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Sample records for membrane lysis extraction

  1. The solubilisation of boar sperm membranes by different detergents - a microscopic, MALDI-TOF MS, 31P NMR and PAGE study on membrane lysis, extraction efficiency, lipid and protein composition

    Directory of Open Access Journals (Sweden)

    Müller Karin

    2009-11-01

    Full Text Available Abstract Background Detergents are often used to isolate proteins, lipids as well as "detergent-resistant membrane domains" (DRMs from cells. Different detergents affect different membrane structures according to their physico-chemical properties. However, the effects of different detergents on membrane lysis of boar spermatozoa and the lipid composition of DRMs prepared from the affected sperm membranes have not been investigated so far. Results Spermatozoa were treated with the selected detergents Pluronic F-127, sodium cholate, CHAPS, Tween 20, Triton X-100 and Brij 96V. Different patterns of membrane disintegration were observed by light and electron microscopy. In accordance with microscopic data, different amounts of lipids and proteins were released from the cells by the different detergents. The biochemical methods to assay the phosphorus and cholesterol contents as well as 31P NMR to determine the phospholipids were not influenced by the presence of detergents since comparable amounts of lipids were detected in the organic extracts from whole cell suspensions after exposure to each detergent. However, matrix-assisted laser desorption and ionization time-of-flight mass spectrometry applied to identify phospholipids was essentially disturbed by the presence of detergents which exerted particular suppression effects on signal intensities. After separation of the membrane fractions released by detergents on a sucrose gradient only Triton X-100 and sodium cholate produced sharp turbid DRM bands. Only membrane solubilisation by Triton X-100 leads to an enrichment of cholesterol, sphingomyelin, phosphatidylinositol and phosphatidylethanolamine in a visible DRM band accompanied by a selective accumulation of proteins. Conclusion The boar sperm membranes are solubilised to a different extent by the used detergents. Particularly, the very unique DRMs isolated after Triton X-100 exposure are interesting candidates for further studies regarding the

  2. Direct Cellular Lysis/Protein Extraction Protocol for Soil Metaproteomics

    Energy Technology Data Exchange (ETDEWEB)

    Chourey, Karuna [ORNL; Jansson, Janet [Lawrence Berkeley National Laboratory (LBNL); Verberkmoes, Nathan C [ORNL; Shah, Manesh B [ORNL; Chavarria, Krystle L. [Lawrence Berkeley National Laboratory (LBNL); Tom, Lauren M [Lawrence Berkeley National Laboratory (LBNL); Brodie, Eoin L. [Lawrence Berkeley National Laboratory (LBNL); Hettich, Robert {Bob} L [ORNL

    2010-01-01

    We present a novel direct protocol for deep proteome characterization of microorganisms in soil. The method employs thermally assisted detergent-based cellular lysis (SDS) of soil samples, followed by TCA precipitation for proteome extraction/cleanup prior to liquid chromatography-mass spectrometric characterization. This approach was developed and optimized using different soils inoculated with genome-sequenced bacteria (Gram-negative Pseudomonas putida or Gram-positive Arthrobacter chlorophenolicus). Direct soil protein extraction was compared to protein extraction from cells isolated from the soil matrix prior to lysis (indirect method). Each approach resulted in identification of greater than 500 unique proteins, with a wide range in molecular mass and functional categories. To our knowledge, this SDS-TCA approach enables the deepest proteome characterizations of microbes in soil to date, without significant biases in protein size, localization, or functional category compared to pure cultures. This protocol should provide a powerful tool for ecological studies of soil microbial communities.

  3. Direct cellular lysis/protein extraction protocol for soil metaproteomics.

    Science.gov (United States)

    Chourey, Karuna; Jansson, Janet; VerBerkmoes, Nathan; Shah, Manesh; Chavarria, Krystle L; Tom, Lauren M; Brodie, Eoin L; Hettich, Robert L

    2010-12-03

    We present a novel direct protocol for deep proteome characterization of microorganisms in soil. The method employs thermally assisted detergent-based cellular lysis (SDS) of soil samples, followed by TCA precipitation for proteome extraction/cleanup prior to liquid chromatography-mass spectrometric characterization. This approach was developed and optimized using different soils inoculated with genome-sequenced bacteria (Gram-negative Pseudomonas putida or Gram-positive Arthrobacter chlorophenolicus). Direct soil protein extraction was compared to protein extraction from cells isolated from the soil matrix prior to lysis (indirect method). Each approach resulted in identification of greater than 500 unique proteins, with a wide range in molecular mass and functional categories. To our knowledge, this SDS-TCA approach enables the deepest proteome characterizations of microbes in soil to date, without significant biases in protein size, localization, or functional category compared to pure cultures. This protocol should provide a powerful tool for ecological studies of soil microbial communities.

  4. Lysis of Microcystis aeruginosa with Extracts from Chinese Medicinal Herbs

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    Yu-Fen Yin

    2009-09-01

    Full Text Available Boiling water extracts of 66 selected Chinese medicinal herbs were screened for their anticyanobaterial activity against Microcystis aeruginosa by the soft-agar overlayer (SAO method. Results indicated that extracts from 16 materials could inhibit the growth of this bacterial species. Among these anticyanobacterial samples, eight extracts showed low minimum inhibitory concentrations (MIC, including four extracts with MICs between 1 and 6 mg/mL, and four extracts with MICs < 1 mg/mL which could be considered useful to prevent the outbreak of cyanobacteria before the appearance of cyanobacterial blooms. Further study showed that three extracts with MIC values < 1 mg/mL induced intensive chlorophyll-a lysis within 7 days at the MIC. The results suggested that highly efficient anticyanobacterial compounds must be involved in the inhibitory activities. The final results indicated these three extracts (from Malaphis chinensis, Cynips gallae-tinctoriae and Fructus mume had the potential to be developed as algicides due to their remarkably anticyanobacterial activities.

  5. Cell lysis induced by membrane-damaging detergent saponins from Quillaja saponaria.

    Science.gov (United States)

    Berlowska, Joanna; Dudkiewicz, Marta; Kregiel, Dorota; Czyzowska, Agata; Witonska, Izabela

    2015-01-01

    This paper presents the results of a study to determine the effect of Quillaja saponaria saponins on the lysis of industrial yeast strains. Cell lysis induced by saponin from Q. saponaria combined with the plasmolysing effect of 5% NaCl for Saccharomyces cerevisiae, Kluyveromyces marxianus yeasts biomass was conducted at 50 °C for 24-48 h. Membrane permeability and integrity of the yeast cells were monitored using fluorescent techniques and concentrations of proteins, free amino nitrogen (FAN) and free amino acids in resulting lysates were analyzed. Protein release was significantly higher in the case of yeast cell lysis promoted with 0.008% Q. saponaria and 5% NaCl in comparison to plasmolysis triggered by NaCl only. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Electrophoretic Concentration and Electrical Lysis of Bacteria in a Microfluidic Device Using a Nanoporous Membrane

    Directory of Open Access Journals (Sweden)

    Md. Shehadul Islam

    2017-02-01

    Full Text Available Pathogenic bacteria such as Escherichia coli O157, Salmonella and Campylobacter are the main causes for food and waterborne illnesses. Lysis of these bacteria is an important component of the sample preparation for molecular identification of these pathogens. The pathogenicity of these bacteria is so high that they cause illness at very low concentrations (1–10 CFU/100 mL. Hence, there is a need to develop methods to collect a small number of such bacterial cells from a large sample volume and process them in an automated reagent-free manner. An electrical method to concentrate the bacteria and lyse them has been chosen here as it is reagent free and hence more conducive for online and automated sample preparation. We use commercially available nanoporous membranes sandwiched between two microfluidic channels to create thousands of parallel nanopore traps for bacteria, electrophoretically accumulate and then lyse them. The nanopores produce a high local electric field for lysis at moderate applied voltages, which could simplify instrumentation and enables lysis of the bacteria as it approaches them under an appropriate range of electric field (>1000 V/cm. Accumulation and lysis of bacteria on the nanoporous membrane is demonstrated by using the LIVE/DEAD BacLight Bacterial Viability Kit and quantified by fluorescence intensity measurements. The efficiency of the device was determined through bacterial culture of the lysate and was found to be 90% when a potential of 300 V was applied for 3 min.

  7. All-in-one nanowire-decorated multifunctional membrane for rapid cell lysis and direct DNA isolation.

    KAUST Repository

    So, Hongyun

    2014-11-24

    This paper describes a handheld device that uses an all-in-one membrane for continuous mechanical cell lysis and rapid DNA isolation without the assistance of power sources, lysis reagents, and routine centrifugation. This nanowire-decorated multifunctional membrane was fabricated to isolate DNA by selective adsorption to silica surface immediately after disruption of nucleus membranes by ultrasharp tips of nanowires for a rapid cell lysis, and it can be directly assembled with commercial syringe filter holders. The membrane was fabricated by photoelectrochemical etching to create microchannel arrays followed by hydrothermal synthesis of nanowires and deposition of silica. The proposed membrane successfully purifies high-quality DNA within 5 min, whereas a commercial purification kit needs more than an hour.

  8. [Extraction of sperm DNA from mixed stain by the modified differential lysis method combined with silicon bead method].

    Science.gov (United States)

    Han, Hai-Jun; Zhang, Yu-Hong; Yang, Min; Yi, Hai; Yang, Geng-Ye; Jia, Dong-Tao; Lu, Da-Ru

    2014-02-01

    To extract sperm DNA from mixed stain by the modified differential lysis method combined with silicon bead method and to evaluate its application value. Fifty-two mixed stains containing female STR genotypes detected by differential lysis method were collected. The sperm DNA was extracted by the modified method combined with silicon bead method, then genotyped with the Identifiler Kit, and compared with the results of genotyping by the conventional differential lysis method as control. Of the 52 samples, 38 samples with sole male STR genotypes in all loci were detected. The detection rate of male STR genotypes was 98.08% through the modified method combined with silicon bead method. The modified differential lysis method combined with silicon bead method can be used in extraction of sperm DNA from mixed stain.

  9. Improved aqueous extraction of microalgal lipid by combined enzymatic and thermal lysis from wet biomass of Nannochloropsis oceanica.

    Science.gov (United States)

    Chen, Lin; Li, Runzhi; Ren, Xiaoli; Liu, Tianzhong

    2016-08-01

    High moisture content in wet algal biomass hinders effective performance of current lipid extraction methods. An improved aqueous extraction method combing thermal and enzymatic lysis was proposed and performed in algal slurry of Nannochloropsis oceanica (96.0% moisture) in this study. In general, cell-wall of N. oceanica was disrupted via thermal lysis and enzymatic lysis and lipid extraction was performed using aqueous surfactant solution. At the optimal conditions, high extraction efficiencies for both lipid (88.3%) and protein (62.4%) were obtained, which were significantly higher than those of traditional hexane extraction and other methods for wet algal biomass. Furthermore, an excessive extraction of polar lipid was found for wet biomass compared with dry biomass. The advantage of this method is to efficiently extract lipids from high moisture content algal biomass and avoid using organic solvent, indicating immense potential for commercial microalgae-based biofuel production. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Parallel artificial liquid membrane extraction

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Rasmussen, Knut Einar; Parmer, Marthe Petrine

    2013-01-01

    This paper reports development of a new approach towards analytical liquid-liquid-liquid membrane extraction termed parallel artificial liquid membrane extraction. A donor plate and acceptor plate create a sandwich, in which each sample (human plasma) and acceptor solution is separated by an arti...... by an artificial liquid membrane. Parallel artificial liquid membrane extraction is a modification of hollow-fiber liquid-phase microextraction, where the hollow fibers are replaced by flat membranes in a 96-well plate format....

  11. [PrepFiler Express BTATM Lysis Buffer Combined with Silicon Microbeads for Rapid DNA Extraction from Bone].

    Science.gov (United States)

    Ding, S C; Zhang, H C; Gao, L L

    2017-10-01

    To establish a convenient and rapid method for extracting DNA from bone. Fifteen long bone samples were washed and sterilized. The skeletal fragments were obtained by electric drill, and lysed by PrepFiler Express BTA™ lysis buffer. DNA was then manually extracted by silicon microbeads for further analysis. STR genotyping was successfully obtained in 14 out of the 15 samples, and the detection rate was 93.33%. The method for DNA extraction from bone established in present study is convenient, quick, effective, and with a strong applicability, which is worth spreading and applying. Copyright© by the Editorial Department of Journal of Forensic Medicine

  12. Solid phase extraction membrane

    Science.gov (United States)

    Carlson, Kurt C [Nashville, TN; Langer, Roger L [Hudson, WI

    2002-11-05

    A wet-laid, porous solid phase extraction sheet material that contains both active particles and binder and that possesses excellent wet strength is described. The binder is present in a relatively small amount while the particles are present in a relatively large amount. The sheet material is sufficiently strong and flexible so as to be pleatable so that, for example, it can be used in a cartridge device.

  13. Ionic liquids for the concomitant use in extremophiles lysis and extremozymes extraction.

    Science.gov (United States)

    Gutiérrez-Arnillas, E; Deive, F J; Sanromán, M A; Rodríguez, A

    2015-06-01

    Ionic liquids have been successfully proposed to modify membrane permeability in cultures of a model extremophilic bacterium Thermus thermophilus HB27, which makes up the first time that aqueous solutions of these molten salts are applied in downstream stages of this kind of microorganisms. The presence of 1g/L of C10MIMCl entails a great solubilisation of cell biomass, thus allowing the release of intracellular and membrane-bound enzyme. The influence on the enzyme activity of two inorganic salts such as Na2CO3 and (NH4)2SO4, selected on the basis of their high salting out potential and biocompatibility with enzymes, respectively, was investigated. In parallel, their ability to trigger phase segregation was confirmed in the presence of the enzyme crude, leading to very high levels of enzyme extraction (96%). The validity of the strategy was confirmed by operating at bioreactor scale, and the main bioprocess parameters were obtained by modelling the experimental data. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. An adhesion-based method for plasma membrane isolation: evaluating cholesterol extraction from cells and their membranes.

    Science.gov (United States)

    Bezrukov, Ludmila; Blank, Paul S; Polozov, Ivan V; Zimmerberg, Joshua

    2009-11-15

    A method to isolate large quantities of directly accessible plasma membrane from attached cells is presented. The method is based on the adhesion of cells to an adsorbed layer of polylysine on glass plates, followed by hypotonic lysis with ice-cold distilled water and subsequent washing steps. Optimal conditions for coating glass plates and time for cell attachment were established. No additional chemical or mechanical treatments were used. Contamination of the isolated plasma membrane by cell organelles was less than 5%. The method uses inexpensive, commercially available polylysine and reusable glass plates. Plasma membrane preparations can be made in 15 min. Using this method, we determined that methyl-beta-cyclodextrin differentially extracts cholesterol from fibroblast cells and their plasma membranes and that these differences are temperature dependent. Determination of the cholesterol/phospholipid ratio from intact cells does not reflect methyl-beta-cyclodextrin plasma membrane extraction properties.

  15. Very High Throughput Electrical Cell Lysis and Extraction of Intracellular Compounds Using 3D Carbon Electrodes in Lab-on-a-Chip Devices

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    Philippe Renaud

    2012-08-01

    Full Text Available Here we present an electrical lysis throughput of 600 microliters per minute at high cell density (108 yeast cells per ml with 90% efficiency, thus improving the current common throughput of one microliter per minute. We also demonstrate the extraction of intracellular luciferase from mammalian cells with efficiency comparable to off-chip bulk chemical lysis. The goal of this work is to develop a sample preparation module that can act as a stand-alone device or be integrated to other functions already demonstrated in miniaturized devices, including sorting and analysis, towards a true lab-on-a-chip.

  16. Handheld mechanical cell lysis chip with ultra-sharp silicon nano-blade arrays for rapid intracellular protein extraction.

    Science.gov (United States)

    Yun, Sung-Sik; Yoon, Sang Youl; Song, Min-Kyung; Im, Sin-Hyeog; Kim, Sohee; Lee, Jong-Hyun; Yang, Sung

    2010-06-07

    This paper presents a handheld mechanical cell lysis chip with ultra-sharp nano-blade arrays fabricated by simple and cost effective crystalline wet etching of (110) silicon. The ultra-sharp nano-blade array is simply formed by the undercutting of (110) silicon during the crystalline wet etching process. Cells can be easily disrupted by the silicon nano-blade array without the help of additional reagents or electrical sources. Based on the bench-top test of the proposed device, a handheld mechanical cell lysis chip with the nano-blade arrays is designed and fabricated for direct connection to a commercial syringe. The direct connection to a syringe provides rapid cell lysis, easy handling, and minimization of the lysate dead volume. The protein concentration in the cell lysate obtained by the proposed lysis chip is quantitatively comparable to the one prepared by a conventional chemical lysis method.

  17. Primary metals extraction by liquid membranes

    International Nuclear Information System (INIS)

    Subramanian, K.N.

    1980-01-01

    The extraction of copper and uranium by liquid membranes is presented. The recovery of uranium from wet process phosphoric acid is described. The development of this process has progressed through three stages, firstly the chemistry of uranium extraction as it pertains to liquid membrane systems. This was followed by continuous extraction tests on fresh black acid and on aged acid. Results on a 1 litre/minute pilot plant demonstrated that the process could be operated with a minimum of feed pretreatment and about 90% of uranium could be extracted. The extraction of copper from copper leach liquors is also described. (U.K.)

  18. On-chip electro membrane extraction

    DEFF Research Database (Denmark)

    Petersen, Nickolaj Jacob; Jensen, Henrik; Hansen, Steen Honore

    2010-01-01

    This paper presents the first downscaling of electro membrane extraction (EME) to a chip format. The voltage-controlled extraction for sample preparation on microfluidic devices has several advantages such as selective extraction removing the high ionic strength of biological samples, preconcentr...

  19. Extraction of uranium with emulsion membrane process use tributylphosphate extractant

    International Nuclear Information System (INIS)

    Basuki, K.T.; Sudibyo, R.; Bambang EHB; Muhadi, A.W.

    1996-01-01

    To increase the effectiveness of extraction process with so for to occur, it was tried the extraction with a couple of extraction and stripping process. This couple process was called liquid membrane emulsion. As membrane was used mix surfactant (Span-80), tributylphosphate in kerosene, natrium carbonate, while as a feeder was uranium solution with 500 concentration ppm in 0.5 - 3 M nitrate acid. In this experiment the variable investigated were % surfactant (1 - 5 %), rotary speed for membrane making (2,500 - 10.000 rpm). The optimal condition result of experiment were 5 % surfactant, 3 M nitrate acid, rotary speed 10.000 rpm and (Kd eksU ) 57 %, and (Kd strippU ) 87 %, Kd eksU at liquid-liquid extraction is 44 %. (author)

  20. hollow fibre supported liquid membrane extraction of ...

    African Journals Online (AJOL)

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    ABSTRACT. ABSTRACT. A simple sample pre-treatment method utilizing hollow fibre supported liquid membrane. (HFSLM) was carried out on pharmaceuticals samples comprising of cough syrups (CS1 and CS2) and an anti- inflammatory product (AI). The active ingredients targeted in the extraction process were ...

  1. Hollow fibre supported liquid membrane extraction of ...

    African Journals Online (AJOL)

    A simple sample pre-treatment method utilizing hollow fibre supported liquid membrane (HFSLM) was carried out on pharmaceuticals samples comprising of cough syrups (CS1 and CS2) and an anti-inflammatory product (AI). The active ingredients targeted in the extraction process were diphenylhydramine (DPH), ...

  2. Extraction and identification of membrane proteins from black widow spider eggs.

    Science.gov (United States)

    Fu, Si-Ling; Li, Jiang-Lin; Chen, Jia; Wang, Qiu-Ting; Li, Jian-Jun; Wang, Xian-Chun

    2015-07-18

    The eggs of oviparous animals are storehouses of maternal proteins required for embryonic development. Identification and molecular characterization of such proteins will provide much insight into the regulation of embryonic development. We previously analyzed soluble proteins in the eggs of the black widow spider (Latrodectus tredecimguttatus), and report here on the extraction and mass spectrometric identification of the egg membrane proteins. Comparison of different lysis solutions indicated that the highest extraction of the membrane proteins was achieved with 3%-4% sodium laurate in 40 mmol/L Tris-HCl buffer containing 4% CHAPS and 2% DTT (pH 7.4). SDS-PAGE combined with nLC-MS/MS identified 39 proteins with membrane-localization annotation, including those with structural, catalytic, and regulatory activities. Nearly half of the identified membrane proteins were metabolic enzymes involved in various cellular processes, particularly energy metabolism and biosynthesis, suggesting that relevant metabolic processes were active during the embryonic development of the eggs. Several identified cell membrane proteins were involved in the special structure formation and function of the egg cell membranes. The present proteomic analysis of the egg membrane proteins provides new insight into the molecular mechanisms of spider embryonic development.

  3. A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer

    Science.gov (United States)

    Arif, Ibrahim A.; Bakir, Mohammad A.; Khan, Haseeb A.; Ahamed, Anis; Al Farhan, Ahmad H.; Al Homaidan, Ali A.; Al Sadoon, Mohammad; Bahkali, Ali H.; Shobrak, Mohammad

    2010-01-01

    Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae) and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl), polyvinylpyrrolidone (PVP) and lithium chloride (LiCl) with the cetyltrimethylammonium bromide (CTAB) method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M) in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification. PMID:20957085

  4. Extraction by means of emulsified liquid membranes

    International Nuclear Information System (INIS)

    Pareau, D.; Stambouli, M.

    2006-01-01

    It is an alternative of the liquid-liquid extraction process where extraction and stripping are simultaneously carried out. The stripping solution is dispersed in the solvent in micro-droplets. This emulsion, stabilised by a surface-active agent, is then dispersed in the liquid to be treated and, during that step, the metal is transferred to the stripping solution, moving through the solvent which operates as an organic membrane. The paper describes in detail the mechanism of the process, its advantages and its disadvantages. Its field of applications is wide, but only a few units are now industrially in operation, most of them exists only at the pilot scale. It is particularly adapted for the treatment of effluents with a very low content in metallic impurities. As examples, the paper describes the recovery of zinc from viscose plant effluents (Lenzing plant, Austria) and the removal of free cyanide ions and cyanide metallic complexes (pilot scale). (authors)

  5. Factors influencing lysis time stochasticity in bacteriophage λ

    Directory of Open Access Journals (Sweden)

    Dennehy John J

    2011-08-01

    Full Text Available Abstract Background Despite identical genotypes and seemingly uniform environments, stochastic gene expression and other dynamic intracellular processes can produce considerable phenotypic diversity within clonal microbes. One trait that provides a good model to explore the molecular basis of stochastic variation is the timing of host lysis by bacteriophage (phage. Results Individual lysis events of thermally-inducible λ lysogens were observed using a temperature-controlled perfusion chamber mounted on an inverted microscope. Both mean lysis time (MLT and its associated standard deviation (SD were estimated. Using the SD as a measure of lysis time stochasticity, we showed that lysogenic cells in controlled environments varied widely in lysis times, and that the level of lysis time stochasticity depended on allelic variation in the holin sequence, late promoter (pR' activity, and host growth rate. In general, the MLT was positively correlated with the SD. Both lower pR' activities and lower host growth rates resulted in larger SDs. Results from premature lysis, induced by adding KCN at different time points after lysogen induction, showed a negative correlation between the timing of KCN addition and lysis time stochasticity. Conclusions Taken together with results published by others, we conclude that a large fraction of λ lysis time stochasticity is the result of random events following the expression and diffusion of the holin protein. Consequently, factors influencing the timing of reaching critical holin concentrations in the cell membrane, such as holin production rate, strongly influence the mean lysis time and the lysis time stochasticity.

  6. Membrane contactor assisted extraction/reaction process employing ionic liquids

    Science.gov (United States)

    Lin, Yupo J [Naperville, IL; Snyder, Seth W [Lincolnwood, IL

    2012-02-07

    The present invention relates to a functionalized membrane contactor extraction/reaction system and method for extracting target species from multi-phase solutions utilizing ionic liquids. One preferred embodiment of the invented method and system relates to an extraction/reaction system wherein the ionic liquid extraction solutions act as both extraction solutions and reaction mediums, and allow simultaneous separation/reactions not possible with prior art technology.

  7. Lysis of lysis-inhibited bacteriophage T4-infected cells.

    OpenAIRE

    Abedon, S T

    1992-01-01

    T4 bacteriophage (phage)-infected cells show a marked increase in latent-period length, called lysis inhibition, upon adsorption of additional T4 phages (secondary adsorption). Lysis inhibition is a complex phenotype requiring the activity of at least six T4 genes. Two basic mysteries surround our understanding of the expression of lysis inhibition: (i) the mechanism of initiation (i.e., how secondary adsorption leads to the expression of lysis inhibition) and (ii) the mechanism of lysis (i.e...

  8. Solubilization of proteins: the importance of lysis buffer choice.

    Science.gov (United States)

    Peach, Mandy; Marsh, Noelle; Miskiewicz, Ewa I; MacPhee, Daniel J

    2015-01-01

    The efficient extraction of proteins of interest from cells and tissues is not always straightforward. Here we demonstrate the differences in extraction of the focal adhesion protein Kindlin-2 from choriocarcinoma cells using NP-40 and RIPA lysis buffer. Furthermore, we demonstrate the use of a more denaturing urea/thiourea lysis buffer for solubilization, by comparing its effectiveness for solubilization of small heat-shock proteins from smooth muscle with the often utilized RIPA lysis buffer. Overall, the results demonstrate the importance of establishing the optimal lysis buffer for specific protein solubilization within the experimental workflow.

  9. Detergent selection for enhanced extraction of membrane proteins.

    Science.gov (United States)

    Arachea, Buenafe T; Sun, Zhen; Potente, Nina; Malik, Radhika; Isailovic, Dragan; Viola, Ronald E

    2012-11-01

    Generating stable conditions for membrane proteins after extraction from their lipid bilayer environment is essential for subsequent characterization. Detergents are the most widely used means to obtain this stable environment; however, different types of membrane proteins have been found to require detergents with varying properties for optimal extraction efficiency and stability after extraction. The extraction profiles of several detergent types have been examined for membranes isolated from bacteria and yeast, and for a set of recombinant target proteins. The extraction efficiencies of these detergents increase at higher concentrations, and were shown to correlate with their respective CMC values. Two alkyl sugar detergents, octyl-β-d-glucoside (OG) and 5-cyclohexyl-1-pentyl-β-d-maltoside (Cymal-5), and a zwitterionic surfactant, N-decylphosphocholine (Fos-choline-10), were generally effective in the extraction of a broad range of membrane proteins. However, certain detergents were more effective than others in the extraction of specific classes of integral membrane proteins, offering guidelines for initial detergent selection. The differences in extraction efficiencies among this small set of detergents supports the value of detergent screening and optimization to increase the yields of targeted membrane proteins. Copyright © 2012 Elsevier Inc. All rights reserved.

  10. Guava Leaf Extract Inhibits Quorum-Sensing and Chromobacterium violaceum Induced Lysis of Human Hepatoma Cells: Whole Transcriptome Analysis Reveals Differential Gene Expression

    Science.gov (United States)

    Tiwary, Bipransh Kumar; Kumar, Anoop

    2014-01-01

    Quorum sensing (QS) is a process mediated via small molecules termed autoinducers (AI) that allow bacteria to respond and adjust according to the cell population density by altering the expression of multitudinous genes. Since QS governs numerous bioprocesses in bacteria, including virulence, its inhibition promises to be an ideal target for the development of novel therapeutics. We found that the aqueous leaf extract of Psidium guajava (GLE) exhibited anti-QS properties as evidenced by inhibition of violacein production in Chromobacterium violaceum and swarming motility of Pseudomonas aeruginosa. The gram-negative bacterium, C. violaceum is a rare pathogen with high mortality rate. In this study, perhaps for the first time, we identified the target genes of GLE in C. violaceum MTCC 2656 by whole transcriptome analysis on Ion Torrent. Our data revealed that GLE significantly down-regulated 816 genes at least three fold, with p value≤0.01, which comprises 19% of the C. violaceum MTCC 2656 genome. These genes were distributed throughout the genome and were associated with virulence, motility and other cellular processes, many of which have been described as quorum regulated in C. violaceum and other gram negative bacteria. Interestingly, GLE did not affect the growth of the bacteria. However, consistent with the gene expression pattern, GLE treated C. violaceum cells were restrained from causing lysis of human hepatoma cell line, HepG2, indicating a positive relationship between the QS-regulated genes and pathogenicity. Overall, our study proposes GLE as a QS inhibitor (QSI) with the ability to attenuate virulence without affecting growth. To the best of our knowledge, this is the first report which provides with a plausible set of candidate genes regulated by the QS system in the neglected pathogen C. violaceum. PMID:25229331

  11. Supported liquid membrane extraction of 17β- estradiol and its ...

    African Journals Online (AJOL)

    Administrator

    2006-10-02

    Oct 2, 2006 ... A sample purification and enrichment technique involving the use of supported liquid membrane (SLM) has been developed for the selective extraction of 17β- estradiol and its metabolites, namely 17β-estriol and estrone in various biological matrices and water. The biological matrices in which extraction ...

  12. Supported Liquid Membrane Extraction of Anabolic Androgenic ...

    African Journals Online (AJOL)

    A sample work-up and enrichment technique involving the use of supported liquid membrane (SLM) and detection by high performance liquid chromatography coupled to a mass spectrometer operating under positive ion electrospray mode (LC-PI-ESI-MS) has been developed for the determination of six anabolic ...

  13. Supported Liquid Membrane Extraction of Anabolic Androgenic ...

    African Journals Online (AJOL)

    NJD

    A sample work-up and enrichment technique involving the use of supported liquid membrane (SLM) and detection by high performance liquid chromatography coupled to a mass spectrometer operating under positive ion electrospray mode. (LC-PI-ESI-MS) has been developed for the determination of six anabolic ...

  14. Structuring detergents for extracting and stabilizing functional membrane proteins.

    Directory of Open Access Journals (Sweden)

    Rima Matar-Merheb

    Full Text Available BACKGROUND: Membrane proteins are privileged pharmaceutical targets for which the development of structure-based drug design is challenging. One underlying reason is the fact that detergents do not stabilize membrane domains as efficiently as natural lipids in membranes, often leading to a partial to complete loss of activity/stability during protein extraction and purification and preventing crystallization in an active conformation. METHODOLOGY/PRINCIPAL FINDINGS: Anionic calix[4]arene based detergents (C4Cn, n=1-12 were designed to structure the membrane domains through hydrophobic interactions and a network of salt bridges with the basic residues found at the cytosol-membrane interface of membrane proteins. These compounds behave as surfactants, forming micelles of 5-24 nm, with the critical micellar concentration (CMC being as expected sensitive to pH ranging from 0.05 to 1.5 mM. Both by 1H NMR titration and Surface Tension titration experiments, the interaction of these molecules with the basic amino acids was confirmed. They extract membrane proteins from different origins behaving as mild detergents, leading to partial extraction in some cases. They also retain protein functionality, as shown for BmrA (Bacillus multidrug resistance ATP protein, a membrane multidrug-transporting ATPase, which is particularly sensitive to detergent extraction. These new detergents allow BmrA to bind daunorubicin with a Kd of 12 µM, a value similar to that observed after purification using dodecyl maltoside (DDM. They preserve the ATPase activity of BmrA (which resets the protein to its initial state after drug efflux much more efficiently than SDS (sodium dodecyl sulphate, FC12 (Foscholine 12 or DDM. They also maintain in a functional state the C4Cn-extracted protein upon detergent exchange with FC12. Finally, they promote 3D-crystallization of the membrane protein. CONCLUSION/SIGNIFICANCE: These compounds seem promising to extract in a functional state

  15. Processivity and collectivity of biomolecular motors extracting membrane nanotubes

    Science.gov (United States)

    Fontenele Araujo, Francisco; Storm, Cornelis

    2012-07-01

    Biomolecular motors can pull and viscously drag membranes. The resulting elongations include cell protrusions, tether networks, and sensorial tentacles. Here we focus on the extraction of a single tube from a vesicle. Via a force balance coupled to binding kinetics, we analytically determine the phase diagram of tube formation as function of the motor processivity, the surface viscosity of the membrane ηm', and the density of motors on the vesicle ρ. Three tubulation mechanisms are identified: (i) tip pulling, due to the accumulation of motors at the leading edge of the membrane, (ii) viscous drag, emergent from the translation of motors along the tube, and (iii) hybrid extraction, such that tip pulling and viscous drag are equally important. For experimental values of ηm' and ρ, we find that the growth of bionanotubes tends to be driven by viscous forces, whereas artificial membranes are dominated by tip pulling.

  16. One-step extraction of polar drugs from plasma by parallel artificial liquid membrane extraction.

    Science.gov (United States)

    Pilařová, Veronika; Sultani, Mumtaz; Ask, Kristine Skoglund; Nováková, Lucie; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2017-02-01

    The new microextraction technique named parallel artificial liquid membrane extraction (PALME) was introduced as an alternative approach to liquid-liquid extraction of charged analytes from aqueous samples. The concept is based on extraction of analytes across a supported liquid membrane sustained in the pores of a thin polymeric membrane, a well-known extraction principle also used in hollow fiber liquid-phase microextraction (HF-LPME). However, the new PALME technique offers a more user-friendly setup in which the supported liquid membrane is incorporated in a 96 well plate system. Thus, high-throughput is achievable, in addition to the green chemistry offered by using PALME. The consumption of organic solvent is minimized to 3-5μL per sample. With a sample volume of 250μL and acceptor solution volume of 50μL, a maximal enrichment factor of five is achievable. Based on these parameters, a new method for extraction of polar basic drugs was developed in the present work. The basic drugs hydralazine, ephedrine, metaraminol, salbutamol, and cimetidine were used as model analytes, and were extracted from alkalized human plasma into an aqueous solution via the supported liquid membrane. The extraction was promoted by a carrier dissolved in the membrane, creating a temporary ion-pair complex between the hydrophilic drug and the carrier. As the model analytes were extracted directly into an aqueous solution, there was no need for evaporation of the extract before injection into LC-MS. Hence, the sample preparation is performed in one step. With optimized conditions, the extraction recoveries were in the range 50-89% from human plasma after 45min extraction. The data from the method evaluation were satisfactory and in line with current guidelines, and revealed an extraction method with substantial potential for high throughput bioanalysis of polar basic drugs. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Review Paper on Cell Membrane Electroporation of Microalgae using Electric Field Treatment Method for Microalgae Lipid Extraction

    Science.gov (United States)

    Joannes, C.; Sipaut, C. S.; Dayou, J.; Yasir, S. M.; Mansa, R. F.

    2015-04-01

    The paper reviews the recent studies on the lipid extraction of microalgae that mainly highlighted on the cell disruption method using variety of microalgae species. Selection of cell disruption method and devices are crucial in order to achieve the highest extraction percentage of lipid and other valuable intracellular (proteins, carotenoids and chlorophylls) from microalgae cell. Pulsed electric field (PEF) and electrochemical lysis methods were found to be potential for enhancing the extraction efficiencies either conducted in single step extraction or used as pre-treatment followed by conventional extraction method. The PEF technology capable to extract lipid as high as 75%. While, electrochemical lysis treatment capable to extract lipid approximately 93% using Stainless Steel (SS) and Ti/IrO2 as the cathode and anode electrode respectively. PEF technology and electrochemical lysis are still considered to be a new method for microalgae lipid extraction and further investigation can still be done for better improvement of the system.

  18. Urea enhances cell lysis of Schizosaccharomyces pombe ura4 mutants.

    Science.gov (United States)

    Nishino, Kohei; Kushima, Misaki; Kaino, Tomohiro; Matsuo, Yasuhiro; Kawamukai, Makoto

    2017-07-01

    Cell lysis is induced in Schizosaccharomyces pombe ∆ura4 cells grown in YPD medium, which contains yeast extract, polypeptone, and glucose. To identify the medium components that induce cell lysis, we first tested various kinds of yeast extracts from different suppliers. Cell lysis of ∆ura4 cells on YE medium was observed when yeast extracts from OXOID, BD, Oriental, and Difco were used, but not when using yeast extract from Kyokuto. To determine which compounds induced cell lysis, we subjected yeast extract and polypeptone to GC-MS analysis. Ten kinds of compounds were detected in OXOID and BD yeast extracts, but not in Kyokuto yeast extract. Among them was urea, which was also present in polypeptone, and it clearly induced cell lysis. Deletion of the ure2 gene, which is responsible for utilizing urea, abolished the lytic effect of urea. The effect of urea was suppressed by deletion of pub1, and a similar phenotype was observed in the presence of polypeptone. Thus, urea is an inducer of cell lysis in S. pombe ∆ura4 cells.

  19. Preconcentration in micro-electromembrane extraction across free liquid membranes

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 848, Oct (2014), s. 43-50 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : free liquid membranes * micro-electromembrane extraction * preconcentration Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.513, year: 2014

  20. Supported liquid membrane extraction of 17ß- estradiol

    African Journals Online (AJOL)

    b- estradiol and its metabolites, namely 17b-estriol and estrone in various biological matrices and water. The biological matrices in which extraction was done included bovine kidney and liver tissues, milk and urine. The liquid membrane used to trap these compounds was made of 5% tri-n-octylphosphine oxide (TOPO) ...

  1. High-throughput liquid-liquid extraction in 96-well format: Parallel artificial liquid membrane extraction

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Andresen, Alf Terje; Dahlgren, Anders

    2017-01-01

    Parallel artificial liquid membrane extraction (PALME) is a miniaturized version of liquid–liquid extraction (LLE) and is based on two 96-well plates in a sandwich-like configuration. With a very simple workflow, 96 samples can be processed simultaneously in PALME, providing analyte enrichment...

  2. Extraction of Lactic Acid from Aqueous Feeds Using Membrane-Supported Reactive Extraction

    NARCIS (Netherlands)

    Gössi, A.; Riedl, Wolfgang; Schuur, B.

    Lactic acid extraction and back-extraction were studied using trioctylamine as reactive agent. Different hollow fiber and capillary membrane containing contactors with areas between 0.005 and 1.4 m2as well as various temperatures flow rates and phase ratios of up to 1:40 solvent/feed (S/F) were

  3. A Simple Method for DNA Extraction from Mature Date Palm Leaves: Impact of Sand Grinding and Composition of Lysis Buffer

    Directory of Open Access Journals (Sweden)

    Mohammad Al Sadoon

    2010-09-01

    Full Text Available Molecular marker techniques have been widely used for cultivar identification of inbred date palms (Phoenix dactylifera L.; Arecaceae and biodiversity conservation. Isolation of highly pure DNA is the prerequisite for PCR amplification and subsequent use such as DNA fingerprinting and sequencing of genes that have recently been developed for barcoding. To avoid problems related to the preservation and use of liquid nitrogen, we examined sterile sand for grinding the date palm leaves. Individual and combined effects of sodium chloride (NaCl, polyvinylpyrrolidone (PVP and lithium chloride (LiCl with the cetyltrimethylammonium bromide (CTAB method for a DNA yield of sufficient purity and PCR amplification were evaluated in this study. Presence of LiCl and PVP alone or together in the lysis buffer did not significantly improve the DNA yield and purity compared with the addition of NaCl. Our study suggested that grinding of date palm leaf with sterile sand and inclusion of NaCl (1.4 M in the lysis buffer without the costly use of liquid nitrogen, PVP and LiCl, provides a DNA yield of sufficient purity, suitable for PCR amplification.

  4. RED WINE EXTRACT OBTAINED BY MEMBRANE-BASED SUPERCRITICAL FLUID EXTRACTION: PRELIMINARY CHARACTERIZATION OF CHEMICAL PROPERTIES.

    Directory of Open Access Journals (Sweden)

    W. Silva

    Full Text Available ABSTRACT This study aims to obtain an extract from red wine by using membrane-based supercritical fluid extraction. This technique involves the use of porous membranes as contactors during the dense gas extraction process from liquid matrices. In this work, a Cabernet Sauvignon wine extract was obtained from supercritical fluid extraction using pressurized carbon dioxide as solvent and a hollow fiber contactor as extraction setup. The process was continuously conducted at pressures between 12 and 18 MPa and temperatures ranged from 30 to 50ºC. Meanwhile, flow rates of feed wine and supercritical CO2 varied from 0.1 to 0.5 mL min-1 and from 60 to 80 mL min-1 (NCPT, respectively. From extraction assays, the highest extraction percentage value obtained from the total amount of phenolic compounds was 14% in only one extraction step at 18MPa and 35ºC. A summarized chemical characterization of the obtained extract is reported in this work; one of the main compounds in this extract could be a low molecular weight organic acid with aromatic structure and methyl and carboxyl groups. Finally, this preliminary characterization of this extract shows a remarkable ORAC value equal to 101737 ± 5324 µmol Trolox equivalents (TE per 100 g of extract.

  5. Deacidification of Soybean Oil Combining Solvent Extraction and Membrane Technology

    Directory of Open Access Journals (Sweden)

    M. L. Fornasero

    2013-01-01

    Full Text Available The aim of this work was to study the removal of free fatty acids (FFAs from soybean oil, combining solvent extraction (liquid-liquid for the separation of FFAs from the oil and membrane technology to recover the solvent through nanofiltration (NF. Degummed soybean oil containing 1.05 ± 0.10% w/w FFAs was deacidified by extraction with ethanol. Results obtained in the experiences of FFAs extraction from oil show that the optimal operating conditions are the following: 1.8 : 1 w : w ethanol/oil ratio, 30 minutes extraction time and high speed of agitation and 30 minutes repose time after extraction at ambient temperature. As a result of these operations two phases are obtained: deacidified oil phase and ethanol phase (containing the FFAs. The oil from the first extraction is subjected to a second extraction under the same conditions, reducing the FFA concentration in oil to 0.09%. Solvent recovery from the ethanol phase is performed using nanofiltration technology with a commercially available polymeric NF membrane (NF-99-HF, Alfa Laval. From the analysis of the results we can conclude that the optimal operating conditions are pressure of 20 bar and temperature of 35°C, allowing better separation performance: permeate flux of 28.3 L/m2·h and FFA retention of 70%.

  6. Lysis from without

    Science.gov (United States)

    2011-01-01

    In this commentary I consider use of the term “lysis from without” (LO) along with the phenomenon's biological relevance. LO originally described an early bacterial lysis induced by high-multiplicity virion adsorption and that occurs without phage production (here indicated as LOV). Notably, this is more than just high phage multiplicities of adsorption leading to bacterial killing. The action on bacteria of exogenously supplied phage lysin, too, has been described as a form of LO (here, LOL). LOV has been somewhat worked out mechanistically for T4 phages, has been used to elucidate various phage-associated phenomena including discovery of the phage eclipse, may be relevant to phage ecology, and, with resistance to LO (LOR), is blocked by certain phage gene products. Speculation as to the impact of LOV on phage therapy also is fairly common. Since LOV assays are relatively easily performed and not all phages are able to induce LOV, a phage's potential to lyse bacteria without first infecting should be subject to at least in vitro experimental confirmation before the LOV label is applied. The term “abortive infection” may be used more generally to describe non-productive phage infections that kill bacteria. PMID:21687534

  7. Fluorescent method for monitoring cheese starter permeabilization and lysis

    NARCIS (Netherlands)

    Bunthof, C.J.; Schalkwijk, van S.; Meijer, W.; Abee, T.; Hugenholtz, J.

    2001-01-01

    A fluorescence method to monitor lysis of cheese starter bacteria using dual staining with the LIVE/DEAD BacLight bacterial viability kit is described. This kit combines membrane-permeant green fluorescent nucleic acid dye SYTO 9 and membrane-impermeant red fluorescent nucleic acid dye propidium

  8. One-step extraction of polar drugs from plasma by Parallel Artificial Liquid Membrane Extraction

    DEFF Research Database (Denmark)

    Pilařová, Veronika; Sultani, Mumtaz; Ask, Kristine Skoglund

    2017-01-01

    -throughput is achievable, in addition to the green chemistry offered by using PALME. The consumption of organic solvent is minimized to 3-5μL per sample. With a sample volume of 250μL and acceptor solution volume of 50μL, a maximal enrichment factor of five is achievable. Based on these parameters, a new method...... for extraction of polar basic drugs was developed in the present work. The basic drugs hydralazine, ephedrine, metaraminol, salbutamol, and cimetidine were used as model analytes, and were extracted from alkalized human plasma into an aqueous solution via the supported liquid membrane. The extraction...... was promoted by a carrier dissolved in the membrane, creating a temporary ion-pair complex between the hydrophilic drug and the carrier. As the model analytes were extracted directly into an aqueous solution, there was no need for evaporation of the extract before injection into LC-MS. Hence, the sample...

  9. Composite hollow fiber membranes for organic solvent-based liquid-liquid extraction

    NARCIS (Netherlands)

    He, T.; Bolhuis-Versteeg, Lydia A.M.; Mulder, M.H.V.; Wessling, Matthias

    2004-01-01

    Instability issues of liquid membranes extraction significantly limit its wide application in industry. We report research on the application of a new composite hollow fiber membrane to stabilizing liquid membrane extraction. These type of composite membranes have either a polysulfone (PSf)

  10. Selective Extraction of Rare Earth Elements from Permanent Magnet Scraps with Membrane Solvent Extraction.

    Science.gov (United States)

    Kim, Daejin; Powell, Lawrence E; Delmau, Lætitia H; Peterson, Eric S; Herchenroeder, Jim; Bhave, Ramesh R

    2015-08-18

    The rare earth elements (REEs) such as neodymium, praseodymium, and dysprosium were successfully recovered from commercial NdFeB magnets and industrial scrap magnets via membrane assisted solvent extraction (MSX). A hollow fiber membrane system was evaluated to extract REEs in a single step with the feed and strip solutions circulating continuously through the MSX system. The effects of several experimental variables on REE extraction such as flow rate, concentration of REEs in the feed solution, membrane configuration, and composition of acids were investigated with the MSX system. A multimembrane module configuration with REEs dissolved in aqueous nitric acid solutions showed high selectivity for REE extraction with no coextraction of non-REEs, whereas the use of aqueous hydrochloric acid solution resulted in coextraction of non-REEs due to the formation of chloroanions of non-REEs. The REE oxides were recovered from the strip solution through precipitation, drying, and annealing steps. The resulting REE oxides were characterized with XRD, SEM-EDX, and ICP-OES, demonstrating that the membrane assisted solvent extraction is capable of selectively recovering pure REEs from the industrial scrap magnets.

  11. Preconcentration in micro-electromembrane extraction across free liquid membranes.

    Science.gov (United States)

    Kubáň, Pavel; Boček, Petr

    2014-10-27

    Preconcentration potential of micro-electromembrane extraction (μ-EME) across free liquid membrane (FLM) was examined with an anionic and a cationic dye, 4,5-dihydroxy-3-(p-sulfophenylazo)-2,7-naphthalene disulfonic acid, trisodium salt (SPADNS) and phenosafranine, respectively. For the first time, it was shown that the spatial flexibility of FLMs enabled application of tailored extraction units with mutually different shapes and migration cross-sections for FLMs, donor and acceptor solutions. Thus, e.g. conical units enabled easy and reproducible formation of a three-phase extraction system (donor/FLM/acceptor) with sub-μL volumes of acceptor solutions as well as rapid and highly efficient preconcentration of the two dyes. Quantitative measurements of resulting solutions were carried out by UV-vis spectrophotometry and enrichment factors of up to 98 were achieved for μ-EMEs of 20 μM SPADNS (50 μL) preconcentrated into 0.5 μL of pure water across 1-pentanol at -150 V for 18 min. Visual monitoring of the entire extraction process (with USB microscope camera) was possible across transparent extraction units, moreover, important extraction parameters, such as FLM dimensions and donor-to-acceptor solution volume ratio, which determine the mechanical stability of the membrane and maximum enrichment factor, respectively, were readily adjusted. Combination of μ-EME across FLMs with capillary electrophoresis (CE) was further shown suitable for preconcentration and determination of perchlorate in drinking water samples. Good repeatability of the μ-EME-CE method (RSD values better than 9.5%), linear relationship for the analytical signal vs. concentration (r(2) better than 0.997) and enrichment factors of up to 30 were achieved for μ-EMEs of perchlorate across 1-pentanol and 1-hexanol based FLMs. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Extraction of nickel by liquid membranes in an electric field

    Energy Technology Data Exchange (ETDEWEB)

    Serga, V.E.; Kulikova, L.D.; Purin, B.A.

    2000-01-01

    The known liquid membranes (impregnated and emulsion) based on di-2-ethylhexylphosphoric acid (D2EHPA) extract nickel only out of weakly acid and neutral solutions. The authors have found that direct current applied to an extraction system contributes to the complete extraction of nickel cations (0.003--0.009 M NiSO{sub 4}) out of more acidic solutions (C{sub H{sub 2}SO{sub 4}} {le} 0.05 M) as well. The organic membrane phase is a D2EHPA solution (20 vol%) in 1,2-dichloroethane with 5--20 vol% of tributyl phosphate (I) or 1--2 vol% n-trioctylamine (II) added. These additions increase the electrical conductivity of the system 10--20 times. This allows for the extraction of nickel cations at optimal values of current density (for I: i {le} 2.1 mA/cm{sup 2}; for II: i {ge} 4.9 mA/cm{sup 2}). It is shown that the flow of nickel cations through the feed solution/organic phase interface increases with a certain increase of current density, metal content in the aqueous phase, and amount of addition of I or II in the studied concentration range. Chronopotentiograms can be used to estimate the efficiency of nickel extraction. If an electric field is applied, the transfer of nickel cations is codirected with that of hydrogen ions through the interface. Kinetic measurements of nickel cation as well as of hydrogen ion transport numbers revealed that the nickel cation extraction process was preceded by the transport of hydrogen ions through the feed solution/organic phase interface.

  13. Spontaneous Tumor Lysis Syndrome

    Directory of Open Access Journals (Sweden)

    Alicia C. Weeks MD

    2015-08-01

    Full Text Available Tumor lysis syndrome (TLS is a known complication of malignancy and its treatment. The incidence varies on malignancy type, but is most common with hematologic neoplasms during cytotoxic treatment. Spontaneous TLS is thought to be rare. This case study is of a 62-year-old female admitted with multisystem organ failure, with subsequent diagnosis of aggressive B cell lymphoma. On admission, laboratory abnormalities included renal failure, elevated uric acid (20.7 mg/dL, and 3+ amorphous urates on urinalysis. Oliguric renal failure persisted despite aggressive hydration and diuretic use, requiring initiation of hemodialysis prior to chemotherapy. Antihyperuricemic therapy and hemodialysis were used to resolve hyperuricemia. However, due to multisystem organ dysfunction syndrome with extremely poor prognosis, the patient ultimately expired in the setting of a terminal ventilator wean. Although our patient did not meet current TLS criteria, she required hemodialysis due to uric acid nephropathy, a complication of TLS. This poses the clinical question of whether adequate diagnostic criteria exist for spontaneous TLS and if the lack of currently accepted guidelines has resulted in the underestimation of its incidence. Allopurinol and rasburicase are commonly used for prevention and treatment of TLS. Although both drugs decrease uric acid levels, allopurinol mechanistically prevents formation of the substrate rasburicase acts to solubilize. These drugs were administered together in our patient, although no established guidelines recommend combined use. This raises the clinical question of whether combined therapy is truly beneficial or, conversely, detrimental to patient outcomes.

  14. Micro-electromembrane extraction across free liquid membranes. Extractions of basic drugs from undiluted biological samples

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 1337, Apr (2014), s. 32-39 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : micro-electromembrane extraction * free liquid membranes * biological samples Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  15. Micro-electromembrane extraction across free liquid membranes. Extractions of basic drugs from undiluted biological samples

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 1337, Apr (2014), s. 32-39 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : micro-electromembrane extraction * free liquid membranes * biological samples Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 4.169, year: 2014

  16. Research News: Emulsion Liquid Membrane Extraction in a Hollow-Fiber Contactor

    Science.gov (United States)

    Wiencek, John M.; Hu, Shih-Yao

    2000-01-01

    This article describes how ELMs (emulsion liquid membranes) can be used for extraction. The article addresses the disadvantages of ELM extraction in a stirred contactor, and the advantages of SELMs (supported emulsion liquid membranes). The introduction of the article provides background information on liquid-liquid solvent extraction and dispersion-free solvent extraction.

  17. A simple and rapid lysis method for preparation of genomic DNA ...

    African Journals Online (AJOL)

    Yomi

    2011-12-07

    Dec 7, 2011 ... extraction while improving the quality of extracted DNA. However, all the existing methods invariably involve two important steps: Cell lysis and precipitation of the DNA. The lysis step is performed with detergents, enzymes, or organic solvents and consuming a long time (Marmur,. 1961; Flamm et al., 1984; ...

  18. The Spanin Complex Is Essential for Lambda Lysis

    Science.gov (United States)

    Berry, Joel; Rajaure, Manoj; Pang, Ting

    2012-01-01

    Phage lysis is a ubiquitous biological process, the most frequent cytocidal event in the biosphere. Lysis of Gram-negative hosts has been shown to require holins and endolysins, which attack the cytoplasmic membrane and peptidoglycan, respectively. Recently, a third class of lysis proteins, the spanins, was identified. The first spanins to be characterized were λ Rz and Rz1, an integral cytoplasmic membrane protein and an outer membrane lipoprotein, respectively. Previous work has shown that Rz and Rz1 form complexes that span the entire periplasm. Phase-contrast video microscopy was used to record the morphological changes involved in the lysis of induced λ lysogens carrying prophages with either the λ canonical holin-endolysin system or the phage 21 pinholin-signal anchor release (SAR) endolysin system. In the former, rod morphology persisted until the instant of an explosive polar rupture, immediately emptying the cell of its contents. In contrast, in pinholin-SAR endolysin lysis, the cell began to shorten and thicken uniformly, with the resultant rounded cell finally bursting. In both cases, lysis failed to occur in inductions of isogenic prophages carrying null mutations in the spanin genes. In both systems, instead of an envelope rupture, the induced cells were converted from a rod shape to a spherical form. A functional GFPΦRz chimera was shown to exhibit a punctate distribution when coexpressed with Rz1, despite the absence of endolysin function. A model is proposed in which the spanins carry out the essential step of disrupting the outer membrane, in a manner regulated by the state of the peptidoglycan layer. PMID:22904283

  19. Fluorine NMR-based screening on cell membrane extracts.

    Science.gov (United States)

    Veronesi, Marina; Romeo, Elisa; Lambruschini, Chiara; Piomelli, Daniele; Bandiera, Tiziano; Scarpelli, Rita; Garau, Gianpiero; Dalvit, Claudio

    2014-02-01

    The possibility of measuring the action of inhibitors of specific enzymatic reactions in intact cells, cell lysates or membrane preparations represents a major advance in the lead discovery process. Despite the relevance of assaying in physiological conditions, only a small number of biophysical techniques, often requiring complex set-up, are applicable to these sample types. Here, we demonstrate the first application of n-fluorine atoms for biochemical screening (n-FABS), a homogeneous and versatile assay based on (19) F NMR spectroscopy, to the detection of high- and low-affinity inhibitors of a membrane enzyme in cell extracts and determination of their IC50 values. Our approach can allow the discovery of novel binding fragments against targets known to be difficult to purify or where membrane-association is required for activity. These results pave the way for future applications of the methodology to these relevant and complex biological systems. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. On-chip electro membrane extraction with online ultraviolet and mass spectrometric detection

    DEFF Research Database (Denmark)

    Petersen, Nickolaj Jacob; Foss, Sunniva Taule; Jensen, Henrik

    2011-01-01

    Electro membrane extraction was demonstrated in a microfluidic device. The device was composed of a 25 μm thick porous polypropylene membrane bonded between two poly(methyl methacrylate) (PMMA) substrates, each having 50 μm deep channel structures facing the membrane. The supported liquid membran...

  1. Phage lysis: three steps, three choices, one outcome

    Science.gov (United States)

    Young, Ry

    2014-01-01

    The lysis of bacterial hosts by double-strand DNA bacteriophages, once thought to reflect merely the accumulation of sufficient lysozyme activity during the infection cycle, has been revealed to recently been revealed to be a carefully regulated and temporally scheduled process. For phages of Gram-negative hosts, there are three steps, corresponding to subversion of each of the three layers of the cell envelope: inner membrane, peptidoglycan, and outer membrane. The pathway is controlled at the level of the cytoplasmic membrane. In canonical lysis, a phage encoded protein, the holin, accumulates harmlessly in the cytoplasmic membrane until triggering at an allele-specific time to form micron-scale holes. This allows the soluble endolysin to escape from the cytoplasm to degrade the peptidoglycan. Recently a parallel pathway has been elucidated in which a different type of holin, the pinholin, which, instead of triggering to form large holes, instead triggers to form small, heptameric channels that serve to depolarize the membrane. Pinholins are associated with SAR endolysins, which accumulate in the periplasm as inactive, membrane-tethered enzymes. Pinholin triggering collapses the proton motive force, allowing the SAR endolysins to refold to an active form and attack the peptidoglycan. Surprisingly, a third step, the disruption of the outer membrane is also required. This is usually achieved by a spanin complex, consisting of a small outer membrane lipoprotein and an integral cytoplasmic membrane protein, designated as o-spanins and i-spanins, respectively. Without spanin function, lysis is blocked and progeny virions are trapped in dead spherical cells, suggesting that the outer membrane has considerable tensile strength. In addition to two-component spanins, there are some single-component spanins, or u-spanins, that have an N-terminal outer-membrane lipoprotein signal and a C-terminal transmembrane domain. A possible mechanism for spanin function to disrupt the

  2. Defective lysis of streptomycin-resistant escherichia coli cells infected with bacteriophage f2.

    OpenAIRE

    De Mars Cody, J; Conway, T W

    1981-01-01

    A lysis defect was found to account for the failure of a streptomycin-resistant strain of Escherichia coli to form plaques when infected with the male-specific bacteriophage f2. The lysis defect was associated with the mutation to streptomycin resistance. Large amounts of apparently normal bacteriophage accumulated in these cells. Cell-free extracts from both the parental and mutant strains synthesized a potential lysis protein in considerable amounts in response to formaldehyde-treated f2 RN...

  3. Catalytic membrane reactor for tritium extraction system from He purge

    International Nuclear Information System (INIS)

    Santucci, Alessia; Incelli, Marco; Sansovini, Mirko; Tosti, Silvano

    2016-01-01

    Highlights: • In the HCBB blanket, the produced tritium is recovered by purging with helium; membrane technologies are able to separate tritium from helium. • The paper presents the results of two experimental campaigns. • In the first, a Pd–Ag diffuser for hydrogen separation is tested at several operating conditions. • In the second, the ability of a Pd–Ag membrane reactor for water decontamination is assessed by performing isotopic swamping and water gas shift reactions. - Abstract: In the Helium Cooled Pebble Bed (HCPB) blanket concept, the produced tritium is recovered purging the breeder with helium at low pressure, thus a tritium extraction system (TES) is foreseen to separate the produced tritium (which contains impurities like water) from the helium gas purge. Several R&D activities are running in parallel to experimentally identify most promising TES technologies: particularly, Pd-based membrane reactors (MR) are under investigation because of their large hydrogen selectivity, continuous operation capability, reliability and compactness. The construction and operation under DEMO relevant conditions (that presently foresee a He purge flow rate of about 10,000 Nm 3 /h and a H 2 /He ratio of 0.1%) of a medium scale MR is scheduled for next year, while presently preliminary experiments on a small scale reactor are performed to identify most suitable operative conditions and catalyst materials. This work presents the results of an experimental campaign carried out on a Pd-based membrane aimed at measuring the capability of this device in separating hydrogen from the helium. Many operative conditions have been investigated by considering different He/H 2 feed flow ratios, several lumen pressures and reactor temperatures. Moreover, the performances of a membrane reactor (composed of a Pd–Ag tube having a wall thickness of about 113 μm, length 500 mm and diameter 10 mm) in processing the water contained in the purge gas have been measured by using

  4. Catalytic membrane reactor for tritium extraction system from He purge

    Energy Technology Data Exchange (ETDEWEB)

    Santucci, Alessia, E-mail: alessia.santucci@enea.it [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Incelli, Marco [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy); DEIM, University of Tuscia, Via del Paradiso 47, 01100 Viterbo (Italy); Sansovini, Mirko; Tosti, Silvano [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy)

    2016-11-01

    Highlights: • In the HCBB blanket, the produced tritium is recovered by purging with helium; membrane technologies are able to separate tritium from helium. • The paper presents the results of two experimental campaigns. • In the first, a Pd–Ag diffuser for hydrogen separation is tested at several operating conditions. • In the second, the ability of a Pd–Ag membrane reactor for water decontamination is assessed by performing isotopic swamping and water gas shift reactions. - Abstract: In the Helium Cooled Pebble Bed (HCPB) blanket concept, the produced tritium is recovered purging the breeder with helium at low pressure, thus a tritium extraction system (TES) is foreseen to separate the produced tritium (which contains impurities like water) from the helium gas purge. Several R&D activities are running in parallel to experimentally identify most promising TES technologies: particularly, Pd-based membrane reactors (MR) are under investigation because of their large hydrogen selectivity, continuous operation capability, reliability and compactness. The construction and operation under DEMO relevant conditions (that presently foresee a He purge flow rate of about 10,000 Nm{sup 3}/h and a H{sub 2}/He ratio of 0.1%) of a medium scale MR is scheduled for next year, while presently preliminary experiments on a small scale reactor are performed to identify most suitable operative conditions and catalyst materials. This work presents the results of an experimental campaign carried out on a Pd-based membrane aimed at measuring the capability of this device in separating hydrogen from the helium. Many operative conditions have been investigated by considering different He/H{sub 2} feed flow ratios, several lumen pressures and reactor temperatures. Moreover, the performances of a membrane reactor (composed of a Pd–Ag tube having a wall thickness of about 113 μm, length 500 mm and diameter 10 mm) in processing the water contained in the purge gas have been

  5. Antifungal Extraction by the Extracorporeal Membrane Oxygenation Circuit.

    Science.gov (United States)

    Watt, Kevin M; Cohen-Wolkowiez, Michael; Williams, Duane C; Bonadonna, Desiree K; Cheifetz, Ira M; Thakker, Dhiren; Benjamin, Daniel K; Brouwer, Kim L R

    2017-09-01

    Invasive candidiasis is common and often fatal in patients supported with extracorporeal membrane oxygenation (ECMO), and treatment relies on optimal antifungal dosing. The ECMO circuit can extract drug and decrease drug exposure, placing the patient at risk of therapeutic failure. This ex vivo study determined the extraction of antifungal drugs by the ECMO circuit. Fluconazole and micafungin were studied separately in three closed-loop circuit configurations to isolate the impact of the oxygenator, hemofilter, and tubing on circuit extraction. Each circuit was primed with human blood, and flow was set to 1 L/min. Drug was dosed to achieve therapeutic concentrations. Each antifungal was added to a separate tube of blood to serve as a control. Serial blood samples were collected over 24 hours and concentrations were quantified with a validated assay. Drug recovery was calculated at each time point: (C t /C i )*100, with C t and C i the concentrations at time = t and 1 minute, respectively. After 24 hours of recirculation, mean recovery of fluconazole in the ECMO circuit (95-98%) and controls (101%) was high. In contrast, mean recovery of micafungin was dependent on the time and circuit configuration. Recovery at 4 hours was only 46% when a hemofilter was in-line but was much higher when the hemofilter was removed (91%). By 24 hours, however, micafungin recovery was low in all circuit configurations (26-43%), regardless of the presence of a hemofilter, as well as in the controls (57%). In conclusion, these results suggest that micafungin is extracted by the ECMO circuit, which may result in decreased drug exposure in vivo.

  6. Tumor lysis syndrome in children

    International Nuclear Information System (INIS)

    Suarez, Amaranto

    2004-01-01

    Tumor lysis syndrome is a metabolic emergency characterized by electrolyte alteration with or without acute renal failure. It occurs mainly in patients with malignant tumors that have a high growth fraction, or after cytotoxic therapy, as a result of the massive degradation of malignant cells and the release of high amounts of intracellular elements that exceed the capacity of renal excretion. The objective of the treatment is the prevention of nephropathy due to uric acid deposits, and the correction of metabolic acidosis and electrolyte alterations. This paper reviews the incidence, the physiopathology, and the treatment of tumor lysis syndrome in children

  7. Uranium Extraction From Artificial Liquid Waste Using Continuous Extraction Liquid membrane Technique

    International Nuclear Information System (INIS)

    Rusdianasari; Buchari

    2002-01-01

    The continuous extraction of uranium from artificial liquid waste by emulsion liquid membrane was carried out using one stage mixer-settler. This emulsion liquid membrane containing di-2-ethylhexylphosphoric acid (D2EHPA) and tri-n-buthyl phosphate (TBP) as carrier were carried out using one stage mixer-settler. The optimum condition gave the ratio of emulsion velocity to the feed velocity 1:4 and steady state reached after five minutes. The optimum condition was obtained at the 90.91 % of uranium recovered from raffinate, using EDTA as the masking agent with concentration 5x10 - 2 M . The total concentration of carrier was 3% with ratio D2EHPA and TBP 3:1. The emulsion liquid membrane has high relative selectivity after steady state with separation factors were α U , N i= 115,43 and α U , Fe 328,55. The result of experiment showed that emulsion liquid membrane containing D2EHPA and TBP as carrier have good performance for continuous system

  8. Comparison of Different Sample Preparation Protocols Reveals Lysis Buffer-Specific Extraction Biases in Gram-Negative Bacteria and Human Cells.

    Science.gov (United States)

    Glatter, Timo; Ahrné, Erik; Schmidt, Alexander

    2015-11-06

    We evaluated different in-solution and FASP-based sample preparation strategies for absolute protein quantification. Label-free quantification (LFQ) was employed to compare different sample preparation strategies in the bacterium Pseudomonas aeruginosa and human embryonic kidney cells (HEK), and organismal-specific differences in general performance and enrichment of specific protein classes were noted. The original FASP protocol globally enriched for most proteins in the bacterial sample, whereas the sodium deoxycholate in-solution strategy was more efficient with HEK cells. Although detergents were found to be highly suited for global proteome analysis, higher intensities were obtained for high-abundant nucleic acid-associated protein complexes, like the ribosome and histone proteins, using guanidine hydrochloride. Importantly, we show for the first time that the observable total proteome mass of a sample strongly depends on the sample preparation protocol, with some protocols resulting in a significant underestimation of protein mass due to incomplete protein extraction of biased protein groups. Furthermore, we demonstrate that some of the observed abundance biases can be overcome by incorporating a nuclease treatment step or, alternatively, a correction factor for complementary sample preparation approaches.

  9. A synthetic peptide corresponding to the C-terminal 25 residues of phage MS2 coded lysis protein dissipates the protonmotive force in Escherichia coli membrane vesicles by generating hydrophilic pores

    NARCIS (Netherlands)

    Goessens, Wil H.F.; Driessen, Arnold J.M.; Wilschut, Jan; Duin, Jan van

    1988-01-01

    The RNA phage MS2 encodes a protein, 75 amino acids long, that is necessary and sufficient for lysis of the host cell. DNA deletion analysis has shown that the lytic activity is confined to the C-terminal half of the protein. We have examined the effects of a synthetic peptide, covering the

  10. Models of dynamic extraction of lipid tethers from cell membranes

    International Nuclear Information System (INIS)

    Nowak, Sarah A; Chou, Tom

    2010-01-01

    When a ligand that is bound to an integral membrane receptor is pulled, the membrane and the underlying cytoskeleton can deform before either the membrane delaminates from the cytoskeleton or the ligand detaches from the receptor. If the membrane delaminates from the cytoskeleton, it may be further extruded and form a membrane tether. We develop a phenomenological model for this process by assuming that deformations obey Hooke's law up to a critical force at which the cell membrane locally detaches from the cytoskeleton and a membrane tether forms. We compute the probability of tether formation and show that tethers can be extruded only within an intermediate range of force loading rates and pulling velocities. The mean tether length that arises at the moment of ligand detachment is computed as are the force loading rates and pulling velocities that yield the longest tethers

  11. Extracts of Edible and Medicinal Plants Damage Membranes of Vibrio cholerae▿

    Science.gov (United States)

    Sánchez, Eduardo; García, Santos; Heredia, Norma

    2010-01-01

    The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity, membrane potential, internal pH (pHin), and ATP synthesis were measured in Vibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts showing high antimicrobial activity. Our results indicate that methanolic extracts of basil (Ocimum basilicum L.), nopal cactus (Opuntia ficus-indica var. Villanueva L.), sweet acacia (Acacia farnesiana L.), and white sagebrush (Artemisia ludoviciana Nutt.) are the most active against V. cholera, with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives to control V. cholerae contamination in foods and the diseases associated with this microorganism. PMID:20802077

  12. Extracts of edible and medicinal plants damage membranes of Vibrio cholerae.

    Science.gov (United States)

    Sánchez, Eduardo; García, Santos; Heredia, Norma

    2010-10-01

    The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity, membrane potential, internal pH (pH(in)), and ATP synthesis were measured in Vibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts showing high antimicrobial activity. Our results indicate that methanolic extracts of basil (Ocimum basilicum L.), nopal cactus (Opuntia ficus-indica var. Villanueva L.), sweet acacia (Acacia farnesiana L.), and white sagebrush (Artemisia ludoviciana Nutt.) are the most active against V. cholera, with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives to control V. cholerae contamination in foods and the diseases associated with this microorganism.

  13. Reagentless mechanical cell lysis by nanoscale barbs in microchannels for sample preparation.

    Science.gov (United States)

    Di Carlo, Dino; Jeong, Ki-Hun; Lee, Luke P

    2003-11-01

    A highly effective, reagentless, mechanical cell lysis device integrated in microfluidic channels is reported. Sample preparation, specifically cell lysis, is a critical element in 'lab-on-chip' applications. However, traditional methods of cell lysis require purification steps or complicated fabrication steps that a simple mechanical method of lysis may avoid. A simple and effective mechanical cell lysis system is designed, microfabricated, and characterized to quantify the efficiency of cell lysis and biomolecule accessibility. The device functionality is based on a microfluidic filter region with nanostructured barbs created using a modified deep reactive ion etching process. Mechanical lysis is characterized by using a membrane impermeable dye. Three main mechanisms of micro-mechanical lysis are described. Quantitative measurements of accessible protein as compared to a chemically lysed sample are acquired with optical absorption measurements at 280 and 414 nm. At a flow rate of 300 microL min(-1) within the filter region total protein and hemoglobin accessibilities of 4.8% and 7.5% are observed respectively as compared to 1.9% and 3.2% for a filter without nanostructured barbs.

