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Sample records for activated recombinative desorption

  1. Nanocrystalline NdFeB magnet prepared by mechanically activated disproportionation and desorption-recombination in-situ sintering

    International Nuclear Information System (INIS)

    Xiaoya, Liu; Yuping, Li; Lianxi, Hu

    2013-01-01

    The process of mechanically activated disproportionation and desorption-recombination in-situ sintering was proposed to synthesize highly densified nanocrystalline NdFeB magnet, and its validity was demonstrated by experimental investigation with the use of a Nd 16 Fe 76 B 8 (atomic ratio) alloy. Firstly, the as-cast alloy was disproportionated by mechanical milling in hydrogen, with the starting micron-sized Nd 2 Fe 14 B phase decomposed into an intimate mixture of nano-structured NdH 2.7 , Fe 2 B and α-Fe phases. The as-disproportionated alloy powders were compacted by cold pressing and then subjected to desorption-recombination in-situ sintering. The microstructure of both the as-disproportionated and the subsequently sintered samples was characterized by X-ray diffraction and electron transmission microscopy, respectively. The magnetic properties of the sintered samples were measured by using vibrating sample magnetometer. The results showed that, by vacuum sintering, not only was the powder compact consolidated, but also the as-disproportionated microstucture transformed into nanocrystalline Nd 2 Fe 14 B phase via the well-known desorption-recombination reaction, thus giving rise to nanocrystalline NdFeB magnet. In the present study, the optimal sintering parameters were found to be 780 °C×30 min. In this case, the coercivity, the remanence, and maximum energy product of the magnet sample achieved 0.8 T, 635.3 kA/m, and 106.3 kJ/m 3 , respectively. - Highlights: ► Nano-structured disproportionated NdFeB alloy powders by mechanical milling in hydrogen. ► Highly densified green magnet compact by cold pressing of as-disproportionated NdFeB alloy powders. ► Nanocrystalline NdFeB magnets by desorption-recombination in-situ sintering under vacuum. ► Magnetic properties significantly improved by relative density enhancement and nanocrystallization of Nd 2 Fe 14 B phase. ► The effects of sintering parameters on magnetic properties and the underlying

  2. Nanocrystalline NdFeB magnet prepared by mechanically activated disproportionation and desorption-recombination in-situ sintering

    Energy Technology Data Exchange (ETDEWEB)

    Xiaoya, Liu; Yuping, Li [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Lianxi, Hu, E-mail: hulx@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2013-03-15

    The process of mechanically activated disproportionation and desorption-recombination in-situ sintering was proposed to synthesize highly densified nanocrystalline NdFeB magnet, and its validity was demonstrated by experimental investigation with the use of a Nd{sub 16}Fe{sub 76}B{sub 8} (atomic ratio) alloy. Firstly, the as-cast alloy was disproportionated by mechanical milling in hydrogen, with the starting micron-sized Nd{sub 2}Fe{sub 14}B phase decomposed into an intimate mixture of nano-structured NdH{sub 2.7}, Fe{sub 2}B and {alpha}-Fe phases. The as-disproportionated alloy powders were compacted by cold pressing and then subjected to desorption-recombination in-situ sintering. The microstructure of both the as-disproportionated and the subsequently sintered samples was characterized by X-ray diffraction and electron transmission microscopy, respectively. The magnetic properties of the sintered samples were measured by using vibrating sample magnetometer. The results showed that, by vacuum sintering, not only was the powder compact consolidated, but also the as-disproportionated microstucture transformed into nanocrystalline Nd{sub 2}Fe{sub 14}B phase via the well-known desorption-recombination reaction, thus giving rise to nanocrystalline NdFeB magnet. In the present study, the optimal sintering parameters were found to be 780 Degree-Sign C Multiplication-Sign 30 min. In this case, the coercivity, the remanence, and maximum energy product of the magnet sample achieved 0.8 T, 635.3 kA/m, and 106.3 kJ/m{sup 3}, respectively. - Highlights: Black-Right-Pointing-Pointer Nano-structured disproportionated NdFeB alloy powders by mechanical milling in hydrogen. Black-Right-Pointing-Pointer Highly densified green magnet compact by cold pressing of as-disproportionated NdFeB alloy powders. Black-Right-Pointing-Pointer Nanocrystalline NdFeB magnets by desorption-recombination in-situ sintering under vacuum. Black-Right-Pointing-Pointer Magnetic properties significantly

  3. Carbon tetrachloride desorption from activated carbon

    International Nuclear Information System (INIS)

    Jonas, L.A.; Sansone, E.B.

