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Sample records for acido retinoico todo-trans

  1. Some Biochemical Properties of an Acido-Thermophilic Archae-Bacterium Sulfolobus Acidocaldarius

    NASA Astrophysics Data System (ADS)

    Oshima, Tairo; Ohba, Masayuki; Wagaki, Takayoshi

    1984-12-01

    To elucidate the phylogenic status of archaebacteria, some basic cellular components of an acido-thermophilic archaebacterium,Sulfolobus acidocaldarius, were studied. Poly(A) containing RNA was present in the cells, and performed the role of mRNA in a cell-free extract of reticulocyte or the archaebacteria. Poly(A) containing RNA was also found in other archaebacterial cells. The absence of cap structure was suggested in these RNAs. The cell-free protein synthesis using the archaebacterial extract was inhibited by anisomycin, a specific inhibitor for eukaryotic ribosomes. Two unique membrane-bound ATPases were detected. Based on resistance to H+-ATPase inhibitors, these enzymes seemed not to be F0F1-ATPase.

  2. Isolation and characterization of oligotrophic acido-tolerant methanogenic consortia from a Sphagnum peat bog.

    PubMed

    Sizova, Maria V; Panikov, Nicolai S; Tourova, Tatiana P; Flanagan, Patrick W

    2003-08-01

    Two dense and highly enriched (up to 10(9) cells ml(-1), <10% of bacterial satellites) acido-tolerant (pH 4.0-6.5) methanogenic consortia, '26' and 'K', were isolated from the peat beneath a Sphagnum-Eriophorum-Carex community in West Siberia. Both consortia produced methane from CO2:H2 on chemically defined, diluted N-free media containing Ti(III)citrate as reducing agent. The phylogenetic analysis of 16S ribosomal DNA revealed three archaeal and nine bacterial sequence types. Consortium '26' contained single archaea Methanobacterium sp., represented by rods of 1.5-10x0.5-1.0 microm. In consortium 'K', there were two archaeal phylotypes, the respective methanogens were further differentiated morphologically with the fluorescence in situ hybridization technique: one less abundant (<2%) population of the long-curved rods (50-100x0.3-0.4 microm) fell into the order of Methanomicrobiales, while the dominant organism ( approximately 98%), represented by straight rods with abrupt rectangular ends (3-9x0.5 microm), was affiliated with earlier uncultured 'Rice cluster I'. The main bacterial satellite used citrate as a single carbon and energy source; it was similar in both consortia, and after isolation in pure culture, it was identified as a new member of the alpha-subclass of Proteobacteria. The other bacterial satellites were distributed among four taxonomic groups: the delta-subclass of Proteobacteria, the Flavobacterium-Bacteroides-Cytophaga line of descent, the Acidobacterium-Fibrobacter line of descent and the Green non-sulfur bacteria line of descent. At least 11 out of 12 components of acido-tolerant consortia are new to science at the species, genus and order levels; their existence until now was evident only from environmental gene retrievals. The Sphagnum wetlands, attracting attention only recently because of their global environmental role, are shown to be an especially valuable source of novel prokaryotic organisms. PMID:19719599

  3. Assessing Metabolic Changes in Response to mTOR Inhibition in a Mantle Cell Lymphoma Xenograft Model Using AcidoCEST MRI

    PubMed Central

    Akhenblit, Paul J.; Hanke, Neale T.; Gill, Alexander; Persky, Daniel O.; Howison, Christine M.; Pagel, Mark D.; Baker, Amanda F.

    2016-01-01

    AcidoCEST magnetic resonance imaging (MRI) has previously been shown to measure tumor extracellular pH (pHe) with excellent accuracy and precision. This study investigated the ability of acidoCEST MRI to monitor changes in tumor pHe in response to therapy. To perform this study, we used the Granta 519 human mantle cell lymphoma cell line, which is an aggressive B-cell malignancy that demonstrates activation of the phosphatidylinositol-3-kinase/Akt/mammalian target of rapamycin (mTOR) pathway. We performed in vitro and in vivo studies using the Granta 519 cell line to investigate the efficacy and associated changes induced by the mTOR inhibitor, everolimus (RAD001). AcidoCEST MRI studies showed a statistically significant increase in tumor pHe of 0.10 pH unit within 1 day of initiating treatment, which foreshadowed a decrease in tumor growth of the Granta 519 xenograft model. AcidoCEST MRI then measured a decrease in tumor pHe 7 days after initiating treatment, which foreshadowed a return to normal tumor growth rate. Therefore, this study is a strong example that acidoCEST MRI can be used to measure tumor pHe that may serve as a marker for therapeutic efficacy of anticancer therapies. PMID:27140422

  4. Importance of indium tin oxide surface acido basicity for charge injection into organic materials based light emitting diodes

    NASA Astrophysics Data System (ADS)

    Nüesch, F.; Forsythe, E. W.; Le, Q. T.; Gao, Y.; Rothberg, L. J.

    2000-06-01

    The influence of the indium tin oxide (ITO) electrode surface acido basicity on organic electroluminescent device characteristics is studied. As measured by photoelectron spectroscopy, acid and base treatments produce large work function shifts of the oxide compared to standard ITO treated by an oxygen plasma or water. The current onsets for triphenyldiamine (TPD) single layer diodes sandwiched between ITO and a silver electrode are in qualitative agreement with the work function of the hole injecting oxide electrode. However, saturated photovoltage measurements on single layer diodes built on acid and water treated ITO disagree with the work function obtained from photoelectron experiments. This is explained by protonation of the diamine layer close to the electrode surface producing a charged double layer. It suggests that even acidic surface hydroxyl groups of the oxide electrode are able to protonate the diamine layer, explaining the importance of plasma cleaning to remove surface hydroxyls. The same ITO treatments are investigated in tris(8-hydroxyquinoline) (Alq) aluminum single layer diodes as well as hybrid TPD/Alq light emitting devices. Implications of metal-oxide surface acido basicity on electrode treatment and molecular material design are discussed.

  5. Respiration gating and Bloch fitting improve pH measurements with acidoCEST MRI in an ovarian orthotopic tumor model

    PubMed Central

    Jones, Kyle M; Randtke, Edward A; Howison, Christine M; Pagel, Mark D

    2016-01-01

    We have developed a MRI method that can measure extracellular pH in tumor tissues, known as acidoCEST MRI. This method relies on the detection of Chemical Exchange Saturation Transfer (CEST) of iopamidol, an FDA-approved CT contrast agent that has two CEST signals. A log10 ratio of the two CEST signals is linearly correlated with pH, but independent of agent concentration, endogenous T1 relaxation time, and B1 inhomogeneity. Therefore, detecting both CEST effects of iopamidol during in vivo studies can be used to accurately measure the extracellular pH in tumor tissues. Past in vivo studies using acidoCEST MRI have suffered from respiration artifacts in orthotopic and lung tumor models that have corrupted pH measurements. In addition, the non-linear fitting method used to analyze results is unreliable as it is subject to over-fitting especially with noisy CEST spectra. To improve the technique, we have recently developed a respiration gated CEST MRI pulse sequence that has greatly reduced motion artifacts, and we have included both a prescan and post scan to remove endogenous CEST effects. In addition, we fit the results by parameterizing the contrast of the exogenous agent with respect to pH via the Bloch equations modified for chemical exchange, which is less subject to over-fitting than the non-linear method. These advances in the acidoCEST MRI technique and analysis methods have made pH measurements more reliable, especially in areas of the body subject to respiratory motion. PMID:27212783

  6. Respiration gating and Bloch fitting improve pH measurements with acidoCEST MRI in an ovarian orthotopic tumor model

    NASA Astrophysics Data System (ADS)

    Jones, Kyle M.; Randtke, Edward A.; Howison, Christine M.; Pagel, Mark D.

    2016-03-01

    We have developed a MRI method that can measure extracellular pH in tumor tissues, known as acidoCEST MRI. This method relies on the detection of Chemical Exchange Saturation Transfer (CEST) of iopamidol, an FDA-approved CT contrast agent that has two CEST signals. A log10 ratio of the two CEST signals is linearly correlated with pH, but independent of agent concentration, endogenous T1 relaxation time, and B1 inhomogeneity. Therefore, detecting both CEST effects of iopamidol during in vivo studies can be used to accurately measure the extracellular pH in tumor tissues. Past in vivo studies using acidoCEST MRI have suffered from respiration artifacts in orthotopic and lung tumor models that have corrupted pH measurements. In addition, the non-linear fitting method used to analyze results is unreliable as it is subject to over-fitting especially with noisy CEST spectra. To improve the technique, we have recently developed a respiration gated CEST MRI pulse sequence that has greatly reduced motion artifacts, and we have included both a prescan and post scan to remove endogenous CEST effects. In addition, we fit the results by parameterizing the contrast of the exogenous agent with respect to pH via the Bloch equations modified for chemical exchange, which is less subject to over-fitting than the non-linear method. These advances in the acidoCEST MRI technique and analysis methods have made pH measurements more reliable, especially in areas of the body subject to respiratory motion.

  7. An acido-triggered reversible luminescent and nonlinear optical switch based on a substituted styrylpyridine: EFISH measurements as an unusual method to reveal a protonation-deprotonation NLO contrast.

    PubMed

    Cariati, Elena; Dragonetti, Claudia; Lucenti, Elena; Nisic, Filippo; Righetto, Stefania; Roberto, Dominique; Tordin, Elisa

    2014-02-14

    Diphenyl-(4-{2-[4-(2-pyridin-4-yl-vinyl)-phenyl]-vinyl}-phenyl)-amine (DPVPA) constitutes a novel acido-triggered reversible luminescent and nonlinear optical switch. Remarkably, for the first time the Electric-Field Induced Second Harmonic generation (EFISH) technique is used to reveal a protonation-deprotonation NLO contrast.

  8. Acido-basic control of the thermoelectric properties of poly(3,4-ethylenedioxythiophene)tosylate (PEDOT-Tos) thin films

    PubMed Central

    Khan, Zia Ullah; Bubnova, Olga; Jafari, Mohammad Javad; Brooke, Robert; Liu, Xianjie; Gabrielsson, Roger; Ederth, Thomas; Evans, Drew R.; Andreasen, Jens W.; Fahlman, Mats

    2015-01-01

    PEDOT-Tos is one of the conducting polymers that displays the most promising thermoelectric properties. Until now, it has been utterly difficult to control all the synthesis parameters and the morphology governing the thermoelectric properties. To improve our understanding of this material, we study the variation in the thermoelectric properties by a simple acido-basic treatment. The emphasis of this study is to elucidate the chemical changes induced by acid (HCl) or base (NaOH) treatment in PEDOT-Tos thin films using various spectroscopic and structural techniques. We could identify changes in the nanoscale morphology due to anion exchange between tosylate and Cl– or OH–. But, we identified that changing the pH leads to a tuning of the oxidation level of the polymer, which can explain the changes in thermoelectric properties. Hence, a simple acid–base treatment allows finding the optimum for the power factor in PEDOT-Tos thin films. PMID:27019715

  9. Utility of charge-transfer complexation for the assessment of macrocyclic polyethers: Spectroscopic, thermal and surface morphology characteristics of two highly crown ethers complexed with acido acceptors

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; Adam, Abdel Majid A.; Saad, Hosam A.

    2015-04-01

    The study of the complexing ability of macrocyclic compounds to organic and inorganic substances is of great interest. The aim of this work is to provide basic data that can be used to the assessment of macrocyclic crown ethers quantitatively based on charge-transfer (CT) complexation. This goal was achieved by preparing CT complexes of two interesting mixed nitrogen-oxygen crown ethers with acido acceptors (chloranilic and picric acid), which were fully structurally characterized. The crown ethers are 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane (HDHC) and 1,4,10-trioxa-7,13-diaza-cyclopentadecane (TDPD). The obtained complexes were structurally characterized via elemental analysis, IR, Raman, 1H NMR, and UV-visible spectroscopy. Thermal properties of these complexes were also studied, and their kinetic thermodynamic parameters were calculated. Furthermore, the microstructure properties of these complexes have also been investigated using X-ray diffraction (XRD) and scanning electron microscope (SEM).

  10. Acido-base behavior of hydroxamic acids: experimental and ab initio studies on hydroxyureas.

    PubMed

    Vrcek, Ivana Vinković; Kos, Ivan; Weitner, Tin; Birus, Mladen

    2008-11-20

    The values of Ka, DeltaSa, and DeltaHa for deprotonation of hydroxyurea (HU) and N-methylhydroxyurea (NMHU), as targeted compounds, and for betainohydroxamic acid, were potentiometrically determined. Although NMHU has two and HU even three deprotonation sites, the measurements confirm that they behave as weak acids with a single pK a approximately 10. Comparison with analogous thermodynamic parameters previously determined for series of monohydroxamic acids reveals deviations from a DeltaSa, vs DeltaHa plot for HU and NMHU, raising the question of the dissociation site of hydroxureas in water. In addition to the deprotonation of the hydroxyl oxygen, ab initio calculations performed at the MP2/6-311++G(d,p) level of theory for these two compounds indicate a notable participation of the nitrogen deprotonation site in HU. The calculations for the isolated, monohydrate, trihydrate, and decahydrate molecular and anionic forms of hydroxyureas support the importance of hydrogen bonding in the gas and aqueous phases. The hydroxylamino nitrogen in HU is the most acidic site in water, contributing approximately 94% to the overall deprotonation process at 25 degrees C. On the contrary, the hydroxylamino oxygen is by far the most favored deprotonation site in NMHU, contributing almost 100% in aqueous medium. The predicted participations of two deprotonation sites in HU, calculated at the MP2/6-311++G(d,p) level of theory, combined with the calculated relative reaction enthalpy and entropy for the deprotonation, satisfactorily explain the observed deviation from linearity of DeltaHa vs DeltaSa, plot. There is no such a simple explanation for acid-base behavior of NMHU.

  11. Acido, ergo sum: Holger Hydén--the neuroscientist in Cortázar's Hopscotch.

    PubMed

    Delgado, Guillermo; Estañol, Bruno

    2013-06-01

    The fictional Italian author Morelli is throughout the novel "Hopscotch" (1963) Julio Cortázar's alter ego. This character proposes an unoriginal literary hypothesis in chapter 62. There is an allusion to a particular Swedish that 'is working on a chemical theory of thought.' The Swedish neuroscientist under analysis is Holger Hydén (1917-2000), by then professor and chairman of the Department of Histology at the University of Göteborg. Hydén, who was the first to work in neurobiological micromethods, is mentioned by Morelli due to his participation in a symposium held at the end of January 1961, in San Francisco. His pioneering work will never be completely forgotten, because Hydén's neuroscientific legacy lives and will live in Cortázar's "Hopscotch".

  12. Acido, ergo sum: Holger Hydén--the neuroscientist in Cortázar's Hopscotch.

    PubMed

    Delgado, Guillermo; Estañol, Bruno

    2013-06-01

    The fictional Italian author Morelli is throughout the novel "Hopscotch" (1963) Julio Cortázar's alter ego. This character proposes an unoriginal literary hypothesis in chapter 62. There is an allusion to a particular Swedish that 'is working on a chemical theory of thought.' The Swedish neuroscientist under analysis is Holger Hydén (1917-2000), by then professor and chairman of the Department of Histology at the University of Göteborg. Hydén, who was the first to work in neurobiological micromethods, is mentioned by Morelli due to his participation in a symposium held at the end of January 1961, in San Francisco. His pioneering work will never be completely forgotten, because Hydén's neuroscientific legacy lives and will live in Cortázar's "Hopscotch". PMID:23828537

  13. Acid—base behavior of aluminum and silicon oxides — a combination of two approaches: XPS and Lewis acido-basicity; rest potential and Brönsted acido-basicity

    NASA Astrophysics Data System (ADS)

    Casamassima, M.; Darque-Ceretti, E.; Etcheberry, A.; Aucouturier, M.

    1991-11-01

    In the frame of an investigation on adhesion phenomena between elastomers and oxide substrates, X-ray photoelectron spectroscopy (XPS) and rest electrochemical potential measurements have been used in order to attempt a characterization of the reactivity of various oxides. The first step of the study is a definition of donor/acceptor properties for a solid surface in an interactive model such as the Lewis one. In this case, the Fermi level is an appropriate parameter. An experimental approach is developed to estimate this parameter through photoelectronical data obtained by XPS. As proposed by Mullins and Averbach in 1988 in the case of Al and Si oxides, XPS allows an estimation of the Fermi energy EF, defined as the energy difference between the Fermi level and the upper occupied valence band. A classification of EF values is obtained for different samples of aluminum and silicon oxides; the donor (acceptor) behavior increases for decreasing (increasing) EF. The second step is the validation of the EF classification obtained by XPS. A potentiometric method is used to estimate the rest potential Eo in aqueous solution. The relationship between the Eo and the solution pH is a Nernst law for a large range of pH values, which means that the system is governed by acid-base interactions in Brönsted definition in the interfacial area. When the nature of the oxide substrate is modified, the translation of the Eo versus pH line can be correlated with the EF classification obtained previously. This confirms the relationship already reported between point of zero charge and EF. It can also be considered as a validation of the idea that XPS allows the classification of EF values for those oxides.

  14. Effects of acido-basic support properties on the catalytic hydrogenation of acetylene on gold nano-particles

    NASA Astrophysics Data System (ADS)

    Manda, Abdullah Ahmed

    Metallic gold nanoparticles supported on gamma-Al2O 3 and magnesia-alumina mixed oxide, with different magnesia content have been prepared by sol-gel method and characterized by different techniques (inductive coupled plasma-mass spectroscopy (ICP-MS), XRD, BET surface area analysis, transmission electron microscopy (TEM), CO2 and NH 3 temperature programmed desorption (TPD), H2 temperature programmed reduction (TPR) and FTIR of adsorbed CO2). Such systems were found to produce catalysts with controllable acidity, varying from catalyst possessing large density of acidic and low density of basic sites, others with acidic and basic sites of equal strength and density, and others with large basic and low acid sites densities, respectively. The catalytic assessment of the generated acidity was carried out using 2-propanol decomposition as a test reaction. The results obtained indicate that the presence of magnesia and reduced gold nanopartilces has imparted the catalysts, 1%Au/4%Mg-Al 2O3 and 1%Au/8%Mg-Al2O3, with significant base-catalytic properties. Acetylene hydrogenation and formation of coke deposits were investigated on a gold catalyst supported on gamma-Al2O3 and gold supported on alumina-magnisia mixed oxide with different gold content; 1%Au/gamma-Al 2O3, 1%Au/15%Mg-Al2O3, 2%Au/15%Mg-Al 2O3 and 4%Au/15%Mg-Al2O3. The effect of the H2/C2H2 ratio was studied over a range of values. The catalytic activity and selectivity towards ethylene and other products were investigated at different reaction temperatures. Acetylene hydrogenation was investigated in the presence and absence of ethylene in stream. It is investigated that the adsorption of the triple bond is preferred over the double bond and during selective catalytic (SCR) of C2H2 the two hydrocarbons do not compete for the same adsorption sites. The deactivation of catalysts was studied by temperature programmed oxidation (TPO). Higher content of coke over 1%Au/Al2O3 catalyst was investigated in contrast to the other catalysts in which the basisity of magnesia-alumina supports could have played an important role in inhibiting the acidic carbon formation by possessing smaller number and/or weaker acid sites.