  14. Fractionation of hydro-ethanolic extracts from grape pomace through membrane processing: the effect of membrane and extracting media on process performance

    OpenAIRE

    Taqui, Syed Usman

    2014-01-01

    The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centers and universities Grape pomace are generated as waste in juice and winemaking industry in huge quantities. Studies have shown that nutrient extracts from these particular plant matrices garner myriad of benefits in health and nutraceuticals sector. Moreover,...

  15. Biological Activity of Blackcurrant Extracts (Ribes nigrum L. in Relation to Erythrocyte Membranes

    Directory of Open Access Journals (Sweden)

    Dorota Bonarska-Kujawa

    2014-01-01

    Full Text Available Compounds contained in fruits and leaves of blackcurrant (Ribes nigrum L. are known as agents acting preventively and therapeutically on the organism. The HPLC analysis showed they are rich in polyphenol anthocyanins in fruits and flavonoids in leaves, that have antioxidant activity and are beneficial for health. The aim of the research was to determine the effect of blackcurrant fruit and leaf extracts on the physical properties of the erythrocyte membranes and assess their antioxidant properties. The effect of the extracts on osmotic resistance, shape of erythrocytes and hemolytic and antioxidant activity of the extracts were examined with spectrophotometric methods. The FTIR investigation showed that extracts modify the erythrocyte membrane and protect it against free radicals induced by UV radiation. The results show that the extracts do not induce hemolysis and even protect erythrocytes against the harmful action of UVC radiation, while slightly strengthening the membrane and inducing echinocytes. The compounds contained in the extracts do not penetrate into the hydrophobic region, but bind to the membrane surface inducing small changes in the packing arrangement of the polar head groups of membrane lipids. The extracts have a high antioxidant activity. Their presence on the surface of the erythrocyte membrane entails protection against free radicals.

  16. Lactic acid Production with in situ Extraction in Membrane Bioreactor

    Directory of Open Access Journals (Sweden)

    Hamidreza Ghafouri Taleghani

    2017-01-01

    Full Text Available Background and Objective: Lactic acid is widely used in the food, chemical and pharmaceutical industries. The major problems associated with lactic acid production are substrate and end-product inhibition, and by-product formation. Membrane technologyrepresents one of the most effective processes for lactic acid production. The aim of this work is to increase cell density and lactic acid productivity due to reduced inhibition effect of substrate and product in membrane bioreactor.Material and Methods: In this work, lactic acid was produced from lactose in membrane bioreactor. A laboratory scale membrane bioreactor was designed and fabricated. Five types of commercial membranes were tested at the same operating conditions (transmembrane pressure: 500 KPa and temperature: 25°C. The effects of initial lactose concentration and dilution rate on biomass growth, lactic acid production and substrate utilization were evaluated.Results and Conclusion: The high lactose retention of 79% v v-1 and low lactic acid retention of 22% v v-1 were obtained with NF1 membrane; therefore, this membrane was selected for membrane bioreactor. The maximal productivity of 17.1 g l-1 h-1 was obtainedwith the lactic acid concentration of 71.5 g l-1 at the dilution rate of 0.24 h−1. The maximum concentration of lactic acid was obtained at the dilution rate of 0.04 h−1. The inhibiting effect of lactic acid was not observed at high initial lactose concentration. The critical lactose concentration at which the cell growth severely hampered was 150 g l-1. This study proved that membrane bioreactor had great advantages such as elimination of substrate and product inhibition, high concentration of process substrate, high cell density,and high lactic acid productivity.Conflict of interest: There is no conflict of interest.

  17. Molecular dynamics simulations of the interactions of medicinal plant extracts and drugs with lipid bilayer membranes

    DEFF Research Database (Denmark)

    Kopec, Wojciech; Telenius, Jelena; Khandelia, Himanshu

    2013-01-01

    Several small drugs and medicinal plant extracts, such as the Indian spice extract curcumin, have a wide range of useful pharmacological properties that cannot be ascribed to binding to a single protein target alone. The lipid bilayer membrane is thought to mediate the effects of many such molecu......Several small drugs and medicinal plant extracts, such as the Indian spice extract curcumin, have a wide range of useful pharmacological properties that cannot be ascribed to binding to a single protein target alone. The lipid bilayer membrane is thought to mediate the effects of many...

  18. Possible applications of crown-ethers to metal extraction using liquid membrane technology - a literature survey

    International Nuclear Information System (INIS)

    Dozol, M.

    1990-01-01

    Ether-crowns, discovered in 1967 by J.C. PEDERSEN, exhibit attractive complexive and extractive properties, enhanced in various fields, such as analytical chemistry, chemical synthesis, field of biology, or extractive chemistry. The investigations carried out on these macrocyclic compounds are continually increasing, as show in international literature. Among the focus of interest, the applications to metal extraction are extensively studied with crown compounds present in liquid phase or impregnated on supports (membranes or resins). The goal of this paper is to describe the application of crown-ethers to metal extraction, using liquid membrane processes. 69 refs

  19. Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

    OpenAIRE

    Siekierka Anna; Bryjak Marek

    2017-01-01

    Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity an...

  20. Synthesis of zeolite NaA membrane from fused fly ash extract

    CSIR Research Space (South Africa)

    Ameh, AE

    2016-01-01

    Full Text Available Zeolite-NaA membranes were synthesized from an extract of fused South African fly ash on a porous titanium support by a secondary growth method. The influence of the synthesis molar regime on the formation of zeolite NaA membrane layer...

  1. Removal of H2S and volatile organic sulfur compounds by silicone membrane extraction

    NARCIS (Netherlands)

    Manconi, I.; Lens, P.N.L.

    2009-01-01

    BACKGROUND: This study explores an alternative process for the abatement and/or desulfurization of H2S and volatile organic sulfur compounds (VOSC) containing waste streams, which employs a silicone-based membrane to simultaneously remove H2S and VOSC. An extractive membrane reactor allows the

  2. Development of a flat membrane based device for electromembrane extraction

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Eibak, Lars Erik Eng; Gjelstad, Astrid

    2014-01-01

    this EME device, exhaustive extraction of the basic drugs quetiapine, citalopram, amitriptyline, methadone and sertraline was investigated from both acidified water samples and human plasma. The volume of acceptor solution, extraction time, and extraction voltage were found to be important factors...

  3. Extraction of lithium ion from alkaline aqueous media by a liquid surfactant membrane

    International Nuclear Information System (INIS)

    Kinugasa, Takumi; Ono, Yuri; Kawamura, Yuko; Watanabe, Kunio; Takeuchi, Hiroshi.

    1995-01-01

    Extraction of lithium ion from aqueous alkaline media by a liquid surfactant membrane was performed using a mixture of LIX54 and TOPO as the extractant. Stripping of lithium from the kerosene solution to the acid solution was suppressed with increasing content of polyamine (ECA) surfactant. The extraction rate of lithium by the liquid membrane could be interpreted taking account of an interfacial resistance due to ECA. It was confirmed that swelling of the (W/O) emulsion drops by water permeation through the liquid membrane is evaluated in terms of a change in osmotic pressure gradient between the external and internal aqueous phases during the lithium extraction. In the present operation, the extraction ratio of Li + from the external feed and the uptake into the internal phase reached as high as 95%. (author)

  4. Parallel artificial liquid membrane extraction of psychoactive analytes: a novel approach in therapeutic drug monitoring.

    Science.gov (United States)

    Olsen, Katharina Norgren; Ask, Kristine Skoglund; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2018-03-01

    Liquid-liquid extraction is widely used in therapeutic drug monitoring of antipsychotics, but difficulties in automation of the technique can result in long operational time. In this paper, parallel artificial liquid membrane extraction was used for extraction of serotonin- and serotonin-norepinephrine reuptake inhibitors from human plasma, and an approach to automate the technique was investigated. Eight model analytes were extracted from 125 μl human plasma with recoveries in the range 72-111% (relative standard deviation [RSD] ≤12.8%). A semiautomated pipettor was successfully utilized in the procedure, reducing the manual handling time. Real patient samples were analyzed with satisfying accuracy. A semiautomated extraction of serotonin-and serotonin-norepinephrine reuptake inhibitors by parallel artificial liquid membrane extraction extraction was successfully performed.

  5. Lysis of bacterial cells in the process of bacteriophage release – canonical and newly discovered mechanisms

    Directory of Open Access Journals (Sweden)

    Wioleta M. Woźnica

    2015-01-01

    Full Text Available The release of phage progeny from an infected bacterium is necessary for the spread of infection. Only helical phages are secreted from a cell without causing its destruction. The release of remaining phages is correlated with bacterial lysis and death. Thus, the understanding of phage lytic functions is crucial for their use in the fight with bacterial pathogens. Bacteriophages with small RNA or DNA genomes encode single proteins which are called amurins and cause lysis by the inhibition of cell wall synthesis. Bacteriophages of double-stranded DNA genomes, which dominate in the environment, encode enzymes that are called endolysins and contribute to lysis by the cleavage of cell wall peptydoglycan. Endolysins that do not contain signal sequences cannot pass the cytoplasmic membrane by themselves. Their access to peptidoglycan is provided by membrane proteins – holins, which can form in the membrane large pores, that are called “holes”. Some endolysins do not require holins for their transport, owing to the presence of the so called SAR sequence at their N-terminus. It enables their transport through the membrane by the bacterial sec system. However, it is not cleaved off, and thus these endolysins remain trapped in the membrane in an inactive form. Their release, which is correlated with the activation, occurs as a result of membrane depolarization and depends on proteins that are called pinholins. Pinholins form in membrane pores that are too small for the passage of endolysins but sufficient for membrane depolarization. Proteins that are called antiholins regulate the timing of lysis, through the blockage of holins action until the end of phage morphogenesis. Additionally, newly identified lytic proteins, spanins, participate in the release of progeny phages from Gram-negative bacteria cells. They cause the destruction of outer cell membrane by its spanning with the cytoplasmic membrane. This is possible after the endolysin

  6. USE OF MEMBRANE EMULSION SPAN 80 AND TOPO IN URANIUM EXTRACTION AND STRIPPING

    Directory of Open Access Journals (Sweden)

    Kris Tri Basuki

    2017-01-01

    Full Text Available ABSTRACT USE OF MEMBRANE EMULSION SPAN 80 AND TOPO IN URANIUM EXTRACTION AND STRIPPING. Membrane emulsion span 80 and TOPO used in uranium extraction and stripping has been done. The extraction was carried outby emulsion membrane H3PO4 in TOPO-Kerosene. The feed or external aqueous phase was uranium in  HNO3. The emulgator span-80 was used to obtain a stable emulsion membrane system. The influence factors were percentage of TOPO-Kerosene, time extraction,  molarity of external aqueous phase and  molarity of internal aqueous. After the emulsion membrane was formed, the extractionand stripping process was performed. The ratio volume feed : volume membrane phase equal to 1 : 1 and volume of 5 % TOPO-Kerosene : Volume 3 M H3PO4 equal 1 : 1 were used. The relative good yield were obtained at concentration of TOPO in Kerosene and 3 M H3PO4 was 5 %, molarity of internal aqueous phase equal to 1 M, molarity of external aqueous phase 3 M H3PO4 and time extraction equalto 10 minutes with the speed of emulsification was 8000 rpm. At this condition the extraction efficiency of uranium obtained was 97.8 %, the stripping efficiency 52.56 %, and the total efficiency was 53.80 %. Keywords: membrane emulsion, extraction, stripping, span 80, kerosene, uranium. ABSTRAK PENGGUNAAN MEMBRAN EMULSI SPAN 80 DAN TOPO UNTUK EKSTRASI DAN STRIPPING URANIUM. Telah dilakukan penelitian membran emulsi span 80 dan TOPO yang digunakan untuk ekstraksi uranium. Extraksi dengan membran emulsi H3PO4 dalam TOPO-Kerosen. Larutan umpan untuk fasa air eksternal adalah uranium dalam asam nitrat. Untuk memperoleh sistem emulsi yang stabil dipakai emulgator Span 80. Parameter yang berpengaruh adalah persen TOPO-Kerosene, molaritas fasa air internal H3PO4, molaritas fasa air eksternal HNO3 dan waktu ekstraksi. Setelah diperoleh membran emulsi, kemudian dilakukan proses ekstraksi dan stripping, dengan rasio volume umpan : volume membran sebesar 1 : 1; volume 5% TOPO-Kerose : volume 3M

  7. Uranium extraction process in a sulfuric medium by means of liquid emulsified membranes

    International Nuclear Information System (INIS)

    Monteillet, A.

    1985-02-01

    Uranium ore processing, after leaching by sulfuric acid, by liquid-liquid extraction is a rather heavy process, not suitable for small deposits. Extraction by emulsions was suggested. In this process the leachate is contacted with an oil in water type emulsion, a liquid organic membrane is formed by the continuous phase. Uranium complexes diffuse through the liquid membrane towards the dispersed aqueous phase of the emulsion (stripping solution). Uranium is recovered by breaking the emulsion. Are successively studied: development of stable emulsions, influence of emulsion composition on uranium transfer kinetics, transfer mechanisms through the membrane and modelling of kinetics data obtained in the experimental study [fr

  8. Removal of VOCs from groundwater using membrane-assisted solvent extraction

    International Nuclear Information System (INIS)

    Hutter, J.C.; Vandegrift, G.F.; Nunez, L.; Redfield, D.H.

    1992-01-01

    A membrane-assisted solvent extraction (MASX) system coupled to a membrane-assisted distillation stripping (MADS) system for use in decontaminating groundwater is discussed. Volatile organic compounds (VOCs) are extracted in the MASX using a sunflower oil solvent. In the MADS, VOCs are stripped from the sunflower oil, and the oil is recycled to the MASX. Thermodynamic data for the sunflower oil-water-VOCs system were experimentally collected. Published membrane-mass transfer results along with these data were used to design the MASX and MADS modules

  9. Removal of VOCs from groundwater using membrane-assisted solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, J.C.; Vandegrift, G.F.; Nunez, L.; Redfield, D.H.

    1992-01-01

    A membrane-assisted solvent extraction (MASX) system coupled to a membrane-assisted distillation stripping (MADS) system for use in decontaminating groundwater is discussed. Volatile organic compounds (VOCs) are extracted in the MASX using a sunflower oil solvent. In the MADS, VOCs are stripped from the sunflower oil, and the oil is recycled to the MASX. Thermodynamic data for the sunflower oil-water-VOCs system were experimentally collected. Published membrane-mass transfer results along with these data were used to design the MASX and MADS modules.

  10. Removal of VOCs from groundwater using membrane-assisted solvent extraction

    Energy Technology Data Exchange (ETDEWEB)

    Hutter, J.C.; Vandegrift, G.F.; Nunez, L.; Redfield, D.H.

    1992-11-01

    A membrane-assisted solvent extraction (MASX) system coupled to a membrane-assisted distillation stripping (MADS) system for use in decontaminating groundwater is discussed. Volatile organic compounds (VOCs) are extracted in the MASX using a sunflower oil solvent. In the MADS, VOCs are stripped from the sunflower oil, and the oil is recycled to the MASX. Thermodynamic data for the sunflower oil-water-VOCs system were experimentally collected. Published membrane-mass transfer results along with these data were used to design the MASX and MADS modules.

  11. The extraction of uranium from wet process phosphoric acid using a liquid surfactant membrane system

    International Nuclear Information System (INIS)

    Dickens, N.; Davies, G.A.

    1984-01-01

    A liquid membrane extraction process is examined for the extraction of uranium from wet process phosphoric acid. Uranium is present in the acid in concentrations up to 100 ppm which in principle makes it ideal for treatment with a membrane process. The membrane system studied is based on extraction using DEHPA-TOPO reagents which are contained within the organic phase of a water in oil emulsion. Formulations of the emulsion membrane system have been studied, the limitations of acid temperature, P 2 O 5 concentration and solid dispersed impurities in the acid have been studied in laboratory batch experiments and in a continuous pilot plant unit capable of treating 5l of concentrated acid per minute. Data from the pilot plant work has been used to develop a flowsheet for a commercial unit based on this process. (author)

  12. Parallel artificial liquid membrane extraction of acidic drugs from human plasma

    DEFF Research Database (Denmark)

    Roldan-Pijuan, Mercedes; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2015-01-01

    The new sample preparation concept “Parallel artificial liquid membrane extraction (PALME)” was evaluated for extraction of the acidic drugs ketoprofen, fenoprofen, diclofenac, flurbiprofen, ibuprofen, and gemfibrozil from human plasma samples. Plasma samples (250 μL) were loaded into individual...

  13. Parallel artificial liquid membrane extraction of new psychoactive substances in plasma and whole blood

    DEFF Research Database (Denmark)

    Vårdal, Linda; Askildsen, Hilde-Merete; Gjelstad, Astrid

    2017-01-01

    Parallel artificial liquid membrane extraction (PALME) was combined with ultra-high performance liquid chromatography-mass spectrometry (UHPLC–MS) and the potential for screening of new psychoactive substances (NPS) was investigated for the first time. PALME was performed in 96-well format compri......, accuracy, extraction recoveries, carry-over, and matrix effects. The validation results were in accordance with FDA guidelines....

  14. Removal of acetic acid from simulated hemicellulosic hydrolysates by emulsion liquid membrane with organophosphorus extractants.

    Science.gov (United States)

    Lee, Sang Cheol

    2015-09-01

    Selective removal of acetic acid from simulated hemicellulosic hydrolysates containing xylose and sulfuric acid was attempted in a batch emulsion liquid membrane (ELM) system with organophosphorus extractants. Various experimental variables were used to develop a more energy-efficient ELM process. Total operation time of an ELM run with a very small quantity of trioctylphosphine oxide as the extractant was reduced to about a third of those required to attain almost the same extraction efficiency as obtained in previous ELM works without any extractant. Under specific conditions, acetic acid was selectively separated with a high degree of extraction and insignificant loss of xylose, and its purity and enrichment ratio in the stripping phase were higher than 92% and 6, respectively. Also, reused organic membrane solutions exhibited the extraction efficiency as high as fresh organic solutions did. These results showed that the current ELM process would be quite practical. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Liquid-liquid extraction of uranium(VI) in the system with a membrane contactor.

    Science.gov (United States)

    Biełuszka, Paweł; Zakrzewska, Grażyna; Chajduk, Ewelina; Dudek, Jakub

    Raising role of the nuclear power industry, including governmental plans for the construction of first nuclear power plant in Poland, creates increasing demand for the uranium-based nuclear fuels. The project implemented by Institute of Nuclear Chemistry and Technology concerns the development of effective methods for uranium extraction from low-grade ores and phosphorites for production of yellow cake-U 3 O 8 . The Liqui-Cel ® Extra-Flow 2.5 × 8 Membrane Contactor produced by CELGARD LLC (Charlotte, NC) company is the main component of the installation for liquid-liquid extraction applied for processing of post leaching liquors. In the process of membrane extraction the uranyl ions from aqueous phase are transported through the membrane into organic phase. The flow of two phases in the system was arranged in co-current mode. The very important element of the work was a selection of extracting agents appropriate for the membrane process. After preliminary experiments comprising tests of membrane resistivity and determination of extraction efficiency, di(2-ethylhexyl)phosphoric acid was found to be most favourable. An important aspect of the work was the adjustment of hydrodynamic conditions in the capillary module. To avoid the membrane wettability by organic solvent and mixing two phases equal pressure drops along the membrane module to minimize the transmembrane pressure, were assumed. Determination of pressure drop along the module was conducted using Bernoulli equation. The integrated process of extraction/re-extraction conducted in continuous mode with application of two contactors was designed.

  16. Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

    International Nuclear Information System (INIS)

    Mokhtari, Bahram; Pourabdollah, Kobra

    2013-01-01

    The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pentanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%

  17. Emulsion liquid membrane for selective extraction of bismuth from nitrate medium

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtari, Bahram; Pourabdollah, Kobra [Islamic Azad University, Shahreza (Iran, Islamic Republic of)

    2013-07-15

    The novelty of this work is the selective extraction of bismuth ions from nitrate medium by emulsion liquid membrane. Di(2-ethylhexyl)phosphoric acid was used as extractant of bismuth ions from nitrate medium by emulsion liquid membrane, and Triton X-100 was used as the biodegradable surfactant in n-pentanol n-pentanol bulk membrane. The extraction of bismuth ions was evaluated by the yield of extraction. The experimental parameters were evaluated and were optimized. They included the ratio of di(2-ethylhexyl)phosphoric acid concentration to the concentration of /Triton X-100 concentration (1.0 : 0.5% w/w), nature of diluents (n-pentanol), nature and concentration of the stripping solution (sulfuric acid, 0.5M), stirring speed (1,800 rpm) and equilibrium time of extraction (20min), initial feed solution of bismuth (350 ppm) and the volume ratio of the internal stripping phase to the membrane phase (14 times). The experimental parameters of kinetic extraction revealed that the bismuth ions were extracted at 100% 97%.

  18. Sedative, membrane stability, cytotoxic and antioxidant properties of methanol extract of leaves of Protium serratum Wall.

    Directory of Open Access Journals (Sweden)

    Md. Rafikul Islam

    2014-09-01

    Full Text Available Objective: To study the sedative, membrane stability, cytotoxic and antioxidant properties of the leaves of Protium serratum extracted using methanol. Methods: Sedative test was performed using hole cross and open field methods at 200 and 400 mg/kg. Membrane stability of red blood cell was used for anti-inflammatory test at different concentrations. Cytotoxic study was performed using brine shrimp lethality test. Total flavonoid contents, total phenol contents and reducing power were used to assess antioxidant properties of the extract. Results: Extract showed better sedative action at lower doses in both experiments. Maximum 73.33% locomotion reduction was found at 200 mg/kg at 1 20 min and that was 89.29% for diazepam in hole cross test. In membrane stability test, extract and standard drug diclofenac have 35.66% and 91.20% stability, respectively. LC50 value of the extract was 22.91 µg/mL. Total phenol and flavonoid contents were (55.53依14.63 mg gallic acid equivalent per gram of extract and (1 06.33依7.35 mg of quercetin equivalent per gram of extract, respectively per gram of extract. Significant reducing power was observed as compared to ascorbic acid. Conclusions: Extract possesses good pharmacological properties. Hence, further extensive study is essential to find out possible active constituents for the treatment of anxiety, inflammation or sickle cell disease, cancer and free radical mediated abnormalities.

  19. CRC 1114 - Report Membrane Deformation by N-BAR Proteins: Extraction of membrane geometry and protein diffusion characteristics from MD simulations

    OpenAIRE

    Peters, Jan Henning; Gräser, Carsten; Klein, Rupert

    2017-01-01

    We describe simulations of Proteins and artificial pseudo-molecules interacting and shaping lipid bilayer membranes. We extract protein diffusion Parameters, membrane deformation profiles and the elastic properties of the used membrane models in preparation of calculations based on a large scale continuum model.

  20. Hypochlorite- and hypobromite-mediated radical formation and its role in cell lysis

    DEFF Research Database (Denmark)

    Hawkins, C L; Brown, B E; Davies, Michael Jonathan

    2001-01-01

    trapping, and it is shown that reaction of both oxidants with each cell type generates cell-derived radicals. Red blood cells exposed to nonlytic doses of HOCl generate novel nitrogen-centered radicals whose formation is GSH dependent. In contrast, HOBr gives rise to nitrogen-centered, membrane....... In this study it is shown that HOBr induces red blood cell lysis at approximately 10-fold lower concentrations than HOCl, whereas with monocyte (THP1) and macrophage (J774) cells HOCl and HOBr induce lysis at similar concentrations. The role of radical formation during lysis has been investigated by EPR spin......-derived protein radicals. With lytic doses of either oxidant, protein (probably hemoglobin)-derived, nitrogen-centered radicals are observed. Unlike the red blood cells, treatment of monocytes and macrophages with HOCl gives significant radical formation only under conditions where cell lysis occurs concurrently...

  1. Membrane contactor assisted water extraction system for separating hydrogen peroxide from a working solution, and method thereof

    Science.gov (United States)

    Snyder, Seth W [Lincolnwood, IL; Lin, Yupo J [Naperville, IL; Hestekin', Jamie A [Fayetteville, AR; Henry, Michael P [Batavia, IL; Pujado, Peter [Kildeer, IL; Oroskar, Anil [Oak Brook, IL; Kulprathipanja, Santi [Inverness, IL; Randhava, Sarabjit [Evanston, IL

    2010-09-21

    The present invention relates to a membrane contactor assisted extraction system and method for extracting a single phase species from multi-phase working solutions. More specifically one preferred embodiment of the invention relates to a method and system for membrane contactor assisted water (MCAWE) extraction of hydrogen peroxide (H.sub.2O.sub.2) from a working solution.

  2. Liquid membrane extraction techniques for trace metal analysis and speciation in environmental and biological matrices

    Energy Technology Data Exchange (ETDEWEB)

    Ndungu, Kuria

    1999-04-01

    In this thesis, liquid-membrane-based methods for the analysis of trace metal species in samples of environmental and biological origin were developed. By incorporating extracting reagents in the membrane liquid, trace metal ions were selectively separated from humic-rich natural waters and urine samples, prior to their determination using various instrumental techniques. The extractions were performed in closed flow systems thus allowing easy automation of both the sample clean-up and enrichment. An acidic organophosphorus reagent (DEHPA) and a basic tetraalkylammonium reagent (Aliquat-336) were used as extractants in the membrane liquid to selectively extract and enrich cationic and anionic metal species respectively. A speciation method for chromium species was developed that allowed the determination of cationic Cr(III) species and anionic CR(VI) species in natural water samples without the need of a chromatographic separation step prior to their detection. SLM was also coupled on-line to potentiometric stripping analysis providing a fast and sensitive method for analysis of Pb in urine samples. A microporous membrane liquid-liquid extraction (MMLLE) method was developed for the determination of organotin compounds in natural waters that reduced the number of manual steps involved in the LLE of organotin compounds prior to their CC separation. Clean extracts obtained after running unfiltered humic-rich river water samples through the MMLLE flow system allowed selective determination of all the organotin compounds in a single run using GC-MS in the selected ion monitoring mode (SIM) 171 refs, 9 figs, 4 tabs

  3. Sampling and monitoring of biogenic emissions by eucalyptus leaves using membrane extraction with sorbent interface (MESI).

    Science.gov (United States)

    Wang, Limei; Lord, Heather; Morehead, Rick; Dorman, Frank; Pawliszyn, Janusz

    2002-10-23

    Membrane extraction with sorbent interface (MESI) has been applied to monitor plant fragrance volatiles emitted into indoor air. The main components of the MESI system are a membrane module and a trap, which can be connected directly to a GC or GC-MS for simultaneous multicomponent extraction and monitoring. A polydimethylsiloxane (PDMS) membrane and two different traps, PDMS and Tenax, as well as a DC current supply for trap desorption have been applied in this research. After the membrane module is placed in contact with the plant, the MESI/GC-MS provides semicontinuous characterization of volatile compounds emitted. The MESI device has been applied to monitor the biogenic volatile organic compounds released during the first 8 h after a branch was cut from a Eucalyptus dunnii tree. The study demonstrates that the MESI system is a simple and useful tool for monitoring changes in emission processes as a function of time.

  4. Thin extractive membrane for monitoring actinides in aqueous streams.

    Science.gov (United States)

    Chavan, Vivek; Paul, Sumana; Pandey, Ashok K; Kalsi, P C; Goswami, A

    2013-09-15

    Alpha spectrometry and solid state nuclear track detectors (SSNTDs) are used for monitoring ultra-trace amount of alpha emitting actinides in different aqueous streams. However, these techniques have limitations i.e. alpha spectrometry requires a preconcentration step and SSNTDs are not chemically selective. Therefore, a thin polymer inclusion membrane (PIM) supported on silanized glass was developed for preconcentraion and determination of ultra-trace concentration of actinides by α-spectrometry and SSNTDs. PIMs were formed by spin coating on hydrophobic glass slide or solvent casting to form thin and self-supported membranes, respectively. Sorption experiments indicated that uptakes of actinides in the PIM were highly dependent on acidity of solution i.e. Am(III) sorbed up to 0.1 molL(-1) HNO₃, U(VI) up to 0.5 molL(-1) HNO₃ and Pu(IV) from HNO₃ concentration as high as 4 molL(-1). A scheme was developed for selective sorption of target actinide in the PIM by adjusting acidity and oxidation state of actinide. The actinides sorbed in PIMs were quantified by alpha spectrometry and SSNTDs. For SSNTDs, neutron induced fission-fragment tracks and α-particle tracks were registered in Garware polyester and CR-39 for quantifications of natural uranium and α-emitting actinides ((241)Am/(239)Pu/(233)U), respectively. Finally, the membranes were tested to quantify Pu in 4 molL(-1) HNO3 solutions and synthetic urine samples. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Enhanced detergent extraction for analysis of membrane proteomes by two-dimensional gel electrophoresis

    Directory of Open Access Journals (Sweden)

    Hsu Kimberly K

    2005-06-01

    Full Text Available Abstract Background The analysis of hydrophobic membrane proteins by two-dimensional gel electrophoresis has long been hampered by the concept of inherent difficulty due to solubility issues. We have optimized extraction protocols by varying the detergent composition of the solubilization buffer with a variety of commercially available non-ionic and zwitterionic detergents and detergent-like phospholipids. Results After initial analyses by one-dimensional SDS-PAGE, quantitative two-dimensional analyses of human erythrocyte membranes, mouse liver membranes, and mouse brain membranes, extracted with buffers that included the zwitterionic detergent MEGA 10 (decanoyl-N-methylglucamide and the zwitterionic lipid LPC (1-lauroyl lysophosphatidylcholine, showed selective improvement over extraction with the common 2-DE detergent CHAPS (3 [(3-cholamidopropyldimethylammonio]-1-propanesulfonate. Mixtures of the three detergents showed additive improvements in spot number, density, and resolution. Substantial improvements in the analysis of a brain membrane proteome were observed. Conclusion This study demonstrates that an optimized detergent mix, coupled with rigorous sample handling and electrophoretic protocols, enables simple and effective analysis of membrane proteomes using two-dimensional electrophoresis.

  6. Concentration of antioxidant polyphenols from Thymus capitatus extracts by membrane process technology.

    Science.gov (United States)

    Achour, Sami; Khelifi, Eltaief; Attia, Yesmine; Ferjani, Ezzeddine; Noureddine Hellal, Ahmed

    2012-06-01

    Thymus capitatus is a Mediterranean plant characterized by its antioxidant polyphenols of which the most known are the carnosic and rosmarinic acids. In this way, this study aims to concentrate these acids by membrane processes. The thyme essential oil composition was established by capillary GC-MS and 27 components were identified representing 98.93%± 1.97% of total oils. The antioxidant test for permeate and retentate of methanolic and aqueous extract were determined using 3 types of membranes. The results showed that the synthetic NF membrane is able to trap and concentrate phenolic compounds in the retentate much better than the NF commercial and UF synthetic membrane. The results of the total phenolic content (TPC) showed a significant value of the polyphenol content present in the aqueous extract with 175.53 mg Gallic Acid Equivalents (GAE)/g of extract. The spectrum of the aqueous extract of Thymus capitatus showed the presence of 3 visible peaks, the 1st one at 217 nm corresponding to the carnosic acid, the 2nd one at 277 nm for essential oils, and the last one at 326 nm attributed to the rosmarinic acid. The commercial membrane NF-DK succeeded to concentrate rosmarinic acid and can be considered as a stage towards the concentration of this product with a high added value. © 2012 Institute of Food Technologists®

  7. Grape extract protects against γ-radiation-induced membrane damage strains of human erythrocytes

    International Nuclear Information System (INIS)

    Das, Subir Kumar

    2017-01-01

    The membrane integrity of circulating red blood cells (RBCs) is compromised by the deleterious actions of γ-radiation in humans. Grapes are the richest source of antioxidants due to presence of potentially bioactive phytochemicals. The objective of the present study was to assess the radioprotective actions of grape extracts against the γ-radiation-induced membrane permeability of human erythrocytes. The scavenging activities in seeds of grape in DPPH, hydrogen peroxide and hydroxyl radicals, were higher than skin or pulp of different cultivars. Grape extracts also showed appreciable extent of total antioxidant capacity and effective antihemolytic action. Grape extracts significantly ameliorated the γ-radiation-induced increase of the levels of thiobarbituric acid-reactive substances (TBARS, an index of lipid peroxidation) in the RBC membrane ghosts. Stored blood showed higher levels of K + ion as compared to the normal blood which was elevated by γ-radiation. Membrane ATPase was inhibited by the exposure to γ-radiation.Treatment of RBCs with the grape extracts prior to the exposure of γ-radiation significantly mitigated these changes in the erythrocyte membranes caused by the lower dose of radiation (4 Gy). (author)

  8. Fatty acids are rapidly delivered to and extracted from membranes by methyl-beta-cyclodextrin.

    Science.gov (United States)

    Brunaldi, Kellen; Huang, Nasi; Hamilton, James A

    2010-01-01

    We performed detailed biophysical studies of transfer of long-chain fatty acids (FAs) from methyl-beta-CD (MBCD) to model membranes (egg-PC vesicles) and cells and the extraction of FA from membranes by MBCD. We used i) fluorescein phosphatidylethanolamine to detect transfer of FA anions arriving in the outer membrane leaflet; ii) entrapped pH dyes to measure pH changes after FA diffusion (flip-flop) across the lipid bilayer; and iii) soluble fluorescent-labeled FA binding protein to measure the concentration of unbound FA in water. FA dissociated from MBCD, bound to the membrane, and underwent flip-flop within milliseconds. In the presence of vesicles, MBCD maintained the aqueous concentration of unbound FA at low levels comparable to those measured with albumin. In studies with cells, addition of oleic acid (OA) complexed with MBCD yielded rapid (seconds) dose-dependent OA transport into 3T3-L1 preadipocytes and HepG2 cells. MBCD extracted OA from cells and model membranes rapidly at concentrations exceeding those required for OA delivery but much lower than concentrations commonly used for extracting cholesterol. Compared with albumin, MBCD can transfer its entire FA load and is less likely to extract cell nutrients and to introduce impurities.

  9. Final Report - Energy Reduction and Advanced Water Removal via Membrane Solvent Extraction Technology

    Energy Technology Data Exchange (ETDEWEB)

    Reed, John; Fanselow, Dan; Abbas, Charles; Sammons, Rhea; Kinchin, Christopher

    2014-08-06

    3M and Archer Daniels Midland (ADM) collaborated with the U.S. Department of Energy (DOE) to develop and demonstrate a novel membrane solvent extraction (MSE) process that can substantially reduce energy and water consumption in ethanol production, and accelerate the fermentation process. A cross-flow membrane module was developed, using porous membrane manufactured by 3M. A pilot process was developed that integrates fermentation, MSE and vacuum distillation. Extended experiments of 48-72 hours each were conducted to develop the process, verify its performance and begin establishing commercial viability.

  10. Fatty acids are rapidly delivered to and extracted from membranes by methyl-β-cyclodextrin

    OpenAIRE

    Brunaldi, Kellen; Huang, Nasi; Hamilton, James A.

    2010-01-01

    We performed detailed biophysical studies of transfer of long-chain fatty acids (FAs) from methyl-β-CD (MBCD) to model membranes (egg-PC vesicles) and cells and the extraction of FA from membranes by MBCD. We used i) fluorescein phosphatidylethanolamine to detect transfer of FA anions arriving in the outer membrane leaflet; ii) entrapped pH dyes to measure pH changes after FA diffusion (flip-flop) across the lipid bilayer; and iii) soluble fluorescent-labeled FA binding protein to measure the...

  11. Study of supercritical CO2 extraction and nanofiltration membrane separation coupling

    International Nuclear Information System (INIS)

    Sarrade, S.

    1994-12-01

    The aim of this thesis is to study the coupling of two extraction techniques, nanofiltering and supercritical fluids, designing and building an experimental device that enables both supercritical CO 2 extraction and nanofiltering membrane separation. The purpose is to reach high splitting up levels on small molecule mixtures. The document is divided in four parts : a bibliographic study on these two techniques; a description of the membranes and the products, as well as the experimental device; the characterization and modelization of transfer mechanism in aqueous solutions; a presentation of the results obtained by coupling the two techniques. (TEC). 45 tabs., 70 figs., 98 refs

  12. Parallel artificial liquid membrane extraction as an efficient tool for removal of phospholipids from human plasma

    DEFF Research Database (Denmark)

    Ask, Kristine Skoglund; Bardakci, Turgay; Parmer, Marthe Petrine

    2016-01-01

    Generic Parallel Artificial Liquid Membrane Extraction (PALME) methods for non-polar basic and non-polar acidic drugs from human plasma were investigated with respect to phospholipid removal. In both cases, extractions in 96-well format were performed from plasma (125μL), through 4μL organic...... solvent used as supported liquid membranes (SLMs), and into 50μL aqueous acceptor solutions. The acceptor solutions were subsequently analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using in-source fragmentation and monitoring the m/z 184→184 transition for investigation...

  13. EXTRACTION DU Cr(VI PAR MEMBRANE POLYMERE A INCLUSION

    Directory of Open Access Journals (Sweden)

    O KEBICHE SENHADJI

    2008-06-01

    Le pH de la solution aqueuse constituant la phase source est un paramètre clé dans l’opération de transport du Cr(VI à travers les MPIs étudiées. Un pH de 1,2 est recommandé pour la réalisation de l’extraction dans les conditions optimales déterminées.

  14. Alveolar Ridge Preservation Using Allografts and Dense Polytetrafluoroethylene Membranes With Open Membrane Technique in Unhealthy Extraction Socket.

    Science.gov (United States)

    Cheon, Gi-Beom; Kang, Kyung Lhi; Yoo, Mi-Kyung; Yu, Jeoung-A; Lee, Dong-Woon

    2017-08-01

    We evaluated the effectiveness of the open membrane technique using a high-density polytetrafluoroethylene (dPTFE) membrane with freeze-dried bone allografts in damaged sockets for alveolar ridge preservation (ARP). This retrospective study included 26 sites from 20 patients who had received ARP for the placement of dental implants. ARP was conducted using dPTFE membrane with allografts on the day of extraction without primary closure. When the membrane was removed after 4 weeks, the newly formed reddish tissue at the grafted site was checked (first outcome, clinical evaluation). Four months after membrane removal, a core biopsy was performed from the center of the grafted site before implant placement (second outcome, histomorphometric evaluation). Radiographic measurements of alveolar bone changes between implant prosthesis delivery and the 1-year follow-up were obtained (third outcome, radiographic evaluation). A total of 23 sites from 18 patients had no complications during the follow-up period. Three sites from two patients were excluded because of early membrane removal. Newly formed reddish tissue was found at 15 sites, and partially formed tissue was found at 8 sites. Although we were unable to harvest bone core from all sites, histomorphometric analysis in 11 patients indicated that the mean area of new bone was 28.48% ± 6.60%, that of the remaining graft particle was 27.68% ± 9.18%, and that of fibrous tissue was 43.84% ± 6.98%. The mean loss of marginal bone was 0.13 ± 0.06 mm at the mesial area and 0.15 ± 0.06 mm at the distal area, as assessed using radiographic evaluations. The results of this nonrandomized study suggest that this technique may be an appropriate procedure for ARP. Further studies with a control group and more subjectives can be designed based on this study.

  15. Nonequilibrium Phase Transitions in the Extraction of Membrane Tubes by Molecular Motors

    Science.gov (United States)

    Tailleur, J.; Evans, M. R.; Kafri, Y.

    2009-03-01

    The extraction of membrane tubes by molecular motors is known to play an important role for the transport properties of eukaryotic cells. By studying a generic class of models for the tube extraction, we discover a rich phase diagram. In particular we show that the density of motors along the tube can exhibit shocks, inverse shocks, and plateaux, depending on parameters which could in principle be probed experimentally. In addition the phase diagram exhibits interesting reentrant behavior.

  16. Micro-electromembrane extraction across free liquid membranes. Instrumentation and basic principles

    OpenAIRE

    Kubáň, P. (Pavel); Boček, P. (Petr)

    2014-01-01

    Fundamental principles and instrumental set-up of a novel concept of electromembrane extraction downscaled to a micro-format is presented. In this set-up, free liquid membranes are applied, which are not anchored in any supporting material and their dimensions can be precisely defined. The extraction system is examined with a set of two, which enable real-time visualizations using a USB microscope camera.

  17. Study of aqueous extract of three medicinal plants on cell membrane ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate the effect of aqueous extract of three medicinal plants, Artemisia dracunculus L, Cuminum cyminum L and Heracleum persicum Desf, which contain saponins on biological membrane. Also in this study, some of their physicochemical properties were studied. At the first step, the aqueous ...

  18. Micro-electromembrane extraction across free liquid membranes. Instrumentation and basic principles

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 1346, Jun (2014), s. 25-33 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : free liquid membranes * micro-electromembrane extraction * sample pretreatment Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.169, year: 2014

  19. [Effect of extracted ZG from gardenia on Hep-2 cell membrane post infected with parainfluenza virus type 1 (PIV-1)].

    Science.gov (United States)

    Guo, Shan-Shan; Huang, Yang; Zhao, Ye; Gao, Ying-Jie; Gong, Wen-Feng; Cui, Xiao-Lan

    2007-09-01

    In order to study the anti-viral mechanism of extracted ZG from Gardenia, the effect of extracted ZG on Hep-2 cell membrane potential, Na -K+-ATPase activity and membrane fluidity post infected with parainfluenza virus type 1 (PIV-1) was observed. Acetylcholine which was fluorescent labeled with DiBAC4 (3) was taken as positive control to observe the changes of membrane potential and was measured by flow cytometer. The phosphorus determination method and spectrophotometer were used to measure the Na+-K+-ATPase activity of Hep-2 cell membrane post PIV-1 infection. Hep-2 cell membrane phospholipids was labeled with fluorescent NBD-C6-HPC and membrane fluidity was measured by confocal laser scanning microscope. The results demonstated that after PIV-1 infection the Hep-2 cell membrane potential decreased significantly and the membrane was in the state of hyperpolarization, Na+-K+-ATPase activity increased and membrane fluidity decreased significantly. There was no apparent interferring effect of extracted ZG on the changes of membrane potential and Na+-K+-ATPase activity post PIV-1 infection, while membrane fluidity was improved significantly. Acetylcholine improved the state of hyperpolarization. The changes of membrane potential, Na -K+-ATPase activity and membrane fluidity might be the biomechanism of PIV-1 infectoin. The extracted ZG improved membrane fluidity to prevent from PIV-1 infection by protecting the cell membrane, which was probably the mechanism of anti-PIV-1 activity of the extracted ZG, but ZG probably had nothing to do with membrane potential and Na+-K+-ATPase activity.

  20. The Ms6 Mycolyl-Arabinogalactan Esterase LysB is Essential for an Efficient Mycobacteriophage-Induced Lysis

    Directory of Open Access Journals (Sweden)

    Adriano M. Gigante

    2017-11-01

    Full Text Available All dsDNA phages encode two proteins involved in host lysis, an endolysin and a holin that target the peptidoglycan and cytoplasmic membrane, respectively. Bacteriophages that infect Gram-negative bacteria encode additional proteins, the spanins, involved in disruption of the outer membrane. Recently, a gene located in the lytic cassette was identified in the genomes of mycobacteriophages, which encodes a protein (LysB with mycolyl-arabinogalactan esterase activity. Taking in consideration the complex mycobacterial cell envelope that mycobacteriophages encounter during their life cycle, it is valuable to evaluate the role of these proteins in lysis. In the present work, we constructed an Ms6 mutant defective on lysB and showed that Ms6 LysB has an important role in lysis. In the absence of LysB, lysis still occurs but the newly synthesized phage particles are deficiently released to the environment. Using cryo-electron microscopy and tomography to register the changes in the lysis phenotype, we show that at 150 min post-adsorption, mycobacteria cells are incompletely lysed and phage particles are retained inside the cell, while cells infected with Ms6wt are completely lysed. Our results confirm that Ms6 LysB is necessary for an efficient lysis of Mycobacterium smegmatis, acting, similarly to spanins, in the third step of the lysis process.

  1. Numerical simulation of reactive extraction of benzoic acid from wastewater via membrane contactors.

    Science.gov (United States)

    Ghadiri, Mehdi; Shirazian, Saeed

    2017-04-01

    Membrane-based non-dispersive solvent extraction is used in many chemical processes due to its significant benefits such as straightforward scale-up and low energy consumption. A mechanistic model was developed to predict recovery of benzoic acid (BA) from wastewater using membrane contactors. Model equations were derived for benzoic acid transport in the membrane module, and solved using FEM. The model findings were compared with experimental results, and an average deviation of 4% was observed between experimental and simulation results. Simulations showed that change in organic phase flowrate and initial concentration of BA does not have considerable effect on the removal efficiency of benzoic acid. In addition, increasing feed flowrate leads to the enhancement of convective mass transfer flux in the tube side of membrane contactor which decreases removal efficiency of benzoic acid.

  2. Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

    Directory of Open Access Journals (Sweden)

    Siekierka Anna

    2017-01-01

    Full Text Available Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity and energy requirements in charge/discharge steps. We described a configuration with anion-exchange membrane characterized by adsorption capacity of 35 mg/g of Li+ with 0.08Wh/g and removal efficiency of 60 % of lithium ions, using novel selective desalination technique.

  3. Hybrid capacitive deionization with anion-exchange membranes for lithium extraction

    Science.gov (United States)

    Siekierka, Anna; Bryjak, Marek

    2017-11-01

    Lithium is considered to be a critical material for various industrial fields. We present our studies on extraction lithium from diluted aqueous solution by novel hybrid system based on a membrane capacitive deionization and batteries desalination. Hybrid CDI is comprised by a lithium selective adsorbent, activated carbon electrode and anion-exchange membranes. Here, we demonstrated implication of various type of anion-exchange membranes and influence their properties on effective capacity and energy requirements in charge/discharge steps. We described a configuration with anion-exchange membrane characterized by adsorption capacity of 35 mg/g of Li+ with 0.08Wh/g and removal efficiency of 60 % of lithium ions, using novel selective desalination technique.

  4. Solvent extraction, membranes, and ion exchange in hydrometallurgical dilute metals separation

    International Nuclear Information System (INIS)

    Tavlarides, L.L.; Bae, J.H.; Lee, C.K.

    1987-01-01

    The separation methods which are used in the hydro-metallurgical field are reviewed and compared. Some processes in solvent extraction in use for recovery of crucial metals which are important to the US defense and economy are presented. Various commercial extractants are reviewed and categorized. Other methods such as liquid membranes and ions exchange resins used for dilute metal ions separation are summarized. These methods are compared with solvent extraction. Problems to overcome in the future development of these separation methods are also identified and discussed in this paper

  5. A mechanism of acquired resistance to complement-mediated lysis by Entamoeba histolytica.

    Science.gov (United States)

    Gutiérrez-Kobeh, L; Cabrera, N; Pérez-Montfort, R

    1997-04-01

    Some Entamoeba histolytica strains resist complement-mediated lysis by serum. Susceptible and resistant strains activate the complement system equivalently, but resistant amebas evade killing by membrane attack complexes. Our objective was to determine the mechanism by which trophozoites of E. histolytica resist lysis by human serum. Amebas were made resistant to lysis by incubation with increasing concentrations of normal human serum. The possibility that resistant cells ingest membrane attack complexes was explored by subcellular fractionation of susceptible and resistant trophozoites treated with sublytic concentrations of human serum containing radiolabeled C9. In both cases, most of the label was in the fractions containing plasma membrane. The susceptible strain consistently showed more label associated with these fractions than the resistant strain. Thus, the possibility that the membrane attack complexes were released to the medium was explored. Both resistant and susceptible trophozoites release to the medium similar amounts of material excluded by Sepharose CL-2B in the presence or absence of normal human serum. Labeled C9 elutes together with the main bulk of proteins from the medium: this indicates that it is not in vesicles or high molecular weight aggregates. Coincubation of susceptible amebas with lysates of resistant trophozoites confers resistance to susceptible cells within 30 min. Resistance to lysis by serum can also be acquired by susceptible amebas after coincubation with lysates from human erythrocytes or after feeding them with whole human red blood cells. Resistant but not susceptible trophozoites show intense immunofluorescent staining on their surface with anti-human erythrocytic membrane antibody. These results suggest that amebas acquire resistance to lysis by serum by incorporating into their membranes complement regulatory proteins.

  6. Integration of ceramic membrane and compressed air-assisted solvent extraction (CASX) for metal recovery.

    Science.gov (United States)

    Li, Chi-Wang; Chiu, Chun-Hao; Lee, Yu-Cheng; Chang, Chia-Hao; Lee, Yu-Hsun; Chen, Yi-Ming

    2010-01-01

    In our previous publications, compressed air-assisted solvent extraction process (CASX) was developed and proved to be kinetically efficient process for metal removal. In the current study, CASX with a ceramic MF membrane integrated for separation of spent solvent was employed to remove and recover metal from wastewater. MF was operated either in crossflow mode or dead-end with intermittent flushing mode. Under crossflow mode, three distinct stages of flux vs. TMP (trans-membrane pressure) relationship were observed. In the first stage, flux increases with increasing TMP which is followed by the stage of stable flux with increasing TMP. After reaching a threshold TMP which is dependent of crossflow velocity, flux increases again with increasing TMP. At the last stage, solvent was pushed through membrane pores as indicated by increasing permeate COD. In dead-end with intermittent flushing mode, an intermittent flushing flow (2 min after a 10-min or a 30-min dead-end filtration) was incorporated to reduce membrane fouling by flush out MSAB accumulated on membrane surface. Effects of solvent concentration and composition were also investigated. Solvent concentrations ranging from 0.1 to 1% (w/w) have no adverse effect in terms of membrane fouling. However, solvent composition, i.e. D(2)EHPA/kerosene ratio, shows impact on membrane fouling. The type of metal extractants employed in CASX has significant impact on both membrane fouling and the quality of filtrate due to the differences in their viscosity and water solubility. Separation of MSAB was the limiting process controlling metal removal efficiency, and the removal efficiency of Cd(II) and Cr(VI) followed the same trend as that for COD.

  7. Erythrocyte lysis in isotonic solution of ammonium chloride: Theoretical modelling and experimental verification

    NARCIS (Netherlands)

    Chernyshev, A.V.; Tarasov, P.A.; Semianov, K.A.; Nekrasov, V.M.; Hoekstra, A.G.; Maltsev, V.P.

    2008-01-01

    A mathematical model of erythrocyte lysis in isotonic solution of ammonium chloride is presented in frames of a statistical approach. The model is used to evaluate several parameters of mature erythrocytes (volume, surface area, hemoglobin concentration, number of anionic exchangers on membrane,

  8. Comparison of membrane assisted solvent extraction, stir bar sorptive extraction, and solid phase microextraction in analysis of tetramine in food.

    Science.gov (United States)

    De Jager, Lowri S; Perfetti, Gracia A; Diachenko, Gregory W

    2009-04-01

    Three environmentally friendly extraction techniques, membrane assisted solvent extraction (MASE), stir bar sorptive extraction (SBSE), and headspace solid phase microextraction (HS-SPME), were compared for the direct analysis of the highly toxic rodenticide tetramine in food. The optimized MASE method was applied to seven foods fortified with tetramine and compared to previously reported SBSE and HS-SPME results. Parameters such as the standard addition linearity (MASE (0.964-0.999), SBSE (0.966-0.999), HS-SPME (0.955-0.999)), recovery (MASE (12-86%), SBSE (36-130%), HS-SPME (50-200%)), reproducibility (MASE (3.0-30%), SBSE (4.4-9.6%), HS-SPME (1-12%)), and LOD (MASE (1.6-6.4 ng/g), SBSE (0.2-2.1 ng/g), HS-SPME (0.9-4.3 ng/g)) were compared.

  9. Defective lysis of streptomycin-resistant escherichia coli cells infected with bacteriophage f2.

    Science.gov (United States)

    De Mars Cody, J; Conway, T W

    1981-01-01

    A lysis defect was found to account for the failure of a streptomycin-resistant strain of Escherichia coli to form plaques when infected with the male-specific bacteriophage f2. The lysis defect was associated with the mutation to streptomycin resistance. Large amounts of apparently normal bacteriophage accumulated in these cells. Cell-free extracts from both the parental and mutant strains synthesized a potential lysis protein in considerable amounts in response to formaldehyde-treated f2 RNA but not in response to untreated RNA. As predicted from the nucleotide sequence of the analogous MS2 phage, the protein synthesized in vitro had the expected molecular weight and lacked glycine. The cistron for the lysis protein overlapped portions of the coat and replicase cistrons and was translated in the +1 reading frame. Initiation at the lysis protein cistron may be favored by translation errors that expose the normally masked initiation site, and streptomycin-resistant ribosomes, known to have more faithful translation properties, may be unable to efficiently synthesize the lysis protein. Images PMID:6783768

  10. chemical studies on the extraction of certain metal ions from aqueous solution by liquid emulsion membrane

    International Nuclear Information System (INIS)

    Kassem, A.T.

    2011-01-01

    In this thesis four systems are addressed related to the use of liquid emulsion membranes (ELM) based on Co(III)dicarbiolide and. The system was dedicated for permeation of cadmium , cobalt Nickel and lead for use of this system for preconcentration and separation of cadmium, cobalt, nickel and lead. The work carried out in this thesis is presented in three parts, namely; introduction, experimental and results and discussion.The first chapter is the introduction which includes aim of work, basic concepts of liquid membranes; liquid emulsion membranes; different models of emulsion permeation, literature survey of extraction chemistry of cadmium, cobalt, nickel and lead. Chapter two includes the experimental part. In this part detailed outlines on the chemicals and different elements used were given. Different instruments as well as analytical techniques were outlines. The preparation of liquid emulsion membrane and the permeation techniques were presented in details. The third chapter deals with the results and discussion. This chapter is divided into four main parts, the four parts is concerned with cadmium/Co(III) dicarbolide/NTA, EDTA, DPTA and DCTA systems. In this part the permeation of Cd(II) aqueous solution by the membrane used was experimented based on liquid-liquid extraction studies of cadmium from different sodium chloride molarities (from 0.01 to 0.1 M) by 0.01 M Cobalt(III) dicarbolides. It was found that the extraction of with cadmium is higher following in the first system, the permeation of the toxic elements, Cd(II) from HCl/sodium chloride medium was carried out using liquid emulsion membrane containing Co(III)dicarbiolide in xylene as carrier, Spain 80/ Spain 85(1:3) as surfactant and NTA, EDTA, DPTA and DCTA as a stripping solutions.

  11. Electromembrane extraction of tartrazine from food samples: Effects of nano-sorbents on membrane performance.

    Science.gov (United States)

    Yaripour, Saeid; Mohammadi, Ali; Nojavan, Saeed

    2016-07-01

    In the present study, for the first time electromembrane extraction followed by high-performance liquid chromatography coupled with ultraviolet detection was developed and validated for the determination of tartrazine in some food samples. The parameters influencing electromembrane extraction were evaluated and optimized. The membrane consists of 1-octanol immobilized in the pores of a hollow fiber. As a driving force, a 30 V electrical field was applied to make the analyte migrate from sample solution with pH 3, through the supported liquid membrane into an acceptor solution with pH 10. Best preconcentration (enrichment factor >21) was obtained in extraction duration of 15 min. Effects of some solid nano-sorbents like carbon nanotubes and molecularly imprinted polymers on membrane performance and electromembrane extraction efficiency were evaluated. The method provided the linearity in the range 25-1000 ng/mL for tartrazine (R(2) > 0.9996) with repeatability range (RSD) between 3.8 and 8.5% (n = 3). The limits of detection and quantitation were 7.5 and 25 ng/mL, respectively. Finally, the method was applied to the determination and quantification of tartrazine from some food samples with relative recoveries in the range between 90 and 98%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Microphotographs of cyanobacteria documenting the effects of various cell-lysis techniques

    Science.gov (United States)

    Rosen, Barry H.; Loftin, Keith A.; Smith, Christopher E.; Lane, Rachael F.; Keydel, Susan P.

    2011-01-01

    Cyanotoxins are a group of organic compounds biosynthesized intracellularly by many species of cyanobacteria found in surface water. The United States Environmental Protection Agency has listed cyanotoxins on the Safe Drinking Water Act's Contaminant Candidate List 3 for consideration for future regulation to protect public health. Cyanotoxins also pose a risk to humans and other organisms in a variety of other exposure scenarios. Accurate and precise analytical measurements of cyanotoxins are critical to the evaluation of concentrations in surface water to address the human health and ecosystem effects. A common approach to total cyanotoxin measurement involves cell membrane disruption to release the cyanotoxins to the dissolved phase followed by filtration to remove cellular debris. Several methods have been used historically, however no standard protocols exist to ensure this process is consistent between laboratories before the dissolved phase is measured by an analytical technique for cyanotoxin identification and quantitation. No systematic evaluation has been conducted comparing the multiple laboratory sample processing techniques for physical disruption of cell membrane or cyanotoxins recovery. Surface water samples collected from lakes, reservoirs, and rivers containing mixed assemblages of organisms dominated by cyanobacteria, as well as laboratory cultures of species-specific cyanobacteria, were used as part of this study evaluating multiple laboratory cell-lysis techniques in partnership with the U.S. Environmental Protection Agency. Evaluated extraction techniques included boiling, autoclaving, sonication, chemical treatment, and freeze-thaw. Both treated and untreated samples were evaluated for cell membrane integrity microscopically via light, epifluorescence, and epifluorescence in the presence of a DNA stain. The DNA stain, which does not permeate live cells with intact membrane structures, was used as an indicator for cyanotoxin release into the

  13. Orthodontic space closure in combination with membrane supported healing of extraction sockets (MHE) a pilot study.

    Science.gov (United States)

    Tiefengraber, Julia; Diedrich, Peter; Fritz, Ulrike; Lantos, Peter

    2002-09-01

    In periodontology and implantology the guided bone regeneration (GBR) technique represents a well established and successful method for augmentation of alveolar bone. The aim of the present study was to evaluate what advantages, if any, are offered for orthodontic space closure by membrane supported healing of extraction sockets (MHE) (criteria: rate of movement, incidence of gingival clefts, atrophy of the alveolar bone). Within the scope of orthodontic therapy with a complete fixed appliance, three girls aged 11-14 years with indication for extraction of the first premolars were unilaterally augmented with an e-PTFE membrane (Gore-Tex((R)), W. L. Gore & Associates, Flagstaff, AZ, USA) immediately after premolar extraction. The study was performed in the split-mouth technique. An atraumatic extraction without digital compression was performed on the control side. The membranes were fixed with a Frios((R)) fixation set (Friadent, GmbH, Mannheim, Germany) and removed after 6 to 8 weeks. 1 week after membrane removal, space closure was started simultaneously with passive rectangular segmented archwires using Sentalloy((R)) closed coil springs (GAC International, Inc., Gräfelfing, Germany) at a constant force of 200 cN. The transversal and vertical dimensions of the alveolar bone the rate of space closure were determined clinically and radiographically. Complications were not observed in any patient. The MHE-treated alveolar region showed pronounced stability of the transversal dimension. Space closure was performed in all cases without gingival clefts being induced. The control side showed distinct atrophy as well as gingival clefts. No differences were recorded in the rate of space closure. The MHE technique seems to be a suitable means of creating favorable periodontal conditions for tooth movement, especially in cases of alveolar bone loss after extraction or trauma.

  14. The liquid membrane for extraction of Yttrium and Dysprosium from Acid Nitric

    International Nuclear Information System (INIS)

    Johny, W.S.; Raldi-Artono-Koestoer; Kris-Tri-Basuki; Sudibyo

    1996-01-01

    The determination of surfactant in liquid membrane has been done. The surfactant is span-80 (sorbitol-monooleate), the liquid membrane phase was the organic phase (O), the internal liquid phase (W) with ratio O/W = 1, and surfactant. The organic phase using D 2 EHPA in the kerosene and the internal liquid phase using aqua des or acid nitric. The determination of surfactant with variation of span-80 (0,25 - 2%) in the liquid membrane volume. The speed of stirrer was 3500 rpm in 20 minute. The ratio of liquid membrane phase form and external phase (aqua des or acid nitric) was 1, the speed of stirrer was 350 rpm in 10 minute (permeation process). The liquid phase and the liquid membrane phase was separated and then determinated the volume of liquid membrane, the result of percentage of span-80 was 0,25 % volume. The extraction of yttrium and dysprosium in 2 M HNO 3 was Kd y = 2.945 and Kd D y = 0.019

  15. Solvent-extraction and Langmuir-adsorption-based transport in chemically functionalized nanopore membranes.

    Science.gov (United States)

    Odom, Damian J; Baker, Lane A; Martin, Charles R

    2005-11-10

    We have investigated the transport properties of nanopore alumina membranes that were rendered hydrophobic by functionalization with octadecyltrimethoxysilane (ODS). The pores in these ODS-modified membranes are so hydrophobic that they are not wetted by water. Nevertheless, nonionic molecules can be transported from an aqueous feed solution on one side of the membrane, through the dry nanopores, and into an aqueous receiver solution on the other side. The transport mechanism involves Langmuir-type adsorption of the permeating molecule onto the ODS layers lining the pore walls, followed by solid-state diffusion along these ODS layers; we have measured the diffusion coefficients associated with this transport process. We have also investigated the transport properties of membranes prepared by filling the ODS-modified pores with the water-immiscible (hydrophobic) liquid mineral oil. In this case the transport mechanism involves solvent extraction of the permeating molecule into the mineral oil subphase confined with the pores, followed by solution-based diffusion through this liquid subphase. Because of this different transport mechanism, the supported-liquid membranes show substantially better transport selectivity than the ODS-modified membranes that contain no liquid subphase.

  16. Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

    International Nuclear Information System (INIS)

    Rogers, J.D.

    1994-01-01

    This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport

  17. Mathematical modeling of liquid/liquid hollow fiber membrane contactor accounting for interfacial transport phenomena: Extraction of lanthanides as a surrogate for actinides

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.D.

    1994-08-04

    This report is divided into two parts. The second part is divided into the following sections: experimental protocol; modeling the hollow fiber extractor using film theory; Graetz model of the hollow fiber membrane process; fundamental diffusive-kinetic model; and diffusive liquid membrane device-a rigorous model. The first part is divided into: membrane and membrane process-a concept; metal extraction; kinetics of metal extraction; modeling the membrane contactor; and interfacial phenomenon-boundary conditions-applied to membrane transport.

  18. Extraction of Penicillin V from Simulated Fermentation Broth by Liquid-Liquid Membrane Technique

    OpenAIRE

    Khalid W. Hameed

    2012-01-01

    Liquid-liquid membrane extraction technique, pertraction, using three types of solvents (methyl isobutyl ketone, n-butyl acetate, and n-amyl acetate) was used for recovery of penicillin V from simulated fermentation broth under various operating conditions of pH value (4-6) for feed and (6-8) for receiver phase, time (0-40 min), and agitation speed (300-500 rpm) in a batch laboratory unit system. The optimum conditions for extraction were at pH of 4 for feed, and 8 for receiver phase, rotatio...

  19. Treatment of phenol in synthetic saline wastewater by solvent extraction and two-phase membrane biodegradation.

    Science.gov (United States)

    Juang, Ruey-Shin; Huang, Wen-Ching; Hsu, Ya-Han

    2009-05-15

    Phenol in synthetic saline (100gL(-1) NaCl) and acidic (pH 3) wastewater was treated by a hybrid solvent extraction and two-phase membrane biodegradation process at 30 degrees C. Kerosene was adopted to be the organic solvent because it was biocompatible and had a suitable partition coefficient for phenol. Phenol in water was first extracted by kerosene in a batch stirred vessel and the loaded solvent was passed through the lumen of a polyvinylidene fluoride (PVDF) hollow-fiber membrane contactor; in the meantime, Pseudomonas putida BCRC 14365 in mineral salt medium was flowed across the shell, to which tetrasodium phyophosphate (1gL(-1)) was added as a dispersing agent. The effect of the initial phenol level in wastewater (110-2400mgL(-1)) on phenol removal and cell growth was experimentally studied. At a cell concentration of 0.023gL(-1), it was shown that the removal of phenol from saline wastewater was more efficient at a level of 2000mgL(-1) when 0.02-m(2) membrane module was used. The effects of bigger membrane module size (0.19m(2) area) and higher initial cell concentration (0.092-0.23gL(-1)) on the performance of such a hybrid process for the treatment of higher-level phenol in saline wastewater was also evaluated and discussed.

  20. Structural feature extraction protocol for classifying reversible membrane binding protein domains.

    Science.gov (United States)

    Källberg, Morten; Lu, Hui

    2009-01-01

    Machine learning based classification protocols for automated function annotation of protein structures have in many instances proven superior to simpler sequence based procedures. Here we present an automated method for extracting features from protein structures by construction of surface patches to be used in such protocols. The utility of the developed patch-growing procedure is exemplified by its ability to identify reversible membrane binding domains from the C1, C2, and PH families.

  1. The effects of alcoholic leaf extract Ocimum basilicum on angiogenesis in chick chorioallantoic membrane

    Directory of Open Access Journals (Sweden)

    Niazi Fateme

    2016-10-01

    Full Text Available Abstract Background: Angiogenesis is an important biological processes of new blood vessels in many pathological stages of development and embryo development occurs and a complex and dynamic phenomenon that is needed for development and other physiological processes. This study aimed to investigate the effect of alcoholic Ocimum basilicum leaf extract on angiogenesis chick chorioallantoic membrane is done. Materials and Methods: In this experimental study 40 Ross fertilized eggs were randomly divided into four groups: control, sham-exposed and experimental groups were divided. The second day of incubation the eggs window was opened. Eighth day of the alcoholic extract of basil doses of 50 and 150 mg/kg on chick chorioallantoic membrane was injected. On day 12, embryos length and weight and chorioallantoic membrane (CAM was photographed by photostereomicroscope Then the numbers and lengths of vessels in special area on CAM were measured with Image J. analyzed through by t-test and ANOVA (P<0.05. Results: The data does not show significant difference between embryos length and weight in sham compare to all experimental groups. In the study vessels number just with 150 mg/kg observed significant. Conclusion: Alcoholic extract of basil is an increase in the number of vessels and in this sense the healing and growth processes associated with them as well as effective.

  2. Single-Cell Chemical Lysis on Microfluidic Chips with Arrays of Microwells

    Directory of Open Access Journals (Sweden)

    Nikolay A. Maslov

    2011-12-01

    Full Text Available Many conventional biochemical assays are performed using populations of cells to determine their quantitative biomolecular profiles. However, population averages do not reflect actual physiological processes in individual cells, which occur either on short time scales or nonsynchronously. Therefore, accurate analysis at the single-cell level has become a highly attractive tool for investigating cellular content. Microfluidic chips with arrays of microwells were developed for single-cell chemical lysis in the present study. The cellular occupancy in 30-mm-diameter microwells (91.45% was higher than that in 20-mm-diameter microwells (83.19% at an injection flow rate of 2.8 mL/min. However, most of the occupied 20-mm-diameter microwells contained individual cells. The results of chemical lysis experiments at the single-cell level indicate that cell membranes were gradually lysed as the lysis buffer was injected; they were fully lysed after 12 s. Single-cell chemical lysis was demonstrated in the proposed microfluidic chip, which is suitable for high-throughput cell lysis.

  3. Micro Corona Ionizer as an Ozone Source for Bacterial Cell Lysis

    Science.gov (United States)

    Lee, Eun-Hee; Lim, Hyun Jeong; Chua, Beelee; Son, Ahjeong

    2015-04-01

    DNA extraction is a critical process of DNA assays including polymerase chain reaction (PCR), microarrays, molecular cloning, and DNA hybridization which has been well established and can be implemented by commercial kits. DNA extraction involves cell lysis, precipitation, and purification through the combination of physical and chemical processes. Cell lysis is essential to high DNA recovery yield which can be achieved via a variety of physical, chemical, and enzymatic methods. However, these methods were originally developed for bioassays that were labor intensive, time consuming, and vulnerable to contamination and inhibition. Here, we proposed to employ a micro corona ionizer as an ozone source to lyse bacterial cells. Ozone has been well known and used as a disinfectant which allows cell lysis and DNA extraction. Previously, we have shown that a micro corona ionizer is capable of generating a significant amount of ozone. In this study, we employed the micro corona ionizer for the bacterial cell lysis which consists of a 50 μm diameter cantilever wire as the discharge cathode and a 50 μm thick copper foil as anode. Applied voltages varied from 1900 to 2200 V with corresponding corona currents from 16 to 28 μA. The resultant ozone (concentration > 0.14 ppm) generated from the micro corona ionizer was bubbled into the sample via a miniature pump. We demonstrated the cell lysis of Pseudomonas putida as the target bacterium using the micro corona ionizer. At a flow rate of 38 ml/min and applied corona voltage of 2000 V, 98.5 ± 0.2% lysis (normalized to sonication result) was achieved after 10 min. In comparison, untreated and air-treated samples showed normalized % lysis of 11.9 ± 2.4 and 36.1 ± 1.7%, respectively. We also showed that the cell lysis efficiency could be significantly increased by increasing the flow rate and the applied corona voltage. By comparing the experimental results for continuous and pulsed treatment, we verified that the percentage of

  4. Streamlined Membrane Proteome Preparation for Shotgun Proteomics Analysis with Triton X-100 Cloud Point Extraction and Nanodiamond Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Minh D. Pham

    2016-05-01

    Full Text Available While mass spectrometry (MS plays a key role in proteomics research, characterization of membrane proteins (MP by MS has been a challenging task because of the presence of a host of interfering chemicals in the hydrophobic protein extraction process, and the low protease digestion efficiency. We report a sample preparation protocol, two-phase separation with Triton X-100, induced by NaCl, with coomassie blue added for visualizing the detergent-rich phase, which streamlines MP preparation for SDS-PAGE analysis of intact MP and shot-gun proteomic analyses. MP solubilized in the detergent-rich milieu were then sequentially extracted and fractionated by surface-oxidized nanodiamond (ND at three pHs. The high MP affinity of ND enabled extensive washes for removal of salts, detergents, lipids, and other impurities to ensure uncompromised ensuing purposes, notably enhanced proteolytic digestion and down-stream mass spectrometric (MS analyses. Starting with a typical membranous cellular lysate fraction harvested with centrifugation/ultracentrifugation, MP purities of 70%, based on number (not weight of proteins identified by MS, was achieved; the weight-based purity can be expected to be much higher.