    1981-01-01

    Carbon tetrachloride was desorbed from a granular activated carbon subsequent to its adsorption under various vapor exposure periods. The varied conditions of exposure resulted in a range of partially saturated carbon beds which, when followed by a constant flow rate for desorption, generated different forms of the desorbing concentration versus time curve. A method of analyzing the desorption curves is presented which permits extraction of the various desorbing rates from the different desorption and to relate this to the time required for such regeneration. The Wheeler desorption kinetic equation was used to calculate the pseudo first order desorption rate constant for the carbon. The desorption rate constant was found to increase monotonically with increasing saturation of the bed, permitting the calculation of the maximum desorption rate constant for the carbon at 100% saturation. The Retentivity Index of the carbon, defined as the dimensionless ratio of the adsorption to the desorption rate constant, was found to be 681

  4. Activated recombinant adenovirus proteinases

    Science.gov (United States)

    Anderson, Carl W.; Mangel, Walter F.

    1999-08-10

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

  5. Recombinant snake venom prothrombin activators

    OpenAIRE

    L?vgren, Ann

    2012-01-01

    Three prothrombin activators; ecarin, which was originally isolated from the venom of the saw-scaled viper Echis carinatus, trocarin from the rough-scaled snake Tropidechis carinatus, and oscutarin from the Taipan snake Oxyuranus scutellatus, were expressed in mammalian cells with the purpose to obtain recombinant prothrombin activators that could be used to convert prothrombin to thrombin. We have previously reported that recombinant ecarin can efficiently generate thrombin without the need ...

  6. Recombinant Cyclophilins Lack Nuclease Activity

    OpenAIRE

    Manteca, Angel; Sanchez, Jesus

    2004-01-01

    Several single-domain prokaryotic and eukaryotic cyclophilins have been identified as also being unspecific nucleases with a role in DNA degradation during the lytic processes that accompany bacterial cell death and eukaryotic apoptosis. Evidence is provided here that the supposed nuclease activity of human and bacterial recombinant cyclophilins is due to contamination of the proteins by the host Escherichia coli endonuclease and is not an intrinsic property of these proteins.

  7. Affinity purification of recombinant human plasminogen activator ...

    African Journals Online (AJOL)

    Affinity purification of recombinant human plasminogen activator from ... Screening antibody was performed using rhPA milk in an ELISA-elution assay. ... useful for purifying other tPA mutants or other novel recombinant milkderived proteins.

  8. On factors controlling activity of submonolayer bimetallic catalysts: Nitrogen desorption

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Wei; Vlachos, Dionisios G., E-mail: vlachos@udel.edu [Center for Catalytic Science and Technology, Catalysis Center for Energy Innovation, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716 (United States)

    2014-01-07

    We model N{sub 2} desorption on submonolayer bimetallic surfaces consisting of Co clusters on Pt(111) via first-principles density functional theory-based kinetic Monte Carlo simulations. We find that submonolayer structures are essential to rationalize the high activity of these bimetallics in ammonia decomposition. We show that the N{sub 2} desorption temperature on Co/Pt(111) is about 100 K higher than that on Ni/Pt(111), despite Co/Pt(111) binding N weaker at low N coverages. Co/Pt(111) has substantially different lateral interactions than single metals and Ni/Pt. The lateral interactions are rationalized with the d-band center theory. The activity of bimetallic catalysts is the result of heterogeneity of binding energies and reaction barriers among sites, and the most active site can differ on various bimetallics. Our results are in excellent agreement with experimental data and demonstrate for the first time that the zero-coverage descriptor, used until now, for catalyst activity is inadequate due not only to lacking lateral interactions but importantly to presence of multiple sites and a complex interplay of thermodynamics (binding energies, occupation) and kinetics (association barriers) on those sites.

