer shifts of Cu2Sb powder (-9.67 mm s-1) and thin films (-9.65 mm s-1) are reported for the first time, and agree with the value predicted theoretically. At full discharge, an isomer shift (-8.10 mm s-1) rather close to that of a Na3Sb reference powder (-8.00 mm s-1) is measured, in agreement with the formation of Na3Sb domains evidenced by XRD and XAS data. As a result, the isomer shift at 1 V charge (-9.29 mm s-1) is close to that of the pristine material and the higher value is in agreement with the lack of full desodiation at 1 V.

  6. Chloride transport and the actions of nedocromil sodium and cromolyn sodium in asthma.

    PubMed

    Alton, E W; Norris, A A

    1996-11-01

    Nedocromil sodium has been shown to be capable of inhibiting chloride ion flux in mast cells, epithelial cells, and neurons. This feature may explain how it can prevent responses such as mast-cell degranulation, the effects of osmolarity changes in the airways, and neuronal activation. This mechanism may also provide a unifying hypothesis to explain the effects of nedocromil sodium on a range of cell types involved in asthma, such as sensory and efferent neurons and cells involved in inflammation.

  7. Clinical evaluation of nedocromil sodium in asthma.

    PubMed

    Holgate, S T

    1986-01-01

    The recognition that inflammatory events in the airways play a key role in the pathogenesis of asthma has led to a relentless search for pharmacological agents which modify these processes. Nedocromil sodium (Tilade) represents one such agent. Nedocromil sodium, when inhaled by patients with asthma (0.05-0.50% nebulized, 0.5-4.0 mg m.d.i.), has been shown to inhibit immediate bronchoconstriction provoked by challenges with allergen (10 studies), exercise (five studies), isocapnic hyperventilation, fog and sulphur dioxide (one study each) and adenosine (two studies). With these challenges, inhibition of bronchoconstriction exhibited dose-dependency up to 4 mg, with nedocromil sodium being up to four times more potent than sodium cromoglycate. When inhaled prior to allergen provocation, nedocromil sodium inhibited the late asthmatic reaction; when taken regularly during the pollen season, it attenuated the allergen-induced increase in non-specific bronchial responsiveness. The efficacy of nedocromil sodium (4 mg q.i.d.) in the treatment of clinical asthma was initially shown in four open studies and subsequently confirmed in nine double-blind, placebo-controlled 4-12 week studies on patients with seasonal and perennial asthma. Further clinical trials (eight studies) identified some difficulty in replacing inhaled corticosteroids with nedocromil sodium, especially if the corticosteroids were reduced rapidly (four studies). However, two studies have shown that nedocromil sodium produced further improvement in asthma symptoms when used in addition to bronchodilators and inhaled corticosteroids. Treatment with nedocromil sodium (4 mg q.i.d.) for up to 52 weeks demonstrated a progressive reduction in bronchodilator usage throughout the whole treatment period. During clinical assessment, nedocromil sodium was well tolerated, side-effects being unpleasant taste, nausea and headache. In most cases the adverse reactions were mild and transient, although in approximately 3% of

  8. Low sodium level

    MedlinePlus

    ... osmolality Urine sodium Treatment The cause of low sodium must be diagnosed and treated. If cancer is the cause of the condition, then radiation, chemotherapy , or surgery to remove the tumor may correct the sodium imbalance. Other treatments depend on the specific type ...

  9. Species-Specific Antimonial Sensitivity in Leishmania Is Driven by Post-Transcriptional Regulation of AQP1

    PubMed Central

    Mandal, Goutam; Mandal, Srotoswati; Sharma, Mansi; Charret, Karen Santos; Papadopoulou, Barbara; Bhattacharjee, Hiranmoy; Mukhopadhyay, Rita

    2015-01-01

    Leishmania is a digenetic protozoan parasite causing leishmaniasis in humans. The different clinical forms of leishmaniasis are caused by more than twenty species of Leishmania that are transmitted by nearly thirty species of phlebotomine sand flies. Pentavalent antimonials (such as Pentostam or Glucantime) are the first line drugs for treating leishmaniasis. Recent studies suggest that pentavalent antimony (Sb(V)) acts as a pro-drug, which is converted to the more active trivalent form (Sb(III)). However, sensitivity to trivalent antimony varies among different Leishmania species. In general, Leishmania species causing cutaneous leishmaniasis (CL) are more sensitive to Sb(III) than the species responsible for visceral leishmaniasis (VL). Leishmania aquaglyceroporin (AQP1) facilitates the adventitious passage of antimonite down a concentration gradient. In this study, we show that Leishmania species causing CL accumulate more antimonite, and therefore exhibit higher sensitivity to antimonials, than the species responsible for VL. This species-specific differential sensitivity to antimonite is directly proportional to the expression levels of AQP1 mRNA. We show that the stability of AQP1 mRNA in different Leishmania species is regulated by their respective 3’-untranslated regions. The differential regulation of AQP1 mRNA explains the distinct antimonial sensitivity of each species. PMID:25714343

  10. Development of an analytical method for antimony speciation in vegetables by HPLC-hydride generation-atomic fluorescence spectrometry.

    PubMed

    Olivares, David; Bravo, Manuel; Feldmann, Jorg; Raab, Andrea; Neaman, Alexander; Quiroz, Waldo

    2012-01-01

    A new method for antimony speciation in terrestrial edible vegetables (spinach, onions, and carrots) was developed using HPLC with hydride generation-atomic fluorescence spectrometry. Mechanical agitation and ultrasound were tested as extraction techniques. Different extraction reagents were evaluated and optimal conditions were determined using experimental design methodology, where EDTA (10 mmol/L, pH 2.5) was selected because this chelate solution produced the highest extraction yield and exhibited the best compatibility with the mobile phase. The results demonstrated that EDTA prevents oxidation of Sb(III) to Sb(V) and maintains the stability of antimony species during the entire analytical process. The LOD and precision (RSD values obtained) for Sb(V), Sb(III), and trimethyl Sb(V) were 0.08, 0.07, and 0.9 microg/L and 5.0, 5.2, and 4.7%, respectively, for a 100 microL sample volume. The application of this method to real samples allowed extraction of 50% of total antimony content from spinach, while antimony extracted from carrots and onion samples ranged between 50 and 60 and 54 and 70%, respectively. Only Sb(V) was detected in three roots (onion and spinach) that represented 60-70% of the total antimony in the extracts.