  5. Preparation and characterisation of Punica granatum pericarp aqueous extract loaded chitosan-collagen-starch membrane: role in wound healing process.

    Science.gov (United States)

    Amal, B; Veena, B; Jayachandran, V P; Shilpa, Joy

    2015-05-01

    Engineered scaffolds made from natural biomaterials are crucial elements in tissue engineering strategies. In this study, biological scaffold like chitosan-collagen-starch membrane (CCSM) loaded with the antibacterial agent, Punica granatum pericarp aqueous extract was explored for enhanced regeneration of epithelial tissue during wound healing. Collagen was extracted from Rachycentron canadum fish skin. Membranous scaffold was prepared by mixing collagen, starch and chitosan in a fixed proportion, loaded with aqueous extract of P. granatum and its anti-pseudomonal activity was studied. Morphological characterization by SEM and mechanical property like tensile strength of the membrane were studied. Excision wound of 2 cm(2) size was induced in Guinea pig and the effect of P. granatum extract loaded CCSM in wound healing was studied. The SEM image showed deep pores in the membrane and also possessed good tensile strength. Wound surface area was reduced prominently in the experimental group with P. granatum extract loaded CCSM when compared to the group with unloaded membrane and the one with no membrane. Punica granatum extract loaded CCSM has antipseudomonal property and supported enhanced epithelial cell proliferation without leaving a scar after wound healing. This has significant therapeutic application in membranous scaffold mediated skin repair and regeneration.

  6. Membrane Dialysis Extraction (MDE): a novel approach for extracting toxicologically relevant hydrophobic organic compounds from soils and sediments for assessment in biotests

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, T.B.; Leist, E.; Braunbeck, T.; Hollert, H. [Dept. of Zoology, Aquatic Ecology and Toxicology, Univ. of Heidelberg (Germany); Rastall, A.C.; Erdinger, L. [Inst. of Hygiene and Medical Microbiology, Univ. of Heidelberg (Germany)

    2006-02-15

    Goal, scope and background. Organic solvents are routinely used to extract toxicants from polluted soils and sediments prior to chemical analysis or bioassay. Conventional extraction methods often require the use of heated organic solvents, in some cases under high pressure. These conditions can result in loss of volatile compounds from the sample and the degradation of thermally labile target analytes. Moreover, extracts of soils and sediments also frequently contain substantial quantities of organic macromolecules which can act as sorbing phases for target analytes and in doing so interfere with both chemical analysis and bioassays. Membrane dialysis extraction (MDE) is described as a simple, passive extraction method for selectively extracting toxicologically relevant hydrophobic organic compounds (HOCs) from polluted soils and sediments and analyzed for its applicability in ecotoxicological investigations. Methods. Toxicologically relevant hydrophobic organic compounds were extracted from wet and dry sediments by sealing replicate samples in individual lengths of pre-cleaned low-density polyethylene (LD-PE) tubing and then dialysing in n-hexane. Results. The membrane dialysis extraction was found to be at least as efficient as Soxhlet methodology to extract toxicologically relevant HOCs from sediment samples. In most cases, MDE-derived extracts showed a higher toxicological potential than the Soxhlet extracts. Lack of any significant effects in any MDE controls indicated these differences were not caused by contamination of the LD-PE membrane used. The elevated toxicological potential of MDE extracts is most likely the result of enhanced bioavailability of toxic compounds in consequence of lower amounts of organic macromolecules (i.e. sorbing phases) in the MDE extracts. This effect is probably the result of a size-selective restriction by the LD-PE membrane. Conclusion. Membrane dialysis extraction was found to be a simple, efficient and cost-effective method

  7. Flow methodology for methanol determination in biodiesel exploiting membrane-based extraction

    International Nuclear Information System (INIS)

    Araujo, Andre R.T.S.; Saraiva, M. Lucia M.F.S.; Lima, Jose L.F.C.; Korn, M. Gracas A.

    2008-01-01

    A methodology based in flow analysis and membrane-based extraction has been applied to the determination of methanol in biodiesel samples. A hydrophilic membrane was used to perform the liquid-liquid extraction in the system with the organic sample fed to the donor side of the membrane and the methanol transfer to an aqueous acceptor buffer solution. The quantification of the methanol was then achieved in aqueous solution by the combined use of immobilised alcohol oxidase (AOD), soluble peroxidase and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). The optimization of parameters such as the type of membrane, the groove volume and configuration of the membrane unit, the appropriate organic solvent, sample injection volume, as well as immobilised packed AOD reactor was performed. Two dynamic analytical working ranges were achieved, up to 0.015% and up to 0.200% (m/m) methanol concentrations, just by changing the volume of acceptor aqueous solution. Detection limits of 0.0002% (m/m) and 0.007% (m/m) methanol were estimated, respectively. The decision limit (CCα) and the detection capacity (CCβ) were 0.206 and 0.211% (m/m), respectively. The developed methodology showed good precision, with a relative standard deviation (R.S.D.) <5.0% (n = 10). Biodiesel samples from different sources were then directly analyzed without any sample pre-treatment. Statistical evaluation showed good compliance, for a 95% confidence level, between the results obtained with the flow system and those furnished by the gas chromatography reference method. The proposed methodology turns out to be more environmental friendly and cost-effective than the reference method

  8. Increased Resistance to osmotic lysis of sickled erythrocytes ...

    African Journals Online (AJOL)

    treated with CNw had significantly reduced osmotic lysis when compared with the untreated set (P<0.05, respectively) at various hypotonic NaCl concentrations. Various Hb genotypes exhibited a graded increase in osmotic pressure lysis in ...

  9. Pressurized hot water extraction followed by miniaturized membrane assisted solvent extraction for the green analysis of alkylphenols in sediments.

    Science.gov (United States)

    Salgueiro-González, N; Turnes-Carou, I; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2015-02-27

    A novel and Green analytical methodology for the determination of alkylphenols (4-tert-octylphenol, 4-n-octylphenol, 4-n-nonylphenol, nonylphenol) in sediments was developed and validated. The method was based on pressurized hot water extraction (PHWE) followed by miniaturized membrane assisted solvent extraction (MASE) and liquid chromatography-electrospray ionization tandem mass spectrometry detection (LC-ESI-MS/MS). The extraction conditions were optimized by a Plackett-Burman design in order to minimize the number of assays according to Green principles. Matrix effect was studied and compensated using deuterated labeled standards as surrogate standards for the quantitation of the target compounds. The analytical features of the method were satisfactory: relative recoveries varied between 92 and 103% and repeatability and intermediate precision were MQL) ranged from 0.061 (4-n-nonylphenol) to 1.7ngg(-1) dry weight (nonylphenol). Sensitivity, selectivity, automaticity and fastness are the main advantages of the exposed methodology. Reagent consumption, analysis time and waste generation were minimized. The "greenness" of the proposed method was evaluated using an analytical Eco-Scale approach and satisfactory results were obtained. The applicability of the proposed method was demonstrated analysing sediment samples of Galicia coast (NW of Spain) and the ubiquity of alkylphenols in the environment was demonstrated. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Rz/Rz1 lysis gene equivalents in phages of Gram-negative hosts.

    Science.gov (United States)

    Summer, Elizabeth J; Berry, Joel; Tran, Tram Anh T; Niu, Lili; Struck, Douglas K; Young, Ry

    2007-11-09

    Under usual laboratory conditions, lysis by bacteriophage lambda requires only the holin and endolysin genes, but not the Rz and Rz1 genes, of the lysis cassette. Defects in Rz or Rz1 block lysis only in the presence of high concentrations of divalent cations. The lambda Rz and Rz1 lysis genes are remarkable in that Rz1, encoding an outer membrane lipoprotein, is completely embedded in the +1 register within Rz, which itself encodes an integral inner membrane protein. While Rz and Rz1 equivalents have been identified in T7 and P2, most phages, including such well-studied classic phages as T4, P1, T1, Mu and SP6, lack annotated Rz/Rz1 equivalents. Here we report that a search strategy based primarily on gene arrangement and membrane localization signals rather than sequence similarity has revealed that Rz/Rz1 equivalents are nearly ubiquitous among phages of Gram-negative hosts, with 120 of 137 phages possessing genes that fit the search criteria. In the case of T4, a deletion of a non-overlapping gene pair pseT.2 and pseT.3 identified as Rz/Rz1 equivalents resulted in the same divalent cation-dependent lysis phenotype. Remarkably, in T1 and six other phages, Rz/Rz1 pairs were not found but a single gene encoding an outer membrane lipoprotein with a C-terminal transmembrane domain capable of integration into the inner membrane was identified. These proteins were named "spanins," since their protein products are predicted to span the periplasm providing a physical connection between the inner and outer membranes. The T1 spanin gene was shown to complement the lambda Rz-Rz1- lysis defect, indicating that spanins function as Rz/Rz1 equivalents. The widespread presence of Rz/Rz1 or their spanin equivalents in phages of Gram-negative hosts suggests a strong selective advantage and that their role in the ecology of these phages is greater than that inferred from the mild laboratory phenotype.

  11. Selective extraction of uranium (VI) and thorium (IV) ions by liquid membrane technique

    International Nuclear Information System (INIS)

    Guey, N.; Cetisli, H.; Donat, R.

    2009-01-01

    Liquid membrane processes have a great importance for wastewater treatment, chemical engineering, and hydrometallurgy, biotechnological and biomedical applications. Liquid membrane process, one of the separation and purification techniques which are used for removal of the some metals and compounds causing environment and water pollution reduces the quantity of requirement of the solvents, prevents the environment pollution and becomes more economical as it combines extraction and stripping processes in one step. As uranium and thorium metals damage the environment and people's health, selective separation and refining processes will be useful for both the aspects of scientific and industrial applications. Because of trace amount and their radioactive structure, the industrial effects of recovering of both uranium and thorium or reducing the dangerous environmental effects, have a great importance. In this study, the function of transporting of uranium and thorium ions from aqueous solutions to the organic solutions and following, from organic solutions to aqueous solutions; the parameters of extraction technique and solvent type, solution of the pH, temperature, stirring speed, concentration of ions, concentration of reagent are investigated.The use of modelled system by supervisors is analyzed for the constant recovery application of related metals at the most effective conditions decided by the use of liquid membrane technique.

  12. Calorimetric Quantification of Cyclodextrin-Mediated Detergent Extraction for Membrane-Protein Reconstitution.

    Science.gov (United States)

    Textor, Martin; Keller, Sandro

    2016-01-01

    For many in vitro studies, purified membrane proteins need to be reconstituted from detergent micelles into lipid bilayers to regain their native structures and functions. Stoichiometric complexation of detergent by cyclodextrin provides a tightly controllable strategy for detergent extraction. Here, we describe a practical approach making use of isothermal titration calorimetry to obtain a complete set of thermodynamic parameters that allows for quantitative prediction of the transition from micelles to bilayer membranes during reconstitution. These parameters include the dissociation constant of the cyclodextrin/detergent inclusion complex, the critical micellar concentration of the detergent, and the phase boundaries of the lipid/detergent phase diagram. The underlying theoretical framework involves linked equilibria among all pseudophases, as described previously (Textor, Vargas, & Keller, 2015). This chapter focuses on practical aspects of the approach and discusses caveats and calorimetry-specific details of data analysis. With the entire parameter set at hand, exploration of different reconstitution trajectories within the lipid/detergent phase diagram is possible. Together with the straightforward control over the rate of detergent extraction offered by cyclodextrin complexation, this opens the possibility of systematically tuning and optimizing the reconstitution process of membrane proteins. Provided some particular precautions are taken, the approach can be adapted to many other combinations of proteins, lipids, detergents, and cyclodextrins. © 2016 Elsevier Inc. All rights reserved.

  13. Comparison of lysis-centrifugation with lysis-filtration and a conventional unvented bottle for blood cultures.

    OpenAIRE

    Gill, V J; Zierdt, C H; Wu, T C; Stock, F; Pizzo, P A; MacLowry, J D

    1984-01-01

    Evaluation of a commercially available lysis-centrifugation blood culture system (Isolator, DuPont Co., Wilmington, Del.) and a lysis-filtration blood culture system for 3,111 cultures showed that both methods had comparable recoveries (73 and 68%, respectively) of significant aerobic and facultatively anaerobic isolates. The unvented conventional blood culture bottle had a recovery rate of 59%. Although the lysis-centrifugation and lysis-filtration systems had comparable recoveries of pathog...

  14. The Influence of Extractant TOA, Stirring Time on the Extraction ProcessLiquid-liquid, and Liquid Membrane on the Liquid Wastes Containing Cd

    International Nuclear Information System (INIS)

    Prayitno; Djoko-Sardjono; Nurimaniwati; Adhe-Helmayani

    2000-01-01

    The influence of extractant and stirring time on the reduction componentcadmium on liquid wastes has been investigated. The method of experimentalused the extraction with liquid membrane emulsion. The parameters to beinvestigated were extractant amount tri-n octylamine (TOA), duration ofstirring time. In this investigated, extractant amount was varied from 5 to25 % (v/v) TOA, duration of stirring time varied from 5 to minutes. Theresult of experimental can be concluded that the best condition obtained forreducing cadmium component was on extractant amount 20 % (v/v) TOA, stirringtime 25 minutes. The best condition for reducing the cadmium component wasefficiency factor 98.35%. (author)

  15. Viability in the production of a drug extracted from Ananas comosus by a flat membrane system

    Directory of Open Access Journals (Sweden)

    Francisco Luiz Gumes Lopes

    2012-06-01

    Full Text Available The aim of this work was to study the production of e bromelain from the Ananas comosus L. Merril, by determining the process conditions using flat membranes. The production system modeling generated a hyperbolical curve and the optimization by response surfaces showed an influence of the transmembrane pressure higher than the pH influence. The cost of the production of bromelain from A. comosus was estimated 9 to 13 times lower than Sigma's retail sales price and 6.5 to 8.5 times lower than when this enzyme was obtained through a liquid-liquid extraction, which showed the economical feasibility of the process.

  16. Simultaneous micro-electromembrane extractions of anions and cations using multiple free liquid membranes and acceptor solutions

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2016-01-01

    Roč. 908, FEB (2016), s. 113-120 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : free liquid membranes * micro-electromembrane extraction * simultaneous extractions Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 4.950, year: 2016

  17. Oversampling method to extract excitatory and inhibitory conductances from single-trial membrane potential recordings.

    Science.gov (United States)

    Bédard, Claude; Béhuret, Sebastien; Deleuze, Charlotte; Bal, Thierry; Destexhe, Alain

    2012-09-15

    Variations of excitatory and inhibitory conductances determine the membrane potential (V(m)) activity of neurons, as well as their spike responses, and are thus of primary importance. Methods to estimate these conductances require clamping the cell at several different levels of V(m), thus making it impossible to estimate conductances from "single trial" V(m) recordings. We present here a new method that allows extracting estimates of the full time course of excitatory and inhibitory conductances from single-trial V(m) recordings. This method is based on oversampling of the V(m). We test the method numerically using models of increasing complexity. Finally, the method is evaluated using controlled conductance injection in cortical neurons in vitro using the dynamic-clamp technique. This conductance extraction method should be very useful for future in vivo applications. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. On-chip cell lysis by antibacterial non-leaching reusable quaternary ammonium monolithic column.

    Science.gov (United States)

    Aly Saad Aly, Mohamed; Gauthier, Mario; Yeow, John

    2016-02-01

    Reusable antibacterial non-leaching monolithic columns polymerized in microfluidic channels designed for on-chip cell lysis applications were obtained by the photoinitiated free radical copolymerization of diallyldimethylammonium chloride (DADMAC) and ethylene glycol diacrylate (EGDA) in the presence of a porogenic solvent. The microfluidic channels were fabricated in cross-linked poly(methyl methacrylate) (X-PMMA) substrates by laser micromachining. The monolithic columns have the ability to inhibit the growth of, kill and efficiently lyse Gram-positive Micrococcus luteus (Schroeter) (ATCC 4698) and Kocuria rosea (ATCC 186), and Gram-negative bacteria Pseudomonas putida (ATCC 12633) and Escherichia coli (ATCC 35218) by mechanically shearing the bacterial membrane when forcing the cells to pass through the narrow pores of the monolithic column, and simultaneously disintegrating the cell membrane by physical contact with the antibacterial surface of the column. Cell lysis was confirmed by off-chip PCR without the need for further purification. The influence of the cross-linking monomer on bacterial growth inhibition, leaching, lysis efficiency of the monolithic column and its mechanical stability within the microfluidic channel were investigated and analyzed for three different cross-linking monomers: ethylene glycol dimethacrylate (EGDA), ethylene glycol dimethacrylate (EGDMA) and 1,6-hexanediol dimethacrylate (1,6-HDDMA). Furthermore, the bonding efficiency of two X-PMMA substrates with different cross-linking levels was studied. The monolithic columns were shown to be stable, non-leaching, and reusable for over 30 lysis cycles without significant performance degradation or DNA carryover when they were back-flushed between lysis cycles.

  19. A New Emulsion Liquid Membrane Based on a Palm Oil for the Extraction of Heavy Metals

    Directory of Open Access Journals (Sweden)

    Sanna Björkegren

    2015-04-01

    Full Text Available The extraction efficiency of hexavalent chromium, Cr(VI, from water has been investigated using a vegetable oil based emulsion liquid membrane (ELM technique. The main purpose of this study was to create a novel ELM formulation by choosing a more environmentally friendly and non-toxic diluent such as palm oil. The membrane phase so formulated includes the mobile carrier tri-n-octylmethylammonium chloride (TOMAC, to facilitate the metal transport, and the hydrophilic surfactant Tween 80 to facilitate the dispersion of the ELM phase in the aqueous solution. Span 80 is used as surfactant and butanol as co-surfactant. Our results demonstrate that this novel ELM formulation, using the vegetable palm oil as diluent, is useful for the removal of hexavalent chromium with an efficiency of over 99% and is thus competitive with the already existing, yet less environmentally friendly, ELM formulations. This result was achieved with an optimal concentration of 0.1 M NaOH as stripping agent and an external phase pH of 0.5. Different water qualities have also been investigated showing that the type of water (deionized, distilled, or tap water does not significantly influence the extraction rate.

  20. Parallel artificial liquid membrane extraction as an efficient tool for removal of phospholipids from human plasma.

    Science.gov (United States)

    Ask, Kristine Skoglund; Bardakci, Turgay; Parmer, Marthe Petrine; Halvorsen, Trine Grønhaug; Øiestad, Elisabeth Leere; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2016-09-10

    Generic Parallel Artificial Liquid Membrane Extraction (PALME) methods for non-polar basic and non-polar acidic drugs from human plasma were investigated with respect to phospholipid removal. In both cases, extractions in 96-well format were performed from plasma (125μL), through 4μL organic solvent used as supported liquid membranes (SLMs), and into 50μL aqueous acceptor solutions. The acceptor solutions were subsequently analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) using in-source fragmentation and monitoring the m/z 184→184 transition for investigation of phosphatidylcholines (PC), sphingomyelins (SM), and lysophosphatidylcholines (Lyso-PC). In both generic methods, no phospholipids were detected in the acceptor solutions. Thus, PALME appeared to be highly efficient for phospholipid removal. To further support this, qualitative (post-column infusion) and quantitative matrix effects were investigated with fluoxetine, fluvoxamine, and quetiapine as model analytes. No signs of matrix effects were observed. Finally, PALME was evaluated for the aforementioned drug substances, and data were in accordance with European Medicines Agency (EMA) guidelines. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Parallel artificial liquid membrane extraction of new psychoactive substances in plasma and whole blood.

    Science.gov (United States)

    Vårdal, Linda; Askildsen, Hilde-Merete; Gjelstad, Astrid; Øiestad, Elisabeth Leere; Edvardsen, Hilde Marie Erøy; Pedersen-Bjergaard, Stig

    2017-03-24

    Parallel artificial liquid membrane extraction (PALME) was combined with ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) and the potential for screening of new psychoactive substances (NPS) was investigated for the first time. PALME was performed in 96-well format comprising a donor plate, a supported liquid membrane (SLM), and an acceptor plate. Uncharged NPS were extracted from plasma or whole blood, across an organic SLM, and into an aqueous acceptor solution, facilitated by a pH gradient. MDAI (5,6-methylenedioxy-2-aminoindane), methylone, PFA (para-fluoroamphetamine), mCPP (meta-chlorophenylpiperazine), pentedrone, methoxetamine, MDPV (methylenedioxypyrovalerone), ethylphenidate, 2C-E (2,5-dimethoxy-4-ethylphenethylamine), bromo-dragonfly, and AH-7921 (3,4-dichloro-N-{[1-(dimethylamino)cyclohexyl]methyl}benzamide) were selected as representative NPS. Optimization of operational parameters was necessary as the NPS were novel to PALME, and because PALME was performed from whole blood for the very first time. In the PALME method developed for plasma, NPS were extracted from a 250μL alkalized donor solution consisting of 125μL plasma sample, 115μL 40mM NaOH, and 10μL internal standard. In the PALME method from whole blood, the 250μL alkalized donor solution consisted of 100μL whole blood, 50μL deionized water, 75μL 80mM NaOH, and 25μL internal standard. In both methods, extraction was accomplished across an SLM of 5μL dodecyl acetate with 1% trioctylamine (w/w), and further into an acidic acceptor solution of 50μL 20mM formic acid. The extraction was promoted by agitation at 900rpm and was carried out for 120min. Method validation was performed and the following parameters were considered: linearity, limits of quantification (LOQ), intra- and inter-day precision, accuracy, extraction recoveries, carry-over, and matrix effects. The validation results were in accordance with FDA guidelines. Copyright © 2017 Elsevier B.V. All

  2. CFD simulation of copper(II) extraction with TFA in non-dispersive hollow fiber membrane contactors.

    Science.gov (United States)

    Muhammad, Amir; Younas, Mohammad; Rezakazemi, Mashallah

    2018-01-27

    This study presents computational fluid dynamics (CFD) simulation of dispersion-free liquid-liquid extraction of copper(II) with trifluoroacetylacetone (TFA) in hollow fiber membrane contactor (HFMC). Mass and momentum balance Navier-Stokes equations were coupled to address the transport of copper(II) solute across membrane contactor. Model equations were simulated using COMSOL Multiphysics™. The simulation was run to study the detailed concentration distribution of copper(II) and to investigate the effects of various parameters like membrane characteristics, partition coefficient, and flow configuration on extraction efficiency. Once-through extraction was found to be increased from 10 to 100% when partition coefficient was raised from 1 to 10. Similarly, the extraction efficiency was almost doubled when porosity to tortuosity ratio of membrane was increased from 0.05 to 0.81. Furthermore, the study revealed that CFD can be used as an effective optimization tool for the development of economical membrane-based dispersion-free extraction processes.

  3. Microporous Carbon Spheres Solid Phase Membrane Tip Extraction for the Analysis of Nitrosamines in Water Samples

    International Nuclear Information System (INIS)

    Mohammed Salisu Musa; Wan Aini Wan Ibrahim

    2015-01-01

    A simple solid phase membrane tip extraction (SPMTE) utilizing microporous carbon spheres (MCS) was developed for the analysis of nitrosamines in aqueous samples. The method termed MCS-SPMTE was optimized for various important extraction parameters namely conditioning organic solvent, extraction time, effects of salt addition and pH change, desorption time, desorption solvent and sample volume. Under the optimized conditions, the method indicated good linearity in the range of 10-100 μg/ L with coefficients of determination, r 2 ≥0.9984. The method also demonstrated good reproducibility with % RSDs values ranging from 2.2 - 8.9 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) for the method ranged from 3.2 - 4.8 μg/ L and 10.9 - 15.9 μg/L respectively. Recoveries for both tap-water and lake water samples spiked at 10 μg/L were in the range of 83.2 - 107.5 %. (author)

  4. Membrane stability of sickle erythrocytes incubated in extracts of three medicinal plants: Anacardium occidentale, Psidium guajava, and Terminalia catappa.

    Science.gov (United States)

    Chikezie, Paul Chidoka; Uwakwe, Augustine Amadikwa

    2011-04-01

    Many reports showed that medicinal plant extracts cause alterations on the shape and physiology of erythrocytes. The present study seeks to ascertain the osmotic stability of sickle erythrocytes incubated in aqueous extracts of Anacardium occidentale, Psidium guajava, and Terminalia catappa. The fraction of erythrocytes lysed when suspended in saline solution of varying concentrations was investigated by spectrophotometric method. The percentage hemolysis of erythrocytes in the control and test samples showed a sigmoidal relationship with increasing concentrations of saline solution. Membrane stability was ascertained as mean corpuscular fragility (MCF) index of erythrocytes incubated in 400 and 800 mg/dL aqueous concentrations of the three plant extracts. The two experimental concentrations of P. guajava and T. catappa protected the erythrocytes against osmotic stress, as evidenced by decreases in the values of MCF compared with the control sample (P catappa stabilized erythrocyte membrane, higher concentration (800 mg/dL) of A. occidentale exhibited no membrane protective effect.

  5. Immobilization and release study of a red alga extract in hydrogel membranes

    International Nuclear Information System (INIS)

    Amaral, Renata Hage

    2009-01-01

    In pharmaceutical technology hydrogel is the most used among the polymeric matrices due to its wide application and functionality, primarily in drug delivery system. In view of the large advance innovations in cosmetic products, both through the introduction of new active agents as the matrices used for its controlled release, the objective of this study was to evaluate the release and immobilization of a natural active agent, the Arct'Alg in hydrogel membranes to obtain a release device for cosmetics. Arct'Alg is an aqueous extract which has excellent anti-oxidant, lipolytic, anti-inflammatory and cytostimulant action. Study on mechanical and physical-chemical properties and biocompatibility in vitro of hydrogel membranes of poly(vinyl-2- pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) obtained by ionizing radiation crosslinking have been performed. The physical-chemical characterization of polymeric matrices was carried out by gel fraction and swelling tests and biocompatibility by in vitro test of cytotoxicity by using the technique of neutral red incorporation. In the gel fraction test, both the PVP and PVA hydrogel showed a high crosslinking degree. The PVP hydrogel showed a greater percentage of swelling in relation to PVA and the cytotoxicity test of the hydrogels showed non-toxicity effect. The cytostimulation property of Arct'Alg was verified by the cytostimulation test with rabbit skin cells, it was showed an increase at about 50% of the cells when in contact with 0,5% of active agent. The hydrogel membranes prepared with 3% of Arct'Alg were subjected to the release test in an incubator at 37 degree C and aliquots collected during the test were quantified by high performance liquid chromatography (HPLC). The results obtained in the kinetics of release showed that the PVP hydrogel membranes released about 50% of Arct'Alg incorporated and the PVA hydrogel membranes at about 30%. In the cytostimulation test of released Arct'Alg, the PVP device showed an

  6. Pressure-mediated reduction of ultrasonically induced cell lysis

    International Nuclear Information System (INIS)

    Ciaravino, V.E.; Miller, M.W.; Carstensen, E.L.

    1981-01-01

    Chinese hamster V-79 cells, exposed in polystyrene tubes for 5 min to 1-MHz continuous-wave ultrasound, were lysed more by a 10 than a 5 W/cm 2 intensity. Higher atmospheric pressure was needed to eliminate lysis with the former relative to the latter intensity, but lysis by 10 W/cm 2 was completely climinated with 2 atm of hydrostatic pressure. The reduction in lysis per unit increase in atmospheric pressure was comparable for both ultrasound intensities

  7. Evaluation of different organophosphorous extractants for uranium permeation from nitric acid medium across a supported liquid membrane

    International Nuclear Information System (INIS)

    Sujoy, Biswas; Roy, S.B.; Pal, Sangita; Tewari, P.K.; Pathak, P.N.; Manchanda, V.K.

    2011-01-01

    Uranium permeation studies from nitric acid medium across a supported liquid membrane were carried out employing different acidic organophosphorous extractants viz. Cyanex 272, PC88A, DNPPA either alone or in combination with neutral donors such as TBP, TEHP, TOPO, and Cyanex 923. H 2 SO 4 solution was used as a receiver phase. Effect of various parameters like effect of various acidic extractants, presence of neutral donors as well as nature of receiver phase on uranium transport across supported liquid membrane were investigated. (author)

  8. Electromembrane extraction with alkylated phosphites and phosphates as supported liquid membranes

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2017-01-01

    A range of alkylated phosphates and phosphites were for the first time investigated as potential supported liquid membranes (SLMs) for electromembrane extraction (EME) of basic drugs from human plasma samples. Six polar basic drugs were used as model analytes for initial testing of the different...... on this observation, hydrogen-bonding interactions were hypothesized to play a dominant role in the partition of the charged polar model analytes into the SLM. The successful solvents also contained alkyl moieties equivalent to 12–18 carbon atoms. Interestingly, similar phosphates/phosphites with aromatic character...... were unsuccessful. Alkylated phosphates/phosphites with less carbon atoms resulted in high current flowing in the system, whereas similar structures with >18 carbon atoms provided very low recoveries and extremely low system-current. Based on this knowledge, an SLM of TBP mixed with 40% NPOE (2...

  9. Dynein-Based Accumulation of Membranes Regulates Nuclear Expansion in Xenopus laevis Egg Extracts.

    Science.gov (United States)

    Hara, Yuki; Merten, Christoph A

    2015-06-08

    Nuclear size changes dynamically during development and has long been observed to correlate with the space surrounding the nucleus, as well as with the volume of the cell. Here we combine an in vitro cell-free system of Xenopus laevis egg extract with microfluidic devices to systematically analyze the effect of spatial constraints. The speed of nuclear expansion depended on the available space surrounding the nucleus up to a threshold volume in the nanoliter range, herein referred to as the nuclear domain. Under spatial constraints smaller than this nuclear domain, the size of microtubule-occupied space surrounding the nucleus turned out to be limiting for the accumulation of membranes around the nucleus via the motor protein dynein, therefore determining the speed of nuclear expansion. This mechanism explains how spatial information surrounding the nucleus, such as the positioning of the nucleus inside the cell, can control nuclear expansion. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Flip-flop of phospholipids in proteoliposomes reconstituted from detergent extract of chloroplast membranes: kinetics and phospholipid specificity.

    Directory of Open Access Journals (Sweden)

    Archita Rajasekharan

    Full Text Available Eukaryotic cells are compartmentalized into distinct sub-cellular organelles by lipid bilayers, which are known to be involved in numerous cellular processes. The wide repertoire of lipids, synthesized in the biogenic membranes like the endoplasmic reticulum and bacterial cytoplasmic membranes are initially localized in the cytosolic leaflet and some of these lipids have to be translocated to the exoplasmic leaflet for membrane biogenesis and uniform growth. It is known that phospholipid (PL translocation in biogenic membranes is mediated by specific membrane proteins which occur in a rapid, bi-directional fashion without metabolic energy requirement and with no specificity to PL head group. A recent study reported the existence of biogenic membrane flippases in plants and that the mechanism of plant membrane biogenesis was similar to that found in animals. In this study, we demonstrate for the first time ATP independent and ATP dependent flippase activity in chloroplast membranes of plants. For this, we generated proteoliposomes from Triton X-100 extract of intact chloroplast, envelope membrane and thylakoid isolated from spinach leaves and assayed for flippase activity using fluorescent labeled phospholipids. Half-life time of flipping was found to be 6 ± 1 min. We also show that: (a intact chloroplast and envelope membrane reconstituted proteoliposomes can flip fluorescent labeled analogs of phosphatidylcholine in ATP independent manner, (b envelope membrane and thylakoid reconstituted proteoliposomes can flip phosphatidylglycerol in ATP dependent manner, (c Biogenic membrane ATP independent PC flipping activity is protein mediated and (d the kinetics of PC translocation gets affected differently upon treatment with protease and protein modifying reagents.

  11. Mechanism of Aloe Vera extract protection against UVA: shelter of lysosomal membrane avoids photodamage.

    Science.gov (United States)

    Rodrigues, Daniela; Viotto, Ana Cláudia; Checchia, Robert; Gomide, Andreza; Severino, Divinomar; Itri, Rosangela; Baptista, Maurício S; Martins, Waleska Kerllen

    2016-03-01

    The premature aging (photoaging) of skin characterized by wrinkles, a leathery texture and mottled pigmentation is a well-documented consequence of exposure to sunlight. UVA is an important risk factor for human cancer also associated with induction of inflammation, immunosuppression, photoaging and melanogenesis. Although herbal compounds are commonly used as photoprotectants against the harmful effects of UVA, the mechanisms involved in the photodamage are not precisely known. In this study, we investigated the effects of Aloe Vera (Aloe barbadensis mil) on the protection against UVA-modulated cell killing of HaCaT keratinocytes. Aloe Vera exhibited the remarkable ability of reducing both in vitro and in vivo photodamage, even though it does not have anti-radical properties. Interestingly, the protection conferred by Aloe Vera was associated with the maintenance of membrane integrity in both mimetic membranes and intracellular organelles. The increased lysosomal stability led to a decrease in lipofuscinogenesis and cell death. This study explains why Aloe Vera extracts offer protection against photodamage at a cellular level in both the UV and visible spectra, leading to its beneficial use as a supplement in protective dermatological formulations.

  12. Electronic simulation of the supported liquid membrane in electromembrane extraction systems: Improvement of the extraction by precise periodical reversing of the field polarity

    International Nuclear Information System (INIS)

    Moazami, Hamid Reza; Nojavan, Saeed; Zahedi, Pegah; Davarani, Saied Saeed Hosseiny

    2014-01-01

    Highlights: • A simple equivalent circuit has been proposed for a supported liquid membrane. • A dual charge transfer mechanism was proposed for electromembrane extraction. • An improvement was observed by precise periodical reversing of the field polarity. - Abstract: In order to understand the limitations of electromebrane extraction procedure better, a simple equivalent circuit has been proposed for a supported liquid membrane consisting of a resistor and a low leakage capacitor in series. To verify the equivalent circuit, it was subjected to a simulated periodical polarity changing potential and the resulting time variation of the current was compared with that of a real electromembrane extraction system. The results showed a good agreement between the simulated current patterns and those of the real ones. In order to investigate the impact of various limiting factors, the corresponding values of the equivalent circuit were estimated for a real electromembrane extraction system and were attributed to the physical parameters of the extraction system. A dual charge transfer mechanism was proposed for electromembrane extraction by combining general migration equation and fundamental aspects derived from the simulation. Dual mechanism comprises a current dependent contribution of analyte in total current and could support the possibility of an improvement in performance of an electromembrane extraction by application of an asymmetric polarity changing potential. The optimization of frequency and duty cycle of the asymmetric polarity exchanging potential resulted in a higher recovery (2.17 times greater) in comparison with the conventional electromebrane extraction. The simulation also provided more quantitative approaches toward the investigation of the mechanism of extraction and contribution of different limiting factors in electromembrane extraction. Results showed that the buildup of the double layer is the main limiting factor and the Joule heating has

  13. Prediction of the Passive Intestinal Absorption of Medicinal Plant Extract Constituents with the Parallel Artificial Membrane Permeability Assay (PAMPA).

    Science.gov (United States)

    Petit, Charlotte; Bujard, Alban; Skalicka-Woźniak, Krystyna; Cretton, Sylvian; Houriet, Joëlle; Christen, Philippe; Carrupt, Pierre-Alain; Wolfender, Jean-Luc

    2016-03-01

    At the early drug discovery stage, the high-throughput parallel artificial membrane permeability assay is one of the most frequently used in vitro models to predict transcellular passive absorption. While thousands of new chemical entities have been screened with the parallel artificial membrane permeability assay, in general, permeation properties of natural products have been scarcely evaluated. In this study, the parallel artificial membrane permeability assay through a hexadecane membrane was used to predict the passive intestinal absorption of a representative set of frequently occurring natural products. Since natural products are usually ingested for medicinal use as components of complex extracts in traditional herbal preparations or as phytopharmaceuticals, the applicability of such an assay to study the constituents directly in medicinal crude plant extracts was further investigated. Three representative crude plant extracts with different natural product compositions were chosen for this study. The first extract was composed of furanocoumarins (Angelica archangelica), the second extract included alkaloids (Waltheria indica), and the third extract contained flavonoid glycosides (Pueraria montana var. lobata). For each medicinal plant, the effective passive permeability values Pe (cm/s) of the main natural products of interest were rapidly calculated thanks to a generic ultrahigh-pressure liquid chromatography-UV detection method and because Pe calculations do not require knowing precisely the concentration of each natural product within the extracts. The original parallel artificial membrane permeability assay through a hexadecane membrane was found to keep its predictive power when applied to constituents directly in crude plant extracts provided that higher quantities of the extract were initially loaded in the assay in order to ensure suitable detection of the individual constituents of the extracts. Such an approach is thus valuable for the high

  14. Comparison of membrane-protective activity of antioxidants quercetine and Gratiola Officinalis L. extract under conditions of photodynamic haemolysis

    Science.gov (United States)

    Tkachenko, N. V.; Bykova, E. V.; Pravdin, A. B.; Navolokin, N. A.; Polukonova, N. V.; Bucharskaya, A. B.; Mudrak, D. A.; Prilepskii, A. Y.

    2016-04-01

    In the present work the effectiveness of antioxidants quercetine (a pure chemical) and Gratiola officinalis extract, which is obtained by a new method of extraction from plant material, is investigated on the model of photodynamic haemolysis that is a rather convenient method to monitor the rate of cell membranes oxidative destruction. The effect of these antioxidants on the rate of photodynamic haemolysis is considered as a measure of membranoprotective efficiency.

  15. Superiority of SDS lysis over saponin lysis for direct bacterial identification from positive blood culture bottle by MALDI-TOF MS.

    Science.gov (United States)

    Caspar, Yvan; Garnaud, Cécile; Raykova, Mariya; Bailly, Sébastien; Bidart, Marie; Maubon, Danièle

    2017-05-01

    Fast species diagnosis has an important health care impact, as rapid and specific antibacterial therapy is of clear benefit for patient's outcome. Here, a new protocol for species identification directly from positive blood cultures is proposed. Four in-house protocols for bacterial identification by MS directly from clinical positive blood cultures evaluating two lytic agents, SDS and saponin, and two protein extraction schemes, fast (FP) and long (LP) are compared. One hundred and sixty-eight identification tests are carried out on 42 strains. Overall, there are correct identifications to the species level in 90% samples for the SDS-LP, 60% for the SDS-FP, 48% for the saponin LP, and 43% for the saponin FP. Adapted scores allowed 92, 86, 72, and 53% identification for SDS-LP, SDS-FP, saponin LP, and saponin FP, respectively. Saponin lysis is associated with a significantly lower score compared to SDS (0.87 [0.83-0.92], p-value SDS lysis instead of saponin lysis and the application of this rapid and cost-effective protocol in daily routine for microbiological agents implicated in septicemia. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Comparative evaluation of actinide ion uptake by polymer inclusion membranes containing TODGA as the carrier extractant.

    Science.gov (United States)

    Mahanty, B N; Raut, D R; Mohapatra, P K; Das, D K; Behere, P G; Afzal, Md

    2014-06-30

    Polymer inclusion membranes (PIM) containing TODGA (N,N,N',N'-tetra-n-octyl diglycolamide) were evaluated for the separation of actinide ions such as Am(3+), Pu(4+), UO2(2+) and Th(4+) from acidic feeds. The PIMs were prepared using cellulose triacetate (CTA) as the polymer matrix and 2-nitrophenyloctyl ether (NPOE) as the plasticizer along with the diglycolamide carrier extractants and were characterized by conventional techniques such as XRD, thermal analysis and AFM. The PIM composition was optimized by a series of studies which involved variation in the CTA, NPOE and carrier concentration which suggested 58% TODGA, 30% NPOE and 12% CTA to be optimum. The uptake studies were carried out using feed solutions containing varying concentrations of nitric acid and showed the trend: Am(3+)>Pu(4+)>Th(4+)>UO2(2+). Transport studies were carried out in a two-compartment cell where nitric acid concentration the feed was varied (1-3M) while the receiver compartment contained alpha-hydroxy-iso-butyric acid (AHIBA). The actinide ion transport efficiencies with TODGA containing PIMs followed the same trend as seen in the uptake studies. The AFM patterns of the PIMs changed when loaded with Eu(3+) carrier (used as a surrogate for Am(3+)) while the regenerated membranes have displayed comparable morphologies. Diffusion coefficient values were experimentally obtained from the transport studies and were found to be 8.89×10(-8) cm(2)/s for Am(3+) transport. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Rubidium extraction from seawater brine by an integrated membrane distillation-selective sorption system.

    Science.gov (United States)

    Naidu, Gayathri; Jeong, Sanghyun; Johir, Md Abu Hasan; Fane, Anthony G; Kandasamy, Jaya; Vigneswaran, Saravanamuthu

    2017-10-15

    The ultimate goal of seawater reverse osmosis (SWRO) brine management is to achieve minimal liquid discharge while recovering valuable resources. The suitability of an integrated system of membrane distillation (MD) with sorption for the recovery of rubidium (Rb + ) and simultaneous SWRO brine volume reduction has been evaluated for the first time. Polymer encapsulated potassium copper hexacyanoferrate (KCuFC(PAN)) sorbent exhibited a good selectivity for Rb + sorption with 10-15% increment at 55 °C (Langmuir Q max  = 125.11 ± 0.20 mg/g) compared to at 25 °C (Langmuir Q max  = 108.71 ± 0.20 mg/g). The integrated MD-KCuFC(PAN) system with periodic membrane cleaning, enabled concentration of SWRO brine to a volume concentration factor (VCF) of 2.9 (65% water recovery). A stable MD permeate flux was achieved with good quality permeate (conductivity of 15-20 μS/cm). Repeated cycles of MD-KCuFC(PAN) sorption with SWRO brine enabled the extraction of 2.26 mg Rb + from 12 L of brine (equivalent to 1.9 kg of Rb/day, or 0.7 tonne/yr from a plant producing 10,000 m 3 /day brine). KCuFC(PAN) showed a high regeneration and reuse capacity. NH 4 Cl air stripping followed by resorcinol formaldehyde (RF) resin filtration enabled to recover Rb + from the desorbed solution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Development and optimisation of a novel three-way extraction technique based on a combination of Soxhlet extraction, membrane assisted solvent extraction and a molecularly imprinted polymer using sludge polycyclic aromatic hydrocarbons as model compounds.

    Science.gov (United States)

    Ncube, Somandla; Lekoto, Goitsemang; Cukrowska, Ewa; Chimuka, Luke

    2018-02-01

    A novel technique that integrates extraction and clean-up into a single step format is reported as part of the search for new sample preparation techniques in the analysis of persistent organic pollutants from complex samples. This was achieved by combining the extraction efficiency of the Soxhlet extractor, the selectivity of a size exclusion membrane and the specificity of a molecularly imprinted polymer for the extraction of polycyclic aromatic hydrocarbons from wastewater sludge followed by quantitation using gas chromatography with time-of-flight mass spectrometry. The approach is described as the Soxhlet extraction membrane-assisted solvent extraction molecularly imprinted polymer technique. This technique was optimised for various parameters such as extraction solvent, reflux time and membrane acceptor phase. The applicability of the developed technique was optimised using a wastewater sludge certified reference material and then tested on real wastewater sludge samples. The method detection limits ranged from 0.14 to 12.86 ng/g with relative standard deviation values for the extraction of the 16 US-EPA priority polycyclic aromatic hydrocarbons from wastewater sludge samples ranging from 0.78 to 18%. The extraction process was therefore reproducible and showed remarkable selectivity. The developed technique is a promising prospect that can be applied in the analysis of organic pollutants from complex solid samples. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Application of ACD/LABS 12 program for determination of conditions for experimental membrane extraction of pesticides

    Directory of Open Access Journals (Sweden)

    Đorđević J.

    2010-01-01

    Full Text Available This paper analyzes the conditions for membrane extraction of pesticides using ACD / LABS 12 program. The program contains a large database of more than 2000 compounds and their ionized species, for determining the pKa, further analysis includes 600 new compounds confirmed by Hammett’s equation, which gives more precise values for logD and solubility. The 16 pesticides of different classes (organophosphates, carbamates, carbamidas, neonicotinoids etc. and polarities commonly used in Serbia were examined. The program is used to calculate logD, pKa and solubility at different pH values for the mixture of pesticides. Based on the calculated values, the conditions for the extraction of pesticides in water using two-phase liquid-liquid membrane extraction were optimized.

  20. Method and apparatus for iterative lysis and extraction of algae

    Science.gov (United States)

    Chew, Geoffrey; Boggs, Tabitha; Dykes, Jr., H. Waite H.; Doherty, Stephen J.

    2015-12-01

    A method and system for processing algae involves the use of an ionic liquid-containing clarified cell lysate to lyse algae cells. The resulting crude cell lysate may be clarified and subsequently used to lyse algae cells. The process may be repeated a number of times before a clarified lysate is separated into lipid and aqueous phases for further processing and/or purification of desired products.

  1. Membrane solid-phase extraction: Field application for isolation of polycyclic aromatic hydrocarbons from water samples

    International Nuclear Information System (INIS)

    Furlong, E.T.; Koleis, J.C.; Gates, P.M.

    1995-01-01

    Solid-phase extraction (SPE) membranes (M-SPE) were used to isolate microgram-per-liter to nanogram-per-liter quantities of polycyclic aromatic hydrocarbons (PAH) in 4- to 8-liter ground-water samples from a crude-oil-contaminated ground-water site near Bemidji, Minnesota. The M-SPE method was evaluated (1) under laboratory conditions using reagent water fortified with individual PAH at 1.23 micrograms per liter, and (2) at the Bemidji site. At the site, ground-water samples were processed and PAH isolated using a M-SPE system connected directly to the well pump. Following sample isolation, all M-SPE samples were extracted using dichloromethane and analyzed by gas chromatography-mass spectrometry with selected-ion monitoring. Operationally, the M-SPE method provided a simple means to isolate PAH on site at the wellhead, particularly for anoxic water samples. Acceptable recoveries, ranging from 56 to over 100 percent, were observed for lower molecular weight PAH (naphthalene to pyrene) using the M-SPE method. Recoveries using M-SPE were somewhat lower, but reproducible, for higher molecular weight PAH (chrysene to benzo[ghi]perylene), ranging from 18 to 56 percent. M-SPE provides the capability to collect and field isolate PAH from a sufficiently large number of samples to identify environmental chemical processes occurring at individual compound concentrations of 50 to 1,200 nanograms per liter. Using M-SPE, the potential for facilitated transport of PAH by in situ-derived dissolved organic carbon (DOC) was evaluated at the site. Plots comparing DOC and PAH concentrations indicate that PAH concentrations increase exponentially with linear increases in DOC concentrations

  2. Employing Ionomer Membrane Technology to Extract Water from Brine, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Paragon Space Development Corporation proposes the use of an microporous-ionomer membrane pair to improve the robustness and effectiveness of membrane-based water...

  3. Amniotic membrane extract ameliorates benzalkonium chloride-induced dry eye in a murine model.

    Science.gov (United States)

    Xiao, Xinye; Luo, Pingping; Zhao, Hui; Chen, Jingyao; He, Hui; Xu, Yuxue; Lin, Zhirong; Zhou, Yueping; Xu, Jianjiang; Liu, Zuguo

    2013-10-01

    Human amniotic membrane (AM) is avascular but contains various beneficial bioactive factors, its extract (AE) is also effective in treating many ocular surface disorders. In this study, we for the first time evaluated the therapeutic effects of AE on dry eye induced by benzalkonium chloride in a BALB/c mouse model. Topical application of AE (1.5 and 3 μg/eye/day) resulted in significantly longer tear break-up time on Day 3 and 6, lower fluorescein staining scores on Day 3, and lower inflammatory index on Day 6. AE reduced corneal epithelial K10 expression, inflammatory infiltration, and levels of TNF-α, IL-1β and IL-6 in BAC treated mice than that in the control mice. Moreover, decreased TUNEL positive cells in cornea and increased goblet cells in conjunctiva were also observed in AE treated corneas. Finally, AE induced more Ki-67 positive cells in corneal epithelium of dry eye mouse. Taken together, our data provide further support for BAC induced dry eye model as a valuable for dry eye study and suggest a great potential for AE as a therapeutic agent in the clinical treatment of dry eye. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. Recovery of salicylic acid from aqueous solution by solvent extraction and supported liquid membrane using TOMAC as carrier

    International Nuclear Information System (INIS)

    Kouki, Noura; Tayeb, Rafik; Dhahbi, Mahmoud

    2009-01-01

    Conventional sewage treatment plants do not fully degrade residues of pharmaceuticals, so that they are introduced into the aquatic environment. On this basis, the demand for the development of efficient systems for removing these compounds from water has assumed a great research interest. Membrane operations are increasingly employed in many industrial sectors as important alternative technologies to the classical processes of separation. Among membrane-based separation processes, the use of supported liquid membranes (SLMs) has received growing attention during recent years. In our work we had tried to recover a pharmaceutical product, salicylic acid (S.A), from an aqueous solution by solvent extraction and supported liquid membrane using an ionic liquid: the tri octylmethylammonium chloride (TOMAC) as carrier. Ionic liquids has been revealed as interesting clean alternatives to classical solvents and their use as a liquid phase results in the stabilization of the SLMs duo to their negligible vapour pressure, the possibility of minimising their solubility in the surrounding phases by adequate selection of the cation and anion, and the greater capillary force associated with their high viscosity. For this reason we had studied the influence of different parameters which could affect the efficiency of the transport: pH of the feed phase, the nature of the strippant, the concentration of the strippant, the nature of the support and the initial concentration of the salicylic acid in the feed phase. We had noticed that the pH of the feed solution had no effect of the percentage extraction and after 24 hours we can extract completely our solute. TOMAC seemed to be a good extractant but we found difficult to strip salicylic acid from the TOMAC phase and this could be related to the formation of water micro environments in the ionic liquid membrane.

  5. Facilitated transport of uranium(VI) across supported liquid membranes containing T2EHDGA as the carrier extractant.

    Science.gov (United States)

    Panja, S; Mohapatra, P K; Tripathi, S C; Manchanda, V K

    2011-04-15

    Facilitated transport of uranyl ion from nitric acid feed solutions was investigated across PTFE supported liquid membranes using N,N,N',N'-tetra-2-ethylhexyl-3-pentane-diamide (T2EHDGA) in n-dodecane as the carrier extractant containing 30% iso-decanol as the phase modifier. Solvent extraction studies indicated extraction of species of the type, UO(2)(NO(3))(2)·T2EHDGA. The distribution coefficients increased in the presence of NaNO(3) as compared to equivalent concentration of HNO(3) which was exactly the opposite of what was reported for Am(III)-TODGA extraction system. Supported liquid membrane studies indicated about 11h were required for quantitative transport of U(VI) from a feed of 3M HNO(3) using 0.2M T2EHDGA in n-dodecane containing 30% iso-decanol as the carrier extractant. Effect of various parameters such as feed acidity, T2EHDGA concentration, and nature of the strippant on the transport rate was investigated. The transport was found to be diffusion controlled in the membrane phase and the permeability coefficient was calculated to be (3.20 ± 0.13)× 10(-4)cm/s for the feed composition of 3M HNO(3), receiver phase composition of 0.01 M HNO(3) and membrane carrier phase of 0.2M T2EHDGA in n-dodecane containing 30% iso-decanol. The present results may be useful for the separation of U from lean solutions or radioactive wastes considered hazardous due to the presence of alpha-particle emitting radionuclides. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Extraction of Lead through Supported Liquid Membrane Using Triethanolamine/Cyclohexanone Carrier and Na2SO4 strippant

    Directory of Open Access Journals (Sweden)

    Gill R.

    2013-04-01

    Full Text Available Supported liquid membranes (SLM have proved to be effective not only for removing but also for recovery of heavy metals from waste water. This work includes the study of separation and transport of Pb+2 ions through liquid membrane based on triethanolamine (TEA in cyclohexanone supported in microporous polypropylene films. Therefore, this study aims to optimize the conditions for moving the Pb+2 ions against the concentration gradient, characterize the membrane by flux measurements, for their use in various industrial plants design to recover these ions. The effect of lead ion concentration, HNO3 in feed and TEA concentration in membrane has been studied. Optimized condition of transport of this metal ion is 1.0 M acid concentration in the feed phase and 0.1M Na2SO4 as the strippant when TEA concentration is 5.25 mol/dm3 in the membrane, as the rationale of this study is to optimize the condition for the movement of lead ions from feed phase to strip phase and to recover metal ions from any industrial effluent and finally to characterize the membrane by determining the mobility and permeability of the complexed heavy metal ion to extract their respective metal ions.

  7. Integrated photografted molecularly imprinted polymers with a cellulose acetate membrane for the extraction of melamine from dry milk before HPLC analysis.

    Science.gov (United States)

    Akbari-Adergani, Behrouz; Sadeghian, Gholam-Hossein; Alimohammadi, Alireza; Esfandiari, Zahra

    2017-03-01

    In this study, a new separation technique based on membrane extraction is described for the determination of melamine in dry milk. The water-compatible cellulose acetate membrane, which is photografted by melamine imprinted nanospheres, was prepared by placing the membrane into the polymerization solution containing methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as cross-linker, acetonitrile as porogen, and melamine as the template molecule. The characterization of the polymeric membrane was performed by Fourier transmission infrared spectroscopy and scanning electron microscopy. This integrated composite membrane was used as a solid-phase extraction medium for the extraction of melamine from dry milk samples. Various parameters affecting the extraction efficiency of the membrane were evaluated. The results showed higher binding capacity for melamine imprinted membranes in comparison with the nonimprinted membranes. High-performance liquid chromatography analysis showed that the extraction of melamine from dry milk by the photografted cellulose acetate membrane had a linear calibration curve in the range of 0.02-11.80 μg/mL with an excellent precision of 2.73%. The limit of detection and quantification of melamine was 0.007 and 0.020 μg/mL, respectively. The recoveries of melamine were in the range of 88.7-94.8%. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Sample clean-up, enrichment and determination of s-triazine herbicides from southern ethiopian lakes supported using liquid membrane extraction

    Directory of Open Access Journals (Sweden)

    Jan Åke Jönsson

    2000-06-01

    Full Text Available The liquid membrane extraction method has been employed for selectively extracting trace quantities of s-triazine herbicides in environmental waters collected from lakes Awassa, Chamo and Abbya, located in close proximity to the agricultural farms in Southern Ethiopia. In liquid membrane extraction, the uncharged triazine compounds from the flowing donor solution diffuse through a porous poly(tetrafluoroethylene (PTFE membrane, containing a water immiscible organic solvent. The s-triazine molecules are then irreversibly trapped in the stagnant acidic acceptor phase since they become protonated. Using both di-n-hexylether and n-undecane membrane solvents, s-traizine herbicides were extracted and low detection limits of about 1 ng/L have been obtained by extraction of three liters of sample solution spiked with 0.1 g/L of each triazine. Residues of atrazine and terbutryn ranging in concentration from 0.02 to 0.05 g/L have been successfully determined.

  9. Pseudo-biphasic extraction and liquid membrane transport of ionic solutes using micelle-based processes

    International Nuclear Information System (INIS)

    Tondre, Ch.

    1995-01-01

    Different aspects between micellar extraction and solvent extraction were discussed. One way of using micellar systems to perform metal ion extraction consists in solubilizing lipophilic complexing agents in the hydrophobic core of the micelles, similarly to their solubilization in the organic phase in classical biphasic extraction. Metal ions dissolved in the continuous phase will be complexed or not, depending on their affinity for the micelle-solubilized extractant, the microscopic micelle/water interface playing a part analogous to the macroscopic organic/water interface in biphasic extraction. The yields of extraction (after ultrafiltration of the micellar pseudo-phase) when parameters such as the extractant/metal ratio or the extractant hydrophobicity are changed, show similar trends as those reported in the case of solvent extraction, but only diluted solutions can be treated that way. 14 refs

  10. Regulation of membrane peptides by the Pseudomonas plasmid alk regulon.

    Science.gov (United States)

    Benson, S; Oppici, M; Shapiro, J; Fennewald, M

    1979-12-01

    Pseudomonas putida strains carrying the plasmid alk genes will grow on n-alkanes. Induced alk+ strains contain membrane activities for alkane hydroxylation and dehydrogenation of aliphatic primary alcohols. P. putida cytoplasmic and outer membranes can be separated by sucrose gradient centrifugation after disruption of cells by either mild detergent lysis or passage through a French press. Both the membrane component of alkane hydroxylase and membrane alcohol dehydrogenase fractionated with the cytoplasmic membrane. Induction of the alk regulon resulted in the appearance of at least three new plasmid-determined cytoplasmic membrane peptides of about 59,000 (59K), 47,000 (47K), and 40,000 (40K) daltons as well as the disappearance of a pair of chromosomally encoded outer membrane peptides of about 43,000 daltons. The 40K peptide is the membrane component of alkane hydroxylase and the product of the plasmid alkB gene because the alkB1029 mutation altered the properties of alkane hydroxylase in whole cells, reduced its thermal stability in cell extracts, and led to increased electrophoretic mobility of the inducible 40K peptide. These results are consistent with a model for vectorial oxidation of n-alkanes in the cytoplasmic membrane of P. putida.

  11. Development of a surfactant liquid membrane extraction process for the cleansing of industrial aqueous effluents containing metallic cation traces

    International Nuclear Information System (INIS)

    Rapaumbya Akaye, Guy-Roland

    1994-01-01

    The purpose of this work was to develop a process of surfactant liquid membrane extraction to purify industrial waste solution containing Cu(II), Fe(III), and Zn(II) (about 0,1 g/L). The extractant is the ammonium salt of Cyanex 306 and Aliquat 336. The first part of this work deals with the study of the liquid-liquid extraction of the metals. The efficiency of the extractant has been shown for the extraction of each metal alone and for Cu(II) and Zn(II) in the case of a mixture of the three metals. During this study we have observed that Fe(III) is reduced to Fe(II) (which is not extracted by the salt of Cyanex 301) in presence of Cu(II) and the quaternary ammonium salt (Aliquat 336). The optimisation of the experimental conditions for the discontinuous surfactant liquid membrane process led us to choose the following composition of the emulsion: 1,5 % of Cyanex 301 salt, 2,5 % of ECA 4360, dodecan. The internal phase is an aqueous solution containing 3,5 mol/L of NaOH and 0,5 mol/L tri-ethanolamin The residual concentration of Cu(II) and Zn(II) in the external phase is very low. In the case of iron, only 60 % are extracted because of the reduction phenomenon (10 % in liquid-liquid extraction). The realisation of the continuous process in pulsed column, after optimisation of hydrodynamics conditions, leads to similar results. In stationary conditions, we obtain a raffinate containing less than 0,5 mg/L of Cu(II) and Zn(II) and 36 mg/L of iron. The internal phase contains about 2 g/L of Cu(II) an Zn(II). We tried and minimize the reduction of Fe(III) in surfactant liquid membrane process. Less than 16 % of iron cannot be reduced. This leads to a purification of only 84 % In the basis of these results, processes of purification have been proposed for effluents of various composition. They enable to purify the effluent and besides to concentrate the pollutants about twenty times. (author) [fr

  12. Synthesis and functioning of the colicin E1 lysis protein: Comparison with the colicin A lysis protein

    International Nuclear Information System (INIS)

    Cavard, D.

    1991-01-01

    The colicin E1 lysis protein, CelA, was identified as a 3-kDa protein in induced cells of Escherichia coli K-12 carrying pColE1 by pulse-chase labeling with either [ 35 S]cysteine or [ 3 H]lysine. This 3-kDa protein was acylated, as shown by [2- 3 H]glycerol labeling, and seemed to correspond to the mature CelA protein. The rate of modification and processing of CelA was different from that observed for Cal, the colicin A lysis protein. In contrast to Cal, no intermediate form was detected for CelA, no signal peptide accumulated, and no modified precursor form was observed after globomycin treatment. Thus, the rate of synthesis would not be specific to lysis proteins. Solubilization in sodium dodecyl sulfate of the mature forms of both CelA and Cal varied similarly at the time of colicin release, indicating a change in lysis protein structure. This particular property would play a role in the mechanism of colicin export. The accumulation of the signal peptide seems to be a factor determining the toxicity of the lysis proteins since CelA provoked less cell damage than Cal. Quasi-lysis and killing due to CelA were higher in degP mutants than in wild-type cells. They were minimal in pldA mutants

  13. Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4.

    Science.gov (United States)

    Nishino, Kohei; Kushima, Misaki; Matsuo, Yuzy; Matsuo, Yasuhiro; Kawamukai, Makoto

    2015-01-01

    Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

  14. Cell Lysis in S. pombe ura4 Mutants Is Suppressed by Loss of Functional Pub1, Which Regulates the Uracil Transporter Fur4.

    Directory of Open Access Journals (Sweden)

    Kohei Nishino

    Full Text Available Schizosaccharomyces pombe Δura4 cells lyse when grown on YPD medium. A S. pombe non-essential gene deletion library was screened to determine suppressors of the lysis phenotype. Deletion of the pub1 gene, which encoded E3 ubiquitin ligase, strongly suppressed cell lysis in Δura4 cells. The Δpub1 cells displayed high sensitivity to 5-fluorouracil, a toxic analog of uracil, and this sensitivity was suppressed by deletion of fur4, which encoded a uracil transporter. Fur4 localized primarily to the Golgi apparatus and vacuoles in wild-type cells, but localization was predominantly at the plasma membrane in Δpub1 cells. Fur4 was necessary for the utilization of extracellular uracil, cytosine, or UMP. Uracil uptake activity increased in the Δpub1 strain in a Fur4-dependent manner. In addition, uracil starvation was critical for induction of cell lysis of Δura4 strains and uracil supplementation suppressed lysis. In summary, the increased uracil uptake ability of Δpub1 cells, where Fur4 was predominantly localized to the plasma membrane, resulted in suppression of cell lysis in the Δura4 background.

  15. Clotrimazole enhances lysis of human erythrocytes induced by t-BHP.

    Science.gov (United States)

    Lisovskaya, Irene L; Shcherbachenko, Irina M; Volkova, Rimma I; Ataullakhanov, Fazoil I

    2009-08-14

    Clotrimazole (CLT) is an antifungal and antimalarial agent also effective as a Gardos channel inhibitor. In addition, CLT possesses antitumor properties. Recent data provide evidence that CLT forms a complex with heme (hemin), which produces a more potent lytic effect than heme alone. This study addressed the effect of CLT on the lysis of normal human erythrocytes induced by tert-butyl hydroperoxide (t-BHP). For the first time, it was shown that 10 microM CLT significantly enhanced the lytic effect of t-BHP on erythrocytes in both Ca(2+)-containing and Ca(2+)-free media, suggesting that the effect is not related to Gardos channels. CLT did not affect the rate of free radical generation, the kinetics of GSH degradation, methemoglobin formation and TBARS generation; therefore, we concluded that CLT does not cause additional oxidative damage to erythrocytes treated with t-BHP. It is tempted to speculate that CLT enhances t-BHP-induced changes in erythrocyte volume and lysis largely by forming a complex with hemin released during hemoglobin oxidation in erythrocytes: the CLT-hemin complex destabilizes the cell membrane more potently than hemin alone. If so, the effect of CLT on cell membrane damage during free-radical oxidation may be used to increase the efficacy of antitumor therapy.

  16. Lysis of Gymnodinium breve by cultures of the green alga Nannochloris eucaryotum.

    Science.gov (United States)

    Pérez, E; Sawyers, W G; Martin, D F

    2001-01-01

    Laboratory cultures of Florida's red tide organism, Gymnodinium breve, were killed by the green alga Nannochloris eucaryotum. Studies involved organism-organism interaction as well as organism-cell-free culture (N. eucaryotum) interaction. Both studies demonstrated that N. eucaryotum adversely affected Florida's red tide organism. The lysis has been attributed to compounds called APONINs (apparent oceanic naturally occurring cytolins). N. eucaryotum crude APONIN was extracted from cell-free cultures, partially purified and fractionated. The fractions were bioassayed against G. breve, and 'fingerprints' of the deleterious fractions were obtained.

  17. An extractive membrane biofilm reactor as alternative technology for the treatment of methyl tert-butyl ether contaminated water.

    Science.gov (United States)

    Guisado, I M; Purswani, J; González-López, J; Pozo, C

    2016-09-01

    Among the strategies developed for contaminated groundwater bioremediation, those based on the use of bacteria adhering to inert supports and establishing biofilms have gained great importance in this field. Extractive membrane biofilm reactor (EMBFR) technology offers productive solutions for the removal of volatile and semi-volatile compounds. EMBFR technology is based on the use of extractive semipermeable membranes through which contaminants migrate to the biological compartment in which microorganisms with pollutant biotransformation and/or mineralization capacities can grow, forming an active biofilm on the membrane surface. The objective of this study was to assess the use of three bacterial strains (Paenibacillus sp. SH7 CECT 8558, Agrobacterium sp. MS2 CECT 8557, and Rhodococcus ruber EE6 CECT 8612), as inoculum in a lab-scale EMBFR running for 28 days under aerobic conditions to eliminate methyl tert-butyl ether (MTBE) from water samples. Three different hydraulic retention times (1, 6, and 12 h) were employed. MTBE degradation values were determined daily by a gas GC-MS technique, as well as suspended bacterial growth. The biofilm established by the bacterial strains on the semipermeable membrane was detected by Field-Emission Scanning Electron Microscopy (FESEM) at the end of each experiment. The acute toxicity of the treated effluents and biomedium was determined by Microtox © assay (EC 50 ).The results achieved from the MTBE degradation, biofilm formation, and toxicity analysis indicated that bacterial strains MS2 and EE6 were the best options as selective inoculum, although further research is needed, particularly with regard to their possible use as a mixed culture. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 32:1238-1245, 2016. © 2016 American Institute of Chemical Engineers.

  18. Monitoring of N-methyl carbamate pesticide residues in water using hollow fibre supported liquid membrane and solid phase extraction

    Science.gov (United States)

    Msagati, Titus A. M.; Mamba, Bhekie B.

    The aim of this work was to develop a method for the determination of N-methyl carbamates in water involving hollow fibre supported liquid membrane (HFSLM) and solid phase extraction (SPE) as sample preparation methods. Four N-methyl carbamate pesticides, aldicarb, carbaryl, carbofuran and methiocarb sulfoxide, were simultaneously extracted and analysed by a liquid chromatograph with a diode array detector (LC-UV/DAD) and a liquid chromatograph coupled to a ion trap quadrupole mass spectrometer (LC-ESI-MS). The high performance liquid chromatography (HPLC) separation of carabamate extracts was performed on a C18 column with water-acetonitrile as the mobile phase. The mass spectrometry analyses were carried out in the positive mode, operating under both the selected ion monitoring (SIM) and full scan modes. The solid phase recoveries of the extracts ranged between 8% and 98%, with aldicarb having the highest recoveries, followed by carbaryl, carbofuran and methiocarb had the lowest recovery. The HFSLM recovery ranged between 8% and 58% and the order of recovery was similar to the SPE trend. Factors controlling the efficiency of the HFSLM extraction such as sample pH, stripping phase pH, enrichment time, stirring speed as well as organic solvent used for entrapment of analytes, were optimised to achieve the highest enrichment factors.

  19. Alkaline-cell lysis through in-line static mixer reactor for the production of plasmid DNA for gene therapy.

    Science.gov (United States)

    Chamsart, Saethawat; Karnjanasorn, Tanyawat

    2007-02-15

    A state-of-the-art in-line static mixer reactor (ISMR) was invented to lyse E. coli cells and neutralize the cell lysate continuously and efficiently for the extraction of plasmid DNA. It comprised two connected static dynamic mixers, each 0.01 m in diameter and 0.9 m in length, one for lysis and one for neutralization. Cells were lysed using concentrated alkaline with 1% SDS and the lysate was neutralized at feed rates of cell suspension:lysis solution:neutralization solution of 125:250:125, 250:500:250, and 500:1,000:500 mL/min. Distances for the mixtures to reach color homogeneity were dependent on feed rates. The higher the feed rates the shorter the mixing distances and times. However, complete cell lysis and neutralization were independent of color homogeneity. Lysate viscosity and neutralized floc size decreased and floc density increased, as distances and feed rates increased. High plasmid yields were obtained from both lysis and neutralization at feed rate ratios of 125:250:125 and 250:500:250 mL/min within mixing distances or =0.6 m at all feed rates due to a longer exposure to strong alkali and shear flow. This invention showed excellent performance with scaleable potential for the commercial manufacture of plasmid DNA.

  20. Fully Automated Electro Membrane Extraction Autosampler for LC-MS Systems Allowing Soft Extractions for High-Throughput Applications

    DEFF Research Database (Denmark)

    Fuchs, David; Pedersen-Bjergaard, Stig; Jensen, Henrik

    2016-01-01

    was optimized for soft extraction of analytes and high sample throughput. Further, it was demonstrated that by flushing the EME-syringe with acidic wash buffer and reverting the applied electric potential, carry-over between samples can be reduced to below 1%. Performance of the system was characterized (RSD......, a complete analytical workflow of purification, separation, and analysis of sample could be achieved within only 5.5 min. With the developed system large sequences of samples could be analyzed in a completely automated manner. This high degree of automation makes the developed EME-autosampler a powerful tool...