  9. Molecular requirements for radiation-activated recombination

    International Nuclear Information System (INIS)

    Stevens, Craig W.; Zeng Ming; Stamato, Thomas; Cerniglia, George

    1997-01-01

    Purpose/Objective: The major stumbling block to successful gene therapy today is poor gene transfer. We hypothesized that ionizing radiation might activate cellular recombination, and so improve stable gene transfer. We further hypothesized that known DNA-damage-repair proteins might also be important in radiation-activated recombination. Materials and Methods: The effect of irradiation on stable gene transfer efficiency was determined in human (A549 and 39F) and rodent (NIH/3T3) cell lines. Continuous low dose rate and multiple radiation fractions were also tested. Nuclear extracts were made and the effect of irradiation on inter-plasmid recombination/ligation determined. Multiple DNA damage-repair deficient cell lines were tested for radiation-activated recombination. Results: A significant radiation dose-dependent improvement in stable plasmid transfection (by as much as 1300 fold) is demonstrated in neoplastic and primary cells. An improvement in transient plasmid transfection is also seen, with as much as 85% of cells transiently expressing b-galactosidase (20-50 fold improvement). Stable transfection is only improved for linearized or nicked plasmids. Cells have improved gene transfer for at least 96 hours after irradiation. Both fractionated and continuous low dose rate irradiation are effective at improving stable gene transfer in mammalian cells, thus making relatively high radiation dose delivery clinically feasible. Inter-plasmid recombination is radiation dose dependent in nuclear extract assays, and the type of overhang (3', 5' or blunt end) significantly affects recombination efficiency and the type of product. The most common end-joining activity involves filling-in of the overhang followed by blunt end ligation. Adenovirus is a linear, double stranded DNA virus. We demonstrate that adenoviral infection efficiency is increased by irradiation. The duration of transgene expression is lengthened because the virus integrates with high efficiency (∼10

  10. Co-factor activated recombinant adenovirus proteinases

    Science.gov (United States)

    Anderson, Carl W.; Mangel, Walter F.

    1996-08-06

    This application describes methods and expression constructs for producing activatable recombinant adenovirus proteinases. Purified activatable recombinant adenovirus proteinases and methods of purification are described. Activated adenovirus proteinases and methods for obtaining activated adenovirus proteinases are further included. Isolated peptide cofactors of adenovirus proteinase activity, methods of purifying and identifying said peptide cofactors are also described. Antibodies immunoreactive with adenovirus proteinases, immunospecific antibodies, and methods for preparing them are also described. Other related methods and materials are also described.

  11. Adsorption/Desorption Transition of Recombinant Human Neurotrophin 4: Physicochemical Characterization.

    Science.gov (United States)

    Dąbkowska, Maria; Adamczak, Małgorzata; Barbasz, Jakub; Cieśla, Michał; Machaliński, Bogusław

    2017-09-26

    Bulk physicochemical properties of neurotrophin 4 (NT-4) in electrolyte solutions and its adsorption/desorption on/from mica surfaces have been studied using dynamic light scattering (DLS), microelectrophoresis, a solution depletion technique (enzyme-linked immunosorbent assay, ELISA), and AFM imaging. Our study presents a determination of the diffusion coefficient, hydrodynamic diameters, electrophoretic mobility, and isoelectric point of the NT-4 under various ionic strength and pH conditions. The size of the NT-4 homodimer for an ionic strength of 0.015 M was substantially independent of pH and equal to 5.1 nm. It has been found that the number of electrokinetic charges per NT-4 molecule was equal to zero for all studied ionic strengths at pH 8.1, which was identified as the isoelectric point (iep). The protein adsorption/desorption on/from mica surfaces was examined as a function of ionic strength and pH. The kinetics of neurotrophin adsorption/desorption were evaluated at pH 3.5, 7.4, and 11 by direct AFM imaging and the ELISA technique. A monotonic increase in the maximum coverage of adsorbed NT-4 molecules with ionic strength (up to 5.5 mg/m 2 ) was observed at pH 3.5. These results were interpreted in terms of the theoretical model postulating an irreversible adsorption of the protein governed by the random sequential adsorption (RSA). Our measurements revealed a significant role of ionic strength, pH, and electrolyte composition in the lateral electrostatic interactions among differently charged NT-4 molecules. The transition between adsorption/desorption processes is found for the region of high pH and low surface concentration of adsorbed neurotrophin molecules at constant ionic strength. Additionally, results presented in this work show that the adsorption behavior of neurotrophin molecules may be governed by intrasolvent electrostatic interactions yielding an aggregation process. Understanding polyvalent neurotrophin interactions may have an impact on