  11. Sodium in feline nutrition.

    PubMed

    Nguyen, P; Reynolds, B; Zentek, J; Paßlack, N; Leray, V

    2016-08-23

    High sodium levels in cat food have been controversial for a long time. Nonetheless, high sodium levels are used to enhance water intake and urine volume, with the main objective of reducing the risk of urolithiasis. This article is a review of current evidence of the putative risks and benefits of high dietary sodium levels. Its secondary aim is to report a possible safe upper limit (SUL) for sodium intake. The first part of the manuscript is dedicated to sodium physiology, with a focus on the mechanisms of sodium homeostasis. In this respect, there is only few information regarding possible interactions with other minerals. Next, the authors address how sodium intake affects sodium balance; knowledge of these effects is critical to establish recommendations for sodium feed content. The authors then review the consequences of changes in sodium intake on feline health, including urolithiasis, blood pressure changes, cardiovascular alterations and kidney disease. According to recent, long-term studies, there is no evidence of any deleterious effect of dietary sodium levels as high as 740 mg/MJ metabolizable energy, which can therefore be considered the SUL based on current knowledge.

  12. Responses and acclimation of Chinese cork oak (Quercus variabilis Bl.) to metal stress: the inducible antimony tolerance in oak trees.

    PubMed

    Zhao, Xiulian; Zheng, Lingyu; Xia, Xinli; Yin, Weilun; Lei, Jingpin; Shi, Shengqing; Shi, Xiang; Li, Huiqing; Li, Qinghe; Wei, Yuan; Chang, Ermei; Jiang, Zeping; Liu, Jianfeng

    2015-08-01

    Antimony (Sb) pollution has become a pressing environmental problem in recent years. Trees have been proven to have great potential for the feasible phytomanagement; however, little is known about Sb retention and tolerance in trees. The Chinese cork oak (Quercus variabilis Bl.) is known to be capable of growth in soils containing high concentrations of Sb. This study explored in detail the retention and acclimation of Q. variabilis under moderate and high external Sb levels. Results revealed that Q. variabilis could tolerate and accumulate high Sb (1623.39 mg kg(-1) DW) in roots. Dynamics of Sb retention in leaves, stems, and roots of Q. variabilis were different. Leaf Sb remained at a certain level for several weeks, while in roots and stems, Sb concentrations continued to increase. Sb damaged tree's PSII reaction cores but elicited defense mechanism at the donor side of PSII. It affected the electron transport flow after QA (-) more strongly than the oxygen-evolving complex and light-harvesting pigment-protein complex II. Sb also decreased leaf chlorophyll concentrations and therefore inhibited plant growth. During acclimation to Sb toxicity, Sb concentrations in leaves, stems, and roots decreased, with photosynthetic activity and pigments recovering to normal levels by the end of the experiment. These findings suggest that Sb tolerance in Q. variabilis is inducible. Acclimation seems to be related to homeostasis of Sb in plants. Results of this study can provide useful information for trees breeding and selection of Sb phytomanagement strategies, exploiting the established ability of Q. variabilis to transport, delocalize in the leaves, and tolerate Sb pollutions.

  13. Speciation of very low amounts of arsenic and antimony in waters using dispersive liquid-liquid microextraction and electrothermal atomic absorption spectrometry

    NASA Astrophysics Data System (ADS)

    Rivas, Ricardo E.; López-García, Ignacio; Hernández-Córdoba, Manuel

    2009-04-01

    A new procedure for the determination of inorganic arsenic (III,V) and antimony (III,V) in water samples by dispersive liquid-liquid micro extraction separation and electrothermal atomic absorption spectrometry (ETAAS) is presented. At pH 1, As(III) and Sb(III) are complexed with ammonium pyrrolidine dithiocarbamate and extracted into the fine droplets formed when mixing carbon tetrachloride (extraction solvent), methanol (disperser solvent) and the sample solution. After extraction, the phases are separated by centrifugation, and As(III) and Sb(III) are determined in the organic phase. As(V) and Sb(V) remain in the aqueous layer. Total inorganic As and Sb are determined after the reduction of the pentavalent forms with sodium thiosulphate. As(V) and Sb(V) are calculated by difference. The detection limits are 0.01 and 0.05 µg L - 1 for As(III) and Sb(III), respectively, with an enrichment factor of 115. The relative standard deviation is in the 2.9-4.5% range. The procedure has been applied to the speciation of inorganic As and Sb in bottled, tap and sea water samples with satisfactory results.

  14. Pharmacokinetics of meglumine antimoniate after administration of a multiple dose in dogs experimentally infected with Leishmania infantum.

    PubMed

    Valladares, J E; Riera, C; Alberola, J; Gállego, M; Portús, M; Cristòfol, C; Franquelo, C; Arboix, M

    1998-02-15

    Pharmacokinetics of meglumine antimoniate in dogs with experimentally induced leishmaniosis has been investigated. After infection, dogs received a dose of 75 mg kg-1 of meglumine antimoniate twice daily by subcutaneous injection for 10 days. Blood samples were collected throughout the treatment. No statistical differences were found in the kinetic behaviour of the drug administered as a single dose to healthy dogs and that administered as a multiple dose to infected animals. However, peak plasma concentrations (Cmax) of 30.8 +/- 12.8 micrograms ml-1 found after this dosage regimen were higher than those observed after the single dose administration of 100 mg kg-1 24 h-1. Furthermore, sustained antimony concentrations of 1.14 +/- 0.52 micrograms Sb ml-1 were detected throughout the treatment. No signs of toxicity were found in the animals treated indicating that this regimen would be very appropriate to treat canine leishmaniosis.

  15. Analytical application of nano-sized titanium dioxide for the determination of trace inorganic antimony in natural waters.

    PubMed

    Hagarová, Ingrid; Matúš, Peter; Bujdoš, Marek; Kubová, Jana

    2012-03-01

    In this work, solid phase extraction (SPE) using nano-sized TiO2 as a solid sorbent was used for separation/preconcentration of total inorganic antimony (iSb) before its determination by electrothermal atomic absorption spectrometry (ETAAS). After adsorption of iSb onto nano-sized TiO2, direct TiO2-slurry sampling was used for sample injection into a graphite tube. The conditions for the reliable slurry sampling together with careful control of the temperature program for the slurry solutions were worked out. Extraction conditions for both inorganic antimony species (Sb(III) and Sb(V)) and interference studies of coexisting ions were studied in detail. The accuracy of the optimized method was checked by the certified reference material (CRM) for trace elements in lake water TMDA-61. Finally, the optimized method was used for the determination of trace inorganic antimony in synthetic and natural waters.

  16. Penicillamine as an adjuvant to antimonial therapy of schistosomiasis: effect on liver function tests in rabbits and on antischistosomal activity*

    PubMed Central

    Khayyal, M. T.; Saleh, S.; El Masri, A. M.