  1. Novel diglycolamide functionalized calix[4]arenes for actinide extraction and supported liquid membrane studies: Part II. Role of substituents in the pendent arms and mass transfer modeling I

    NARCIS (Netherlands)

    Ansari, S.A.; Mohapatra, P.K.; Iqbal, M.; Kandwal, P.; Huskens, Jurriaan; Verboom, Willem

    2013-01-01

    Several calix[4]arene-functionalized diglycolamide (C4DGA) ligands were evaluated for the extraction as well as supported liquid membrane (SLM) transport of actinides and fission product elements from nitric acid feed solutions. The extraction efficiency of the C4DGA ligands for Am(III) was orders

  2. The Effects of Total Extract Ocimumbasilicumon VEGF Gene Expression Changes in Chick Embryo Chorioallantoic Membrane Angiogenesis

    Directory of Open Access Journals (Sweden)

    Fateme Niazi

    2017-11-01

    Conclusion: Both aqueous and alcoholic extracts of basil increased VEGF gene expression. The study showed an increase in the number and length of vessels. According to the increasing effects, basil aqueous and alcoholic extracts can affect the molecular processes of growth and dependent processes.

  3. Extraction of uranium(VI) by emulsion liquid membrane containing 5,8-diethyl-7-hydroxy-6-dodecanone oxime

    International Nuclear Information System (INIS)

    Akiba, Kenichi; Takahashi, Toshihiko; Kanno, Takuji

    1984-01-01

    Extraction of uranium(VI) by a liquid surfactant membrane has been studied. The stability of water-in-oil (w/o) emulsion dispersed in the continuous aqueous phase increased with an increase in surfactant concentrations and in the fraction of the organic phase in emulsion globules. Uranium(VI) in dilute acid solutions was extracted into (w/o) emulsions containing 5,8-diethyl-7-hydroxy-6-dodecanone oxime (LIX 63) as a mobile carrier and its concentration decreased according to [U]sub(t)=[U]sub(o)exp(-ksub(obsd)t). The apparent rate constants (ksub(obsd)) increased with an increase in carrier concentrations and in external pH values, while they were slightly dependent on the stripping acid concentrations. Uranium was transported and concentrated into the internal aqueous droplets. The final concentration of uranium in the external aqueous phase dropped to about 10 -3 of its initial value. (author)

  4. Membrane biofouling characterization: effects of sample preparation procedures on biofilm structure and the microbial community

    KAUST Repository

    Xue, Zheng

    2014-07-15

    Ensuring the quality and reproducibility of results from biofilm structure and microbial community analysis is essential to membrane biofouling studies. This study evaluated the impacts of three sample preparation factors (ie number of buffer rinses, storage time at 4°C, and DNA extraction method) on the downstream analysis of nitrifying biofilms grown on ultrafiltration membranes. Both rinse and storage affected biofilm structure, as suggested by their strong correlation with total biovolume, biofilm thickness, roughness and the spatial distribution of EPS. Significant variations in DNA yields and microbial community diversity were also observed among samples treated by different rinses, storage and DNA extraction methods. For the tested biofilms, two rinses, no storage and DNA extraction with both mechanical and chemical cell lysis from attached biofilm were the optimal sample preparation procedures for obtaining accurate information about biofilm structure, EPS distribution and the microbial community. © 2014 © 2014 Taylor & Francis.

  5. Extraction Socket Preservation Using Porcine-Derived Collagen Membrane Alone or Associated with Porcine-Derived Bone. Clinical Results of Randomized Controlled Study

    Directory of Open Access Journals (Sweden)

    Renzo Guarnieri

    2017-03-01

    Full Text Available Objectives: The aim of present randomized controlled clinical trial was to clinically evaluate hard tissue changes after extraction socket preservation procedures compared to natural spontaneous healing. Material and Methods: Thirty patients were enrolled in the present study and underwent single-tooth extraction in the premolar/molar areas. Ten sites were grafted with porcine-derived bone covered by collagen membrane, 10 covered by porcine-derived collagen membrane alone, and 10 underwent natural spontaneous healing. Vertical and horizontal bone changes after 3-month were evaluated at implant placement. Results: The vertical and horizontal bone changes at the extraction sockets treated with collagen membrane alone (vertical: -0.55 [SD 0.11] mm, and horizontal: -1.21 [SD 0.69] mm and collagen membrane plus porcine-derived bone (vertical: -0.37 [SD 0.7] mm, and horizontal: -0.91 [SD 0.53] mm were found significantly lower (P < 0.001, when compared to non-grafted sockets (vertical: -2.09 [SD 0.19] mm, and horizontal: -3.96 [SD 0.87] mm. In type 1 extraction sockets, in premolar sites, and in presence of vestibular bone thicknesses ≥ 1.5 mm, the use of collagen membrane alone revealed similar outcomes to those with additional graft material. Conclusions: At the re-entry surgery, extraction sockets grafted with porcine-derived bone and covered by collagen membrane, and extraction sockets covered by porcine-derived collagen membrane alone, showed significantly lower vertical and horizontal bone changes, compared to extraction sockets sites underwent natural spontaneous healing. However, a complete prevention of remodelling is not achievable, irrespective of the technique used.

  6. Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Esteve-Turrillas, Francesc A. [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain); Pastor, Agustin [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)]. E-mail: agustin.pastor@uv.es; Guardia, Miguel de la [Analytical Chemistry Department, University of Valencia, Edifici Jeroni Munoz, 50th Dr. Moliner, 46100 Burjassot, Valencia (Spain)

    2006-02-23

    A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C{sub 18}. Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, {lambda}-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 {+-} 8 to 103 {+-} 7% for microwave-assisted extraction, versus 54 {+-} 4 to 104 {+-} 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 {mu}g/SPMD, were found in indoor air after 2 h of a standard application.

  7. Selective Interactions of Valeriana officinalis Extracts and Valerenic Acid with [3H]Glutamate Binding to Rat Synaptic Membranes

    Science.gov (United States)

    Del Valle-Mojica, Lisa M.; Ayala-Marín, Yoshira M.; Ortiz-Sanchez, Carmen M.; Torres-Hernández, Bianca A.; Abdalla-Mukhaimer, Safa; Ortiz, José G.

    2011-01-01

    Although GABA neurotransmission has been suggested as a mechanism for Valeriana officinalis effects, CNS depression can also be evoked by inhibition of ionotropic (iGluR) and metabotropic glutamate receptors (mGluR). In this study, we examined if aqueous valerian extract interacted with glutamatergic receptors. Freshly prepared aqueous valerian extract was incubated with rat cortical synaptic membranes in presence of 20 nM [3H]Glutamate. Aqueous valerian extract increased [3H]Glutamate binding from 1 × 10−7 to 1 × 10−3 mg/mL. In the presence of (2S,1′S,2′S)-2-(Carboxycyclopropyl)glycine (LCCG-I) and (2S,2′R,3′R)-2-(2′,3′-Dicarboxycyclopropyl)glycine (DCG-IV), Group II mGluR agents, valerian extract markedly decreased [3H]Glutamate binding, while (2S)-2-amino-3-(3,5-dioxo-1,2,4-oxadiazolidin-2-yl) propanoic acid) (quisqualic acid, QA), Group I mGluR agonist, increased [3H]Glutamate binding. At 0.05 mg/mL aqueous valerian extract specifically interacted with kainic acid NMDA and AMPA receptors. Valerenic acid, a marker compound for Valeriana officinalis, increased the [3H]Glutamate binding after 1.6 × 10−2 mg/mL, and at 0.008 mg/mL it interacted only with QA (Group I mGluR). The selective interactions of valerian extract and valerenic acid with Group I and Group II mGluR may represent an alternative explanation for the anxiolytic properties of this plant. PMID:21584239

  8. Microwave-assisted extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs) used to indoor air monitoring

    International Nuclear Information System (INIS)

    Esteve-Turrillas, Francesc A.; Pastor, Agustin; Guardia, Miguel de la

    2006-01-01

    A rapid and environmentally friendly methodology was developed for the extraction of pyrethroid insecticides from semi permeable membrane devices (SPMDs), in which they were preconcentrated in gas phase. The method was based on gas chromatography mass-mass spectrometry determination after a microwave-assisted extraction, in front of the widely employed dialysis method. SPMDs were extracted twice with 30 mL hexane:acetone, irradiated with 250 W power output, until 90 deg. C in 10 min, this temperature being held for another 10 min. Clean-up of the extracts was performed by acetonitrile-hexane partitioning and solid-phase extraction (SPE) with a combined cartridge of 2 g basic-alumina, deactivated with 5% water, and 500 mg C 18 . Pyrethroids investigated were Allethrin, Prallethrin, Tetramethrin, Bifenthrin, Phenothrin, λ-Cyhalothrin, Permethrin, Cyfluthrin, Cypermethrin, Flucythrinate, Esfenvalerate, Fluvalinate and Deltamethrin. The main pyrethroid synergist compound, Pyperonyl Butoxide, was also studied. Limit of detection values ranging from 0.3 to 0.9 ng/SPMD and repeatability data, as relative standard deviation, from 2.9 to 9.4%, were achieved. Pyrethroid recoveries, for spiked SPMDs, with 100 ng of each one of the pyrethroids evaluated, were from 61 ± 8 to 103 ± 7% for microwave-assisted extraction, versus 54 ± 4 to 104 ± 3% for dialysis reference method. Substantial reduction of solvent consumed (from 400 to 60 mL) and analysis time (from 48 to 1 h) was achieved by using the developed procedure. High concentration levels of pyrethroid compounds, from 0.14 to 7.3 μg/SPMD, were found in indoor air after 2 h of a standard application

  9. Perforin enhances the granulysin-induced lysis of Listeria innocua in human dendritic cells

    Directory of Open Access Journals (Sweden)

    Wagner Carsten A

    2007-08-01

    Full Text Available Abstract Background Cytotoxic T lymphocytes (CTL and natural killer (NK cells play an essential role in the host defence against intracellular pathogens such as Listeria, and Mycobacteria. The key mediator of bacteria-directed cytotoxicity is granulysin, a 9 kDa protein stored in cytolytic granules together with perforin and granzymes. Granulysin binds to cell membranes and is subsequently taken up via a lipid raft-associated mechanism. In dendritic cells (DC granulysin is further transferred via early endosomes to L. innocua-containing phagosomes were bacteriolysis is induced. In the present study we analysed the role of perforin in granulysin-induced intracellular bacteriolysis in DC. Results We found granulysin-induced lysis of intracellular Listeria significantly increased when perforin was simultaneously present. In pulse-chase experiments enhanced bacteriolysis was observed when perforin was added up to 25 minutes after loading the cells with granulysin demonstrating no ultimate need for simultaneous uptake of granulysin and perforin. The perforin concentration sufficient to enhance granulysin-induced intracellular bacteriolysis did not cause permanent membrane pores in Listeria-challenged DC as shown by dye exclusion test and LDH release. This was in contrast to non challenged DC that were more susceptible to perforin lysis. For Listeria-challenged DC, there was clear evidence for an Ca2+ influx in response to sublytic perforin demonstrating a short-lived change in the plasma membrane permeability. Perforin treatment did not affect granulysin binding, initial uptake or intracellular trafficking to early endosomes. However, enhanced colocalization of granulysin with listerial DNA in presence of perforin was found by confocal laser scanning microscopy. Conclusion The results provide evidence that perforin increases granulysin-mediated killing of intracellular Listeria by enhanced phagosome-endosome fusion triggered by a transient Ca2+ flux.

  10. Perforin enhances the granulysin-induced lysis of Listeria innocua in human dendritic cells.

    Science.gov (United States)

    Walch, Michael; Latinovic-Golic, Sonja; Velic, Ana; Sundstrom, Hanna; Dumrese, Claudia; Wagner, Carsten A; Groscurth, Peter; Ziegler, Urs

    2007-08-16

    Cytotoxic T lymphocytes (CTL) and natural killer (NK) cells play an essential role in the host defence against intracellular pathogens such as Listeria, and Mycobacteria. The key mediator of bacteria-directed cytotoxicity is granulysin, a 9 kDa protein stored in cytolytic granules together with perforin and granzymes. Granulysin binds to cell membranes and is subsequently taken up via a lipid raft-associated mechanism. In dendritic cells (DC) granulysin is further transferred via early endosomes to L. innocua-containing phagosomes were bacteriolysis is induced. In the present study we analysed the role of perforin in granulysin-induced intracellular bacteriolysis in DC. We found granulysin-induced lysis of intracellular Listeria significantly increased when perforin was simultaneously present. In pulse-chase experiments enhanced bacteriolysis was observed when perforin was added up to 25 minutes after loading the cells with granulysin demonstrating no ultimate need for simultaneous uptake of granulysin and perforin. The perforin concentration sufficient to enhance granulysin-induced intracellular bacteriolysis did not cause permanent membrane pores in Listeria-challenged DC as shown by dye exclusion test and LDH release. This was in contrast to non challenged DC that were more susceptible to perforin lysis. For Listeria-challenged DC, there was clear evidence for an Ca2+ influx in response to sublytic perforin demonstrating a short-lived change in the plasma membrane permeability. Perforin treatment did not affect granulysin binding, initial uptake or intracellular trafficking to early endosomes. However, enhanced colocalization of granulysin with listerial DNA in presence of perforin was found by confocal laser scanning microscopy. The results provide evidence that perforin increases granulysin-mediated killing of intracellular Listeria by enhanced phagosome-endosome fusion triggered by a transient Ca2+ flux.

  11. Dried blood spots and parallel artificial liquid membrane extraction-A simple combination of microsampling and microextraction.

    Science.gov (United States)

    Ask, Kristine Skoglund; Øiestad, Elisabeth Leere; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2018-06-07

    In this paper, parallel artificial liquid membrane extraction (PALME) was used for the first time to clean-up dried blood spots (DBS) prior to ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Fundamental studies exploring amongst others desorption from the DBS in alkaline or acidic aqueous conditions, total extraction time and absolute recoveries were executed. Desorption and PALME were performed using a set of two 96-well plates, one of them housing the sample and the other comprising the supported liquid membrane (SLM) and the acceptor solution. In one procedure, amitriptyline and quetiapine (basic model analytes) were desorbed from the DBS using 250 μL of 10 mM sodium hydroxide solution (aqueous), and subsequently extracted through the SLM consisting of 4 μL of 1% trioctylamine in dodecyl acetate, and further into an acceptor solution consisting of 50 μL of 20 mM formic acid. In a second procedure, ketoprofen, fenoprofen, flurbiprofen, and ibuprofen (acidic model analytes) were desorbed from the DBS into 20 mM formic acid, extracted through an SLM with dihexyl ether, and further into an acceptor solution of 25 mM ammonia. Within 60 min of PALME, both basic and acidic model analytes were effectively desorbed from the DBS and extracted into the acceptor solution, which was injected directly into the analytical instrument. Recoveries between 63 and 85% for the six model analytes were obtained. PALME provided excellent clean-up from the DBS samples, and acceptor solutions were free from phospholipids. Linearity was obtained with r 2  > 0.99 for five of the six analytes. Accuracy, precision and UHPLC-MS/MS matrix effects were in accordance with the European Medicines Agency (EMA) guideline. Based on these experiments, PALME shows great potential for future processing of DBS in a short and simple way, and with the presented setup, up to 96 DBS can be processed within a total extraction time of 60

  12. Inhibition of pneumococcal autolysis in lysis-centrifugation blood culture.

    OpenAIRE

    Lehtonen, O P

    1986-01-01

    The recovery of Streptococcus pneumoniae from the Isolator lysis-centrifugation blood culture has been low in many studies. The poor survival of pneumococci was not due to toxicity of the Isolator medium but to autolysis before plating. This autolysis was completely inhibited by adding 10 mM phosphorylcholine to the Isolator medium.

  13. Management of Pediatric Tumor Lysis Syndrome | Tazi | Arab ...

    African Journals Online (AJOL)

    Typical clinical sequelae include gastrointestinal disturbances, neuromuscular effects, cardiovascular complications, acute renal failure and death. Tumor lysis syndrome can also compromise the efficacy or administration of curative therapies. Available evidence suggests that the incidence of clinical TLS is approximately ...

  14. A novel toolbox for E. coli lysis monitoring.

    Science.gov (United States)

    Rajamanickam, Vignesh; Wurm, David; Slouka, Christoph; Herwig, Christoph; Spadiut, Oliver

    2017-01-01

    The bacterium Escherichia coli is a well-studied recombinant host organism with a plethora of applications in biotechnology. Highly valuable biopharmaceuticals, such as antibody fragments and growth factors, are currently being produced in E. coli. However, the high metabolic burden during recombinant protein production can lead to cell death, consequent lysis, and undesired product loss. Thus, fast and precise analyzers to monitor E. coli bioprocesses and to retrieve key process information, such as the optimal time point of harvest, are needed. However, such reliable monitoring tools are still scarce to date. In this study, we cultivated an E. coli strain producing a recombinant single-chain antibody fragment in the cytoplasm. In bioreactor cultivations, we purposely triggered cell lysis by pH ramps. We developed a novel toolbox using UV chromatograms as fingerprints and chemometric techniques to monitor these lysis events and used flow cytometry (FCM) as reference method to quantify viability offline. Summarizing, we were able to show that a novel toolbox comprising HPLC chromatogram fingerprinting and data science tools allowed the identification of E. coli lysis in a fast and reliable manner. We are convinced that this toolbox will not only facilitate E. coli bioprocess monitoring but will also allow enhanced process control in the future.

  15. The lysis cassette of bacteriophage ϕKMV encodes a signal-arrest-release endolysin and a pinholin.

    Science.gov (United States)

    Briers, Yves; Peeters, Liesbet M; Volckaert, Guido; Lavigne, Rob

    2011-01-01

    The lysis cassette of Pseudomonas aeruginosa phage ϕKMV encodes a holin, endolysin, Rz and Rz1 in the canonical order. It has a tight organization with a high degree of overlapping genes and is highly conserved (between 96 and 100% identity at the protein level) among several other members of the "phiKMV-like viruses." The endolysin KMV45 exhibits characteristics as expected for a signal-arrest-release (SAR) endolysin, whereas the holin KMV44 is a typical pinholin. KMV45 is initially secreted as an inactive, membrane-anchored endolysin, which is subsequently released by membrane depolarization driven by the pinholin KMV44. The SAR domain of KMV45 is necessary for its full enzymatic activity, suggesting a refolding of the catalytic cleft upon release from the membrane. The physical proximity of the catalytic glutamic acid residue close to SAR domain suggests an alternative activation mechanism compared to the SAR endolysin of phages P1, ERA103 and 21. Expression of KMV44 leads to a quick cell lysis when paired with SAR endolysin KMV45, but not with the cytoplasmic phage λ endolysin, indicating the membrane depolarizing function of KMV44 rather than the large hole-making function characteristic of classical holins.

  16. Bacterial Infochemicals are Drivers of Algal Lysis

    Science.gov (United States)

    Whalen, K.; Deering, R.; Rowley, D. C.; El Gamal, A.; Schorn, M.; Moore, B. S.; Johnson, M. D.; Mincer, T. J.; Harvey, E.

    2016-02-01

    Processing of organic matter by bacteria forces oceanic biogeochemical cycles, food web structure and ultimately environmental stoichiometry. A newly emerging picture of the microbial loop suggests that bacteria are not merely passive recipients of dissolved organic matter (DOM) from phytoplankton exudate. Rather, heterotrophic bacteria can mediate the flow of DOM by actively producing soluble algicidal compounds. However, deciphering those chemical signals that determine these interactions has remained a challenge. Here, we report the isolation of 2-heptyl-4-quinolone (HHQ), released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria isolated from plastic debris in the North Atlantic. Both 2-heptyl-3-hydroxy-4-quinolone and its immediate precursor, HHQ are known to function as antibiotics and quorum sensing signaling molecules with crucial roles in virulence, and apoptosis in eukaryotic cells (e.g. fungi and mammalian cells). Our ecologically-relevant screening of live cells and filtrate from P. piscicida cultures caused a significant decrease in the growth rate of the bloom-forming coccolithophore, Emiliania huxleyi. Bioassay-guided fraction of P. piscicida extracellular crude extracts identified HHQ, which induced mortality in three strains of E. huxleyi with an IC50 in the nanomolar range. In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures (IC50 > 10 micromolar), but were susceptible to extracts of P. piscicida, indicating this bacterium may produce a cocktail of algicidal compounds specific to different phytoplankton guilds. The ability of HHQ to influence phytoplankton growth suggests that alkylquinolone-signaling molecules play a fundamental role in interkingdom interactions, ultimately influencing shifts in phytoplankton population dynamics. This study implicates a new role for HHQ beyond its importance in quorum sensing.

  17. Soil pretreatment and fast cell lysis for direct polymerase chain reaction from forest soils for terminal restriction fragment length polymorphism analysis of fungal communities

    Science.gov (United States)

    Fei Cheng; Lin Hou; Keith Woeste; Zhengchun Shang; Xiaobang Peng; Peng Zhao; Shuoxin Zhang

    2016-01-01

    Humic substances in soil DNA samples can influence the assessment of microbial diversity and community composition. Using multiple steps during or after cell lysis adds expenses, is time-consuming, and causes DNA loss. A pretreatment of soil samples and a single step DNA extraction may improve experimental results. In order to optimize a protocol for obtaining high...

  18. Salt removal from microliter sample volumes by multiple phase microelectromembrane extractions across free liquid membranes

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel

    2017-01-01

    Roč. 89, č. 16 (2017), s. 8476-8483 ISSN 0003-2700 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : desalting * microelectromembrane extraction * electrospray ionization-mass spectrometry Subject RIV: CB - Analytical Chemistry , Separation OBOR OECD: Analytical chemistry Impact factor: 6.320, year: 2016

  19. Salt removal from microliter sample volumes by multiple phase microelectromembrane extractions across free liquid membranes

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel

    2017-01-01

    Roč. 89, č. 16 (2017), s. 8476-8483 ISSN 0003-2700 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : desalting * microelectromembrane extraction * electrospray ionization-mass spectrometry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 6.320, year: 2016

  20. EXTRACTION CHARACTERISTICS OF THE CATION OF ALKYLDIMETHYLBENZYLAMMONIUM CHLORIDE AT THE PHASE BOUNDARY WATER-MEMBRANE SOLVENT

    Directory of Open Access Journals (Sweden)

    O. V. Luganska

    2015-06-01

    Full Text Available The extraction coefficients of the cation of alkyldimethylbenzylammonium chloride at the phase boundary water-tricresylphosphate, water-dioctylphthalate, water-dibutylphtalate have been determined by the potentiometric titration of the aqueous phase with a silver electrode. The correctness of the obtained results has been proved by the titrimetric method with visual fixation of the equivalence point using methylene blue indicator.

  1. Electromembrane extraction of peptides - fundamental studies on the supported liquid membrane

    DEFF Research Database (Denmark)

    Seip, Knut Fredrik; Stigsson, Jeanette; Gjelstad, Astrid

    2011-01-01

    L) was after extraction analyzed directly, or with some dilution, on CE or HPLC. This article has identified mono- or di-substituted phosphate groups as the prominent group of carrier molecules needed to obtain acceptable recoveries. For the organic solvents, primary alcohols and ketones have shown promise...

  2. Application of Doehlert experimental design in the optimization of experimental variables for the Pseudozyma sp. (CCMB 306 and Pseudozyma sp. (CCMB 300 cell lysis

    Directory of Open Access Journals (Sweden)

    Amanda Reges de Sena

    2012-12-01

    Full Text Available This study aimed to verify the influence of pH and temperature on the lysis of yeast using experimental design. In this study, the enzymatic extract containing β-1,3-glucanase and chitinase, obtained from the micro-organism Moniliophthora perniciosa, was used. The experiment showed that the best conditions for lysis of Pseudozyma sp. (CCMB 306 and Pseudozyma sp. (CCMB 300 by lytic enzyme were pH 4.9 at 37 ºC and pH 3.9 at 26.7 ºC, respectively. The lytic enzyme may be used for obtaining various biotechnology products from yeast.

  3. Simultaneous AuIII Extraction and In Situ Formation of Polymeric Membrane-Supported Au Nanoparticles: A Sustainable Process with Application in Catalysis.

    Science.gov (United States)

    Mora-Tamez, Lucía; Esquivel-Peña, Vicente; Ocampo, Ana L; Rodríguez de San Miguel, Eduardo; Grande, Daniel; de Gyves, Josefina

    2017-04-10

    A polymeric membrane-supported catalyst with immobilized gold nanoparticles (AuNPs) was prepared through the extraction and in situ reduction of Au III salts in a one-step strategy. Polymeric inclusion membranes (PIMs) and polymeric nanoporous membranes (PNMs) were tested as different membrane-support systems. Transport experiments indicated that PIMs composed of cellulose triacetate, 2-nitrophenyloctyl ether, and an aliphatic tertiary amine (Adogen 364 or Alamine 336) were the most efficient supports for Au III extraction. The simultaneous extraction and reduction processes were proven to be the result of a synergic phenomenon in which all the membrane components were involved. Scanning electron microscopy characterization of cross-sectional samples suggested a distribution of AuNPs throughout the membrane. Transmission electron microscopy characterization of the AuNPs indicated average particle sizes of 36.7 and 2.9 nm for the PIMs and PNMs, respectively. AuNPs supported on PIMs allowed for >95.4 % reduction of a 0.05 mmol L -1 4-nitrophenol aqueous solution with 10 mmol L -1 NaBH 4 solution within 25 min. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Comparative, randomized, double-blind clinical study of alveolar ridge preservation using an extracellular matrix-based dental resorbable membrane in the extraction socket.

    Science.gov (United States)

    Chang, Hyeyoon; Kim, Sulhee; Hwang, Jin Wook; Kim, Sungtae; Koo, Ki-Tae; Kim, Tae-Il; Seol, Yang-Jo; Lee, Yong-Moo; Ku, Young; Lee, Jong-Ho; Rhyu, In-Chul

    2017-06-01

    The aim of this study was to radiographically and clinically compare the effect of extracellular matrix (ECM) membranes on dimensional alterations following a ridge preservation procedure. One of 2 different ECM membranes was applied during a ridge preservation procedure. A widely used ECM membrane (WEM; Bio-Gide, Geistlich Biomaterials, Wolhusen, Switzerland) was applied in the treatment group and a newly developed ECM membrane (NEM; Lyso-Gide, Oscotec Inc., Seongnam, Korea) was applied in the control group. Cone-beam computed tomography (CBCT) scans and alginate impressions were obtained 1 week and 6 months after the ridge preservation procedure. Results were analyzed using the independent t -test and the nonparametric Mann-Whitney U test. There were no significant differences between the ECM membranes in the changes in the dimension, width, and height of the extraction socket or the quantity of bone tissue. The NEM showed comparable clinical and radiographic results to the WEM following the ridge preservation procedure.

  5. Real Time Extraction Kinetics of Electro Membrane Extraction Verified by Comparing Drug Metabolism Profiles Obtained from a Flow-Flow Electro Membrane Extraction-Mass Spectrometry System with LC-MS.

    Science.gov (United States)

    Fuchs, David; Jensen, Henrik; Pedersen-Bjergaard, Stig; Gabel-Jensen, Charlotte; Hansen, Steen Honoré; Petersen, Nickolaj Jacob

    2015-06-02

    A simple to construct and operate, "dip-in" electromembrane extraction (EME) probe directly coupled to electrospray ionization-mass spectrometry (ESI-MS) for rapid extraction and real time analysis of various analytes was developed. The setup demonstrated that EME-MS can be used as a viable alternative to conventional protein precipitation followed by liquid chromatography-mass spectrometry (LC-MS) for studying drug metabolism. Comparison of EME-MS with LC-MS for drug metabolism analysis demonstrated for the first time that real time extraction of analytes by EME is possible. Metabolism kinetics were investigated for three different drugs: amitriptyline, promethazine, and methadone. By comparing the EME-MS extraction profiles of the drug substances and formed drug metabolites with the metabolism profiles obtained by conventional protein precipitation followed by LC-MS good correlation was obtained with only very limited time delay in the extraction. The results indicate that, by tuning the electromembrane properties, for example, by optimizing the extraction voltage, extremely fast extraction kinetics can be obtained. A metabolic profile could be generated while the drug was metabolized offering a significant time saving as compared to conventional LC-MS where laborious protein precipitation or other sample pretreatments are required before analysis. This makes the developed EME-MS setup a highly promising sample preparation method for various kinds of applications where fast and real-time analysis of analytes is of interest.

  6. Membrane extraction with sorbent interface-gas chromatography as an effective and fast means for continuous monitoring of thermal degradation products of polyacrylonitrile.

    Science.gov (United States)

    Kaykhaii, Massoud; Sarafraz-Yazdi, Ali; Chamsaz, Mahmood; Pawliszyn, Janusz

    2002-07-01

    A novel sample preparation technique, membrane extraction with a sorbent interface (MESI) has been optimized and used for continuous monitoring thermal degradation products in polyacrylonitrile (PAN) polymer headspace at different temperatures, followed by gas chromatography-mass spectrometry (GC-MS). MESI with a flat sheet poly(dimethyl siloxane)-polycarbonate (PDMS-PC) membrane and Tenax trap was used. The system is very simple, fast and reliable and allowed us to extract, enrich and continuously monitor major volatile compounds released from the polymer at different temperatures. The volatile and semi-volatile gaseous degradation products were identified. Sensitivity of the method depends on the length of time for trapping.

  7. High-throughput analysis of drugs in biological fluids by desorption electrospray ionization mass spectrometry coupled with thin liquid membrane extraction

    DEFF Research Database (Denmark)

    Rosting, Cecilie; Pedersen-Bjergaard, Stig; Hansen, Steen Honore'

    2013-01-01

    Biological fluids such as urine, saliva and whole blood were analyzed for contents of drugs by a new combination of desorption electrospray ionization mass spectrometry (DESI-MS) and thin liquid membrane extraction (TLME). Analytes from the sample were extracted into a thin liquid membrane...... into the method, methadone was detected in urine in full-scan mode with an LOD of 4 ng mL(-1), while amitriptyline, nortriptyline and pethidine showed LODs of 17 ng mL(-1). Quantification was possible for several basic drugs using one common internal standard, providing relative accuracies in the range of 10...

  8. Electromembrane extraction of polar basic drugs from plasma with pure bis(2-ethylhexyl) phosphite as supported liquid membrane

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Seip, Knut Fredrik; Gjelstad, Astrid

    2016-01-01

    Electromembrane extraction (EME) of polar basic drugs from human plasma was investigated for the first time using pure bis(2-ethylhexyl) phosphite (DEHPi) as the supported liquid membrane (SLM). The polar basic drugs metaraminol, benzamidine, sotalol, phenylpropanolamine, ephedrine...... were analyzed by high-performance liquid chromatography-ultraviolet detection (HPLC-UV). In contrast to other SLMs reported for polar basic drugs in the literature, the SLM of DEHPi was highly stable in contact with plasma, and the system-current across the SLM was easily kept below 50 μA. Thus......, electrolysis in the sample and acceptor solution was kept at an acceptable level with no detrimental consequences. For the polar model analytes, representing a log P range from -0.40 to 1.32, recoveries in the range 25-91% were obtained from human plasma. Strong hydrogen bonding and dipole interactions were...

  9. The Effect of Stachys Lavandulifolia Alcoholic Extract on Angiogenesis in Chorioallantoic Membrane of Ross Chicken Embryo

    Directory of Open Access Journals (Sweden)

    F Attarian

    2016-02-01

    sham-exposed groups did not show any significant differences. Length and weight mean of embryos and vessels length in all treatment groups demonstrated a significant difference compared to the sham group, Moreover, mean of vessel number did not reveal any significant differences in dose of 50. Conclusion: As the study findings indicated, the effect of this extract is dose dependet, so as it demonstrates pro angiogenesis in low doses and anti-angiogenesis effect in high doses.

  10. Real Time Extraction Kinetics of Electro Membrane Extraction Verified by Comparing Drug Metabolism Profiles Obtained from a Flow-Flow Electro Membrane Extraction-Mass Spectrometry System with LC-MS

    DEFF Research Database (Denmark)

    Fuchs, David; Jensen, Henrik; Pedersen-Bjergaard, Stig

    2015-01-01

    A simple to construct and operate, "dip-in" electromembrane extraction (EME) probe directly coupled to electrospray ionization-mass spectrometry (ESI-MS) for rapid extraction and real time analysis of various analytes was developed. The setup demonstrated that EME-MS can be used as a viable...... alternative to conventional protein precipitation followed by liquid chromatography-mass spectrometry (LC-MS) for studying drug metabolism. Comparison of EME-MS with LC-MS for drug metabolism analysis demonstrated for the first time that real time extraction of analytes by EME is possible. Metabolism kinetics...... were investigated for three different drugs: amitriptyline, promethazine, and methadone. By comparing the EME-MS extraction profiles of the drug substances and formed drug metabolites with the metabolism profiles obtained by conventional protein precipitation followed by LC-MS good correlation...

  11. Screening of plants acting against Heterometrus laoticus scorpion venom activity on fibroblast cell lysis.

    Science.gov (United States)

    Uawonggul, Nunthawun; Chaveerach, Arunrat; Thammasirirak, Sompong; Arkaravichien, Tarinee; Chuachan, Chattong; Daduang, Sakda

    2006-01-16

    The aqueous extracts of 64 plant species, listed as animal- or insect-bite antidotes in old Thai drug recipes were screened for their activity against fibroblast cell lysis after Heterometrus laoticus scorpion venom treatment. The venom was preincubated with plant extract for 30 min and furthered treated to confluent fibroblast cells for 30 min. More than 40% efficiency (test/control) was obtained from cell treatment with venom preincubated with extracts of Andrographis paniculata Nees (Acanthaceae), Barringtonia acutangula (L.) Gaertn. (Lecythidaceae), Calamus sp. (Palmae), Clinacanthus nutans Lindau (Acanthaceae), Euphorbia neriifolia L. (Euphorbiaceae), Ipomoea aquatica Forssk (Convolvulaceae), Mesua ferrea L. (Guttiferae), Passiflora laurifolia L. (Passifloraceae), Plectranthus amboinicus (Lour.) Spreng. (Labiatae), Ricinus communis L. (Euphorbiaceae), Rumex sp. (Polygonaceae) and Sapindus rarak DC. (Sapindaceae), indicating that they had a tendency to be scorpion venom antidotes. However, only Andrographis paniculata and Barringtonia acutangula extracts provided around 50% viable cells from extract treatments without venom preincubation. These two plant extracts are expected to be scorpion venom antidotes with low cytotoxicity.

  12. Spontaneous Tumour Lysis Syndrome in a Multiple Myeloma

    Directory of Open Access Journals (Sweden)

    Can Huzmeli

    2016-01-01

    Full Text Available The tumor lysis syndrome (TLS is a collection of metabolic abnormalities that occur in consequence of the release of intracellular contents following lysis of tumor cells. TLS occurs spontaneously or after chemotherapy. Spontaneous TLS is uncommon occurrence in multiple myeloma (MM. We define a case of a 70-year-old woman patient who was found to have MM with spontaneous TLS, following a compression fracture of the T-12 vertebrae. While serum uric acid and phosphorous levels were high, low calcium levels were identified. There were also acute kidney injury and metabolic acidosis. Upon the diagnosis of TLS, she was treated with hydration, allopurinol, sodium bicarbonate, and calcium gluconate. The improvement of her laboratory data was observed. We submitted this case in order to draw attention to the presentation of MM with spontaneous TLS.

  13. Extraction of Gold(III) from Hydrochloric Acid Solutions with a PVC-based Polymer Inclusion Membrane (PIM) Containing Cyphos® IL 104

    Science.gov (United States)

    Bonggotgetsakul, Ya Ya Nutchapurida; Cattrall, Robert W.; Kolev, Spas D.

    2015-01-01

    Abstract: Poly(vinyl chloride) (PVC) based polymer inclusion membranes (PIMs), with different concentrations of Cyphos® IL 104 as the membrane extractant/carrier, were studied for their ability to extract Au(III) from hydrochloric acid solutions. Some of the PIMs also contained one of the following plasticizers or modifiers: 2-nitrophenyloctyl ether, dioctylphthalate, 1-dodecanol, 1-tetradecanol, or tri(2-ethylhexyl) phosphate. The best performance, in terms of extraction rate and amount of Au(III) extracted, was exhibited by a PIM consisting of 25 wt% Cyphos® IL 104, 5 wt% 1-dodecanol, and 70 wt% PVC. An almost complete back-extraction of the Au(III) extracted from this membrane was achieved by using a 0.10 mol L−1 Na2SO3 receiver solution at pH 8. The stoichiometry of the extracted Au(III)/Cyphos® IL 104 adduct was determined as [P]+ [AuCl4]− H+ [PO2]− where [P]+ and [PO2]− represent trihexyl(tetradecyl) phosphonium and bis(2,4,4-trimethylpentyl) phosphinate ions, respectively. Back-extraction of Au(III) is suggested to occur by reduction of Au(III) to Au(I), with the formation of the species [Au(SO3)2]3− in the aqueous receiver solution. Loss of 1-dodecanol from the newly developed PIM to the aqueous solutions in contact with it was observed, which indicated that this membrane was suitable for single use in the efficient recovery of Au(III) from hydrochloric acid solutions of electronic scrap or recycled jewelry. PMID:26670259

  14. Extraction of Gold(III) from Hydrochloric Acid Solutions with a PVC-based Polymer Inclusion Membrane (PIM) Containing Cyphos(®) IL 104.

    Science.gov (United States)

    Bonggotgetsakul, Ya Ya Nutchapurida; Cattrall, Robert W; Kolev, Spas D

    2015-12-08

    Poly(vinyl chloride) (PVC) based polymer inclusion membranes (PIMs), with different concentrations of Cyphos® IL 104 as the membrane extractant/carrier, were studied for their ability to extract Au(III) from hydrochloric acid solutions. Some of the PIMs also contained one of the following plasticizers or modifiers: 2-nitrophenyloctyl ether, dioctylphthalate, 1-dodecanol, 1-tetradecanol, or tri(2-ethylhexyl) phosphate. The best performance, in terms of extraction rate and amount of Au(III) extracted, was exhibited by a PIM consisting of 25 wt% Cyphos(®) IL 104, 5 wt% 1-dodecanol, and 70 wt% PVC. An almost complete back-extraction of the Au(III) extracted from this membrane was achieved by using a 0.10 mol L(-1) Na₂SO₃ receiver solution at pH 8. The stoichiometry of the extracted Au(III)/Cyphos® IL 104 adduct was determined as [P]⁺ [AuCl₄](-) H⁺ [PO₂](-) where [P]⁺ and [PO₂](-) represent trihexyl(tetradecyl) phosphonium and bis(2,4,4-trimethylpentyl) phosphinate ions, respectively. Back-extraction of Au(III) is suggested to occur by reduction of Au(III) to Au(I), with the formation of the species [Au(SO₃)₂](3-) in the aqueous receiver solution. Loss of 1-dodecanol from the newly developed PIM to the aqueous solutions in contact with it was observed, which indicated that this membrane was suitable for single use in the efficient recovery of Au(III) from hydrochloric acid solutions of electronic scrap or recycled jewelry.

  15. Evaluation of esterification and membrane based solvent extraction as methods for the recovery of short chain volatile fatty acids from slaughterhouse blood anaerobic mixed fermentation

    OpenAIRE

    Plácido, Jersson; Zhang, Yue

    2017-01-01

    Two routes, esterification and membrane based solvent extraction, were tested for their efficiency to extract volatile fatty acids (VFA) (acetic, propionic, butyric, iso-butyric, iso-valeric and valeric acids) produced from the anaerobic-mixed fermentation of slaughterhouse blood. A range of operational parameters and reagents were assessed to optimize each system. Esterification recovered VFA as methyl esters with the production of ammonium sulphate as a value-added by-product of the esterif...

  16. Studies on the biocidal and cell membrane disruption potentials of stem bark extracts of Afzelia africana (Smith

    Directory of Open Access Journals (Sweden)

    DAVID A AKINPELU

    2009-01-01

    Full Text Available We had recently reported antibacterial activity in the crude extract of the stem bark of Afzelia africana (Akinpelu et al., 2008. In this study, we assessed the biocidal and cell membrane disruption potentials of fractions obtained from the crude extract of the plant. The aqueous (AQ and butanol (BL fractions exhibited appreciable antibacterial activities against the test bacteria. The minimum inhibitory concentrations of the AQ and BL fractions ranged between 0.313 and 2.5 mg/ml, while their minimum bactericidal concentrations varied between 0.625 and 5.0 mg/ml. Also, the AQ fraction killed about 95.8% of E. coli cells within 105 min at a concentration of 5 mg/ml, while about 99.1% of Bacillus pumilus cells were killed by this fraction at the same concentration and exposure time. A similar trend was observed for the BL fraction. At a concentration of 5 mg/ml, the butanol fraction leaked 9.8 μg/ml of proteins from E. coli cells within 3 h, while the aqueous fraction leaked 6.5 μg/ml of proteins from the same organisms at the same concentration and exposure time. We propose that the stem bark of Afzelia africana is a potential source of bioactive compounds of importance to the pharmaceutical industry.

  17. An Interesting Case of Intramuscular Myxoma with Scapular Bone Lysis

    Directory of Open Access Journals (Sweden)

    Jérôme Tirefort

    2017-01-01

    Full Text Available Introduction. Intramuscular myxoma is a rare benign primitive tumor of the mesenchyme founded at the skeletal muscle level; it presents itself like an unpainful, slow-growing mass. Myxomas with bone lysis are even more rare; only 7 cases have been reported in the English literature, but never at the shoulder level. Case Presentation. We describe an 83-year-old patient with a growing mass in the deltoid muscle with unique scapular lysis, without any symptom. Magnetic resonance imaging (MRI and a biopsy were performed and the diagnosis of intramuscular myxoma has been retained. In front of this diagnosis of nonmalignant lesion, the decision of a simple follow-up was taken. One year after this decision, the patient was still asymptomatic. Conclusion. In the presence of an intramuscular growing mass with associated bone lysis, intramuscular myxoma as well as malignant tumor should be evoked. MRI has to be part of the initial radiologic appraisal but biopsy is essential to confirm the diagnosis. By consensus, the standard treatment is surgical excision but conservative treatment with simple follow-up can be an option.

  18. Morphometric Changes of the Socket after Site Preservation Using Nanobone and Collagen Membrane or Stypro Versus Extraction Alone

    Directory of Open Access Journals (Sweden)

    Salahi S

    2015-06-01

    Full Text Available Statement of Problem: The long-term success of a dental implant relies on implant osseointegration into native and viable bone, implant placement in an ideal position, and optimal hard and soft tissue contour. This requires the presence of sufficient alveolar bone volume, good alveolar ridge (Practically with no sign of atrophy and good surgical technique. Objectives: The aim of this randomized controlled clinical study was to evaluate morphometric changes after different alveolar ridge preservation procedures. Materials and Methods: In this study, 33 patients who had single-rooted premolar, which needed to be extracted, were recruited. Patients were randomly divided into 3 groups and after tooth extraction the following treatments were administered: in group A: NanoBone and a collagen membrane; in group B: NanoBone and Stypro; and in group C: natural healing. The following clinical parameters were evaluated at baseline and 6 months after the extraction: buccolingual width, midbuccal height (with the use of a custom made stent and width of keratinized gingiva. For data analysis, Paired t-test,one-way ANOVA and Tukey’s tests were used. Results: The average reduction in the buccolingual width, midbuccal height and keratinized gingiva was as follows: group A: 1.18±0.6, 0.64±0.92 and 3.45±1.75 mm; group B: 2.18±0.75, 0.73±0.78 and 4.73±0.9 mm; and group C: 1±0.89, 2.36±1.21 and 5±0.63 mm, respectively. Moreover, a significantly reduced resorption was found in both the buccolingual width and the width of keratinized gingiva in group A as compared to groups B and C (p<0.05. Conclusions: This study showed that the use of collagen membrane+Nano bone (group A can significantly reduce the horizontal resorption of the alveolar ridge and keratinized tissue more effectively than stypro+Nano bone (group B and blood clot alone and natural healing (group C.

  19. Optimization of cyanide extraction from wastewater using emulsion liquid membrane system by response surface methodology.

    Science.gov (United States)

    Xue, Juan Qin; Liu, Ni Na; Li, Guo Ping; Dang, Long Tao

    To solve the disposal problem of cyanide wastewater, removal of cyanide from wastewater using a water-in-oil emulsion type of emulsion liquid membrane (ELM) was studied in this work. Specifically, the effects of surfactant Span-80, carrier trioctylamine (TOA), stripping agent NaOH solution and the emulsion-to-external-phase-volume ratio on removal of cyanide were investigated. Removal of total cyanide was determined using the silver nitrate titration method. Regression analysis and optimization of the conditions were conducted using the Design-Expert software and response surface methodology (RSM). The actual cyanide removals and the removals predicted using RSM analysis were in close agreement, and the optimal conditions were determined to be as follows: the volume fraction of Span-80, 4% (v/v); the volume fraction of TOA, 4% (v/v); the concentration of NaOH, 1% (w/v); and the emulsion-to-external-phase volume ratio, 1:7. Under the optimum conditions, the removal of total cyanide was 95.07%, and the RSM predicted removal was 94.90%, with a small exception. The treatment of cyanide wastewater using an ELM is an effective technique for application in industry.

  20. Simultaneous electromembrane extraction of cationic and anionic herbicides across hollow polymer inclusion membranes with a bubbleless electrode.

    Science.gov (United States)

    Mamat, Nor Akma; See, Hong Heng

    2017-06-30

    A new electric-field driven extraction approach based on the integration of a bubbleless electrode into the electromembrane extraction (EME) across hollow polymer inclusion membranes (HPIMs) was demonstrated for the first time. The bubbleless electrode was prepared based on an in-situ synthesised polyacrylamide within a fused silica capillary. The electrode functions as a salt bridge, which conducts the electrical current between the acceptor phase in the lumen of the HPIM and the acceptor solution in the reservoir connected to a high voltage supply through a platinum electrode. Two types of HPIMs were employed, which consisted of desired proportions of cellulose acetate as base polymer, tris(2-ethylhexyl)phosphate as plasticizer, and di-(2-ethylhexyl)phosphoric acid as anionic carrier or Aliquat 336 as cationic carrier, respectively. The EME strategy was evaluated for the simultaneous determination of cationic quaternary ammonium and anionic chlorophenoxy acetic acid herbicides present in the river water, respectively. The analysis was carried out using capillary electrophoresis coupled with UV and contactless conductivity detection. Under the optimised conditions, enrichment factors in the range of 152-185-fold were obtained from 4mL of river water sample with a 20min extraction time and an applied voltage of 3000V. The proposed method provided good linearity with correlation coefficients ranging from 0.9982 to 0.9997 over a concentration range of 1-1000μg/L. The detection limits of the method for the herbicides were in the range of 0.3-0.4μg/L, with relative standard deviations of between 4.8% and 8.5%. The relative recoveries obtained when analysing the spiked river water ranged from 99.1% to 100%. A comparison was also made between the newly developed approach with the conventional EME setup by placing the platinum electrode directly in the lumen of the HPIMs. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2015-01-01

    Roč. 1389, APR (2015), s. 1-7 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * in- line coupling * supported liquid membrane extraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.926, year: 2015

  2. In-line coupling of supported liquid membrane extraction to capillary electrophoresis for simultaneous analysis of basic and acidic drugs in urine

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel

    2017-01-01

    Roč. 1519, OCT (2017), s. 137-144 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : supported liquid membrane extraction * capillary electrophoresis * in- line sample treatment Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  3. In-line coupling of supported liquid membrane extraction to capillary electrophoresis for simultaneous analysis of basic and acidic drugs in urine

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel

    2017-01-01

    Roč. 1519, OCT (2017), s. 137-144 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : supported liquid membrane extraction * capillary electrophoresis * in-line sample treatment Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 3.981, year: 2016

  4. Sensitivity enhancement in direct coupling of supported liquid membrane extractions to capillary electrophoresis by means of transient isotachophoresis and large electrokinetic injections

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2015-01-01

    Roč. 1389, APR (2015), s. 1-7 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * in-line coupling * supported liquid membrane extraction Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.926, year: 2015

  5. COMPARISON OF DETERGENTS FOR EXTRACTION AND ION-EXCHANGE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY OF SENDAI VIRUS MEMBRANE-PROTEINS

    NARCIS (Netherlands)

    WELLING, GW; FEIJLBRIEF, M; ORVELL, C; VANEDE, J; WELLINGWESTER, S

    1992-01-01

    The integral membrane proteins of Sendai virus, haemagglutinin-neuraminidase (HN) and fusion protein (F) were extracted from purified virions with a non-ionic and two zwitterionic detergents, i.e.. pentaethylene glycol monolauryl ether (C-12E5), lauryldimethylamine oxide (LDAO) and

  6. Micro-electromembrane extraction using multiple free liquid membranes and acceptor solutions - Towards selective extractions of analytes based on their acid-base strength.

    Science.gov (United States)

    Kubáň, Pavel; Seip, Knut Fredrik; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2016-11-02

    This work investigated selective micro-electromembrane extractions (μ-EMEs) of the colored indicators metanil yellow and congo red (visual proof-of-principle) and the small drug substances nortriptyline, papaverine, mianserin, and citalopram (model analytes) based on their acid-base strength. With two free liquid membranes (FLMs), the target analytes were extracted from aqueous donor solution, across FLM 1 (1-pentanol, 1-ethyl-2-nitrobenzene (ENB) or 4-nitrocumene (4-NC)), into aqueous acceptor solution 1, further across FLM 2 (1-pentanol, ENB or 4-NC), and finally into aqueous acceptor solution 2. All phases had volumes between 1.0 and 1.5 μL and extractions were promoted by 200-300 V d.c. applied across the five-phase μ-EME system formed in a perfluoroalkoxy capillary tubing. The anode was located in acceptor solution 2 and the cathode was located in donor solution for μ-EMEs of acidic analytes, and locations of the electrodes were vice versa for μ-EMEs of basic analytes. After μ-EME, donor solution and acceptor solution 1 and 2 were analyzed by capillary electrophoresis or liquid chromatography-mass spectrometry. The model analytes migrated efficiently in the proposed μ-EME system, their migration behavior was controlled by pH in aqueous solutions and their selective fractionation into acceptor solution 1 and 2 was demonstrated based on their acid-base strength. Under optimal conditions, acceptor solution 2 contained 60% nortriptyline (pK a  = 10.5) and less than 1% papaverine (pK a  = 6.0) and acceptor solution 1 contained 17% nortriptyline and 27% papaverine after 15 min of μ-EME. The five-phase μ-EME system was also compatible with human plasma samples. Work is in progress to further increase the fractionation capability, and to implement the concept into microfluidic platforms. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Evaluation of in-situ fatty acid extraction protocols for the analysis of staphylococcal cell membrane associated fatty acids by gas chromatography.

    Science.gov (United States)

    Crompton, Marcus J; Dunstan, R Hugh

    2018-05-01

    The composition and integrity of the bacterial cytoplasmic membrane is critical to the survival of staphylococci in dynamic environments and it is important to investigate how the cell membrane responds to changes in the environmental conditions. The staphylococcal membrane differs from eukaryotic and many other bacterial cell membranes by having a high abundance of branch fatty acids and relatively few unsaturated fatty acids. The range of available methods for extraction and efficient analyses of staphylococcal fatty acids was initially appraised to identify the best potential procedures for appraisal. Staphylococcus aureus subsp. aureus Rosenbach (ATCC® 29213) was grown under optimal conditions to generate a cell biomass to compare the efficiencies of three approaches to extract and prepare methyl esters of the membrane fatty acids: (1) acidic direct transesterification of lipids, (2) modified basic direct transesterification of membrane lipids with adjusted reaction times and temperatures, and (3) base catalysed hydrolysis followed by acid catalysed esterification in two separate chemical reactions (MIDI process). All methods were able to extract fatty acids from the cell mass effectively where these lipids represented approximately 5% of the cellular dry mass. The acidic transesterification method had the least number of steps, the lowest coefficient of variation at 6.7% and good resistance to tolerating water. Basic transesterification was the least accurate method showing the highest coefficient of variation (26%). The MIDI method showed good recoveries, but had twice the number of steps and a coefficient of variation of 16%. It was also found that there was no need to use an anti-oxidant such as BHT for the protection of polyunsaturated fatty acids when the GC-MS injection liner was clean. It was concluded that the acidic transesterification procedures formed the most efficient and reproducible method for the analyses of staphylococcal membrane fatty acids

  8. The interaction of aurein 2.5 with fungal membranes.

    Science.gov (United States)

    Dennison, Sarah R; Morton, Leslie H G; Harris, Frederick; Phoenix, David A

    2014-07-01

    Aurein 2.5 (GLFDIVKKVVGAFGSL-NH2) is an antimicrobial peptide, which was seen to have activity against Stachybotris chartarum, Penicillium roseopurpureum and Aspergillus flavus with minimum fungicidal concentrations in the range 250-500 μM. S. chartarum showed enhanced susceptibility to lysis as compared to P. roseopurpureum and A. flavus, (44, 26 and 28 % respectively). Monolayers formed from lipid membrane extracts derived from S. chartarum, P. roseopurpureum and A. flavus showed maximal surface pressure changes of 13.5, 10.3 and 10.2 mN m(-1) respectively. However, aurein 2.5 adopted similar levels of α-helical structure (circa 45 %) in the presence of vesicles formed from membrane lipid extracts derived from all three fungi. These data imply that differential activity is not due to targeting and membrane association but linked to the ability of the bound peptide to lyse the cells. At sterol levels mimetic of eukaryotic systems, high levels of α-helical structure (circa 50 %) were also observed and hence similar binding. However, enhanced sterol levels (>0.6) led to a reduction in monolayer membrane interaction, suggesting that the sterols influence efficacy. Consistent with this suggestion, thermodynamic analysis showed that the peptide was able to destabilise model fungal monolayers, as indicated by negative values of ∆Gmix.

  9. RNA integrity as a quality indicator during the first steps of RNP purifications : A comparison of yeast lysis methods

    Directory of Open Access Journals (Sweden)

    Jansen Ralf-Peter

    2004-10-01

    Full Text Available Abstract Background The completion of several genome-sequencing projects has increased our need to assign functions to newly identified genes. The presence of a specific protein domain has been used as the determinant for suggesting a function for these new genes. In the case of proteins that are predicted to interact with mRNA, most RNAs bound by these proteins are still unknown. In yeast, several protocols for the identification of protein-protein interactions in high-throughput analyses have been developed during the last years leading to an increased understanding of cellular proteomics. If any of these protocols or similar approaches shall be used for the identification of mRNA-protein complexes, the integrity of mRNA is a critical factor. Results We compared the effect of different lysis protocols on RNA integrity. We report dramatic differences in RNA stability depending on the method used for yeast cell lysis. Glass bead milling and French Press lead to degraded mRNAs even in the presence of RNase inhibitors. Thus, they are not suitable to purify intact mRNP complexes or to identify specific mRNAs bound to proteins. Conclusion We suggest a novel protocol, grinding deep-frozen cells, for the preparation of protein extracts that contain intact RNAs, as lysis method for the purification of mRNA-protein complexes from yeast cells.

  10. Droplet Microfluidics for Compartmentalized Cell Lysis and Extension of DNA from Single-Cells

    Science.gov (United States)

    Zimny, Philip; Juncker, David; Reisner, Walter

    Current single cell DNA analysis methods suffer from (i) bias introduced by the need for molecular amplification and (ii) limited ability to sequence repetitive elements, resulting in (iii) an inability to obtain information regarding long range genomic features. Recent efforts to circumvent these limitations rely on techniques for sensing single molecules of DNA extracted from single-cells. Here we demonstrate a droplet microfluidic approach for encapsulation and biochemical processing of single-cells inside alginate microparticles. In our approach, single-cells are first packaged inside the alginate microparticles followed by cell lysis, DNA purification, and labeling steps performed off-chip inside this microparticle system. The alginate microparticles are then introduced inside a micro/nanofluidic system where the alginate is broken down via a chelating buffer, releasing long DNA molecules which are then extended inside nanofluidic channels for analysis via standard mapping protocols.

  11. Geothermal Thermoelectric Generation (G-TEG) with Integrated Temperature Driven Membrane Distillation and Novel Manganese Oxide for Lithium Extraction

    Energy Technology Data Exchange (ETDEWEB)

    Renew, Jay [Southern Research Inst., Birmingham, AL (United States); Hansen, Tim [Southern Research Inst., Birmingham, AL (United States)

    2017-06-01

    Southern Research Institute (Southern) teamed with partners Novus Energy Technologies (Novus), Carus Corporation (Carus), and Applied Membrane Technology, Inc. (AMT) to develop an innovative Geothermal ThermoElectric Generation (G-TEG) system specially designed to both generate electricity and extract high-value lithium (Li) from low-temperature geothermal brines. The process combined five modular technologies including – silica removal, nanofiltration (NF), membrane distillation (MD), Mn-oxide sorbent for Li recovery, and TEG. This project provides a proof of concept for each of these technologies. The first step in the process is silica precipitation through metal addition and pH adjustment to prevent downstream scaling in membrane processes. Next, the geothermal brine is concentrated with the first of a two stage MD system. The first stage MD system is made of a high-temperature material to withstand geothermal brine temperatures up to 150C.° The first stage MD is integrated with a G-TEG module for simultaneous energy generation. The release of energy from the MD permeate drives heat transfer across the TE module, producing electricity. The first stage MD concentrate is then treated utilizing an NF system to remove Ca2+ and Mg2+. The NF concentrate will be disposed in the well by reinjection. The NF permeate undergoes concentration in a second stage of MD (polymeric material) to further concentrate Li in the NF permeate and enhance the efficiency of the downstream Li recovery process utilizing a Mn-oxide sorbent. Permeate from both the stages of the MD can be beneficially utilized as the permeates will contain less contaminants than the feed water. The concentrated geothermal brines are then contacted with the Mn-oxide sorbent. After Li from the geothermal brine is adsorbed on the sorbent, HCl is then utilized to regenerate the sorbent and recover the Li. The research and development project showed that the Si removal goal (>80%) could

  12. Tissue damage and embryonic malformation induced by aqueous extract of Pteridium aquilinum on chorioallantoic membrane of chick embryo (CAM

    Directory of Open Access Journals (Sweden)

    Amanda Leitolis

    2017-06-01

    Full Text Available The aim of this study was evaluate the effects of Bracken fern (BF (Pteridium aquilinum (L. Kuhn. on biological systems. When consumed by animals can cause acute intoxication, hematuria, biochemistry alterations and cancer. To humans the toxicity is associated with its intake on contaminated ground water or milk and inhalation of its spores. In order to check the BF aqueous extract (AEB deleterious effects on animals blood vessels system, chick embryo chorioallantoic membrane (CAM was used. It were applying on CAM 0.1, 0.5, 1, 5, 10 e 15 µg/mL of AEB and saline as control. The angiogenesis was analyzed and the vascular density index (VDI calculated. The CAM samples were prepared and stained with H&E to evaluation of microvessels, Masson’s trichrome to characterize collagen and fibrin deposition and Picro-sirius used to evaluate collagen using polarized light. Also the morphological aspects of embryos were analysed. We observe on the results of neovascularization that AEB did not change significantly the number of vessels/mm², however, membranes treated with AEB (5 or 10 µg/mL exhibit opacity and tissue fibrosis, both signs of inflammation. Histological analysis with Masson's trichrome and picro-sirius on tissues exposed to AEB respectively has shown increased collagen fibers and presence of fibrilar collagen. The embryos exposed to concentrations of 5 or 10 µg/mL AEB, showed changes as poor face formation and poor closing of abdominal wall. The highest concentration of AEB (15 µg/mL was lethal to embryos. Although significant effects on the CAM’s vasculature has not observed, tissue aggression was detected, a desmoplasia (an extensive inflammatory signal triggered by tissue injury, changes caused on embryos as well as the presence of toxic substances in the AEB show us an important and deleterious pathway of this bracken fern extract on its intoxicants effects on humans and animals, and even cancer or the death of animals.

  13. In-tube electro-membrane extraction with a sub-microliter organic solvent consumption as an efficient technique for synthetic food dyes determination in foodstuff samples.

    Science.gov (United States)

    Bazregar, Mohammad; Rajabi, Maryam; Yamini, Yadollah; Asghari, Alireza; Abdossalami asl, Yousef

    2015-09-04

    A simple and efficient extraction technique with a sub-microliter organic solvent consumption termed as in-tube electro-membrane extraction (IEME) is introduced. This method is based upon the electro-kinetic migration of ionized compounds by the application of an electrical potential difference. For this purpose, a thin polypropylene (PP) sheet placed inside a tube acts as a support for the membrane solvent, and 30μL of an aqueous acceptor solution is separated by this solvent from 1.2mL of an aqueous donor solution. This method yielded high extraction recoveries (63-81%), and the consumption of the organic solvent used was only 0.5μL. By performing this method, the purification is high, and the utilization of the organic solvent, used as a mediator, is very simple and repeatable. The proposed method was evaluated by extraction of four synthetic food dyes (Amaranth, Ponceau 4R, Allura Red, and Carmoisine) as the model analytes. Optimization of variables affecting the method was carried out in order to achieve the best extraction efficiency. These variables were the type of membrane solvent, applied extraction voltage, extraction time, pH range, and concentration of salt added. Under the optimized conditions, IEME-HPLC-UV provided a good linearity in the range of 1.00-800ngmL(-1), low limits of detection (0.3-1ngmL(-1)), and good extraction repeatabilities (RSDs below 5.2%, n=5). It seems that this design is a proper one for the automation of the method. Also the consumption of the organic solvent in a sub-microliter scale, and its simplicity, high efficiency, and high purification can help one getting closer to the objectives of the green chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Staphylococcal α-hemolysin is neurotoxic and causes lysis of brain cells in vivo and in vitro.

    Science.gov (United States)

    Dahlberg, Daniel; Mariussen, Espen; Goverud, Ingeborg Løstegaard; Tønjum, Tone; Mæhlen, Jan; Antal, Ellen-Ann; Hassel, Bjørnar

    2015-05-01

    Formation of a bacterial brain abscess entails loss of brain cells and formation of pus. The mechanisms behind the cell loss are not fully understood. Staphylococcus aureus, a common cause of brain abscesses, produces various exotoxins, including α-hemolysin, which is an important factor in brain abscess formation. α-Hemolysin may cause cytolysis by forming pores in the plasma membrane of various eukaryotic cells. However, whether α-hemolysin causes lysis of brain cells is not known. Nor is it known whether α-hemolysin in the brain causes cell death through pore formation or by acting as a chemoattractant, recruiting leukocytes and causing inflammation. Here we show that α-hemolysin injected into rat brain causes cell damage and edema formation within 30 min. Cell damage was accompanied by an increase in extracellular concentrations of zinc, GABA, glutamate, and other amino acids, indicating plasma membrane damage, but leukocytic infiltration was not seen 0.5-12h after α-hemolysin injection. This was in contrast to injection of S. aureus, which triggered extensive infiltration with neutrophils within 8h. In vitro, α-hemolysin caused concentration-dependent lysis of isolated nerve endings and cultured astrocytes. We conclude that α-hemolysin contributes to the cell death inherent in staphylococcal brain abscess formation as a pore-forming neurotoxin. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Miniature acoustic wave lysis system and uses thereof

    Energy Technology Data Exchange (ETDEWEB)

    Branch, Darren W.; Vreeland, Erika Cooley; Smith, Gennifer Tanabe

    2016-12-06

    The present invention relates to an acoustic lysis system including a disposable cartridge that can be reversibly coupled to a platform having a small, high-frequency piezoelectric transducer array. In particular, the system releases viable DNA, RNA, and proteins from human or bacterial cells, without chemicals or additional processing, to enable high-speed sample preparation for clinical point-of-care medical diagnostics and use with nano/microfluidic cartridges. Also described herein are methods of making and using the system of the invention.

  16. Direct uranium extraction from dihydrate and hemi-dihydrate wet process phosphoric acids by liquid emulsion membrane

    International Nuclear Information System (INIS)

    El-Hazek, N.T.; El Sayed, M.S.

    2003-01-01

    A new liquid emulsion membrane (LEM) process for uranium extraction from either dihydrate 28-30% P 2 O 5 (DH) or hemi-dihydrate 42-45% P 2 O 5 (HDH) wet process phosphoric acid is proposed. In this process, the organic component of the LEM is composed of a synergistic mixture of 0.1M di-2-ethyl hexyl phosphoric acid (DEHPA) and 0.025M trioctyl phosphine oxide (TOPO) with 4% Span 80. The internal or the strip acid phase is composed of 0.5M citric acid. The prepared LEM was proved to be stable in 42-45% P 2 O 5 acid concentration range and can, therefore, be applied to the phosphoric acid produced by the hemi-dihydrate process. After breakdown of the loaded emulsion, the uranyl citrate in the internal strip phase is separated by adding methanol followed by its calcination to the orange oxide. Most of the reagents used are recycled. The proposed process is characterized by simplicity, practically closed operation cycle in addition to lower capital and operating costs. (author)

  17. Determination of polybrominated diphenyl ethers at trace levels in environmental waters using hollow-fiber microporous membrane liquid-liquid extraction and gas chromatography-mass spectrometry.

    Science.gov (United States)

    Fontanals, Núria; Barri, Thaer; Bergström, Staffan; Jönsson, Jan-Ake

    2006-11-10

    In this study, we present a simple and easy-to-use extraction method that is based on a hollow-fiber microporous membrane liquid-liquid extraction (HF-MMLLE), as an extraction technique, followed by gas chromatography-mass spectrometry (GC-MS) to determine a group of brominated flame retardants (BFRs), polybrominated diphenyl ethers (PBDEs), at trace levels in aqueous samples. The hollow-fiber membrane (HF) filled with organic solvent was immersed into the aqueous sample, spiked with the analytes at ng l(-1) level, and stirred for 60 min. The proposed method could attain enrichment factors (E(e)) up to 5200 times, after optimising parameters, such as organic solvent, stirring speed and extraction time, that affect the extraction. The HF-MMLLE-GC-MS method was successfully applied to the extraction of PBDEs from tap, river and leachate water samples with spike recoveries ranging from 85% to 110%. The method validation with reagent and leachate water samples provided good linearity, detection limits of 1.1 ng l(-1) or lower, both in reagent and leachate water, as well as satisfactory precision in terms of repeatability and reproducibility with values of % relative standard deviation (%RSD) lower than 8.6 and 16.9, respectively.

  18. Improved in-tube electro-membrane extraction followed by high-performance liquid chromatography for simple and selective determination of ionic compounds: Optimization by central composite design.

    Science.gov (United States)

    Bazregar, Mohammad; Rajabi, Maryam; Yamini, Yadollah; Asghari, Alireza

    2017-07-01

    In this work, an efficient sample clean-up method, named in-tube electro-membrane extraction, is modified to resolve the formation of bubbles in the extraction process. This modified method is applied for the extraction of two model analytes including tartrazine and sunset yellow from food samples. The method is based on the electro-kinetic migration of ionized compounds by the application of an electrical potential difference, and on this basis the analytes under investigation, as anionic compounds, simply migrate from the donor phase and concentrate in the acceptor phase. A thin polypropylene sheet placed in the tube acts as a support for the membrane solvent, and it separates 30 μL of the aqueous acceptor from 1.2 mL of the aqueous donor. This setup can be used to solve the problem of extracting highly hydrophilic analytes. Response surface methodology is used for optimization of the experimental parameters so that under the optimized conditions, the method provides a good linearity in the range of 50-1000 ng/mL, low limits of detection (15-25 ng/mL), good extraction repeatabilities (relative standard deviations below 8.1%, n = 5), and high extraction recoveries (54-76%). © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. EFFECT OF MATRICES ON PERCENT EXTRACTION OF SILVER (II FROM BLACK/WHITE PRINTING PHOTOGRAPHIC WASTE USING EMULSION LIQUID MEMBRANE TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Imam Santoso

    2010-06-01

    Full Text Available Extraction of silver (I has been studied from black/white printing photographic waste by emulsion liquid membrane technique. Composition emulsion at the membrane phase was cerosene as solvent, sorbitan monooleat (span 80 as surfactant, dimethyldioctadesyl-ammonium bromide as carrier and as internal phase was HNO3. Optimum condition was obtained: ratio of internal phase volume and membrane phase volume was 1:1 : concentration of surfactant was 2% (v/v : time of making emulsion was 20 second : rate of stiring emulsion was 1100 rpm : rest time emulsion was 3 second : rate of emulsion volume and external phase volume was 1:5 : emulsion contact rate 500 rpm : emulsion contact time was 40 second : concentration of silver thiosulfate as external phase was 100 ppm : pH of external phase was 3 and pH of internal phase was 1. Optimum condition was applied in silver(I extraction from black/white printing photographic waste. It was obtained 77.33% average which 56.06% silver (I average of internal phase and 22.66% in the external phase. Effect of matrices ion decreased silver(I percent extraction from 96,37% average to 77.33% average. Keyword: photographics waste, silver extraction

  20. The mechanism of action of Russian propolis ethanol extracts against two antibiotic-resistant biofilm-forming bacteria.

    Science.gov (United States)

    Bryan, J; Redden, P; Traba, C

    2016-02-01

    The interaction between antibiotic-resistant Staphylococcus aureus and antibiotic-sensitive Escherichia coli biofilm-forming bacteria and Russian propolis ethanol extracts was evaluated. In this study, bacterial cell death occurred when the cell membranes of bacteria interacted specifically with the antibacterial compounds found in propolis. In order to understand the Russian propolis ethanol extract mechanism of action, microscopy and bacterial lysis studies were conducted. Results uncovered from these experiments imply that the mechanism of action of Russian propolis ethanol extracts is structural rather than functional. The results obtained throughout this study demonstrate cell membrane damage, resulting in cell lysis and eventually bacterial death. Most strains of bacteria and subsequently biofilms, have evolved and have altered their chemical composition in an attempt to protect themselves from antibiotics. The resistant nature of bacteria stems from the chemical rather than the physical means of inactivation of antibiotics. The results uncovered in this work demonstrate the potential application of Russian propolis ethanol extracts as a very efficient and effective method for bacterial and biofilm inactivation. © 2015 The Society for Applied Microbiology.