  12. Formation of H- ions via vibrational excited molecules produced from recombinative wall desorption of H atoms in a low-pressure H/sub 2/ positive column

    NARCIS (Netherlands)

    Amorim, J.; Loureiro, J.; Schram, D.C.

    2001-01-01

    Recombinative wall desorption of hydrogen atoms in a low-pressure hydrogen positive column leading to formation of H/sub 2/ (X/sup 1/ Sigma /sub g//sup +/, v) molecules in optimum levels for H/sup -/ production by dissociative attachment is investigated. We employed a kinetic model that solves the

  13. Electrothermal adsorption and desorption of volatile organic compounds on activated carbon fiber cloth

    Energy Technology Data Exchange (ETDEWEB)

    Son, H.K. [Department of Health and Environment, Kosin University, Dong Sam Dong, Young Do Gu, Busan (Korea, Republic of); Sivakumar, S., E-mail: ssivaphd@yahoo.com [Department of Bioenvironmental Energy, College of Natural Resource and Life Science, Pusan National University, Miryang-si, Gyeongsangnam-do 627-706 (Korea, Republic of); Rood, M.J. [Department of Civil and Environmental Engineering, University of Illinois, Urbana, IL (United States); Kim, B.J. [Construction Engineering Research Laboratory, U.S. Army Engineer Research and Development Center (ERDC-CERL), Champaign, IL (United States)

    2016-01-15

    Highlights: • We study the adsorption and desorption of VOCs by an activated carbon fiber cloth. • Desorption concentration was controlled via electrothermal heating. • The desorption rate was successfully equalized and controlled by this system. - Abstract: Adsorption is an effective means to selectively remove volatile organic compounds (VOCs) from industrial gas streams and is particularly of use for gas streams that exhibit highly variable daily concentrations of VOCs. Adsorption of such gas streams by activated carbon fiber cloths (ACFCs) and subsequent controlled desorption can provide gas streams of well-defined concentration that can then be more efficiently treated by biofiltration than streams exhibiting large variability in concentration. In this study, we passed VOC-containing gas through an ACFC vessel for adsorption and then desorption in a concentration-controlled manner via electrothermal heating. Set-point concentrations (40–900 ppm{sub v}) and superficial gas velocity (6.3–9.9 m/s) were controlled by a data acquisition and control system. The results of the average VOC desorption, desorption factor and VOC in-and-out ratio were calculated and compared for various gas set-point concentrations and superficial gas velocities. Our results reveal that desorption is strongly dependent on the set-point concentration and that the VOC desorption rate can be successfully equalized and controlled via an electrothermal adsorption system.

  14. Impact of activated carbon, biochar and compost on the desorption and mineralization of phenanthrene in soil

    International Nuclear Information System (INIS)

    Marchal, Geoffrey; Smith, Kilian E.C.; Rein, Arno; Winding, Anne; Wollensen de Jonge, Lis; Trapp, Stefan; Karlson, Ulrich G.