  15. Effectiveness of anisodamine for the treatment of critically ill patients with septic shock (ACIdoSIS study): study protocol for randomized controlled trial

    PubMed Central

    Zhou, Jiancang; Shang, You; Wang, Xin’an; Yin, Rui; Zhu, Zhenhua; Chen, Wensen; Tian, Xin; Yu, Yuetian; Zuo, Xiangrong; Chen, Kun; Ji, Xuqing; Ni, Hongying

    2015-01-01

    Background Septic shock is an important contributor of mortality in the intensive care unit (ICU). Although strenuous effort has been made to improve its outcome, the mortality rate is only marginally decreased. The present study aimed to investigate the effectiveness of anisodamine in the treatment of septic shock, in the hope that the drug will provide alternatives to the treatment of septic shock. Methods The study is a multi-center randomized controlled clinical trial. Study population will include critically ill patients with septic shock requiring vasopressor use. Blocked randomization was performed where anisodamine and control treatments were allocated at random in a ratio of 1:1 in blocks of sizes 2, 4, 6, 8, and 10 to 354 subjects. Interim analysis will be performed. The primary study end point is the hospital mortality, and other secondary study endpoints include ICU mortality, length of stay in ICU and hospital, organ failure free days. Adverse events including new onset psychosis, urinary retention, significant hypotension and tachycardia will be reported. Discussion The study will provide new insight into the treatment of septic shock and can help to reduce mortality rate of septic shock. Trial registration NCT02442440 (https://register.clinicaltrials.gov/). PMID:26605292

  16. Band profiles of reacting acido-basic compounds with water-methanol eluents at different SWpHs and ionic strengths in reversed-phase liquid chromatography.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2009-04-10

    Overloaded band profiles of aniline (25 microL injection of a 30.5mM solution) eluted with a methanol-aqueous buffer solution (30/70, v/v) were recorded at the exit of a 150 mm x 4.6mm column packed with 3.5 microm XBridge-C(18)porous particles. The SWpHs of the mobile phase was adjusted with phosphate (SWpHs approximately 2.7 and SWpHs approximately 7.5) or acetate buffers (SWpHs approximately 5.3) of different concentrations (11, 56, and 278 mM). The elution times and profiles of the bands observed at low ionic strength were successfully accounted for using the extended Debye-Hückel theory to estimate the activity coefficients of the ions in the bulk phase and a simple non-competitive Langmuir adsorption model, the adsorption of pure aniline or pure anilinium onto XBridge-C(18) being described by a Langmuir isotherm. The band profiles were calculated using this adsorption model and the equilibrium-dispersive model of chromatography. The calculated and the experimental band profiles are in excellent agreement at all buffer pH and ionic strength. This demonstrates that the elution times and the band profiles are controlled by the chromatographic dilution process and by the reaction of aniline with the buffer solution.

  17. [Values of acido-basic balance in the blood of the beagle breed dog in comparison with the German shepherd dog].

    PubMed

    Komárek, J; Jadrný, L; Sýkora, I

    1975-01-01

    The values of acidobasic balance were examined in 101 dogs of the Beagle breed and in 20 German Sheep-Dogs. The Beagle dogs were divided into five age groups. A difference was found between the values obtained in the group of the youngest dogs and those in older age groups. In comparison with Beagle dogs, the values were higher in German Sheep-Dogs (pH, base excess). A figure is attached representing the deviations of the values of acidobasic balance of blood in the two breeds.

  18. Crystal Structure of ATVORF273, a New Fold for a Thermo- and Acido-Stable Protein from the Acidianus Two-Tailed Virus

    PubMed Central

    Felisberto-Rodrigues, Catarina; Blangy, Stéphanie; Goulet, Adeline; Vestergaard, Gisle; Cambillau, Christian; Garrett, Roger A.; Ortiz-Lombardía, Miguel

    2012-01-01

    Acidianus two-tailed virus (ATV) infects crenarchaea of the genus Acidianus living in terrestrial thermal springs at extremely high temperatures and low pH. ATV is a member of the Bicaudaviridae virus family and undergoes extra-cellular development of two tails, a process that is unique in the viral world. To understand this intriguing phenomenon, we have undertaken structural studies of ATV virion proteins and here we present the crystal structure of one of these proteins, ATV. ATV forms tetramers in solution and a molecular envelope is provided for the tetramer, computed from small-angle X-ray scattering (SAXS) data. The crystal structure has properties typical of hyperthermostable proteins, including a relatively high number of salt bridges. However, the protein also exhibits flexible loops and surface pockets. Remarkably, ATV displays a new protein fold, consistent with the absence of homologues of this protein in public sequence databases. PMID:23056221

  19. Archaebakterien und Phylogenie der Organismen

    NASA Astrophysics Data System (ADS)

    Kandler, Otto

    1981-04-01

    The determination of the sequence similarity of the ribosomal 16 S RNA of many bacteria and a few higher organisms has shown that the methanogenic, halophilic, and acido-thermophilic organisms are phylogenetically separated from the kingdoms of the Eubacteria and Eukaryotes thus representing a third kingdom called “Archaebacteria”. Many biochemical and molecular biological features support this conclusion.

  20. Inhibition of fructan-fermenting equine fecal bacteria and Streptococcus bovis by hops (Humulus lupulus L.) ß-acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The goals were to determine if the '-acid from hops (Humulus lupulus L.) could be used to control fructan fermentation by equine hindgut microorganisms, and to verify the antimicrobial mode of action on the Streptococcus bovis, which has been implicated in fructan fermentation, hindgut acidos...

  1. [Ergometric results of r-erythropoietin treatment of hemodialysis patients].

    PubMed

    Hortian, B; Schmidt, R; Wüstenberg, P W; Dörp, E; Schumann, L; Winkler, R; Klinkmann, H

    1990-05-15

    To investigate the effect of partial correction of anemia in patients maintained by chronic intermittent hemodialysis on exercise capacity, patients underwent a bicycle acido-ergometry before and after treatment with recombinant human erythropoietin. The results demonstrate a (subjective) improvement of exercise capacity without any evidence for that in the pH values.

  2. [Archaebacteria and phylogeny of organisms].

    PubMed

    Kandler, O

    1981-04-01

    The determination of the sequence similarity of the ribosomal 16S RNA of many bacteria and a few higher organisms has shown that the methanogenic, halophilic, and acido-thermophilic organisms are phylogenetically separated from the kingdoms of the Eubacteria and Eukaryotes thus representing a third kingdom called "Archaebacteria". Many biochemical and molecular biological features support this conclusion.

  3. [CONSUMPTION OF OMEGA- 3 FATTY ACIDS AND DEPRESSIVE SYMPTOMS IN COLLEGE STUDENTS FROM SONORA, MEXICO].

    PubMed

    Rubi Vargas, María; González Lomelí, Daniel; Terrazas Medina, Efraín A; Peralta Peña, Sandra L; Jordán Jinez, Ma Lourdes; Ruiz Paloalto, Ma Laura; Cupul Uicab, Lea A

    2015-10-01

    Introducción: estudios recientes sugieren que los niveles bajos de acidos grasos poliinsaturados omega-3 se relacionan con una mayor prevalencia de depresion; sin embargo, los resultados no son concluyentes. Objetivo: evaluar la asociacion entre el bajo consumo de acidos grasos omega-3 y la presencia de sintomas depresivos en jovenes universitarios del noroeste de Mexico. Métodos: se realizo un estudio transversal en una muestra de 706 universitarios de 18 a 24 anos de edad de ambos sexos. La presencia de sintomatologia depresiva se estimo con la escala de Depresion del Centro de Estudios Epidemiologicos (CES-D) empleando un punto de corte ≥ 24. El consumo semanal de acidos grasos alfalinolenico (ALA) y de eicosapentaenoico (EPA) mas docosahexaenoico (DHA) en mg/g de alimento se estimo por medio de un cuestionario de frecuencia de consumo de alimentos validado para la poblacion mexicana. La asociacion del consumo de omega-3 con la presencia de sintomas depresivos se evaluo con modelos de regresion logistica. Resultados: el 67% de los participantes fueron mujeres; en general, el 16,6% presentaron sintomatologia depresiva. El consumo bajo de ALA y EPA + DHA no se asocio con mayor prevalencia de sintomatologia depresiva antes y despues de ajustar por confusores. En aquellos casos con sintomatologia depresiva, los niveles ALA derivados solo de las nueces fueron significativamente menores. Conclusiones: en esta poblacion no se observo asociacion entre el bajo consumo de acidos grasos omega-3 y la sintomatologia depresiva. La posible asociacion entre el consumo de nueces y la sintomatologia depresiva requiere de mas estudios.

  4. Effect of monofluoroacetate on renal H+ excretion in the rat.

    PubMed

    Simonnet, H; Gauthier, C; Pellet, M V

    1979-05-01

    In order to investigate the effect of monofluoroacetate (MFA) on renal H+ excretion, anesthetized rats under mannitol diuresis were given intraperitoneally MFA and some of the acido-basic status parameters were determined. Urinary pH and pCO2 did not change after MFA administration, while urinary flow rate increased. MFA induced a decrease in H+ net excretion and in ammonia excretion. Titratable acidity did not change significantly within the experiment.

  5. [Hypomyelination with atrophy of the basal ganglia and cerebellum. Contribution of two new cases to a recently reported entity].

    PubMed

    Tomás-Vila, Miguel; Menor, Francisco; Ley-Martos, Myriam; Jumillas-Luján, M José; Marco-Hernández, Ana V; Barbero, Pedro

    2014-02-16

    Introduccion. La hipomielinizacion con atrofia de ganglios basales y de cerebelo (H-ABC) es una rara entidad descrita recientemente. Se presentan dos nuevos casos pertenecientes a una misma familia. Casos clinicos. Caso 1: niño de 17 meses con retraso grave en todas las areas, ausencia de lenguaje y de contacto visual. En la exploracion destacaba una microcefalia con tetraparesia espastica. En la resonancia magnetica cerebral se apreciaba atrofia cerebelosa de predominio vermiano con perdida de volumen de ambos nucleos del putamen y la cabeza del caudado, y patron de hipomielinizacion de la sustancia blanca. En la electromiografia se objetivo un patron de polineuropatia cronica de predominio motor. Presento un descenso de los valores de acido homovalinico y de acido 5-hidroxindolacetico. El tratamiento con levodopa/carbidopa no fue efectivo. Caso 2: niña de 11 meses, hermana del caso anterior. Presentaba un retraso grave en todas las areas y en la exploracion clinica se detecto una microcefalia con tetraparesia espastica. La resonancia magnetica cerebral mostro hallazgos superponibles a los del hermano, con hipomielinizacion, atrofia cerebelosa y afectacion putaminal y de ambos caudados; en la electromiografia, hallazgos compatibles con polineuropatia motora de caracter desmielinizante. Presento un descenso de los valores de acido homovalinico y acido 5-hidroxindolacetico en el liquido cefalorraquideo. El tratamiento con levodopa/carbidopa resulto ineficaz. Conclusiones. Estos dos nuevos casos ayudan a caracterizar mejor esta entidad y refuerzan la hipotesis del origen genetico del sindrome, dado que se trata de dos casos pertenecientes a una misma familia.

  6. Chloroperoxidase-catalyzed enantioselective oxidation of methyl phenyl sulfide with dihydroxyfumaric acid/oxygen or ascorbic acid/oxygen as oxidants.

    PubMed

    Pasta; Carrea; Monzani; Gaggero; Colonna

    1999-02-01

    The chloroperoxidase catalyzed oxidation of methyl phenyl sulfide to (R)-methyl phenyl sulfoxide was investigated, both in batch and membrane reactors, using as oxidant H2O2, or O2 in the presence of either dihydroxyfumaric acid or ascorbic acid. The effects of pH and nature and concentration of the oxidants on the selectivity, stability, and productivity of the enzyme were evaluated. The highest selectivity was displayed by ascorbic acid/O2, even though the activity of chloroperoxidase with this system was lower than that obtained with the others. When the reaction was carried out in a membrane reactor, it was possible to reuse the enzyme for several conversion cycles. The results obtained with ascorbic acid/O2 and dihydroxyfumaric acid/O2 as oxidants do not seem to be compatible with either a mechanism involving hydroxyl radicals as the active species or with the hypothesis that oxidation occurs through the initial formation of H2O2. Copyright 1999 John Wiley & Sons, Inc.

  7. [Use of fish oil lipid emulsions in hospitalized patients under 18 years old with abnormal results in liver tests associated with total parental nutrition].

    PubMed

    Giraldo Villa, Adriana; Henao Roldan, Catherine; García Loboguerrero, Fanny; Martínez Volkmar, María Isabel; Contreras Ramírez, Mónica María; Ruiz Navas, Patricia

    2014-04-01

    Introducción: La Nutricion Parental Total (NPT) prolongada esta asociada con complicaciones potencialmente mortales en la poblacion pediatrica como lo es la colestasis. Dentro del soporte nutricional, la fuente de acidos grasos, el contenido de fitoesteroles y la dosis de lipidos se han relacionado con el desarrollo de esta complicacion. Objetivo: Describir el comportamiento de las pruebas hepaticas en pacientes pediatricos con NPT en quienes se uso lipidos a base de acidos grasos omega 3 (omegavenR). Métodos: Estudio retrospectivo, en menores de 18 anos con tratamiento intravenoso por minimo 8 dias con acidos grasos omega 3. Los pacientes fueron inicialmente clasificados en dos grupos: colestasis y alteracion de pruebas hepaticas. Se evaluo el comportamiento de la transaminasa glutamico oxalacetica (TGO), transaminasa glutamico piruvica (TGP), bilirrubina total (BT), bilirrubina directa, gama glutamil transferasa (GGT) y fosfatasa alcalina (FA) antes y despues del tratamiento con omegaven R. Resultados: 33 pacientes cumplieron los criterios de inclusion. Al finalizar la administracion de omegavenR, 82,4% de los pacientes que presentaron inicialmente colestasis mostraron resolucion o mejoria. En el grupo de pacientes con alteracion de pruebas hepaticas 18,8% progresaron a colestasis. Conclusiones: Nuestro estudio sugiere que el uso de omegaven R en pacientes pediatricos con NPT y BD ≥ 2 mg/dL, parece revertir o mejorar la colestasis, mientras que en pacientes con alteracion de pruebas hepaticas aun no se tiene claro su efecto.

  8. [Birth asphyxia as a cause of cerebral palsy].

    PubMed

    Hadzagić-Catibusić, F; Heljić, S; Buljina, A

    2000-01-01

    Birth asphyxia is O2i CO2 exchange disorder during the labour, with consequent hypoxia and ischemia. The term "asphyxia" has been used unprecisely quite often. The most frequently used criteria for birth asphyxia have been: fetal bradycardia, meconium stained amniotic fluid, fetal acido-base status with umbilical artery pH value below 7.10, low Apgar score and need for endotracheal intubation. The correct Apgar score quantification depends on the examiner. Fetal acido-base status measured in umbilical artery could be useful biochemical parameter of birth asphyxia. Only if the fetal oxygen supply during the labour is severe and long enough disturbed, the neurological abnormalities will develop later. Our study has enrolled 70 children with various degree of motor impairment, detected during neonatal period and/or infancy. They have been followed up till 24 months chronological age for term neonates and 24 months corrected age for prematures. 34 children out of them have developed clear clinical signs of cerebral palsy. Birth asphyxia as a possible cause of cerebral palsy has been documented in 10 cases, e.g. 29.4%. The criteria for birth asphyxia have been low Apgar score, meconium stained amniotic fluid and clinical signs of hypoxic-ischemic encephalopathy. Fetal blood gas and acido-base measurements obtained from umbilical artery at delivery have been an important parameter of intrapartal asphyxia. Those measurements should be introduced as a routine method in our practice, in the cases of fetal heart deceleration, to asses the extent of fetal acidosis.

  9. [Status epilepticus in paediatrics: a retrospective study and review of the literature].

    PubMed

    Moreno-Medinilla, Esther E; Negrillo-Ruano, Rocío; Calvo-Medina, Rocío; Mora-Ramírez, M Dolores; Martínez-Antón, Jacinto L

    2015-05-01

    Introduccion. El estado epileptico (EE) es la emergencia neurologica mas frecuente en pediatria. Dada la posibilidad de secuelas neurologicas y mortalidad asociadas, requiere un tratamiento agresivo precoz. Pacientes y metodos. Estudio descriptivo retrospectivo a traves de la revision de historias clinicas de pacientes ingresados en nuestro hospital entre 2010-2013 con diagnostico de EE. El objetivo fue describir las caracteristicas epidemiologicas y el manejo de estos pacientes, asi como revisar la bibliografia disponible sobre este tema. Resultados. Hemos recogido 39 pacientes (25 varones) y 51 episodios de EE. Edad media: 4,8 años. Tenian enfermedad de base 22 pacientes. Dieciocho eran epilepticos conocidos y cinco tuvieron un EE previo. De los 51 episodios de EE, 33 fueron sintomaticos, 15 febriles y tres criptogenicos. Los tipos de EE fueron: 25 parciales (de ellos, 16 complejos) y 26 generalizados. El tratamiento de primera eleccion fue benzodiacepinas en 47 pacientes (40, diacepam), fenitoina en tres y acido valproico en uno. Veintisiete pacientes precisaron farmacos de segunda linea: 16, acido valproico; ocho, fenitoina; dos, fenobarbital; y uno, levetiracetam. Diez pacientes precisaron farmacos de tercera linea para la induccion del coma: el midazolam fue el mas utilizado en nuestro centro, seguido del tiopental y el propofol. Dos EE superrefractarios requirieron inmunoglobulinas y corticoides sistemicos por presentarse en el curso de encefalitis autoinmunes. Conclusiones. Debe plantearse el esquema terapeutico del EE desde el inicio de cualquier crisis convulsiva. El tratamiento es escalonado, con benzodiacepinas en la primera etapa, antiepilepticos de amplio espectro y disponibilidad intravenosa en la segunda (acido valproico, levetiracetam en el EE generalizado y fenitoina en el EE focal), mientras que el tercer nivel varia en funcion de la experiencia de cada equipo.

  10. Comparative Studies on Biochemical Properties of Protein Synthesis of an Archae-Bacteria Thermoplasma-Sp

    NASA Astrophysics Data System (ADS)

    Ohba, Masayuki; Oshima, Tairo

    1982-12-01

    An acido-thermophillic archaebacteria,Thermoplasma strain KO-2, produced poly(A) containing RNA. The isolated poly(A)RNA showed the messenger activity in a cell-free extract of rabbit reticulocyte, indicating that the RNA is mRNA of the archaebacteria. 7-Methylgluanosine 5'-phosphate did not inhibit the reaction, suggesting that the cap structure is not present in the messenger. These results may suggest that poly(A) containing messenger arised at very early stage of evolution prior to the divergence between archaebacteria and eukaryotes.

  11. Protometric thermometric titrations of sparingly soluble compounds in water in the presence of n-octanol.

    PubMed

    Burgot, G; Burgot, J-L

    2002-10-15

    Thermometric titrimetry permits titration of acido-basic compounds in water in the presence of n-octanol. n-Octanol permits the solubilization of protolytes and moreover may also displace the equilibria of the titration reactions. Hydrochlorides of highly insoluble derivatives such as phenothiazine derivatives can be titrated with satisfactory accuracy and precision by sodium hydroxide despite their high pK(a) values. Likewise barbiturate salts can be titrated by hydrochloric acid. In the case of some salts, the methodology may permit the sequential titration of the ion and counter ion.

  12. Diabetic ketoacidosis in children.

    PubMed

    Reitano, G

    1989-01-01

    Ketoacidosis is a metabolic alteration caused by absolute or relative insulin deficiency and oversecretion of glucagon. Prompt diagnosis and rapid initiation of treatment are mandatory to avoid the complications and fatal outcome. Reduction of plasma glucose to levels within acceptable limits, block of ketogenesis, re-establishment of hydroelectrolytic balance, correction of alterations of acido-base status are the most important goals in DKA treatment. However, all the corrections should be made slowly and under continuous control. Altered parameters must slope off very gradually to prevent dangerous hazards.

  13. [Aetiology and treatment of epilepsy in a series of 1,557 patients].

    PubMed

    Torres-Ferrús, Marta; Toledo, Manuel; González-Cuevas, Montserrat; Seró-Ballesteros, Laia; Santamarina, Esteban; Raspall-Chaure, Miquel; Sueiras-Gil, María; Cambrodí-Masip, Roser; Sarria, Silvana; Álvarez-Sabín, José; Salas-Puig, Javier

    2013-10-01

    Introduccion. La etiologia de la epilepsia es un determinante importante del tratamiento y el pronostico. Los avances diagnosticos y terapeuticos hacen pensar que la distribucion causal, el tratamiento y el pronostico de la poblacion con epilepsia se hayan podido ver modificados. Objetivo. Describir la distribucion sindromica, etiologica y el tratamiento farmacologico en los pacientes con epilepsia. Pacientes y metodos. Estudio descriptivo transversal de pacientes con epilepsia atendidos de manera consecutiva en la consulta de nuestra unidad de epilepsia. Se recogieron datos demograficos, de sindrome, etiologia y tratamiento farmacologico en el momento de la inclusion. Se analizaron los datos de modo conjunto y por grupos de edad. Resultados. Se incluyeron 1.557 pacientes, el 54% varones. El 73% de la muestra tenia una epilepsia focal, que era secundaria a una lesion estructural en el 56%. Las epilepsias generalizadas representaron el 20%. El 5% fue inclasificable. Por edad, la etiologia vascular predominaba en practicamente todos los grupos y su prevalencia aumentaba en relacion con la edad. Los farmacos antiepilepticos mas utilizados fueron acido valproico (29%), levetiracetam (27%) y carbamacepina (20%). El 70% de las epilepsias generalizadas y el 57% de las focales seguian tratamiento en monoterapia. Conclusiones. La prevalencia por grupos de edad fue similar a la descrita en paises desarrollados aunque se observo una menor prevalencia de epilepsias criptogenicas. Mas del 60% de los pacientes seguia monoterapia y el acido valproico fue el mas utilizado.