  1. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

    Science.gov (United States)

    Mohamed, Jamaludin; Shing, Saw Wuan; Md Idris, Muhd Hanis; Budin, Siti Balkis; Zainalabidin, Satirah

    2013-01-01

    OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days. RESULTS: The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. CONCLUSION: The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients. PMID:24212844

  2. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes.

    Science.gov (United States)

    Mohamed, Jamaludin; Shing, Saw Wuan; Idris, Muhd Hanis Md; Budin, Siti Balkis; Zainalabidin, Satirah

    2013-10-01

    The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2) against red blood cell (RBC) membrane oxidative stress in rats with streptozotocin-induced diabetes. Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each): control group (N), roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight) for 28 days. The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients.

  3. The protective effect of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2 against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes

    Directory of Open Access Journals (Sweden)

    Jamaludin Mohamed

    2013-10-01

    Full Text Available OBJECTIVES: The aim of this study was to investigate the protective effects of aqueous extracts of roselle (Hibiscus sabdariffa L. UKMR-2 against red blood cell (RBC membrane oxidative stress in rats with streptozotocin-induced diabetes. METHODS: Forty male Sprague-Dawley rats weighing 230-250 g were randomly divided into four groups (n = 10 rats each: control group (N, roselle-treated control group, diabetic group, and roselle-treated diabetic group. Roselle was administered by force-feeding with aqueous extracts of roselle (100 mg/kg body weight for 28 days. RESULTS: The results demonstrated that the malondialdehyde levels of the red blood cell membranes in the diabetic group were significantly higher than the levels in the roselle-treated control and roselle-treated diabetic groups. The protein carbonyl level was significantly higher in the roselle-treated diabetic group than in the roselle-treated control group but lower than that in the diabetic group. A significant increase in the red blood cell membrane superoxide dismutase enzyme was found in roselle-treated diabetic rats compared with roselle-treated control rats and diabetic rats. The total protein level of the red blood cell membrane, osmotic fragility, and red blood cell morphology were maintained. CONCLUSION: The present study demonstrates that aqueous extracts of roselle possess a protective effect against red blood cell membrane oxidative stress in rats with streptozotocin-induced diabetes. These data suggest that roselle can be used as a natural antioxidative supplement in the prevention of oxidative damage in diabetic patients.

  4. Liquid-phase membrane extraction of targeted pesticides from manufacturing wastewaters in a hollow fibre contactor with feed-stream recycle.

    Science.gov (United States)

    Đorđević, Jelena; Vladisavljević, Goran T; Trtić-Petrović, Tatjana

    2017-01-01

    A two-phase membrane extraction in a hollow fibre contactor with feed-stream recycle was applied to remove selected pesticides (tebufenozide, linuron, imidacloprid, acetamiprid and dimethoate) from their mixed aqueous solutions. The contactor consisted of 50 polypropylene hollow fibres impregnated with 5% tri-n-octylphosphine oxide in di-n-hexyl ether. For low-polar pesticides with log P ≥ 2 (tebufenozide and linuron), the maximum removal efficiency increased linearly from 85% to 96% with increasing the feed flow rate. The maximum removal efficiencies of more polar pesticides were significantly higher under feed recirculation (86%) than in a continuous single-pass operation (30%). It was found from the Wilson's plot that the mass transfer resistance of the liquid membrane can be neglected for low-polar pesticides. The pesticide removals from commercial formulations were similar to those from pure pesticide solutions, indicating that built-in adjuvants did not affect the extraction process.

  5. Simple hollow fiber renewal liquid membrane extraction method for pre-concentration of Cd(II) in environmental samples and detection by Flame Atomic Absorption Spectrometry

    International Nuclear Information System (INIS)

    Carletto, Jeferson Schneider; Luciano, Raquel Medeiros; Bedendo, Gizelle Cristina; Carasek, Eduardo

    2009-01-01

    A hollow fiber renewal liquid membrane (HFRLM) extraction method to determine cadmium (II) in water samples using Flame Atomic Absorption Spectrometry (FAAS) was developed. Ammonium O,O-diethyl dithiophosphate (DDTP) was used to complex cadmium (II) in an acid medium to obtain a neutral hydrophobic complex (ML 2 ). The organic solvent introduced to the sample extracts this complex from the aqueous solution and carries it over the poly(dimethylsiloxane) (PDMS) membrane, that had their walls previously filled with the same organic solvent. The organic solvent is solubilized inside the PDMS membrane, leading to a homogeneous phase. The complex strips the lumen of the membrane where, at higher pH, the complex Cd-DDTP is broken down and cadmium (II) is released into the stripping phase. EDTA was used to complex the cadmium (II), helping to trap the analyte in the stripping phase. A multivariate procedure was used to optimize the studied variables. The optimized variables were: sample (donor phase) pH 3.25, DDTP concentration 0.05% (m/v), stripping (acceptor phase) pH 8.75, EDTA concentration 1.5 x 10 -2 mol L -1 , extraction temperature 40 deg. C, extraction time 40 min, a solvent mixture N-butyl acetate and hexane (60/40%, v/v) with a volume of 100 μL, and addition of ammonium sulfate to saturate the sample. The sample volume used was 20 mL and the stripping volume was 165 μL. The analyte enrichment factor was 120, limit of detection (LOD) 1.3 μg L -1 , relative standard deviation (RSD) 5.5% and the working linear range 2-30 μg L -1 .

  6. Analysis of polycyclic aromatic hydrocarbons in soil and sediment with on-line coupled pressurised hot water extraction, hollow fibre microporous membrane liquid-liquid extraction and gas chromatography.

    Science.gov (United States)

    Kuosmanen, Kati; Hyötyläinen, Tuulia; Hartonen, Kari; Riekkola, Marja-Liisa

    2003-05-01

    Pressurised hot water extraction (PHWE) was coupled on-line via hollow fibre microporous membrane liquid-liquid extraction (HF-MMLLE) to gas chromatography (GC) and applied in the analysis of polycyclic aromatic hydrocarbons (PAHs) in soil and sediment. In this combination, the MMLLE unit serves as a trapping device for the extracted compounds. Simultaneously it cleans and concentrates the extract, which is then transferred on-line to the GC. No extra clean-up steps are required between the trapping and the transfer to GC. The on-line system gives excellent sensitivity while allowing small sample size. The method was linear, with limits of detection in the range 50-890 pg and limits of quantification 0.11-1.22 microg g(-1). The concentration enrichment factors obtained with the method ranged from 9 to 55. Comparison of the results with those obtained by other techniques confirmed the good performance.

  7. Water-soluble egg membrane enhances the immunoactivating properties of an Aloe vera-based extract of Nerium oleander leaves

    Directory of Open Access Journals (Sweden)

    Benson KF

    2016-11-01

    Full Text Available Kathleen F Benson,1 Robert A Newman,2,3 Gitte S Jensen1 1NIS Labs, Klamath Falls, OR, 2Department of Experimental Therapeutics, University of Texas MD Anderson Cancer Center, Houston, 3Nerium Biotechnology Inc, San Antonio, TX, USA Objective: To evaluate a blend of two natural ingredients on immune parameters relevant for their current topical use and potential support of microcirculation in skin tissue. Materials and methods: A blend (BL of Aloe vera-based Nerium oleander extract (NAE-8i, oleandrin-free and hydrolyzed water-soluble egg membrane (WSEM was applied to human whole-blood cultures for 24 hours, with each separate ingredient serving as a control. Immune-cell subsets were analyzed for expression levels of the activation markers CD69 and CD25. Culture supernatants were analyzed for cytokines, chemokines, and immunoregulating peptides. Results: BL increased CD69 expression on lymphocytes, monocytes, and CD3–CD56+ natural killer cells, and CD25 expression on natural killer cells. The number of CD69+CD25+ lymphocytes increased in cultures treated with BL and the separate ingredients. BL triggered production of multiple cytokines and chemokines, where CC chemokines MIP1α and MIP3α, as well as cytokines involved in wound healing – Groα, Groβ, ENA78, and fractalkine – reached levels manyfold above treatment with either NAE-8i or WSEM alone. Conclusion: Data on BL showed that WSEM strongly enhanced NAE-8i’s effects on immunoactivation in vitro. This has potential relevance for support of immunity in skin tissue, including antibacterial and antiviral defense mechanisms, wrinkle reduction, and wound care. Keywords: chemokines, cytokines, leukocyte activation

  8. Membrane assisted solvent extraction coupled with liquid chromatography tandem mass spectrometry applied to the analysis of alkylphenols in water samples.

    Science.gov (United States)

    Salgueiro-González, N; Turnes-Carou, I; Muniategui-Lorenzo, S; López-Mahía, P; Prada-Rodríguez, D

    2013-03-15

    This work describes the development and validation of a novel, simple, sensitive and environmental friendly analytical method for the determination of alkylphenols in different types of water samples. The methodology was based on a membrane assisted solvent extraction of only 15 mL of water sample with 500 μL of hexane in combination with liquid chromatography-electrospray ionization tandem mass spectrometry in negative mode (LC-ESI-MS/MS). Acquisition was performed in the multiple reaction monitoring (MRM) mode recording two transitions for the identification of the target compounds. Quantitation is based on the use of deuterated labelled standards as surrogate standards. The figures of merit were satisfactory in all cases: absolute recoveries were close to 50% for most investigated compounds and relative recoveries varied between 81 and 108%. Repeatability and intermediate precision were MQL) were lower than 0.04 μg L(-1) in all cases, which allow the achievement of the limits established by the Directive 2008/105/EC for surface and seawater samples and by the new proposal COM (2011) 876 final. The feasibility of the proposed method was demonstrated analyzing seawater, surface water and drinking water samples from different areas of A Coruña (Northwest of Spain). The analyses evidenced the presence of nonylphenol in seawater (MQL-0.13 μg L(-1)) and surface water samples (0.12-0.19 μg L(-1)). The highest concentration was observed in drinking water (0.25 μg L(-1)). Copyright © 2013 Elsevier B.V. All rights reserved.

  9. A common, non-optimal phenotypic endpoint in experimental adaptations of bacteriophage lysis time

    Directory of Open Access Journals (Sweden)

    Chantranupong Lynne

    2012-03-01

    Full Text Available Abstract Background Optimality models of evolution, which ignore genetic details and focus on natural selection, are widely used but sometimes criticized as oversimplifications. Their utility for quantitatively predicting phenotypic evolution can be tested experimentally. One such model predicts optimal bacteriophage lysis interval, how long a virus should produce progeny before lysing its host bacterium to release them. The genetic basis of this life history trait is well studied in many easily propagated phages, making it possible to test the model across a variety of environments and taxa. Results We adapted two related small single-stranded DNA phages, ΦX174 and ST-1, to various conditions. The model predicted the evolution of the lysis interval in response to host density and other environmental factors. In all cases the initial phages lysed later than predicted. The ΦX174 lysis interval did not evolve detectably when the phage was adapted to normal hosts, indicating complete failure of optimality predictions. ΦX174 grown on slyD-defective hosts which initially entirely prevented lysis readily recovered to a lysis interval similar to that attained on normal hosts. Finally, the lysis interval still evolved to the same endpoint when the environment was altered to delay optimal lysis interval. ST-1 lysis interval evolved to be ~2 min shorter, qualitatively in accord with predictions. However, there were no changes in the single known lysis gene. Part of ST-1's total lysis time evolution consisted of an earlier start to progeny production, an unpredicted phenotypic response outside the boundaries of the optimality model. Conclusions The consistent failure of the optimality model suggests that constraint and genetic details affect quantitative and even qualitative success of optimality predictions. Several features of ST-1 adaptation show that lysis time is best understood as an output of multiple traits, rather than in isolation.

  10. Antimicrobial actions of hexachlorophene: lysis and fixation of bacterial protoplasts.

    Science.gov (United States)

    Corner, T R; Joswick, H L; Silvernale, J N; Gerhardt, P

    1971-10-01

    Hexachlorophene was found to be both a lytic and a fixative agent for protoplasts isolated from Bacillus megaterium. Concentrations of 50 to 100 mug of drug per mg of original cell dry weight were required to lyse 4.4 x 10(9) protoplasts (2 mg of original cell dry weight). At higher drug concentrations, protoplasts became fixed against osmotic stress and reduced in sensitivity to disruption by n-butanol. Lower drug concentrations caused proportionate lysis in the protoplast population. Intact cells lost the ability to become plasmolyzed at these same hexachlorophene concentrations. Nonplasmolyzed, drug-treated cells were resistant to the action of lysozyme, whereas plasmolyzed, drug-treated cells were sensitive. But the sensitivity of isolated cell walls to lysozyme digestion was not markedly altered by hexachlorophene treatment. These effects appeared to be secondary in the killing of cells by hexachlorophene because they occurred at concentrations higher than the minimum lethal concentration.

  11. Tumor lysis syndrome in the emergency department: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Ñamendys-Silva SA

    2015-08-01

    Full Text Available Silvio A Ñamendys-Silva,1,2 Juan M Arredondo-Armenta,1 Erika P Plata-Menchaca,2 Humberto Guevara-García,1 Francisco J García-Guillén,1 Eduardo Rivero-Sigarroa,2 Angel Herrera-Gómez,1 1Department of Critical Care Medicine, Instituto Nacional de Cancerología, 2Department of Critical Care Medicine, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico Abstract: Tumor lysis syndrome (TLS is the most common oncologic emergency. It is caused by rapid tumor cell destruction and the resulting nucleic acid degradation during or days after initiation of cytotoxic therapy. Also, a spontaneous form exists. The metabolic abnormalities associated with this syndrome include hyperkalemia, hyperphosphatemia, hypocalcemia, hyperuricemia, and acute kidney injury. These abnormalities can lead to life-threatening complications, such as heart rhythm abnormalities and neurologic manifestations. The emergency management of overt TLS involves proper fluid resuscitation with crystalloids in order to improve the intravascular volume and the urinary output and to increase the renal excretion of potassium, phosphorus, and uric acid. With this therapeutic strategy, prevention of calcium phosphate and uric acid crystal deposition within renal tubules is achieved. Other measures in the management of overt TLS are prescription of hypouricemic agents, renal replacement therapy, and correction of electrolyte imbalances. Hyperkalemia should be treated quickly and aggressively as its presence is the most hazardous acute complication that can cause sudden death from cardiac arrhythmias. Treatment of hypocalcemia is reserved for patients with electrocardiographic changes or symptoms of neuromuscular irritability. In patients who are refractory to medical management of electrolyte abnormalities or with severe cardiac and neurologic manifestations, early dialysis is recommended.Keywords: tumor lysis syndrome, emergency department, emergency

  12. Isolation of Mycobacterium chelonei with the lysis-centrifugation blood culture technique.

    OpenAIRE

    Fojtasek, M F; Kelly, M T

    1982-01-01

    Mycobacterium chelonei was isolated from a patient by the lysis-centrifugation and the conventional two-bottle blood culture methods. The lysis-centrifugation method was significantly more sensitive and rapid than the conventional method in detecting and isolating this organism; quantitations done by this method were useful for monitoring response to therapy.

  13. Lab-on-a-Disc Platform for Automated Chemical Cell Lysis.

    Science.gov (United States)

    Seo, Moo-Jung; Yoo, Jae-Chern

    2018-02-26

    Chemical cell lysis is an interesting topic in the research to Lab-on-a-Disc (LOD) platforms on account of its perfect compatibility with the centrifugal spin column format. However, standard procedures followed in chemical cell lysis require sophisticated non-contact temperature control as well as the use of pressure resistant valves. These requirements pose a significant challenge thereby making the automation of chemical cell lysis on an LOD extremely difficult to achieve. In this study, an LOD capable of performing fully automated chemical cell lysis is proposed, where a combination of chemical and thermal methods has been used. It comprises a sample inlet, phase change material sheet (PCMS)-based temperature sensor, heating chamber, and pressure resistant valves. The PCMS melts and solidifies at a certain temperature and thus is capable of indicating whether the heating chamber has reached a specific temperature. Compared to conventional cell lysis systems, the proposed system offers advantages of reduced manual labor and a compact structure that can be readily integrated onto an LOD. Experiments using Salmonella typhimurium strains were conducted to confirm the performance of the proposed cell lysis system. The experimental results demonstrate that the proposed system has great potential in realizing chemical cell lysis on an LOD whilst achieving higher throughput in terms of purity and yield of DNA thereby providing a good alternative to conventional cell lysis systems.

  14. Lab-on-a-Disc Platform for Automated Chemical Cell Lysis

    Directory of Open Access Journals (Sweden)

    Moo-Jung Seo

    2018-02-01

    Full Text Available Chemical cell lysis is an interesting topic in the research to Lab-on-a-Disc (LOD platforms on account of its perfect compatibility with the centrifugal spin column format. However, standard procedures followed in chemical cell lysis require sophisticated non-contact temperature control as well as the use of pressure resistant valves. These requirements pose a significant challenge thereby making the automation of chemical cell lysis on an LOD extremely difficult to achieve. In this study, an LOD capable of performing fully automated chemical cell lysis is proposed, where a combination of chemical and thermal methods has been used. It comprises a sample inlet, phase change material sheet (PCMS-based temperature sensor, heating chamber, and pressure resistant valves. The PCMS melts and solidifies at a certain temperature and thus is capable of indicating whether the heating chamber has reached a specific temperature. Compared to conventional cell lysis systems, the proposed system offers advantages of reduced manual labor and a compact structure that can be readily integrated onto an LOD. Experiments using Salmonella typhimurium strains were conducted to confirm the performance of the proposed cell lysis system. The experimental results demonstrate that the proposed system has great potential in realizing chemical cell lysis on an LOD whilst achieving higher throughput in terms of purity and yield of DNA thereby providing a good alternative to conventional cell lysis systems.

  15. Vaccination of feedlot cattle with extracts and membrane fractions from two Mycoplasma bovis isolates results in strong humoral immune responses but does not protect against an experimental challenge.

    Science.gov (United States)

    Mulongo, Musa; Prysliak, Tracy; Perez-Casal, Jose

    2013-02-27

    Mycoplasma bovis is one of the most significant contributors to the bovine respiratory syndrome (BRD) that causes major losses in feedlot and dairy farms. Current experimental vaccines against M. bovis are ineffective and in some cases seem to enhance disease. Experimental infection with M. bovis induces a predominantly Th2 response and high levels of IgG1, which is an inferior opsonin and hence lacks protective capacity. In an attempt to induce a balanced (Th1/Th2) immune response, we have used CpG ODN 2007 as an adjuvant in a trial involving vaccination of cattle with M. bovis total extracts and/or membrane fractions and subsequent intranasal inoculation with an infective dose of M. bovis prepared from two different clinical isolates. Significant IgG1 serum responses were observed against both, extracts and fractions while IgG2 responses were significant against the extracts only. Proliferation of peripheral blood mononuclear cells (PBMC) after incubation with M. bovis cells was only observed in post-challenge samples of cattle vaccinated with both extracts and fractions but not in samples of cattle immunized with the membrane fractions alone. All groups showed transient weight losses and increased temperatures however, there were no significant differences in clinical parameters and survival rates between the groups. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium.

    Science.gov (United States)

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-05-01

    Electromembrane extraction was used for simultaneous sample cleanup and preconcentration of lithium from untreated human body fluids. The sample of a body fluid was diluted 100 times with 0.5 mM Tris solution and lithium was extracted by electromigration through a supported liquid membrane composed of 1-octanol into 100 mM acetic acid acceptor solution. Matrix compounds, such as proteins, red blood cells, and other high-molecular-weight compounds were efficiently retained on the supported liquid membrane. The liquid membrane was anchored in pores of a short segment of a polypropylene hollow fiber, which represented a low cost, single use, disposable extraction unit and was discarded after each use. Acceptor solutions were analyzed using capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4) D) and baseline separation of lithium was achieved in a background electrolyte solution consisting of 18 mM L-histidine and 40 mM acetic acid at pH 4.6. Repeatability of the electromembrane extraction-CE-C(4) D method was evaluated for the determination of lithium in standard solutions and real samples and was better than 0.6 and 8.2% for migration times and peak areas, respectively. The concentration limit of detection of 9 nM was achieved. The developed method was applied to the determination of lithium in urine, blood serum, blood plasma, and whole blood at both endogenous and therapeutic concentration levels. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Micro-electromembrane extraction using multiple free liquid membranes and acceptor solutions - Towards selective extractions of analytes based on their acid-base strength

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Seip, K. F.; Gjelstad, A.; Pedersen-Bjergaard, S.

    2016-01-01

    Roč. 943, NOV (2016), s. 64-73 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : multiple phase extraction * electromembrane extraction * plasma Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 4.950, year: 2016

  18. Micro-electromembrane extraction using multiple free liquid membranes and acceptor solutions - Towards selective extractions of analytes based on their acid-base strength

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Seip, K. F.; Gjelstad, A.; Pedersen-Bjergaard, S.

    2016-01-01

    Roč. 943, NOV (2016), s. 64-73 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : multiple phase extraction * electromembrane extraction * plasma Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.950, year: 2016

  19. NSF- and SNARE-mediated membrane fusion is required for nuclear envelope formation and completion of nuclear pore complex assembly in Xenopus laevis egg extracts.

    Science.gov (United States)

    Baur, Tina; Ramadan, Kristijan; Schlundt, Andreas; Kartenbeck, Jürgen; Meyer, Hemmo H

    2007-08-15

    Despite the progress in understanding nuclear envelope (NE) reformation after mitosis, it has remained unclear what drives the required membrane fusion and how exactly this is coordinated with nuclear pore complex (NPC) assembly. Here, we show that, like other intracellular fusion reactions, NE fusion in Xenopus laevis egg extracts is mediated by SNARE proteins that require activation by NSF. Antibodies against Xenopus NSF, depletion of NSF or the dominant-negative NSF(E329Q) variant specifically inhibited NE formation. Staging experiments further revealed that NSF was required until sealing of the envelope was completed. Moreover, excess exogenous alpha-SNAP that blocks SNARE function prevented membrane fusion and caused accumulation of non-flattened vesicles on the chromatin surface. Under these conditions, the nucleoporins Nup107 and gp210 were fully recruited, whereas assembly of FxFG-repeat-containing nucleoporins was blocked. Together, we define NSF- and SNARE-mediated membrane fusion events as essential steps during NE formation downstream of Nup107 recruitment, and upstream of membrane flattening and completion of NPC assembly.

  20. Phenotypic variations in osmotic lysis of Sahel goat erythrocytes in non-ionic glucose media.

    Science.gov (United States)

    Igbokwe, Nanacha Afifi; Igbokwe, Ikechukwu Onyebuchi

    2016-03-01

    Erythrocyte osmotic lysis in deionised glucose media is regulated by glucose influx, cation efflux, and changes in cell volume after water diffusion. Transmembrane fluxes may be affected by varied expression of glucose transporter protein and susceptibility of membrane proteins to glucose-induced glycosylation and oxidation in various physiologic states. Variations in haemolysis of Sahel goat erythrocytes after incubation in hyposmotic non-ionic glucose media, associated with sex, age, late pregnancy, and lactation, were investigated. The osmotic fragility curve in glucose media was sigmoidal with erythrocytes from goats in late pregnancy (PRE) or lactation (LAC) or from kid (KGT) or middle-aged (MGT) goats. Non-sigmoidal phenotype occurred in yearlings (YGT) and old (OGT) goats. The composite fragility phenotype for males and non-pregnant dry (NPD) females was non-sigmoidal. Erythrocytes with non-sigmoidal curves were more stable than those with sigmoidal curves because of inflectional shift of the curve to the left. Erythrocytes tended to be more fragile with male than female sex, KGT and MGT than YGT and OGT, and LAC and PRE than NPD. Thus, sex, age, pregnancy, and lactation affected the haemolytic pattern of goat erythrocytes in glucose media. The physiologic state of the goat affected the in vitro interaction of glucose with erythrocytes, causing variations in osmotic stability with variants of fragility phenotype. Variations in the effect of high extracellular glucose concentrations on the functions of membrane-associated glucose transporter, aquaporins, and the cation cotransporter were presumed to be relevant in regulating the physical properties of goat erythrocytes under osmotic stress.

  1. Tumor lysis syndrome in a patient with metastatic colon cancer after treatment with oxaliplatin and 5-Fu

    Directory of Open Access Journals (Sweden)

    Ruo-Han Tseng

    2016-12-01

    Full Text Available Tumor lysis syndrome in solid tumors is a rare occurrence, with a poor prognosis. We present the case of a patient of recurrent colon cancer who received chemotherapy with FOLFOX regimen (lencovorin, fluorouracil, and oxaliplatin with subsequent tumor lysis. We present a recurrent rectal cancer patient suffered from tumor lysis syndrome after salvage FOLFOX regimen. After treat with CVVH with improved conscious status. In this case report, we had review the tumor lysis in solid tumor.

  2. Coiled-coils on lipid membranes : a new perspective on membrane fusion

    NARCIS (Netherlands)

    Rabe, Martin

    2014-01-01

    For decades a large amount of research has dealt with membrane interactions of peptides and proteins as well as peptide-peptide interactions to understand the mechanisms of essential biological processes such as protein-driven vesicle budding and fission, cell penetration and lysis by peptides, and

  3. A molecular model for membrane fusion based on solution studies of an amphiphilic peptide from HIV gp41.

    OpenAIRE

    Fujii, G.; Horvath, S.; Woodward, S.; Eiserling, F.; Eisenberg, D.

    1992-01-01

    The mechanism of protein-mediated membrane fusion and lysis has been investigated by solution-state studies of the effects of peptides on liposomes. A peptide (SI) corresponding to a highly amphiphilic C-terminal segment from the envelope protein (gp41) of the human immunodeficiency virus (HIV) was synthesized and tested for its ability to cause lipid membranes to fuse together (fusion) or to break open (lysis). These effects were compared to those produced by the lytic and fusogenic peptide ...

  4. Enzyme-mediated Nutrient Regeneration Following Lysis of Synechococcus WH7803

    Science.gov (United States)

    Mine, A. H.; Coleman, M.; Colman, A. S.

    2016-02-01

    Phosphate availability plays a pivotal role in limiting primary production in large regions of the oceans. In order to meet their metabolic needs, microbes use a variety of strategies to overcome phosphate stress. Expression of enzymes such as alkaline phosphatase (APase) allows cells to hydrolyze and use certain ambient dissolved organic phosphorus (DOP) compounds to meet their P demand. Cell lysis releases a range of nutrient forms and enzymes into the ambient environment and is an essential component of the microbial loop. Yet very few studies have attempted to characterize both the immediate and sustained nutrient remineralization linked to the milieu of organophosphorus compounds and enzymatic activity in lysate. We conducted experiments using Synechococcus WH7803 grown under nutrient replete and starved conditions to quantify the release of phosphate during viral lysis and lysis by lysozyme treatment. Dissolved inorganic and organic phosphorus concentrations and APase activity were monitored over time following lysis. We observed a significant initial release of orthophosphate that accompanies lysis. Following lysis, phosphate concentrations continue to rise for a period of hours to days as organophosphorus compounds continue to hydrolyze. Our observations suggest this is due to a combination of direct hydrolysis of DOP released during lysis, solubilization of POP followed by hydrolysis, and possibly polyphosphate decomposition. Size fractionated enzymatic assays suggest cellular debris associated enzymes and dissolved fractions are both important in DOP hydrolysis in the viral lysate, whereas particle associated APase activity dominates in the lysozyme treatments. Moreover, nutrient status prior to lysis has important controls on the initial nutrient release and subsequent regenerative flux. These findings underscore the significance of lysis and subsequent enzyme-mediated hydrolysis in nutrient regeneration and biogeochemical dynamics in marine ecosystems.

  5. UTILIZATION OF MEMBRANE MICROFILTRATION IN PREPARATION OF HYDROLYZED VEGETABLE PROTEIN FROM FERMENTED RED BEAN (Phaseolus vulgaris L. EXTRACT AS FORTIFICATION AGENT

    Directory of Open Access Journals (Sweden)

    Sri Moerniati

    2010-06-01

    Full Text Available Preparation of Hydrolyzed Vegetable Protein (HVP as savory flavor from fermented red bean broth through stirred membrane cell using micro filtration membrane with pore size of 0.45 µm was performed to get fortified agent utilized in preparation of beans sauce. The objective of this work was to study an effect of pressure and kind of red bean broth extract on content of total protein, soluble protein and dry solid in the retentate and permeate as hydrolyzed vegetable protein used for fortified agent of red bean sauces. Preparation process of hydrolyzed vegetable protein was done using fixed rotary speed of 400 rpm, pressure of 20, 25 and 30 psi at room temperature. To investigate the effect of pressure on this separation, the feed were red bean broth extract fermented for 6, 8, 10 and 12 weeks, respectively. Fermentation process were conducted using salt fermentation with inoculum of Rhizopus-C1, salt and red bean ratios of 30:10:60%. The analysis of flux and contents of total protein, dissolved protein and dry solid in the retentate and permeate was carried out, and the result of experiment showed that interaction of Red bean broth extract with 6, 8, 10 and 12 weeks of fermentation and operation condition of microfiltration membrane separation tends to affect on flux and content of total protein, dissolved protein and dry solid in retentate and permeate. Red bean broth extract for 6 weeks fermentation resulted higher protein content in permeate as hydrolyzed vegetable protein than in retentate. Permeate at pressure of 25 psi gives flux value of 0.0217 mL/cm2.minute and contents of total protein of 1.31 %, dissolved protein of 6.9 mg/g, and dry solid of 2.6%, while retentate as hydrolyzed vegetable protein or fortified agent indicate contents of total protein of 1.52%, dissolved protein of 4.15 mg/g, and dry solid of 3.64%. It was found that micro filtration process was able to increase dissolved protein content of about 3 times.   Keywords

  6. [Acute renal failure in patients with tumour lysis sindrome].

    Science.gov (United States)

    Poskurica, Mileta; Petrović, Dejan; Poskurica, Mina

    2016-01-01

    `Hematologic malignancies (leukemia, lymphoma, multiple myeloma, et al.), as well as solid tumours (renal, liver, lung, ovarian, etc.), can lead to acute or chronic renal failure.The most common clinical manifestation is acute renal failure within the tumour lysis syndrome (TLS). It is characterized by specific laboratory and clinical criteria in order to prove that kidney disorders result from cytolysis of tumour cells after chemotherapy regimen given, although on significantly fewer occasions it is likely to occur spontaneously or after radiotherapy. Essentially, failure is the disorder of functionally conserved kidney or of kidney with varying degrees of renal insufficiency, which render the kidney impaired and unable to effectively eliminate the end products of massive cytolysis and to correct the resulting disorders: hyperuricemia, hyperkalemia, hypocalcaemia, hyperphosphatemia, and others. The risk of TLS depends on tumour size, proliferative potential of malignant cells, renal function and the presence of accompanying diseases and disorders. Hydration providing adequate diuresis and administration of urinary suppressants (allopurinol, febuxostat) significantly reduce the risk of developing TLS. If prevention of renal impairment isn't possible, the treatment should be supplemented with hemodynamic monitoring and pharmacological support, with the possible application of recombinant urate-oxidase enzyme (rasburicase). Depending on the severity of azotemia and hydroelectrolytic disorders, application of some of the methods of renal replacement therapy may be considered.

  7. Acute renal failure in patients with tumour lysis sindrome

    Directory of Open Access Journals (Sweden)

    Poskurica Mileta

    2016-01-01

    Full Text Available Hematologic malignancies (leukemia, lymphoma, multiple myeloma, et al., as well as solid tumours (renal, liver, lung, ovarian, etc., can lead to acute or chronic renal failure. The most common clinical manifestation is acute renal failure within the tumour lysis syndrome (TLS. It is characterized by specific laboratory and clinical criteria in order to prove that kidney disorders result from cytolysis of tumour cells after chemotherapy regimen given, although on significantly fewer occasions it is likely to occur spontaneously or after radiotherapy. Essentially, failure is the disorder of functionally conserved kidney or of kidney with varying degrees of renal insufficiency, which render the kidney impaired and unable to effectively eliminate the end products of massive cytolysis and to correct the resulting disorders: hyperuricemia, hyperkalemia, hypocalcaemia, hyperphosphatemia, and others. The risk of TLS depends on tumour size, proliferative potential of malignant cells, renal function and the presence of accompanying diseases and disorders. Hydration providing adequate diuresis and administration of urinary suppressants (allopurinol, febuxostat significantly reduce the risk of developing TLS. If prevention of renal impairment isn’t possible, the treatment should be supplemented with hemodynamic monitoring and pharmacological support, with the possible application of recombinant urate-oxidase enzyme (rasburicase. Depending on the severity of azotemia and hydroelectrolytic disorders, application of some of the methods of renal replacement therapy may be considered.

  8. Evaluation of conventional castaneda and lysis centrifugation blood culture techniques for diagnosis of human brucellosis.

    Science.gov (United States)

    Mantur, Basappa G; Mangalgi, Smita S

    2004-09-01

    We investigated the role of the lysis centrifugation blood culture technique over the conventional Castaneda technique for the diagnosis of human brucellosis. The lysis centrifugation technique has been found to be more sensitive in both acute (20% higher sensitivity; P centrifugation was in the mean detection time, which was only 2.4 days in acute and 2.7 days in chronic cases, with 103 out of 110 (93.6%) and 17 out of 20 (85%) cultures from acute and chronic brucellosis, respectively, detected before the conventional culture was positive. Our results confirmed the potential usefulness of the lysis technique in diagnosis and institution of appropriate antibiotic therapy.

  9. Spatially selecting a single cell for lysis using light-induced electric fields.

    Science.gov (United States)

    Witte, Christian; Kremer, Clemens; Chanasakulniyom, Mayuree; Reboud, Julien; Wilson, Rab; Cooper, Jonathan M; Neale, Steven L

    2014-08-13

    An optoelectronic tweezing (OET) device, within an integrated microfluidic channel, is used to precisely select single cells for lysis among dense populations. Cells to be lysed are exposed to higher electrical fields than their neighbours by illuminating a photoconductive film underneath them. Using beam spot sizes as low as 2.5 μm, 100% lysis efficiency is reached in <1 min allowing the targeted lysis of cells. © 2014 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Electro-driven extraction of polar compounds using agarose gel as a new membrane: Determination of amino acids in fruit juice and human plasma samples.

    Science.gov (United States)

    Sedehi, Samira; Tabani, Hadi; Nojavan, Saeed

    2018-03-01

    In this work, polypropylene hollow fiber was replaced by agarose gel in conventional electro membrane extraction (EME) to develop a novel approach. The proposed EME method was then employed to extract two amino acids (tyrosine and phenylalanine) as model polar analytes, followed by HPLC-UV. The method showed acceptable results under optimized conditions. This green methodology outperformed conventional EME, and required neither organic solvents nor carriers. The effective parameters such as the pH values of the acceptor and the donor solutions, the thickness and pH of the gel, the extraction voltage, the stirring rate, and the extraction time were optimized. Under the optimized conditions (acceptor solution pH: 1.5; donor solution pH: 2.5; agarose gel thickness: 7mm; agarose gel pH: 1.5; stirring rate of the sample solution: 1000rpm; extraction potential: 40V; and extraction time: 15min), the limits of detection and quantification were 7.5ngmL -1 and 25ngmL -1 , respectively. The extraction recoveries were between 56.6% and 85.0%, and the calibration curves were linear with correlation coefficients above 0.996 over a concentration range of 25.0-1000.0ngmL -1 for both amino acids. The intra- and inter-day precisions were in the range of 5.5-12.5%, and relative errors were smaller than 12.0%. Finally, the optimized method was successfully applied to preconcentrate, clean up, and quantify amino acids in watermelon and grapefruit juices as well as a plasma sample, and acceptable relative recoveries in the range of 53.9-84.0% were obtained. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Study of the extraction and the purification of americium and trivalent actinides contained in effluents with supported liquid membranes

    International Nuclear Information System (INIS)

    Guillou, P.

    1990-12-01

    The supported liquid membrane technique is studied and developed for americium recovery from uranium or plutonium matrices and decontamination of liquid radioactive wastes. First tests on uranium-nickel solutions with a flat membrane showed the easiness of the operation and the efficiency of the process. Acid-resistant (10 N), interchangeable elements with hollow fibers, are developed and also a computerized automatic device. The different tests on americium solutions demonstrate the feasibility and the reliability of the system. Influence of various parameters on transfer kinetics is investigated

  12. Simultaneous extraction and determination of trace amounts of diclofenac from whole blood using supported liquid membrane microextraction and fast fourier transform voltammetry.

    Science.gov (United States)

    Mofidi, Zahra; Norouzi, Parviz; Sajadian, Masumeh; Ganjali, Mohammad Reza

    2018-01-19

    A novel, simple and inexpensive analytical technique based on flat sheet supported liquid membrane microextraction coupled with fast Fourier transform stripping cyclic voltammetry on a reduced graphene oxide carbon paste electrode was used for the extraction and online determination of diclofenac in whole blood. First, diclofenac was extracted from blood samples using a polytetrafluoroethylene membrane impregnated with 1-octanol and then into an acceptor solution, subsequently it was oxidized on a carbon paste electrode modified with reduced graphene oxide nano-sheets. The optimal values of the key parameters influencing the method were; scan rate = 6 V s -1 , stripping potential = 200 mV, stripping time = 5 s, pH of the sample solution = 5, pH of the acceptor solution = 7, and extraction time = 240 min. The calibration curves were plotted for the whole blood samples and the method was found to have a good linearity within the range of 1-25 μg mL -1 with a determination coefficient of 0.99. The limits of detection and quantification were 0.1 and 1.0 μg mL -1 , respectively. Using this coupled method, the extraction and determination were merged into one step. Accordingly, the speed of detection for sensitive determination of diclofenac in complex samples like blood increased considerably. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. A rapid and low-cost DNA extraction method for isolating ...

    African Journals Online (AJOL)

    user

    2011-02-21

    Feb 21, 2011 ... The method reported by Mieta et al. (2010) was used for this section with the following modifications. DNA extraction was performed using 200 µl stool sample suspension as template. The lysis buffer was pre-mixed with the celite and the lysis step was performed at 70°C. The DNA was eluted with 400 µl ...

  14. Evaluation of antibacterial properties on polysulfone composite membranes using synthesized biogenic silver nanoparticles with Ulva compressa (L.) Kütz. and Cladophora glomerata (L.) Kütz. extracts.

    Science.gov (United States)

    Minhas, Fozia T; Arslan, Gulsin; Gubbuk, I Hilal; Akkoz, Cengiz; Ozturk, Betul Yılmaz; Asıkkutlu, Baran; Arslan, Ugur; Ersoz, Mustafa

    2018-02-01

    Polysulfone (PS) composite membrane using green synthesized biogenic silver nanoparticles (Ag-NPs) with Ulva compressa (L.) Kütz. and Cladophora glomerata (L.) Kütz. extract were prepared by spin coating technique and are tested for antimicrobial activity using a direct contact test for the first time. Initially green synthesis of Ag-NPs was accomplished utilizing green macro algae i.e. U. compressa (L.) Kütz. and C. glomerata (L.) Kütz. by the reduction of AgNO 3 . The Ag-NPs/PS composite membranes from both algae revealed outstanding antimicrobial activity against all bacteria i.e. K. pneumonia, P. aeruginasa, E. coli, E. faecium and S. aureus. Bacterial growth was monitored for 17h with a temperature controlled microplate spectrophotometer. The kinetics of the outgrowth in each well were recorded continuously at 630nm every 60min. Thus present work remarkably offers a feasible, cheap and efficient alternative for making Ag-NPs and their utilization as antimicrobial agent on the PS composite membrane. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Mycobacterium tuberculosis bacteremia detected by the Isolator lysis-centrifugation blood culture system.

    OpenAIRE

    Kiehn, T E; Gold, J W; Brannon, P; Timberger, R J; Armstrong, D

    1985-01-01

    Mycobacterium tuberculosis was detected by the Isolator lysis-centrifugation blood culture system from the blood of a patient with tuberculosis of the breast. The organism also grew on conventional laboratory media inoculated with pleural fluid from the patient.

  16. A novel method for determination and quantification of 4-methyloctanoic and 4-methylnonanoic acids in mutton by hollow fiber supported liquid membrane extraction coupled with gas chromatography.

    Science.gov (United States)

    Chen, Haigui; Wang, Yunfan; Jiang, Houyang; Zhao, Guohua

    2012-12-01

    4-Methyloctanoic acid (MOA) and 4-methylnonanoic acid (MNA) are the main compounds responsible for "sweaty" odor of mutton. A novel method for their determination has been developed and validated. Hollow fiber supported liquid membrane (HF-SLM) was applied to selectively extract MOA and MNA prior to gas chromatography (GC) analysis. For HF-SLM, the donor outside the fiber was the acidified supernatant (pH 4) from aqueous mutton slurry. Liquid membrane was 5% tri-n-octylphoshphine oxide in di-n-hexyl ether and 0.3M NaOH aqueous solution filled in the lumen of the fiber was used as the acceptor. The extraction last for 4h. After acidification with HCl, the acceptor was directly analyzed by GC. Importantly, HF-SLM provided high enrichment factors for MOA (133) and MNA (116). The method developed had low detection limits of 0.0007-0.0015 mg/kg, good linearity (R²>0.9956), reasonable recovery (88.54-122.13%), satisfactory intra-assay (7.83-9.73%) and inter-assay (15.68-16.14%) precision. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Selective and simultaneous determination of trace bisphenol A and tebuconazole in vegetable and juice samples by membrane-based molecularly imprinted solid-phase extraction and HPLC.

    Science.gov (United States)

    Wu, Ya-Ting; Zhang, Yan-Hong; Zhang, Meng; Liu, Fei; Wan, Ying-Chun; Huang, Zheng; Ye, Lei; Zhou, Qi; Shi, Yun; Lu, Bin

    2014-12-01

    Nanofibrous molecularly imprinted membranes (nano-MIMs) with multi-analyte selectivity were prepared by encapsulating two types of molecularly imprinted polymer nanoparticles (MIP-NPs) into electrospun polyvinyl alcohol nanofibers. The obtained nano-MIMs maintained high molecular selectivity offered by each of the MIP-NPs. Nano-MIM embedding BPA-imprinted nanoparticles and TBZ-imprinted nanoparticles together showed the highest binding selectivity for acid bisphenol A (BPA) and basic tebuconazole (TBZ). This nano-MIM was used as affinity material of membrane-based molecularly imprinted solid-phase extraction (m-MISPE) to extract trace BPA and TBZ in vegetables and juices simultaneously. The recoveries of BPA and TBZ from different samples were higher than 70.33% with RSDs lower than 9.57%. m-MISPE gave better HPLC separation efficiencies and higher recoveries than conventional SPE based on C18/SCX. Multi-analyte selective m-MISPE combined with HPLC realized selective and simultaneous determination of several trace analytes with opposite charges/polarities in different food samples. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. In-line coupling of supported liquid membrane extraction to capillary electrophoresis for simultaneous analysis of basic and acidic drugs in urine.

    Science.gov (United States)

    Pantůčková, Pavla; Kubáň, Pavel

    2017-10-13

    Simultaneous extraction of basic and acidic drugs across thin supported liquid membrane (SLM) and direct injection of the extracted drugs from SLM surface into capillary electrophoresis (CE) were demonstrated. A microextraction device compatible with injection system of commercial CE instrument was filled with 20μL of sample and 10μL of acceptor solution, which were interspaced by the SLM impregnated with 5μL of organic solvent. Extractions of three basic drugs (nortriptyline, haloperidol and loperamide) and two acidic drugs (ketoprofen and naproxen) were achieved at optimized conditions including 1-ethyl-2-nitrobenzene as SLM solvent, natural pH of sample solution, 2.5mM NaOH acceptor solution and 30min extraction time. The extracted drugs were directly injected into CE for separation and quantification in a background electrolyte solution consisting of 30mM ammonium acetate adjusted to pH 4.2 with acetic acid. The entire analytical procedure including drugs extraction, injection, separation and quantification was automated in the CE instrument and the only manual procedures were SLM impregnation and filling the microextraction device with sample and acceptor solutions. The analytical method was suitable for simultaneous determination of basic and acidic drugs in undiluted human urine samples and was used for direct determination of naproxen in urine after oral administration of Nalgesin S tablet. Efficient elimination of sample matrix and selective transfer of basic and acidic drugs were achieved and the hyphenated SLM-CE method was characterized by repeatability of peak areas ranging from 3.7 to 13.4%, linear relationship between peak areas and concentrations (r 2 =0.994-0.999) and limits of detection between 0.05 and 1.5μg/mL. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. A system for field gas-extraction of 85Kr, 39Ar and 81Kr using SuperPhobic membrane contactors

    Science.gov (United States)

    Burk, L.; Suckow, A.; Cook, P.; Mathouchanh, E.

    2013-12-01

    Radioactive noble gas isotopes are established tools for assessing groundwater movement and transport processes on time scales of decades (85Kr), centuries (39Ar) and many millenia (81Kr). While the atomic trap trace analysis (ATTA) technology promises small sample sizes for these isotopes, field gas extraction will remain the method of choice for several years to come. Recently CSIRO obtained decommissioned radiocarbon gas proportional counters and targets to use them for 85Kr. We aim for a sample size of 50μL Kr corresponding to the gas extracted from 500-1000L water. Flinders University and CSIRO have developed a field-deployable extraction system for large volume gas-extraction in the field. It uses two membrane contactors (MEMBRANA SuperPhobic 4x13) allowing flow rates of up to 50L/min in serial mode. Switching to parallel flow through both contactors is possible, allowing even higher water flow rates. The system automatically logs water temperature, water pressure, water flow rate, gas pressure of the sample, vacuum pressure at the contactor and all valve states, using an Endress + Hauser RSG40 Memograph M. The use of SuperPhobic contactors results in ten times less water in the gas fraction than reported for earlier systems. With the two contactors in serial configuration, gas extraction efficiencies, determined for O2, N2 and Ar, are better than 95% at 5L/min water flow. They are still above 80% for flow rates up to 20L/min in parallel configuration for O2, N2 and Ar. No measurable isotopic fractionation of the target isotope ratios of argon and krypton is to be expected at these high extraction efficiencies.

  20. Application of enzyme-linked immunosorbent assay for measurement of polychlorinated biphenyls from hydrophobic solutions: Extracts of fish and dialysates of semipermeable membrane devices: Chapter 26

    Science.gov (United States)

    Zajicek, James L.; Tillitt, Donald E.; Huckins, James N.; Petty, Jimmie D.; Potts, Michael E.; Nardone, David A.

    1996-01-01

    Determination of PCBs in biological tissue extracts by enzyme-linked immunosorbent assays (ELISAs) can be problematic, since the hydrophobic solvents used for their extraction and isolation from interfering biochemicals have limited compatibility with the polar solvents (e.g. methanol/water) and the immunochemical reagents used in ELISA. Our studies of these solvent effects indicate that significant errors can occur when microliter volumes of PCB containing extracts, in hydrophobic solvents, are diluted directly into methanol/water diluents. Errors include low recovery and excess variability among sub-samples taken from the same sample dilution. These errors are associated with inhomogeneity of the dilution, which is readily visualized by the use of a hydrophobic dye, Solvent Blue 35. Solvent Blue 35 is also used to visualize the evaporative removal of hydrophobic solvent and the dissolution of the resulting PCB/dye residue by pure methanol and 50% (v/v) methanol/water, typical ELISA diluents. Evaporative removal of isooctane by an ambient temperature nitrogen purge with subsequent dissolution in 100% methanol gives near quantitative recovery of model PCB congeners. We also compare concentrations of total PCBs from ELISA (ePCB) to their corresponding concentrations determined from capillary gas chromatography (GC) in selected fish sample extracts and dialysates of semipermeable membrane device (SPMD) passive samplers using an optimized solvent exchange procedure. Based on Aroclor 1254 calibrations, ePCBs (ng/mL) determined in fish extracts are positively correlated with total PCB concentrations (ng/mL) determined by GC: ePCB = 1.16 * total-cPCB - 5.92. Measured ePCBs (ng/3 SPMDs) were also positively correlated (r2 = 0.999) with PCB totals (ng/3 SPMDs) measured by GC for dialysates of SPMDs: ePCB = 1.52 * total PCB - 212. Therefore, this ELISA system for PCBs can be a rapid alternative to traditional GC analyses for determination of PCBs in extracts of biota or in

  1. Solid-phase extraction of cobalt(II) from lithium chloride solutions using a poly(vinyl chloride)-based polymer inclusion membrane with Aliquat 336 as the carrier.

    Science.gov (United States)

    Kagaya, Shigehiro; Cattrall, Robert W; Kolev, Spas D

    2011-01-01

    The extraction of cobalt(II) from solutions containing various concentrations of lithium chloride, hydrochloric acid, and mixtures of lithium chloride plus hydrochloric acid is reported using a poly(vinyl chloride) (PVC)-based polymer inclusion membrane (PIM) containing 40% (w/w) Aliquat 336 as a carrier. The extraction from lithium chloride solutions and mixtures with hydrochloric acid is shown to be more effective than extraction from hydrochloric acid solutions alone. The solution concentrations giving the highest amounts of extraction are 7 mol L(-1) for lithium chloride and 8 mol L(-1) lithium chloride plus 1 mol L(-1) hydrochloric acid for mixed solutions. Cobalt(II) is easily stripped from the membrane using deionized water. The cobalt(II) species extracted into the membrane are CoCl(4)(2-) for lithium chloride solutions and HCoCl(4)(-) for mixed solutions; these form ion-pairs with Aliquat 336. It is also shown that both lithium chloride and hydrochloric acid are extracted by the PIM and suppress the extraction of cobalt(II) by forming ion-pairs in the membrane (i.e. R(3)MeN(+)·HCl(2)(-) for hydrochloric acid and R(3)MeN(+)·LiCl(2)(-) for lithium chloride). 2011 © The Japan Society for Analytical Chemistry

  2. Susceptibility of pathogenic and nonpathogenic Naegleria spp. to complement-mediated lysis.

    OpenAIRE

    Whiteman, L Y; Marciano-Cabral, F

    1987-01-01

    The susceptibility of four species of Naegleria amoebae to complement-mediated lysis was determined. The amoebicidal activity of normal human serum (NHS) and normal guinea pig serum (NGPS) for Naegleria amoebae was measured by an in vitro cytotoxicity assay. Release of radioactivity from amoebae labeled with [3H]uridine and visual observation with a compound microscope were used as indices of lysis. Highly pathogenic mouse-passaged N. fowleri was less susceptible to the lytic effects of NHS a...

  3. Low-Cost Energy-Efficient 3-D Nano-Spikes-Based Electric Cell Lysis Chips

    KAUST Repository

    Riaz, Kashif

    2017-05-04

    Electric cell lysis (ECL) is a promising technique to be integrated with portable lab-on-a-chip without lysing agent due to its simplicity and fast processing. ECL is usually limited by the requirements of high power/voltage and costly fabrication. In this paper, we present low-cost 3-D nano-spikes-based ECL (NSP-ECL) chips for efficient cell lysis at low power consumption. Highly ordered High-Aspect-Ratio (HAR). NSP arrays with controllable dimensions were fabricated on commercial aluminum foils through scalable and electrochemical anodization and etching. The optimized multiple pulse protocols with minimized undesirable electrochemical reactions (gas and bubble generation), common on micro parallel-plate ECL chips. Due to the scalability of fabrication process, 3-D NSPs were fabricated on small chips as well as on 4-in wafers. Phase diagram was constructed by defining critical electric field to induce cell lysis and for cell lysis saturation Esat to define non-ECL and ECL regions for different pulse parameters. NSP-ECL chips have achieved excellent cell lysis efficiencies ηlysis (ca 100%) at low applied voltages (2 V), 2~3 orders of magnitude lower than that of conventional systems. The energy consumption of NSP-ECL chips was 0.5-2 mJ/mL, 3~9 orders of magnitude lower as compared with the other methods (5J/mL-540kJ/mL). [2016-0305

  4. The effects of hydration and divalent cations on lamellar-nonlamellar phase transitions in membranes and total lipid extracts from Acholeplasma laidlawii A-EF22 - a 2H NMR study

    International Nuclear Information System (INIS)

    Niemi, A.E.; Andersson, A.S.; Rilfors, L.; Lindblom, G.; Arvidson, G.

    1997-01-01

    Acholeplasma laidlawii strain A-EF22 was grown in a medium supplemented with 75 μm α-deuterated palmitic acid (16:0-d 2 ) and 75 μm α-deuterated oleic acid (18:1c-d 2 ), or with 150 μm 18:1c-d 2 . The fatty acids were incorporated into the membrane lipids and 2 H NMR spectra were recorded from intact membranes, total lipid extracts, and the combined glucolipid and neutral lipid fractions of a total lipid extract. The lipids in intact membranes form a bilayer structure up to at least 70 C. The same result was obtained with membranes digested with pronase, which removes a large fraction of the membrane proteins. A reversed hexagonal liquid crystalline (H II ) phase was formed below 70 C by the total lipid extracts hydrated with 20 and 30% (w/w) water; in the presence of 40% (w/w) water only one of the extracts formed an H II phase below 70 C. The H II phase was formed at higher temperatures with an increasing water content. However, only a lamellar liquid crystalline (L α ) phase was formed up to 70 C by the total lipid extracts when the water concentrations were 50% (w/w) or higher. The temperature (T LH ) for the L α to H II phase transition in the combined glucolipid and neutral lipid fractions was only 2-3 C lower than for the total lipids, and the phospholipids thus have a very modest influence on the T LH value. Physiologically relevant concentrations of Ca 2+ and Mg 2+ ions did not affect the phase equilibria of total lipid extracts significantly. It is concluded from comparison with published data that the membrane lipids of the cell wall-less bacterium A. laidlawii have a smaller tendency to form reversed nonlamellar phases than the membrane lipids of three bacterial species surrounded by a cell wall. (orig.)

  5. Fractalkine expression induces endothelial progenitor cell lysis by natural killer cells.

    Directory of Open Access Journals (Sweden)

    Dilyana Todorova

    Full Text Available BACKGROUND: Circulating CD34(+ cells, a population that includes endothelial progenitors, participate in the maintenance of endothelial integrity. Better understanding of the mechanisms that regulate their survival is crucial to improve their regenerative activity in cardiovascular and renal diseases. Chemokine-receptor cross talk is critical in regulating cell homeostasis. We hypothesized that cell surface expression of the chemokine fractalkine (FKN could target progenitor cell injury by Natural Killer (NK cells, thereby limiting their availability for vascular repair. METHODOLOGY/PRINCIPAL FINDINGS: We show that CD34(+-derived Endothelial Colony Forming Cells (ECFC can express FKN in response to TNF-α and IFN-γ inflammatory cytokines and that FKN expression by ECFC stimulates NK cell adhesion, NK cell-mediated ECFC lysis and microparticles release in vitro. The specific involvement of membrane FKN in these processes was demonstrated using FKN-transfected ECFC and anti-FKN blocking antibody. FKN expression was also evidenced on circulating CD34(+ progenitor cells and was detected at higher frequency in kidney transplant recipients, when compared to healthy controls. The proportion of CD34(+ cells expressing FKN was identified as an independent variable inversely correlated to CD34(+ progenitor cell count. We further showed that treatment of CD34(+ circulating cells isolated from adult blood donors with transplant serum or TNF-α/IFN-γ can induce FKN expression. CONCLUSIONS: Our data highlights a novel mechanism by which FKN expression on CD34(+ progenitor cells may target their NK cell mediated killing and participate to their immune depletion in transplant recipients. Considering the numerous diseased contexts shown to promote FKN expression, our data identify FKN as a hallmark of altered progenitor cell homeostasis with potential implications in better evaluation of vascular repair in patients.

  6. Membrane contactor applications

    NARCIS (Netherlands)

    Klaassen, R.; Feron, P.H.M.; Jansen, A.

    2008-01-01

    In a membrane contactor the membrane separation is completely integrated with an extraction or absorption operation in order to exploit the benefits of both technologies fully. Membrane contactor applications that have been developed can be found in both water and gas treatment. Several recently

  7. Soil pretreatment and fast cell lysis for direct polymerase chain reaction from forest soils for terminal restriction fragment length polymorphism analysis of fungal communities

    Directory of Open Access Journals (Sweden)

    Fei Cheng

    Full Text Available Abstract Humic substances in soil DNA samples can influence the assessment of microbial diversity and community composition. Using multiple steps during or after cell lysis adds expenses, is time-consuming, and causes DNA loss. A pretreatment of soil samples and a single step DNA extraction may improve experimental results. In order to optimize a protocol for obtaining high purity DNA from soil microbiota, five prewashing agents were compared in terms of their efficiency and effectiveness in removing soil contaminants. Residual contaminants were precipitated by adding 0.6 mL of 0.5 M CaCl2. Four cell lysis methods were applied to test their compatibility with the pretreatment (prewashing + Ca2+ flocculation and to ultimately identify the optimal cell lysis method for analyzing fungal communities in forest soils. The results showed that pretreatment with TNP + Triton X-100 + skim milk (100 mM Tris, 100 mM Na4P2O7, 1% polyvinylpyrrolidone, 100 mM NaCl, 0.05% Triton X-100, 4% skim milk, pH 10.0 removed most soil humic contaminants. When the pretreatment was combined with Ca2+ flocculation, the purity of all soil DNA samples was further improved. DNA samples obtained by the fast glass bead-beating method (MethodFGB had the highest purity. The resulting DNA was successfully used, without further purification steps, as a template for polymerase chain reaction targeting fungal internal transcribed spacer regions. The results obtained by terminal restriction fragment length polymorphism analysis indicated that the MethodFGB revealed greater fungal diversity and more distinctive community structure compared with the other methods tested. Our study provides a protocol for fungal cell lysis in soil, which is fast, convenient, and effective for analyzing fungal communities in forest soils.

  8. Herbal extract of Artemisia vulgaris (mugwort) induces antitumor effects in HCT-15 human colon cancer cells via autophagy induction, cell migration suppression and loss of mitochondrial membrane potential.

    Science.gov (United States)

    Lian, Guanghui; Li, Fujun; Yin, Yani; Chen, Linlin; Yang, Junwen

    2018-01-01

    Artemisia vulgaris (A.vulgaris) belonging to family Compositae, commonly known as mugwort, has been used as a medicinal herb in Chinese traditional medicine for treatment of diseases. Studies have reported a diversity of activities for this plant which include antiseptic, antispasmodic, antigastric, anticancer and nervous system diseases. However, the anticancer activity of A.vulgaris in HCT-15 human colon cancer cells has not been scientifically validated. Therefore the present study aimed at evaluating the anticancer activity of methanolic extract of A.vulgaris against HCT-15 human colon cancer cell line. Cell cytotoxicity effects of the extract were evaluated by MTT cell viability assay, while clonogenic assay assessed the effects on cancer cell colony formation. Effects on reactive oxygen species (ROS) production and mitochondrial membrane potential (MMP) were evaluated by flow cytometry. In vitro wound healing assay was used to evaluate the effects on cell migration. To confirm autophagy, we evaluated the expression of several autophagy-associated proteins using Western blot assay. Results indicated that the methanolic extract of A.vulgaris exhibited an IC50 value of 50 μg/ml and exerted its cytotoxic effects in a dose-dependent manner. Moreover, it was observed that the extract inhibits colony formation and induces autophagy dose-dependently. The underlying mechanism for the induction of autophagy was found to be ROS-mediated MMP and significant inhibition of cell migration potential of colon cancer cells at the IC50 was observed. These results strongly stress that the methanolic extract may prove a source for the isolation of novel anticancer lead molecules for the management of colon cancer.

  9. Magnetite-doped eggshell membrane as a magnetic sorbent for extraction of aluminum(III) ions prior to their fluorometric determination

    International Nuclear Information System (INIS)

    Abdolmohammad-Zadeh, Hossein; Talleb, Zeynab

    2014-01-01

    We have explored the feasibility of using a magnetite-doped eggshell membrane as a magnetic solid phase extraction sorbent for the separation of aluminum ion from aqueous solutions. The sorbent was characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy. A fast, simple and non-expensive method was then developed for the determination of trace quantities of Al(III) in water and food samples by combining magnetic solid phase extraction with fluorometric quantitation via its highly fluorescent complex with 8-hydroxyquinoline. The effects of pH value, amount of sorbent, sample volume, elution conditions and interfering ions on extraction were optimized. Under optimum conditions, the calibration graph extends from 0.5 to 65.0 μg L −1 , the limit of detection is 0.2 μg L −1 , and the enrichment factor is 84. The method was validated by the successful analysis of a standard reference material (NIST SRM 1549; nonfat milk powder) and applied to the determination of Al(III) in several waters, black tea, tomato paste and cocoa powder samples. (author)

  10. Evaluation of cell lysis procedures and use of a micro fluidic system for an automated DNA-based cell identification in interplanetary missions

    Science.gov (United States)

    Hall, J. A.; Felnagle, E.; Fries, M.; Spearing, S.; Monaco, L.; Steele, A.

    2006-12-01

    A Modular Assay System for Solar System Exploration (MASSE) is being developed to include sample handling, pre-treatment, separation and analysis of biological target compounds by both DNA and protein microarrays. To better design sensitive and accurate initial upstream sample handling of the MASSE instrument, experiments investigating the sensitivity and potential extraction bias of commercially available DNA extraction kits between classes of environmentally relevant prokaryotes such as gram-negative bacteria ( Escherichia coli), gram-positive bacteria ( Bacillus megatarium), and Archaea ( Haloarcula marismortui) were performed. For extractions of both planktonic cultures and spiked Mars simulated regolith, FTA ® paper demonstrated the highest sensitivity, with detection as low as ˜1×10 1 cells and ˜3.3×10 2 cells, respectively. In addition to the highest sensitivity, custom modified application of FTA ® paper extraction protocol is the simplest in terms of incorporation into MASSE and displayed little bias in sensitivity with respect to prokaryotic cell type. The implementation of FTA paper for environmental microbiology investigations appears to be a viable and effective option potentially negating the need for other pre-concentration steps such as filtration and negating concerns regarding extraction efficiency of cells. In addition to investigations on useful technology for upstream sample handling in MASSE, we have also evaluated the potential for μTAS to be employed in the MASSE instrument by employing proprietary lab-on-a-chip development technology to investigate the potential for microfluidic cell lysis of different prokaryotic cells employing both chemical and biological lysis agents. Real-time bright-field microscopy and quantitative PMT detection indicated that that gram positive, gram negative and archaeal cells were effectively lyzed in a few seconds using the microfluidic chip protocol developed. This included employing a lysis buffer with

  11. Fine-tuning of electromembrane extraction selectivity using 18-crown-6 ethers as supported liquid membrane modifiers

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Kubáň, Pavel; Boček, Petr

    2014-01-01

    Roč. 35, č. 23 (2014), s. 3317-3320 ISSN 0173-0835 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : 18-Crown-6 ethers * electromembrane extraction * inorganic cations * selectivity modification Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.028, year: 2014

  12. Phellinus linteus polysaccharide extracts increase the mitochondrial membrane potential and cause apoptotic death of THP-1 monocytes

    NARCIS (Netherlands)

    Griensven, van L.J.L.D.; Verhoeven, H.A.

    2013-01-01

    Background: The differentiation resp. death of human monocytic THP-1 cells induced by polysaccharide extracts of the medicinal mushrooms Phellinus linteus, Agaricus bisporus and Agaricus brasiliensis have been studied. This study aims to identify leads for the causal effects of these mushroom

  13. Immobilization and release study of a red alga extract in hydrogel membranes; Estudo da incorporacao e liberacao de um extrato de algas vermelhas em membranas de hidrogel

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, Renata Hage

    2009-07-01

    In pharmaceutical technology hydrogel is the most used among the polymeric matrices due to its wide application and functionality, primarily in drug delivery system. In view of the large advance innovations in cosmetic products, both through the introduction of new active agents as the matrices used for its controlled release, the objective of this study was to evaluate the release and immobilization of a natural active agent, the Arct'Alg in hydrogel membranes to obtain a release device for cosmetics. Arct'Alg is an aqueous extract which has excellent anti-oxidant, lipolytic, anti-inflammatory and cytostimulant action. Study on mechanical and physical-chemical properties and biocompatibility in vitro of hydrogel membranes of poly(vinyl-2- pyrrolidone) (PVP) and poly(vinyl alcohol) (PVA) obtained by ionizing radiation crosslinking have been performed. The physical-chemical characterization of polymeric matrices was carried out by gel fraction and swelling tests and biocompatibility by in vitro test of cytotoxicity by using the technique of neutral red incorporation. In the gel fraction test, both the PVP and PVA hydrogel showed a high crosslinking degree. The PVP hydrogel showed a greater percentage of swelling in relation to PVA and the cytotoxicity test of the hydrogels showed non-toxicity effect. The cytostimulation property of Arct'Alg was verified by the cytostimulation test with rabbit skin cells, it was showed an increase at about 50% of the cells when in contact with 0,5% of active agent. The hydrogel membranes prepared with 3% of Arct'Alg were subjected to the release test in an incubator at 37 degree C and aliquots collected during the test were quantified by high performance liquid chromatography (HPLC). The results obtained in the kinetics of release showed that the PVP hydrogel membranes released about 50% of Arct'Alg incorporated and the PVA hydrogel membranes at about 30%. In the cytostimulation test of released Arct

  14. Simulation studies of ammonia removal from water in a membrane contactor under liquid-liquid extraction mode.

    Science.gov (United States)

    Mandowara, Amish; Bhattacharya, Prashant K

    2011-01-01

    Simulation studies were carried out, in an unsteady state, for the removal of ammonia from water via a membrane contactor. The contactor had an aqueous solution of NH(3) in the lumen and sulphuric acid in the shell side. The model equations were developed considering radial and axial diffusion and convection in the lumen. The partial differential equations were converted by the finite difference technique into a series of stiff ordinary differential equations w.r.t. time and solved using MATLAB. Excellent agreement was observed between the simulation results and experimental data (from the literature) for a contactor of 75 fibres. Excellent agreement was also observed between the simulation results and laboratory-generated data from a contactor containing 10,200 fibres. Our model is more suitable than the plug-flow model for designing the operation of the membrane contactor. The plug-flow model over-predicts the fractional removal of ammonia and was observed to be limited when designing longer contactors. Copyright © 2010 Elsevier Ltd. All rights reserved.

  15. Residue analysis of tetracyclines in milk by HPLC coupled with hollow fiber membranes-based dynamic liquid-liquid micro-extraction.

    Science.gov (United States)

    Xu, Hui; Mi, Hong-Yu; Guan, Ming-Ming; Shan, Hong-Yan; Fei, Qiang; Huan, Yan-Fu; Zhang, Zhi-Quan; Feng, Guo-Dong

    2017-10-01

    A novel hollow fiber membranes-based dynamic liquid-liquid micro-extraction (HF-DLLME) coupled with HPLC-UV detection has been developed for the residue analysis of tetracyclines in milk samples without deproteinization and degreasing. The influences of experimental parameters were investigated and optimized. The method showed a good performance. The limits of detection (LOD) are in the range of 0.95-3.6μg/L. The recoveries in spiked samples range from 92.38 to 107.3%. The relative standard deviations (RSDs) are lower than 8.66%. The advantages of this method are simple operation, high efficiency, absence of sample carryover and low cost. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Hollow Fiber Supported Liquid Membrane Extraction Combined with HPLC-UV for Simultaneous Preconcentration and Determination of Urinary Hippuric Acid and Mandelic Acid

    Directory of Open Access Journals (Sweden)

    Abdulrahman Bahrami

    2017-02-01

    Full Text Available This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L−1 sodium chloride, liquid membrane containing 1-octanol with 20% (w/v tributyl phosphate as the carrier, the time of extraction was 150 min, and stirring rate was 500 rpm. The organic phase immobilized in the pores of a hollow fiber was back-extracted into 24 µL of a solution containing sodium carbonate with pH 11, which was placed inside the lumen of the fiber. Under optimized conditions, the high enrichment factors of 172 and 195 folds, detection limit of 0.007 and 0.009 µg·mL−1 were obtained. The relative standard deviation (RSD (% values for intra- and inter-day precisions were calculated at 2.5%–8.2% and 4.1%–10.7%, respectively. The proposed method was successfully applied to the analysis of these metabolites in real urine samples. The results indicated that hollow-fiber liquid-phase microextraction (HF-LPME based on facilitated pH gradient transport can be used as a sensitive and effective method for the determination of mandelic acid and hippuric acid in urine specimens.

  17. Hollow Fiber Supported Liquid Membrane Extraction Combined with HPLC-UV for Simultaneous Preconcentration and Determination of Urinary Hippuric Acid and Mandelic Acid

    Science.gov (United States)

    Bahrami, Abdulrahman; Ghamari, Farhad; Yamini, Yadollah; Ghorbani Shahna, Farshid; Moghimbeigi, Abbas

    2017-01-01

    This work describes a new extraction method with hollow-fiber liquid-phase microextraction based on facilitated pH gradient transport for analyzing hippuric acid and mandelic acid in aqueous samples. The factors affecting the metabolites extraction were optimized as follows: the volume of sample solution was 10 mL with pH 2 containing 0.5 mol·L−1 sodium chloride, liquid membrane containing 1-octanol with 20% (w/v) tributyl phosphate as the carrier, the time of extraction was 150 min, and stirring rate was 500 rpm. The organic phase immobilized in the pores of a hollow fiber was back-extracted into 24 µL of a solution containing sodium carbonate with pH 11, which was placed inside the lumen of the fiber. Under optimized conditions, the high enrichment factors of 172 and 195 folds, detection limit of 0.007 and 0.009 µg·mL−1 were obtained. The relative standard deviation (RSD) (%) values for intra- and inter-day precisions were calculated at 2.5%–8.2% and 4.1%–10.7%, respectively. The proposed method was successfully applied to the analysis of these metabolites in real urine samples. The results indicated that hollow-fiber liquid-phase microextraction (HF-LPME) based on facilitated pH gradient transport can be used as a sensitive and effective method for the determination of mandelic acid and hippuric acid in urine specimens. PMID:28208685

  18. Ribosomes in the sea: a window on taxon-specific lysis

    Science.gov (United States)

    Suttle, C.; Zhong, X.; Wirth, J.