    1973-01-01

    Earlier work has shown that penicillamine reduces the acute toxicity of antimonyl potassium tartrate (APT) as well as the abnormal ECG changes it induces. In the present study, the possible protective effect of penicillamine on the hepatic toxicity of APT was investigated. Tests of liver function showed changes in the level of serum aspartate and alanine aminotransferase and of alkaline phosphatase, and in the beta-/alpha-lipoprotein ratio, in response to antimony treatment. The changes were significantly reduced by penicillamine, though the effect depended on the dose. Penicillamine was found to give the best overall protection without affecting the antischistosomal efficacy of the antimonial when a 1:2 APT/penicillamine ratio was used. The findings provide further evidence of the potential usefulness of penicillamine in the antimonial treatment of schistosomiasis. PMID:4543547

  17. Field-portable-XRF reveals the ubiquity of antimony in plastic consumer products.

    PubMed

    Turner, Andrew; Filella, Montserrat

    2017-02-09

    Very little systematic information exists on the occurrence and concentrations of antimony (Sb) in consumer products. In this study, a Niton XL3t field-portable-X-ray fluorescence (FP-XRF) spectrometer was deployed in situ and in the laboratory to provide quantitative information on Sb dissipated in plastic items and fixtures (including rubber, textile and foamed materials) from the domestic, school, vehicular and office settings. The metalloid was detected in 18% of over 800 measurements performed, with concentrations ranging from about 60 to 60,000μgg(-1). The highest concentrations were encountered in white, electronic casings and in association with similar concentrations of Br, consistent with the use of antimony oxides (e.g. Sb2O3) as synergistic flame retardants. Concentrations above 1000μgg(-1), and with or without Br, were also encountered in paints, piping and hosing, adhesives, whiteboards, Christmas decorations, Lego blocks, document carriers, garden furniture, upholstered products and interior panels of private motor vehicles. Lower concentrations of Sb were encountered in a wide variety of items but its presence (without Br) in food tray packaging, single-use drinks bottles, straws and small toys were of greatest concern from a human health perspective. While the latter observations are consistent with the use of antimony compounds as catalysts in the production of polyethylene terephthalate, co-association of Sb and Br in many products not requiring flame retardancy suggests that electronic casings are widely recycled. Further research is required into the mobility of Sb when dissipated in new, recycled and aged polymeric materials.

  18. Lithium-antimony-lead liquid metal battery for grid-level energy storage

    NASA Astrophysics Data System (ADS)

    Wang, Kangli; Jiang, Kai; Chung, Brice; Ouchi, Takanari; Burke, Paul J.; Boysen, Dane A.; Bradwell, David J.; Kim, Hojong; Muecke, Ulrich; Sadoway, Donald R.

    2014-10-01

    The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this finding

  19. Tissue distribution of trivalent antimony in mice infected with Schistosoma mansoni

    PubMed Central

    Molokhia, M. M.; Smith, H.

    1969-01-01

    The work described in this paper is designed to use the very high analytical sensitivity of neutron-activation analysis. The antimony content of individual organs and pieces of organs have been analysed as part of an investigation of the chemotherapy of schistosomiasis. The results illustrate the great, and as yet relatively unapplied, value of this technique in dealing with the investigation of trace elements in biological systems. Values such as those given form firm bases on which further studies can be built and show that the single animal has the same metabolic reactions as those deduced from bulked samples, but of course with individual variations. PMID:5306316

  20. Pharmacokinetics of experimental pentavalent antimony after intramuscular administration in adult volunteers*

    PubMed Central

    Vásquez, Laura; Scorza Dagert, José V.; Scorza, José V.; Vicuña-Fernández, Nelson; de Peña, Yaneira Petit; López, Sabrina; Bendezú, Herminia; Rojas, Elina; Vásquez, Libia; Pérez, Belén

    2006-01-01

    Background: Pentavalent antimony (SbV) has demonstrated therapeuticeffectiveness against clinical manifestations of leishmaniasis, an infection caused by Leishmania, a genus of flagellate protozoa comprising parasites of worldwide distribution. Approximately 1.8 million new cases are reported annually. Objective: The aim of this study was to assess the pharmacokinetics of the investigational generic SbV, Ulamina (pentachloride of antimony + N-methylglucamine), in healthy adult volunteers. Methods: In this study, SbV was administered IM as a single 5-mg/kg dose.Blood samples were collected at 0.25, 0.75, 1, 2, 4, 8, 12, and 24 hours after administration; urine samples were collected at 6-hour intervals during the 24-hour postadministration period. Determination of trivalent antimony, SbV, and total antimony concentrations in blood and urine samples was carried out using atomic absorption spectrometry. Clinical history was reviewed and the subjects were monitored before and after administration of SbV using physical examination, weight, and hepatic- and renal-function studies. The pharmacokinetic parameters calculated were Cmax, Tmax, absorption constant (Ka), elimination constant (Kel), AUC2–24h, AUC0-∞, elimination phase (t½β), volume of distribution (Vd), and urinary excretion rate. Results: Five subjects (3 men, 2 women; mean age, 28 years [range, 18–34 years]) were included in the study. One hour after drug administration the following values were obtained: Cmax, 1.1 μg/mL; Tmax, 1.3 hours; Ka, 1.87 hours; Kel, 0.043 hours; AUC0–24h, 12.26 μg/mL · h; AUC0-∞, 19.84 μg/mL · h; t½β, 17.45 hours; Vd, 6.6 L/kg; and urinary excretion rate, 2.8 μg/h; these were mean values for the entire study group. The single dose was well tolerated by all subjects. Conclusions: The investigational generic SbV, Ulamina, was associated with linearelimination after IM administration of a single 5-mg/kg dose. A 2-compartment pharmacokinetic model was observed in

  1. Stripping voltammetric determination of mercury(II) at antimony-coated carbon paste electrode.

    PubMed

    Ashrafi, Amir M; Vytřas, Karel

    2011-10-15

    A new procedure was elaborated to determine mercury(II) using an anodic stripping square-wave voltammetry at the antimony film carbon paste electrode (SbF-CPE). In highly acidic medium of 1M hydrochloric acid, voltammetric measurements can be realized in a wide potential window. Presence of cadmium(II) allows to separate peaks of Hg(II) and Sb(III) and apparently catalyses reoxidation of electrolytically accumulated mercury, thus allowing its determination at ppb levels. Calibration dependence was linear up to 100 ppb Hg with a detection limit of 1.3 ppb. Applicability of the method was tested on the real river water sample.