  14. First principle study of the surface reactivity of layered lithium oxides LiMO2 (M = Ni, Mn, Co)

    NASA Astrophysics Data System (ADS)

    Vallverdu, Germain; Minvielle, Marie; Andreu, Nathalie; Gonbeau, Danielle; Baraille, Isabelle

    2016-07-01

    LiNixMnyCo1 - x - yO2 compounds (NMC) are layered oxides widely used in commercial lithium-ion batteries at the positive electrode. Nevertheless surface reactivity of this material is still not well known. As a first step, based on first principle calculations, this study deals with the electronic properties and the surface reactivity of LiMO2 (M = Co, Ni, Mn) compounds, considering the behavior of each transition metal separately in the same R 3 ̅ mα-NaFeO2-type structure, the one of LiCoO2 and NMC. For each compound, after a brief description of the bare slab electronic properties, we explored the acido-basic and redox properties of the (110) and (104) surfaces by considering the adsorption of a gaseous probe. The chemisorption of SO2 produces both sulfite or sulfate species associated respectively to an acido-basic or a reduction process. These processes are localized on the transition metals of the first two layers of the surface. Although sulfate species are globally favored, a different behavior is obtained depending on both the surface and the transition metal considered. We conclude with a simple scheme which describes the reduction processes on the both surfaces in terms of formal oxidation degrees of transition metals.

  15. Dichromated photosensitive materials: involvement of the polymeric matrix

    NASA Astrophysics Data System (ADS)

    Bolte, Michele; Israeli, Yael; Rivaton, Agnes; Frezet, Lawrence; Lessard, Roger A.

    2004-06-01

    Irradiation of dichromated polyvinyl alcohol and dichromated polyacrylic acid DC(PVA-PAA) at 365 nm was investigated in order to understand the involvement of the polymeric matrix in the reduction process of the Cr(VI) leading to the formation of the hologram. The photochemical evolution of the matrix was directly correlated to the disappearance of the absorbing species, chromium(VI). A special attention was paid to the absorption profile of the films. Due to the impermeability of the polymer, no oxidation proceeded. The reduction of Cr(VI) into Cr(V) induced the formation of carboxylate species perfectly correlated with the consumption of carboxylic groups. Besides the acido-basic reaction undergone by the carboxylic groups, the reduction of Cr(VI) provoked the cross-linking of the polymer. Each polymer appears to play a specific role in the mechanism.

  16. A photoelectron spectroscopy study on the indium tin oxide treatment by acids and bases

    NASA Astrophysics Data System (ADS)

    Nüesch, F.; Rothberg, L. J.; Forsythe, E. W.; Le, Quoc Toan; Gao, Yongli

    1999-02-01

    We report on the chemical adsorption of acids and bases on indium tin oxide (ITO). Ultraviolet photoelectron spectroscopy was used to measure the work function of the treated ITO and atomic surface concentrations were determined by x-ray photoelectron spectroscopy. The acid treatments yield work-function shifts as high as 0.7 eV compared to the nontreated ITO. Huge shifts in the work function are also obtained for the treatments with bases and are opposite to those obtained with the acids. These dramatic shifts are indicative of a double ionic surface layer. The importance of an appropriate plasma treatment prior to the chemical adsorption of acids or bases is discussed in terms of surface acido-basicity.

  17. The nucleotide sequence of the mouse embryonic beta-like y-globin messenger RNA as determined from cloned cDNA.

    PubMed

    Vanin, E F; Farace, M G; Gambari, R; Fantoni, A

    1981-12-01

    We have determined the nucleotide sequence of two cloned cDNAs corresponding to the mRNA of mouse embryonic y2 globin. The combined overlapping sequences span a total of 480 bp, beginning at the codon corresponding to amino acido residue 21 and extending to the AATAAA sequence in the 3' untranslated region. Therefore, when the amino acid sequence encoded by the cDNA is combined with the available amino acid sequence, a complete y2 protein sequence can be obtained. Comparisons, at the nucleotide level, between the known beta- and beta-like globin sequences and the y2 sequence show that the embryonic, fetal-adult duplication occurred approx. 160 million years (MY) ago and that the embryonic-fetal duplication occurred approx. 100 MY ago.

  18. Thermal stability of uranyl complexes with neutral oxygen-containing organic bases

    SciTech Connect

    Kobets, L.V.

    1987-03-01

    The thermal stability of uranyl chloride, nitrate, and oxalate with a series of neutral oxygen-containing organic ligands is discussed. It was found that the temperatures of removal of chlorine are higher than the stripping of the first molecule of the base in complexes UO/sub 2/Cl/sub 2/ x 2L. This is an indication of greater strength of the bonds of the Cl/sup -/ ions to the uranyl group in comparison with the investigated bases. It was shown that the temperatures of removal of a mole of neutral ligands depend little on the nature of the anions and exhibit a correlation with the donor capacity of the bases: Ac < TBP < DMFA similarly ordered DMSO < TBPO similarly ordered PyO. The chemistry of the decomposition of the complexes and the strength of the binding of the acido- and neutral ligands in them are discussed.

  19. [Biochemical complications of experimental vesico-sigmoidostomy].

    PubMed

    Nuñez, R; Blesa, E; Ramos, S; Morillo, M; Ortega, L; Requena, F; Cardesa, J J

    1987-03-01

    Three experimental models of vesico-sigmoidostomy are studied (model-1, end to side V-S plus urethral ligation, model-2, end to end V-S, in "Y of Rous" plus urethral ligation and model-3, vesico-sigmoidoplasty), with aim of reproducing chemical imbalance observed in human subjects with ureterosigmoidostomy. Authors have evaluated clinical biochemical (serum acido-base balance, Cl, Na+, K+, BUN, creatinine, ammonia and albumin), and histologic variables in the first, third and fifth month after operation in 225 rats. Animal of model-1 presented more frequently than model-2 and model-3, alterations (hyperchloraemic acidosis, uraemia, hyperammonemia and hypoalbumin) as well as affectation of upper urinary system for acute or chronic pyelonephritis.

  20. [Epidemiological aspects of tuberculosis in middle west of Madagascar].

    PubMed

    Rakotondramarina, D; Razafimalala, F; Andrianaivo, P; Rabeson, D; Andriatsiva, R; Andrianavalomahefa, W

    2000-01-01

    We conducted a 5-year (1989-1993) retrospective analysis on a series of patients screened and treated for tuberculosis in order to determine the epidemiological aspects of the disease in mid-western Madagascar. Pulmonary forms affected 97% of patients, and predominantly men (sex ratio: 1.4); 83% of patients with pulmonary tuberculosis were coughing up acido-alcoholo-resitant bacilli. Haemoptysis and general deterioration, the most frequently met pathological signs, were observed respectively in 62% and 24% of cases. This explains the high rate of hospitalisation (42%), especially for patients with difficult access to services. Significantly, in terms of socio-professional category, live-stock breeders and farmers represented 32% of notified cases, and cattle-traders 18%. We draw attention to the possible role played by Mycobacterium bovis in human case-findings in a region characterised by cattle-breeding.

  1. Adsorption mechanism of acids and bases in reversed-phase liquid chromatography in weak buffered mobile phases designed for liquid chromatography/mass spectrometry.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2009-03-01

    The overloaded band profiles of five acido-basic compounds were measured, using weakly buffered mobile phases. Low buffer concentrations were selected to provide a better understanding of the band profiles recorded in LC/MS analyses, which are often carried out at low buffer concentrations. In this work, 10 microL samples of a 50 mM probe solution were injected into C(18)-bonded columns using a series of five buffered mobile phases at (SW)pH between 2 and 12. The retention times and the shapes of the bands were analyzed based on thermodynamic arguments. A new adsorption model that takes into account the simultaneous adsorption of the acidic and the basic species onto the endcapped adsorbent, predicts accurately the complex experimental profiles recorded. The adsorption mechanism of acido-basic compounds onto RPLC phases seems to be consistent with the following microscopic model. No matter whether the acid or the base is the neutral or the basic species, the neutral species adsorbs onto a large number of weak adsorption sites (their saturation capacity is several tens g/L and their equilibrium constant of the order of 0.1 L/g). In contrast, the ionic species adsorbs strongly onto fewer active sites (their saturation capacity is about 1g/L and their equilibrium constant of the order of a few L/g). From a microscopic point of view and in agreement with the adsorption isotherm of the compound measured by frontal analysis (FA) and with the results of Monte-Carlo calculations performed by Schure et al., the first type of adsorption sites are most likely located in between C(18)-bonded chains and the second type of adsorption sites are located deeper in contact with the silica surface. The injected concentration (50 mM) was too low to probe the weakest adsorption sites (saturation capacity of a few hundreds g/L with an equilibrium constant of one hundredth of L/g) that are located at the very interface between the C(18)-bonded layer and the bulk phase. PMID:18976999

  2. The Mediterranean diet and micronutrient levels in depressive patients.

    PubMed

    Ibarra, Olga; Gili, Margalida; Roca, Miguel; Vives, Margalida; Serrano, María Jesús; Pareja, Antonio; García-Campayo, Javier; Gómez-Juanes, Rocío; García-Toro, Mauro

    2014-10-03

    Introducción: Se ha comunicado una correlación inversa entre depresión y el nivel sérico de algunos micronutrientes (selenio, zinc, hierro, magnesio, vitamina B y acido fólico). Además, otros estudios han señalado que la suplementar de estos micronutrientes puede mejorar la depresión. La dieta mediterránea proporciona una suficiente cantidad de los micronutrientes mencionados, aunque ningún estudio ha probado si la prescripción de dicha dieta puede incrementar los niveles de micronutrientes en pacientes depresivos. Objetivo: Examinar el impacto de recomendar un patrón dietético mediterráneo en los niveles de micronutrientes de pacientes deprimidos. Material y Métodos: 77 pacientes ambulatorios se aleatorizaron entre un grupo de intervención (recomendaciones higiénico-dietéticas sobre dieta, ejercicio, sueño y exposición solar) y un grupo control. La evolución fue evaluada antes y después de los seis meses del periodo de intervención. Resultados: Los niveles de selenio y de zinc fueron ligeramente bajos en la determinación basal y el nivel de selenio correlacionaba inversamente con la severidad de la depresión (r=-0.233; p=0.041). El grupo activo evolucionó mejor de la clínica depresiva. Sin embargo, no se observaron diferencias significativas en los niveles de micronutrientes después de la prescripción del patrón de dieta mediterránea probablemente a causa de una insuficiente adherencia. Conclusión: Los niveles séricos de selenio, zinc, hierro, magnesio vitamina B12 y acido fólico no aumentaron en pacientes depresivos seis meses después de prescribir un patrón de dieta mediterránea.

  3. Adsorption mechanism of acids and bases in reversed-phase liquid chromatography in weak buffered mobile phases designed for liquid chromatography/mass spectrometry.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2009-03-01

    The overloaded band profiles of five acido-basic compounds were measured, using weakly buffered mobile phases. Low buffer concentrations were selected to provide a better understanding of the band profiles recorded in LC/MS analyses, which are often carried out at low buffer concentrations. In this work, 10 microL samples of a 50 mM probe solution were injected into C(18)-bonded columns using a series of five buffered mobile phases at (SW)pH between 2 and 12. The retention times and the shapes of the bands were analyzed based on thermodynamic arguments. A new adsorption model that takes into account the simultaneous adsorption of the acidic and the basic species onto the endcapped adsorbent, predicts accurately the complex experimental profiles recorded. The adsorption mechanism of acido-basic compounds onto RPLC phases seems to be consistent with the following microscopic model. No matter whether the acid or the base is the neutral or the basic species, the neutral species adsorbs onto a large number of weak adsorption sites (their saturation capacity is several tens g/L and their equilibrium constant of the order of 0.1 L/g). In contrast, the ionic species adsorbs strongly onto fewer active sites (their saturation capacity is about 1g/L and their equilibrium constant of the order of a few L/g). From a microscopic point of view and in agreement with the adsorption isotherm of the compound measured by frontal analysis (FA) and with the results of Monte-Carlo calculations performed by Schure et al., the first type of adsorption sites are most likely located in between C(18)-bonded chains and the second type of adsorption sites are located deeper in contact with the silica surface. The injected concentration (50 mM) was too low to probe the weakest adsorption sites (saturation capacity of a few hundreds g/L with an equilibrium constant of one hundredth of L/g) that are located at the very interface between the C(18)-bonded layer and the bulk phase.

  4. Adsorption mechanism of acids and bases in reversed-phase liquid chromatography in weak buffered mobile phases designed for liquid chromatography/mass spectrometry

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2009-01-01

    The overloaded band profiles of five acido-basic compounds were measured, using weakly buffered mobile phases. Low buffer concentrations were selected to provide a better understanding of the band profiles recorded in LC/MS analyses, which are often carried out at low buffer concentrations. In this work, 10 {micro}L samples of a 50 mM probe solution were injected into C{sub 18}-bonded columns using a series of five buffered mobile phases at {sub W}{sup S}pH between 2 and 12. The retention times and the shapes of the bands were analyzed based on thermodynamic arguments. A new adsorption model that takes into account the simultaneous adsorption of the acidic and the basic species onto the endcapped adsorbent, predicts accurately the complex experimental profiles recorded. The adsorption mechanism of acido-basic compounds onto RPLC phases seems to be consistent with the following microscopic model. No matter whether the acid or the base is the neutral or the basic species, the neutral species adsorbs onto a large number of weak adsorption sites (their saturation capacity is several tens g/L and their equilibrium constant of the order of 0.1 L/g). In contrast, the ionic species adsorbs strongly onto fewer active sites (their saturation capacity is about 1 g/L and their equilibrium constant of the order of a few L/g). From a microscopic point of view and in agreement with the adsorption isotherm of the compound measured by frontal analysis (FA) and with the results of Monte-Carlo calculations performed by Schure et al., the first type of adsorption sites are most likely located in between C{sub 18}-bonded chains and the second type of adsorption sites are located deeper in contact with the silica surface. The injected concentration (50 mM) was too low to probe the weakest adsorption sites (saturation capacity of a few hundreds g/L with an equilibrium constant of one hundredth of L/g) that are located at the very interface between the C{sub 18}-bonded layer and the bulk

  5. Glass transition of adsorbed stereoregular PPMA by inverse gas chromatography at infinite dilution

    NASA Astrophysics Data System (ADS)

    Hamieh, T.; Rezzaki, M.; Grohens, Y.; Schultz, J.

    1998-10-01

    In this paper, we used inverse gas chromatography (IGC) at infinite dilution that proved to be a powerful technique to determine glass transition and other transitions of PMMA adsorbed on α-alumina. We highlighted the glass transition temperature of the system PMMA/α-Al2O3 with defined polymer tacticity at various covered surface fractions. Thus, the Tg of the adsorbed isotactic PMMA increases strongly as compared to the bulk value. The study of the physical chemical properties of PMMA/α-alumina revealed an important difference in the acidic and basic behaviour, in Lewis terms, of aluminium oxide covered by various concentrations of PMMA. It appears that there is a stabilisation of the physical chemical properties of PMMA/α-Al2O3 for a surface coverage above 50%. This study also highlighted an important effect of the tacticity of the polymer on the acid-base character of the system PMMA/Al2O3. Dans cet article, nous montrons que la chromatographie gazeuse inverse (CGI) à dilution infinie se révèle être une technique très intéressante pour la détermination de la transition vitreuse de polymères stéréoréguliers adsorbés sur des substrats solides tels que l'alumine. Nous avons mis en évidence des transitions attribuées aux phénomènes de relaxation béta, transition vitreuse et autres transitions des systèmes PMMA/Al2O3 de tacticité définie à différents taux de recouvrement. Ainsi, la Tg du PMMA isotactique adsorbé augmente de façon significative par rapport a celle du polymère massique. L'étude des propriétés physico-chimiques du système PMMA/Al2O3, révèle une différence importante dans le comportement acido-basique, au sens de Lewis, de l'alumine pour de taux de recouvrement en PMMA variables. Il apparaît qu'il y a stabilisation des propriétés physico-chimiques de PMMA/Al2O3 pour un taux de recouvrement en PMMA supérieur à 50 %. Cette étude a montré également une influence importante de la tacticité du polymère sur le

  6. Assessment of carbonic anhydrase IX expression and extracellular pH in B-cell lymphoma cell line models

    PubMed Central

    Chen, Liu Qi; Howison, Christine M.; Spier, Catherine; Stopeck, Alison T.; Malm, Scott W.; Pagel, Mark D.; Baker, Amanda F.

    2015-01-01

    The expression of carbonic anhydrase (CA IX) and it’s relation to acidosis in lymphomas has not been widely studied. We investigated the protein expression of CA IX in a human B-cell lymphoma tissue microarray, and in Raji, Ramos, and Granta 519 lymphoma cell lines and tumor models, while also investigating the relation with hypoxia. An imaging method, acidoCEST MRI, was used to estimate lymphoma xenograft extracellular pH (pHe). Our results showed that clinical lymphoma tissues and cell line models in vitro and in vivo had moderate CA IX expression. Although in vitro studies showed that CA IX expression was induced by hypoxia, in vivo studies did not show this correlation. Untreated lymphoma xenograft tumor pHe had acidic fractions, and an Acidity Score was qualitatively correlated with CA IX expression. Therefore, CA IX is expressed in B-cell lymphomas and is qualitatively correlated with extracellular acidosis in xenograft tumor models. PMID:25130478

  7. Using epilithic diatom communities to assess ecological condition of Xiangxi river system.

    PubMed

    Tang, Tao; Cai, Qinghua; Liu, Jiankang

    2006-01-01

    Assessment method for ecological condition of Xiangxi River system was studied by using 13 candidate metrics of epilithic diatom which can reflect conditions in pH, salinity, nitrogen uptake metabolism, oxygen requirements, saprobity, trophic state, morphological character and pollution tolerant capability etc. By one-way ANOVA, the metrics of relative abundance of acido-bionotic algae (ACID), freshwater algae (FRESH), high oxygen requirement (HIGH-O), eutraphentic state (EUTRA) and mobile taxa (MOBILE) were suitable for distinguishing sites in different conditions. Then, the river diatom index (RDI) composed of these five metrics was used to evaluate ecological condition of the river. The results showed that the healthiest sites were in the Guanmenshan Natural Reserve (with the mean RDI of 79.73). The sites located in tributary of Jiuchong River also owned excellent state (mean RDI of 78.25). Mean RDI of another tributary - Gufu River and the main river were 70.85 and 68.45 respectively, and the unhealthiest tributary was Gaolan River (with mean RDI of 65.64). The mean RDI for all the 51 sites was 71.40. The competence of RDI was discussed with comparison of evaluation results of DAIpo and TDI, it can be concluded that multimetrics is more competent in assessment task.

  8. Survey of several methods deproteinizing human plasma before and within the chloroformate-mediated treatment of amino/carboxylic acids quantitated by gas chromatography.

    PubMed

    Hušek, Petr; Svagera, Zdeněk; Hanzlíková, Dagmar; Simek, Petr

    2012-01-01

    Trichloroacetic acid, perchloric acid, phosphotungstic acid, acetonitrile, methanol and some other organic solvents were evaluated for their ability to provide protein and lipid-free plasma supernatants. The residual proteins, total cholesterol and triacylglycerols were assayed in the supernatant on a Beckman Analyzer instrument. The free cholesterol and the neutral lipids were further analyzed by means of high-temperature GC analysis. The conditions for the deproteinizing step were optimized for minimal lipoprotein disruption. A substantial difference regarding contamination by the lipids was found if the plasma supernatant or the whole serum were treated with an alkyl chloroformate reagent. Three plasma sulfur amino acids and the aromatic ones were chosen as model compounds to evaluate compatibility of the precipitation methods with a subsequent methyl chloroformate-mediated derivatization and GC-MS analysis. The results of the total homocysteine assay matched well with that obtained using a commercial immunoassay. Precipitation with trichloroacetic acid has proven to be a method of choice for the analysis of the acido-basic analytes by GC-MS via chloroformates.