    2016-02-01

    Microbes are estimated to comprise more than 90% of the biomass in the world's oceans, are major drivers of biogeochemical cycles, and have turnover rates ranging from hours to days. Despite the central role that microbes play in marine ecosystems, there is no robust method to evaluate taxon-specific mortality rates. Here, we report a method that employs extracellular free-ribosomes as a proxy to evaluate taxon-specific microbial lysis. The method was validated with laboratory cultures of the marine heterotrophic bacterium Vibrio natriegens strain PWH3a and the photoautotroph Synechococcus strain DC2, with and without grazers or viruses, to identify the origin and fate of the extracellular free-ribosomes. Our results showed both viral lysis and programmed-cell-death (PCD) contribute to free-ribosome production. Ribosomes were not released when cells were grazed, but grazers could consume free-ribosomes. We show that extracellular free-ribosomes can be used to evaluate microbial mortality caused by viral lysis and PCD. This approach was applied to environmental samples by examining the taxonomic composition and relative abundance of free 16S-ribosomes in seawater samples collected from the Strait of Georgia and Saanich Inlet, British Columbia, Canada. Based on the presence of free ribosomes, lysis was detected in 2198 out of 4013 prokaryotic taxa, representing 22 bacterial and three archaeal phyla. Of these, lysis of 140 taxa could be detected in all nine samples. Based on the ratio of free ribosomes to cellular ribosomes, some taxa associated with specific ecological niches appeared to be subject to high rates of lysis, including the genera Achromobacter, Chryseobacterium, Clostridium, Delftia, Ferruginibacter, Lactobacillus, Marinomonas, Massilia, Microbacterium, Ochrobactrum, Paenibacillus, Phyllobacterium, Pseudomonas, Rhodobacter, and Stenotrophomonas. Our results showed high-lysis coupled with low-abundance, suggesting that taxa in lower abundance are subject

  19. Polymer-immobilized liquid membrane transport of palladium (II) from nitric acid media using some thia extractants as novel receptors

    International Nuclear Information System (INIS)

    Shukla, J.P.

    1996-01-01

    Carrier-facilitated co-transport of Pd (II) from dilute acidic nitrate solutions was examined across a polymer-immobilized liquid membrane (PILM) deploying S 6 -pentano-36 (S 6 -P-36), bis-(2-ethylhexyl) sulfoxide (BESO) and bis (2, 4, 4 trimethyl pentyl) monothio phosphinic acid (Cyanex 302) as the novel receptors. The study carried out to distinguish the driving force between H + and NO 3 - ion for the cation transport across PILM, indicated that NO 3 - ion not the H + ion seems to be the driving force for Pd (II) transport under the present conditions for both BESO-PILM and S 6 -P-36-PILM systems. Recovery of palladium from acidic process effluents generated in Purex reprocessing of spent fuels was successfully achieved. 39 refs., 8 figs., 7 tabs

  20. Cauda Equina Syndrome Following an Epidural Lysis Procedure: A Case Report

    Directory of Open Access Journals (Sweden)

    Yasemin Turan

    2017-08-01

    Full Text Available Epidural lysis is known to be one of the therapy methods used following an unsuccessful low back surgery. Despite its proven effectiveness, several complications associated with epidural lysis procedure have been reported. The most common complications are dural perforation, breaking of the catheter and infections. Cauda equina syndrome is a rare complication seen after epidural lysis. A 51-year-old female complaining of lower back pain for six years underwent an epidural lysis procedure at the lumbar 3-4-5 level. Following the procedure, the patient was not able to walk due to weakness starting in both lower extremities, besides, she had fecal and urinary incontinence. After being diagnosed with cauda equina syndrome, a rehabilitation program was administered. After three months, the patient was ambulant with a bilateral dynamic carbon fiber ankle foot orthoses and a walker. It should be kept in mind that serious complications such as cauda equina syndrome, which may considerably affect the patients’ quality of life in a negative way, might develop after an epidural lysis procedure.

  1. Low-dose steroid-induced tumor lysis syndrome in a hepatocellular carcinoma patient

    Directory of Open Access Journals (Sweden)

    Jin Ok Kim

    2015-03-01

    Full Text Available Tumor lysis syndrome is rare in hepatocellular carcinoma (HCC, but it has been reported more frequently recently in response to treatments such as transcatheter arterial chemoembolization (TACE, radiofrequency thermal ablation (RFTA, and sorafenib. Tumor lysis syndrome induced by low-dose steroid appears to be very unusual in HCC. We report a patient with hepatitis-C-related liver cirrhosis and HCC in whom tumor lysis syndrome occurred due to low-dose steroid (10 mg of prednisolone. The patient was a 90-year-old male who presented at the emergency room of our hospital with general weakness and poor oral intake. He had started to take prednisolone to treat adrenal insufficiency 2 days previously. Laboratory results revealed hyperuricemia, hyperphosphatemia, and increased creatinine. These abnormalities fulfilled the criteria in the Cairo-Bishop definition of tumor lysis syndrome. Although the patient received adequate hydration, severe metabolic acidosis and acute kidney injury progressed unabated. He finally developed multiple organ failure, and died 3 days after admission. This was a case of tumor lysis syndrome caused by administration of low-dose steroid in a patient with HCC.

  2. Roles of bacteriophage GVE2 endolysin in host lysis at high temperatures.

    Science.gov (United States)

    Jin, Min; Ye, Ting; Zhang, Xiaobo

    2013-08-01

    The holin-endolysin system is used by double-stranded DNA phages to lyse their bacterial hosts at the terminal stage of the phage reproduction cycle. Endolysins are proteins with one of several muralytic activities able to digest the bacterial cell wall for phage progeny release. However, the functions of thermophilic bacteriophage endolysin in host lysis have not been extensively investigated. In this study, the roles of the endolysin of a thermophilic bacteriophage, GVE2, from a deep-sea hydrothermal vent, which could infect Geobacillus sp. E263 at high temperatures, were characterized. The results showed that GVE2 could lead to lysis of host cells. The confocal microscopy data showed that GFP-endolysin aggregated in GVE2-infected Geobacillus sp. E263 cells, showing the involvement of endolysin in the lysis process at high temperatures. The results revealed that the GVE2 endolysin and holin interacted directly. It was found that the endolysin could interact with the host protein ABC transporter, suggesting that host proteins might participate in the regulation of the lysis process. Therefore, our study presents a novel insight into the mechanism of the lysis process of a thermophilic bacterium by its phage at high temperatures, which should be helpful in revealing the roles of thermophilic bacteriophages in the biosphere of deep-sea hydrothermal vents.

  3. Electromembrane extraction

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Chen, Zhiliang; Gjelstad, Astrid

    2017-01-01

    Electromembrane extraction (EME) was inspired by solid-phase microextraction and developed from hollow fiber liquid-phase microextraction in 2006 by applying an electric field over the supported liquid membrane (SLM). EME provides rapid extraction, efficient sample clean-up and selectivity based ...

  4. On-site monitoring of biogenic emissions from Eucalyptus dunnii leaves using membrane extraction with sorbent interface combined with a portable gas chromatograph system.

    Science.gov (United States)

    Liu, Xinyu; Pawliszyn, Richard; Wang, Limei; Pawliszyn, Janusz

    2004-01-01

    Membrane extraction with sorbent interface, combined with a portable gas chromatograph system (MESI-Portable GC) for continuous on-line monitoring of biogenic volatile organic compounds (BVOCs) emissions (from leaves of Eucalytus dunnii in a greenhouse), is presented herein. A sampling chamber was designed to facilitate the extraction and identification of the BVOCs emitted by the Eucalytus dunnii leaves. Preliminary experiments, including; enrichment times, microtrap temperatures, stripping gas flow rates, and desorption temperatures were investigated to optimize experimental parameters. The main components of BVOCs released by the Eucalytus dunnii leaves were identified by comparing the retention times of peaks with those of authentic standard solutions. They were then confirmed with solid phase microextraction coupled with gas chromatography and mass spectrometry (SPME-GC-MS). BVOC emission profiles of [small alpha]-pinene, eucalyptol, and [gamma]-terpinene emitted by intact and damaged Eucalytus dunnii leaves were obtained. The findings suggest that the MESI-Portable GC system is a simple and useful tool for field monitoring changes in plant emissions as a function of time.

  5. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Valentine, E-mail: valentine.minet@unamur.be; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: julie.laloy@unamur.be [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)

    2015-07-15

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  6. Evaluating the role of desorption in bioavailability of sediment-associated contaminants using oligochaetes, semipermeable membrane devices and Tenax extraction

    International Nuclear Information System (INIS)

    Leppaenen, Matti T.; Kukkonen, Jussi V.K.

    2006-01-01

    The success of the rapidly desorbing fraction as an available fraction was challenged by using sediment ingesting and non-ingesting oligochaetes (Lumbriculus variegatus) together with passive samplers (semipermeable membrane devices, SPMDs) in accumulation and kinetic modelling exercises for carbon-14 labelled model compounds (pyrene, benzo[a]pyrene and 3,4,3',4'-tetrachlorobiphenyl). Passive samplers clearly produced lower uptake rate constants and steady state factors than either of the oligochaete treatments when residue concentrations were based on animal lipid or total SPMD weight. The rapidly desorbing chemical fractions in sediments did not show a significant relationship with the biota sediment accumulation factors or SPMD accumulation factors. A distinctly better relationship was observed between the accumulation factors and the desorption rate constants. The results support the assumption that desorption plays an important role in bioavailability, although animal behaviour and the diffusional limitations of hydrophobic contaminants in sediment together probably affect the actual available pool. - Desorption and animal behaviour play major roles in the availability of hydrophobic organics in sediments

  7. Jk(a-b-) phenotype screening by the urea lysis test in Thai blood donors.

    Science.gov (United States)

    Deelert, Suparat; Thippayaboon, Pattrawan; Sriwai, Wimolpak; Sriwanitchrak, Pramote; Tubrod, Jintana; Kupatawintu, Pawinee; Nathalang, Oytip

    2010-01-01

    The Jk(a-b-) phenotype is rare in most populations and often detected after transfusion or pregnancy. After immunisation, anti-Jk3 forms and it can be difficult to find compatible Jk(a-b-) donors. Using anti-Jk(a) and anti-Jk(b) in a conventional tube method is unsuitable for identifying Jk(a-b-) in mass screening of blood donors. Jk(a-b-) phenotypes are associated with the absence of urea transporters on erythrocytes, making red blood cells (RBC) resistant to lysis by 2M urea, while Jk(a+b-), Jk(a-b+) and Jk(a+b+) phenotypes are susceptible to lysis. We screened for Jk(a-b-) phenotypes in blood donors by the urea lysis test using a 96-well microplate. The Jk(a-b-) phenotypes were confirmed by the indirect antiglobulin test (IAT). Altogether, 20,163 blood samples from Thai blood donors were tested and only RBC from five samples were resistant to lysis by 2M urea, while 20,158 samples were completely lysed within 5 min. In an IAT, both anti-Jk(a) and anti-Jk(b) failed to agglutinate RBC from all five samples. Using a micro-titre plate, the direct urea lysis test, costs * 0.01, about 480 times less than IAT. Moreover, the test time for each plate (94 samples) is about 18 times less than that for IAT. Jk(a-b-) phenotype screening by the direct urea lysis test on samples in a micro-titre plate is simple, cost-effective and practical for mass screening of blood donors.

  8. Jk(a−b−) phenotype screening by the urea lysis test in Thai blood donors

    Science.gov (United States)

    Deelert, Suparat; Thippayaboon, Pattrawan; Sriwai, Wimolpak; Sriwanitchrak, Pramote; Tubrod, Jintana; Kupatawintu, Pawinee; Nathalang, Oytip

    2010-01-01

    Background The Jk(a−b−) phenotype is rare in most populations and often detected after transfusion or pregnancy. After immunisation, anti-Jk3 forms and it can be difficult to find compatible Jk(a−b−) donors. Using anti-Jka and anti-Jkb in a conventional tube method is unsuitable for identifying Jk(a−b−) in mass screening of blood donors. Jk(a−b−) phenotypes are associated with the absence of urea transporters on erythrocytes, making red blood cells (RBC) resistant to lysis by 2M urea, while Jk(a+b−), Jk(a−b+) and Jk(a+b+) phenotypes are susceptible to lysis. Materials and methods. We screened for Jk(a−b−) phenotypes in blood donors by the urea lysis test using a 96-well microplate. The Jk(a−b−) phenotypes were confirmed by the indirect antiglobulin test (IAT). Results Altogether, 20,163 blood samples from Thai blood donors were tested and only RBC from five samples were resistant to lysis by 2M urea, while 20,158 samples were completely lysed within 5 min. In an IAT, both anti-Jka and anti-Jkb failed to agglutinate RBC from all five samples. Using a micro-titre plate, the direct urea lysis test, costs • 0.01, about 480 times less than IAT. Moreover, the test time for each plate (94 samples) is about 18 times less than that for IAT. Conclusion Jk(a−b−) phenotype screening by the direct urea lysis test on samples in a micro-titre plate is simple, cost-effective and practical for mass screening of blood donors. PMID:20104274

  9. Lysis-deficient phages as novel therapeutic agents for controlling bacterial infection

    Directory of Open Access Journals (Sweden)

    Kempashanaiah Nanjundappa

    2011-08-01

    Full Text Available Abstract Background Interest in phage therapy has grown over the past decade due to the rapid emergence of antibiotic resistance in bacterial pathogens. However, the use of bacteriophages for therapeutic purposes has raised concerns over the potential for immune response, rapid toxin release by the lytic action of phages, and difficulty in dose determination in clinical situations. A phage that kills the target cell but is incapable of host cell lysis would alleviate these concerns without compromising efficacy. Results We developed a recombinant lysis-deficient Staphylococcus aureus phage P954, in which the endolysin gene was rendered nonfunctional by insertional inactivation. P954, a temperate phage, was lysogenized in S. aureus strain RN4220. The native endolysin gene on the prophage was replaced with an endolysin gene disrupted by the chloramphenicol acetyl transferase (cat gene through homologous recombination using a plasmid construct. Lysogens carrying the recombinant phage were detected by growth in presence of chloramphenicol. Induction of the recombinant prophage did not result in host cell lysis, and the phage progeny were released by cell lysis with glass beads. The recombinant phage retained the endolysin-deficient genotype and formed plaques only when endolysin was supplemented. The host range of the recombinant phage was the same as that of the parent phage. To test the in vivo efficacy of the recombinant endolysin-deficient phage, immunocompromised mice were challenged with pathogenic S. aureus at a dose that results in 80% mortality (LD80. Treatment with the endolysin-deficient phage rescued mice from the fatal S. aureus infection. Conclusions A recombinant endolysin-deficient staphylococcal phage has been developed that is lethal to methicillin-resistant S. aureus without causing bacterial cell lysis. The phage was able to multiply in lytic mode utilizing a heterologous endolysin expressed from a plasmid in the propagation host

  10. Lysis-deficient phages as novel therapeutic agents for controlling bacterial infection

    Science.gov (United States)

    2011-01-01

    Background Interest in phage therapy has grown over the past decade due to the rapid emergence of antibiotic resistance in bacterial pathogens. However, the use of bacteriophages for therapeutic purposes has raised concerns over the potential for immune response, rapid toxin release by the lytic action of phages, and difficulty in dose determination in clinical situations. A phage that kills the target cell but is incapable of host cell lysis would alleviate these concerns without compromising efficacy. Results We developed a recombinant lysis-deficient Staphylococcus aureus phage P954, in which the endolysin gene was rendered nonfunctional by insertional inactivation. P954, a temperate phage, was lysogenized in S. aureus strain RN4220. The native endolysin gene on the prophage was replaced with an endolysin gene disrupted by the chloramphenicol acetyl transferase (cat) gene through homologous recombination using a plasmid construct. Lysogens carrying the recombinant phage were detected by growth in presence of chloramphenicol. Induction of the recombinant prophage did not result in host cell lysis, and the phage progeny were released by cell lysis with glass beads. The recombinant phage retained the endolysin-deficient genotype and formed plaques only when endolysin was supplemented. The host range of the recombinant phage was the same as that of the parent phage. To test the in vivo efficacy of the recombinant endolysin-deficient phage, immunocompromised mice were challenged with pathogenic S. aureus at a dose that results in 80% mortality (LD80). Treatment with the endolysin-deficient phage rescued mice from the fatal S. aureus infection. Conclusions A recombinant endolysin-deficient staphylococcal phage has been developed that is lethal to methicillin-resistant S. aureus without causing bacterial cell lysis. The phage was able to multiply in lytic mode utilizing a heterologous endolysin expressed from a plasmid in the propagation host. The recombinant phage

  11. A novel integrated strategy for detection of human bocavirus based on a heminested PCR assay combined with boiling lysis method of samples in human specimens.

    Science.gov (United States)

    Chen, Long; Yao, Qing; Ma, Jing; Li, Jianning; Zhang, Qian; Yang, Yi; Li, Fang; Sun, Yuning

    2014-07-01

    Human bocavirus (HBoV) has been shown to be associated with acute respiratory tract infection in children. The aim of the work was to develop a novel integrated strategy for human bocavirus detection: heminested PCR assay combined with boiling lysis method of samples. The detection limit of the heminested PCR assay was 1.2 copies of a recombinant DNA plasmid, and no cross-reaction with other respiratory viruses or bacteria was observed. By using the integrated strategy, a total of 202 secretions of the lower respiratory tract of children with acute respiratory diseases were collected and tested. The samples were treated and lysed in boiling lysis buffer rather than extracting viral DNA from secretions, then these sample lysates could be templates and tested by heminested PCR assay, and the amplification of HBoV DNA was detected by using agarose gel electrophoresis. The results showed that, only 7 samples were found to be positive by conventional single-round PCR; importantly, the other new 41 samples were positive by heminested PCR assay. Additionally, the genomic viral DNA was extracted from all positive and some negative specimens, amplified, and sequenced. The results were perfectly consistent with those of the integrated strategy. Taken together, these results suggest that the novel integrated strategy (heminested PCR assay combined with boiling lysis method of samples) is a convenient, sensitive, cost-effective and reliable detective method for HBoV detection and will have broad application prospects in clinical diagnosis. Copyright © 2014 Elsevier B.V. All rights reserved.

  12. Severe acute tumor lysis syndrome in patients with germ-cell tumors

    Directory of Open Access Journals (Sweden)

    Guilherme Alvarenga Feres

    2008-01-01

    Full Text Available Germ-cell tumors are a high-proliferative type of cancer that may evolve to significant bulky disease. Tumor lysis syndrome is rarely reported in this setting. The reports of three patients with germ-cell tumors who developed severe acute tumor lysis syndrome following the start of their anticancer therapy are presented. All patients developed renal dysfunction and multiorgan failure. Patients with extensive germ-cell tumors should be kept on close clinical and laboratory monitoring. Physicians should be aware of this uncommon but severe complication and consider early admission to the intensive care unit for the institution of measures to prevent acute renal failure.

  13. Tumor lysis syndrome following endoscopic radiofrequency interstitial thermal ablation of colorectal liver metastases.

    LENUS (Irish Health Repository)

    Barry, B D

    2012-02-03

    Radiofrequency interstitial thermal ablation (RITA) provides a palliative option for patients suffering from metastatic liver disease. This procedure can be performed using a laparoscopic approach with laparoscopic ultrasound used to position the RITA probe. We describe a case of laparoscopic RITA performed for colorectal liver metastasis that was complicated by tumor lysis syndrome (TLS) following treatment. We consider RITA to be a safe procedure, as supported by the literature, but where intracorporal tumor lysis is the treatment goal we believe that the systemic release of tumor products can overwhelm the excretory capacity; therefore, TLS is an inevitable consequence in some patients.

  14. The Influence of Emulgator on Stability of Emulsion H3PO4 in Topo-Kerosene and Efficiency at Emulsion Membrane Extraction of La and Nd Concentrate Product of Monazite Sand Treatment

    International Nuclear Information System (INIS)

    Purwani, MV.; Bintarti, AN.; Subagiono, R.

    2002-01-01

    The making of La and Nd concentrate from monazite sand have been done. The separation of La and Nd by emulsion 1M H 3 PO 4 in 5 % TOPO-Kerosene membrane extraction. The feed or aqueous phase was La and Nd concentrate in 1M HNO 3 . Emulgator Span-80 and Tween-80 were used to stabilize emulsion membrane. The influence parameters were percentage of Span-80 and ratio of Span-80 and Tween-80. After formation of emulsion membrane, the extraction process was carried out. Ratio of volume of feed : volume membrane phase = 1 : 1, ratio of volume of 5% TOPO - Kerosene : ratio of volume of 1M H 3 PO 4 1 : 1. The best yield were obtained time of emulsification was 10 minutes with the speed of emulsion was 6000 rpm and concentration of span-80 was 5%. At this condition was obtained the extraction efficiency of La was 55.55%, the extraction efficiency of Nd was 41.6% the stripping efficiency of La was 35.05%, the stripping efficiency of Nd was 87.32 %, the total efficiency of La was 19.46%, the total efficiency of Nd was 36.30% and Separation factor of Nd and La = 1.87. (author)

  15. Protective effects of Sesamum indicum extract against oxidative stress induced by vanadium on isolated rat hepatocytes.

    Science.gov (United States)

    Hosseini, Mir-Jamal; Shahraki, Jafar; Tafreshian, Saman; Salimi, Ahmad; Kamalinejad, Mohammad; Pourahmad, Jalal

    2016-08-01

    Vanadium toxicity is a challenging problem to human and animal health with no entirely understanding cytotoxic mechanisms. Previous studies in vanadium toxicity showed involvement of oxidative stress in isolated liver hepatocytes and mitochondria via increasing of ROS formation, release of cytochrome c and ATP depletion after incubation with different concentrations (25-200 µM). Therefore, we aimed to investigate the protective effects of Sesamum indicum seed extract (100-300 μg/mL) against oxidative stress induced by vanadium on isolated rat hepatocytes. Our results showed that quite similar to Alpha-tocopherol (100 µM), different concentrations of extract (100-300 μg/mL) protected the isolated hepatocyte against all oxidative stress/cytotoxicity markers induced by vanadium in including cell lysis, ROS generation, mitochondrial membrane potential decrease and lysosomal membrane damage. Besides, vanadium induced mitochondrial/lysosomal toxic interaction and vanadium reductive activation mediated by glutathione in vanadium toxicity was significantly (P Sesamum indicum extracts. These findings suggested a hepato-protective role for extracts against liver injury resulted from vanadium toxicity. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 979-985, 2016. © 2015 Wiley Periodicals, Inc.

  16. Complement lysis activity in autologous plasma is associated with lower viral loads during the acute phase of HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Michael Huber

    2006-11-01

    Full Text Available BACKGROUND: To explore the possibility that antibody-mediated complement lysis contributes to viremia control in HIV-1 infection, we measured the activity of patient plasma in mediating complement lysis of autologous primary virus. METHODS AND FINDINGS: Sera from two groups of patients-25 with acute HIV-1 infection and 31 with chronic infection-were used in this study. We developed a novel real-time PCR-based assay strategy that allows reliable and sensitive quantification of virus lysis by complement. Plasma derived at the time of virus isolation induced complement lysis of the autologous virus isolate in the majority of patients. Overall lysis activity against the autologous virus and the heterologous primary virus strain JR-FL was higher at chronic disease stages than during the acute phase. Most strikingly, we found that plasma virus load levels during the acute but not the chronic infection phase correlated inversely with the autologous complement lysis activity. Antibody reactivity to the envelope (Env proteins gp120 and gp41 were positively correlated with the lysis activity against JR-FL, indicating that anti-Env responses mediated complement lysis. Neutralization and complement lysis activity against autologous viruses were not associated, suggesting that complement lysis is predominantly caused by non-neutralizing antibodies. CONCLUSIONS: Collectively our data provide evidence that antibody-mediated complement virion lysis develops rapidly and is effective early in the course of infection; thus it should be considered a parameter that, in concert with other immune functions, steers viremia control in vivo.

  17. Rapid and simple one-step membrane extraction for the determination of 8-hydroxy-2'-deoxyguanosine in human plasma by a combination of on-line solid phase extraction and LC-MS/MS.

    Science.gov (United States)

    Wang, Chien-Jen; Yang, Ning-Hsiang; Chang, Chia-Chi; Liou, Saou-Hsing; Lee, Hui-Ling

    2011-11-15

    A quantitative analytical method using automated on-line solid phase extraction (SPE) and liquid chromatography-electrospray tandem mass spectrometry (LC-ESI-MS/MS) for the determination of 8-OHdG (8-hydroxy-2'-deoxyguanosine) in human plasma was developed and validated. A one-step membrane extraction method for the plasma sample preparation and a C18 SPE column with simple extraction and purification were used for the on-line extraction. A C18 column was employed for LC separation and ESI-MS/MS was utilized for detection. (15)N(5)-8-OHdG ((15)N(5)-8-hydroxy-2'-deoxyguanosine) was used as an internal standard for quantitative determination. The extraction, clean-up and analysis procedures were controlled by a fully automated six-port switch valve as one strategy to reduce the matrix effect and simultaneously improve detection sensitivity. Identification and quantification were based on the following transitions: m/z 284→168 for 8-OHdG and m/z 289→173 for (15)N(5)-8-OHdG. Satisfactory recovery was obtained, and the recovery ranged from 95.1 to 106.1% at trace levels in human plasma and urine, with a CV lower than 5.4%. Values for intraday and interday precision were between 2.3 and 6.8% for plasma and between 2.7 and 4.5% for urine, respectively. Values for the method accuracy of intraday and interday assays ranged from 93.0 and 100.5% for plasma and 110.2 and 119.4% for urine, respectively. The limits of detection (LOD) and LOQ were 0.008 ng/mL and 0.02 ng/mL, respectively.The applicability of this newly developed method was demonstrated by analysis of human plasma samples for an evaluation of the future risk of oxidative stress status in human exposure to nanoparticles and other diseases. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

  18. Efficiency of Colocasia esculenta leaves extract and histopathological effects on Culex pipiens (Diptera: Culicidae).

    Science.gov (United States)

    El-Monairy, Olfat M

    2015-04-01

    This study evaluated the toxicity of Colocasia esculenta leaves extract on 3rd, 4th instars larvae and pupae of Culex pipiens. Bioassays showed that the 3rd instar larvae was the most susceptible to the different concentrations of extract, where the LC50 after 48 hr. post-exposure was 79.41, 109.65 & 141.25 for the 3rd, 4th instars larvae and pupal stage respectively. The histo-pathological effects of C. esculenta leaves extract on midgut regions and gastric caeca of the 3rd instar larvae were studied. When larvae were treated with 100 ppm of C. esculenta extract, all larvae developed dramatic pathological lesions especially Malpighian tubules were extensively affected. The midgut cells showed morphological deviation from normal ones, through slightly apical degenerated (lysis) of epithelial cells. The epithelial cells with extensive cellular microvilli were shrinkage, the nuclei showed pyknotic characteristic and the peritrophic membrane was appeared discontinuation in compared to control. When the 3rd larval instar was exposed to extract 400 ppm, the epithelial cells, adipose fabric and muscles were extensively affected. Also, the gastric caeca was affected obviously. These observation and alterations in cells of Cx. pipiens larvae are related to the dangerous effect of C. esculent leaves extract.

  19. Antibacterial Activity of Rhodomyrtus tomentosa (Aiton Hassk. Leaf Extract against Clinical Isolates of Streptococcus pyogenes

    Directory of Open Access Journals (Sweden)

    Surasak Limsuwan

    2012-01-01

    Full Text Available Ethanol extract of Rhodomyrtus tomentosa (Aiton Hassk. leaf was evaluated for antibacterial activity against 47 clinical isolates of Streptococcus pyogenes. The extract exhibited good anti-S. pyogenes activity against all the tested isolates with similar minimum inhibitory concentration (MIC, 3.91–62.5 μg mL−1 and minimum bactericidal concentration (MBC, 3.91–62.5 μg mL−1 ranges. No surviving cells were detected at 16 h after treatment with 8 × MIC of the extract. The extract-treated cells demonstrated no lysis and cytoplasmic leakage through the bacterial membrane. Electron micrographs further revealed that the extract did not cause any dramatic changes on the treated cells. Rhodomyrtone, an isolated compound, exhibited good anti-S. pyogenes activity (14 isolates, expressed very low MIC (0.39–1.56 μg mL−1 and MBC (0.39-1.56 μg mL−1 values. Rhodomyrtus tomentosa leaf extract and rhodomyrtone displayed promising antibacterial activity against clinical isolates of S. pyogenes.

  20. Integration of nanoparticle cell lysis and microchip PCR for one-step rapid detection of bacteria.

    Science.gov (United States)

    Wan, Weijie; Yeow, John T W

    2012-04-01

    This paper describes an integrated microchip system as an efficient and cost-effective solution involving Nanotechnology and Lab-on-a-Chip technology for the rapid detection of bacteria. The system is based on using surface-modified gold nanoparticles for efficient cell lysis followed by microchip PCR without having to remove the nanoparticles from the PCR solution. Poly(quaternary ammonium) modified gold nanoparticles are used to provide a novel and efficient cell lysis method without the need to go through time-consuming, expensive and complicated microfabrication processes as most of current cell lysis methods for Lab-on-a-Chip applications do. It also facilitates the integration of cell lysis and PCR by sharing the same reaction chamber as PCR uses. It is integrated with a prototype microchip PCR system consisting of a physical microchip PCR device and an automated temperature control mechanism. The research work explores solutions for the problem of PCR inhibition caused by gold nanoparticles as well as for the problem of non-specific PCR amplification in the integrated microchip system. It also explores the possibility of greatly reducing PCR cycling time to achieve the same result compared to the protocol for a regular PCR machine. The simplicity of the setup makes it easy to be integrated with other Lab-on-a-Chip functional modules to create customized solutions for target applications.

  1. Prevention and treatment of tumor lysis syndrome, and the efficacy and role of rasburicase

    Directory of Open Access Journals (Sweden)

    Alakel N

    2017-02-01

    Full Text Available Nael Alakel,1 Jan Moritz Middeke,1 Johannes Schetelig,1,2 Martin Bornhäuser1 1Department of Internal Medicine I, University Hospital Carl Gustav Carus at the Technische Universitaet Dresden, Dresden, 2German Bone Marrow Donor Center DKMS, Tübigen, Germany Abstract: Tumor lysis syndrome (TLS is a potentially life-threatening condition that occurs in oncologic and hematologic patients with large tumor burden, either due to cytotoxic therapy or, less commonly, spontaneously because of massive tumor cell lysis. TLS is clinically characterized by acute renal failure, hyperuricemia, hyperkalemia, hyperphosphatemia, and hypocalcemia. While limited options are available for treating TLS, identifying patients at high risk for developing TLS and prevention in high-risk patients remain an important aspect in the treatment of cancer patients. In general, treatment of TLS consists of intensive hydration, stimulation of diuresis, and, more specifically, in the use of allopurinol and rasburicase. Rasburicase, a recombinant urate oxidase, rapidly and effectively reduces hyperuricemia, which subsequently significantly decreases the risk of acute renal failure and other clinical manifestations of TLS. For this review, a comprehensive literature search using the term “tumor lysis syndrome” and/or “rasburicase” was performed considering articles listed in MEDLINE. Incidence, prevention, and therapy of TLS with a special focus on the role of rasburicase are discussed. We evaluated 120 relevant articles including 35 case reports, 32 clinical trials, and 14 meta-analyses. Keywords: rasburicase, tumor lysis syndrome, hyperuricemia, acute kidney injury

  2. Quantifying enzymatic lysis: estimating the combined effects of chemistry, physiology and physics.

    Science.gov (United States)

    Mitchell, Gabriel J; Nelson, Daniel C; Weitz, Joshua S

    2010-10-04

    The number of microbial pathogens resistant to antibiotics continues to increase even as the rate of discovery and approval of new antibiotic therapeutics steadily decreases. Many researchers have begun to investigate the therapeutic potential of naturally occurring lytic enzymes as an alternative to traditional antibiotics. However, direct characterization of lytic enzymes using techniques based on synthetic substrates is often difficult because lytic enzymes bind to the complex superstructure of intact cell walls. Here we present a new standard for the analysis of lytic enzymes based on turbidity assays which allow us to probe the dynamics of lysis without preparing a synthetic substrate. The challenge in the analysis of these assays is to infer the microscopic details of lysis from macroscopic turbidity data. We propose a model of enzymatic lysis that integrates the chemistry responsible for bond cleavage with the physical mechanisms leading to cell wall failure. We then present a solution to an inverse problem in which we estimate reaction rate constants and the heterogeneous susceptibility to lysis among target cells. We validate our model given simulated and experimental turbidity assays. The ability to estimate reaction rate constants for lytic enzymes will facilitate their biochemical characterization and development as antimicrobial therapeutics.

  3. Parallel single cell analysis on an integrated microfluidic platform for cell trapping, lysis and analysis

    NARCIS (Netherlands)

    le Gac, Severine; de Boer, Hans L.; Wijnperle, Daniël; Meuleman, W.; Carlen, Edwin; van den Berg, Albert; Kim, Tae Song; Lee, Yoon-Sik; Chung, Taek-Dong; Jeon, Noo Li; Lee, Sang-Hoon; Suh, Kahp-Yang; Choo, Jaebum; Kim, Yong-Kweon

    2009-01-01

    We report here a novel and easily scalable microfluidic platform for the parallel analysis of hundreds of individual cells, with controlled single cell trapping, followed by their lysis and subsequent retrieval of the cellular content for on-chip analysis. The device consists of a main channel and

  4. Quantifying enzymatic lysis: estimating the combined effects of chemistry, physiology and physics

    International Nuclear Information System (INIS)

    Mitchell, Gabriel J; Weitz, Joshua S; Nelson, Daniel C

    2010-01-01

    The number of microbial pathogens resistant to antibiotics continues to increase even as the rate of discovery and approval of new antibiotic therapeutics steadily decreases. Many researchers have begun to investigate the therapeutic potential of naturally occurring lytic enzymes as an alternative to traditional antibiotics. However, direct characterization of lytic enzymes using techniques based on synthetic substrates is often difficult because lytic enzymes bind to the complex superstructure of intact cell walls. Here we present a new standard for the analysis of lytic enzymes based on turbidity assays which allow us to probe the dynamics of lysis without preparing a synthetic substrate. The challenge in the analysis of these assays is to infer the microscopic details of lysis from macroscopic turbidity data. We propose a model of enzymatic lysis that integrates the chemistry responsible for bond cleavage with the physical mechanisms leading to cell wall failure. We then present a solution to an inverse problem in which we estimate reaction rate constants and the heterogeneous susceptibility to lysis among target cells. We validate our model given simulated and experimental turbidity assays. The ability to estimate reaction rate constants for lytic enzymes will facilitate their biochemical characterization and development as antimicrobial therapeutics

  5. A simple and novel modification of comet assay for determination of bacteriophage mediated bacterial cell lysis.

    Science.gov (United States)

    Khairnar, Krishna; Sanmukh, Swapnil; Chandekar, Rajshree; Paunikar, Waman

    2014-07-01

    The comet assay is the widely used method for in vitro toxicity testing which is also an alternative to the use of animal models for in vivo testing. Since, its inception in 1984 by Ostling and Johansson, it is being modified frequently for a wide range of application. In spite of its wide applicability, unfortunately there is no report of its application in bacteriophages research. In this study, a novel application of comet assay for the detection of bacteriophage mediated bacterial cell lysis was described. The conventional methods in bacteriophage research for studying bacterial lysis by bacteriophages are plaque assay method. It is time consuming, laborious and costly. The lytic activity of bacteriophage devours the bacterial cell which results in the release of bacterial genomic material that gets detected by ethidium bromide staining method by the comet assay protocol. The objective of this study was to compare efficacy of comet assay with different assay used to study phage mediated bacterial lysis. The assay was performed on culture isolates (N=80 studies), modified comet assay appear to have relatively higher sensitivity and specificity than other assay. The results of the study showed that the application of comet assay can be an economical, time saving and less laborious alternative to conventional plaque assay for the detection of bacteriophage mediated bacterial cell lysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. A simple and rapid lysis method for preparation of genomic DNA ...

    African Journals Online (AJOL)

    Moreover, the resultant genomic DNA was in good quantity and quality and can be used successfully for restriction endonucleases digestion, PCR amplification and others types of molecular biology manipulations. Keywords: Genomic DNA, lysis, carvacrol, Gram-negative bacteria, Escherichia coli, Erwinia chrysanthemi ...

  7. Lysis of fresh human solid tumors by autologous lymphocytes activated in vitro with lectins

    International Nuclear Information System (INIS)

    Mazumder, A.; Grimm, E.A.; Zhang, H.Z.; Rosenberg, S.A.

    1982-01-01

    Human peripheral blood lymphocytes (PBL), obtained from patients with a variety of cancers, were incubated in vitro with phytohemagglutinin, concanavalin A, and crude or lectin-free T-cell growth factors. The lectin-activated PBL of nine patients were capable of lysing fresh autologous tumor during a 4-hr 51Cr release assay. Multiple metastases from the same patient were equivalently lysed by these activated autologous PBL. No lysis of fresh PBL or lectin-induced lymphoblast cell targets was seen, although tumor, PBL, and lymphoblast cells were shown to be equally lysable using allosensitized cells. The activated cells could be expanded without loss of cytotoxicity in crude or lectin-free T-cell growth factors. The generation of cells lytic to fresh autologous tumor was dependent on the presence of adherent cells, although the lytic cell itself was not adherent. Proliferation was not involved in the induction of lytic cells since equal lysis was induced in irradiated and nonirradiated lymphocytes. Lectin was not required in the lytic assay, and the addition of alpha-methyl-D-mannoside to concanavalin A-activated lymphoid cells did not increase the lysis of fresh tumor cells. Activation by lectin for 3 days appears to be an efficient and convenient method for generating human cells lytic to fresh autologous tumor. These lytic cells may be of value for studies of the cell-mediated lysis of human tumor and possibly for tumor immunotherapy as well

  8. Electrochemical lysis at the stage of endoresection for large posterior intraocular tumors

    Directory of Open Access Journals (Sweden)

    Yu. A. Belyy

    2012-01-01

    Full Text Available Purpose: to design the new combined technique of endoresection with intraoperative intraocular electrochemical lysis at the tumor destruction stage for large posterior intraocular tumors.Methods: 3 patients (3 eyes with large choroidal melanomas t3N0M0 (tumor thickness — 8-10 mm, base diameter — 13-15 mm, juxtapapillary localization. Mean age was 55.4 years old. Endoresection with intraoperational intraocular electrochemical lysis of the tumor was performed. Electrochemical lysis was performed with use of the technical unit ECU 300 (Soering, Germany and the original method of combined intratumoral positioning of two platinum electrodes: anode and cathode.Results: the tumor was removal completely in all 3 cases. the anatomical retinal reattachment was reached in all patients. Sclera was safe in all 3 cases. Visual acuity was not changed (NLP. At the place of the removal tumor a surgical choroidal coloboma without pigmentation all over scleral bed and periphery was shown in all cases in distant postoperative period (from 1.5 to 3 years. No local recurrences or metastasis were revealed in all patients.Conclusion: Further investigations in clinical group are necessarily to determinate the real possibilities of the combined method and the indications for endoresection with intraoperative intraocular electrochemical lysis for large intraocular tumors. 

  9. Peptide-Conjugated Gold Nanoprobe: Intrinsic Nanozyme-Linked Immunsorbant Assay of Integrin Expression Level on Cell Membrane.

    Science.gov (United States)

    Gao, Liang; Liu, Meiqing; Ma, Guifu; Wang, Yaling; Zhao, Lina; Yuan, Qing; Gao, Fuping; Liu, Ru; Zhai, Jiao; Chai, Zhifang; Zhao, Yuliang; Gao, Xueyun

    2015-11-24

    Precisely quantifying the membrane protein expression level on cell surfaces is of vital importance for early cancer diagnosis and efficient treatment. We demonstrate that gold nanoparticle bioconjugated by a rationally designed peptide as nanoprobe possesses selective labeling and accurate quantification capacity of integrin GPIIb/IIIa on the human erythroleukemia cell line. Through selective recognition and marking of integrin, two-photon photoluminescence of the nanoprobe is exploited for direct observation of protein spatial distribution on cell membrane. More importantly, utilizing intrinsic enzyme-like catalysis property of the nanoprobe, the expression level of integrin on human erythroleukemia cells can be quantitatively counted in an amplified and reliable colorimetric assay without cell lysis and protein extraction process. In addition, the analysis of the correlation between the gold nanoparticle and the membrane protein via relevant inductively coupled plasma mass spectrometry measurement verifies the reliability of the new analytical method. It is anticipated that this facile and efficient strategy holds a great promise for a rapid, precise, and reliable quantification of interested functional membrane proteins on the cell surface.

  10. Flame Atomic Absorption Spectrometric Determination of Ultra Traces of Thallium(I) ion after Solid Phase Extraction by Octadecyl Silica Membrane Disk Modified by a New Schiff Base

    International Nuclear Information System (INIS)

    Mashhadizadeh, Mohammad Hossein; Moatafavi, Ali; Allah-Abadi, Hossein; Zadmehr, Mohammad Reza

    2004-01-01

    A simple and reliable method has been developed to selectively separate and concentrate trace amounts of thallium ion from real samples for the subsequent measurement by flame atomic absorption spectrometry (FAAS). Thallium ions are absorbed quantitatively during passage of aqueous real samples through an octadecyl bonded silica membrane disk modified by 4-(4-Chloro-phenylazo)-2-[(4-hydroxy-phenylamino)- methyl]-phenol. The retained Tl + ions are then stripped from the disk quantitatively with a minimal amount of thiosulfate solution as eluent. The proposed method permitted large enrichment factors of about 130 and higher. The relative standard deviation for ten replicate extraction of thallium from 1 L samples containing 5 μg thallium is 1.2%. The break through volume for 5 μg thallium is 1000 mL. The limit of detection of the proposed method is 11.2 ng of Tl + per 1000 mL. The effects of various cationic interferences on the recovery of thallium in binary mixtures were studied. The method was applied to the recovery of Tl + ions from natural water and human hair samples

  11. Helium ion microscopy and ultra-high-resolution scanning electron microscopy analysis of membrane-extracted cells reveals novel characteristics of the cytoskeleton of Giardia intestinalis.

    Science.gov (United States)

    Gadelha, Ana Paula Rocha; Benchimol, Marlene; de Souza, Wanderley

    2015-06-01

    Giardia intestinalis presents a complex microtubular cytoskeleton formed by specialized structures, such as the adhesive disk, four pairs of flagella, the funis and the median body. The ultrastructural organization of the Giardia cytoskeleton has been analyzed using different microscopic techniques, including high-resolution scanning electron microscopy. Recent advances in scanning microscopy technology have opened a new venue for the characterization of cellular structures and include scanning probe microscopy techniques such as ultra-high-resolution scanning electron microscopy (UHRSEM) and helium ion microscopy (HIM). Here, we studied the organization of the cytoskeleton of G. intestinalis trophozoites using UHRSEM and HIM in membrane-extracted cells. The results revealed a number of new cytoskeletal elements associated with the lateral crest and the dorsal surface of the parasite. The fine structure of the banded collar was also observed. The marginal plates were seen linked to a network of filaments, which were continuous with filaments parallel to the main cell axis. Cytoplasmic filaments that supported the internal structures were seen by the first time. Using anti-actin antibody, we observed a labeling in these filamentous structures. Taken together, these data revealed new surface characteristics of the cytoskeleton of G. intestinalis and may contribute to an improved understanding of the structural organization of trophozoites. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Silver(I) complexation of linked 2,2'-dipyridylamine derivatives. Synthetic, solvent extraction, membrane transport and X-ray structural studies.

    Science.gov (United States)

    Antonioli, Bianca; Bray, David J; Clegg, Jack K; Gloe, Kerstin; Gloe, Karsten; Kataeva, Olga; Lindoy, Leonard F; McMurtrie, John C; Steel, Peter J; Sumby, Christopher J; Wenzel, Marco

    2006-10-28

    Synthesis of the 2,2'-dipyridylamine derivatives di-2-pyridylaminomethylbenzene 1, 1,2-bis(di-2-pyridylaminomethyl)benzene 2, 1,3-bis(di-2-pyridylaminomethyl)benzene 3, 2,6-bis(di-2-pyridylaminomethyl)pyridine 4, 1,4-bis(di-2-pyridylaminomethyl)benzene 5, and 1,3,5-tris(di-2-pyridylaminomethyl)benzene 6 are reported together with the single-crystal X-ray structures of 2, 3, and 5. Reaction of individual salts of the type AgX (where X = NO(3)(-), PF(6)(-), ClO(4)(-), or BF(4)(-)) with the above ligands has led to the isolation of thirteen Ag(I) complexes, nine of which have also been characterised by X-ray diffraction. In part, the inherent flexibility of the respective ligands has resulted in the adoption of a range of coordination arrangements. A series of liquid-liquid (H(2)O/CHCl(3)) extraction experiments of Ag(I) with varying concentrations of 1-6 in the organic phase have been undertaken, with the counter ion in the aqueous phase being respectively picrate, perchlorate and nitrate. In general, extraction efficiencies for a given ionophore followed the Hofmeister order of picrate > perchlorate > nitrate; in each case the tris-dpa derivative 6 acting as the most efficient extractant of the six systems investigated. Competitive seven-metal bulk membrane transport experiments (H(2)O/CHCl(3)/H(2)O) employing the above ligands as the ionophore in the organic phase and equimolar concentrations of Co(II), Ni(II), Zn(II), Cu(II), Cd(II), Pb(II) and Ag(I) in the aqueous source phase were also undertaken, with transport occurring against a pH gradient. Under the conditions employed 1 and 5 yielded negligible transport of any of the metals present in the source phase while sole transport selectivity for Ag(I) was observed for 2-4 and 6.

  13. An efficient and cost-effective method for DNA extraction from athalassohaline soil using a newly formulated cell extraction buffer.

    Science.gov (United States)

    Narayan, Avinash; Jain, Kunal; Shah, Amita R; Madamwar, Datta

    2016-06-01

    The present study describes the rapid and efficient indirect lysis method for environmental DNA extraction from athalassohaline soil by newly formulated cell extraction buffer. The available methods are mostly based on direct lysis which leads to DNA shearing and co-extraction of extra cellular DNA that influences the community and functional analysis. Moreover, during extraction of DNA by direct lysis from athalassohaline soil, it was observed that, upon addition of poly ethylene glycol (PEG), isopropanol or absolute ethanol for precipitation of DNA, salt precipitates out and affecting DNA yield significantly. Therefore, indirect lysis method was optimized for extraction of environmental DNA from such soil containing high salts and low microbial biomass (CFU 4.3 × 10 4 per gram soil) using newly formulated cell extraction buffer in combination with low and high speed centrifugation. The cell extraction buffer composition and its concentration were optimized and PEG 8000 (1 %; w/v) and 1 M NaCl gave maximum cell mass for DNA extraction. The cell extraction efficiency was assessed with acridine orange staining of soil samples before and after cell extraction. The efficiency, reproducibility and purity of extracted DNA by newly developed procedure were compared with previously recognized methods and kits having different protocols including indirect lysis. The extracted environmental DNA showed better yield (5.6 ± 0.7 μg g -1 ) along with high purity ratios. The purity of DNA was validated by assessing its usability in various molecular techniques like restriction enzyme digestion, amplification of 16S rRNA gene using PCR and UV-Visible spectroscopy analysis.

  14. Induction of Apoptosis by Methyl Alcohol Extract of Enteromorpha linza

    African Journals Online (AJOL)

    , 5 mM ... lysis buffer (40 mM Tris [pH 8.0], 120 mM, NaCl,. 0.5 % NP-40, 0.1 mM sodium orthovanadate, 2 .... cells were lysed, and then equal amounts of cell lysates were separated on SDS-polyacrylamide gels and transferred to membranes.

  15. Novel Cell Wall Hydrolase CwlC from Bacillus thuringiensis Is Essential for Mother Cell Lysis.

    Science.gov (United States)

    Chen, Xiaomin; Gao, Tantan; Peng, Qi; Zhang, Jie; Chai, Yunrong; Song, Fuping

    2018-04-01

    In this study, a sporulation-specific gene (tentatively named cwlC ) involved in mother cell lysis in Bacillus thuringiensis was characterized. The encoded CwlC protein consists of an N-terminal N -acetylmuramoyl-l-alanine amidase (Mur N Ac-LAA) domain and a C-terminal amidase02 domain. The recombinant histidine-tagged CwlC proteins purified from Escherichia coli were able to directly bind to and digest the B. thuringiensis cell wall. The CwlC point mutations at the two conserved glutamic acid residues (Glu-24 and Glu-140) shown to be critical for the catalytic activity in homologous amidases resulted in a complete loss of cell wall lytic activity, suggesting that CwlC is an N -acetylmuramoyl-l-alanine amidase. Results of transcriptional analyses indicated that cwlC is transcribed as a monocistronic unit and that its expression is dependent on sporulation sigma factor K (σ K ). Deletion of cwlC completely blocked mother cell lysis during sporulation without impacting the sporulation frequency, Cry1Ac protein production, and insecticidal activity. Taken together, our data suggest that CwlC is an essential cell wall hydrolase for B. thuringiensis mother cell lysis during sporulation. Engineered B. thuringiensis strains targeting cwlC , which allows the crystal inclusion to remain encapsulated in the mother cell at the end of sporulation, may have the potential to become more effective biological control agents in agricultural applications since the crystal inclusion remains encapsulated in the mother cell at the end of sporulation. IMPORTANCE Mother cell lysis has been well studied in Bacillus subtilis , which involves three distinct yet functionally complementary cell wall hydrolases. In this study, a novel cell wall hydrolase, CwlC, was investigated and found to be essential for mother cell lysis in Bacillus thuringiensis CwlC of B. thuringiensis only shows 9 and 21% sequence identity with known B. subtilis mother cell hydrolases CwlB and CwlC, respectively

  16. The membrane separation mechanism in protein concentration from the extract of waste press cake in biofuel manufacturing process of Jatropha seeds

    Science.gov (United States)

    Chung, T. W.; Chen, C. K.; Hsu, S. H.

    2017-11-01

    Protein concentration process using filter membrane has a significant advantage on energy saving compared to the traditional drying processes. However, fouling on large membrane area and frequent membrane cleaning will increase the energy consumption and operation cost for the protein concentration process with filter membrane. In this study, the membrane filtration for protein concentration will be conducted and compared with the recent protein concentration technology. The analysis of operating factors for protein concentration process using filter membrane was discussed. The separation mechanism of membrane filtration was developed according to the size difference between the pore of membrane and the particle of filter material. The Darcy’s Law was applied to discuss the interaction on flux, TMP (transmembrane pressure) and resistance in this study. The effect of membrane pore size, pH value and TMP on the steady-state flux (Jst) and protein rejection (R) were studied. It is observed that the Jst increases with decreasing membrane pore size, the Jst increases with increasing TMP, and R increased with decreasing solution pH value. Compare to other variables, the pH value is the most significant variable for separation between protein and water.

  17. Study of the phage production efficiency in the bacterian lysis processes

    International Nuclear Information System (INIS)

    Vidania, R.; Garces, F.; Davila, C.A.

    1979-01-01

    A search for the best production conditions of lambda vir and lambda clear phages in E coli K12 and E coli C 6 00 infected cells respectively is presented. By keeping fixed some parameters of the process as the bacterial and phage generation times and the bacterial burst side, it has been finded that the lysis yield is strongly dependent on the multiplicity and in a lesser degree on the infection time. It appears from the experimental results that other variables are important, as infection eficiency and approach time from phages to bacteria. We will try to describe the lysis phenomenon by a numerical model on the bases of those experimental results. (auth)

  18. Mass entrapment and lysis of Mesodinium rubrum cells in mucus threads observed in cultures with Dinophysis

    DEFF Research Database (Denmark)

    Ojamäe, Karin; Hansen, Per Juel; Lips, Inga

    2016-01-01

    The entrapment and death of the ciliate Mesodinium rubrum in the mucus threads in cultures with Dinophysis is described and quantified. Feeding experiments with different concentrations and predator–prey ratios of Dinophysis acuta, Dinophysis acuminata and M. rubrum to study the motility loss...... and aggregate formation of the ciliates and the feeding behaviour of Dinophysis were carried out. In cultures of either Dinophysis species, the ciliates became entrapped in the mucus, which led to the formation of immobile aggregates of M. rubrum and subsequent cell lysis. The proportion of entrapped ciliates...... was influenced by the concentration of Dinophysis and the ratio of predator and prey in the cultures. At high cell concentrations of prey (136 cells mL−1) and predator (100 cells mL−1), a maximum of 17% of M. rubrum cells became immobile and went through cell lysis. Ciliates were observed trapped in the mucus...

  19. Study of the phage production efficiency in the bacteria lysis processes

    International Nuclear Information System (INIS)

    Vidania Munoz, R. de; Garces, F.; Davila, C. A.

    1979-01-01

    In this work we present a search for the best production conditions of λvir andλ clear phages In E coli K12 and E coli C 6 00 infected cells respectively. By keeping fixed some parameters of the process as the bacterial and phage generation times and (he bacterial burst side, we have finder that the lysis yield is strongly dependent on the multiplicity and in a lesser degree on the infection time. It appears from the experimental results that other variables are important, as infection efficiency and approach time from phages to bacteria. We will try to describe the lysis phenomenon by a numerical model on the bases of the se experimental results. (Author) 11 refs

  20. [Tumor lysis syndrome in a pregnancy complicated with acute lymphoblastic leukemia].

    Science.gov (United States)

    Álvarez-Goris, M P; Sánchez-Zamora, R; Torres-Aguilar, A A; Briones Garduño, J C

    2016-04-01

    Acute leukemia is rare during pregnancy, affects about 1 in 75,000 pregnancies, of all leukemias diagnosed only 28% are acute lymphoblastic leukemia, this is a risk factor to develop spontaneous tumor lysis syndrome, it's a oncologic complication potentially deadly if the prophylactic treatment its avoided. Cases of acute lymphoblastic leukemia associated with pregnancy has been poorly documented in the literature the association of these two entities to pregnancy is the first report published worldwide, so the information is limited.

  1. Arthroscopic lysis and lavage in patients with temporomandibular anterior disc displacement without reduction

    Czech Academy of Sciences Publication Activity Database

    Machoň, V.; Šedý, Jiří; Klíma, K.; Hirjak, D.; Foltán, R.

    2012-01-01

    Roč. 41, č. 1 (2012), s. 109-113 ISSN 0901-5027 R&D Projects: GA MŠk(CZ) LC554; GA ČR GAP304/10/0320 Grant - others:GA MŠk(CZ) 1M0538 Program:1M Institutional research plan: CEZ:AV0Z50390703 Keywords : temporomandibular joint * arthroscopic lysis * arthroscopic lavage Subject RIV: FJ - Surgery incl. Transplants Impact factor: 1.521, year: 2012

  2. An improved single-step lysis protocol to measure luciferase bioluminescence in Plasmodium falciparum

    Directory of Open Access Journals (Sweden)

    Hasenkamp Sandra

    2012-02-01

    Full Text Available Abstract This report describes the optimization and evaluation of a simple single-step lysis protocol to measure luciferase bioluminescence from genetically modified Plasmodium falciparum. This protocol utilizes a modified commercial buffer to improve speed of assay and consistency in the bioluminescence signal measured by reducing the manipulation steps required to release the cytoplasmic fraction. The utility of this improved assay protocol is demonstrated in typical assays that explore absolute and temporal gene expression activity.

  3. Chemically synthesized silver nanoparticles as cell lysis agent for bacterial genomic DNA isolation

    Science.gov (United States)

    Goswami, Gunajit; Boruah, Himangshu; Gautom, Trishnamoni; Jyoti Hazarika, Dibya; Barooah, Madhumita; Boro, Robin Chandra

    2017-12-01

    Silver nanoparticles (AgNPs) have seen a recent spurt of use in varied fields of science. In this paper, we showed a novel application of AgNP as a promising microbial cell-lysis agent for genomic DNA isolation. We utilized chemically synthesized AgNPs for lysing bacterial cells to isolate their genomic DNA. The AgNPs efficiently lysed bacterial cells to yield good quality DNA that could be subsequently used for several molecular biology works.

  4. Comparison of the lysis-centrifugation and agitated biphasic blood culture systems for detection of fungemia.

    Science.gov (United States)

    Murray, P R

    1991-01-01

    Although the detection of fungemia has been improved by the use of vented or biphasic blood culture bottles, the best recovery and earliest detection have been reported in the Isolator lysis-centrifugation system. It was recently demonstrated that improved detection of both bacteria and fungi was accomplished by mechanically agitating blood culture bottles for the first 24 h of incubation. In this study the detection of fungemia by use of the Isolator system was compared with that of an agitated biphasic system. A total of 182 fungi were isolated from blood specimens inoculated into both culture systems. No difference in the overall recovery of fungi or individual species of yeasts was observed between the two systems. However, all seven isolates of Histoplasma capsulatum were recovered in the Isolator system only. The time required to detect fungemia with each of the two systems was also compared. No statistically significant difference was observed. From the data collected during this 18-month study, it can be concluded that the overall recovery and time of detection of yeasts are equivalent in the lysis-centrifugation system and the agitated biphasic blood culture system. The lysis-centrifugation system is still superior for the detection of filamentous fungi such as H. capsulatum. PMID:1993772

  5. Role of the SRRz/Rz1lambdoid lysis cassette in the pathoadaptive evolution of Shigella.

    Science.gov (United States)

    Leuzzi, Adriano; Grossi, Milena; Di Martino, Maria Letizia; Pasqua, Martina; Micheli, Gioacchino; Colonna, Bianca; Prosseda, Gianni

    2017-06-01

    Shigella, the etiological agent of bacillary dysentery (shigellosis), is a highly adapted human pathogen. It evolved from an innocuous ancestor resembling the Escherichia coli strain by gain and loss of genes and functions. While the gain process concerns the acquisition of the genetic determinants of virulence, the loss is related to the adaptation of the genome to the new pathogenic status and occurs by pathoadaptive mutation of antivirulence genes. In this study, we highlight that the SRRz/Rz 1 lambdoid lysis cassette, even though stably adopted in E. coli K12 by virtue of its beneficial effect on cell physiology, has undergone a significant decay in Shigella. Moreover, we show the antivirulence nature of the SRRz/Rz 1 lysis cassette in Shigella. In fact, by restoring the SRRz/Rz 1 expression in this pathogen, we observe an increased release of peptidoglycan fragments, causing an unbalance in the fine control exerted by Shigella on host innate immunity and a mitigation of its virulence. This strongly affects the virulence of Shigella and allows to consider the loss of SRRz/Rz 1 lysis cassette as another pathoadaptive event in the life of Shigella. Copyright © 2017 Elsevier GmbH. All rights reserved.

  6. Tumor lysis syndrome as a contributory factor to the development of reversible posterior leukoencephalopathy

    International Nuclear Information System (INIS)

    Ozkan, A.; Ozkalemkas, F.; Ali, R.; Ozkocaman, V.; Ozcelik, T.; Altundal, Y.; Tunali, A.; Hakyemez, B.; Taskapilioglu, O.

    2006-01-01

    Reversible posterior leukoencephalopathy syndrome (RPLS) is a recently described clinical and radiological entity comprising headache, seizures, altered level of consciousness and visual disturbances in association with transient posterior cerebral white-matter abnormalities. We report a young woman with Burkitt's lymphoma who developed RPLS after combined chemotherapy administered during the tumor lysis syndrome. The symptoms in this patient fitted well with those of RPLS; they included abrupt alterations in mental status, seizures, headache, visual changes and characteristic neuroradiological findings. She was given further combination chemotherapy without any neurological complications, at which time she had already recovered from both RPLS and tumor lysis syndrome. Although many etiological factors have been reported in the development of RPLS, the underlying mechanism is not yet well understood. With prompt and appropriate management, RPLS is usually reversible, and chemotherapy can be continued after complete recovery from RPLS. We suggest that tumor lysis syndrome should be considered as a contributory factor to the development of RPLS in patients for whom treatment with combined chemotherapy for hematological malignancies is planned. (orig.)

  7. A controllable bacterial lysis system to enhance biological safety of live attenuated Vibrio anguillarum vaccine.

    Science.gov (United States)

    Chu, Teng; Guan, Lingyu; Shang, Pengfei; Wang, Qiyao; Xiao, Jingfan; Liu, Qin; Zhang, Yuanxing

    2015-08-01

    Bacterial strains used as backbone for the generation of vaccine prototypes should exhibit an adequate and stable safety profile. Given the fact that live attenuated vaccines often contain some potential risks in virulence recovery and spread infections, new approaches are greatly needed to improve their biological safety. Here, a critically iron-regulated promoter PviuA was screened from Vibrio anguillarum, which was demonstrated to respond to iron-limitation signal both in vitro and in vivo. By using PviuA as a regulatory switch to control the expression of phage P22 lysis cassette 13-19-15, a novel in vivo inducible bacterial lysis system was established in V. anguillarum. This system was proved to be activated by iron-limitation signals and then effectively lyse V. anguillarum both in vitro and in vivo. Further, this controllable bacterial lysis system, after being transformed into a live attenuated V. anguillarum vaccine strain MVAV6203, was confirmed to significantly improve biological safety of the live attenuated vaccine without impairing its immune protection efficacy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Plasma nanotextured polymeric lab-on-a-chip for highly efficient bacteria capture and lysis.

    Science.gov (United States)

    Tsougeni, K; Papadakis, G; Gianneli, M; Grammoustianou, A; Constantoudis, V; Dupuy, B; Petrou, P S; Kakabakos, S E; Tserepi, A; Gizeli, E; Gogolides, E

    2016-01-07

    We describe the design, fabrication, and successful demonstration of a sample preparation module comprising bacteria cell capture and thermal lysis on-chip with potential applications in food sample pathogen analysis. Plasma nanotexturing of the polymeric substrate allows increase of the surface area of the chip and the antibody binding capacity. Three different anti-Salmonella antibodies were directly and covalently linked to plasma treated chips without any additional linker chemistry or other treatment. Then, the Ab-modified chips were tested for their capacity to bind bacteria in the concentration range of 10(2)-10(8) cells per mL; the module exhibited 100% efficiency in Salmonella enterica serovar Typhimurium bacteria capture for cell suspensions below 10(5) cells per mL (10(4) cells injected with a 100 μL sample volume) and efficiency higher than 50% for 10(7) cells per mL. Moreover, thermal lysis achieved on-chip from as low as 10 captured cells was demonstrated and shown to compare well with off-chip lysis. Excellent selectivity (over 1 : 300) was obtained in a sample containing, in addition to S. Typhimurium and E. coli bacteria.

  9. SV40 late protein VP4 forms toroidal pores to disrupt membranes for viral release.

    Science.gov (United States)

    Raghava, Smita; Giorda, Kristina M; Romano, Fabian B; Heuck, Alejandro P; Hebert, Daniel N

    2013-06-04

    Nonenveloped viruses are generally released from the cell by the timely lysis of host cell membranes. SV40 has been used as a model virus for the study of the lytic nonenveloped virus life cycle. The expression of SV40 VP4 at later times during infection is concomitant with cell lysis. To investigate the role of VP4 in viral release and its mechanism of action, VP4 was expressed and purified from bacteria as a fusion protein for use in membrane disruption assays. Purified VP4 perforated membranes as demonstrated by the release of fluorescent markers encapsulated within large unilamellar vesicles or liposomes. Dynamic light scattering results revealed that VP4 treatment did not cause membrane lysis or change the size of the liposomes. Liposomes encapsulated with 4,4-difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-3-indacene-labeled streptavidin were used to show that VP4 formed stable pores in membranes. These VP4 pores had an inner diameter of 1-5 nm. Asymmetrical liposomes containing pyrene-labeled lipids in the outer monolayer were employed to monitor transbilayer lipid diffusion. Consistent with VP4 forming toroidal pore structures in membranes, VP4 induced transbilayer lipid diffusion or lipid flip-flop. Altogether, these studies support a central role for VP4 acting as a viroporin in the disruption of cellular membranes to trigger SV40 viral release by forming toroidal pores that unite the outer and inner leaflets of membrane bilayers.

  10. Potato tuber proteomics: Comparison of two complementary extraction methods designed for 2-DE of acidic proteins

    NARCIS (Netherlands)

    Delaplace, P.; Wal, van der F.; Dierick, J.F.; Cordewener, J.H.G.; Fauconnier, M.L.; Jardin, du P.; America, A.H.P.

    2006-01-01

    Two protein extraction procedures were tested in order to remove interfering compounds prior to 2-DE of potato tubers. These methods using SDS lysis buffer and phenol-phase extraction were compared regarding the quality of the resulting 2-D gel. While the resolution of SDS extracts on

  11. Blood culture bottles are superior to lysis-centrifugation tubes for bacteriological diagnosis of spontaneous bacterial peritonitis.

    OpenAIRE

    Siersema, P D; de Marie, S; van Zeijl, J H; Bac, D J; Wilson, J H

    1992-01-01

    The conventional method of ascitic fluid culturing was compared with the bedside inoculation of ascites into blood culture bottles and into lysis-centrifugation tubes. The conventional culture method was compared with the blood culture bottle method in 31 episodes of spontaneous bacterial peritonitis (SBP). Cultures were positive with the conventional culture method in 11 (35%) episodes and with the blood culture bottle method in 26 (84%) episodes (P less than 0.001). The lysis-centrifugation...

  12. Sample prep for proteomics of breast cancer: proteomics and gene ontology reveal dramatic differences in protein solubilization preferences of radioimmunoprecipitation assay and urea lysis buffers

    Directory of Open Access Journals (Sweden)

    Ngoka Lambert CM

    2008-10-01

    Full Text Available Abstract Background An important step in the proteomics of solid tumors, including breast cancer, consists of efficiently extracting most of proteins in the tumor specimen. For this purpose, Radio-Immunoprecipitation Assay (RIPA buffer is widely employed. RIPA buffer's rapid and highly efficient cell lysis and good solubilization of a wide range of proteins is further augmented by its compatibility with protease and phosphatase inhibitors, ability to minimize non-specific protein binding leading to a lower background in immunoprecipitation, and its suitability for protein quantitation. Results In this work, the insoluble matter left after RIPA buffer extraction of proteins from breast tumors are subjected to another extraction step, using a urea-based buffer. It is shown that RIPA and urea lysis buffers fractionate breast tissue proteins primarily on the basis of molecular weights. The average molecular weight of proteins that dissolve exclusively in urea buffer is up to 60% higher than in RIPA. Gene Ontology (GO and Directed Acyclic Graphs (DAG are used to map the collective biological and biophysical attributes of the RIPA and urea proteomes. The Cellular Component and Molecular Function annotations reveal protein solubilization preferences of the buffers, especially the compartmentalization and functional distributions. It is shown that nearly all extracellular matrix proteins (ECM in the breast tumors and matched normal tissues are found, nearly exclusively, in the urea fraction, while they are mostly insoluble in RIPA buffer. Additionally, it is demonstrated that cytoskeletal and extracellular region proteins are more soluble in urea than in RIPA, whereas for nuclear, cytoplasmic and mitochondrial proteins, RIPA buffer is preferred. Extracellular matrix proteins are highly implicated in cancer, including their proteinase-mediated degradation and remodelling, tumor development, progression, adhesion and metastasis. Thus, if they are not

  13. Produção de protoplastos e lise da parede celular de leveduras utilizando β-1,3 glucanase Protoplasts production and yeast cell wall lysis using β-1,3 glucanase

    Directory of Open Access Journals (Sweden)

    Luciana Francisco Fleuri

    2010-06-01

    Full Text Available O presente trabalho visou a aplicação da β-1,3 glucanase lítica, obtida do microrganismo Cellulosimicrobium cellulans 191, na produção de protoplastos e na lise da parede celular de leveduras. A preparação bruta da enzima foi capaz de lisar as leveduras Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann e Itaiquara, S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587 e Hansenula mrakii NCYC 500. A β-1,3 glucanase purificada foi capaz de lisar as leveduras Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii e Pichia membranaefaciens e formar protoplastos de Saccharomyces cerevisiae KL-88.The aim of this work was the application of lytic β-1,3 glucanase obtained from Cellulosimicrobium cellulans strain 191 in the production of protoplasts and lysis of yeast cell walls. The crude extract demonstrated lysis activity against the yeasts Kluyveromyces lodderi, Saccharomyces cerevisiae (Fleischmann and Itaiquara, S. cerevisiae KL-88, S. diastaticus NCYC 713, S. cerevisiae NCYC 1001, Candida glabrata NCYC 388, Kluyveromyces marxianus NCYC 587, and Hansenula mrakii NCYC 500. The purified β-1,3 glucanase demonstrated lysis activity against the yeasts Saccharomyces cerevisiae KL-88, Saccharomyces capensis, Debaromyces vanriji, Pachysolen tannophillus, Kluyveromyces drosophilarum, Candida glabrata, Hansenula mrakii, and Pichia membranaefaciens, and it was able to produce Saccharomyces cerevisiae KL-88 protoplasts.

  14. A simple method of genomic DNA extraction suitable for analysis of bulk fungal strains.

    Science.gov (United States)

    Zhang, Y J; Zhang, S; Liu, X Z; Wen, H A; Wang, M

    2010-07-01

    A simple and rapid method (designated thermolysis) for extracting genomic DNA from bulk fungal strains was described. In the thermolysis method, a few mycelia or yeast cells were first rinsed with pure water to remove potential PCR inhibitors and then incubated in a lysis buffer at 85 degrees C to break down cell walls and membranes. This method was used to extract genomic DNA from large numbers of fungal strains (more than 92 species, 35 genera of three phyla) isolated from different sections of natural Ophiocordyceps sinensis specimens. Regions of interest from high as well as single-copy number genes were successfully amplified from the extracted DNA samples. The DNA samples obtained by this method can be stored at -20 degrees C for over 1 year. The method was effective, easy and fast and allowed batch DNA extraction from multiple fungal isolates. Use of the thermolysis method will allow researchers to obtain DNA from fungi quickly for use in molecular assays. This method requires only minute quantities of starting material and is suitable for diverse fungal species.