  2. Antimony oxofluorides - a synthesis concept that yields phase pure samples and single crystals.

    PubMed

    Ali, Sk Imran; Johnsson, Mats

    2016-07-26

    The single crystals of the new isostructural compounds Sb3O4F and Y0.5Sb2.5O4F and the two previously known compounds M-SbOF and α-Sb3O2F5 were successfully grown by a hydrothermal technique at 230 °C. The new compound Sb3O4F crystallizes in the monoclinic space group P21/c; a = 5.6107(5) Å, b = 4.6847(5) Å, c = 20.2256(18) Å, β = 94.145(8)°, z = 4. The replacing part of Sb with Y means a slight increase in the unit cell dimensions. The compounds M-SbOF and α-Sb3O2F5 have not been grown as single crystals before and it can be concluded that hydrothermal synthesis has proved to be a suitable technique for growing single crystals of antimony oxofluorides because of the relatively low solubility of such compounds compared to other antimony oxohalides that most often have been synthesised at high temperatures by solid state reactions or gas-solid reactions.

  3. Effect of indium and antimony doping in SnS single crystals

    SciTech Connect

    Chaki, Sunil H. Chaudhary, Mahesh D.; Deshpande, M.P.

    2015-03-15

    Highlights: • Single crystals growth of pure SnS, indium doped SnS and antimony doped SnS by direct vapour transport (DVT) technique. • Doping of In and Sb occurred in SnS single crystals by cation replacement. • The replacement mechanism ascertained by EDAX, XRD and substantiated by Raman spectra analysis. • Dopants concentration affects the optical energy bandgap. • Doping influences electrical transport properties. - Abstract: Single crystals of pure SnS, indium (In) doped SnS and antimony (Sb) doped SnS were grown by direct vapour transport (DVT) technique. Two doping concentrations of 5% and 15% each were employed for both In and Sb dopants. Thus in total five samples were studied viz., pure SnS (S1), 5% In doped SnS (S2), 15% In doped SnS (S3), 5% Sb doped SnS (S4) and 15% Sb doped SnS (S5). The grown single crystal samples were characterized by evaluating their surface microstructure, stoichiometric composition, crystal structure, Raman spectroscopy, optical and electrical transport properties using appropriate techniques. The d.c. electrical resistivity and thermoelectric power variations with temperature showed semiconducting and p-type nature of the as-grown single crystal samples. The room temperature Hall Effect measurements further substantiated the semiconducting and p-type nature of the as-grown single crystal samples. The obtained results are deliberated in detail.

  4. Application of Hyphenated Techniques in Speciation Analysis of Arsenic, Antimony, and Thallium

    PubMed Central

    Michalski, Rajmund; Szopa, Sebastian; Jabłońska, Magdalena; Łyko, Aleksandra

    2012-01-01

    Due to the fact that metals and metalloids have a strong impact on the environment, the methods of their determination and speciation have received special attention in recent years. Arsenic, antimony, and thallium are important examples of such toxic elements. Their speciation is especially important in the environmental and biomedical fields because of their toxicity, bioavailability, and reactivity. Recently, speciation analytics has been playing a unique role in the studies of biogeochemical cycles of chemical compounds, determination of toxicity and ecotoxicity of selected elements, quality control of food products, control of medicines and pharmaceutical products, technological process control, research on the impact of technological installation on the environment, examination of occupational exposure, and clinical analysis. Conventional methods are usually labor intensive, time consuming, and susceptible to interferences. The hyphenated techniques, in which separation method is coupled with multidimensional detectors, have become useful alternatives. The main advantages of those techniques consist in extremely low detection and quantification limits, insignificant interference, influence as well as high precision and repeatability of the determinations. In view of their importance, the present work overviews and discusses different hyphenated techniques used for arsenic, antimony, and thallium species analysis, in different clinical, environmental and food matrices. PMID:22654649

  5. [Liposomal amphotericin B treatment of cutaneous leishmaniasis contracted in Djibouti and resistant to meglumine antimoniate].

    PubMed

    Rapp, C; Imbert, P; Darie, H; Simon, F; Gros, P; Debord, T; Roué, R

    2003-08-01

    Pentavalent antimony (PA) compounds remain the main therapeutic agents of cutaneous leishmaniasis (CL). CL infection resistant to PA is difficult to cure, limited by severe side effects and requiring a long course treatment of parenteral administration of recommended second line drugs. We report a case of CL unresponsive to meglumine antimoniate contracted in Djibouti, successfully treated with a short course treatment of AmBisome. In this case the subject had a recurrent thick crusted erythematous lesion on his left elbow associated with spreading micropapula on arms and thorax. The diagnosis of CL was confirmed by direct examination and genomic amplification by PCR of skin samples, cultures were negative. A short course treatment of parenteral AmBisome (18 mg/kg) has lead to clinical cure with no side effects and no relapse. In our hospital, the high cost of medication was counterbalanced by easiest administration, reduction of hospitalization duration, absence of adverse events and a gain of comfort. For this patient, a short course treatment of AmBisome proved to be a suitable alternative to traditional drugs used in CL resistant to PA.

  6. A Black Phosphate Conversion Coating on Steel Surface Using Antimony(III)-Tartrate as an Additive

    NASA Astrophysics Data System (ADS)

    Li, Feng; Wang, Guiping

    2016-05-01

    A novel black phosphate conversion coating was formed on steel surface through a Zn-Mn phosphating bath containing mainly ZnO, H3PO4, Mn(H2PO4)2, and Ca(NO3)2, where antimony(III)-tartrate was used as the blackening agent of phosphatization. The surface morphology and composition of the coating were characterized by scanning electron microscopy, energy dispersion spectroscopy, and x-ray photoelectron spectroscopy. Corrosion resistance of the coating was studied by potentiodynamic polarization curves and electrochemical impedance spectroscopy. The pH value of the solution had significant influence on the formation and corrosion resistance of the coating. The experimental results indicated that the Sb plays a vital role in the blackening of phosphate conversion coating. The optimal concentration of antimony(III)-tartrate in the phosphating bath used in this experiment was 1.0 g L-1, as higher values reduced the corrosion resistance of the coating. In addition, by saponification and oil seals, the corrosion duration of the black phosphate coating in a copper sulfate spot test can be as long as 20 min.

  7. Influence of phosphoric acid on the electrochemistry of lead electrodes in sulfuric acid electrolyte containing antimony

    NASA Astrophysics Data System (ADS)

    Venugopalan, S.