  9. Dark oxidation of dissolved gaseous mercury in polar ice mimics.

    PubMed

    O'Concubhair, Ruairí; O'Sullivan, Daniel; Sodeau, John R

    2012-05-01

    The low-temperature chemistry associated with environmentally available mercury has recently attracted considerable scientific interest due to the discovery of systemic gas-phase mercury depletion events (MDEs) which occur periodically at the poles. However, the fate of the mercury once it enters the snowpack is not fully understood, even its chemical speciation has yet to be well characterized. An issue that is of particular concern in frozen environments is the transformation of elemental mercury (Hg(0)) to more bioavailable oxidized forms, which can then be methylated by biotic and abiotic processes. The resulting methyl mercury species produced can bioaccumulate through the food chain and the health effects of this on humans and mammals have been well-documented. During the current study, a novel set of "freeze-induced" pathways, which can potentially affect the reactivity of dissolved gaseous mercury (DGM) were followed. The experiments were performed using environmentally relevant cosolutes at appropriate concentration levels and temperatures. Evidence is thereby presented that due to rate accelerations associated with the operation of the freeze-concentration effect, DGM is oxidized to Hg(2+) ions when frozen in the presence of a variety of materials including hydrogen peroxide, nitrous acid and the sulfuric acid/O(2) couple.

  10. [Phenotypic variations in Aicardi-Goutieres syndrome caused by RNASEH2B gene mutations: report of two new cases].

    PubMed

    Ortiz-Madinaveitia, Saturnino; Conejo-Moreno, David; López-Pisón, Javier; Peña-Segura, José Luis; Serrano-Madrid, M Luisa; Durán-Palacios, Ingrid C; Peláez-Cabo, Pilar

    2016-02-16

    Introduccion. El sindrome de Aicardi-Goutieres es un trastorno inmunitario raro debido a mutaciones en siete genes que codifican proteinas llamadas TREX1, el complejo ribonucleasa H2, SAMHD1, ADAR e IFIH1 (MAD5), las cuales estan implicadas en el metabolismo de los acidos nucleicos. A continuacion se presentan dos nuevos casos por mutacion en el gen RNASEH2B, uno de los cuales presenta una mutacion no descrita hasta la fecha. Casos clinicos. Caso 1: varon que consulto porque desde los 5 meses, coincidiendo con cuadros febriles de repeticion, presentaba perdida de los items madurativos adquiridos hasta la fecha. Caso 2: niño de 4 meses que desde los 2 meses mostraba gran irritabilidad con dificultades en la alimentacion, asociado a un grave retraso psicomotor. En ambos casos se constato un aumento de las pterinas en el liquido cefalorraquideo, principalmente de la neopterina, con calcificaciones en los ganglios basales. El diagnostico se confirmo mediante secuenciacion del gen RNASEH2B; el caso 2 presentaba una mutacion no descrita en la literatura medica. Conclusiones. Los casos corresponden a la descripcion clasica realizada por Aicardi-Goutieres. Debe tenerse en cuenta este sindrome ante un paciente con un cuadro de encefalopatia subaguda de comienzo en el primer año de vida, distonia/espasticidad en grado variable e importante afectacion/regresion del desarrollo psicomotor, especialmente si asocia aumento de las pterinas (neopterina) en el liquido cefalorraquideo y calcificaciones en los ganglios basales.

  11. [Benign myoclonic epilepsy in infancy: natural history and behavioral and cognitive outcome].

    PubMed

    Domínguez-Carral, Jana; García-Peñas, Juan José; Pérez-Jiménez, M Ángeles; Fournier-Del Castillo, M Concepción; Carreras-Sáez, Inmaculada; Jiménez-Echevarría, Saioa

    2014-02-01

    Introduccion. La epilepsia mioclonica benigna del lactante (EMBL) es un sindrome electroclinico de caracteristicas homogeneas y bien definidas, considerado clasicamente de buen pronostico. Sin embargo, en los ultimos años se han publicado estudios con resultados variables en cuanto a evolucion neuropsicologica. Objetivo. Analizar la evolucion natural y el pronostico neurocognitivo y conductual de los pacientes con EMBL. Pacientes y metodos. Estudio retrospectivo de 10 pacientes con EMBL, con un periodo de seguimiento de mas de cinco años, durante los cuales se realizo una evaluacion neurocognitiva y conductual. Resultados. En el 60% de los pacientes las crisis se controlaron con acido valproico en monoterapia, y el 80% no presento nuevas crisis durante su seguimiento. El cociente intelectual de la cohorte se situo entre 74 y 93; tres pacientes tuvieron un cociente intelectual en rango de inteligencia limite, y seis, en rango de inteligencia media-baja. Nueve pacientes cumplieron criterios de trastorno por deficit de atencion/hiperactividad y dos asociaban otro trastorno del aprendizaje, uno de ellos trastorno de aprendizaje no verbal, y el otro, trastorno especifico de la lectoescritura. Todos los pacientes presentaron datos de pobre coordinacion motriz y visuoespacial, y tres fueron diagnosticados de trastorno de conducta. Conclusiones. El termino 'benigno' en la EMBL debe utilizarse con precaucion en cuanto a su pronostico neurocognitivo y conductual. El inicio precoz y un peor control de las crisis podrian suponer factores de riesgo de evolucion neuropsicologica desfavorable.

  12. Structures of nitrato-(2-hydroxybenzaldehydo) (2,2 Prime -bipyridyl)copper and nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper

    SciTech Connect

    Chumakov, Yu. M.; Paladi, L. G.; Antosyak, B. Ya.; Simonov, Yu. A.; Tsapkov, V. I.; Bocelli, G.; Gulea, A. P.; Ginju, D.; Palomares-Sanchez, S. A.

    2011-03-15

    Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2 Prime -bipyridyl)copper (I) and nitrato-(2-hydroxybenzaldehydo)(2,2 Prime -bipyridyl)copper (II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2 Prime -bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO{sub 2} groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2 Prime -bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.

  13. Gas-phase structures and thermochemistry of neutral histidine and its conjugated acid and base.

    PubMed

    Riffet, Vanessa; Bouchoux, Guy

    2013-04-28

    Extensive exploration of the conformational space of neutral, protonated and deprotonated histidine has been conducted at the G4MP2 level. Theoretical protonation and deprotonation thermochemistry as well as heats of formation of gaseous histidine and its ionized forms have been calculated at the G4 level considering either the most stable conformers or an equilibrium population of conformers at 298 K. These theoretical results were compared to evaluated experimental determinations. Recommended proton affinity and protonation entropy deduced from these comparisons are PA(His) = 980 kJ mol(-1) and ΔpS(His) ∼ 0 J mol(-1) K(-1), thus leading to a gas-phase basicity value of GB(His) = 947.5 kJ mol(-1). Similarly, gas phase acidity parameters are ΔacidH(o)(His) = 1373 kJ mol(-1), ΔacidS(His) ∼ 10 J mol(-1) K(-1) and ΔacidG(o)(His) = 1343 kJ mol(-1). Computed G4 heats of formation values are equal to -290, 265 and -451 kJ mol(-1) for gaseous neutral histidine and its protonated and deprotonated forms, respectively. The present computational data correct, and complete, previous thermochemical parameter estimates proposed for gas-phase histidine and its acido-basic properties.

  14. Molluscicidal activity of various solvent extracts from Solanum nigrum var. villosum L. aerial parts against Galba truncatula.

    PubMed

    Hammami, H; Mezghani-Jarraya, R; Damak, M; Ayadi, A

    2011-02-01

    Molluscicidal activity of Solanum nigrum var. villosum (morelle velue) extracts and their fractions were tested against the mollusca gastropoda Galba truncatula intermediate host of Fasciola hepatica. The results indicated that the hydro-methanol (MeOH-H2O) immature fruit extract possess the highest molluscicidal activity (LC50 = 3.96 mg/L) against Galba truncatula compared with other tested compounds. After acido-basic treatment, the methanolic extract fraction isolated from the immature fruits and the richest in alkaloids was the most toxic (LC50 = 1.65 mg/L). The fractions richest in saponosides obtained from the hydromethanolic and methanolic extracts of immature fruits showed interesting molluscicidal activities (LC50 = 6.15 mg/L and LC50 = 7.91 mg/L, respectively). The observed molluscicide activity could be attributed to the presence of alkaloids or saponosides. So, the immature fruits of Solanum nigrum var. villosum could be substrates of choice for molluscicide activity. In addition, total alkaloids and saponosides present in this plant deserve further investigations in order to identify the active principles and demonstrate their activities on mollusks in their natural habitat. According to the World Health Organization's guidelines on screening for plant molluscicides, use of these fractions may add to the arsenal of methods to control snail transmitting fasciolosis in tropical and Third World countries where fasciolosis is a common disease.

  15. Light-induced copper(II) coordination by a bicyclic tetraaza chelator through a ligand-to-metal charge-transfer reaction.

    PubMed

    Holm-Jørgensen, Jacob R; Jensen, Mikael; Bjerrum, Morten J

    2011-12-19

    To enable utilization of the broad potential of copper isotopes in nuclear medicine, rapid and robust chelation of the copper is required. Bowl adamanzanes (bicyclic tetraaza ligands) can form kinetically stable copper complexes, but they are usually formed at low rates unless high pH values and high temperatures are applied. We have investigated the effects of the variation in the pH, different anions, and UV irradiation on the chelation rate. UV spectra of mixtures of Cu(2+) and [2(4).3(1)]adz in water show the existence of a long-lived two-coordinated copper(II) intermediate (only counting coordinated amine groups) at pH above 6. These findings are supported by pH titrations of mixtures of Cu(2+) and [2(4).3(1)]adz in water. Irradiation of this complex in the ligand-to-metal charge-transfer (LMCT) band by a diode-array spectrophotometer leads to photodeprotonation and subsequently to formation of the four-coordinated copper(II) complex at a rate up to 7800-fold higher at 25 °C than in the dark. Anions in the solution were found to have three major effects: competitive inhibition due to Cu(II) binding anions, inhibition of the photoinduced transchelation from UV-absorbing anions, and photoredox inhibition from acido ligands capable of acting as electron donors in LMCT reactions. Dissolved O(2) was also found to result in photoredox inhibition.

  16. Structures of nitrato-(2-hydroxybenzaldehydo) (2,2'-bipyridyl)copper and nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2'-bipyridyl)copper

    NASA Astrophysics Data System (ADS)

    Chumakov, Yu. M.; Paladi, L. G.; Antosyak, B. Ya.; Simonov, Yu. A.; Tsapkov, V. I.; Bocelli, G.; Gulea, A. P.; Ginju, D.; Palomares-Sanchez, S. A.

    2011-03-01

    Nitrato-(2-hydroxy-5-nitrobenzaldehydo)(2,2'-bipyridyl)copper ( I) and nitrato-(2-hydroxybenzaldehydo)(2,2'-bipyridyl)copper ( II) were synthesized and characterized by X-ray diffraction. The coordination polyhedron of the central copper atom in complex I can be described as a distorted tetragonal pyramid whose base is formed by the phenol and carbonyl oxygen atoms of the monodeprotonated 2-hydroxy-5nitrobenzaldehyde molecule and the nitrogen atoms of the 2,2'-bipyridyl ligand and whose apex is occupied by the oxygen atom of the nitrato group. In the crystal structure, complexes I are linked by the acido ligands and the NO2 groups of the aldehyde molecule into infinite chains. In complex II, the central copper atom is coordinated by 2-hydroxybenzaldehyde, 2,2'-bipyridyl, and the nitrato group, resulting in the formation of centrosymmetric dimers. The coordination polyhedron of the central copper atom can be described as a bipyramid (4 + 1 + 1) with the same base as in complex I. The axial vertices of the bipyramid are occupied by the oxygen atom of the nitrato group and the bridging phenol oxygen atom of the adjacent complex related to the initial complex by a center of symmetry. In the crystal structure, complexes II are hydrogen bonded into infinite chains.

  17. Evaluation of redox mediators for amperometric biosensors: Ru-complex modified carbon-paste/enzyme electrodes.

    PubMed

    Ivanova, Ekaterina V; Sergeeva, Viktorya S; Oni, Joshua; Kurzawa, Christian; Ryabov, Alexander D; Schuhmann, Wolfgang

    2003-08-01

    The properties of reagentless amperometric biosensors are mainly governed by the interaction of the used redox enzyme and the redox mediators used to facilitate the electron-transfer reaction. Both the used redox mediators and the redox enzymes differ concerning their hydrophilicity and their properties within the matrix of a carbon-paste electrode. Since there is no general procedure which is applicable for any enzyme in combination with any redox mediator, optimisation is necessary for each possible combination. Three approaches for the development of biosensors were investigated using carbon-paste electrodes enriched with redox mediator as a base in all sensor architectures. A class of redox mediators with the common formula Ru(LL)(2)(X)(2) (where LL are 1,10-phenantroline or 2,2'-bipyridine type ligands, and X is an acido ligand) was investigated. In the first approach, enzymes were integrated into the carbon paste; in the second, the enzymes were adsorbed on the surface of the mediator-containing carbon-paste electrode and held in place by a Nafion film; and in the third approach, enzymes were entrapped in polymer films, which were electrochemically deposited onto the electrode's surface. The properties of the obtained biosensors strongly depend on the sensor architecture and the specific features of the used enzyme. Thus, our investigation using three different sensor architectures can provide valuable information about the possible interaction between a specific enzyme and a redox mediators with specific properties.

  18. Correlation between substratum roughness and wettability, cell adhesion, and cell migration.

    PubMed

    Lampin, M; Warocquier-Clérout; Legris, C; Degrange, M; Sigot-Luizard, M F

    1997-07-01

    Cell adhesion and spreading of chick embryo vascular and corneal explants grown on rough and smooth poly (methyl methacrylate) (PMMA) were analyzed to test the cell response specificity to substratum surface properties. Different degrees of roughness were obtained by sand-blasting PMMA with alumina grains. Hydrophilic and hydrophobic components of the surface free energy (SFE) were calculated according to Good-van Oss's model. Contact angles were determined using a computerized angle meter. The apolar component of the SFE gamma s(LW), increased with a slight roughness whereas the basic component, gamma s-, decreased. The acido-basic properties disappeared as roughness increased. Incubation of PMMA in culture medium, performed to test the influence if the biological environment, allowed surface adsorption of medium proteins which annihilated roughness effect and restored hydrophilic properties. An organotypic culture assay was carried out in an attempt to relate the biocompatibility to substratum surface state. Cell migration was calculated from the area of cell layer. Cellular adhesion was determined by measuring the kinetic of release of enzymatically dissociated cells. A slight roughness raised the migration are to an upper extent no matter which cell type. Enhancement of the cell adhesion potential was related to the degree of roughness and the hydrophobicity.

  19. [Blood gas and acid-base changes and rhythmologic tolerance of acetate and bicarbonate hemodialysis using a standard dialyser with high sodium and control of ultrafiltration].

    PubMed

    Westeel, P F; Coevoet, B; Bens, J L; Neuville, M; Morinière, P; Fievet, P; Dkhissi, H; Fournier, A

    1983-01-01

    In order to demonstrate a possible superiority of bicarbonate dialysis (HDB) over acetate dialysis (HDA) in conditions of standard dialysis (4 hours on a 1 m2 cuprophan dialyser) but with a bath rich in sodium (143 mEq/l) and control of ultrafiltration, we have compared 2 sequences of 3 runs of HDA and HDB with these conditions in 8 patients as regards their acido-basic and cardiologic parameters (continuous monitoring of ECG by Holter, regular measurement of blood pressure). Acid base balance study in AHD led to the distinction of 2 groups according to wether their plasma bicarbonate increased or decreased during the run. Rythmological tolerance was the same in BHD and AHD, wether all patients or both groups were considered. Heart rate was however slightly but significantly higher during AHD than during BHD, in the patients whose plasma bicarbonate decreased. In conclusion, the benefit of HDB is not remarkable when HDA is performed not only in standard conditions but also with a bath rich in sodium and with control of ultrafiltration.

  20. Sorption of selenium anionic species on apatites and iron oxides from aqueous solutions.

    PubMed

    Duc, Myriam; Lefevre, Gregory; Fedoroff, Michel; Jeanjean, Janine; Rouchaud, J C; Monteil-Rivera, Fanny; Dumonceau, Jacques; Milonjic, Slobodan

    2003-01-01

    The sorption of selenite and selenate ions from aqueous solutions was investigated on hydroxyapatite, fluorapatite, goethite and hematite, in order to simulate the behavior of radioactive selenium in natural or artificial sorbing media. Correlation studies with acido-basic properties and solubility of the solids were also performed. The sorption is pH dependant, but these solids are very efficient for retaining selenite at pH values generally encountered in natural waters, with however higher K(d) values for oxides than apatites. Selenate ions are much less sorbed than selenite. Several methods such as electron microscopy and spectroscopic techniques were used to identify the sorption mechanisms. In the case of hydroxyapatite, sorption proceeds by substitution of phosphate groups in the lattice of the apatite crystal in the superficial layers of the solid. In the case of goethite and hematite, sorption can be interpreted and modeled by a surface complexation process, but there is a discrepancy between sorption site densities for selenite and for protons.

  1. A prototype of volume-controlled tidal liquid ventilator using independent piston pumps.

    PubMed

    Robert, Raymond; Micheau, Philippe; Cyr, Stéphane; Lesur, Olivier; Praud, Jean-Paul; Walti, Hervé

    2006-01-01

    Liquid ventilation using perfluorochemicals (PFC) offers clear theoretical advantages over gas ventilation, such as decreased lung damage, recruitment of collapsed lung regions, and lavage of inflammatory debris. We present a total liquid ventilator designed to ventilate patients with completely filled lungs with a tidal volume of PFC liquid. The two independent piston pumps are volume controlled and pressure limited. Measurable pumping errors are corrected by a programmed supervisor module, which modifies the inserted or withdrawn volume. Pump independence also allows easy functional residual capacity modifications during ventilation. The bubble gas exchanger is divided into two sections such that the PFC exiting the lungs is not in contact with the PFC entering the lungs. The heating system is incorporated into the metallic base of the gas exchanger, and a heat-sink-type condenser is placed on top of the exchanger to retrieve PFC vapors. The prototype was tested on 5 healthy term newborn lambs (<5 days old). The results demonstrate the efficiency and safety of the prototype in maintaining adequate gas exchange, normal acido-basis equilibrium, and cardiovascular stability during a short, 2-hour total liquid ventilator. Airway pressure, lung volume, and ventilation scheme were maintained in the targeted range.

  2. An environmentally friendly method to remove and utilize the highly toxic strychnine in other products based on proton-transfer complexation

    NASA Astrophysics Data System (ADS)

    Adam, Abdel Majid A.; Refat, Moamen S.; Saad, Hosam A.; Hegab, Mohamed S.

    2015-12-01

    The study of toxic and carcinogenic substances represents one of the most demanding areas in human safety, due to their repercussions for public health. There is great motivation to remove and utilize these substances in other products instead of leaving them contaminate the environment. One potentially toxic compound for humans is strychnine (Sy). In the present study, we attempted to establish a quick, simple, direct and efficient method to remove and utilize discarded Sy in other products based on proton-transfer complexation. First, Sy was reacted with the acido organic acceptors PA, DNBA and CLA. Then, the resultant salts were direct carbonized into carbon materials. Also, this study provides an insight into the structure and morphology of the obtained products by a range of physicochemical techniques, such as UV-visible, IR, 1H NMR and 13C NMR spectroscopies; XRD; SEM; TEM; and elemental and thermal analyses. Interestingly, the complexation of Sy with the PA or DNBA acceptor leads to a porous carbon material, while its complexation with CLA acceptor forms non-porous carbon product.

  3. Inhibition of Neutral red photolysis with different antioxidants.

    PubMed

    Rimpapa, Zlatan; Sofić, Emin; Sapcanin, Aida; Toromanović, Jasmin; Tahirović, Ismet

    2007-02-01

    Neutral red is a dye the azine structure which has been used as an acido-base indicator and a dye in histochemistry. In 1960 Goldhaber introduced Neutral red into the medium of resorbing bone cultures to localize the osteoclast in the living cultures. Using time-lapse microcinematography in order to follow the osteoclasts, he reported excellent contrast could be obtained with Neutral red due to the avidity of osteoclasts for this dye. Unfortunately, however, the photodynamic effect resulting from subsequent exposure of these cultures to light precluded this approach, and again in 1963. it was observed that the death of the osteoclasts was probably due to a photodynamic effect related to the dye in the cell, the presence of oxygen and the frequent exposure of light by our time-lapse photography. VIS and UV irradiation induced photolysis of Neutral red, and from Neutral red cation produced with photons a Neutral red radical. This Neutral red radical can be inhibited with action of an antioxidant, such as melatonin, glutathione, ascorbic acid, E vitamin, etc. We developed an assay with Neutral red photolysis which utilizes a VIS and UV irradiation technique for quantification the inhibition of photolysis with action of an antioxidant. In this method Neutral red acts double, as a free radical generator and as a photosensitizer.

  4. Operation of the ISO-DALT system: Seventh edition

    SciTech Connect

    Tollaksen, S.L.; Anderson, N.L.; Anderson, N.G.