  15. Zeolite imidazolate frameworks 8 as sorbent and its application to sonication-assisted emulsification microextraction combined with vortex-assisted porous membrane-protected micro-solid-phase extraction for fast analysis of acidic drugs in environmental water samples.

    Science.gov (United States)

    Ge, Dandan; Lee, Hian Kee

    2012-09-28

    A novel and fast procedure, sonication-assisted emulsification microextraction combined with vortex-assisted porous membrane protected micro-solid-phase extraction (SAEME-VA-μ-SPE), was developed for the gas chromatography-mass spectrometric determination of acidic drugs from environmental water samples. One advantage of the new procedure is that any solvent immiscible with water can be used as extractant solvent of SAEME and any solid sorbent can be used for μ-SPE in the SAEME-VA-μ-SPE process. In the present work, zeolite imidazolate framework 8 (ZIF-8) was employed as extraction sorbent for μ-SPE and 1-octanol as extractant solvent for SAEME. ZIF-8 has very good thermal, chemical and water stability, which make it a suitable material for the extraction of trace analytes from aqueous samples. Under the optimized extraction conditions, the developed method exhibited low limits of detection (0.01-0.04 ng/ml), good linearity (with r² between 0.9965 and 0.9993) from 0.5 to 50 ng/ml and satisfactory repeatability (between 4.1% and 7.6%). In essence SAEME-VA-μ-SPE is a combination of two different and efficient miniaturized techniques. It was demonstrated to be a fast, accurate, and convenient pretreatment procedure for trace analysis of environmental water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...

  17. β-1,3 Glucanases e quitinases: aplicação na lise de leveduras e inibição de fungos β-1,3 glucanases and chitinases: application in the yeast cell lysis and fungi inhibition

    Directory of Open Access Journals (Sweden)

    Luciana Francisco Fleuri

    2008-08-01

    Full Text Available Objetivou-se, no presente trabalho, a aplicação de β-1,3 glucanases e quitinases da linhagem Cellulosimicrobium cellulans 191 na lise de leveduras e inibição de fungos, respectivamente. O delineamento experimental mostrou que as melhores condições para a lise de Saccharomyces cerevisiae KL-88 pela β-1,3 glucanase foi pH 6,5 e 35ºC. As células de leveduras incubadas por 10 h em frascos sem agitação mostraram-se mais susceptíveis à lise pela ação da enzima. Foi obtido maior lise da levedura quando a suspensão de células foi submetida ao tratamento com β-1,3 glucanase e cisteína 1mM. A enzima invertase intracelular ou ligada à célula de S. cerevisiae KL-88 e K. marxianus NCYC 587 foi extraída após tratamento da suspensão celular com β-1,3 glucanase, sendo que o tratamento prévio das leveduras com a enzima aumentou a susceptibilidade das células à lise com ultra-som. A preparação de quitinase foi capaz de formar halos de inibição de alguns fungos.The aim of this work was the application of β-1,3 glucanases and chitinases by Cellulosimicrobium cellulans 191 strain on yeast cell lysis and fungi inhibition, respectively. The experimental design study showed that the best conditions to Saccharomyces cerevisiae KL-88 lysis by β-1,3 glucanase extract were pH 6,5 and 35ºC. This study also demonstrated that the yeast cells were more susceptible to lysis after 10 h of cultivation in flasks without agitation. Lysis activity was increased when S. cerevisiae KL-88 cell suspension was treated with β-1,3 glucanase and cystein 1mM. The enzyme invertase of S. cerevisiae KL-88 and Kluyveromyces marxianus NCYC 587 was extracted after treatment of cell suspension with β-1,3 glucanase and the previous treatment of yeasts with the enzyme, increased the susceptibility to lysis when ultrasonic treatment was used. The chitinase presented growth inhibition halos for some of the fungi.

  18. Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis

    Science.gov (United States)

    Mercer, Frances; Diala, Fitz Gerald I.; Chen, Yi-Pei; Molgora, Brenda M.; Ng, Shek Hang; Johnson, Patricia J.

    2016-01-01

    Trichomonas vaginalis (Tv) is an extracellular protozoan parasite that causes the most common non-viral sexually transmitted infection: trichomoniasis. While acute symptoms in women may include vaginitis, infections are often asymptomatic, but can persist and are associated with medical complications including increased HIV susceptibility, infertility, pre-term labor, and higher incidence of cervical cancer. Heightened inflammation resulting from Tv infection could account for these complications. Effective cellular immune responses to Tv have not been characterized, and re-infection is common, suggesting a dysfunctional adaptive immune response. Using primary human leukocyte components, we have established an in vitro co-culture system to assess the interaction between Tv and the cells of the human immune system. We determined that in vitro, Tv is able to lyse T-cells and B-cells, showing a preference for B-cells. We also found that Tv lysis of lymphocytes was mediated by contact-dependent and soluble factors. Tv lysis of monocytes is far less efficient, and almost entirely contact-dependent. Interestingly, a common symbiont of Tv, Mycoplasma hominis, did not affect cytolytic activity of the parasite, but had a major impact on cytokine responses. M. hominis enabled more diverse inflammatory cytokine secretion in response to Tv and, of the cytokines tested, Tv strains cleared of M. hominis induced only IL-8 secretion from monocytes. The quality of the adaptive immune response to Tv is therefore likely influenced by Tv symbionts, commensals, and concomitant infections, and may be further complicated by direct parasite lysis of effector immune cells. PMID:27529696

  19. Leukocyte Lysis and Cytokine Induction by the Human Sexually Transmitted Parasite Trichomonas vaginalis.

    Directory of Open Access Journals (Sweden)

    Frances Mercer

    2016-08-01

    Full Text Available Trichomonas vaginalis (Tv is an extracellular protozoan parasite that causes the most common non-viral sexually transmitted infection: trichomoniasis. While acute symptoms in women may include vaginitis, infections are often asymptomatic, but can persist and are associated with medical complications including increased HIV susceptibility, infertility, pre-term labor, and higher incidence of cervical cancer. Heightened inflammation resulting from Tv infection could account for these complications. Effective cellular immune responses to Tv have not been characterized, and re-infection is common, suggesting a dysfunctional adaptive immune response. Using primary human leukocyte components, we have established an in vitro co-culture system to assess the interaction between Tv and the cells of the human immune system. We determined that in vitro, Tv is able to lyse T-cells and B-cells, showing a preference for B-cells. We also found that Tv lysis of lymphocytes was mediated by contact-dependent and soluble factors. Tv lysis of monocytes is far less efficient, and almost entirely contact-dependent. Interestingly, a common symbiont of Tv, Mycoplasma hominis, did not affect cytolytic activity of the parasite, but had a major impact on cytokine responses. M. hominis enabled more diverse inflammatory cytokine secretion in response to Tv and, of the cytokines tested, Tv strains cleared of M. hominis induced only IL-8 secretion from monocytes. The quality of the adaptive immune response to Tv is therefore likely influenced by Tv symbionts, commensals, and concomitant infections, and may be further complicated by direct parasite lysis of effector immune cells.

  20. Degradation of RNA during lysis of Escherichia coli cells in agarose plugs breaks the chromosome.

    Directory of Open Access Journals (Sweden)

    Sharik R Khan

    Full Text Available The nucleoid of Escherichia coli comprises DNA, nucleoid associated proteins (NAPs and RNA, whose role is unclear. We found that lysing bacterial cells embedded in agarose plugs in the presence of RNases caused massive fragmentation of the chromosomal DNA. This RNase-induced chromosomal fragmentation (RiCF was completely dependent on the presence of RNase around lysing cells, while the maximal chromosomal breakage required fast cell lysis. Cell lysis in plugs without RNAse made the chromosomal DNA resistant to subsequent RNAse treatment. RiCF was not influenced by changes in the DNA supercoiling, but was influenced by growth temperature or age of the culture. RiCF was partially dependent on H-NS, histone-like nucleoid structuring- and global transcription regulator protein. The hupAB deletion of heat-unstable nucleoid protein (HU caused increase in spontaneous fragmentation that was further increased when combined with deletions in two non-coding RNAs, nc1 and nc5. RiCF was completely dependent upon endonuclease I, a periplasmic deoxyribonuclease that is normally found inhibited by cellular RNA. Unlike RiCF, the spontaneous fragmentation in hupAB nc1 nc5 quadruple mutant was resistant to deletion of endonuclease I. RiCF-like phenomenon was observed without addition of RNase to agarose plugs if EDTA was significantly reduced during cell lysis. Addition of RNase under this condition was synergistic, breaking chromosomes into pieces too small to be retained by the pulsed field gels. RNase-independent fragmentation was qualitatively and quantitatively comparable to RiCF and was partially mediated by endonuclease I.

  1. Comparison of three mycobacterial DNA extraction methods from extrapulmonary samples for PCR assay

    Directory of Open Access Journals (Sweden)

    Khandaker Shadia

    2012-01-01

    Full Text Available Sensitivity of the molecular diagnostic tests of extrapulmonary tuberculosis largely depends upon the efficiency of DNA extraction methods. The objective of our study was to compare three methods of extracting DNA of Mycobacterium tuberculosis for testing by polymerase chain reaction. All three methods; heating, heating with sonication and addition of lysis buffer with heating and sonication were implicated on 20 extrapulmonary samples. PCR positivity was 2 (10%, 4 (20% and 7 (35% in the samples extracted by heating, heat+sonication and heat+sonication+lysis buffer method respectively. Of the extraction methods evaluated, maximum PCR positive results were achieved by combined heat, sonication and lysis buffer method which can be applied in routine clinical practice. Ibrahim Med. Coll. J. 2012; 6(1: 9-11

  2. Tumor Lysis Syndrome (TLS following intrathecal chemotherapy in a child with acute myelogenous leukemia (AML

    Directory of Open Access Journals (Sweden)

    Chana L. Glasser, MD

    2017-01-01

    Full Text Available Tumor Lysis Syndrome (TLS is a well-known complication of induction therapy for hematologic malignancies. It is characterized by rapid breakdown of malignant white blood cells (WBCs leading to metabolic derangements and serious morbidity if left untreated. Most commonly, TLS is triggered by systemic chemotherapy, however, there have been case reports of TLS following intrathecal (IT chemotherapy, all in patients with acute lymphoblastic leukemia (ALL/lymphoma. Here, we report the first case of a patient with acute myelogenous leukemia (AML who developed TLS following a single dose of IT cytosine arabinoside (Ara-C.

  3. Chitinase production by Streptomyces viridificans: its potential in fungal cell wall lysis.

    Science.gov (United States)

    Gupta, R; Saxena, R K; Chaturvedi, P; Virdi, J S

    1995-04-01

    Streptomyces viridificans was found to be a good chitinase producer among nine species of Streptomyces screened. Minimum levels of constitutive enzyme were observed with both simple and complex carbon substrate. Arabinose doubled the enzyme production amongst the various pentoses and hexoses used with chitin. However, with glucose end-product inhibition and catabolite repression were observed. The enzyme tolerated a wide range of temperature (30-55 degrees C) and pH (3-7.5). Among various divalent cations Mn2+ and Hg2+ completely inhibited the purified enzyme while beta-mercaptoethanol stimulated its activity. Crude and purified enzyme had potential for cell wall lysis of many fungal pathogens tested.

  4. Surgical treatment of bilateral nondisplaced isthmic lysis by interlaminar fixation device

    Directory of Open Access Journals (Sweden)

    Keyvan Mostofi

    2017-01-01

    Full Text Available Study Design: Spondylolysis is a defect in the portion of pars interarticularis. The latter affects approximately 6% of the population. It is caused by repetitive trauma in hyperextension. Low back pain is the most common symptom. Methods: We implanted interspinous process devices in 12 patients with isthmic lysis without spondylolisthesis for low back pain. The purpose of the surgery was to conduct a minimally invasive procedure. Results: In eight cases, patients became asymptomatic. In two cases, there has been a considerable improvement. In two cases, no change had been noted. Conclusion: This good result motivates us to consider this approach a part of therapeutic arsenal for some cases of spondylolysis.

  5. EDTA-induced membrane fluidization and destabilization: biophysical studies on artificial lipid membranes.

    Science.gov (United States)

    Prachayasittikul, Virapong; Isarankura-Na-Ayudhya, Chartchalerm; Tantimongcolwat, Tanawut; Nantasenamat, Chanin; Galla, Hans-Joachim

    2007-11-01

    The molecular mechanism of ethylenediaminetetraacetic acid (EDTA)-induced membrane destabilization has been studied using a combination of four biophysical techniques on artificial lipid membranes. Data from Langmuir film balance and epifluorescence microscopy revealed the fluidization and expansion effect of EDTA on phase behavior of monolayers of either 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) or mixtures of DPPC and metal-chelating lipids, such as N(alpha),N(alpha)-Bis[carboxymethyl]-N(epsilon)-[(dioctadecylamino)succinyl]-L-lysine or 1,2-dioleoyl-sn-glycero-3-[N-(5-amino-1-carboxypentyl iminodiacetic acid) succinyl]. A plausible explanation could be drawn from the electrostatic interaction between negatively charged groups of EDTA and the positively charged choline head group of DPPC. Intercalation of EDTA into the lipid membrane induced membrane curvature as elucidated by atomic force microscopy. Growth in size and shape of the membrane protrusion was found to be time-dependent upon exposure to EDTA. Further loss of material from the lipid membrane surface was monitored in real time using a quartz crystal microbalance. This indicates membrane restabilization by exclusion of the protrusions from the surface. Loss of lipid components facilitates membrane instability, leading to membrane permeabilization and lysis.

  6. Optimizing factors influencing DNA extraction from fresh whole avian ...

    African Journals Online (AJOL)

    A study was conducted to optimize the efficient combination of lysis buffer, proteinase K, incubation time, phenol-chloroform-isoamyl alcohol (PCI) volume, spinning rate (rpm), and precipitation agent on quantity and quality of DNA extracted from various volumes of avian blood. Blood samples were collected in EDTA and ...

  7. Effect of acetone extract of Rumex japonicas Houtt on hydrogen ...

    African Journals Online (AJOL)

    to manufacturers' instructions. In addition, the total cell proteins of H9c2 cells were extracted with IP cell lysis buffer, and protein concentration was analyzed using a BCA protein assay kit. Subsequently, contents of SOD, CAT and MDA were also measured using commercial kits following manufacturers' instructions. Western ...

  8. Treatment and prevention of tumor lysis syndrome in children. Experience of Associazione Italiana Ematologia Oncologia Pediatrica.

    Science.gov (United States)

    Pession, Andrea; Barbieri, Eveline

    2005-01-01

    Hyperuricemia and tumor lysis syndrome (TLS) are complications that can arise from treatment of rapidly proliferating and drug-sensitive neoplasms. Clinical trials have shown rasburicase, a recombinant urate oxidase to be more effective than allopurinol for the prevention and treatment of malignancy-associated hyperuricemia. We investigated the safety and efficacy of rasburicase in the AIEOP centers' experience. We reviewed the data of 26 children with malignancy at risk for TLS, submitted to treatment (group 1) or prophylaxis (group 2) of acute hyperuricemia with rasburicase (0.20 mg/kg intravenously daily) for a median period of 4 days. Rasburicase produced a significant decrease in uric acid concentrations in all the patients. The control of uric acid levels was obtained in both the groups within 24 h of the first dose with a response rate of 100% (group 1) and 93% (group 2). Normalization of creatinine and phosphorus levels was obtained in 5 and 4 days respectively. Tolerance was excellent without toxicity. These data confirm that rasburicase is a safe, highly and rapidly effective agent in the treatment and prevention of malignancy-associated acute hyperuricemia and could be considered the treatment of choice to prevent tumor lysis syndrome in children at high risk for this metabolic complication.

  9. Susceptibility of pathogenic and nonpathogenic Naegleria spp. to complement-mediated lysis.

    Science.gov (United States)

    Whiteman, L Y; Marciano-Cabral, F

    1987-10-01

    The susceptibility of four species of Naegleria amoebae to complement-mediated lysis was determined. The amoebicidal activity of normal human serum (NHS) and normal guinea pig serum (NGPS) for Naegleria amoebae was measured by an in vitro cytotoxicity assay. Release of radioactivity from amoebae labeled with [3H]uridine and visual observation with a compound microscope were used as indices of lysis. Highly pathogenic mouse-passaged N. fowleri was less susceptible to the lytic effects of NHS and NGPS than the weakly pathogenic, axenically grown N. fowleri or N. australiensis and the nonpathogenic amoebae N. gruberi and N. lovaniensis. However, both pathogenic and nonpathogenic Naegleria spp. depleted complement as assessed by total hemolytic activity. Treatment of serum with EDTA, heat (56 degrees C, 30 min), cobra venom factor, or antibody to C3 or C9 complement components decreased the amoebicidal activity of NHS. The presence of specific agglutinating antibody to N. fowleri enhanced the amoebicidal activity of NGPS for N. fowleri.

  10. Revisiting bistability in the lysis/lysogeny circuit of bacteriophage lambda.

    Directory of Open Access Journals (Sweden)

    Michael Bednarz

    Full Text Available The lysis/lysogeny switch of bacteriophage lambda serves as a paradigm for binary cell fate decision, long-term maintenance of cellular state and stimulus-triggered switching between states. In the literature, the system is often referred to as "bistable." However, it remains unclear whether this term provides an accurate description or is instead a misnomer. Here we address this question directly. We first quantify transcriptional regulation governing lysogenic maintenance using a single-cell fluorescence reporter. We then use the single-cell data to derive a stochastic theoretical model for the underlying regulatory network. We use the model to predict the steady states of the system and then validate these predictions experimentally. Specifically, a regime of bistability, and the resulting hysteretic behavior, are observed. Beyond the steady states, the theoretical model successfully predicts the kinetics of switching from lysogeny to lysis. Our results show how the physics-inspired concept of bistability can be reliably used to describe cellular phenotype, and how an experimentally-calibrated theoretical model can have accurate predictive power for cell-state switching.

  11. Capacity of tumor necrosis factor to augment lymphocyte-mediated tumor cell lysis of malignant mesothelioma

    International Nuclear Information System (INIS)

    Bowman, R.V.; Manning, L.S.; Davis, M.R.; Robinson, B.W.

    1991-01-01

    Recombinant human tumor necrosis factor (rHuTNF) was evaluated both for direct anti-tumor action against human malignant mesothelioma and for its capacity to augment the generation and lytic phases of lymphocyte-mediated cytotoxicity against this tumor. rHuTNF was directly toxic by MTT assay to one of two mesothelioma cell lines evaluated, but had no effect on susceptibility to subsequent lymphocyte-mediated lysis of either line. TNF alone was incapable of generating anti-mesothelioma lymphokine-activated killer cell (LAK) activity. Furthermore, it did not augment the degree or LAK activity produced by submaximal interleukin-2 (IL-2) concentrations nor did it augment lysis of mesothelioma cells by natural killer (NK) or LAK effector cells during the 4-hr 51chromium release cytolytic reaction. The studies also suggest that mesothelioma targets are less responsive to TNF plus submaximal IL-2 concentrations than the standard LAK sensitive target Daudi, raising the possibility that intermediate LAK sensitive tumors such as mesothelioma may require separate and specific evaluation in immunomodulation studies. This in vitro study indicates that use of low-dose rHuTNF and IL-2 is unlikely to be an effective substitute for high-dose IL-2 in generation and maintenance of LAK activity in adoptive immunotherapy for mesothelioma

  12. [Study of a lysis medium stabilizing microfilaments and microtubules in vitro and in vivo].

    Science.gov (United States)

    Foucault, G; Raymond, M N; Coffe, G; Pudles, J

    1984-01-01

    Determination of experimental conditions which allow the evaluation of the variations in the ratio of non polymerized and polymerized forms of actin and tubulin during the reorganization of the cytoskeletal cell system is of most valuable importance. In order to prepare cell homogenates which would reflect the in vivo situation, we tested in vitro a lysis medium which stabilized both microfilaments and microtubules, which were determined by DNase inhibition assays and colchicine binding assays respectively. This lysis medium containing 10 mM potassium phosphate, 1mM magnesium chloride, 5 mM EGTA, 1 M hexylene glycol, 1% Triton X-100, pH 6.4, used at 4 degrees C a) diffused rapidly into the cells; b) did not denature actin and tubulin; c) did not displace the equilibrium between non polymerized and polymerized forms of actin and tubulin, allowing biochemical assays on cell homogenates; d) blocked the evolution of the cytoskeletal system and permitted structural studies; e) and allowed the decoration of microfilaments by heavy meromyosin.

  13. Determination of polycyclic aromatic hydrocarbons (PAHs) from organic aerosols using hollow fiber micro-porous membrane liquid-liquid extraction (HF-MMLLE) followed by gas chromatography-mass spectrometry analysis.

    Science.gov (United States)

    Hyder, Murtaza; Aguilar, Lidia Luque; Genberg, Johan; Sandahl, Margareta; Wesén, Clas; Jönsson, Jan Åke

    2011-08-15

    A method for determination of polycyclic aromatic hydrocarbons (PAHs) from aerosols was developed. Instead of conventionally used non-polar or slightly polar phenylmethylpolysiloxane column a highly polar, highly substituted, cyanopropyl column (VF-23 MS) was used for separation of PAHs. Based on hollow fiber micro-porous membrane liquid-liquid extraction (HF-MMLLE) a method was developed for sample clean up and pretreatment. An enrichment factor of 617-1022 was obtained with extraction efficiency 10.2-18.9% for different PAHs analyzed in this study. The optimized method was successfully applied to aerosol samples and limits of detection between 1.2 pg m(-3) and 180 pg m(-3) was obtained. Almost all PAHs were found in most of the aerosol samples. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Characterization of retrokeratoprosthetic membranes in the Boston type 1 keratoprosthesis.

    Science.gov (United States)

    Stacy, Rebecca C; Jakobiec, Frederick A; Michaud, Norman A; Dohlman, Claes H; Colby, Kathryn A

    2011-03-01

    To evaluate retroprosthetic membranes that can occur in 25% to 65% of patients with the Boston type 1 keratoprosthesis (KPro). Two patients with Peter anomaly and 2 with neurotrophic scarred corneas underwent revisions of their type 1 KPros because of visually compromising retroprosthetic membranes. The excised membranes were studied by light microscopy with hematoxylin-eosin, periodic acid-Schiff, and toluidine blue stains. Immunohistochemical and transmission electron microscopic examination were also used. Light microscopic examination revealed that the retro-KPro fibrous membranes originated from the host's corneal stroma. These mildly to moderately vascularized membranes grew through gaps in the Descemet membrane to reach behind the KPro back plate and adhere to the anterior iris surface, which had undergone partial lysis. In 2 cases, the fibrous membranes merged at the pupil with matrical portions of metaplastic lens epithelium, forming a bilayered structure that crossed the optical axis. Retro-KPro membranes stained positively for α-smooth muscle actin but negatively for pancytokeratin. Electron microscopy confirmed the presence of actin filaments within myofibroblasts and small surviving clusters of metaplastic lens epithelial cells. Stromal downgrowth, rather than epithelial downgrowth, was the major element of the retro-KPro membranes in this series. Metaplastic lens epithelium also contributed to opacification of the visual axis. Florid membranous inflammation was not a prominent finding and thus probably not a requisite stimulus for membrane development. Further advances in prosthetic design and newer antifibroproliferative agents may reduce membrane formation.

  15. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  16. Biobased Membrane

    NARCIS (Netherlands)

    Koenders, E.A.B.; Zlopasa, J.; Picken, S.J.

    2015-01-01

    The present invention is in the field of a composition for forming a bio-compatible membrane applicable to building material, such as concrete, cement, etc., to a meth od of applying said composition for forming a bio-compatible membrane, a biocompatible membrane, use of said membrane for various

  17. Plasma membrane changes during programmed cell deaths.

    Science.gov (United States)

    Zhang, Yingying; Chen, Xin; Gueydan, Cyril; Han, Jiahuai

    2018-01-01

    Ruptured and intact plasma membranes are classically considered as hallmarks of necrotic and apoptotic cell death, respectively. As such, apoptosis is usually considered a non-inflammatory process while necrosis triggers inflammation. Recent studies on necroptosis and pyroptosis, two types of programmed necrosis, revealed that plasma membrane rupture is mediated by MLKL channels during necroptosis but depends on non-selective gasdermin D (GSDMD) pores during pyroptosis. Importantly, the morphology of dying cells executed by MLKL channels can be distinguished from that executed by GSDMD pores. Interestingly, it was found recently that secondary necrosis of apoptotic cells, a previously believed non-regulated form of cell lysis that occurs after apoptosis, can be programmed and executed by plasma membrane pore formation like that of pyroptosis. In addition, pyroptosis is associated with pyroptotic bodies, which have some similarities to apoptotic bodies. Therefore, different cell death programs induce distinctive reshuffling processes of the plasma membrane. Given the fact that the nature of released intracellular contents plays a crucial role in dying/dead cell-induced immunogenicity, not only membrane rupture or integrity but also the nature of plasma membrane breakdown would determine the fate of a cell as well as its ability to elicit an immune response. In this review, we will discuss recent advances in the field of apoptosis, necroptosis and pyroptosis, with an emphasis on the mechanisms underlying plasma membrane changes observed on dying cells and their implication in cell death-elicited immunogenicity.

  18. Are Russian propolis ethanol extracts the future for the prevention of medical and biomedical implant contaminations?

    Science.gov (United States)

    Ambi, Ashwin; Bryan, Julia; Borbon, Katherine; Centeno, Daniel; Liu, Tianchi; Chen, Tung Po; Cattabiani, Thomas; Traba, Christian

    2017-07-01

    Most studies reveal that the mechanism of action of propolis against bacteria is functional rather than structural and is attributed to a synergism between the compounds in the extracts. Propolis is said to inhibit bacterial adherence, division, inhibition of water-insoluble glucan formation, and protein synthesis. However, it has been shown that the mechanism of action of Russian propolis ethanol extracts is structural rather than functional and may be attributed to the metals found in propolis. If the metals found in propolis are removed, cell lysis still occurs and these modified extracts may be used in the prevention of medical and biomedical implant contaminations. The antibacterial activity of metal-free Russian propolis ethanol extracts (MFRPEE) on two biofilm forming bacteria: penicillin-resistant Staphylococcus aureus and Escherichia coli was evaluated using MTT and a Live/Dead staining technique. Toxicity studies were conducted on mouse osteoblast (MC-3T3) cells using the same viability assays. In the MTT assay, biofilms were incubated with MTT at 37°C for 30min. After washing, the purple formazan formed inside the bacterial cells was dissolved by SDS and then measured using a microplate reader by setting the detecting and reference wavelengths at 570nm and 630nm, respectively. Live and dead distributions of cells were studied by confocal laser scanning microscopy. Complete biofilm inactivation was observed when biofilms were treated for 40h with 2µg/ml of MFRPEE. Results indicate that the metals present in propolis possess antibacterial activity, but do not have an essential role in the antibacterial mechanism of action. Additionally, the same concentration of metals found in propolis samples, were toxic to tissue cells. Comparable to samples with metals, metal free samples caused damage to the cell membrane structures of both bacterial species, resulting in cell lysis. Results suggest that the structural mechanism of action of Russian propolis ethanol

  19. Capillary electrophoresis with capacitively coupled contactless conductivity detection: A universal tool for the determination of supported liquid membrane selectivity in electromembrane extraction of complex samples

    Czech Academy of Sciences Publication Activity Database

    Kubáň, Pavel; Boček, Petr

    2012-01-01

    Roč. 1267, SI (2012), s. 96-101 ISSN 0021-9673 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : supported liquid membranes * selectivity measurements * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.612, year: 2012

  20. Supported liquid membrane extraction coupled in-line to commercial capillary electrophoresis for rapid determination of formate in undiluted blood samples

    Czech Academy of Sciences Publication Activity Database

    Pantůčková, Pavla; Kubáň, Pavel; Boček, Petr

    2013-01-01

    Roč. 1299, JUL (2013), s. 33-39 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA13-05762S Institutional support: RVO:68081715 Keywords : capillary electrophoresis * supported liquid membranes * methanol intoxication Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 4.258, year: 2013

  1. A disposable bacterial lysis cartridge (BLC) suitable for an in situ water-borne pathogen detection system.

    Science.gov (United States)

    Lee, Eun-Hee; Lim, Hyun Jeong; Son, Ahjeong; Chua, Beelee

    2015-11-21

    We constructed a disposable bacterial lysis cartridge (BLC) suitable for an in situ pathogen detection system. It had an in-built micro corona discharge based ozone generator that provided ozone for cell lysis. Using a custom sample handling platform, its performance was evaluated with a Gram-positive bacterium of Bacillus subtilis. It was capable of achieving a similar degree of lysis as a commercial ultrasonic dismembrator with a P-1 microprobe in 10 min at an air pump flow rate of 29.4 ml min(-1) and an ozone generator operating voltage of 1600 V. The lysing duration could be significantly reduced to 5 min by increasing the air pump flow rate and the ozone generator operating voltage as well as by the addition of sodium dodecyl sulfate (SDS).

  2. Effects of short-term restraint stress on leukocyte counts, lymphocyte proliferation and lysis of erythrocytes in gilts.

    Science.gov (United States)

    Roozen, A W; Magnusson, U

    1996-10-01

    The effects of short-term restraint stress on leukocyte counts, lymphocyte proliferation and lysis of erythrocytes were studied in six gilts. A catheter was inserted into the jugular vein and two blood samples were collected before the onset of stress. Thereafter a hog snare was applied and blood samples were collected at 0.5, 2, and 3.5 min after the start of snaring. Neither the total WBC number, nor the total number of lymphocytes, or the total number of polymorphonuclear leukocytes changed significantly throughout the study. This was also true for the degree of intravasal lysis of erythrocytes. In whole blood cultures stimulated with pokeweed mitogen, an increase (P immunity but not the leukocyte count nor lysis of erythrocytes in pigs.

  3. The susceptibility to cytotoxic T lymphocyte mediated lysis of chemically induced sarcomas from immunodeficient and normal mice

    DEFF Research Database (Denmark)

    Svane, I M; Engel, A M; Thomsen, Allan Randrup

    1997-01-01

    the sensitivity to CTL mediated lysis and surface expression of the MHC class I molecule Ld of the tumour cells. Tumour cells incapable of in vitro presentation of viral antigen to specific cytotoxic T cells originated from tumours known from previous experiments to be readily accepted after transplantation...... tested for susceptibility to cytolysis by virus specific cytotoxic T cells. Tumour cells originating from tumours induced in immunocompetent C.B.-17 mice presented virus antigen more efficiently than tumour cells from immunodeficient SCID mice. No significant difference in virus antigen presentation...... was found between tumours from nude and nu/+ BALB/c mice. The sensitivity of target cells from the individual tumours to cytotoxic T lymphocyte (CTL) mediated lysis correlated negatively with their sensitivity to natural killer (NK) cell mediated lysis. There was a positive correlation between...

  4. Two mini-preparation protocols to DNA extraction from plants with ...

    African Journals Online (AJOL)

    Were standardized two previously reported standard plant DNA extraction methods, but improved them on mini preparations to use the samples for population genetic analysis. The combination of CTAB lysis procedure-solvent extraction and DNA column purification (DNeasy plant mini kit modification) enables a faster and ...

  5. Water stability of zeolite imidazolate framework 8 and application to porous membrane-protected micro-solid-phase extraction of polycyclic aromatic hydrocarbons from environmental water samples.

    Science.gov (United States)

    Ge, Dandan; Lee, Hian Kee

    2011-11-25

    Zeolite imidazolate framework 8 (ZIF-8) has permanent porosity, high surface area, hydrophobic property, open metal sites and remarkable water stability. These novel properties characterize the material as being different from other moisture sensitive metal-organic frameworks and endow ZIF-8 with the potential to extract trace analytes from environmental water samples. In the present study, ZIF-8 was synthesized and used as a sorbent for micro-solid-phase extraction of 6 polycyclic aromatic hydrocarbons (PAHs) from environmental water samples for the first time. Parameters influencing the extraction efficiency such as desorption time, extraction time, desorption solvent and salt concentration were investigated. Environmental water samples collected from a local lake were processed using this novel μ-SPE procedure. ZIF-8 proved to be a very efficient extraction sorbent for the extraction of trace analytes from water samples. The limits of detection from gas chromatography-mass spectrometric analysis of PAHs were 0.002-0.012 ng/ml. The linear ranges were 0.1-50 or 0.5-50 ng/ml. The relative standard deviations for five replicates of the extractions were in the range of 2.1-8.5%. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Viral lysis of Phaeocystis pouchetii: implications for algal population dynamics and heterotrophic C, N and P cycling

    DEFF Research Database (Denmark)

    Haaber, Jakob Brandt Borup; Middelboe, Mathias

    2009-01-01

    A model ecosystem with two autotrophic flagellates, Phaeocystis pouchetii and Rhodomonas salina, a virus specific to P. pouchetii (PpV) and bacteria and heterotrophic nanoflagellates was used to investigate effects of viral lysis on algal population dynamics and heterotrophic nitrogen and phospho......A model ecosystem with two autotrophic flagellates, Phaeocystis pouchetii and Rhodomonas salina, a virus specific to P. pouchetii (PpV) and bacteria and heterotrophic nanoflagellates was used to investigate effects of viral lysis on algal population dynamics and heterotrophic nitrogen...

  7. Analysis of five streptokinase formulations using the euglobulin lysis test and the plasminogen activation assay

    Directory of Open Access Journals (Sweden)

    Couto L.T.

    2004-01-01

    Full Text Available Streptokinase, a 47-kDa protein isolated and secreted by most group A, C and G ß-hemolytic streptococci, interacts with and activates human protein plasminogen to form an active complex capable of converting other plasminogen molecules to plasmin. Our objective was to compare five streptokinase formulations commercially available in Brazil in terms of their activity in the in vitro tests of euglobulin clot formation and of the hydrolysis of the plasmin-specific substrate S-2251(TM. Euglobulin lysis time was determined using a 96-well microtiter plate. Initially, human thrombin (10 IU/ml and streptokinase were placed in individual wells, clot formation was initiated by the addition of plasma euglobulin, and turbidity was measured at 340 nm every 30 s. In the second assay, plasminogen activation was measured using the plasmin-specific substrate S-2251(TM. Streptase(TM was used as the reference formulation because it presented the strongest fibrinolytic activity in the euglobulin lysis test. The Unitinase(TM and Solustrep(TM formulations were the weakest, showing about 50% activity compared to the reference formulation. All streptokinases tested activated plasminogen but significant differences were observed. In terms of total S-2251(TM activity per vial, Streptase(TM (75.7 ± 5.0 units and Streptonase(TM (94.7 ± 4.6 units had the highest activity, while Unitinase(TM (31.0 ± 2.4 units and Strek(TM (32.9 ± 3.3 units had the weakest activity. Solustrep(TM (53.3 ± 2.7 units presented intermediate activity. The variations among the different formulations for both euglobulin lysis test and chromogenic substrate hydrolysis correlated with the SDS-PAGE densitometric results for the amount of 47-kDa protein. These data show that the commercially available clinical streptokinase formulations vary significantly in their in vitro activity. Whether these differences have clinical implications needs to be investigated.

  8. Same day identification and full panel antimicrobial susceptibility testing of bacteria from positive blood culture bottles made possible by a combined lysis-filtration method with MALDI-TOF VITEK mass spectrometry and the VITEK2 system.

    Directory of Open Access Journals (Sweden)

    Alexandra Machen

    Full Text Available Rapid identification and antimicrobial susceptibility testing of microorganisms causing bloodstream infections or sepsis have the potential to improve patient care. This proof-of-principle study evaluates the Lysis-Filtration Method for identification as well as antimicrobial susceptibility testing of bacteria directly from positive blood culture bottles in a clinical setting. A total of 100 non-duplicated positive blood cultures were tested and 1012 microorganism-antimicrobial combinations were assessed. An aliquot of non-charcoal blood culture broth was incubated with lysis buffer briefly before being filtered and washed. Microorganisms recovered from the filter membrane were first identified by using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight VITEK® Mass Spectrometry (VITEK MS. After quick identification from VITEK MS, filtered microorganisms were inoculated to VITEK®2 system for full panel antimicrobial susceptibility testing analysis. Of 100 bottles tested, the VITEK MS resulted in 94.0% correct organism identification to the species level. Compared to the conventional antimicrobial susceptibility testing methods, direct antimicrobial susceptibility testing from VITEK®2 resulted in 93.5% (946/1012 category agreement of antimicrobials tested, with 3.6% (36/1012 minor error, 1.7% (7/1012 major error, and 1.3% (13/1012 very major error of antimicrobials. The average time to identification and antimicrobial susceptibility testing was 11.4 hours by using the Lysis-Filtration method for both VITEK MS and VITEK®2 compared to 56.3 hours by using conventional methods (p<0.00001. Thus, the same-day results of microorganism identification and antimicrobial susceptibility testing directly from positive blood culture can be achieved and can be used for appropriate antibiotic therapy and antibiotic stewardship.

  9. Same Day Identification and Full Panel Antimicrobial Susceptibility Testing of Bacteria from Positive Blood Culture Bottles Made Possible by a Combined Lysis-Filtration Method with MALDI-TOF VITEK Mass Spectrometry and the VITEK2 System

    Science.gov (United States)

    Machen, Alexandra; Drake, Tim; Wang, Yun F. (Wayne)

    2014-01-01

    Rapid identification and antimicrobial susceptibility testing of microorganisms causing bloodstream infections or sepsis have the potential to improve patient care. This proof-of-principle study evaluates the Lysis-Filtration Method for identification as well as antimicrobial susceptibility testing of bacteria directly from positive blood culture bottles in a clinical setting. A total of 100 non-duplicated positive blood cultures were tested and 1012 microorganism-antimicrobial combinations were assessed. An aliquot of non-charcoal blood culture broth was incubated with lysis buffer briefly before being filtered and washed. Microorganisms recovered from the filter membrane were first identified by using Matrix-Assisted Laser Desorption/Ionization Time-of-Flight VITEK® Mass Spectrometry (VITEK MS). After quick identification from VITEK MS, filtered microorganisms were inoculated to VITEK®2 system for full panel antimicrobial susceptibility testing analysis. Of 100 bottles tested, the VITEK MS resulted in 94.0% correct organism identification to the species level. Compared to the conventional antimicrobial susceptibility testing methods, direct antimicrobial susceptibility testing from VITEK®2 resulted in 93.5% (946/1012) category agreement of antimicrobials tested, with 3.6% (36/1012) minor error, 1.7% (7/1012) major error, and 1.3% (13/1012) very major error of antimicrobials. The average time to identification and antimicrobial susceptibility testing was 11.4 hours by using the Lysis-Filtration method for both VITEK MS and VITEK®2 compared to 56.3 hours by using conventional methods (p<0.00001). Thus, the same-day results of microorganism identification and antimicrobial susceptibility testing directly from positive blood culture can be achieved and can be used for appropriate antibiotic therapy and antibiotic stewardship. PMID:24551067

  10. Extraction of Active Enzymes from "Hard-to-Break-Cells"

    DEFF Research Database (Denmark)

    Ottaviani, Alessio; Tesauro, Cinzia; Fjelstrup, S

    We present the utilization of a rolling circle amplification (RCA) based assay to investigate the extraction efficiency of active enzymes from a class of “hard-to-break” cells, yeast Saccaramyces cerevisiae. Current analyses of microorganisms, such as pathogenic bacteria, parasites or particular...... life stages of microorganisms (e.g. spores from bacteria or fungi) is hampered by the lack of efficient lysis protocols that preserve the activity and integrity of the cellular content. Presented herein is a flexible scheme to screen lysis protocols for active enzyme extraction. We also report a gentle...... yet effective approach for extraction of active enzymes by entrapping cells in microdroplets. Combined effort of optimized extraction protocols and effective analytical approaches is expected to generate impact in future disease diagnosis and environmental safety....

  11. Antimicrobial Actions of Hexachlorophene: Lysis and Fixation of Bacterial Protoplasts1

    Science.gov (United States)

    Corner, Thomas R.; Joswick, H. L.; Silvernale, J. N.; Gerhardt, Philipp

    1971-01-01

    Hexachlorophene was found to be both a lytic and a fixative agent for protoplasts isolated from Bacillus megaterium. Concentrations of 50 to 100 μg of drug per mg of original cell dry weight were required to lyse 4.4 × 109 protoplasts (2 mg of original cell dry weight). At higher drug concentrations, protoplasts became fixed against osmotic stress and reduced in sensitivity to disruption by n-butanol. Lower drug concentrations caused proportionate lysis in the protoplast population. Intact cells lost the ability to become plasmolyzed at these same hexachlorophene concentrations. Nonplasmolyzed, drug-treated cells were resistant to the action of lysozyme, whereas plasmolyzed, drug-treated cells were sensitive. But the sensitivity of isolated cell walls to lysozyme digestion was not markedly altered by hexachlorophene treatment. These effects appeared to be secondary in the killing of cells by hexachlorophene because they occurred at concentrations higher than the minimum lethal concentration. PMID:5001202

  12. Dual Targeting of Cell Wall Precursors by Teixobactin Leads to Cell Lysis

    Science.gov (United States)

    Homma, Tomoyuki; Nuxoll, Austin; Gandt, Autumn Brown; Ebner, Patrick; Engels, Ina; Schneider, Tanja; Götz, Friedrich; Lewis, Kim

    2016-01-01

    Teixobactin represents the first member of a newly discovered class of antibiotics that act through inhibition of cell wall synthesis. Teixobactin binds multiple bactoprenol-coupled cell wall precursors, inhibiting both peptidoglycan and teichoic acid synthesis. Here, we show that the impressive bactericidal activity of teixobactin is due to the synergistic inhibition of both targets, resulting in cell wall damage, delocalization of autolysins, and subsequent cell lysis. We also find that teixobactin does not bind mature peptidoglycan, further increasing its activity at high cell densities and against vancomycin-intermediate Staphylococcus aureus (VISA) isolates with thickened peptidoglycan layers. These findings add to the attractiveness of teixobactin as a potential therapeutic agent for the treatment of infection caused by antibiotic-resistant Gram-positive pathogens. PMID:27550357

  13. Biological variation in tPA-induced plasma clot lysis time.

    Science.gov (United States)

    Talens, Simone; Malfliet, Joyce J M C; Rudež, Goran; Spronk, Henri M H; Janssen, Nicole A H; Meijer, Piet; Kluft, Cornelis; de Maat, Moniek P M; Rijken, Dingeman C

    2012-10-01

    Hypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Sufficient information about assay variation and biological variation in CLT is not yet available. Thus, this study aimed to determine the analytical, within-subject and between-subject variation in CLT. We collected blood samples from 40 healthy individuals throughout a period of one year (average 11.8 visits) and determined the CLT of each plasma sample in duplicate. The mean (± SD) CLT was 83.8 (± 11.1) minutes. The coefficients of variation for total variation, analytical variation, within-subject variation and between-subject variation were 13.4%, 2.6%, 8.2% and 10.2%, respectively. One measurement can estimate the CLT that does not deviate more than 20% from its true value. The contribution of analytical variation to the within-subject variation was 5.0%, the index of individuality was 0.84 and the reference change value was 23.8%. The CLT was longer in the morning compared to the afternoon and was slightly longer in older individuals (> 40 years) compared to younger (≤40 years) individuals. There was no seasonal variation in CLT and no association with air pollution. CLT correlated weakly with fibrinogen, C-reactive protein, prothrombin time and thrombin generation. This study provides insight into the biological variation of CLT, which can be used in future studies testing CLT as a potential risk factor for thrombosis.

  14. Stabilizing Additives Added during Cell Lysis Aid in the Solubilization of Recombinant Proteins

    Science.gov (United States)

    Leibly, David J.; Nguyen, Trang Nhu; Kao, Louis T.; Hewitt, Stephen N.; Barrett, Lynn K.; Van Voorhis, Wesley C.

    2012-01-01

    Insoluble recombinant proteins are a major issue for both structural genomics and enzymology research. Greater than 30% of recombinant proteins expressed in Escherichia coli (E. coli) appear to be insoluble. The prevailing view is that insolubly expressed proteins cannot be easily solubilized, and are usually sequestered into inclusion bodies. However, we hypothesize that small molecules added during the cell lysis stage can yield soluble protein from insoluble protein previously screened without additives or ligands. We present a novel screening method that utilized 144 additive conditions to increase the solubility of recombinant proteins expressed in E. coli. These selected additives are natural ligands, detergents, salts, buffers, and chemicals that have been shown to increase the stability of proteins in vivo. We present the methods used for this additive solubility screen and detailed results for 41 potential drug target recombinant proteins from infectious organisms. Increased solubility was observed for 80% of the recombinant proteins during the primary and secondary screening of lysis with the additives; that is 33 of 41 target proteins had increased solubility compared with no additive controls. Eleven additives (trehalose, glycine betaine, mannitol, L-Arginine, potassium citrate, CuCl2, proline, xylitol, NDSB 201, CTAB and K2PO4) solubilized more than one of the 41 proteins; these additives can be easily screened to increase protein solubility. Large-scale purifications were attempted for 15 of the proteins using the additives identified and eight (40%) were prepared for crystallization trials during the first purification attempt. Thus, this protocol allowed us to recover about a third of seemingly insoluble proteins for crystallography and structure determination. If recombinant proteins are required in smaller quantities or less purity, the final success rate may be even higher. PMID:23285060

  15. Comparative analysis shows that bacterivory, not viral lysis, controls the abundance of heterotrophic prokaryotic plankton.

    Science.gov (United States)

    Pedrós-Alió; Calderón-Paz; Gasol

    2000-04-01

    Empirical models derived from literature data were used to compare the factors controlling prokaryotic abundance (PN) and prokaryotic heterotrophic production (PHP) in solar salterns. These empirical relationships were generated as multiple linear regressions with PN or PHP as dependent variables, while the independent variables were chosen to reflect the likely sources of organic matter, inorganic nutrients and temperature. These variables were then measured in solar salterns and the predictions made by the general relationships were compared to actual saltern values of PN and PHP. Saltern ponds of salinity higher than 100 per thousand departed significantly from the general relationships, while the ponds of salinity lower than 100 per thousand fitted well within the range of values predicted by the general models. The most likely explanation for the discrepancy of the former was the absence of bacterivory. This hypothesis was tested with data from other very different aquatic systems: karstic lakes with anaerobic hypolimnia and two marine areas in the Mediterranean and the Southern Ocean. The anoxic regions of karstic lakes departed significantly from the predictions of the general model, while the oxic layers conformed to the predictions. As in the case of salterns, this difference could be explained by the presence of significant predation in the oxic, but not in the anoxic, layers of these lakes. Finally, two marine areas with similar predation pressure on prokaryotes but very different impacts of viral lysis were tested. In all cases, PN values conformed to the predictions, suggesting that lysis due to viruses is not the main factor controlling PN in aquatic systems, which is more likely to be determined by the balance between bacterivory and resource supply. The present work also demonstrates the usefulness of empirical comparative analyses to generate predictions and to draw inferences on the functioning of microbial communities.

  16. Prediction of recurrent venous thromboembolism by clot lysis time: a prospective cohort study.

    Science.gov (United States)

    Traby, Ludwig; Kollars, Marietta; Eischer, Lisbeth; Eichinger, Sabine; Kyrle, Paul A

    2012-01-01

    Venous thromboembolism (VTE) is a chronic disease, which tends to recur. Whether an abnormal fibrinolytic system is associated with an increased risk of VTE is unclear. We assessed the relationship between fibrinolytic capacity (reflected by clot lysis time [CLT]) and risk of recurrent VTE. We followed 704 patients (378 women; mean age 48 yrs) with a first unprovoked VTE for an average of 46 months after anticoagulation withdrawal. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, cancer, homozygosity for factor V Leiden or prothrombin mutation, or requirement for indefinite anticoagulation were excluded. Study endpoint was symptomatic recurrent VTE. For measurement of CLT, a tissue factor-induced clot was lysed by adding tissue-type plasminogen activator. Time between clot formation and lysis was determined by measuring the turbidity. 135 (19%) patients had recurrent VTE. For each increase in CLT of 10 minutes, the crude relative risk (RR) of recurrence was 1.13 (95% CI 1.02-1.25; p = 0.02) and was 1.08 (95% CI 0.98-1.20; p = 0.13) after adjustment for age and sex. For women only, the adjusted RR was 1.14 (95% CI, 0.91-1.42, p = 0.22) for each increase in CLT of 10 minutes. CLT values in the 4(th) quartile of the female patient population, as compared to values in the 1(st) quartile, conferred a risk of recurrence of 3.28 (95% CI, 1.07-10.05; p = 0.04). No association between CLT and recurrence risk was found in men. Hypofibrinolysis as assessed by CLT confers a moderate increase in the risk of recurrent VTE. A weak association between CLT and risk of recurrence was found in women only.

  17. Prediction of recurrent venous thromboembolism by clot lysis time: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Ludwig Traby

    Full Text Available Venous thromboembolism (VTE is a chronic disease, which tends to recur. Whether an abnormal fibrinolytic system is associated with an increased risk of VTE is unclear. We assessed the relationship between fibrinolytic capacity (reflected by clot lysis time [CLT] and risk of recurrent VTE. We followed 704 patients (378 women; mean age 48 yrs with a first unprovoked VTE for an average of 46 months after anticoagulation withdrawal. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, cancer, homozygosity for factor V Leiden or prothrombin mutation, or requirement for indefinite anticoagulation were excluded. Study endpoint was symptomatic recurrent VTE. For measurement of CLT, a tissue factor-induced clot was lysed by adding tissue-type plasminogen activator. Time between clot formation and lysis was determined by measuring the turbidity. 135 (19% patients had recurrent VTE. For each increase in CLT of 10 minutes, the crude relative risk (RR of recurrence was 1.13 (95% CI 1.02-1.25; p = 0.02 and was 1.08 (95% CI 0.98-1.20; p = 0.13 after adjustment for age and sex. For women only, the adjusted RR was 1.14 (95% CI, 0.91-1.42, p = 0.22 for each increase in CLT of 10 minutes. CLT values in the 4(th quartile of the female patient population, as compared to values in the 1(st quartile, conferred a risk of recurrence of 3.28 (95% CI, 1.07-10.05; p = 0.04. No association between CLT and recurrence risk was found in men. Hypofibrinolysis as assessed by CLT confers a moderate increase in the risk of recurrent VTE. A weak association between CLT and risk of recurrence was found in women only.

  18. Stabilizing additives added during cell lysis aid in the solubilization of recombinant proteins.

    Directory of Open Access Journals (Sweden)

    David J Leibly

    Full Text Available Insoluble recombinant proteins are a major issue for both structural genomics and enzymology research. Greater than 30% of recombinant proteins expressed in Escherichia coli (E. coli appear to be insoluble. The prevailing view is that insolubly expressed proteins cannot be easily solubilized, and are usually sequestered into inclusion bodies. However, we hypothesize that small molecules added during the cell lysis stage can yield soluble protein from insoluble protein previously screened without additives or ligands. We present a novel screening method that utilized 144 additive conditions to increase the solubility of recombinant proteins expressed in E. coli. These selected additives are natural ligands, detergents, salts, buffers, and chemicals that have been shown to increase the stability of proteins in vivo. We present the methods used for this additive solubility screen and detailed results for 41 potential drug target recombinant proteins from infectious organisms. Increased solubility was observed for 80% of the recombinant proteins during the primary and secondary screening of lysis with the additives; that is 33 of 41 target proteins had increased solubility compared with no additive controls. Eleven additives (trehalose, glycine betaine, mannitol, L-Arginine, potassium citrate, CuCl(2, proline, xylitol, NDSB 201, CTAB and K(2PO(4 solubilized more than one of the 41 proteins; these additives can be easily screened to increase protein solubility. Large-scale purifications were attempted for 15 of the proteins using the additives identified and eight (40% were prepared for crystallization trials during the first purification attempt. Thus, this protocol allowed us to recover about a third of seemingly insoluble proteins for crystallography and structure determination. If recombinant proteins are required in smaller quantities or less purity, the final success rate may be even higher.

  19. Fluorescence interference contrast based approach to study real time interaction of melittin with plasma membranes

    Science.gov (United States)

    Gupta, Sharad; Gui, Dong; Zandi, Roya; Gill, Sarjeet; Mohideen, Umar

    2014-03-01

    Melittin is an anti-bacterial and hemolytic toxic peptide found in bee venom. Cell lysis behavior of peptides has been widely investigated, but the exact interaction mechanism of lytic peptides with lipid membranes and its constituents has not been understood completely. In this paper we study the melittin interaction with lipid plasma membranes in real time using non-invasive and non-contact fluorescence interference contrast microscopy (FLIC). Particularly the interaction of melittin with plasma membranes was studied in a controlled molecular environment, where these plasma membrane were composed of saturated lipid, 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC) and unsaturated lipid, 1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC) with and without cholesterol. We found out that melittin starts to form nanometer size pores in the plasma membranes shortly after interacting with membranes. But the addition of cholesterol in plasma membrane slows down the pore formation process. Our results show that inclusion of cholesterol to the plasma membranes make them more resilient towards pore formation and lysis of membrane.

  20. Optimizing factors influencing DNA extraction from fresh whole avian ...

    African Journals Online (AJOL)

    Administrator

    2007-02-19

    Feb 19, 2007 ... quantity and quality of DNA extracted from various volumes of avian blood. Blood samples were collected in EDTA and swiftly transferred to a laboratory for DNA extraction. The lysis buffer used had composition 5 M NaCl, 1 M Tris (pH=8.0), 0.5 M EDTA and20% SDS. The effect of various levels for each.

  1. Membranous nephropathy

    Science.gov (United States)

    ... check for hepatitis B, hepatitis C, and syphilis Complement levels Cryoglobulin test Treatment The goal of treatment ... not as helpful for people with membranous nephropathy. Medicines used treat membranous nephropathy include: Angiotensin-converting enzyme ( ...

  2. Sulfolobus Turreted Icosahedral Virus c92 Protein Responsible for the Formation of Pyramid-Like Cellular Lysis Structures

    DEFF Research Database (Denmark)

    Snyder, Jamie C; Brumfield, Susan K; Peng, Nan

    2011-01-01

    Host cells infected by Sulfolobus turreted icosahedral virus (STIV) have been shown to produce unusual pyramid-like structures on the cell surface. These structures represent a virus-induced lysis mechanism that is present in Archaea and appears to be distinct from the holin/endolysin system...

  3. Rearrangements of the fibrin network and spatial distribution of fibrinolytic components during plasma clot lysis: Study with confocal microscopy

    NARCIS (Netherlands)

    Sakharov, D.V.; Nagelkerkel, J.F.; Rijken, D.C.

    1996-01-01

    Binding of components of the fibrinolytic system to fibrin is important for the regulation of fibrinolysis. In this study, decomposition of the fibrin network and binding of plasminogen and plasminogen activators (PAs) to fibrin during lysis of a plasma clot were investigated with confocal

  4. High expression of the c-myc oncogene renders melanoma cells prone to lysis by natural killer cells

    NARCIS (Netherlands)

    Versteeg, R.; Peltenburg, L. T.; Plomp, A. C.; Schrier, P. I.

    1989-01-01

    NK cells kill a wide variety of tumor cells, but usually leave normal cells intact. It was earlier reported that low class I HLA expression can be one of the factors that render target cells relatively susceptible to NK lysis. In this contribution, we show that in human melanomas the class I HLA

  5. Comparison of the efficiency of different methods for the lysis of cells in lab-on-chip systems

    NARCIS (Netherlands)

    Röser, T.; Drese, K.S.; Fütterer, X.; Germar, F. von; Hansen-Hagge, T.E.; Ritzi, M.; Bullema, J.E.; Bolt, P.J.

    2007-01-01

    Quantitative or qualitative examination of DNA has enormous impact on medical, forensic, or genealogical, analysis. The macro as well as micro world knows a panel of different methods for cell lysis that has to happen prior to the purification of the DNA. To our knowledge the efficiency of those

  6. Influence of serum extraction from the culture medium and of sublethal X-ray irradiation upon microvilli and invaginations of the membrane of Ehrlich ascites tumor cells in monolayer culture

    Energy Technology Data Exchange (ETDEWEB)

    Laudenbach, G.; Pfab, R.; Hess, F.; Schachtschabel, D.O.

    1984-09-01

    In order to find out modifications of microvilli and invaginations, the cellular surfaces of Ehrlich ascites tumor cells in monolayer culture (basal medium of Eagle + 10% fetal calf serum) were investigated with the aid of electron-microscopic cross-sections. The tumor cells had been cultured without serum 24 hours prior to investigation or irradiated with 2 Gy. Morphometric evaluation after cell culture in a serum-free medium showed a reduced number of microvilli and a diminution of sections of microvilli. As already described before, a reduction of cell proliferation, of the microtubule-microfilament system, and of the endocytosis activity occurs under these serum-free conditions. The number of invaginations (related to a constant membrane part) was reduced by nearly 50% after serum extraction. Similarly to serum extraction, sublethal X-ray irradiation reduced the sections of microvilli, whereas the number of microvilli increased slightly. Contrary to the effect of serum extraction, the irradiated cells showed twice as many invaginations as the non-irradiated control cells. These differences in the surface structures are interpreted as a result of modified growth stimulations (+- serum) and radiogenic reparation processes.

  7. Rapid and simple pretreatment of human body fluids using electromembrane extraction across supported liquid membrane for capillary electrophoretic determination of lithium

    Czech Academy of Sciences Publication Activity Database

    Strieglerová, Lenka; Kubáň, Pavel; Boček, Petr

    2011-01-01

    Roč. 32, č. 10 (2011), s. 1182-1189 ISSN 0173-0835 R&D Projects: GA ČR GAP206/10/1219 Institutional research plan: CEZ:AV0Z40310501 Keywords : electromembrane extraction * biological samples * capillary electrophoresis Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.303, year: 2011

  8. Application of a macrocyclic compound, bambus[6]uril, in tailor-made liquid membranes for highly selective electromembrane extractions of inorganic anions

    Czech Academy of Sciences Publication Activity Database

    Šlampová, Andrea; Šindelář, V.; Kubáň, Pavel

    2017-01-01

    Roč. 950, JAN (2017), s. 49-56 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA16-09135S Institutional support: RVO:68081715 Keywords : bambus[6]uril * electromembrane extraction selectivity * inorganic anions Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

  9. Membrane Biophysics

    CERN Document Server

    Ashrafuzzaman, Mohammad

    2013-01-01

    Physics, mathematics and chemistry all play a vital role in understanding the true nature and functioning of biological membranes, key elements of living processes. Besides simple spectroscopic observations and electrical measurements of membranes we address in this book the phenomena of coexistence and independent existence of different membrane components using various theoretical approaches. This treatment will be helpful for readers who want to understand biological processes by applying both simple observations and fundamental scientific analysis. It provides a deep understanding of the causes and effects of processes inside membranes, and will thus eventually open new doors for high-level pharmaceutical approaches towards fighting membrane- and cell-related diseases.

  10. The room temperature preservation of filtered environmental DNA samples and assimilation into a phenol-chloroform-isoamyl alcohol DNA extraction.

    Science.gov (United States)

    Renshaw, Mark A; Olds, Brett P; Jerde, Christopher L; McVeigh, Margaret M; Lodge, David M

    2015-01-01

    Current research targeting filtered macrobial environmental DNA (eDNA) often relies upon cold ambient temperatures at various stages, including the transport of water samples from the field to the laboratory and the storage of water and/or filtered samples in the laboratory. This poses practical limitations for field collections in locations where refrigeration and frozen storage is difficult or where samples must be transported long distances for further processing and screening. This study demonstrates the successful preservation of eDNA at room temperature (20 °C) in two lysis buffers, CTAB and Longmire's, over a 2-week period of time. Moreover, the preserved eDNA samples were seamlessly integrated into a phenol-chloroform-isoamyl alcohol (PCI) DNA extraction protocol. The successful application of the eDNA extraction to multiple filter membrane types suggests the methods evaluated here may be broadly applied in future eDNA research. Our results also suggest that for many kinds of studies recently reported on macrobial eDNA, detection probabilities could have been increased, and at a lower cost, by utilizing the Longmire's preservation buffer with a PCI DNA extraction. © 2014 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

  11. The room temperature preservation of filtered environmental DNA samples and assimilation into a phenol–chloroform–isoamyl alcohol DNA extraction

    Science.gov (United States)

    Renshaw, Mark A; Olds, Brett P; Jerde, Christopher L; McVeigh, Margaret M; Lodge, David M

    2015-01-01

    Current research targeting filtered macrobial environmental DNA (eDNA) often relies upon cold ambient temperatures at various stages, including the transport of water samples from the field to the laboratory and the storage of water and/or filtered samples in the laboratory. This poses practical limitations for field collections in locations where refrigeration and frozen storage is difficult or where samples must be transported long distances for further processing and screening. This study demonstrates the successful preservation of eDNA at room temperature (20 °C) in two lysis buffers, CTAB and Longmire's, over a 2-week period of time. Moreover, the preserved eDNA samples were seamlessly integrated into a phenol–chloroform–isoamyl alcohol (PCI) DNA extraction protocol. The successful application of the eDNA extraction to multiple filter membrane types suggests the methods evaluated here may be broadly applied in future eDNA research. Our results also suggest that for many kinds of studies recently reported on macrobial eDNA, detection probabilities could have been increased, and at a lower cost, by utilizing the Longmire's preservation buffer with a PCI DNA extraction. PMID:24834966

  12. Irreversible AE1 tyrosine phosphorylation leads to membrane vesiculation in G6PD deficient red cells.

    Directory of Open Access Journals (Sweden)

    Antonella Pantaleo

    Full Text Available BACKGROUND: While G6PD deficiency is one of the major causes of acute hemolytic anemia, the membrane changes leading to red cell lysis have not been extensively studied. New findings concerning the mechanisms of G6PD deficient red cell destruction may facilitate our understanding of the large individual variations in susceptibility to pro-oxidant compounds and aid the prediction of the hemolytic activity of new drugs. METHODOLOGY/PRINCIPAL FINDINGS: Our results show that treatment of G6PD deficient red cells with diamide (0.25 mM or divicine (0.5 mM causes: (1 an increase in the oxidation and tyrosine phosphorylation of AE1; (2 progressive recruitment of phosphorylated AE1 in large membrane complexes which also contain hemichromes; (3 parallel red cell lysis and a massive release of vesicles containing hemichromes. We have observed that inhibition of AE1 phosphorylation by Syk kinase inhibitors prevented its clustering and the membrane vesiculation while increases in AE1 phosphorylation by tyrosine phosphatase inhibitors increased both red cell lysis and vesiculation rates. In control RBCs we observed only transient AE1 phosphorylation. CONCLUSIONS/SIGNIFICANCE: Collectively, our findings indicate that persistent tyrosine phosphorylation produces extensive membrane destabilization leading to the loss of vesicles which contain hemichromes. The proposed mechanism of hemolysis may be applied to other hemolytic diseases characterized by the accumulation of hemoglobin denaturation products.

  13. Aqueous Cinnamon Extract (ACE-c) from the bark of Cinnamomum cassia causes apoptosis in human cervical cancer cell line (SiHa) through loss of mitochondrial membrane potential

    International Nuclear Information System (INIS)

    Koppikar, Soumya J; Choudhari, Amit S; Suryavanshi, Snehal A; Kumari, Shweta; Chattopadhyay, Samit; Kaul-Ghanekar, Ruchika

    2010-01-01

    Chemoprevention, which includes the use of synthetic or natural agents (alone or in combination) to block the development of cancer in human beings, is an extremely promising strategy for cancer prevention. Cinnamon is one of the most widely used herbal medicines with diverse biological activities including anti-tumor activity. In the present study, we have reported the anti-neoplastic activity of cinnamon in cervical cancer cell line, SiHa. The aqueous cinnamon extract (ACE-c) was analyzed for its cinnamaldehyde content by HPTLC analysis. The polyphenol content of ACE-c was measured by Folin-Ciocalteau method. Cytotoxicity analysis was performed by MTT assay. We studied the effect of cinnamon on growth kinetics by performing growth curve, colony formation and soft agar assays. The cells treated with ACE-c were analyzed for wound healing assay as well as for matrix metalloproteinase-2 (MMP-2) expression at mRNA and protein level by RT-PCR and zymography, respectively. Her-2 protein expression was analyzed in the control and ACE-c treated samples by immunoblotting as well as confocal microscopy. Apoptosis studies and calcium signaling assays were analyzed by FACS. Loss of mitochondrial membrane potential (Δψ m ) in cinnamon treated cells was studied by JC-1 staining and analyzed by confocal microscopy as well as FACS. Cinnamon alters the growth kinetics of SiHa cells in a dose-dependent manner. Cells treated with ACE-c exhibited reduced number of colonies compared to the control cells. The treated cells exhibited reduced migration potential that could be explained due to downregulation of MMP-2 expression. Interestingly, the expression of Her-2 oncoprotein was significantly reduced in the presence of ACE-c. Cinnamon extract induced apoptosis in the cervical cancer cells through increase in intracellular calcium signaling as well as loss of mitochondrial membrane potential. Cinnamon could be used as a potent chemopreventive drug in cervical cancer

  14. Cell-free system for synthesizing membrane proteins cell free method for synthesizing membrane proteins

    Science.gov (United States)

    Laible, Philip D; Hanson, Deborah K

    2013-06-04

    The invention provides an in vitro method for producing proteins, membrane proteins, membrane-associated proteins, and soluble proteins that interact with membrane-associated proteins for assembly into an oligomeric complex or that require association with a membrane for proper folding. The method comprises, supplying intracytoplasmic membranes from organisms; modifying protein composition of intracytoplasmic membranes from organism by modifying DNA to delete genes encoding functions of the organism not associated with the formation of the intracytoplasmic membranes; generating appropriate DNA or RNA templates that encode the target protein; and mixing the intracytoplasmic membranes with the template and a transcription/translation-competent cellular extract to cause simultaneous production of the membrane proteins and encapsulation of the membrane proteins within the intracytoplasmic membranes.

  15. Immunological characterization of a basement membrane-specific chondroitin sulfate proteoglycan

    DEFF Research Database (Denmark)

    McCarthy, K J; Accavitti, M A; Couchman, J R

    1989-01-01

    Reichert's membrane, an extraembryonic membrane present in developing rodents, has been proposed as an in vivo model for the study of basement membranes. We have used this membrane as a source for isolation of basement membrane proteoglycans. Reichert's membranes were extracted in a guanidine/3-[...

  16. Methods for microbial DNA extraction from soil for PCR amplification

    Directory of Open Access Journals (Sweden)

    Yeates C

    1998-01-01

    Full Text Available Amplification of DNA from soil is often inhibited by co-purified contaminants. A rapid, inexpensive, large-scale DNA extraction method involving minimal purification has been developed that is applicable to various soil types (1. DNA is also suitable for PCR amplification using various DNA targets. DNA was extracted from 100g of soil using direct lysis with glass beads and SDS followed by potassium acetate precipitation, polyethylene glycol precipitation, phenol extraction and isopropanol precipitation. This method was compared to other DNA extraction methods with regard to DNA purity and size.

  17. Extraction and Determination of Trace Copper (II Using Octadecyl Silica Membrane Disks Modified 1-(2-Pyridyl Azo 2-Naphtol(Pan in Water Samples and Paraffin-Embedded Tissues from Liver Loggerhead Turtles Specimens by FAAS

    Directory of Open Access Journals (Sweden)

    A. Moghimi

    2012-07-01

    Full Text Available A simple and reproducible method for the rapid extraction and determination of trace amounts of copper(II ions using octadecyl-bonded silica membrane disks modified by 1-(2-Pyridyl Azo2-Naphtol(PANand Atomic Absorption Spectrometry was presented. The method was based on complex formation on the surface of the ENVI-18 DISKTM disks followed by stripping of the retained species by minimum amounts of appropriate organic solvents. The elution was efficient and quantitative. The effect of potential interfering ions, pH, ligand amount, stripping solvent, and sample flow rate were also investigated. Under the optimal experimental conditions, the break-through volume was found to about 1000mL providing a preconcentration factor of 500. In the present study, we reported the application of preconcentration techniques still continues increasingly for trace metal determinations by flame atomic absorption spectrometry (FAAS for quantification of Cu in Formalin-fixed paraffin-embedded (FFPE tissues from Liver loggerhead turtles. The maximum capacity of the disks was found to be 389± 4 µg for Cu2+.The limit of detection of the proposed method was 5ng per 1000mL.The method was applied to the extraction and recovery of copper in different water samples.

  18. Large-scale clinical comparison of the lysis-centrifugation and radiometric systems for blood culture

    International Nuclear Information System (INIS)

    Brannon, P.; Kiehn, T.E.

    1985-01-01

    The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours and Co., Inc., Wilmington, Del.) was compared with the BACTEC radiometric method (Johnston Laboratories, Inc., Towson, Md.) with 6B and 7D broth media for the recovery of bacteria and yeasts. From 11,000 blood cultures, 1,174 clinically significant organisms were isolated. The Isolator system recovered significantly more total organisms, members of the family Enterobacteriaceae, Staphylococcus spp., and yeasts. The BACTEC system recovered significantly more Pseudomonas spp., Streptococcus spp., and anaerobes. Of the Isolator colony counts, 87% measured less than 11 CFU/ml of blood. Organisms, on an average, were detected the same day from each of the two culture systems. Only 13 of the 975 BACTEC isolates (0.01%) were recovered by subculture of growth-index-negative bottles, and 12 of the 13 were detected in another broth blood culture taken within 24 h. Contaminants were recovered from 4.8% of the Isolator 10 and 2.3% of the BACTEC cultures

  19. Features of target cell lysis by class I and class II MHC restricted cytolytic T lymphocytes

    International Nuclear Information System (INIS)

    Maimone, M.M.; Morrison, L.A.; Braciale, V.L.; Braciale, T.J.