    2013-01-01

    Sorption of PAHs to carbonaceous soil amendments reduces their dissolved concentrations, limiting toxicity but also potentially biodegradation. Therefore, the maximum abiotic desorption of freshly sorbed phenanthrene (≤5 mg kg −1 ) was measured in three soils amended with activated carbon (AC), biochar or compost. Total amounts of phenanthrene desorbed were similar between the different soils, but the amendment type had a large influence. Complete desorption was observed in the unamended and compost amended soils, but this reduced for biochar (41% desorbed) and AC (8% desorbed). Cumulative amounts mineralized were 28% for the unamended control, 19% for compost, 13% for biochar and 4% for AC. Therefore, the effects of the amendments in soil in reducing desorption were also reflected in the extents of mineralization. Modeling was used to analyze key processes, indicating that for the AC and charcoal treatments bacterial activity did not limit mineralization, but rather desorption into the dissolved phase. -- Highlights: •Phenanthrene desorption and mineralization compared in soils with activated carbon, charcoal or compost. •Only activated charcoal and biochar hindered both desorption and mineralization. •A linear relationship was found between the extents desorbed and mineralized. •Modelling indicated that bacterial activity was not limiting but that desorption was. -- Extraction into an exhaustive silicone sink measures the maximum phenanthrene desorption from soils with amendments, and this is reflected in the extent of mineralization

  15. Preparation of Sm2Fe17-xGaxNy/Cy magnets by a hydrogenation-disproportionation-desorption-recombination process

    International Nuclear Information System (INIS)

    Kubis, M.; Cao, L.; Handstein, A.; Gebel, B.; Mueller, K.; Schultz, L.

    1997-01-01

    A hydrogenation-disproportionation-desorption-recombination process (HDDR) was applied to Sm 2 Fe 17-x Ga x (x=0.5, 1, and 2). The process was studied by means of temperature-pressure analysis, x-ray diffraction and scanning electron microscopy. It was shown that Ga not only stabilizes the interstitially modified compounds Sm 2 Fe 17-x Ga x C y (0 2 Fe 17-x Ga x against the disproportionation by hydrogen. Therefore, only for x=0.5 can a nearly complete HDDR be performed. The HDDR-treated and subsequently nitrogenated or carburized samples show coercivities μ 0J H C up to 3.1 T and 2.5 T, respectively. Hot compaction increases the density of the Sm 2 Fe 16.5 Ga 0.5 C y powder; however, it leads to a loss of coercivity due to decomposition into α-iron and samarium carbides. copyright 1997 American Institute of Physics

  16. Effect Of The Desorption-Recombination Temperature On The Microstructure And Magnetic Properties Of HDDR Processed Nd-Fe-B Powders

    Directory of Open Access Journals (Sweden)

    Lee J.-G.

    2015-06-01

    Full Text Available The effect of the desorption-recombination temperature on the microstructure and magnetic properties of hydrogenation-disproportionation-desorption-recombination (HDDR processed Nd-Fe-B powders was studied. The NdxB6.4Ga0.3Nb0.2Febal (x=12.5-13.5, at.% casting alloys were pulverized after homogenizing annealing, and then subjected to HDDR treatment. During the HDDR process, desorption-recombination (DR reaction was induced at two different temperature, 810°C and 820°C. The higher Nd content resulted in enhanced coercivity of the HDDR powder, and which was attributed to the thicker and more uniform Nd-rich phase along grain boundaries. But this uniform Nd-rich phase induced faster grain growth. The remanence of the powder DR-treated at 820°C is higher than that DR-treated at 810°C. In addition, it was also confirmed that higher DR temperature is much more effective to improve squareness.

  17. Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, 1

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1984-01-01

    An investigation was carried out on the desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent by the batch process. The rate of desorption of uranium with acidic eluent depended on temperature, showing an increase as the temperature was raised. But the rate of desorption with acidic eluent was less dependent on temperature than that obtained when mixed eluent of sodium carbonate-sodium hydrogencarbonate was used. The rate of desorption of uranium did not vary in the range of concentration from 0.3 to 0.5 N, and the rate of desorption with sulfuric acid was slightly higher than that obtained when hydrochloric acid was used. The amount of dissolved titanium decreased as the ratio of adsorbent to eluent (RAE) was increased. At RAE of 10 %, the percentage of dissolved titanium (DTI) was below 0.38 % with sulfuric acid, below 0.7 % with hydrochloric acid. These values were found to be higher than the ones with the carbonate eluent. The elements except uranium, which were adsorbed on the adsorbent, were eluted simultaneously with acidic eluent. The regeneration of the adsorbent after desorption, therefore, was found to be unnecessary. In a repeated test of adsorption-desorption treatment up to five times, the percentage of uranium adsorbed from natural sea water was approximately constant of 85 %. From these results, the application of column process to the desorption of uranium with acidic eluent at room temperature was proposed to be feasible. (author)