    1984-05-01

    The ISO-DALT system of two-dimensional electrophoresis was developed as a series of modifications of the original technique of O'Farrell. We have written a series of recipes and more detailed laboratory procedures that incorporate refinements and ''tricks of the trade'' as they have developed during our use of the system. The present collection is the seventh version in this series and represents the state of art as of May 1984. The seventh edition has been prepared to incorporate the changes that we have found helpful, as well as to add a few new sections such as silver staining, transfer gels, ACIDOs, and BASOs. Although these directions are specific for our laboratory, we hope that they will be helpful in other laboratories as well. Although some disagreement still exists, we recommend that gel patterns be oriented with acid isoelectric points (pIs) to the left and high sodium dodecyl sulfate (SDS) molecular weights at the top. This results in a system of pI and molecular weight values that run according to the Cartesian convention and facilitates the use of the charge and molecular weight standards described herein. 67 refs., 14 figs.

  5. Characterization, cloning, and evolutionary history of the chloroplast and cytosolic class I aldolases of the red alga Galdieria sulphuraria.

    PubMed

    Gross, W; Lenze, D; Nowitzki, U; Weiske, J; Schnarrenberger, C

    1999-04-01

    Two fructose-1,6-bisphosphate aldolases from the acido- and thermophilic red alga Galdieria sulphuraria were purified to apparent homogeneity and N-terminally microsequenced. Both aldolases had similar biochemical properties such as Km (FBP) (5.6-5.8 microM) and molecular masses of the native enzymes (165kDa) as determined by size exclusion chromatography. The subunit size of the purified aldolases, as determined by SDS-PAGE, was 42kDa for both aldolases. The isoenzymes were not inhibited by EDTA or affected by cysteine or potassium ions, implying that they belong to the class I group of aldolases, while other red algae are known to have one class I and one class II aldolase inhibited by EDTA. cDNA clones of the cytosolic and plastidic aldolases were isolated and sequenced. The gene for the cytosolic isoenzyme contained a 303bp untranslated leader sequence, while the gene for the plastidic isoenzyme exhibited a transit sequence of 56 amino-acid residues. Both isoenzymes showed about 48% homology in the deduced amino-acid sequences. A gene tree relates both aldolases to the basis of early eukaryotic class I aldolases. The phylogenetic relationship to other aldolases, particularly to cyanobacterial class II aldolases, is discussed.

  6. [Shmakovka narzan mineral water in the treatment of chronic pyelonephritis in children].

    PubMed

    Olofinskiĭ, L A; Alekseeva, I L

    1990-01-01

    The impact of "Pasechnyĭ" spa of the Shmakovka health resort on the circadian urinary output, renal excretion of magnesium, calcium, nonorganic phosphorus, oxalates, uric acid, phospholipids, acido- and ammoniogenases, daily fluctuations of urinary pH was studied for the first time in 65 children with chronic pyelonephritis. In the presence of spa treatment the authors revealed a 75-100 per cent increase in the circadian urinary output, urinary excretion of magnesium, uric acid, ammonia, titrated acids, a decrease in the levels of calcium, oxalates, nonorganic phosphorus and acidification of the urine at 9 o'clock in the morning mainly in children with primary pyelonephritis and at 9 and 6 o'clock in the morning in patients with concurrent uricosuria. Other parameters were not significantly different from those in the controls. Acidification of the urine in the presence of high uricosuria resulted in crystalluria of urates and oxalates in 26.31 per cent of patients with the concurrent urate diathesis. The water of Shmakovka mineral springs is recommended for patients with primary pyelonephritis, phosphaturia and calcium oxalate crystalluria with alkaline reaction of the urine and unjustified for those who suffered from urate diathesis.

  7. [The essence of essential tremor: neurochemical bases].

    PubMed

    Gironell, A; Marin-Lahoz, J

    2016-06-01

    Introduccion. El temblor esencial es el trastorno del movimiento mas frecuente en el adulto. Se ha considerado una enfermedad benigna, pero puede ocasionar una importante discapacidad fisica y psicosocial. El tratamiento farmacologico sigue siendo poco satisfactorio. Su etiologia, fisiopatologia y anatomia siguen sin conocerse del todo. Objetivo. El conocimiento de las bases neuroquimicas es fundamental para el desarrollo de terapias mas eficaces. Se revisan los conocimientos actuales en este campo a fin de incentivar nuevas investigaciones e ideas que permitan mejorar la comprension de la enfermedad y que fomenten el desarrollo de nuevas terapias farmacologicas. Desarrollo. Se revisan los trabajos realizados hasta la fecha en humanos y en modelos animales de neurotransmisores (acido gamma-aminobutirico, glutamato, noradrenalina, serotonina, adenosina), proteinas y otros fenomenos neuroquimicos, como los canales de calcio de tipo T en el temblor esencial. Conclusiones. Se han descrito cuatro disfunciones neuroquimicas que acontecerian basicamente en el cerebelo y el nucleo olivar inferior: alteracion del sistema gabergico, aumento del rebote postinhibitorio mediante corrientes de calcio de tipo T, disminucion de los mecanismos de inhibicion neuronal y aumento de la actividad de los neurotransmisores excitatorios. Estas disfunciones neuroquimicas comportarian un aumento de la actividad de las neuronas profundas cerebelosas con actividad oscilatoria, que se trasladaria al nucleo del talamo y a la corteza motora, y comportarian la aparicion del temblor. Son necesarios nuevos estudios para poder confirmar estas hipotesis y seguir avanzando para conseguir tratamientos farmacologicos mas eficaces para los pacientes con temblor esencial.

  8. Molluscicidal activity of various solvent extracts from Solanum nigrum var. villosum L. aerial parts against Galba truncatula

    PubMed Central

    Hammami, H.; Mezghani-Jarraya, R.; Damak, M.; Ayadi, A.

    2011-01-01

    Molluscicidal activity of Solanum nigrum var. villosum (morelle velue) extracts and their fractions were tested against the mollusca gastropoda Galba truncatula intermediate host of Fasciola hepatica. The results indicated that the hydro-methanol (MeOH-H2O) immature fruit extract possess the highest molluscicidal activity (LC50 = 3.96 mg/L) against Galba truncatula compared with other tested compounds. After acido-basic treatment, the methanolic extract fraction isolated from the immature fruits and the richest in alkaloids was the most toxic (LC50 = 1.65 mg/L). The fractions richest in saponosides obtained from the hydromethanolic and methanolic extracts of immature fruits showed interesting molluscicidal activities (LC50 = 6.15 mg/L and LC50 = 7.91 mg/L, respectively). The observed molluscicide activity could be attributed to the presence of alkaloids or saponosides. So, the immature fruits of Solanum nigrum var. villosum could be substrates of choice for molluscicide activity. In addition, total alkaloids and saponosides present in this plant deserve further investigations in order to identify the active principles and demonstrate their activities on mollusks in their natural habitat. According to the World Health Organization’s guidelines on screening for plant molluscicides, use of these fractions may add to the arsenal of methods to control snail transmitting fasciolosis in tropical and Third World countries where fasciolosis is a common disease. PMID:21395207

  9. Self-powered biosensor for ascorbic acid with a Prussian blue electrochromic display.

    PubMed

    Zloczewska, Adrianna; Celebanska, Anna; Szot, Katarzyna; Tomaszewska, Dorota; Opallo, Marcin; Jönsson-Niedziolka, Martin

    2014-04-15

    We report on the development of a nanocarbon based anode for sensing of ascorbic acid (AA). The oxidation of AA on this anode occurs at a quite low overpotential which enables the anode to be connected to a biocathode to form an ascorbic acid/O2 biofuel cell that functions as a self-powered biosensor. In conjunction with a Prussian blue electrochromic display the anode can also work as a truly self-powered sensor. The oxidation of ascorbic acid at the anode leads to a reduction of the Prussian blue in the display. The reduced form of Prussian blue, called Prussian white, is transparent. The rate of change from blue to colourless is dependent on the concentration of ascorbic acid. The display can easily be regenerated by connecting it to the biocathode which returns the Prussian blue to its oxidized form. In this way we have created the first self-powered electrochromic sensor that gives quantitative information about the analyte concentration. This is demonstrated by measuring the concentration of ascorbic acid in orange juice. The reported quantitative read-out electrochromic display can serve as a template for the creation of cheap, miniturizable sensors for other relevant analytes.

  10. Dietary potential renal Acid load in venezuelan children.

    PubMed

    López-Sayers, Mayerling; Bernal, Jennifer; López, Michelle

    2015-05-01

    Objetivo: Determinar y analizar la carga acida potencial renal de la dieta (Potential Renal Acid Load PRAL) y el patron de alimentacion de ninos entre 1 a 6 anos aparentemente sanos. Métodos: Se seleccionaron segun conveniencia a padres de 52 ninos asistentes a una consulta de ninos sanos. La calidad de la dieta y el patron de alimentacion se evaluo mediante un recordatorio de 24 horas y un cuestionario de frecuencia de alimentos. Se calculo la ingesta de macronutrientes y grupos de alimentos, como carnes, lacteos, frutas y verduras. La ingesta de nutrientes se comparo con las recomendaciones de energia y nutrientes. El PRAL se determino segun el metodo de Remer y Manz, para determinar la carga acida de la dieta. Se aplico estadistica descriptiva y correlaciones entre el PRAL, nutrientes y grupos de alimentos. Resultados: La ingesta de proteinas, de leche y de carnes fue elevada, mientras que la ingesta de rutas y hortalizas fue baja. El PRAL fue positivo en 92% de los ninos, se asocio con mayor ingesta de energia, proteinas, grasas, carne y lacteos. La ingesta de proteinas fue > 2,5 g/kg/ dia en 46,2% de los ninos. Los grupos de alimentos con mayor desequilibrio debido a exceso fueron la carne y los productos lacteos, mientras que por deficit fue el grupo de frutas y hortalizas. Conclusión: La dieta se caracteriza por una elevada carga de acido o PRAL, lo que aumenta el riesgo de acidosis sistemica y sus consecuencias metabolicas.

  11. A prototype of volume-controlled tidal liquid ventilator using independent piston pumps.

    PubMed

    Robert, Raymond; Micheau, Philippe; Cyr, Stéphane; Lesur, Olivier; Praud, Jean-Paul; Walti, Hervé

    2006-01-01

    Liquid ventilation using perfluorochemicals (PFC) offers clear theoretical advantages over gas ventilation, such as decreased lung damage, recruitment of collapsed lung regions, and lavage of inflammatory debris. We present a total liquid ventilator designed to ventilate patients with completely filled lungs with a tidal volume of PFC liquid. The two independent piston pumps are volume controlled and pressure limited. Measurable pumping errors are corrected by a programmed supervisor module, which modifies the inserted or withdrawn volume. Pump independence also allows easy functional residual capacity modifications during ventilation. The bubble gas exchanger is divided into two sections such that the PFC exiting the lungs is not in contact with the PFC entering the lungs. The heating system is incorporated into the metallic base of the gas exchanger, and a heat-sink-type condenser is placed on top of the exchanger to retrieve PFC vapors. The prototype was tested on 5 healthy term newborn lambs (<5 days old). The results demonstrate the efficiency and safety of the prototype in maintaining adequate gas exchange, normal acido-basis equilibrium, and cardiovascular stability during a short, 2-hour total liquid ventilator. Airway pressure, lung volume, and ventilation scheme were maintained in the targeted range. PMID:17117053

  12. The effect of pH on the synthesis of stable Cu2O/CuO nanoparticles by sol-gel method in a glycolic medium

    NASA Astrophysics Data System (ADS)

    Zayyoun, N.; Bahmad, L.; Laânab, L.; Jaber, B.

    2016-05-01

    In this work, we demonstrate that using a glycolic medium, both stable CuO and Cu2O nanoparticles can be elaborated from Cu colloidal particles by adjusting their chemical environment, in particular the acido-basicity of the solution. In this context, the effect of pH on the sol-gel synthesis of Cu2O/CuO NPs was investigated. XRD results confirmed the formation of pure Cu2O with a cubic structure at lower pH (pH ≤ 6), whereas the pure monoclinic CuO was formed at higher pH (pH ≥ 12). TEM image indicates that the as-formed CuO NPs in basic pH are spherical in shape and their average size is found to be in the range of 4.5 nm. However, the as-obtained Cu2O NPs in acid pH are cubical, with an average diameter of about 3 nm, and agglomerated into large spherical particles under the effect of ethylene glycol. Using the UV-Vis spectroscopy, the measured band gap energies of the prepared Cu2O and CuO NPs are 2.07 and 4.08 eV respectively. FTIR results confirm the purity of the synthesized CuO and Cu2O nanoparticles.

  13. [Characteristics of patients with refractory epilepsy attended in a tertiary referral center in Costa Rica].

    PubMed

    Sanabria-Castro, A; Henriquez-Varela, F; Lara-Maier, S; Monge-Bonilla, C; Sittenfeld-Appel, M

    2016-07-16

    Introduccion. El 30% de los pacientes con epilepsia presenta convulsiones recurrentes, porcentaje que representa aproximadamente a 15 millones de personas en el mundo y constituye una poblacion escasamente descrita. Objetivo. Caracterizar sociodemografica y clinicamente la poblacion de pacientes diagnosticados con epilepsia refractaria en un hospital terciario de Costa Rica. Pacientes y metodos. Se analizan los registros medicos de los pacientes con epilepsia refractaria valorados en la unidad de epilepsia del Hospital San Juan de Dios de la Caja Costarricense del Seguro Social desde agosto de 2012 a octubre de 2014. Resultados. Se incluyen los expedientes clinicos de 91 pacientes. La edad media de inicio fue de 13,1 ± 11,1 años. Las crisis secundariamente generalizadas constituyen el tipo predominante (81,3%), la etiologia mas frecuente es la esclerosis mesial temporal (48,3%) y la mayoria de los pacientes presentaba examenes neurologicos normales y valoraciones neuro­psicologicas normales o bajas. Alrededor de la mitad (48,8%) de los pacientes habia sido medicada con un rango de 4-6 farmacos antiepilepticos, y los mas prescritos fueron lamotrigina, carbamacepina, acido valproico y fenitoina. Las principales recomendaciones en estos pacientes fueron: optimizacion de tratamiento, neurocirugia y reingreso. Se observan diferencias entre la edad de inicio y el sexo, la frecuencia de las crisis y el sexo, el tiempo de evolucion de la patologia y la cantidad de tratamientos fallidos, y el tiempo de evolucion de la enfermedad y la ocupacion. Conclusiones. Las caracteristicas sociodemograficas, el manejo de los pacientes, los farmacos antiepilepticos utilizados y las diferencias encontradas son similares a las descritas en otras latitudes.

  14. Mapping of soil-sediment systems contaminations around a metal-ore smelter. The example of Cu in Lubumbashi (RD Congo).

    NASA Astrophysics Data System (ADS)

    Mpundu, M.; Mukobo, R. P.; Kaya, D.; Faucon, M. P.; Andres, L.; Ngongo, M.; Meerts, P. J.; Colinet, G.

    2009-04-01

    The Katanga is famous for its high richness in metal ores, mainly Cu- and Co-minerals. The ore treatments activities lead to metal spreading in the environment which do endanger the viability of ecosystems and human health. The contaminations of soils and sediments around the Gecamines smelter in Lubumbashi have been evaluated through a multi-scale approach. In the first stage, a reference system about the natural contents in soils has been implemented. The main units of the detailed (1:20 000) soil map have been characterized through field observations and laboratory determinations : acido-basic and organic status, particle size distribution, cationic exchange capacity, total contents in Al, Fe, Mn, Cu, Co, Cd, Pb, Zn. An exploratory mapping of soil contaminations (Cu, Co, Cd, Pb, Zn) centered on the Gecamines cheminey was then conducted as a second stage of the approach. Detailed investigations were finally performed in the Gecamines district where signs of soil degradation were the highest. The spatial continuity and the differenciation (C : C0+C ratio) of the studied parameters appeared weak. No clear effect of the dominant wind direction on the spatial distribution of the contaminants could be identified despite a clear degradation of the ecosystem in the area under dominant wind. However the detailed approach showed evidences of (i) significant wind deposits in the Gecamines district, (ii) and local man-made deposits but also (ii) important processes of redistribution in the landscape through erosion/sedimentation or anthropic activities. Our results point out the difficulty to identify the sources of contaminations in an urban environment and stress the need to have approaches with complementary levels of details.

  15. [Control of epilepsy in adult patients with tuberous sclerosis].

    PubMed

    Gallardo-Tur, Alejandro; García-Martín, Guillermina; Chamorro-Muñoz, María Isabel; Romero-Godoy, Jorge; Romero-Acebal, Manuel

    2013-06-01

    Introduccion. La esclerosis tuberosa es una enfermedad genetica cuyas manifestaciones principales son la formacion de tumores neuroectodermicos, que asocia epilepsia secundaria muy frecuentemente. Objetivo. Describir el perfil epileptico, el control, la frecuencia de crisis y la efectividad del tratamiento en pacientes adultos con esclerosis tuberosa. Pacientes y metodos. Estudio descriptivo en el que se han incluido pacientes adultos (mayores de 14 anos) con diagnostico confirmado de esclerosis tuberosa. Se ha analizado la frecuencia y tipos de crisis. Se ha realizado un estudio y contabilizacion de los diferentes farmacos antiepilepticos en cada paciente, la frecuencia de uso de cada principio activo y un estudio comparativo entre control de crisis y tipo de terapia. Resultados. De 19 adultos estudiados, tuvieron crisis epilepticas 16 (84%). Presentaron control de crisis completo, crisis esporadicas y crisis frecuentes el 44%, 25% y 31%, respectivamente. Hubo frecuencia de crisis focales, generalizadas y ambas en el 38%, 6% y 25%, respectivamente. Estaban en tratamiento con farmacos antiepilepticos en monoterapia, biterapia y triterapia el 38%, 44% y 19%, respectivamente. El mas consumido globalmente fue el levetiracetam, seguido de la carbamacepina y el acido valproico. En monoterapia, el mas frecuente fue la carbamacepina, con mayor proporcion de control completo. Conclusiones. La epilepsia en la esclerosis tuberosa es relativamente benigna, y se consigue un aceptable control en la mayoria de casos con un numero de antiepilepticos acorde con lo aconsejado en las guias de tratamiento. Se observa estabilidad de lesiones, y no hay malignizacion en nuestra serie. El bajo numero de la muestra limita el estudio, pero se observan proporciones similares de efectividad del tratamiento respecto a otra serie publicada.

  16. 13,16-Dimethyl octacosanedioic acid (iso-diabolic acid), a common membrane-spanning lipid of Acidobacteria subdivisions 1 and 3.

    PubMed

    Damsté, Jaap S Sinninghe; Rijpstra, W Irene C; Hopmans, Ellen C; Weijers, Johan W H; Foesel, Bärbel U; Overmann, Jörg; Dedysh, Svetlana N

    2011-06-01

    The distribution of membrane lipids of 17 different strains representing 13 species of subdivisions 1 and 3 of the phylum Acidobacteria, a highly diverse phylum of the Bacteria, were examined by hydrolysis and gas chromatography-mass spectrometry (MS) and by high-performance liquid chromatography-MS of intact polar lipids. Upon both acid and base hydrolyses of total cell material, the uncommon membrane-spanning lipid 13,16-dimethyl octacosanedioic acid (iso-diabolic acid) was released in substantial amounts (22 to 43% of the total fatty acids) from all of the acidobacteria studied. This lipid has previously been encountered only in thermophilic Thermoanaerobacter species but bears a structural resemblance to the alkyl chains of bacterial glycerol dialkyl glycerol tetraethers (GDGTs) that occur ubiquitously in peat and soil and are suspected to be produced by acidobacteria. As reported previously, most species also contained iso-C(15) and C(16:1ω7C) as major fatty acids but the presence of iso-diabolic acid was unnoticed in previous studies, most probably because the complex lipid that contained this moiety was not extractable from the cells; it could only be released by hydrolysis. Direct analysis of intact polar lipids in the Bligh-Dyer extract of three acidobacterial strains, indeed, did not reveal any membrane-spanning lipids containing iso-diabolic acid. In 3 of the 17 strains, ether-bound iso-diabolic acid was detected after hydrolysis of the cells, including one branched GDGT containing iso-diabolic acid-derived alkyl chains. Since the GDGT distribution in soils is much more complex, branched GDGTs in soil likely also originate from other (acido)bacteria capable of biosynthesizing these components.

  17. Potential for using isotopically altered metalloproteins in species-specific isotope dilution analysis of proteins by HPLC coupled to inductively coupled plasma mass spectrometry.