    The influence of phosphoric acid (0 to 40 g 1 -1) on the Pb/PbSO 4 reaction and the kinetics of hydrogen evolution on pure, smooth lead and lead alloy electrodes is studied via galvanostatic polarization in the linear and Tafel domains with and without antimony (0 to 10 mg 1 -1) addition to the H 2SO 4 (3 to 10 M) electrolyte. Phosphoric acid is found to offset significantly the adverse effect of antimony. H 3PO 4 is also found to increase the hydrogen overpotential without affecting the Pb/PbSO 4 reaction. This implies that the open-circuit corrosion of lead and the consequent hydrogen evolution rate on lead are reduced in the presence of H 3PO 4. The beneficial effects of H 3PO 4 additive are found to be optimum at around 20 g 1 -1. Suppression of hydrogen evolution on the negative electrode, a crucial criterion for sealed cell operation, can be achieved using a H 3PO 4 additive.

  8. Heterogeneous dislocation nucleation in single crystal copper-antimony solid-solution alloys

    NASA Astrophysics Data System (ADS)

    Rajgarhia, Rahul K.; Spearot, Douglas E.; Saxena, Ashok

    2009-07-01

    Molecular dynamics (MD) simulations are employed to study the partial dislocation nucleation process in single crystal copper with varying concentrations of antimony (0.0-2.0 at%Sb) under uniaxial tension. A well-established embedded-atom method potential is used to represent the Cu-Cu interactions and a recently developed Lennard-Jones potential is used for the Cu-Sb and Sb-Sb interactions. Antimony atoms are randomly distributed as substitutional defects in the Cu single crystal. MD simulations indicate that the tensile stress required for partial dislocation nucleation in the crystal decreases with increasing concentration of Sb. The strain field around Sb dopant atoms in the Cu lattice reduces the unstable stacking fault energy, which promotes heterogeneous nucleation of partial dislocations and reduces the tensile stresses required for plastic deformation. In addition, the role of Sb on the reduction in the stress required for dislocation nucleation is found to be orientation-dependent. Finally, both temperature and Sb distribution play a role in the statistical variation of the stress required for heterogeneous partial dislocation nucleation; this variation is maximum at moderate levels of Sb concentration (0.20-0.50 at%Sb).

  9. Measurements of spin life time of an antimony-bound electron in silicon

    NASA Astrophysics Data System (ADS)

    Lu, T. M.; Bishop, N. C.; Tracy, L. A.; Blume-Kohout, R.; Pluym, T.; Wendt, J. R.; Dominguez, J.; Lilly, M. P.; Carroll, M. S.

    2013-03-01

    We report our measurements of spin life time of an antimony-bound electron in silicon. The device is a double-top-gated silicon quantum dot with antimony atoms implanted near the quantum dot region. A donor charge transition is identified by observing a charge offset in the transport characteristics of the quantum dot. The tunnel rates on/off the donor are first characterized and a three-level pulse sequence is then used to measure the spin populations at different load-and-wait times in the presence of a fixed magnetic field. The spin life time is extracted from the exponential time dependence of the spin populations. A spin life time of 1.27 seconds is observed at B = 3.25 T. This work was performed, in part, at the Center for Integrated Nanotechnologies, a U.S. DOE, Office of Basic Energy Sciences user facility. The work was supported by the Sandia National Laboratories Directed Research and Development Program. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  10. Organically complexed iron enhances bioavailability of antimony to maize (Zea mays) seedlings in organic soils.

    PubMed

    Ptak, Corey; McBride, Murray

    2015-12-01

    Antimony (Sb) is a metalloid belonging to group 15 of the periodic table. Chemical similarities between arsenic (As) and Sb produce concerns about potential health effects of Sb and enrichment in the environment. Antimony is found in oxic environments predominately as an oxyanionic species, antimonite (Sb[OH](6-)). As a result of its net negative charge, Sb[OH](6-) was not initially predicted to have strong interactions with natural organic matter. Oxyanionic species could bind the negatively charged organic matter via a ternary complexation mechanism, in which cationic metals mediate the strong association between organic matter functional groups and oxyanions. However, these interactions are poorly understood in how they influence the bioavailability of oxyanionic contaminants to plants. Iron (Fe) additions to organic soils have been found to increase the number of organically complexed Fe sites suitable for Sb exchange, resulting in a reduced bioavailable fraction of Sb. The bioavailability of Sb to maize seedlings as a function of organically complexed Fe was examined using a greenhouse study. A significant increase in plant tissue Sb was observed as organically complexed Fe increased, which was not predicted by methods commonly used to assess bioavailable Sb. Extraction of soils with organic acids common to the maize rhizosphere suggested that organic acid exudation can readily mobilize Sb bound by organic Fe complexes.

  11. Migration of antimony from PET containers into regulated EU food simulants.

    PubMed

    Sánchez-Martínez, María; Pérez-Corona, Teresa; Cámara, Carmen; Madrid, Yolanda

    2013-11-15

    Antimony migration from polyethylene terephthalate (PET) containers into aqueous (distilled water, 3% acetic acid, 10% and 20% ethanol) and fatty food simulants (vegetable oil), as well as into vinegar, was studied. Test conditions were according to the recent European Regulation 10/2011 (EU, 2011). Sb migration was assayed by ICP-MS and HG-AFS. The results showed that Sb migration values ranged from 0.5 to 1.2μg Sb/l, which are far below the maximum permissible migration value for Sb, 40μg Sb/kg, (EU, Regulation 10/2011). Parameters as temperature and bottle re-use influence were studied. To assess toxicity, antimony speciation was performed by HPLC-ICP-MS and HG-AFS. While Sb(V) was the only species detected in aqueous simulants, an additional species (Sb-acetate complex) was measured in wine vinegar. Unlike most of the studies reported in the literature, migration tests were based on the application of the EU directive, which enables comparison and harmonisation of results.

  12. Structural and optical study on antimony-silicate glasses doped with thulium ions.

    PubMed

    Dorosz, D; Zmojda, J; Kochanowicz, M; Miluski, P; Jelen, P; Sitarz, M

    2015-01-05

    Structural, spectroscopic and thermal properties of SiO₂-Al₂O₃-Sb₂O₃-Na₂O glass system doped with 0.2 mol% Tm₂O₃ have been presented. Synthesis of antimony-silicate glasses with relatively low phonon energy (600 cm(-1), which implicates a small non-radiative decay rate) was performed by conventional high-temperature melt-quenching methods. The effect of SiO₂/Sb₂O₃ ratio in fabricated Tm(3+) doped glass on thermal, structural and luminescence properties was investigated. On the basis of structural investigations decomposition of absorption bands in the infrared FTIR region was performed, thus determining that antimony ions are the only glass-forming ions, setting up the lattice of fabricated glasses. Luminescence band at the wavelength of 1.8 μm corresponding to (3)F₄→(3)H₆ transition in thulium ions was obtained under 795 nm laser pumping. It was observed that combination of relatively low phonon energy and greater separation of optically active centers in the fabricated glasses influenced in decreasing the luminescence intensity at 1800 nm.