  18. Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, (1)

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1983-01-01

    An investigation was carried out on the desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent by the batch process. The rate of desorption of uranium with acidic eluent depended on temperature, showing an increase as the temperature was raised. But the rate of desorption with acidic eluent was less dependent on temperature than that obtained when mixed eluent of sodium carbonate-sodium hydrogencarbonate was used. The difference of the rate of desorption of uranium in the range of concentration from 0.3 to 0.5N was not found, and the rate of desorption with sulfuric acid was slightly higher than that obtained when hydrochloric acid was used. The amount of dissolved titanium decreased as the ratio of adsorbent to eluent (RAE) was increased. At RAE of 10%, the percentage of dissolved titanium (DTI) was below 0.38% with sulfuric acid, below 0.7% with hydrochloric acid. These values were found to be higher than the ones with the carbonate eluent. The elements except uranium, which were adsorbed on the adsorbent, were eluted simultaneously with acidic eluent. The regeneration of the adsorbent after desorption, therefore, was found to be unnecessary. In a repeated test of adsorption-desorption treatment up to five times, the percentage of uranium adsorbed from natural sea water was approximately constant of 85%. From these results, the application of column process to the desorption of uranium with acidic eluent at room temperature was proposed to be feasible. (author)

  19. Anti-proliferative activity of recombinant melittin expressed in ...

    African Journals Online (AJOL)

    Recombinant melittin was then successfully expressed in Escherichia coli. The activity of affinity-purified recombinant melittin was determined in human leukemic U937 cells. Results show that the recombinant melittin had the same anti-proliferative activity in human leukemic U937 cells in vitro as natural one. This shows the ...

  20. Effect of hydrogenation disproportionation conditions on magnetic anisotropy in Nd-Fe-B powder prepared by dynamic hydrogenation disproportionation desorption recombination

    Directory of Open Access Journals (Sweden)

    Masao Yamazaki

    2017-05-01

    Full Text Available Various anisotropic Nd-Fe-B magnetic powders were prepared by the dynamic hydrogenation disproportionation desorption recombination (d-HDDR treatment with different hydrogenation disproportionation (HD times (tHD. The resulting magnetic properties and microstructural changes were investigated. The magnetic anisotropy was decreased with increasing tHD. In the d-HDDR powders with higher magnetic anisotropy, fine (200–600 nm and coarse (600–1200 nm Nd2Fe14B grains were observed. The coarse Nd2Fe14B grains showed highly crystallographic alignment of the c-axis than fine Nd2Fe14B grains. In the highly anisotropic Nd2Fe14B d-HDDR powder, a large area fraction of lamellar-like structures consisting of NdH2 and α-Fe were observed after HD treatment. Furthermore, the mean diameter of the lamellar-like regions, where lamellar-like structures orientate to the same direction in the HD-treated alloys was close to that of coarse Nd2Fe14B grains after d-HDDR treatment. Thus, the lamellar-like regions were converted into the crystallographically aligned coarse Nd2Fe14B grains during desorption recombination treatment, and magnetic anisotropy is closely related to the volume fraction of lamellar-like regions observed after HD treatment.

  1. Electrospray ionization and matrix assisted laser desorption/ionization mass spectrometry: powerful analytical tools in recombinant protein chemistry

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Svensson, B; Roepstorff, P

    1996-01-01

    Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy is presen......Electrospray ionization and matrix assisted laser desorption/ionization are effective ionization methods for mass spectrometry of biomolecules. Here we describe the capabilities of these methods for peptide and protein characterization in biotechnology. An integrated analytical strategy...... is presented encompassing protein characterization prior to and after cloning of the corresponding gene....