    PubMed

    Harrington, Chris F; Vidler, Daniel S; Watts, Michael J; Hall, John F

    2005-07-01

    The production and evaluation of an isotopically enriched metalloprotein standard for use as a calibrant in species-specific isotope dilution analysis by HPLC coupled to inductively coupled plasma mass spectrometry is described. Using a model system involving the copper-containing protein rusticyanin (Rc) from the bacterium Acido-thiobacillus ferrooxidans, it was possible to demonstrate the analytical conditions that could be used for the measurement of metalloproteins by on-line IDMS analysis. Rc was chosen because it is a well-characterized protein with an established amino acid sequence and can be produced in suitable quantities using a bacterial recombinant system. Three different forms of the protein were studied by organic and inorganic mass spectrometry: the native form of the protein containing a natural isotopic profile for copper, an isotopically enriched species containing virtually all of its copper as the 65Cu isotope, and the nonmetalated apo form. Incorporation of the copper isotopes into the apo form of the protein was determined using a UV-vis spectrophotometric assay and shown to be complete for each of the copper-containing species. The experimental conditions required to maintain the conformational form of the protein with a nonexchangeable copper center were established using +ve electrospray mass spectrometry. A pH 7.0 buffer was found to afford the most appropriate conditions, and this was then used with HPLC-ICP-MS to verify the stability of the copper center by analysis of mixtures of different isotopic solutions. No exchange of the enriched copper isotope from Rc with an added naturally abundant inorganic copper cation was observed under a neutral pH environment, indicating that species-specific ID-MS analysis of metalloproteins is possible.

  18. [Electrical status epilepticus during sleep: a retrospective multi-centre study of 29 cases].

    PubMed

    Lorenzo-Ruiz, María; Miguel-Martin, Beatriz; García-Pérez, Asunción; Martínez-Granero, Miguel A; Aguilera-Albesa, Sergio; Yoldi-Petri, M Eugenia; Sánchez-Ruiz de Gordoa, Javier; Castro-De Castro, Pedro; Sánchez-Carpintero, Rocío

    2015-02-01

    Introduccion. El estado epileptico electrico durante el sueño (ESES) es un sindrome epileptico caracterizado por la presencia de descargas epilepticas tipo punta-onda lenta de manera muy persistente durante el sueño no REM. En la actualidad, el manejo de esta patologia es heterogeneo y no hay estudios controlados con los tratamientos utilizados, ni se ha comprobado si estos mejoran la evolucion cognitiva de los pacientes. Pacientes y metodos. Se revisan los pacientes diagnosticados de ESES durante 15 años en cuatro centros hospitalarios, se recoge la presentacion clinica, el manejo terapeutico y la evolucion clinica, y se compara con la bibliografia. Resultados. Se seleccionaron 29 pacientes con ESES, 20 de ellos idiopatico y 26 de ellos generalizado. Los farmacos con los que se consiguio mayor control de la actividad electrica fueron los corticoides/hormona adrenocorticotropa (ACTH), el clobazam y el levetiracetam. La mediana de duracion del ESES en los casos primarios fue de seis meses, y en los secundarios, el doble. El 45% de los pacientes mantuvo un cociente intelectual normal y un 40% presento en la evolucion discapacidad cognitiva de diferente grado. Conclusiones. El pronostico neuropsicologico evolutivo suele ser desfavorable y la evolucion cognitiva parece estar en relacion con la duracion del ESES y el area donde este concentrada la actividad epileptica, lo que sugiere que el mal pronostico, si se trata precozmente, se puede evitar. Los antiepilepticos mas frecuentemente utilizados son el acido valproico, la etosuximida y el levetiracetam, y en nuestra muestra tambien se utilizaron con frecuencia el clobazam y la lamotrigina. Los farmacos mas eficaces para el control del ESES fueron los corticoides/ACTH, el clobazam y el levetiracetam.

  19. [The prevalence of obesity and metabolic syndrome in paediatric patients with epilepsy treated in monotherapy with valproic acid].

    PubMed

    Carmona-Vazquez, C R; Ruiz-Garcia, M; Pena-Landin, D M; Diaz-Garcia, L; Greenawalt, S R

    2015-09-01

    Introduccion. El acido valproico (VPA) es un antiepileptico util para controlar diferentes tipos de epilepsia. Tiene efectos colaterales y se asocia a incremento del peso corporal y a alteraciones metabolicas y endocrinas, entre ellas sindrome metabolico. Objetivo. Conocer la prevalencia de la obesidad y el sindrome metabolico en pacientes pediatricos con epilepsia tratados en monoterapia con VPA. Pacientes y metodos. Estudio transversal, observacional, analitico. Se estudiaron pacientes tratados con VPA entre 2010-2014, y se midio el indice de masa corporal (IMC), el perimetro abdominal, la presion arterial, la glucosa, los trigliceridos y las lipoproteinas de alta densidad (HDL), en busqueda de obesidad y sindrome metabolico. La obesidad se definio con un IMC mayor del percentil 95; el sindrome metabolico, con al menos tres de los siguientes criterios: perimetro abdominal mayor del percentil 90, presion arterial sistemica mayor del percentil 90, trigliceridos mayores de 110 mg/dL y HDL menor de 40 mg/dL. Resultados. Se estudiaron 47 pacientes con una edad media de 10,1 ± 4 años; el 51,06% eran varones. Ocho (17%) desarrollaron obesidad y, de ellos, dos (25%), sindrome metabolico. Tres pacientes desarrollaron sobrepeso (6%). Observamos diferencias estadisticamente significativas de media de edad comparados con los grupos de IMC, donde los pacientes obesos eran adolescentes (ANOVA; p = 0,0001), y aquellos que tomaban mas VPA al dia eran los obesos (ANOVA; p = 0,024). Conclusiones. Los pacientes tratados con VPA que se convierten en obesos pueden desarrollar sindrome metabolico. Requieren una monitorizacion cuidadosa y, ante la presencia de ganancia de peso, se debera valorar la retirada del farmaco.

  20. Tuberculose pulmonaire à Brazzaville en hospitalisation pneumologique: impact du diagnostic tardif à l’infection au VIH sur les anomalies radiographiques

    PubMed Central

    Bemba, Esthel Lee Presley; Bopaka, Régis Gothard; Moyikoua, Régis; Ossibi-Ibara, Rolland; Ebenga-Somboko, Norela Bibiane; Toungou, Syn Nerval; Matondot, Paunel God’hervé; Ossale-Abacka, Boris Kevin; Okemba-Okombi, Franck Hardain; Mboussa, Joseph

    2016-01-01

    L’objectif de notre étude était de décrire les différents aspects radiographiques de la tuberculose pulmonaire selon le degré de l’immunodépression chez les patients VIH. Nous rapportons une étude rétrospective de 80 patients VIH positif non traités présentant une tuberculose pulmonaire, hospitalisés dans le service de Pneumo-phtisiologie de Brazzaville de Janvier 2013 à Janvier 2014. Notre échantillon était composé de 44 femmes (55%) et 36 hommes (45%) soit un sex ratio de 0,81. La moyenne d’âge était de 37,5±9,17ans, la moyenne du Taux de CD4 était de 153,13±86,6cell/mm3. La microscopie des expectorations à la recherche des bacilles acido-alcoolo-résistants était positive dans 75% des cas chez les patients ayant un taux de lymphocytes T CD4>200cell/ mm3. Les adénopathies médiastinales, les atteintes moyennes, inferieures du champ pulmonaire et la miliaire étaient plus fréquentes chez les patients ayant un taux de lymphocytes T CD4< 200cell/ mm3. L’immunodépression sévère est significativement associée à la présentation radiographique atypique de la tuberculose. PMID:27800112

  1. [Use of sodium acetate in feed rations in ketotic cows].

    PubMed

    Vojtísek, B; Hamrík, J; Hronová, B; Diblíková, I; Minksová, E

    1989-10-01

    On a farm where the ration of cows contained 88.0 g of butyric acid, an experimental group of cows (n = 8), producing milk containing 7.9 mg or more acetone per litre, was studied for 14 days for the effect of a 250 g supplement of sodium acetate to the ration (combined with single i.m. administration of vitamins A, D2 and E) on selected metabolism parameters and on milk production. As distinct from the control group of cows (n = 8) from the same farm which produced milk containing 3.9 mg or less acetone per litre and which were fed without sodium acetone supplements, a tendency of increased alkaemia of the organism was suggested in the experimental cows. This tendency manifested itself during the trial in increased pH values, increased base excess (BE) and standard bicarbonate (SB) in the blood, and in an increase in the pH value and net acido basic secretion in urine. A decrease was recorded in the concentration of the acetone + acetacetic acid sum, the same as beta-hydroxybutyric acid in blood and the sum of acetone and acetacetic acid in milk (P less than 0.01). An insignificant increase of the activity of gammaglutamyl transpeptidase (GMT) was recorded in the blood serum of the experimental cows and a significant increase occurred in the content of potassium (up to P less than 0.01) and urea (up to P less than 0.01) in urine. The supplement of sodium acetate to the feed ration did not influence the degree of ketonuria and the finding of urobilinogen in urine.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. [Mango: agroindustrial aspects, nutritional/functional value and health effects].

    PubMed

    Wall-Medrano, Abraham; Olivas-Aguirre, Francisco J; Velderrain-Rodriguez, Gustavo R; González-Aguilar, A; de la Rosa, Laura A; López-Díaz, Jose A; Álvarez-Parrilla, Emilio

    2014-11-01

    Objetivo: Revisar y discutir la información más reciente sobre el valor agroindustrial, funcional y nutricional de uno de los frutos de mayor cultivo, exportación y consumo en México: el Mango. Métodos: Se realizó una búsqueda en diversas bases de datos (PubMed, Cochrane, ScienceDirect) y documentos de libre acceso (Google Scholar) sobre Mangifera indica L. Esta información fue posteriormente sub-clasificada en aspectos agroindustriales, nutricionales, funcionales y efectos a la salud. Resultados: Uno de cada veinte mangos consumidos mundialmente, es mexicano. “Ataulfo” es la variedad la de mayor importancia agronómica. El procesamiento mínimo de su pulpa (MP) genera residuos de cáscara (MC) y semilla con alto potencial nutracéutico. MP y MC son buenas fuentes de ascorbato, fructosa, fibra dietarias soluble (MP, almidones y ramnogalacturonanos) e insoluble (MC, ligninas y hemicelulosa) y lípidos funcionales (MP). MP y MC poseen un perfil de compuestos fenólicos (CF) monoméricos (MP) como el acido gálico y el protocatehuico y poliméricos (MC) como la -PGG asociados con efectos anti-obesigénicos, anti-inflamatorios, anti-cancerigenos y anti-diabeticos. Estos beneficios son dependientes de la bioaccesibilidad (liberación de su matriz alimentaria) y destino metabólico (biodisponibilidad) de estos CF. Discusión: El mango resulta una valiosa fuente de compuestos antioxidantes con comprobado beneficio a la salud. Sin embargo, factores como la variedad, temporalidad de cultivos, tratamientos pre y post-cosecha, extracción de bioactivos y algunas barreras fisiológicas pueden modificar su potencial nutracéutico.

  3. [Prevalence, type of epilepsy and use of antiepileptic drugs in primary care].

    PubMed

    Fernández-Suárez, Elena; Villa-Estébanez, Rubén; Garcia-Martinez, Alberto; Fidalgo-González, José A; Zanabili Al-Sibbai, Ahmad A; Salas-Puig, Javier

    2015-06-16

    Introduccion. La epilepsia es una enfermedad con gran repercusion social y economica. La prevalencia deberia ser usada como la base mas importante para planificar la prevencion secundaria y terciaria. Objetivos. Identificar los pacientes con diagnostico de epilepsia en un centro de atencion primaria y determinar la prevalencia, las caracteristicas demograficas, el tipo de sindrome epileptico y el uso de los farmacos antiepilepticos. Pacientes y metodos. Estudio descriptivo transversal retrospectivo. Incluyo 196 pacientes con diagnostico de epilepsia pertenecientes a un centro de salud y revision de la historia clinica hospitalaria, con el estudio de las variables sociodemograficas y clinicofarmacologicas. Resultados. Prevalencia de epilepsia: 8,4/1.000 habitantes. Edad media: 50,3 años. Sexo: 52,6%, hombres. Ambito: 79,6%, urbano. Antecedentes familiares de epilepsia: 14,8%. Tipo de epilepsia: focal sintomatica por ictus (14,3%), generalizada idiopatica (13,8%), focal criptogenica (8,7%), no clasificada (31,1%). Edad media al inicio de la crisis: 31,6 años. Comorbilidad neurologica o psiquiatrica: 62,8%. Ultima revision: el 18,9% sin tratamiento antiepileptico, el 56,6% en monoterapia y el 24,5% en politerapia. Libres de crisis: 76,5%. Farmacos mas prescritos: acido valproico, carbamacepina, fenitoina, lamotrigina y levetiracetam. Un 78,6% sin efectos secundarios. Fallecimiento: 4,1%. Conclusiones. La prevalencia de pacientes con epilepsia fue de 8,4/1.000 habitantes y predomina la focal sintomatica por ictus. Casi un tercio de los pacientes referia algun factor desencadenante de crisis, principalmente consumo de alcohol o fiebre. Predomina la monoterapia, los efectos secundarios son escasos y, en la ultima revision, la mayoria se hallaba libre de crisis.

  4. Is surgery always the best treatment for severe carotid stenosis in the frail elderly?

    PubMed

    Quarto, Gennaro; Benassai, Giacomo; Gallinoro, Emanuele; Amato, Bruno; Furino, Ermenegildo

    2015-01-01

    Lo stroke è la terza causa di morte nel mondo occidentale dopo l’infarto del miocardio ed il cancro, con il 10-12% di tutti i decessi; l’eziologia ischemica riveste un ruolo preponderante (il 25% è su base embolica), per cui la stenosi aterosclerotica carotidea rappresenta un fattore di rischio. Lo studio NASCET ha provato l’utilità della chirurgia nel trattamento di tale patologia, tuttavia sotto precisi criteri di selezione. Il seguente caso riguarda un paziente affetto da stenosi carotidea che, pur rientrando nei criteri emodinamici di operabilità (percentuale e velocità di flusso), in considerazione delle comorbidità presenti alla diagnosi, non è stato possibile sottoporre a intervento di Trombo-Endo-Arteriectomia (TEA). Il paziente che si era affidato a noi si presentava completamente asintomatico e ciò è stato confermato anche dalla TC cerebrale cui è stato sottoposto dopo la diagnosi di stenosi. Considerando che la neoplasia del paziente, al momento della diagnosi, era al III stadio e che tale staging consente un tasso di sopravvivenza a 5 anni inferiore al 50% e che la TEA non è esente dal rischio di re-stenosi, si è ritenuto che tale procedura non poteva migliorare la prognosi del paziente. L’alternativa presa in considerazione, quindi, è stata l’angioplastica con stent. Tuttavia, se si valuta la non trascurabile possibilità di una recidiva locale della neoplasia, non si può escludere l’utilità di un ulteriore ciclo di radioterapia, con il rischio che questa possa determinare una stenosi in-stent, essendo, la neoplasia omolaterale alla stenosi da trattare. Per questi motivi è stata adottata una terapia conservativa con doppia antiaggregazione (Clopidogrel + Acido Acetil Salicilico). A 8 mesi, il paziente non ha sviluppato accidenti neuro-vascolari.

  5. pH as a Driver for Ammonia-Oxidizing Archaea in Forest Soils.

    PubMed

    Stempfhuber, Barbara; Engel, Marion; Fischer, Doreen; Neskovic-Prit, Ganna; Wubet, Tesfaye; Schöning, Ingo; Gubry-Rangin, Cécile; Kublik, Susanne; Schloter-Hai, Brigitte; Rattei, Thomas; Welzl, Gerhard; Nicol, Graeme W; Schrumpf, Marion; Buscot, Francois; Prosser, James I; Schloter, Michael

    2015-05-01

    In this study, we investigated the impact of soil pH on the diversity and abundance of archaeal ammonia oxidizers in 27 different forest soils across Germany. DNA was extracted from topsoil samples, the amoA gene, encoding ammonia monooxygenase, was amplified; and the amplicons were sequenced using a 454-based pyrosequencing approach. As expected, the ratio of archaeal (AOA) to bacterial (AOB) ammonia oxidizers' amoA genes increased sharply with decreasing soil pH. The diversity of AOA differed significantly between sites with ultra-acidic soil pH (<3.5) and sites with higher pH values. The major OTUs from soil samples with low pH could be detected at each site with a soil pH <3.5 but not at sites with pH >4.5, regardless of geographic position and vegetation. These OTUs could be related to the Nitrosotalea group 1.1 and the Nitrososphaera subcluster 7.2, respectively, and showed significant similarities to OTUs described from other acidic environments. Conversely, none of the major OTUs typical of sites with a soil pH >4.6 could be found in the ultra- and extreme acidic soils. Based on a comparison with the amoA gene sequence data from a previous study performed on agricultural soils, we could clearly show that the development of AOA communities in soils with ultra-acidic pH (<3.5) is mainly triggered by soil pH and is not influenced significantly by the type of land use, the soil type, or the geographic position of the site, which was observed for sites with acido-neutral soil pH.

  6. Cardiovascular risk factors in children and adolescents with anxiety disorders and their association with disease severity.

    PubMed

    Cheuiche Pires, Gabriela; Camboim Rockett, Fernanda; Abrahão Salum Júnior, Giovanni; Gus Manfro, Gisele; Bosa, Vera Lúcia

    2005-01-01

    Introducción: Evidencias sugieren que la ansiedad es una prediciente independiente de los eventos cardiovasculares adversos. Entretanto, pocos estudios evaluaron la presencia de factores de riesgo (FR) para estas enfermedades en ninos y adolescentes. Objetivos: Identificar la prevalencia de FR cardiovasculares en ninos y adolescentes diagnosticados con disturbio de ansiedad y su asociacion con la gravedad de la enfermedad. Metodología: Estudio transversal que avaluo FR nutricional, antropometricos, % de gordura corporal (CG), presion arterial (PA), nivel de actividad fisica y escalas de sintomas y gravedad de la ansiedad. Resultados: 65 ninos y adolescentes (8.6 } 1.7 anos) fueron incluidos en el estudio. Cuanto a los FR, el consumo excesivo de acidos grasos saturados (52.3%), indice de masa corporal alto (50.8%), PA alterada (50.8%) y la falta de ejercicio fisico (50.0%) fueron los mas prevalecientes. Hubo asociacion significativa entre la mayor gravedad del disturbio y el acumulo de ≥ 6 FR (p=0,026), exceso de gordura abdominal medida por la circunferencia de cintura (p=0.019) y por el indice de conicidad (p=0.053) y exceso en el % GC (p=0.044). Conclusión: Los resultados encontrados indican que hay una alta prevalencia de FR cardiovascular en la amuestra estudiada y los pacientes mas graves presentaron mayor riesgo. La caracterizacion del perfil de riesgo en las poblaciones con predisposicion a las enfermedades cardiovasculares es crucial para la elaboracion de estrategias de intervencion que oportunicen la reduccion en la prevalencia de estas enfermedades.

  7. Tuberculosis diagnostics in Fiji: how reliable is culture?

    PubMed

    Reddy, M; Gounder, S; Reid, S A

    2014-09-21

    Contexte : L'examen microscopique de crachats à la recherche de bacilles acido-alcoolo résistants (AFB) et la culture de Mycobacterium tuberculosis sont des examens de première intention dans le diagnostic de la tuberculose (TB). La contamination des cultures de TB réduit la fiabilité du diagnostic.Objectif: Examiner les facteurs associés à la contamination des cultures de TB aux Fidji et les performances relatives de la culture et de l'AFB.Méthodes : Tous les examens réalisés au Laboratoire de Référence des Mycobacterium de Daulakao aux Fidji de 2010 à 2012 ont été inclus. Les variables comprenaient les résultats de l'AFB et de la culture, l'âge et le type de spécimen, le centre d'examen ayant envoyé l'échantillon et l'âge du patient.Résultats: Des 5708 spécimens enregistrés, 70% comprenaient à la fois les résultats du frottis AFB et de la culture. Une contamination est survenue dans 421 spécimens et 2,7% d'entre eux étaient soit dégradés, soit sans résultats. L'accord entre les deux tests était modéré (κ = 0,577). La culture avait plus de chances d'être positive quand le score du frottis AFB était plus élevé. La contamination de la culture était associée à la distance par rapport au laboratoire de référence, à l'âge de l'échantillon et à des facteurs liés à l'opérateur.Conclusion : Une plus grande rapidité de transmission des échantillons de crachats depuis le centre d'examens anti-tuberculeux ou l'adjonction de conservateurs aux spécimens de crachats pourrait amener une diminution du taux de contamination des cultures. L'introduction de techniques de cultures liquides combinée à la culture sur milieu Ogawa augmentera la sensibilité du diagnostic de la TB aux Fidji.