  13. Evaluation of antimony microparticles supported on biochar for application in the voltammetric determination of paraquat.

    PubMed

    Gevaerd, Ava; de Oliveira, Paulo R; Mangrich, Antonio S; Bergamini, Márcio F; Marcolino-Junior, Luiz H

    2016-05-01

    This work describes the construction and application of carbon paste electrodes modified with biochar and antimony microparticles (SbBCPE) for voltammetric determination of paraquat using a simple and sensitive procedure based on voltammetric stripping analysis. Some parameters such as amount of biochar and antimony used in the composition of the carbon paste and instrumental parameters were examined in detail. Under optimized conditions, an analytical curve was obtained for paraquat determination employing SbBCPE, which showed a linear response ranging from 0.2 to 2.9 μmol L(-1), with limit of detection and quantification of 34 nmol L(-1) and 113 nmol L(-1), respectively, after paraquat pre-concentration of 120 s. The repeatability study presented a RSD=2.0% for 10 consecutive measurements using the same electrode surface and the reproducibility study showed a RSD=2.7% for measurements with 10 different electrode surfaces. The proposed sensor was successfully applied for paraquat determination in tap water and citric fruit juice spiked samples and good recoveries were obtained without any sample pre-treatment, showing its promising analytical performance.

  14. Dissolution and ionization of sodium superoxide in sodium-oxygen batteries

    NASA Astrophysics Data System (ADS)

    Kim, Jinsoo; Park, Hyeokjun; Lee, Byungju; Seong, Won Mo; Lim, Hee-Dae; Bae, Youngjoon; Kim, Haegyeom; Kim, Won Keun; Ryu, Kyoung Han; Kang, Kisuk

    2016-02-01

    With the demand for high-energy-storage devices, the rechargeable metal-oxygen battery has attracted attention recently. Sodium-oxygen batteries have been regarded as the most promising candidates because of their lower-charge overpotential compared with that of lithium-oxygen system. However, conflicting observations with different discharge products have inhibited the understanding of precise reactions in the battery. Here we demonstrate that the competition between the electrochemical and chemical reactions in sodium-oxygen batteries leads to the dissolution and ionization of sodium superoxide, liberating superoxide anion and triggering the formation of sodium peroxide dihydrate (Na2O2.2H2O). On the formation of Na2O2.2H2O, the charge overpotential of sodium-oxygen cells significantly increases. This verification addresses the origin of conflicting discharge products and overpotentials observed in sodium-oxygen systems. Our proposed model provides guidelines to help direct the reactions in sodium-oxygen batteries to achieve high efficiency and rechargeability.

  15. Two successive single crystal phase transitions involving the coordination sphere of antimony in PhSb(dmit), the first organo-antimony(III) dithiolene complex.

    PubMed

    Avarvari, N; Faulques, E; Fourmigué, M

    2001-05-21

    PhSb(dmit) (dmit(2)(-), 4,5-dithiolato-1,3-dithiole-2-thione), the first neutral organo-antimony dithiolene complex, has been synthesized by addition of PhSbCl(2) on a suspension of Na(2)(dmit). The complex was characterized by spectroscopic ((1)H and (13)C NMR and IR) methods and elemental analysis. Its crystal structure was determined by X-ray diffraction at room temperature in the monoclinic P2(1)/c space group, with a = 12.580(3), b = 8.9756(18), c = 15.905(3) A, beta = 109.06(3) degrees, V = 1697.5(6) A(3), Z = 4. A coordinating THF molecule was found in the structure and the coordination geometry around the antimony atom is of distorted pseudopentagonal bipyramid type, if taking into account the Sb.O and secondary Sb.S interactions, as well as the stereochemically active 5s(2) lone pair. The intermolecular Sb.S and S.S contacts, shorter than the sum of van der Waals radii of corresponding atoms, lead to the formation of a three-dimensional polymeric network in the solid state. A second X-ray diffraction experiment, performed at 85 K, revealed a very similar monoclinic unit cell with the noncentrosymmetrical space group P2(1) with a = 12.613(3), b = 8.9876(18), c = 15.109(3) A, beta = 107.01(3) degrees, V = 1637.8(6), Z = 4. The structural differences with the first one are basically due to the rotation of the THF ligand in the coordination sphere of the antimony center, leading to the loss of every inversion center found at room temperature. A temperature variable X-ray diffraction study on a PhSb(dmit) single-crystal allowed the detection, with a remarkable accuracy, of two successive first-order phase transitions, the first occurring at T = 162.5 K, while the second was observed at T = 182.5 K. Subsequently, a third set of X-ray data was collected at 180 K and the resulting structure (monoclinic, P2(1)/c, a = 16.736(3), b = 8.9653(18), c = 33.132(7) A, beta = 91.98(3) degrees, V = 4968.2(17), Z = 12) derives from the two others by a common b axis, a 3-fold

  16. Chemical vapor generation for sample introduction into inductively coupled plasma atomic emission spectroscopy: vaporization of antimony(III) with bromide.

    PubMed

    Lopez-Molinero, A; Mendoza, O; Callizo, A; Chamorro, P; Castillo, J R

    2002-10-01

    A new method for antimony determination in soils is proposed. It is based on the chemical vapor generation of Sb(III) with bromide, after a reaction in sulfuric acid media and transport of the gaseous phase into an inductively coupled plasma for atomic emission spectrometry. The experimental variables influencing the method were delimited by experimental design and the most important were finally optimized by the modified Simplex method. In optimized conditions the method involves the reaction of 579 microl concentrated sulfuric acid with 120 microl 5% w/v KBr and 250 microl antimony solution. Measurement of antimony emission intensity at 217.581 nm provides a method with an absolute detection limit of 3.5 ng and a precision (RSD) of 5.8% for the injection of five replicates of 175 ng Sb(III) (250 microl of 0.7 microg ml(-1) solution). The interference of common anions and cations on the antimony signal was evaluated. A 21% Sb(III) volatilization efficiency was calculated from the mean of six experiments at optimum conditions. The accuracy of the methodology was checked by the analysis of one standard reference soil after acid decomposition heating in a microwave oven.