    1986-01-01

    The lytic activity of influenza virus-specific muvine cytolytic T lymphocyte (CTL) clones that are restricted by either H-2K/D (class I) or H-2I (class II) major histocompatibility (MHC) locus products was compared on an influenza virus-infected target cell expressing both K/D and I locus products. With the use of two in vitro measurements of cytotoxicity, conventional 51 Cr release, and detergent-releasable radiolabeled DNA (as a measure of nuclear disintegration in the early post-lethal hit period), the authors found no difference between class I and class II MHC-restricted CTL in the kinetics of target cell destruction. In addition, class II MHC-restricted antiviral CTL failed to show any lysis of radiolabeled bystander cells. Killing of labeled specific targets by these class II MHC-restricted CTL was also efficiently inhibited by unlabeled specific competitor cells in a cold target inhibition assay. In sum, these data suggest that class I and class II MHC-restricted CTL mediate target cell destruction by an essentially similar direct mechanism

  20. Remnant cationic dendrimers block RNA migration in electrophoresis after monophasic lysis.

    Science.gov (United States)

    Kuo, Jung-Hua Steven; Lin, Yi-Lin

    2007-05-01

    Cationic dendrimers such as poly(amidoamine) (PAMAM) and poly(propyleneimine) (PPI) have attractive characteristics for the delivery of nucleic acid and various biomedical applications. Most studies have focused on cationic dendrimer-based intracellular delivery, and very few studies have focused on the non-specific interaction of remnant cationic dendrimers with total RNA after isolation directly from cells in vitro. We examined RNA isolation using the common method of monophasic lysis from human macrophage-like cells (U937) and mouse fibroblast cells (NIH/3T3) that had been exposed to dendrimers and DNA/dendrimer complexes using gel electrophoresis. We found that PAMAM and PPI dendrimers strongly altered the mobility of RNA in the gels. In addition, the extent of dendrimer-induced alteration in RNA mobility was directly dendrimer-generation-dependent: the alteration was greater with higher-generation dendrimers. We also found that DNA/dendrimer complexes at higher dendrimer to DNA ratios interacted with RNA after isolation while gene expression was maintained. The interactions between RNA and remnant dendrimers after isolation were caused by electrostatic bindings, and we recovered total RNA using high ionic strength solvents (2M NaCl solution) to disrupt the electrostatic forces binding dendrimers to RNA. Because RNA isolation is routinely used for biological applications, such dendrimer-induced alteration in RNA mobility should be accounted for in the further processing of RNA-related applications.

  1. Integrated Multifunctional Electrochemistry Microchip for Highly Efficient Capture, Release, Lysis, and Analysis of Circulating Tumor Cells.

    Science.gov (United States)

    Yan, Shuangqian; Chen, Peng; Zeng, Xuemei; Zhang, Xian; Li, Yiwei; Xia, Yun; Wang, Jie; Dai, Xiaofang; Feng, Xiaojun; Du, Wei; Liu, Bi-Feng

    2017-11-21

    The circulating tumor cells (CTCs) in the blood allow the noninvasive analysis of metastatic mechanisms, cancer diagnosis, prognosis, disease monitoring, and precise therapy through "liquid biopsies". However, there is no integrated and robust multifunctional microchip, which not only could highly efficient capture CTCs, but also fast release and lyse cells on one single chip without using other biochemical agents for downstream biomedical analysis. In this work, we integrated the three functions in one electrochemical microchip (echip) by intentionally designing a cactus-like, topologically structured conductive array consisted of a PDMS micropillar-array core and an electroconductive gold coating layer with hierarchical structure. The echip presented a capture efficiency of 85-100% for different cell lines in both buffer solution and whole blood. Moreover, the validity of the echip was further evaluated by using non-small-cell lung cancer patient samples. The electrochemical released cells or lysed-cell solutions could be obtained within 10 min and have been successfully used for mutant detection by DNA sequencing or RT-PCR. The fast release at a relative low voltage (-1.2 V) was originating from an electrochemical cleavage of the Au-S bonds that immobilized antibody on the chip. The electrochemical lysis took place at a high voltage (20 V) with an admirable performance. Thus, the highly integrated multifunctional echip was well demonstrated and promised a significant application in the clinical field.

  2. Plasma clot lysis time and its association with cardiovascular risk factors in black Africans.

    Science.gov (United States)

    de Lange, Zelda; Pieters, Marlien; Jerling, Johann C; Kruger, Annamarie; Rijken, Dingeman C

    2012-01-01

    Studies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid urbanisation with increased CVD prevalence. We investigated associations between known CVD risk factors and CLT in black Africans and whether CLTs differ between rural and urban participants in light of differences in CVD risk.Data from 1000 rural and 1000 urban apparently healthy black South Africans (35-60 years) were cross-sectionally analysed.Increased PAI-1(act), BMI, HbA1c, triglycerides, the metabolic syndrome, fibrinogen concentration, CRP, female sex and positive HIV status were associated with increased CLTs, while habitual alcohol consumption associated with decreased CLT. No differences in CLT were found between age and smoking categories, contraceptive use or hyper- and normotensive participants. Urban women had longer CLT than rural women while no differences were observed for men.CLT was associated with many known CVD risk factors in black Africans. Differences were however observed, compared to data from populations of European descent available in the literature, suggesting possible ethnic differences. The effect of urbanisation on CLT is influenced by traditional CVD risk factors and their prevalence in urban and rural communities.

  3. Exhaustive extraction of peptides by electromembrane extraction

    DEFF Research Database (Denmark)

    Huang, Chuixiu; Gjelstad, Astrid; Pedersen-Bjergaard, Stig

    2015-01-01

    trifluoroacetate, and leu-enkephalin were extracted from 600 μL of 25 mM phosphate buffer (pH 3.5), through a supported liquid membrane (SLM) containing di-(2-ethylhexyl)-phosphate (DEHP) dissolved in an organic solvent, and into 600 μL of an acidified aqueous acceptor solution using a thin flat membrane-based EME......This fundamental work illustrates for the first time the possibility of exhaustive extraction of peptides using electromembrane extraction (EME) under low system-current conditions (... device. Mass transfer of peptides across the SLM was enhanced by complex formation with the negatively charged DEHP. The composition of the SLM and the extraction voltage were important factors influencing recoveries and current with the EME system. 1-nonanol diluted with 2-decanone (1:1 v/v) containing...

  4. Study of a novel cell lysis method with titanium dioxide for Lab-on-a-Chip devices.

    Science.gov (United States)

    Wan, Weijie; Yeow, John T W

    2011-06-01

    In this paper, a novel method is proposed and demonstrated to be able to lyse gram-negative (E. coli) bacteria cells for Lab-on-a-Chip applications. The proposed method incorporates using titanium dioxide particles as photocatalysts and a miniaturized UV LED array as an excitation light source to perform cell lysis on microchips. The experimental result demonstrates the feasibility of the proposed prototype device. The working device suggests an inexpensive, easy to be fabricated and effective way for microchip cell lysis. The miniaturized UV LED array and the microchip with a reaction chamber can be easily integrated with other functional components to form a customized whole Lab-on-a-Chip system.

  5. Estimates of bacterioplankton and Synechococcus spp. mortality from nanoflagellate grazing and viral lysis in the subtropical Danshui River estuary

    Science.gov (United States)

    Tsai, An-Yi; Gong, Gwo-Ching; Huang, Yu Wen; Chao, Chien Fu

    2015-02-01

    To better understand picoplankton dynamics in the surface waters of upriver the Danshui River and its estuary, we assessed nanoflagellate-induced and virus-induced mortality of bacteria and Synechococcus spp. during different seasons (October, 2012 and January, April and July, 2013) using a modified dilution technique. Bacteria and viruses were significantly higher in abundance upriver than at the estuary. The distribution of Synechococcus spp. did not follow this spatial pattern. Abundance of Synechococcus spp. was relatively low during the whole sampling period in the upriver region. Furthermore, bacterial mortality resulting from nanoflagellate grazing were generally higher than those resulting from viral lysis in the upriver region, while Synechococcus spp. losses appeared to be mainly due to viral lysis upriver and in the estuary. Our dilution experiments suggested that nanoflagellates largely depend on bacteria as an important energy source there.

  6. Extraction and preconcentration of tylosin from milk samples through functionalized TiO₂ nanoparticles reinforced with a hollow fiber membrane as a novel solid/liquid-phase microextraction technique.

    Science.gov (United States)

    Sehati, Negar; Dalali, Nasser; Soltanpour, Shahla; Dorraji, Mir Saeed Seyed

    2014-08-01

    The aim of this study was to introduce a novel, simple, and highly sensitive preparation method for determination of tylosin in different milk samples. In the so-called functionalized TiO2 hollow fiber solid/liquid-phase microextraction method, the acceptor phase is functionalized TiO2 nanoparticles that are dispersed in the organic solvent and held in the pores and lumen of a porous polypropylene hollow fiber membrane. An effective functionalization of TiO2 nanoparticles has been done in the presence of aqueous H2 O2 and a mild acidic ambient under UV irradiation. This novel extraction method showed excellent extraction efficiency and a high enrichment factor (540.2) in comparison with conventional hollow fiber liquid-phase microextraction. All the experiments were monitored at λmax = 284 nm using a simple double beam UV-visible spectrophotometer. A Taguchi orthogonal array experimental design with an OA16 (4(5) ) matrix was employed to optimize the factors affecting the efficiency of hollow fiber solid/liquid-phase microextraction such as pH, stirring rate, salt addition, extraction time, and the volume of donor phase. This developed method was successfully applied for the separation and determination of tylosin in milk samples with a linear concentration range of 0.51-7000 μg/L (r(2) = 0.991) and 0.21 μg/L as the limit of detection. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Determining Human Clot Lysis Time (in vitro with Plasminogen/Plasmin from Four Species (Human, Bovine, Goat, and Swine

    Directory of Open Access Journals (Sweden)

    Omaira Cañas Bermúdez

    2015-05-01

    Full Text Available Cardiovascular disease is the leading cause of death worldwide, including failures in the plasminogen/plasmin system which is an important factor in poor lysis of blood clots. This article studies the fibrinolytic system in four species of mammals, and it identifies human plasminogen with highest thrombolysis efficiency. It examines plasminogen from four species (human, bovine, goat, and swine and identifies the most efficient one in human clot lysis in vitro. All plasminogens were identically purified by affinity chromatography. Human fibrinogen was purified by fractionation with ethanol. The purification of both plasminogen and fibrinogen was characterized by one-dimensional SDS-PAGE (10%. Human clot formation in vitro and its dissolution by plasminogen/plasmin consisted of determining lysis time from clot formation to its dilution. Purification of proteins showed greater than 95% purity, human plasminogen showed greater ability to lyse clot than animal plasminogen. The article concludes that human plasminogen/plasmin has the greatest catalysis and efficiency, as it dissolves human clot up to three times faster than that of irrational species.

  8. A super-family of transcriptional activators regulates bacteriophage packaging and lysis in Gram-positive bacteria

    Science.gov (United States)

    Quiles-Puchalt, Nuria; Tormo-Más, María Ángeles; Campoy, Susana; Toledo-Arana, Alejandro; Monedero, Vicente; Lasa, Íñigo; Novick, Richard P.; Christie, Gail E.; Penadés, José R.

    2013-01-01

    The propagation of bacteriophages and other mobile genetic elements requires exploitation of the phage mechanisms involved in virion assembly and DNA packaging. Here, we identified and characterized four different families of phage-encoded proteins that function as activators required for transcription of the late operons (morphogenetic and lysis genes) in a large group of phages infecting Gram-positive bacteria. These regulators constitute a super-family of proteins, here named late transcriptional regulators (Ltr), which share common structural, biochemical and functional characteristics and are unique to this group of phages. They are all small basic proteins, encoded by genes present at the end of the early gene cluster in their respective phage genomes and expressed under cI repressor control. To control expression of the late operon, the Ltr proteins bind to a DNA repeat region situated upstream of the terS gene, activating its transcription. This involves the C-terminal part of the Ltr proteins, which control specificity for the DNA repeat region. Finally, we show that the Ltr proteins are the only phage-encoded proteins required for the activation of the packaging and lysis modules. In summary, we provide evidence that phage packaging and lysis is a conserved mechanism in Siphoviridae infecting a wide variety of Gram-positive bacteria. PMID:23771138

  9. Membrane paradigm

    International Nuclear Information System (INIS)

    Price, R.H.; Thorne, K.S.

    1986-01-01

    The membrane paradigm is a modified frozen star approach to modeling black holes, with particles and fields assuming a complex, static, boundary-layer type structure (membrane) near the event horizon. The membrane has no effects on the present or future evolution of particles and fields above itself. The mathematical representation is a combination of a formalism containing terms for the shear and bulk viscosity, surface pressure, momentum, temperature, entropy, etc., of the horizon and the 3+1 formalism. The latter model considers a family of three-dimensional spacelike hypersurfaces in one-dimensional time. The membrane model considers a magnetic field threading the hole and undergoing torque from the hole rotation. The field is cleaned by the horizon and distributed over the horizon so that ohmic dissipation is minimized. The membrane paradigm is invalid inside the horizon, but is useful for theoretically probing the properties of slowly evolving black holes

  10. Membrane processes

    Science.gov (United States)

    Staszak, Katarzyna

    2017-11-01

    The membrane processes have played important role in the industrial separation process. These technologies can be found in all industrial areas such as food, beverages, metallurgy, pulp and paper, textile, pharmaceutical, automotive, biotechnology and chemical industry, as well as in water treatment for domestic and industrial application. Although these processes are known since twentieth century, there are still many studies that focus on the testing of new membranes' materials and determining of conditions for optimal selectivity, i. e. the optimum transmembrane pressure (TMP) or permeate flux to minimize fouling. Moreover the researchers proposed some calculation methods to predict the membrane processes properties. In this article, the laboratory scale experiments of membrane separation techniques, as well their validation by calculation methods are presented. Because membrane is the "heart" of the process, experimental and computational methods for its characterization are also described.

  11. Two mini-preparation protocols to DNA extraction from plants with ...

    African Journals Online (AJOL)

    AJB SERVER

    2006-10-16

    Oct 16, 2006 ... The combination of CTAB lysis procedure-solvent extraction and DNA column purification (DNeasy plant mini kit modification) ... 20% SDS. 3 M potassium acetate. TE buffer, pH 8.0. Sterile and deionized water. 3 M sodium acetate, pH 5.2. Cold isopropanol. Chloroform:octhanol (24:1). Protocol: To 500 mg ...

  12. In vitro thrombolytic potential of root extracts of four medicinal plants available in Bangladesh.

    Science.gov (United States)

    Hussain, Fahad; Islam, Ariful; Bulbul, Latifa; Moghal, Mizanur Rahman; Hossain, Mohammad Salim

    2014-01-01

    Thrombus formation inside the blood vessels obstructs blood flow through the circulatory system leading hypertension, stroke to the heart, anoxia, and so on. Thrombolytic drugs are widely used for the management of cerebral venous sinus thrombosis patients, but they have certain limitations. Medicinal plants and their components possessing antithrombotic activity have been reported before. However, plants that could be used for thrombolysis has not been reported so far. This study's aim was to evaluate the thrombolytic potential of selected plants' root extracts. Plants were collected, dried, powdered and extracted by methanol and then fractionated by n-hexane for getting the sample root extracts. Venous blood samples were drawn from 10 healthy volunteers for the purposes of investigation. An in vitro thrombolytic model was used to check the clot lysis potential of four n-hexane soluble roots extracts viz., Acacia nilotica, Justicia adhatoda, Azadirachta indica, and Lagerstroemia speciosa along with streptokinase as a positive control and saline water as a negative control. Dunnett t-test analysis was performed using SPSS is a statistical analysis program developed by IBM Corporation, USA. on Windows. Using an in vitro thrombolytic model, A. nilotica, L. speciosa, A. indica, and J. adhatoda at 5 mg extract/ml NaCl solution concentration showed 15.1%, 15.49%, 21.26%, and 19.63% clot lysis activity respectively. The reference streptokinase showed 47.21%, and 24.73% clot lysis for 30,000 IU and 15,000 IU concentrations, respectively whereas 0.9% normal saline showed 5.35% clot lysis. The selected extracts of the plant roots possess marked thrombolytic properties that could lyse blood clots in vitro; however, in vivo clot dissolving properties and active components responsible for clot lysis are yet to be discovered.

  13. Development and characterization of the α3β4α5 nicotinic receptor cellular membrane affinity chromatography column and its application for on line screening of plant extracts.

    Science.gov (United States)

    Ciesla, L; Okine, M; Rosenberg, A; Dossou, K S S; Toll, L; Wainer, I W; Moaddel, R

    2016-01-29

    The α3β4α5 nAChR has been recently shown to be a useful target for smoking cessation pharmacotherapies. Herein, we report on the development and characterization of the α3β4α5 nicotinic receptor column by frontal displacement chromatography. The binding affinity of the nicotine and minor alkaloids found in tobacco smoke condensates were determined for both the α3β4 and α3β4α5 nicotinic receptors. It was demonstrated that while no subtype selectivity was observed for nicotine and nornicotine, anabasine was selective for the α3β4α5 nicotinic receptor. The non-competitive inhibitor binding site was also studied and it was demonstrated while mecamylamine was not selective between subtypes, buproprion showed subtype selectivity for the α3β4 nicotinic receptor. The application of this methodology to complex mixtures was then carried out by screening aqueous-alcoholic solutions of targeted plant extracts, including Lycopodium clavatum L. (Lycopodiaceae) and Trigonella foenum graecum L. (Fabaceae) against both the α3β4 and α3β4α5 nAChRs. Published by Elsevier B.V.

  14. Viral lysis of photosynthesizing microbes as a mechanism for calcium carbonate nucleation in seawater

    Science.gov (United States)

    Lisle, John T.; Robbins, Lisa L.

    2016-01-01

    Removal of carbon through the precipitation and burial of calcium carbonate in marine sediments constitutes over 70% of the total carbon on Earth and is partitioned between coastal and pelagic zones. The precipitation of authigenic calcium carbonate in seawater, however, has been hotly debated because despite being in a supersaturated state, there is an absence of persistent precipitation. One of the explanations for this paradox is the geochemical conditions in seawater cannot overcome the activation energy barrier for the first step in any precipitation reaction; nucleation. Here we show that virally induced rupturing of photosynthetic cyanobacterial cells releases cytoplasmic-associated bicarbonate at concentrations ~23-fold greater than in the surrounding seawater, thereby shifting the carbonate chemistry toward the homogenous nucleation of one or more of the calcium carbonate polymorphs. Using geochemical reaction energetics, we show the saturation states (Ω) in typical seawater for calcite (Ω = 4.3), aragonite (Ω = 3.1), and vaterite (Ω = 1.2) are significantly elevated following the release and diffusion of the cytoplasmic bicarbonate (Ωcalcite = 95.7; Ωaragonite = 68.5; Ωvaterite = 25.9). These increases in Ω significantly reduce the activation energy for nuclei formation thresholds for all three polymorphs, but only vaterite nucleation is energetically favored. In the post-lysis seawater, vaterite's nuclei formation activation energy is significantly reduced from 1.85 × 10−17 J to 3.85 × 10−20 J, which increases the nuclei formation rate from highly improbable (seawater describes a mechanism through which the initial step in the production of carbonate sediments may proceed. It also presents an additional role of photosynthesizing microbes and their viruses in marine carbon cycles and reveals these microorganisms are a collective repository for concentrated and reactive dissolved inorganic carbon (DIC) that is currently not accounted for

  15. Comparison of the lysis centrifugation method with the conventional blood culture method in cases of sepsis in a tertiary care hospital.

    Science.gov (United States)

    Parikh, Harshal R; De, Anuradha S; Baveja, Sujata M

    2012-07-01

    Physicians and microbiologists have long recognized that the presence of living microorganisms in the blood of a patient carries with it considerable morbidity and mortality. Hence, blood cultures have become critically important and frequently performed test in clinical microbiology laboratories for diagnosis of sepsis. To compare the conventional blood culture method with the lysis centrifugation method in cases of sepsis. Two hundred nonduplicate blood cultures from cases of sepsis were analyzed using two blood culture methods concurrently for recovery of bacteria from patients diagnosed clinically with sepsis - the conventional blood culture method using trypticase soy broth and the lysis centrifugation method using saponin by centrifuging at 3000 g for 30 minutes. Overall bacteria recovered from 200 blood cultures were 17.5%. The conventional blood culture method had a higher yield of organisms, especially Gram positive cocci. The lysis centrifugation method was comparable with the former method with respect to Gram negative bacilli. The sensitivity of lysis centrifugation method in comparison to conventional blood culture method was 49.75% in this study, specificity was 98.21% and diagnostic accuracy was 89.5%. In almost every instance, the time required for detection of the growth was earlier by lysis centrifugation method, which was statistically significant. Contamination by lysis centrifugation was minimal, while that by conventional method was high. Time to growth by the lysis centrifugation method was highly significant (P value 0.000) as compared to time to growth by the conventional blood culture method. For the diagnosis of sepsis, combination of the lysis centrifugation method and the conventional blood culture method with trypticase soy broth or biphasic media is advocable, in order to achieve faster recovery and a better yield of microorganisms.

  16. Virus-specific HLA-restricted lysis of herpes simplex virus-infected human monocytes and macrophages mediated by cytotoxic T lymphocytes

    International Nuclear Information System (INIS)

    Torpey, D.J. III.

    1987-01-01

    Freshly-isolated peripheral blood human monocytes and 5 day in vitro cultured macrophages were infected with herpes simplex virus type 1 (HSV-1), labeled with 51 Cr, and used as target cells in a 12-14 hour cell-mediated cytotoxicity assay. Mononuclear leukocytes (MNL) from HSV-1 non-immune individuals, whether unstimulated or stimulated with HSV-1 antigen, did not mediate significant lysis of either target cell. HSV-immune MNL, both freshly-isolated and cultured for 5 days without antigen, demonstrated only low levels of natural killer (NK) cell-mediate lysis. MNL from HSV-immune individuals incubated for 5 days in vitro with HSV-1 antigen mediated significant virus-specific lysis of both target cells. Mean virus-specific lysis of autologous monocytes was 8.5(/+-/2.0)% compared to a three-fold greater virus-specific lysis of autologous macrophages. Greater than 70% of this lytic activity was mediated by Leu-11-negative, T3-positive cytotoxic T lymphocytes (CTL). Allogeneic target cells lacking a common HLA determinant were not significantly lysed while T8-positive CTL mediated infrequent lysis of target cells sharing a common HLA-A and/or HLA-B determinant. T4-positive lymphocytes were demonstrated to be the predominant cell mediating lysis of autologous target cells and allogeneic target cells sharing both HLA-A and/or HLA-B plus HLA-DR determinants with the CTL; the T4-positive cell was the sole CTL mediator of lysis of allogeneic target cells having a common HLA-DR determinant

  17. Aqueous Cinnamon Extract (ACE-c from the bark of Cinnamomum cassia causes apoptosis in human cervical cancer cell line (SiHa through loss of mitochondrial membrane potential

    Directory of Open Access Journals (Sweden)

    Chattopadhyay Samit

    2010-05-01

    Full Text Available Abstract Background Chemoprevention, which includes the use of synthetic or natural agents (alone or in combination to block the development of cancer in human beings, is an extremely promising strategy for cancer prevention. Cinnamon is one of the most widely used herbal medicines with diverse biological activities including anti-tumor activity. In the present study, we have reported the anti-neoplastic activity of cinnamon in cervical cancer cell line, SiHa. Methods The aqueous cinnamon extract (ACE-c was analyzed for its cinnamaldehyde content by HPTLC analysis. The polyphenol content of ACE-c was measured by Folin-Ciocalteau method. Cytotoxicity analysis was performed by MTT assay. We studied the effect of cinnamon on growth kinetics by performing growth curve, colony formation and soft agar assays. The cells treated with ACE-c were analyzed for wound healing assay as well as for matrix metalloproteinase-2 (MMP-2 expression at mRNA and protein level by RT-PCR and zymography, respectively. Her-2 protein expression was analyzed in the control and ACE-c treated samples by immunoblotting as well as confocal microscopy. Apoptosis studies and calcium signaling assays were analyzed by FACS. Loss of mitochondrial membrane potential (Δψm in cinnamon treated cells was studied by JC-1 staining and analyzed by confocal microscopy as well as FACS. Results Cinnamon alters the growth kinetics of SiHa cells in a dose-dependent manner. Cells treated with ACE-c exhibited reduced number of colonies compared to the control cells. The treated cells exhibited reduced migration potential that could be explained due to downregulation of MMP-2 expression. Interestingly, the expression of Her-2 oncoprotein was significantly reduced in the presence of ACE-c. Cinnamon extract induced apoptosis in the cervical cancer cells through increase in intracellular calcium signaling as well as loss of mitochondrial membrane potential. Conclusion Cinnamon could be used as a

  18. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...

  19. Artificial intelligence versus statistical modeling and optimization of continuous bead milling process for bacterial cell lysis

    Directory of Open Access Journals (Sweden)

    Shafiul Haque

    2016-11-01

    Full Text Available AbstractFor a commercially viable recombinant intracellular protein production process, efficient cell lysis and protein release is a major bottleneck. The recovery of recombinant protein, cholesterol oxidase (COD was studied in a continuous bead milling process. A full factorial Response Surface Model (RSM design was employed and compared to Artificial Neural Networks coupled with Genetic Algorithm (ANN-GA. Significant process variables, cell slurry feed rate (A, bead load (B, cell load (C and run time (D, were investigated and optimized for maximizing COD recovery. RSM predicted an optimum of feed rate of 310.73 mL/h, bead loading of 79.9% (v/v, cell loading OD600 nm of 74, and run time of 29.9 min with a recovery of ~3.2 g/L. ANN coupled with GA predicted a maximum COD recovery of ~3.5 g/L at an optimum feed rate (mL/h: 258.08, bead loading (%, v/v: 80%, cell loading (OD600 nm: 73.99, and run time of 32 min. An overall 3.7-fold increase in productivity is obtained when compared to a batch process. Optimization and comparison of statistical vs. artificial intelligence techniques in continuous bead milling process has been attempted for the very first time in our study. We were able to successfully represent the complex non-linear multivariable dependence of enzyme recovery on bead milling parameters. The quadratic second order response functions are not flexible enough to represent such complex non-linear dependence. ANN being a summation function of multiple layers are capable to represent complex non-linear dependence of variables in this case; enzyme recovery as a function of bead milling parameters. Since GA can even optimize discontinuous functions present study cites a perfect example of using machine learning (ANN in combination with evolutionary optimization (GA for representing undefined biological functions which is the case for common industrial processes involving biological moieties.

  20. Killing of Staphylococci by θ-Defensins Involves Membrane Impairment and Activation of Autolytic Enzymes

    Directory of Open Access Journals (Sweden)

    Miriam Wilmes

    2014-11-01

    Full Text Available θ-Defensins are cyclic antimicrobial peptides expressed in leukocytes of Old world monkeys. To get insight into their antibacterial mode of action, we studied the activity of RTDs (rhesus macaque θ-defensins against staphylococci. We found that in contrast to other defensins, RTDs do not interfere with peptidoglycan biosynthesis, but rather induce bacterial lysis in staphylococci by interaction with the bacterial membrane and/or release of cell wall lytic enzymes. Potassium efflux experiments and membrane potential measurements revealed that the membrane impairment by RTDs strongly depends on the energization of the membrane. In addition, RTD treatment caused the release of Atl-derived cell wall lytic enzymes probably by interaction with membrane-bound lipoteichoic acid. Thus, the premature and uncontrolled activity of these enzymes contributes strongly to the overall killing by θ-defensins. Interestingly, a similar mode of action has been described for Pep5, an antimicrobial peptide of bacterial origin.

  1. Comparative analysis of protocols for DNA extraction from soybean caterpillars.

    Science.gov (United States)

    Palma, J; Valmorbida, I; da Costa, I F D; Guedes, J V C

    2016-04-07

    Genomic DNA extraction is crucial for molecular research, including diagnostic and genome characterization of different organisms. The aim of this study was to comparatively analyze protocols of DNA extraction based on cell lysis by sarcosyl, cetyltrimethylammonium bromide, and sodium dodecyl sulfate, and to determine the most efficient method applicable to soybean caterpillars. DNA was extracted from specimens of Chrysodeixis includens and Spodoptera eridania using the aforementioned three methods. DNA quantification was performed using spectrophotometry and high molecular weight DNA ladders. The purity of the extracted DNA was determined by calculating the A260/A280 ratio. Cost and time for each DNA extraction method were estimated and analyzed statistically. The amount of DNA extracted by these three methods was sufficient for PCR amplification. The sarcosyl method yielded DNA of higher purity, because it generated a clearer pellet without viscosity, and yielded high quality amplification products of the COI gene I. The sarcosyl method showed lower cost per extraction and did not differ from the other methods with respect to preparation times. Cell lysis by sarcosyl represents the best method for DNA extraction in terms of yield, quality, and cost effectiveness.

  2. Complete Genomic and Lysis-Cassette Characterization of the Novel Phage, KBNP1315, which Infects Avian Pathogenic Escherichia coli (APEC.

    Directory of Open Access Journals (Sweden)

    Jung Seok Lee

    Full Text Available Avian pathogenic Escherichia coli (APEC is a major pathogen that causes avian colibacillosis and is associated with severe economic losses in the chicken-farming industry. Here, bacteriophage KBNP1315, infecting APEC strain KBP1315, was genomically and functionally characterized. The evolutionary relationships of KBNP1315 were analyzed at the genomic level using gene (protein-sharing networks, the Markov clustering (MCL algorithm, and comparative genomics. Our network analysis showed that KBNP1315 was connected to 30 members of the Autographivirinae subfamily, which comprises the SP6-, T7-, P60-, phiKMV-, GAP227- and KP34-related groups. Network decomposition suggested that KBNP1315 belongs to the SP6-like phages, but our comparison of putative encoded proteins revealed that key proteins of KBNP1315, including the tail spike protein and endolysin, had relative low levels of amino acid sequence similarity with other members of the SP6-like phages. Thus KBNP1315 may only be distantly related to the SP6-like phages, and (based on the difference in endolysin its lysis mechanism may differ from theirs. To characterize the lytic functions of the holin and endolysin proteins from KBNP1315, we expressed these proteins individually or simultaneously in E. coli BL21 (DE3 competent cell. Interestingly, the expressed endolysin was secreted into the periplasm and caused a high degree of host cell lysis that was dose-dependently delayed/blocked by NaN3-mediated inhibition of the SecA pathway. The expressed holin triggered only a moderate inhibition of cell growth, whereas coexpression of holin and endolysin enhanced the lytic effect of endolysin. Together, these results revealed that KBNP1315 appears to use a pin-holin/signal-arrest-release (SAR endolysin pathway to trigger host cell lysis.

  3. The lysis cassette of bacteriophage ϕKMV encodes a signal-arrest-release endolysin and a pinholin

    OpenAIRE

    Briers, Yves; Peeters, Liesbet M; Volckaert, Guido; Lavigne, Rob

    2011-01-01

    The lysis cassette of Pseudomonas aeruginosa phage ϕKMV encodes a holin, endolysin, Rz and Rz1 in the canonical order. It has a tight organization with a high degree of overlapping genes and is highly conserved (between 96 and 100% identity at the protein level) among several other members of the “phiKMV-like viruses.” The endolysin KMV45 exhibits characteristics as expected for a signal-arrest-release (SAR) endolysin, whereas the holin KMV44 is a typical pinholin. KMV45 is initially secreted...

  4. The SV40 late protein VP4 is a viroporin that forms pores to disrupt membranes for viral release.

    Directory of Open Access Journals (Sweden)

    Smita Raghava

    2011-06-01

    Full Text Available Nonenveloped viruses are generally released by the timely lysis of the host cell by a poorly understood process. For the nonenveloped virus SV40, virions assemble in the nucleus and then must be released from the host cell without being encapsulated by cellular membranes. This process appears to involve the well-controlled insertion of viral proteins into host cellular membranes rendering them permeable to large molecules. VP4 is a newly identified SV40 gene product that is expressed at late times during the viral life cycle that corresponds to the time of cell lysis. To investigate the role of this late expressed protein in viral release, water-soluble VP4 was expressed and purified as a GST fusion protein from bacteria. Purified VP4 was found to efficiently bind biological membranes and support their disruption. VP4 perforated membranes by directly interacting with the membrane bilayer as demonstrated by flotation assays and the release of fluorescent markers encapsulated into large unilamellar vesicles or liposomes. The central hydrophobic domain of VP4 was essential for membrane binding and disruption. VP4 displayed a preference for membranes comprised of lipids that replicated the composition of the plasma membranes over that of nuclear membranes. Phosphatidylethanolamine, a lipid found at high levels in bacterial membranes, was inhibitory against the membrane perforation activity of VP4. The disruption of membranes by VP4 involved the formation of pores of ∼3 nm inner diameter in mammalian cells including permissive SV40 host cells. Altogether, these results support a central role of VP4 acting as a viroporin in the perforation of cellular membranes to trigger SV40 viral release.

  5. Critical assessment of extracellular polymeric substances extraction methods from mixed culture biomass

    DEFF Research Database (Denmark)

    Pellicer i Nàcher, Carles; Domingo Felez, Carlos; Mutlu, Ayten Gizem

    2013-01-01

    Extracellular polymeric substances (EPS) have a presumed determinant role in the structure, architecture, strength, filterability, and settling behaviour of microbial solids in biological wastewater treatment processes. Consequently, numerous EPS extraction protocols have recently been published....... This study presents a rigorous and critical assessment of existing physical and chemical EPS extraction methods applied to mixed-culture biomass samples (nitrifying, nitritation-anammox, and activated sludge biomass). A novel fluorescence-based method was developed and calibrated to quantify the lysis...

  6. Strategy for the extraction of yeast DNA from artisan agave must for quantitative PCR analysis.

    Science.gov (United States)

    Kirchmayr, Manuel Reinhart; Segura-Garcia, Luis Eduardo; Flores-Berrios, Ericka Patricia; Gschaedler, Anne

    2011-11-01

    An efficient method for the direct extraction of yeast genomic DNA from agave must was developed. The optimized protocol, which was based on silica-adsorption of DNA on microcolumns, included an enzymatic cell wall degradation step followed by prolonged lysis with hot detergent. The resulting extracts were suitable templates for subsequent qPCR assays that quantified mixed yeast populations in artisan Mexican mezcal fermentations. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Selection of an Appropriate Protein Extraction Method to Study the Phosphoproteome of Maize Photosynthetic Tissue.

    Directory of Open Access Journals (Sweden)

    Inês M Luís

    Full Text Available Often plant tissues are recalcitrant and, due to that, methods relying on protein precipitation, such as TCA/acetone precipitation and phenol extraction, are usually the methods of choice for protein extraction in plant proteomic studies. However, the addition of precipitation steps to protein extraction methods may negatively impact protein recovery, due to problems associated with protein re-solubilization. Moreover, we show that when working with non-recalcitrant plant tissues, such as young maize leaves, protein extraction methods with precipitation steps compromise the maintenance of some labile post-translational modifications (PTMs, such as phosphorylation. Therefore, a critical issue when studying PTMs in plant proteins is to ensure that the protein extraction method is the most appropriate, both at qualitative and quantitative levels. In this work, we compared five methods for protein extraction of the C4-photosynthesis related proteins, in the tip of fully expanded third-leaves. These included: TCA/Acetone Precipitation; Phenol Extraction; TCA/Acetone Precipitation followed by Phenol Extraction; direct extraction in Lysis Buffer (a urea-based buffer; and direct extraction in Lysis Buffer followed by Cleanup with a commercial kit. Protein extraction in Lysis Buffer performed better in comparison to the other methods. It gave one of the highest protein yields, good coverage of the extracted proteome and phosphoproteome, high reproducibility, and little protein degradation. This was also the easiest and fastest method, warranting minimal sample handling. We also show that this method is adequate for the successful extraction of key enzymes of the C4-photosynthetic metabolism, such as PEPC, PPDK, PEPCK, and NADP-ME. This was confirmed by MALDI-TOF/TOF MS analysis of excised spots of 2DE analyses of the extracted protein pools. Staining for phosphorylated proteins in 2DE revealed the presence of several phosphorylated isoforms of PEPC, PPDK

  8. Expression of a Peptidoglycan Hydrolase from Lytic Bacteriophages Atu_ph02 and Atu_ph03 Triggers Lysis of Agrobacterium tumefaciens.

    Science.gov (United States)

    Attai, Hedieh; Rimbey, Jeanette; Smith, George P; Brown, Pamela J B

    2017-12-01

    To provide food security, innovative approaches to preventing plant disease are currently being explored. Here, we demonstrate that lytic bacteriophages and phage lysis proteins are effective at triggering lysis of the phytopathogen Agrobacterium tumefaciens Phages Atu_ph02 and Atu_ph03 were isolated from wastewater and induced lysis of C58-derived strains of A. tumefaciens The coinoculation of A. tumefaciens with phages on potato discs limited tumor formation. The genomes of Atu_ph02 and Atu_ph03 are nearly identical and are ∼42% identical to those of T7 supercluster phages. In silico attempts to find a canonical lysis cassette were unsuccessful; however, we found a putative p hage p eptidoglycan h ydrolase (PPH), which contains a C-terminal transmembrane domain. Remarkably, the endogenous expression of pph in the absence of additional phage genes causes a block in cell division and subsequent lysis of A. tumefaciens cells. When the presumed active site of the N -acetylmuramidase domain carries an inactivating mutation, PPH expression causes extensive cell branching due to a block in cell division but does not trigger rapid cell lysis. In contrast, the mutation of positively charged residues at the extreme C terminus of PPH causes more rapid cell lysis. Together, these results suggest that PPH causes a block in cell division and triggers cell lysis through two distinct activities. Finally, the potent killing activity of this single lysis protein can be modulated, suggesting that it could be engineered to be an effective enzybiotic. IMPORTANCE The characterization of bacteriophages such as Atu_ph02 and Atu_ph03, which infect plant pathogens such as Agrobacterium tumefaciens , may be the basis of new biocontrol strategies. First, cocktails of diverse bacteriophages could be used as a preventative measure to limit plant diseases caused by bacteria; a bacterial pathogen is unlikely to simultaneously develop resistances to multiple bacteriophage species. The

  9. Stability of supported liquid membranes

    NARCIS (Netherlands)

    Neplenbroek, Antonius Maria

    1989-01-01

    This thesis deals with the stability of supported liquid membranes (SLMs). The use of SLMs, in which an extraction liquid containing a carrier is immobilized in the pores of a microporous support, has recently been introduced as a promising new separation technique. Some advantages ascribed to this

  10. Comparative antioxidant capacity, membrane stabilization ...

    African Journals Online (AJOL)

    Comparative antioxidant capacity, membrane stabilization, polyphenol composition and cytotoxicity of the leaf and stem of Cissus multistriata. ... standard anti-inflammatory drug (Indomethacin) used. The extracts are less toxic to the cell (Arthenia salina) with their LC/EC50 higher than that of standard potassium dichromate ...

  11. Comparative antioxidant capacity, membrane stabilization ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-09-03

    Sep 3, 2008 ... In this present study, a comparative evaluation of the antioxidant capacities, phenol and polyphenol composition, membrane stabilization, and cytotoxicity to brine shrimps (Arthemia salina) of the leaf and stem extracts of Cissus multistriata were carried out. 2,2- Diphenyl-1-picryl hydrazyl (DPPH) radical.

  12. Interaction of the antimicrobial peptide polymyxin B1 with both membranes of E. coli: a molecular dynamics study.

    Directory of Open Access Journals (Sweden)

    Nils A Berglund

    2015-04-01

    Full Text Available Antimicrobial peptides are small, cationic proteins that can induce lysis of bacterial cells through interaction with their membranes. Different mechanisms for cell lysis have been proposed, but these models tend to neglect the role of the chemical composition of the membrane, which differs between bacterial species and can be heterogeneous even within a single cell. Moreover, the cell envelope of Gram-negative bacteria such as E. coli contains two membranes with differing compositions. To this end, we report the first molecular dynamics simulation study of the interaction of the antimicrobial peptide, polymyxin B1 with complex models of both the inner and outer membranes of E. coli. The results of >16 microseconds of simulation predict that polymyxin B1 is likely to interact with the membranes via distinct mechanisms. The lipopeptides aggregate in the lipopolysaccharide headgroup region of the outer membrane with limited tendency for insertion within the lipid A tails. In contrast, the lipopeptides readily insert into the inner membrane core, and the concomitant increased hydration may be responsible for bilayer destabilization and antimicrobial function. Given the urgent need to develop novel, potent antibiotics, the results presented here reveal key mechanistic details that may be exploited for future rational drug development.

  13. High Flux Metallic Membranes for Hydrogen Recovery and Membrane Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Buxbaum, Robert

    2010-06-30

    We made and tested over 250 new alloys for use as lower cost, higher flux hydrogen extraction membrane materials. Most of these were intermetallic, or contained significant intermetallic content, particularly based on B2 alloy compositions with at least one refractory component; B2 intermetallics resemble BCC alloys, in structure, but the atoms have relatively fixed positions, with one atom at the corners of the cube, the other at the centers. The target materals we were looking for would contain little or no expensive elements, no strongly toxic or radioactive elements, would have high flux to hydrogen, while being fabricable, brazable, and relatively immune to hydrogen embrittlement and corrosion in operation. The best combination of properties of the membrane materials we developed was, in my opinion, a Pd-coated membrane consisting of V -9 atomic % Pd. This material was relatively cheap, had 5 times the flux of Pd under the same pressure differential, was reasonably easy to fabricate and braze, and not bad in terms of embrittlement. Based on all these factors we project, about 1/3 the cost of Pd, on an area basis for a membrane designed to last 20 years, or 1/15 the cost on a flux basis. Alternatives to this membrane replaced significant fractions of the Pd with Ni and or Co. The cost for these membranes was lower, but so was the flux. We produced successful brazed products from the membrane materials, and made them into flat sheets. We tested, unsuccessfully, several means of fabricating thematerials into tubes, and eventually built a membrane reactor using a new, flat-plate design: a disc and doughnut arrangement, a design that seems well- suited to clean hydrogen production from coal. The membranes and reactor were tested successfully at Western Research. A larger equipment company (Chart Industries) produced similar results using a different flat-plate reactor design. Cost projections of the membrane are shown to be attractive.

  14. Membrane permeabilization of colistin toward pan-drug resistant Gram-negative isolates.

    Science.gov (United States)

    Mohamed, Yasmine Fathy; Abou-Shleib, Hamida Moustafa; Khalil, Amal Mohamed; El-Guink, Nadia Mohamed; El-Nakeeb, Moustafa Ahmed

    2016-01-01

    Pan-drug resistant Gram-negative bacteria, being resistant to most available antibiotics, represent a huge threat to the medical community. Colistin is considered the last therapeutic option for patients in hospital settings. Thus, we were concerned in this study to demonstrate the membrane permeabilizing activity of colistin focusing on investigating its efficiency toward those pan-drug resistant isolates which represent a critical situation. We determined the killing dynamics of colistin against pan-drug resistant isolates. The permeability alteration was confirmed by different techniques as: leakage, electron microscopy and construction of an artificial membrane model; liposomes. Moreover, selectivity of colistin against microbial cells was also elucidated. Colistin was proved to be rapid bactericidal against pan-drug resistant isolates. It interacts with the outer bacterial membrane leading to deformation of its outline, pore formation, leakage of internal contents, cell lysis and finally death. Furthermore, variations in membrane composition of eukaryotic and microbial cells provide a key for colistin selectivity toward bacterial cells. Colistin selectively alters membrane permeability of pan-drug resistant isolates which leads to cell lysis. Colistin was proved to be an efficient last line treatment for pan-drug resistant infections which are hard to treat. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

  15. [A comparative study of blood culture conventional method vs. a modified lysis/centrifugation technique for the diagnosis of fungemias].

    Science.gov (United States)

    Santiago, Axel Rodolfo; Hernández, Betsy; Rodríguez, Marina; Romero, Hilda

    2004-12-01

    The purpose of this work was to compare the efficacy of blood culture conventional method vs. a modified lysis/centrifugation technique. Out of 450 blood specimens received in one year, 100 where chosen for this comparative study: 60 from patients with AIDS, 15 from leukemic patients, ten from febrile neutropenic patients, five from patients with respiratory infections, five from diabetics and five from septicemic patients. The specimens were processed, simultaneously, according to the above mentioned methodologies with daily inspections searching for fungal growth in order to obtain the final identification of the causative agent. The number (40) of isolates recovered was the same using both methods, which included; 18 Candida albicans (45%), ten Candida spp. (25%), ten Histoplasma capsulatum (25%), and two Cryptococcus neoformans (5%). When the fungal growth time was compared by both methods, growth was more rapid when using the modified lysis/centrifugation technique than when using the conventional method. Statistical analysis revealed a significant difference (pcentrifugation technique showed to be more efficacious than the conventional one, and therefore the implementation of this methodology is highly recommended for the isolation of fungi from blood.

  16. Studies on cytotoxic and clot lysis activity of probiotically fermented cocktail juice prepared using Camellia sinensis and Punica grantum

    Science.gov (United States)

    Biswas, Ananya; Deori, Meenakshi; Nivetha, A.; Mohansrinivasan, V.

    2017-11-01

    In the current research the effect of probiotic microorganisms viz; Lactococcus lactis and Lactobacillus plantarum on fermentation of Camellia sinensis and Punica grantum was studied. In vitro test were done to analyze the anticancer, antioxidant and atherosclerosis (clot lysis) properties of fermented juice. The juice was fermented for 48 and 96h, during which concentration of phenolic content, total acid content and free radical scavenging activity of the sample was analyzed by DPPH assay (α, α-diphenyl-β-picrylhydrazyl). Dropping of pH was observed after 48 h of fermentation. The clot lysis activity was found to be 80 % in 100μl concentration of fermented cocktail juice. The 96 h fermented sample has shown around 70% inhibition against colon cancer cell lines. Analytical study of HPLC proves the organic acid production such as ascorbic acid in superior amount for 96h of fermented sample, Based on the retention time, the corresponding peaks were detected at 4.919 and 4.831 min.

  17. Robotic membranes

    DEFF Research Database (Denmark)

    Ramsgaard Thomsen, Mette

    2008-01-01

    , Vivisection and Strange Metabolisms, were developed at the Centre for Information Technology and Architecture (CITA) at the Royal Danish Academy of Fine Arts in Copenhagen as a means of engaging intangible digital data with tactile physical material. As robotic membranes, they are a dual examination...

  18. The Recombinant Sea Urchin Immune Effector Protein, rSpTransformer-E1, Binds to Phosphatidic Acid and Deforms Membranes

    Directory of Open Access Journals (Sweden)

    Cheng Man Lun

    2017-05-01

    Full Text Available The purple sea urchin, Strongylocentrotus purpuratus, possesses a sophisticated innate immune system that functions without adaptive capabilities and responds to pathogens effectively by expressing the highly diverse SpTransformer gene family (formerly the Sp185/333 gene family. The swift gene expression response and the sequence diversity of SpTransformer cDNAs suggest that the encoded proteins have immune functions. Individual sea urchins can express up to 260 distinct SpTransformer proteins, and their diversity suggests that different versions may have different functions. Although the deduced proteins are diverse, they share an overall structure of a hydrophobic leader, a glycine-rich N-terminal region, a histidine-rich region, and a C-terminal region. Circular dichroism analysis of a recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1 demonstrates that it is intrinsically disordered and transforms to α helical in the presence of buffer additives and binding targets. Although native SpTrf proteins are associated with the membranes of perinuclear vesicles in the phagocyte class of coelomocytes and are present on the surface of small phagocytes, they have no predicted transmembrane region or conserved site for glycophosphatidylinositol linkage. To determine whether native SpTrf proteins associate with phagocyte membranes through interactions with lipids, when rSpTrf-E1 is incubated with lipid-embedded nylon strips, it binds to phosphatidic acid (PA through both the glycine-rich region and the histidine-rich region. Synthetic liposomes composed of PA and phosphatidylcholine show binding between rSpTrf-E1 and PA by fluorescence resonance energy transfer, which is associated with leakage of luminal contents suggesting changes in lipid organization and perhaps liposome lysis. Interactions with liposomes also change membrane curvature leading to liposome budding, fusion, and invagination, which is associated with PA clustering induced

  19. The Recombinant Sea Urchin Immune Effector Protein, rSpTransformer-E1, Binds to Phosphatidic Acid and Deforms Membranes.

    Science.gov (United States)

    Lun, Cheng Man; Samuel, Robin L; Gillmor, Susan D; Boyd, Anthony; Smith, L Courtney

    2017-01-01

    The purple sea urchin, Strongylocentrotus purpuratus , possesses a sophisticated innate immune system that functions without adaptive capabilities and responds to pathogens effectively by expressing the highly diverse SpTransformer gene family (formerly the Sp185/333 gene family). The swift gene expression response and the sequence diversity of SpTransformer cDNAs suggest that the encoded proteins have immune functions. Individual sea urchins can express up to 260 distinct SpTransformer proteins, and their diversity suggests that different versions may have different functions. Although the deduced proteins are diverse, they share an overall structure of a hydrophobic leader, a glycine-rich N-terminal region, a histidine-rich region, and a C-terminal region. Circular dichroism analysis of a recombinant SpTransformer protein, rSpTransformer-E1 (rSpTrf-E1) demonstrates that it is intrinsically disordered and transforms to α helical in the presence of buffer additives and binding targets. Although native SpTrf proteins are associated with the membranes of perinuclear vesicles in the phagocyte class of coelomocytes and are present on the surface of small phagocytes, they have no predicted transmembrane region or conserved site for glycophosphatidylinositol linkage. To determine whether native SpTrf proteins associate with phagocyte membranes through interactions with lipids, when rSpTrf-E1 is incubated with lipid-embedded nylon strips, it binds to phosphatidic acid (PA) through both the glycine-rich region and the histidine-rich region. Synthetic liposomes composed of PA and phosphatidylcholine show binding between rSpTrf-E1 and PA by fluorescence resonance energy transfer, which is associated with leakage of luminal contents suggesting changes in lipid organization and perhaps liposome lysis. Interactions with liposomes also change membrane curvature leading to liposome budding, fusion, and invagination, which is associated with PA clustering induced by rSpTrf-E1

  20. Nucleic acid protocols: Extraction and optimization

    Directory of Open Access Journals (Sweden)

    Saeed El-Ashram

    2016-12-01

    Full Text Available Yield and quality are fundamental features for any researchers during nucleic acid extraction. Here, we describe a simplified, semi-unified, effective, and toxic material free protocol for extracting DNA and RNA from different prokaryotic and eukaryotic sources exploiting the physical and chemical properties of nucleic acids. Furthermore, this protocol showed that DNA and RNA are under triple protection (i.e. EDTA, SDS and NaCl during lysis step, and this environment is improper for RNase to have DNA liberated of RNA and even for DNase to degrade the DNA. Therefore, the complete removal of RNA under RNase influence is achieved when RNase is added after DNA extraction, which gives optimal quality with any protocols. Similarly, DNA contamination in an isolated RNA is degraded by DNase to obtain high-quality RNA. Our protocol is the protocol of choice in terms of simplicity, recovery time, environmental safety, amount, purity, PCR and RT-PCR applicability.

  1. Salt effects in electromembrane extraction

    DEFF Research Database (Denmark)

    Seip, Knut Fredrik; Jensen, Henrik; Kieu, Thanh Elisabeth

    2014-01-01

    Electromembrane extraction (EME) was performed on samples containing substantial amounts of NaCl to investigate how the presence of salts affected the recovery, repeatability, and membrane current in the extraction system. A group of 17 non-polar basic drugs with various physical chemical...

  2. Daratumumab-mediated lysis of primary multiple myeloma cells is enhanced in combination with the human anti-KIR antibody IPH2102 and lenalidomide

    DEFF Research Database (Denmark)

    Nijhof, I. S.; Lammerts van Bueren, J. J.; van Kessel, B.

    2015-01-01

    killer cell inhibitory receptors with the human monoclonal anti-KIR antibody IPH2102, next to activation of natural killer cells with the immune modulatory drug lenalidomide. In 4-hour antibody-dependent cell-mediated cytotoxicity assays, IPH2102 did not induce lysis of multiple myeloma cell lines......RIIa-131R allele, who bind IgG1 with lower affinity than patients carrying the FcgammaRIIIa-158V allele or the FcgammaRIIa-131H allele. Finally, a further synergistically improved myeloma cell lysis with the daratumumab-IPH2102 combination was observed by adding lenalidomide, which suggests that more...

  3. Increasing Diversity of Biological Membrane Fission Mechanisms.

    Science.gov (United States)

    Renard, Henri-François; Johannes, Ludger; Morsomme, Pierre

    2018-01-04

    Membrane fission is essential to life. It is required for many fundamental cellular processes, as diverse as cyto- and karyokinesis, organelle division, membrane repair, and membrane trafficking and endocytosis. While membrane fission was originally seen as resulting from the action of mechanoenzymes such as dynamin, it is clear that the reality is more complex. In this review, we propose an updated overview of fission mechanisms, and try to extract essential requirements for each. We also present examples of cellular processes that involve these fission mechanisms. Finally, we list pending questions, whether they are specific to a peculiar fission mechanism or more general to the field. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Outer membrane protein antigens of Moraxella bovis.

    Science.gov (United States)

    Ostle, A G; Rosenbusch, R F

    1986-07-01

    Outer membranes were isolated from bovine isolates and type strains of Moraxella bovis, M phenylpyruvica, M lacunata, and M ovis by sodium N lauroyl sarcosinate extraction and differential centrifugation. Analysis of outer membranes from these organisms by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis revealed that all M bovis isolates shared a common polypeptide pattern that was readily distinguishable from other Moraxella spp. Nine major outer membrane protein bands were identified by sodium dodecyl sulfate-polyacrylamide-gel electrophoresis analysis of M bovis. Immunoblotting of protein antigens of M bovis revealed several outer membrane proteins that seemed to be common antigens of all M bovis isolates.

  5. Membrane Stabilizing Activity And Phytochemistry Of Hibiscus rosa ...

    African Journals Online (AJOL)

    The human erythrocyte membrane stabilizing activity of saline extract of Hibiscus rosa-sinensis leaves was investigated as part of efforts at validating its use as anti-arthritic and anti-inflammatory agent. The results of the membrane stabilizing activity of the extract, when compared to two non-steroidal anti-inflammatory drugs ...

  6. Evaluation of antioxidant capacity and membrane stabilizing ...

    African Journals Online (AJOL)

    Comparative analyses of the antioxidant and membrane stabilizing activities of ethanolic extracts of leaf and root of Cyphospenna adenocaulis (Steud) were investigated with a view to further investigate the biological activities of the plant. Both the leaf and root of C. adenocaulis were extracted with 70% ethanol to yield the ...

  7. Evaluation of antioxidant capacity and membrane stabilizing ...

    African Journals Online (AJOL)

    Kemi Akinwunmi

    2015-05-27

    May 27, 2015 ... Comparative analyses of the antioxidant and membrane stabilizing activities of ethanolic extracts of leaf and root of Cyphospenna adenocaulis (Steud) were investigated with a view to further investigate the biological activities of the plant. Both the leaf and root of C. adenocaulis were extracted with 70%.

  8. A molecular model for membrane fusion based on solution studies of an amphiphilic peptide from HIV gp41.

    Science.gov (United States)

    Fujii, G; Horvath, S; Woodward, S; Eiserling, F; Eisenberg, D

    1992-11-01

    The mechanism of protein-mediated membrane fusion and lysis has been investigated by solution-state studies of the effects of peptides on liposomes. A peptide (SI) corresponding to a highly amphiphilic C-terminal segment from the envelope protein (gp41) of the human immunodeficiency virus (HIV) was synthesized and tested for its ability to cause lipid membranes to fuse together (fusion) or to break open (lysis). These effects were compared to those produced by the lytic and fusogenic peptide from bee venom, melittin. Other properties studied included the changes in visible absorbance and mean particle size, and the secondary structure of peptides as judged by CD spectroscopy. Taken together, the observations suggest that protein-mediated membrane fusion is dependent not only on hydrophobic and electrostatic forces but also on the spatial arrangement of the amino acid residues to form an amphiphilic structure that promotes the mixing of the lipids between membranes. A speculative molecular model is proposed for membrane fusion by alpha-helical peptides, and its relationship to the forces involved in protein-membrane interactions is discussed.

  9. Nano-electromembrane extraction

    DEFF Research Database (Denmark)

    Payán, María D Ramos; Li, Bin; Petersen, Nickolaj J.

    2013-01-01

    The present work has for the first time described nano-electromembrane extraction (nano-EME). In nano-EME, five basic drugs substances were extracted as model analytes from 200 μL acidified sample solution, through a supported liquid membrane (SLM) of 2-nitrophenyl octyl ether (NPOE......), and into approximately 8 nL phosphate buffer (pH 2.7) as acceptor phase. The driving force for the extraction was an electrical potential sustained over the SLM. The acceptor phase was located inside a fused silica capillary, and this capillary was also used for the final analysis of the acceptor phase by capillary...... as extraction selectivity. Compared with conventional EME, the acceptor phase volume in nano-EME was down-scaled by a factor of more than 1000. This resulted in a very high enrichment capacity. With loperamide as an example, an enrichment factor exceeding 500 was obtained in only 5 min of extraction...

  10. Staphylococcus aureus α-toxin-dependent induction of host cell death by membrane-derived vesicles.

    Directory of Open Access Journals (Sweden)

    Bernard Thay

    Full Text Available Staphylococcus aureus causes a wide spectrum of infections in humans, ranging from superficial cutaneous infections, infections in the circum-oral region, to life-threatening bacteremia. It was recently demonstrated that Gram-positive organisms such as S. aureus liberate membrane-derived vesicles (MVs, which analogously to outer membrane vesicles (OMVs of Gram-negative bacteria can play a role in delivering virulence factors to host cells. In the present study we have shown that cholesterol-dependent fusion of S. aureus MVs with the plasma membrane represents a route for delivery of a key virulence factor, α-toxin (α-hemolysin; Hla to human cells. Most S. aureus strains produce this 33-kDa pore-forming protein, which can lyse a wide range of human cells, and induce apoptosis in T-lymphocytes. Our results revealed a tight association of biologically active α-toxin with membrane-derived vesicles isolated from S. aureus strain 8325-4. Concomitantly, α-toxin contributed to HeLa cell cytotoxicity of MVs, and was the main vesicle-associated protein responsible for erythrocyte lysis. In contrast, MVs obtained from an isogenic hla mutant were significantly attenuated with regards to both causing lysis of erythrocytes and death of HeLa cells. This is to our knowledge the first recognition of an S. aureus MV-associated factor contributing to host cell cytotoxicity.

  11. Cytoprotective Effects of Pumpkin (Cucurbita Moschata) Fruit Extract against Oxidative Stress and Carbonyl Stress.

    Science.gov (United States)

    Shayesteh, Reyhaneh; Kamalinejad, Mohammad; Adiban, Hasan; Kardan, Azin; Keyhanfar, Fariborz; Eskandari, Mohammad Reza

    2017-10-01

    Background Diabetes mellitus is a chronic endocrine disorder that is associated with significant mortality and morbidity due to microvascular and macrovascular complications. Diabetes complications accompanied with oxidative stress and carbonyl stress in different organs of human body because of the increased generation of free radicals and impaired antioxidant defense systems. In the meantime, reactive oxygen species (ROS) and reactive carbonyl species (RCS) have key mediatory roles in the development and progression of diabetes complications. Therapeutic strategies have recently focused on preventing such diabetes-related abnormalities using different natural and chemical compounds. Pumpkin ( Cucurbita moschata ) is one of the most important vegetables in the world with a broad-range of pharmacological activities such as antihyperglycemic effect. Methods In the present study, the cytoprotective effects of aqueous extract of C. moschata fruit on hepatocyte cytotoxicity induced by cumene hydroperoxide (oxidative stress model) or glyoxal (carbonylation model) were investigated using freshly isolated rat hepatocytes. Results The extract of C. moschata (50 μg/ml) excellently prevented oxidative and carbonyl stress markers, including hepatocyte lysis, ROS production, lipid peroxidation, glutathione depletion, mitochondrial membrane potential collapse, lysosomal damage, and cellular proteolysis. In addition, protein carbonylation was prevented by C. moschata in glyoxal-induced carbonyl stress. Conclusion It can be concluded that C. moschata has cytoprotective effects in oxidative stress and carbonyl stress models and this valuable vegetable can be considered as a suitable herbal product for the prevention of toxic subsequent of oxidative stress and carbonyl stress seen in chronic hyperglycemia. © Georg Thieme Verlag KG Stuttgart · New York.

  12. Detection of fungal DNA in lysis-centrifugation blood culture for the diagnosis of invasive candidiasis in neonatal patients.

    Science.gov (United States)

    Trovato, L; Betta, P; Romeo, M G; Oliveri, S

    2012-03-01

    We report data concerning the detection of fungal DNA directly from lysis-centrifugation blood culture to assess its value in the detection of fungaemia in 86 of the 347 patients admitted to the neonatal intensive-care unit between January 2009 and December 2010. The sensitivity and specificity of the PCR were 87.5% and 98.5%, respectively, with a positive predictive value of 93.3% and a negative predictive value of 97.1%. Detection of fungal DNA directly from blood culture Isolator 1.5 microbial tubes, without prior cultivation, is a promising approach for the rapid detection of Candida spp. in neonates with suspected candidaemia. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.

  13. RASCAL [Radiological Assessment System for Consequence AnaLysis]: A screening model for estimating doses from radiological accidents

    International Nuclear Information System (INIS)

    Sjoreen, A.L.; Athey, G.F.; Sakenas, C.A.; McKenna, T.J.

    1988-01-01

    The Radiological Assessment System for Consequence AnaLysis (RASCAL) is a new MS-DOS-based dose assessment model which has been written for the US Nuclear Regulatory Commission for use during response to radiological emergencies. RASCAL is designed to provide crude estimates of the effects of an accident while the accident is in progress and only limited information is available. It has been designed to be very simple to use and to run quickly. RASCAL is unique in that it estimates the source term based on fundamental plant conditions and does not rely solely on release rate estimation (e.g., Ci/sec of I-131). Therefore, it can estimate consequences of accidents involving unmonitored pathways or projected failures. RASCAL will replace the older model, IRDAM. 6 refs

  14. High-throughput DNA extraction of forensic adhesive tapes.

    Science.gov (United States)

    Forsberg, Christina; Jansson, Linda; Ansell, Ricky; Hedman, Johannes

    2016-09-01

    Tape-lifting has since its introduction in the early 2000's become a well-established sampling method in forensic DNA analysis. Sampling is quick and straightforward while the following DNA extraction is more challenging due to the "stickiness", rigidity and size of the tape. We have developed, validated and implemented a simple and efficient direct lysis DNA extraction protocol for adhesive tapes that requires limited manual labour. The method uses Chelex beads and is applied with SceneSafe FAST tape. This direct lysis protocol provided higher mean DNA yields than PrepFiler Express BTA on Automate Express, although the differences were not significant when using clothes worn in a controlled fashion as reference material (p=0.13 and p=0.34 for T-shirts and button-down shirts, respectively). Through in-house validation we show that the method is fit-for-purpose for application in casework, as it provides high DNA yields and amplifiability, as well as good reproducibility and DNA extract stability. After implementation in casework, the proportion of extracts with DNA concentrations above 0.01ng/μL increased from 71% to 76%. Apart from providing higher DNA yields compared with the previous method, the introduction of the developed direct lysis protocol also reduced the amount of manual labour by half and doubled the potential throughput for tapes at the laboratory. Generally, simplified manual protocols can serve as a cost-effective alternative to sophisticated automation solutions when the aim is to enable high-throughput DNA extraction of complex crime scene samples. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  15. Influence of environmental variation on the bacterioplankton community and its loss to viral lysis in the Curonian Lagoon

    Science.gov (United States)

    Šulčius, Sigitas; Reunamo, Anna; Paškauskas, Ričardas; Leskinen, Piia

    2018-05-01

    Coastal lagoons are continuously exposed to strong environmental gradients that determine the distribution and trophic interactions of microbial communities. Therefore, in this study we assessed whether and how environmental changes influence the bacterial community and its vulnerability to viral infection and lysis along the major environmental gradient in the Curonian Lagoon. We found significant differences in bacterial community profiles, their richness and evenness between the riverine, freshwater southern part and the Baltic Sea water intrusion-influenced northern part of the lagoon, suggesting strong environmental control of the structure of bacterial communities. Viruses were found to be play an important role in bacterial mortality in the Curonian Lagoon, being responsible for the removal of 20-50% of the bacterial standing stock. We observed differences in virioplankton decay rates and virus burst sizes between the northern and southern parts of the lagoon. However, no relationships were found between viral activity and bacterial communities within the lagoon ecosystem. The frequency of infected cells and virus-mediated bacterial mortality (VMBM) remained constant among the sampling sites irrespective of differences in bacteria community assemblages and environmental conditions. The results indicate that factors determining changes in bacterial diversity are different from the factors limiting their vulnerability to viral infection and lysis. This study also suggests that under changing environmental conditions, virus-bacteria interactions are more stable than the interacting viral and bacterial communities themselves. These findings are important for understanding the functioning of the coastal ecosystems under the rapidly changing local (spatial and temporal) and global (e.g. eutrophication, climate change) conditions.

  16. Extraction du complexe (𕔣P 2 W 17 O 61 Fe)7-, par ...

    African Journals Online (AJOL)

    membrane The extraction of a Dawson-type heteropolyanion (∝1P2W17O61Fe) 7- was carried out by liquid surfactant membrane using (SPAN80) as surfactantand (TIBA) as extractant, internal phase used (NH4)2CO3. The extraction efficiency is 90 %. Then in order to regenerate the membrane, the stripping efficiency was ...

  17. The Cell Lysis Activity of the Streptococcus agalactiae Bacteriophage B30 Endolysin Relies on the Cysteine, Histidine-Dependent Amidohydrolase/Peptidase Domain

    Science.gov (United States)

    Donovan, David M.; Foster-Frey, Juli; Dong, Shengli; Rousseau, Geneviève M.; Moineau, Sylvain; Pritchard, David G.

    2006-01-01

    The Streptococcus agalactiae bacteriophage B30 endolysin contains three domains: cysteine, histidine-dependent amidohydrolase/peptidase (CHAP), Acm glycosidase, and the SH3b cell wall binding domain. Truncations and point mutations indicated that the Acm domain requires the SH3b domain for activity, while the CHAP domain is responsible for nearly all the cell lysis activity. PMID:16820517

  18. Rapid Extraction of Genomic DNA from Medically Important Yeasts and Filamentous Fungi by High-Speed Cell Disruption

    OpenAIRE

    Müller, Frank-Michael C.; Werner, Katherine E.; Kasai, Miki; Francesconi, Andrea; Chanock, Stephen J.; Walsh, Thomas J.

    1998-01-01

    Current methods of DNA extraction from different fungal pathogens are often time-consuming and require the use of toxic chemicals. DNA isolation from some fungal organisms is difficult due to cell walls or capsules that are not readily susceptible to lysis. We therefore investigated a new and rapid DNA isolation method using high-speed cell disruption (HSCD) incorporating chaotropic reagents and lysing matrices in comparison to standard phenol-chloroform (PC) extraction protocols for isolatio...

  19. Evaluation and optimization of DNA extraction and purification procedures for soil and sediment samples.

    Science.gov (United States)

    Miller, D N; Bryant, J E; Madsen, E L; Ghiorse, W C

    1999-11-01

    We compared and statistically evaluated the effectiveness of nine DNA extraction procedures by using frozen and dried samples of two silt loam soils and a silt loam wetland sediment with different organic matter contents. The effects of different chemical extractants (sodium dodecyl sulfate [SDS], chloroform, phenol, Chelex 100, and guanadinium isothiocyanate), different physical disruption methods (bead mill homogenization and freeze-thaw lysis), and lysozyme digestion were evaluated based on the yield and molecular size of the recovered DNA. Pairwise comparisons of the nine extraction procedures revealed that bead mill homogenization with SDS combined with either chloroform or phenol optimized both the amount of DNA extracted and the molecular size of the DNA (maximum size, 16 to 20 kb). Neither lysozyme digestion before SDS treatment nor guanidine isothiocyanate treatment nor addition of Chelex 100 resin improved the DNA yields. Bead mill homogenization in a lysis mixture containing chloroform, SDS, NaCl, and phosphate-Tris buffer (pH 8) was found to be the best physical lysis technique when DNA yield and cell lysis efficiency were used as criteria. The bead mill homogenization conditions were also optimized for speed and duration with two different homogenizers. Recovery of high-molecular-weight DNA was greatest when we used lower speeds and shorter times (30 to 120 s). We evaluated four different DNA purification methods (silica-based DNA binding, agarose gel electrophoresis, ammonium acetate precipitation, and Sephadex G-200 gel filtration) for DNA recovery and removal of PCR inhibitors from crude extracts. Sephadex G-200 spin column purification was found to be the best method for removing PCR-inhibiting substances while minimizing DNA loss during purification. Our results indicate that for these types of samples, optimum DNA recovery requires brief, low-speed bead mill homogenization in the presence of a phosphate-buffered SDS-chloroform mixture, followed

  20. STUDI MEMBRAN KITOSAN DARI KULIT LOBSTER BAMBU SEBAGAI MEMBRAN FILTRASI

    Directory of Open Access Journals (Sweden)

    Ni Nyoman Putri Windari

    2016-02-01

    Full Text Available The study of the extraction and characterization of chitosan from skin waste of Bamboo Lobster (Panulirus versicolor has been done. Chitosan is extracted using conventional method, namely the initial process: cleaning and drying (pretreatment, demineralization, deproteination, and deacetylation. The chitosan obtained has been used to prepare chitosan membrane 2% with acetic acid 1% as solvent. The membrane prepared by phase inversion method withprecipitation through solvent evaporation. The prepared membranes were characterized by FTIR spectrophotometer, Nova 1200e by BJH method and filtration method. The results obtained that degree of deacetylation (DD of chitosan is 70.016%. The thickness of the membrane is 0.361 mm. The FTIR spectra show that functional groups obtained are -NH, -CH, C=O, C-O and -CN. From BJH method obtained that the pore radius is 1.69 nm and pore density is 8.95 x 105pores/m3. From the filtration method obtained that at each pressure, 80-85 kPa and 90-100 kPa, the PWF values are 381.232 and 454.545 L/m2.h, respectively.