  8. The role of extremophile in the redox reaction of Fe and As relating with the formation of secondary phase mineral in extreme environment, Norris Geyser Basin, Yellowstone National Park, USA

    NASA Astrophysics Data System (ADS)

    Koo, T. H.; Kim, J. Y.; Park, K. R.; Jung, D. H.; Geesey, G. G.; Kim, J. W.

    2015-12-01

    Redox reaction associated with microbial elemental respiration is a ubiquitous process in sediments and suspended particles at various temperatures or pH/Eh conditions. Particularly, changes in elemental redox states (structural or dissolved elemental form) induced by microbial respiration result in the unexpected biogeochemical reactions in the light of biotic/abiotic mineralization. The objective of the present study is, therefore to investigate the secondary phase mineralization through a-/biogeochemical Fe and As redox cycling in the acido-hyperhtermal Norris Geyser Basin (NGB) in Yellowstone National Park, USA, typical of the extreme condition. X-ray diffraction, scanning electron microscope with energy dispersive x-ray spectroscopy, X-ray absorption near edge structure, inductively coupled plasma-atomic emission spectrometer and liquid chromatography with ICP-mass spectroscopy with filtrated supernatant were performed for the mineralogical and hydro-geochemical analysis. The clay slurry collected from the active hot-spring of the NGB area (pH=3.5 and Temperature=78 ℃) was incubated with ("enrichment") or without the growth medium ("natural"). The control was prepared in the same condition except adding the glutaraldehyde to eliminate the microbial activity. The secondary phase mineral formation of the oxidative phase of Fe and As, and K identified as 'Pharmacosiderite' only appeared in the enrichment set suggesting a role of extremophiles in the mineral formation. The considerable population of Fe-oxidizer (Metallosphera yellowstonensis MK-1) and As-oxidizer (Sulfurihydrogenibium sp.) was measured by phylogenetic analysis in the present study area. The inhibition of As-oxidation in the low pH conditions was reported in the previous study, however the As-redox reaction was observed and consequently, precipitated the Pharmacosiderite only in the enrichment set suggesting a biotic mineralization. The present study collectively suggests that the microbial

  9. Peak shapes of acids and bases under overloaded conditions in reversed-phase liquid chromatography, with weakly buffered mobile phases of various pH: a thermodynamic interpretation.

    PubMed

    Gritti, Fabrice; Guiochon, Georges

    2009-01-01

    We measured overloaded band profiles for a series of nine compounds (phenol, caffeine, 3-phenyl 1-propanol, 2-phenylbutyric acid, amphetamine, aniline, benzylamine, p-toluidine, and procainamidium chloride) on columns packed with four different C(18)-bonded packing materials: XTerra-C(18), Gemini-C(18), Luna-C(18)(2), and Halo-C(18), using buffered methanol-water mobile phases. The pHWS of the mobile phase was increased from 2.6 to 11.3. The buffer concentration (either phosphate, acetate, or carbonate buffers) was set constant at values below the maximum concentration of the sample in the band. The influence of the surface chemistry of the packing material on the retention and the shape of the peaks was investigated. Adsorbents having a hybrid inorganic/organic structure tend to give peaks exhibiting moderate or little tailing. The retention and the shape of the band profiles can easily be interpreted at pHsWS that are well above or well below the pKWS(a) of the compound studied. In contrast, the peak shapes in the intermediary pH range (i.e., close to the compound pKWS(a)) have rarely been studied. These shapes reveal the complexity of the competitive adsorption behavior of couples of acido-basic conjugated compounds at pHsWS that are close to their pKWS(a). They also reveal the role of the buffer capacity on the resulting peak shape. With increasing pHWS, the overloaded profiles are first langmuirian (isotherm type I) at low pHsWS, they become S-shaped (isotherm type II), then anti-langmuirian (isotherm type III), S-shaped again at intermediate pHsWS, and finally return to a langmuirian shape at high pHsWS. A new general adsorption isotherm model that takes into account the dissociation equilibrium of conjugated acidic and basic species in the bulk mobile phase accounts for these transient band shapes. An excellent agreement was achieved between experimental profiles and those calculated with a two-sites adsorption isotherm model at all pHsWS. The neutral

  10. Using short-lived nuclides of the U- and Th-series to probe the kinetics of colloid migration in forested soils

    NASA Astrophysics Data System (ADS)

    Rihs, Sophie; Prunier, Jonathan; Thien, Bruno; Lemarchand, Damien; Pierret, Marie-Claire; Chabaux, François

    2011-12-01

    The recent chemical dynamics of a podzolic forest soil section (from the Strengbach watershed, France) was investigated using U- and Th-series nuclides. Analyses of ( 238U), ( 230Th), ( 226Ra), ( 232Th), ( 228Ra) and ( 228Th) activities in the soil particles, the seepage waters, and the mature leaves of the beech trees growing on this soil were performed by TIMS or gamma spectrometry. The simultaneous analysis of the different soil ( sl) compartments allows to demonstrate that a preferential Th leaching over Ra must be assumed to explain the ( 226Ra/ 230Th), ( 228Ra/ 232Th) and ( 228Th/ 228Ra) disequilibria recorded in the soil particles. The overall Ra- and Th- transfer schemes are entirely consistent with the prevailing acido-complexolysis weathering mechanism in podzols. Using a continuous open-system leaching model, the ( 226Ra/ 230Th) and ( 228Ra/ 232Th) disequilibria measured in the different soil layers enable dating of the contemporary processes occurring in this soil. In this way, we have determined that a preferential Th-leaching from the shallow Ah horizon, due to a strong complexation with organic colloids, began fairly recently (18 years ago at most). The continual increase in pH recorded in precipitations over the last 20 years is assumed to be the cause of this enhanced organic complexation. A lower soil horizon (50-60 cm) is also affected by preferential Th leaching, though lasting over several centuries at least, with a much smaller leaching rate. The migration of Th isotopes through this soil section might hence be used as a tracer for the organic colloids migration and the induced radioactive disequilibria demonstrate to be useful for assessing the colloidal migration kinetics in a forested soil. Ra and Th isotopic ratios also appear to be valuable tracers of some mineral-water-plant interactions occurring in soil. The ( 228Ra/ 226Ra) ratio enables discrimination of the Ra flux originating from leaf degradation from that originating from mineral

  11. Overloaded elution band profiles of ionizable compounds in reversed-phase liquid chromatography: Influence of the competition between the neutral and the ionic species

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2008-01-01

    The parameters that affect the shape of the band profiles of acido-basic compounds under moderately overloaded conditions (sample size less than 500 nmol for a conventional column) in RPLC are discussed. Only analytes that have a single pK{sub a} are considered. In the buffer mobile phase used for their elution, their dissociation may, under certain conditions, cause a significant pH perturbation during the passage of the band. Two consecutive injections (3.3 and 10 {micro}L) of each one of three sample solutions (0.5, 5, and 50 mM) of ten compounds were injected on five C{sub 18}-bonded packing materials, including the 5 {micro}m Xterra-C{sub 18} (121 {angstrom}), 5 {micro}m Gemini-C{sub 18} (110 {angstrom}), 5 {micro}m Luna-C{sub 18}(2) (93 {angstrom}), 3.5 {micro}m Extend-C{sub 18} (80 {angstrom}), and 2.7 {micro}m Halo-C{sub 18} (90 {angstrom}). The mobile phase was an aqueous solution of methanol buffered at a constant {sub W}{sup W}pH of 6, with a phosphate buffer. The total concentration of the phosphate groups was constant at 50 mM. The methanol concentration was adjusted to keep all the retention factors between 1 and 10. The compounds injected were phenol, caffeine, 3-phenyl 1-propanol, 2-phenyl butyric acid, amphetamine, aniline, benzylamine, p-toluidine, procainamidium chloride, and propranololium chloride. Depending on the relative values of the analyte pK{sub a} and the buffer solution pH, these analytes elute as the neutral, the cationic, or the anionic species. The influence of structural parameters such as the charge, the size, and the hydrophobicity of the analytes on the shape of its overloaded band profile is discussed. Simple but general rules predict these shapes. An original adsorption model is proposed that accounts for the unusual peak shapes observed when the analyte is partially dissociated in the buffer solution during its elution.

  12. Arthrite à pneumocoque chez un adulte immunocompétent

    PubMed Central

    Chemsi, Hicham; Chadli, Maryama; Sekhsokh, Yassine

    2015-01-01

    Les infections à pneumocoques sont avant tout respiratoires, ORL et méningées. Les infections ostéoarticulaires à pneumocoque ont la particularité de survenir dans moins de 20% des cas chez l'adulte sain. Habituellement, un ou plusieurs facteurs favorisants sont retrouvés. Toutefois, nous rapportons lors de cette observation le cas d'une arthrite à Streptococcus pneumoniae chez un adulte immunocompétent sans facteurs prédisposant. Patient âgé de 66 ans, diabétique de type II, a été hospitalisé pour une décompensation acido-cétosique et une monoarthrite du genou droit. Ce patient était fébrile (39°C) et présentait un genou droit inflammatoire en flexion avec rougeur et chaleur locale et un choc rotulien. Une ponction articulaire avec d'autres examens ont été réalisés pour confirmation d'une arthrite septique à pneumocoque. Le résultat de la ponction articulaire réalisée a montré un liquide jaune citron trouble avec 480 000 leucocytes/mm3 à prédominance polynucléaires neutrophiles. L'examen direct a montré des coccis à Gram positif en diplocoque, la culture a permis d'isoler un Streptococcus pneumoniae sensible à la pénicilline G. L’évolution clinique et biologique de l'arthrite du genou était favorable. Un déficit immunitaire, un asplénisme anatomique ou fonctionnel peuvent être en cause. L'alcoolisme est un facteur favorisant mais le mécanisme n'est pas clairement élucidé. La présence de matériel prothétique, peut favoriser une localisation septique. Ces facteurs de risque doivent être systématiquement recherchés, notamment en cas d'infection grave ou récidivante, une antibioprophylaxie ou une vaccination pouvant être proposées chez les sujets à haut risque. PMID:26327976

  13. Methanotrophic activity and bacterial diversity in volcanic-geothermal soils at Pantelleria island (Italy)

    NASA Astrophysics Data System (ADS)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-04-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic/geothermal soils are source of methane, but also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria island (Italy), Favara Grande, whose total methane emission was previously estimated in about 2.5 t a-1. Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values up to 950 ng g-1 dry soil h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile and the maximum methane consumption was measured in the top-soil layer but values > 100 ng g-1 h-1 were maintained up to a depth of 15 cm. The highest consumption rate was measured at 37 °C, but a still recognizable consumption at 80 °C (> 20 ng g-1 h-1) was recorded. In order to estimate the bacterial diversity, total soil DNA was extracted from Favara Grande and analysed using a Temporal Temperature Gradient gel Electrophoresis (TTGE) analysis of the amplified bacterial 16S rRNA gene. The three soil samples were probed by PCR using standard proteobacterial primers and newly designed verrucomicrobial primers targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected in sites FAV2 and FAV3, but not in FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site FAV2 pointed out a high diversity of gammaproteobacterial methanotrophs distantly related to Methylococcus/Methylothermus genera and the presence of the newly discovered acido-thermophilic methanotrophs

  14. DNA damage induced by a new 2-chloroethyl nitrosourea on malignant melanoma cells.

    PubMed

    Godeneche, D; Rapp, M; Thierry, A; Laval, F; Madelmont, J C; Chollet, P; Veyre, A

    1990-09-15

    Different biological aspects of a novel 2-chloroethyl nitrosourea derived from cysteamine, N'-(2-chloroethyl)-N-[2-(methylsulfinyl)ethyl]-N'- nitrosourea (CMSOEN2), were studied. Drug-induced cytotoxic effects, uptake kinetics, DNA damage, and O6-alkylguanine-DNA alkyltransferase activity were determined in 3 melanoma cell lines: the murine B16 and 2 human metastatic-derived cell lines (M4 Beu and M3 Dau). We found that radioactivity uptake and incorporation in acido-precipitable material was inversely proportional to cell drug viability. The highly CMSOEN2-sensitive B16 line showed the lowest total radioactivity uptake. In fact, among the melanoma cell parameters studied, 3 of them were well correlated: (a) cytotoxicity as reflected by the colony-forming assay; (b) DNA cross-link frequency estimated by the alkaline elution technique; and (c) O6-alkylguanine-DNA alkyltransferase activity (Mer phenotype), defined as the ability of cell extracts to remove O6-methylguanine from N-methyl-N-nitrosourea-alkylated DNA. The 2 human cell lines (M4 Beu and M3 Dau), the most resistant to the cytostatic drug effects, showed little or no ability to form DNA lethal cross-links. These results correspond to the higher O6-alkylguanine-DNA alkyltransferase activity found in human-derived cell lines compared with that present in murine B16 cell lines. This study confirms that the cell content in this repair DNA protein is certainly one of the important factors implicated in the variability of response to 2-chloroethyl nitrosourea treatment observed in a number of established malignant cell lines. It has been shown that pretreatment of derived cell lines with methylating agents (N-methyl-N-nitrosourea, N-methyl-N'-nitro-N-nitrosoguanidine) or O6-methylguanine used as a free base, increased cytotoxic effects of this class of anticancer agents, likely by saturating receptor sites (sulfhydryl groups) of this specific DNA repair enzyme. Nevertheless, in preliminary Phase I and II clinical

  15. Mucilaginibacter paludis gen. nov., sp. nov. and Mucilaginibacter gracilis sp. nov., pectin-, xylan- and laminarin-degrading members of the family Sphingobacteriaceae from acidic Sphagnum peat bog.

    PubMed

    Pankratov, Timofei A; Tindall, Brian J; Liesack, Werner; Dedysh, Svetlana N

    2007-10-01

    Two facultatively aerobic, heterotrophic bacteria capable of degrading pectin, xylan, laminarin and some other polysaccharides were obtained from the acidic Sphagnum peat bog Bakchar, in western Siberia, Russia, and were designated strains TPT18(T) and TPT56(T). Cells of these isolates are Gram-negative, non-motile, long rods that are covered by large capsules. On ageing, they transform into spherical L-forms. Strains TPT18(T) and TPT56(T) are acido- and psychrotolerant organisms capable of growth at pH 4.2-8.2 (with an optimum at pH 6.0-6.5) and at 2-33 degrees C (with an optimum at 20 degrees C). The major fatty acids are iso-C(15 : 0), anteiso-C(15 : 0), iso-C(17 : 0) 3-OH and summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c); the quinones are MK-7 and MK-6. Comparative 16S rRNA gene sequence analysis revealed that the novel strains share 97 % sequence similarity and belong to the family Sphingobacteriaceae; however, they are related only distantly to members of the genera Pedobacter (91.8-93.3 % similarity) and Sphingobacterium (89.6-91.2 % similarity). The DNA G+C content of strains TPT18(T) and TPT56(T) is 42.4 and 46.1 mol%, respectively. The low DNA-DNA hybridization value (42 %) and a number of phenotypic differences between strains TPT18(T) and TPT56(T) indicated that they represent two separate species. Since the two isolates are clearly distinct from all currently described members of the family Sphingobacteriaceae, we propose a novel genus, Mucilaginibacter gen. nov., containing two novel species, Mucilaginibacter gracilis sp. nov. and Mucilaginibacter paludis sp. nov. The type strains of Mucilaginibacter gracilis and Mucilaginibacter paludis are respectively TPT18(T) (=ATCC BAA-1391(T) =VKM B-2447(T)) and TPT56(T) (=ATCC BAA-1394(T) =VKM B-2446(T)).

  16. Superoxide reductase from Desulfoarculus baarsii: identification of protonation steps in the enzymatic mechanism.

    PubMed

    Nivière, Vincent; Asso, Marcel; Weill, Claire O; Lombard, Murielle; Guigliarelli, Bruno; Favaudon, Vincent; Houée-Levin, Chantal

    2004-01-27

    Superoxide reductase (SOR) is a metalloenzyme that catalyzes the reduction of O2*- to H2O2 and provides an antioxidant mechanism in some anaerobic and microaerophilic bacteria. Its active site contains an unusual mononuclear ferrous center (center II). Protonation processes are essential for the reaction catalyzed by SOR, since two protons are required for the formation of H2O2. We have investigated the acido-basic and pH dependence of the redox properties of the active site of SOR from Desulfoarculus baarsii, both in the absence and in the presence of O2*-. In the absence of O2*-, the reduction potential and the absorption spectrum of the iron center II exhibit a pH transition. This is consistent with the presence of a base (BH) in close proximity to the iron center which modulates its reduction properties. Studies of mutants of the closest charged residues to the iron center II (E47A and K48I) show that neither of these residues are the base responsible for the pH transitions. However, they both interact with this base and modulate its pKa value. By pulse radiolysis, we confirm that the reaction of SOR with O2*- involves two reaction intermediates that were characterized by their absorption spectra. The precise step of the catalytic cycle in which one protonation takes place was identified. The formation of the first reaction intermediate, from a bimolecular reaction of SOR with O2*-, does not involve proton transfer as a rate-limiting step, since the rate constant k1 does not vary between pH 5 and pH 9.5. On the other hand, the rate constant k2 for the formation of the second reaction intermediate is proportional to the H+ concentration in solution, suggesting that the proton arises directly from the solvent. In fact, BH, E47, and K48 have no role in this step. This is consistent with the first intermediate being an iron(III)-peroxo species and the second one being an iron(III)-hydroperoxo species. We propose that BH may be involved in the second protonation

  17. Rachianesthésie pour césarienne: facteurs de risque d'apparition de scores d'Apgar inférieur à 7 chez les nouveau-nés malgaches

    PubMed Central

    Rasolonjatovo, Tsiorintsoa Yvonne; Ravololonirina, Bako Minosoa Gilberthe; Randriamanantany, Zely Arivelo; Raveloson, Nasolotsiry Enintsoa

    2014-01-01

    Introduction La rachianesthésie est courante en obstétrique. L'hypotension artérielle maternelle apparaît dans 50-80%. Elle affecte l’équilibre acido-basique et l’état clinique du nouveau-né. Pour y remédier, l'usage de vasoconstricteurs est incontournable. L’éphédrine était de loin de premier choix en obstétrique. Dans les pays développés, elle est co-administrée avec la phényléphrine. A Madagascar, seule l’éphédrine reste disponible. Notre étude consiste à déterminer les facteurs de risque d'apparition du score d'Apgar inférieur à 7 chez les nouveau-nés. Méthodes Une étude rétrospective transversale, analytique, était effectuée à la Maternité de Befelatanana, Antananarivo Madagascar (Décembre 2010-Décembre 2011). Nous avons inclus 344 césariennes opérées sous rachianesthésie. Le critère principal de jugement était l'observation de score d'Apgar inférieur ou égal à 7 à la première minute. Les données étaient analysées sur logiciel Epi Info version 6.04 (IC à 95%, p bilatéral < 0.05). Résultats Le score d'Apgar était inférieur ou égal à 7 dans 42%. Les facteurs de risque retrouvés étaient la césarienne en urgence, la dose d’éphédrine dépassant 30mg ainsi que la baisse de la pression artérielle diastolique supérieure à 10% par rapport à sa valeur initiale (p respectif <<0.05). Conclusion La précarité de l’état clinique des nouveau-nés à la naissance est multifactorielle. La baisse de la pression artérielle diastolique associée à une dose élevée d’éphédrine est néfaste. De plus, l'augmentation de la catécholaminémie maternelle puis fœtale l'aggrave. PMID:25821536

  18. Evaluation of the implementation of the Xpert® MTB/RIF assay in Fiji.

    PubMed

    Gounder, A; Gounder, S; Reid, S A

    2014-09-21

    Contexte : Tous les tests Xpert® MTB/RIF réalisés dans les trois centres de traitement anti-tuberculeux aux Fidji entre juin 2012 et février 2013.Objectifs : Déterminer 1) le nombre de tests Xpert réalisés dans chaque centre, 2) l'association entre la qualité des crachats et le résultat du test Xpert, 3) l'accord entre Xpert et la microscopie des crachats acido alcoolo résistant (AFB) et la culture, et 4) le taux d'erreurs.Schéma : Revue rétrosp ective de dossiers.Résultats : Un total de 415 tests Xpert a été réalisé pendant la période d'étude. Mycobacterium tuberculosis a été détecté dans 69 (16.6%) échantillons. Aucune résistance à la rifampicine n'a été décelée. M. tuberculosis a été identifié dans 60 (18,7%) échantillons de crachats de bonne qualité. Un total de 43 (10,4%) erreurs sont survenues pendant la période d'étude. M. tuberculosis a été identifié dans 10 (2,9%) spécimens à frottis négatif. Il y a eu une concordance substantielle et presque parfaite entre les résultats du Xpert et ceux de la microscopie AFB (κ = 0,793) et de la culture (κ = 0,818), respectivement.Conclusion : En dépit de la bonne corrélation entre Xpert et les deux autres tests mise en évidence dans l'étude, Xpert ne peut toujours pas remplacer les tests de diagnostic de routine utilisés en première intention aux Fidji, en raison de contraintes logistiques et de problèmes de pérennité. Il est nécessaire de réaliser une évaluation ultérieure de la performance de ce test sur une période plus longue afin de mesurer sa valeur diagnostique dans la détection de cas à frottis négatif, Xpert positif aux Fidji.