  17. Identification of antimony resistance markers in Leishmania tropica field isolates through a cDNA-AFLP approach.

    PubMed

    Kazemi-Rad, Elham; Mohebali, Mehdi; Khadem-Erfan, Mohammad Bagher; Saffari, Mojtaba; Raoofian, Reza; Hajjaran, Homa; Hadighi, Ramtin; Khamesipour, Ali; Rezaie, Sassan; Abedkhojasteh, Hoda; Heidari, Mansour

    2013-10-01

    Pentavalent antimonial compounds have been the first line therapy for leishmaniasis; unfortunately the rate of treatment failure of anthroponotic cutaneous leishmaniasis (ACL) is increasing due to emerging of drug resistance. Elucidation of the molecular mechanisms operating in antimony resistance is critical for development of new strategies for treatment. Here, we used a cDNA-AFLP approach to identify gene(s) which are differentially expressed in resistant and sensitive Leishmania tropica field isolates. We identified five genes, aquaglyceroporin (AQP1) acts in drug uptake, ATP-binding cassette (ABC) transporter (MRPA) involved in sequestration of drug, phosphoglycerate kinase (PGK) implicated in glycolysis metabolism, mitogen activated protein kinase (MAPK) and protein tyrosine phosphatase (PTP) responsible for phosphorylation pathway. The results were confirmed using real time RT-PCR which revealed an upregulation of MRPA, PTP and PGK genes and downregulation of AQP1 and MAPK genes in resistant isolate. To our knowledge, this is the first report of identification of PTP and PGK genes potentially implicated in resistance to antimonials. Our findings support the idea that distinct biomolecules might be involved in antimony resistance in L. tropica field isolates.

  18. Successful treatment of imported mucosal Leishmania infantum leishmaniasis with miltefosine after severe hypokalemia under meglumine antimoniate treatment.

    PubMed

    Neumayr, Andreas L C; Walter, Clemens; Stoeckle, Marcel; Braendle, Natalie; Glatz, Kathrin; Blum, Johannes A

    2012-01-01

    Old World mucosal leishmaniasis is a rare but regularly reported disease in Southern Europe. We report the case of a 64-year-old woman who developed severe hypokalemia under meglumine antimoniate treatment and was successfully treated under second line therapy with miltefosine.

  19. An emerging antiarrhythmic target: late sodium current.

    PubMed

    Banyasz, T; Szentandrássy, N; Magyar, J; Szabo, Z; Nánási, P P; Chen-Izu, Y; Izu, L T

    2015-01-01

    The cardiac late sodium current (INa,L) has been in the focus of research in the recent decade. The first reports on the sustained component of voltage activated sodium current date back to the seventies, but early studies interpreted this tiny current as a product of a few channels that fail to inactivate, having neither physiologic nor pathologic implications. Recently, the cardiac INa,L has emerged as a potentially major arrhythmogenic mechanism in various heart diseases, attracting the attention of clinicians and researchers. Research activity on INa,L has exponentially increased since Ranolazine, an FDA-approved antianginal drug was shown to successfully suppress cardiac arrhythmias by inhibiting INa,L. This review aims to summarize and discuss a series of papers focusing on the cardiac late sodium current and its regulation under physiological and pathological conditions. We will discuss critical evidences implicating INa,L as a potential target for treating myocardial dysfunction and cardiac arrhythmias.

  20. Decode the Sodium Label Lingo

    MedlinePlus

    ... For Preschooler For Gradeschooler For Teen Decode the Sodium Label Lingo Published January 24, 2013 Print Email Reading food labels can help you slash sodium. Here's how to decipher them. "Sodium free" or " ...

  1. Mercury's sodium exosphere

    NASA Astrophysics Data System (ADS)

    Leblanc, F.; Johnson, R. E.

    2003-08-01

    Mercury's neutral sodium exosphere is simulated using a comprehensive 3D Monte Carlo model following sodium atoms ejected from Mercury's surface by thermal desorption, photon stimulated desorption, micro-meteoroid vaporization and solar wind sputtering. The evolution of the sodium surface density with respect to Mercury's rotation and its motion around the Sun is taken into account by considering enrichment processes due to surface trapping of neutrals and ions and depletion of the sodium available for ejection from the surfaces of grains. The change in the sodium exosphere is calculated during one Mercury year taking into account the variations in the solar radiation pressure, the photo-ionization frequency, the solar wind density, the photon and meteoroid flux intensities, and the surface temperature. Line-of-sight column densities at different phase angles, the supply rate of new sodium, average neutral and ion losses over a Mercury year, surface density distribution and the importance of the different processes of ejection are discussed in this paper. The sodium surface density distribution is found to become significantly nonuniform from day to night sides, from low to high latitudes and from morning to afternoon because of rapid depletion of sodium atoms in the surfaces of grains mainly driven by thermal depletion. The shape of the exosphere, as it would be seen from the Earth, changes drastically with respect to Mercury's heliocentric position. High latitude column density maxima are related to maxima in the sodium surface concentration at high latitudes in Mercury's surface and are not necessarily due to solar wind sputtering. The ratio between the sodium column density on the morning side of Mercury's exosphere and the sodium column density on the afternoon side is consistent with the conclusions of Sprague et al. (1997, Icarus 129, 506-527). The model, which has no fitting parameters, shows surprisingly good agreement with recent observations of Potter et

  2. METHOD FOR REMOVING SODIUM OXIDE FROM LIQUID SODIUM

    DOEpatents

    Bruggeman, W.H.; Voorhees, B.G.

    1957-12-01

    A method is described for removing sodium oxide from a fluent stream of liquid sodium by coldtrapping the sodium oxide. Apparatus utilizing this method is disclosed in United States Patent No. 2,745,552. Sodium will remain in a molten state at temperatures below that at which sodium oxide will crystallize out and form solid deposits, therefore, the contaminated stream of sodium is cooled to a temperature at which the solubility of sodium oxide in sodium is substantially decreased. Thereafter the stream of sodium is passed through a bed of stainless steel wool maintained at a temperature below that of the stream. The stream is kept in contact with the wool until the sodium oxide is removed by crystal growth on the wool, then the stream is reheated and returned to the system. This method is useful in purifying reactor coolants where the sodium oxide would otherwise deposit out on the walls and eventually plug the coolant tubes.

  3. Lithium-antimony-lead liquid metal battery for grid-level energy storage.

    PubMed

    Wang, Kangli; Jiang, Kai; Chung, Brice; Ouchi, Takanari; Burke, Paul J; Boysen, Dane A; Bradwell, David J; Kim, Hojong; Muecke, Ulrich; Sadoway, Donald R

    2014-10-16

    The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this

  4. Antimony and arsenic behaviours in soils from three abandoned gold mining areas in northern Portugal

    NASA Astrophysics Data System (ADS)

    Carvalho, Paula; Neiva, Ana; Silva, Maria

    2013-04-01

    The Valongo anticline located 18 km at East of Porto is characterized by the occurrence of several gold deposits, which were exploited until the end of the nineteenth century. This anticline comprises Cambrian to Carboniferous metasediments. The Cambrian schist-graywacke complex crops out in the western limb of the anticline and is intersected by several Sb-Au quartz veins, mainly Montalto and Tapada. At the eastern limb of the anticline, As-Au quartz veins cut Ordovician black slates and were exploited at the Banjas mine. The Sb-Au quartz veins contain mainly quartz, arsenopyrite, pyrrhotite, pyrite, marcasite, sphalerite, chalcophyrite, galena, gold, tetrahedrite, jamesonite, plagionite, berthierite, stibnite, antimony and carbonates. The As-Au quartz veins consist of quartz, arsenopyrite, pyrite, pyrrhotite, cobaltite, glaucodote, sphalerite, boulangerite, tetrahedrite and siderite. Stibnite and arsenopyrite are the most abundant sulphides in Sb-Au and As-Au quartz veins, respectively. Therefore, antimony and arsenic are potential contaminants in the surrounding environments of these old mines. The principal component analysis (PCA) was applied to organic matter, pH, cation exchange capacity, clay size particle and reducible, oxidizable and aqua regia Fe, Mn, As and Sb concentrations obtained by the BCR method in 29 soil samples. The PCA shows a substantial distinction between Sb and As behaviours in soils from the old mining areas of Montalto, Tapada and Banjas. The arsenic concentration ranges between 16.98 mg/kg and 1116 mg/kg, whereas the Sb concentration ranges from 6.4 mg/kg to 21775 mg/kg. The antimony is statistically more correlated with Fe and Mn in the oxides fraction, whereas As in the reducible fraction dependents on pH values. Moreover, Fe and Mn concentrations in the oxidizable fraction are highly correlated with the organic matter, suggesting that pyrite, the main host mineral of Fe, was probably totally altered. However, the As concentration in

  5. Submersible sodium pump

    DOEpatents

    Brynsvold, G.V.; Lopez, J.T.; Olich, E.E.; West, C.W.

    1989-11-21

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates. 14 figs.

  6. Submersible sodium pump

    DOEpatents

    Brynsvold, Glen V.; Lopez, John T.; Olich, Eugene E.; West, Calvin W.

    1989-01-01

    An electromagnetic submerged pump has an outer cylindrical stator with an inner cylindrical conductive core for the submerged pumping of sodium in the cylindrical interstitial volume defined between the stator and core. The cylindrical interstitial volume is typically vertically oriented, and defines an inlet at the bottom and an outlet at the top. The outer stator generates upwardly conveyed toroidal magnetic fields, which fields convey preferably from the bottom of the pump to the top of the pump liquid sodium in the cold leg of a sodium cooled nuclear reactor. The outer cylindrical stator has a vertically disposed duct surrounded by alternately stacked layers of coil units and laminates.

  7. SODIUM DEUTERIUM REACTOR

    DOEpatents

    Oppenheimer, E.D.; Weisberg, R.A.

    1963-02-26

    This patent relates to a barrier system for a sodium heavy water reactor capable of insuring absolute separation of the metal and water. Relatively cold D/sub 2/O moderator and reflector is contained in a calandria into which is immersed the fuel containing tubes. The fuel elements are cooled by the sodium which flows within the tubes and surrounds the fuel elements. The fuel containing tubes are surrounded by concentric barrier tubes forming annular spaces through which pass inert gases at substantially atmospheric pressure. Header rooms above and below the calandria are provided for supplying and withdrawing the sodium and inert gases in the calandria region. (AEC)

  8. Antimony speciation in soils: improving the detection limits using post-column pre-reduction hydride generation atomic fluorescence spectroscopy (HPLC/pre-reduction/HG-AFS).

    PubMed

    Quiroz, Waldo; Olivares, David; Bravo, Manuel; Feldmann, Jorg; Raab, Andrea

    2011-04-15

    HG-AFS is highly sensitive and low cost detection system and its use for antimony chemical speciation coupled to HPLC is gaining popularity. However speciation analysis in soils is strongly hampered because the most efficient extractant reported in the literature (oxalic acid) strongly inhibits the generation of SbH(3) by Sb(V), the major species in this kind of matrix, severely affecting its detection limits. The purpose of this research is to reduce the detection limit of Sb(V), by using a post column on-line reduction system with l-cysteine reagent (HPLC/pre-reduction/HG-AFS). The system was optimized by experimental design, optimum conditions found were 2% (w/v) and 10°C temperature coil. Detection limits of Sb(V) and Sb(III) in oxalic acid (0.25 mol L(-1)) were improved from 0.3 and 0.1 μg L(-1) to 0.07 and 0.07 μg L(-1), respectively. The methodology developed was applied to Chilean soils, where Sb(V) was the predominant species.

  9. Use of sodium polyaspartate for the removal of hydroxyapatite/brushite deposits from stainless steel tubing

    SciTech Connect

    Littlejohn, F.; Saez, A.E.; Grant, C.S.

    1998-07-01

    This research investigates the use of sodium polyaspartate, a nontoxic, biodegradable polycarboxylic sequestrant, for removing calcium phosphate deposit consisting of hydroxyapatite (HAP) and brushite or dicalcium phosphate dihydrate (DCPD) from stainless steel surfaces. Cleaning studies show that the use of sodium polyaspartate under alkaline conditions significantly enhances the removal rates when compared to deionized water. In acidic solutions, sodium polyaspartate concentrations below 300 ppm inhibit removal of HAP/DCPD deposits whereas higher concentrations increase the removal rate. Comparative cleaning studies at alkaline pHs show that sodium polyaspartate cleans the surface at a rate comparable to sodium citrate but slower than in ethylenediaminetetraacetic acid. Supplementary dissolution experiments show that sodium polyaspartate enhances the HAP/DCPD dissolution rate while inhibiting the release of Ca{sup 2+}. On the basis of these findings, the authors have concluded that sodium polyaspartate improves the HAP/DCPD dissolution and cleaning rates by Ca{sup 2+} sequestration.

  10. Sodium hypochlorite poisoning

    MedlinePlus

    ... poisoning, especially if the product is mixed with ammonia. This article is for information only. Do NOT ... hypochlorite, which may cause severe injury. NEVER mix ammonia with sodium hypochlorite (bleach or bleach-containing products). ...

  11. Sequential solvent extraction for forms of antimony in five selected coals

    USGS Publications Warehouse

    Qi, C.; Liu, Gaisheng; Kong, Y.; Chou, C.-L.; Wang, R.

    2008-01-01

    Abundance of antimony in bulk samples has been determined in five selected coals, three coals from Huaibei Coalfield, Anhui, China, and t