  19. Prise en charge diagnostique et thérapeutique de la tuberculose ganglionnaire en Tunisie

    PubMed Central

    Ben Brahim, Hajer; Kooli, Ikbel; Aouam, Abir; Toumi, Adnene; Loussaief, Chawki; Koubaa, Jamel; Chakroun, Mohamed

    2014-01-01

    La tuberculose ganglionnaire est la localisation extra-pulmonaire la plus fréquente de la tuberculose. Nous nous proposons dans ce travail d’étudier les modalités diagnostiques, thérapeutiques et évolutives de cette localisation. Il s'agit d'une étude rétrospective portant sur 100 cas de tuberculose ganglionnaire. L’âge moyen était de 35 ± 15 ans (15-85 ans). Aucun malade n’était VIH positif. L'aire cervicale était la plus touchée (93 cas). L'intradermo-réaction à la tuberculine était positive dans 76/91 cas (83,5%). L'examen bactériologique des prélèvements au niveau des ganglions atteints avait mis en évidence des bacilles acido-alcoolo-résistants à l'examen direct dans 2/31 cas (6,4%) et la culture avait isolé Mycobacteruim tuberculosis dans 1/31 cas (3,2%). La cytoponction ganglionnaire (FNAC) était évocatrice de tuberculose dans 35/42 cas (83,3%). La biopsie ganglionnaire était réalisée dans 69 cas et avait permis de retenir le diagnostic de tuberculose dans tous les cas. La FNAC, comparativement à la biopsie, avait permis de raccourcir significativement le délai de la prise en charge (15,1 vs 22,8 jours; p=0,001) et la durée d'hospitalisation (17,3 vs 24,6; p=0,004). La durée moyenne du traitement antituberculeux était de 9,8 ± 4,6 mois (7 à 44 mois). Le traitement chirurgical initial avait raccourci significativement la durée du traitement médical. Il n'avait pas d'impact sur le taux de guérison. Nous avons noté 10 cas de réponse paradoxale aux antituberculeux, quatre cas de résistance clinique et une rechute dans deux cas. La tuberculose ganglionnaire pose un problème diagnostique et thérapeutique. La microbiologie est d'un faible apport. La FNAC est un moyen diagnostique très utiles dans les pays endémiques et à faibles ressources. Un traitement médical seul permet d’éviter les inconvénients de la chirurgie. PMID:25829976

  20. Methanotrophic activity and diversity of methanotrophs in volcanic geothermal soils at Pantelleria (Italy)

    NASA Astrophysics Data System (ADS)

    Gagliano, A. L.; D'Alessandro, W.; Tagliavia, M.; Parello, F.; Quatrini, P.

    2014-10-01

    Volcanic and geothermal systems emit endogenous gases by widespread degassing from soils, including CH4, a greenhouse gas twenty-five times as potent as CO2. Recently, it has been demonstrated that volcanic or geothermal soils are not only a source of methane, but are also sites of methanotrophic activity. Methanotrophs are able to consume 10-40 Tg of CH4 a-1 and to trap more than 50% of the methane degassing through the soils. We report on methane microbial oxidation in the geothermally most active site of Pantelleria (Italy), Favara Grande, whose total methane emission was previously estimated at about 2.5 Mg a-1 (t a-1). Laboratory incubation experiments with three top-soil samples from Favara Grande indicated methane consumption values of up to 59.2 nmol g-1 soil d.w. h-1. One of the three sites, FAV2, where the highest oxidation rate was detected, was further analysed on a vertical soil profile, the maximum methane consumption was measured in the top-soil layer, and values greater than 6.23 nmol g-1 h-1 were still detected up to a depth of 13 cm. The highest consumption rate was measured at 37 °C, but a still detectable consumption at 80 °C (> 1.25 nmol g-1 h-1) was recorded. The soil total DNA extracted from the three samples was probed by Polymerase Chain Reaction (PCR) using standard proteobacterial primers and newly designed verrucomicrobial primers, targeting the unique methane monooxygenase gene pmoA; the presence of methanotrophs was detected at sites FAV2 and FAV3, but not at FAV1, where harsher chemical-physical conditions and negligible methane oxidation were detected. The pmoA gene libraries from the most active site (FAV2) pointed to a high diversity of gammaproteobacterial methanotrophs, distantly related to Methylocaldum-Metylococcus genera, and the presence of the newly discovered acido-thermophilic Verrucomicrobia methanotrophs. Alphaproteobacteria of the genus Methylocystis were isolated from enrichment cultures under a methane

  1. Peak shapes of acids and bases under overloaded conditions in reversed-phase liquid chromatography, with weakly buffered mobile phases of various pH: A thermodynamic interpretation

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2009-01-01

    We measured overloaded band profiles for a series of nine compounds (phenol, caffeine, 3-phenyl 1-propanol, 2-phenylbutyric acid, amphetamine, aniline, benzylamine, p-toluidine, and procainamidium chloride) on columns packed with four different C{sub 18}-bonded packing materials: XTerra-C{sub 18}, Gemini-C{sub 18}, Luna-C{sub 18}(2), and Halo-C{sub 18}, using buffered methanol-water mobile phases. The {sub W}{sup S}pH of the mobile phase was increased from 2.6 to 11.3. The buffer concentration (either phosphate, acetate, or carbonate buffers) was set constant at values below the maximum concentration of the sample in the band. The influence of the surface chemistry of the packing material on the retention and the shape of the peaks was investigated. Adsorbents having a hybrid inorganic/organic structure tend to give peaks exhibiting moderate or little tailing. The retention and the shape of the band profiles can easily be interpreted at {sub W}{sup S}pHs that are well above or well below the {sub W}{sup S}pK{sub a} of the compound studied. In contrast, the peak shapes in the intermediary pH range (i.e., close to the compound {sub W}{sup S}pK{sub a}) have rarely been studied. These shapes reveal the complexity of the competitive adsorption behavior of couples of acido-basic conjugated compounds at {sub W}{sup S}pHs that are close to their {sub W}{sup S}pK{sub a}. They also reveal the role of the buffer capacity on the resulting peak shape. With increasing {sub W}{sup S}pH, the overloaded profiles are first langmuirian (isotherm type I) at low {sub W}{sup S}pHs, they become S-shaped (isotherm type II), then anti-langmuirian (isotherm type III), S-shaped again at intermediate {sub W}{sup S}pHs, and finally return to a langmuirian shape at high {sub W}{sup S}pHs. A new general adsorption isotherm model that takes into account the dissociation equilibrium of conjugated acidic and basic species in the bulk mobile phase accounts for these transient band shapes. An

  2. Effects of Long-Term Acid-Mine Drainage Contamination on Diversity and Activity of Sulfate-Reducing Bacteria in a Natural Salt Marsh.

    NASA Astrophysics Data System (ADS)

    Moreau, J. W.; Banfield, J. F.

    2003-12-01

    -grained black muds that are distinguishable from coarser pyrite cinders, and exhibit a noticeably strong sulfide odor. Aero- and halo-tolerant SRB were enriched from circumneutral pH cores, and we hypothesize that acido-tolerant SRB may also be present. Analysis of restriction fragment length polymorphism of whole community 16S rDNA extracted from each core shows an expected increase in diversity between acidic and circumneutal sediments, and clone libraries from both contaminated and uncontaminated marsh sediments are being compared to assess the impact of long-term contamination. References: Webb et al. 1998, J. Appl. Microbio., 84, 240-248; Moreau et al. 2003, Amer. Min., in review; URS Corp. 2001, Report 51.09967067.00.

  3. Assessment of a sequential extraction protocol by examining solution chemistry and mineralogical evolution

    NASA Astrophysics Data System (ADS)

    Maubec, Nicolas; Pauwels, Hélène; Noël, Hervé; Bourrat, Xavier

    2015-04-01

    of them are able to leach several solid phases. In this context, the aim of the present study is to investigate the effectiveness and the selectivity of different reagents for metal extraction from target geochemical fraction. It is based on solid analyses with the use of X-ray diffraction and a scanning electron microscopy (SEM) coupled to a microRaman spectrometer in conjunction with chemical analyses of extracting solutions at each step. This methodology provides the opportunity to assess more accurately the effect of each reagent. The study focuses on extraction of Cu and Zn from sediment samples collected at two sites from river banks and characterized by presence of Quartz, Feldspar K, Micas, Kaolinite but with differences regarding accessory phases (pyrite, organic matter, iron oxy- hydroxide, calcite). The interaction of the samples with eight different reagents was assessed and compared (Ca(NO3)2 and CaCl2 for the exchangeable fraction; buffered solutions of sodium acetate/acetic acid at pH = 5.5 and pH = 5 for the acido-soluble fraction; hydroxylamine hydrochloride and a solution of ammonium oxalate/oxalic acid for reducible fraction; hydrogen peroxide and sodium hypochlorite for the oxidizable fraction. In-depth characterization of solid residue at each step allowed proposing the best protocol for both metals. Anderson, P., Davidson, C. M., Duncan, A. L., Littlejohn, D., Ure, A. M., and Garden, L. M. (2000). Column leaching and sorption experiments to assess the mobility of potentially toxic elements in industrially contaminated land. Journal of Environmental Monitoring, 2. Arey, J. S., Seaman, J. C., and Bertsch, P. M. (1999). Immobilization of uranium in contaminated sediments by hydroxyapatite addition. Environmental Science & Technology, 33, 337-342. Brannon, J. M., and Patrick, W. H. (1987). Fixation, transformation, and mobilization of arsenic in sediments.Environmental Science & Technology, 21, 450-459. Cornu, S., and Clozel, B. (2000). Extractions

  4. Zinc, cadmium, and copper mobility and accumulation in reeds (Phragmites australis) in urban sediments from two stormwater infiltration basins

    NASA Astrophysics Data System (ADS)

    Bedell, J.-P.; Saulais, S.; Delolme, C.

    2012-04-01

    Infiltration basins are stormwater management techniques that are widely used to reduce stormwater volume. The settling of stormwater particles leads to a contaminated sediment layer at the basin surface. Phragmites australis used in constructed wetlands are widely present in infiltration basins. Such plant can play a role on the fate of heavy metals either directly by their uptake or indirectly by modification of physico-chemical characteristics of the sediment. The aim of this study is to assess Zn, Cd and Cu potential mobility and their bioaccumulation by reeds during plant's growth in urban sediments offering two different geochemical contexts. Methodology is based on the monitoring (in june, august and december) of physico-chemical characteristics of sediment deposit in two basins. These basins, "Minerve" and "Grézieu", located on both sides of Lyon city are characteristic of two different geochemical context. "Minerve" is in the east and "Grézieu" in the west part. The geology of the eastern part of Lyon is characterized by carbonated fluvio-glacial deposits. In the western part, the subsoil is mainly composed of gneiss and granit. Moreover, 20 cm of gravel and a sand layer were initially added at the surface of the "Grézieu" basin. In "Minerve", a clay material was initially added and a filter trench was built along the basin to allow water infiltration. We characterized the sediment deposit by the identification of their geochemical characteristics (Zn, Cu, Cd, total content, pH, CEC, C/N, carbonates and major elements contents …). Then we studied the potential mobility of the three metals by single chemical extraction (CaCl2 for the exchangeable phase, acetate buffer for the acido-soluble phase and diethylenetriamine-pentaacetic acid (DTPA) for the fraction associated to the organic matter). The accumulation of Zn, Cd and Cu in aerial parts and roots of the reeds was also measured. The results show clearly that "Grézieu" sediment is more enriched in

  5. Effet de la substitution du cuivre par du lithium sur les proprietes de l'oxyde spinelle lithium(x)cuivre(y-x)cobalt(3-y)oxygen(4) etudie pour l'electrocatalyse de la reaction de degagement de l'oxygene en milieu alcalin

    NASA Astrophysics Data System (ADS)

    Fatih, Khalid

    L'electrolyse de l'eau demeure la seule technologie industrielle de generation de l'hydrogene et de l'oxygene tres purs sans rejet de CO2 dans l'atmosphere, ce qui le rend tres attrayant par rapport a la combustion de carburants fossiles qui provoque presentement de serieux problemes environnementaux. Dans le but d'ameliorer le rendement de ce procede, nous avons developpe de nouveaux materiaux d'anode peu couteux, a base de l'oxyde mixte CuyCo3-yO 4, qui possedent une cinetique rapide pour la reaction de degagement de l'oxygene (RDO). Cette reaction suscite un interet particulier en raison de la surtension d'activation relativement elevee a l'anode qui cause la principale perte de rendement du procede. Une etude systematique a ete effectuee sur la substitution du Cu par du Li (0 a 40%), afin d'elucider les proprietes electrocatalytiques des oxydes LixCuy-xCo3-yO4. Ces oxydes, prepares sous forme de poudres par decomposition thermique des nitrates precurseurs entre 300 et 500°C, ont montre (DRX et FTIR) une structure spinelle inverse non-stcechiometrique avec une diminution du volume de la maille cristalline. La surface specifique par BET est d'environ 6 m2 g-1. Le pcn, obtenu par titrage acido-basique, a indique une diminution de la force du lien M-OH avec le taux du Li dans l'oxyde. Les analyses par XPS, realisees sur des films d'oxyde prepares par nebulisation reactive sur un substrat lisse de nickel, revelent un enrichissement de la surface en Cu a partir de 30% Li, et la presence des cations de surface Co2+, Co3+, Cu +, Cu2+ et Cu3+. La concentration de ce dernier montre un maximum a 10 et 20% Li. Suite a la substitution du Cu par du Li, la compensation de la charge serait assuree principalement par la formation d'especes Cu3+ pour les oxydes contenant jusqu'a 20% Li, et par la formation d'especes Co3+ aux taux de substitution superieurs. Les micrographies MEB montrent une morphologie hemispherique des particules d'oxyde reparties uniformement sur le substrat

  6. Facteurs de risque de mortalité par tuberculose pulmonaire

    PubMed Central

    Janah, Hicham; Souhi, Hicham; Kouismi, Hatim; Mark, Karima; Zahraoui, Rachida; Benamor, Jouda; Soualhi, Mona; Bourkadi, Jamal Eddine

    2014-01-01

    La tuberculose est une maladie infectieuse transmissible provoquée par myco-bacterium tuberculosis (bacille de Koch ou BK). Elle représente, selon les estimations del'Organisation Mondiale de la Santé (OMS), l'une des pathologies infectieuses causant le plus de décès au niveau mondial avec plus de 1 million de décès par an. Pour déterminer les facteurs de risque de mortalité au cours de la tuberculose pulmonaire à microscopie positive nous avons mené une étude rétrospective portant sur tous les cas de tuberculose pulmonaire à microscopie positive et qui étaient décédés au cours de leur hospitalisation. Cette étude a colligé 1803 cas de tuberculose sur une période de 2 ans et demi dont 46 sont décédés. La prévalence de décès est de 2,55%. La population se répartit en 32 hommes et 14 femmes. L’âge moyen était de 53ans ± 17 ans. Le tabagisme était retrouvé chez la moitié des cas. Une comorbidité était retrouvée dans 43%, avec 17% de diabète. Le délai de diagnostic avait une médiane de 60 jours avec percentile (30j; 105j). La symptomatologie clinique était dominée par la toux, la dyspnée et les expectorations soit respectivement: 97,8%, 69,6% et 67,4% des cas. Sur le plan radiologique les lésions étaient diffuses et bilatérales dans 76,1% des cas. Tous les patients étaient mis sous SRHZ. 11% avaient présenté une toxicité aux antibacillaires (de type hépatiques dans 3 cas et neurologiques dans 2 cas). Le délai médian de décès était de 8,5 jours (5j; 17j). Les causes de décès retrouvées étaient: Une hépatite fulminante (3 cas), une décompensation acido-cétosique (3 cas), un SDRA (2 cas), des hémoptysies foudroyantes (2 cas), et respectivement un cas secondaire à une décompensation de BPCO, une décompensation cardiaque, une hypoglycémie et un tableau d'anasarque. Cette étude suggère que le terrain, le retard diagnostique et les effets secondaires du traitement sont les principaux facteurs de risque de

  7. Assessment of a sequential extraction protocol by examining solution chemistry and mineralogical evolution

    NASA Astrophysics Data System (ADS)

    Maubec, Nicolas; Pauwels, Hélène; Noël, Hervé; Bourrat, Xavier

    2015-04-01

    of them are able to leach several solid phases. In this context, the aim of the present study is to investigate the effectiveness and the selectivity of different reagents for metal extraction from target geochemical fraction. It is based on solid analyses with the use of X-ray diffraction and a scanning electron microscopy (SEM) coupled to a microRaman spectrometer in conjunction with chemical analyses of extracting solutions at each step. This methodology provides the opportunity to assess more accurately the effect of each reagent. The study focuses on extraction of Cu and Zn from sediment samples collected at two sites from river banks and characterized by presence of Quartz, Feldspar K, Micas, Kaolinite but with differences regarding accessory phases (pyrite, organic matter, iron oxy- hydroxide, calcite). The interaction of the samples with eight different reagents was assessed and compared (Ca(NO3)2 and CaCl2 for the exchangeable fraction; buffered solutions of sodium acetate/acetic acid at pH = 5.5 and pH = 5 for the acido-soluble fraction; hydroxylamine hydrochloride and a solution of ammonium oxalate/oxalic acid for reducible fraction; hydrogen peroxide and sodium hypochlorite for the oxidizable fraction. In-depth characterization of solid residue at each step allowed proposing the best protocol for both metals. Anderson, P., Davidson, C. M., Duncan, A. L., Littlejohn, D., Ure, A. M., and Garden, L. M. (2000). Column leaching and sorption experiments to assess the mobility of potentially toxic elements in industrially contaminated land. Journal of Environmental Monitoring, 2. Arey, J. S., Seaman, J. C., and Bertsch, P. M. (1999). Immobilization of uranium in contaminated sediments by hydroxyapatite addition. Environmental Science & Technology, 33, 337-342. Brannon, J. M., and Patrick, W. H. (1987). Fixation, transformation, and mobilization of arsenic in sediments.Environmental Science & Technology, 21, 450-459. Cornu, S., and Clozel, B. (2000). Extractions

  8. The extreme environments and their microbes as models for extraterrestrial life

    NASA Astrophysics Data System (ADS)

    Seckbach, J.; Oren, A.; Chela-Flores, J.

    2008-09-01

    Life exists almost everywhere on Earth. Presence of liquid water is a prerequisite for life (Oren, 2008). Living organisms are not only found in `normal' habitats (from the anthropocentric view). Many types, especially of microorganisms, not only tolerate harsh environmental conditions, but even thive in them. Such organisms that resist very harsh physical and chemical conditions in their habitats are termed `extremophiles'. Some extremophilic microorganisms are able to overcome more than one type of extreme conditions in their environment. For example, some `polyextremophiles' grow under hundreds of atmospheres of hydrostatic pressure (barophiles) and at very low, or alternatively at very high temperatures. In many hot springs there are acido-thermophiles that tolerate elevated temperatures and very low pH levels (e.g. the Cyanidium caldarium group, see Seckbach 1994). Members of Cyanidium are able to thrive in pure CO2, a condition not tolerated by most algae (Seckbach et al., 1970). Some thermophilic Archaea grow at temperatures up to 1130C and possibly even higher. In the Arctic and Antarctic regions and in the permafrost region in Siberia there are cold-loving microorganisms (psychrophiles) which are able to grow at -200C. Many types of Bacteria and Archaea tolerate extreme dryness, and spores of Bacillus and relatives that have been encapsulated within salt crystals may have survived in a dormant state for thousands and even millions of years, and still can be revived today. Other extremophiles tolerate salt concentrations up to saturation. Halophilic microorganisms such as found in the Dead Sea or in the Great Salt Lake have developed different strategies to cope with the high osmotic pressure of their environment. Some (e.g. the unicellular green alga Dunaliella salina) balance the salts in their medium by accumulating organic compounds such as glycerol. Others (halophilic Archaea of the order Halobacteriales, as well as a few representatives of the