  2. Recombinant ArtinM activates mast cells.

    Science.gov (United States)

    Barbosa-Lorenzi, Valéria Cintra; Cecilio, Nerry Tatiana; de Almeida Buranello, Patricia Andressa; Pranchevicius, Maria Cristina; Goldman, Maria Helena S; Pereira-da-Silva, Gabriela; Roque-Barreira, Maria Cristina; Jamur, Maria Célia; Oliver, Constance

    2016-07-04

    Mast cells are hematopoietically derived cells that play a role in inflammatory processes such as allergy, as well as in the immune response against pathogens by the selective and rapid release of preformed and lipid mediators, and the delayed release of cytokines. The native homotetrameric lectin ArtinM, a D-mannose binding lectin purified from Artocarpus heterophyllus seeds, is one of several lectins that are able to activate mast cells. Besides activating mast cells, ArtinM has been shown to affect several biological responses, including immunomodulation and acceleration of wound healing. Because of the potential pharmacological application of ArtinM, a recombinant ArtinM (rArtinM) was produced in Escherichia coli. The current study evaluated the ability of rArtinM to induce mast cell degranulation and activation. The glycan binding specificity of rArtinM was similar to that of jArtinM. rArtinM, via its CRD, was able to degranulate, releasing β-hexosaminidase and TNF-α, and to promote morphological changes on the mast cell surface. Moreover, rArtinM induced the release of the newly-synthesized mediator, IL-4. rArtinM does not have a co-stimulatory effect on the FcεRI degranulation via. The IgE-dependent mast cell activation triggered by rArtinM seems to be dependent on NFkB activation. The lectin rArtinM has the ability to activate and degranulate mast cells via their CRDs. The present study indicates that rArtinM is a suitable substitute for the native form, jArtinM, and that rArtinM may serve as an important and reliable pharmacological agent.

  3. Adsorption and desorption of pertechnetate on activated carbon

    International Nuclear Information System (INIS)

    Dano, M.; Galambos, M.; Rajec, P.; Viglasova, E.; Krajnak, A.; Novak, I.

    2014-01-01

    High surface area, a microporous structure, and a high degree of surface reactivity make activated carbons versatile adsorbents, particularly effective in the adsorption of radionuclides from aqueous solutions. The most important property of activated carbon, the property that determines its usage, is the pore structure. The total number of pores, their shape and size determine the adsorption capacity and even the dynamic adsorption rate of the activated carbon. This report is dedicated to sorption properties of new activated carbon sorbents. (authors)

  4. Comparing the desorption and biodegradation of low concentrations of phenanthrene sorbed to activated carbon, biochar and compost

    DEFF Research Database (Denmark)

    Marchal, Geoffrey; Smith, Kilian E.C.; Rein, Arno

    2013-01-01

    can be degraded at all, the desorption and biodegradation of low concentrations of 14C-labelled phenanthrene (⩽5μgL−1) freshly sorbed to suspensions of the pure soil amendments activated carbon (AC), biochar (charcoal) and compost were compared. Firstly, the maximum abiotic desorption of phenanthrene...

  5. Electrothermal Desorption of CWA Simulants from Activated Carbon Cloth

    National Research Council Canada - National Science Library

    Sullivan, Patrick D; Wander, Joseph D; Newsome, Kolin C

    2006-01-01

    The use of activated carbon fabrics (ACFs) that are desorbed electrothermally, also known as the Joule effect, is explored as a potential method to create a regenerating chemical warfare agent (CWA) filter...

  6. Localization of an O-glycosylated site in the recombinant barley alpha-amylase 1 produced in yeast and correction of the amino acid sequence using matrix-assisted laser desorption/ionization mass spectrometry of peptide mixtures

    DEFF Research Database (Denmark)

    Andersen, Jens S.; Søgaard, M; Svensson, B

    1994-01-01

    Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) of peptide mixtures was used to characterize recombinant barley alpha-amylase 1, produced in yeast. Three peptide mixtures were generated by cleavage with CNBr, digestion with endoproteinase Lys-C and Asp-N, respectively...

  7. Desorption, partitioning, and dechlorination characteristics of PCBs in sediments in interaction with reactive activated carbon.

    Science.gov (United States)

    Choi, Hyeok; Lawal, Wasiu; Al-Abed, Souhail R

    2015-04-28

    Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Hydrogen desorption reactions of Li-N-H hydrogen storage system: Estimation of activation free energy

    International Nuclear Information System (INIS)

    Matsumoto, Mitsuru; Haga, Tetsuya; Kawai, Yasuaki; Kojima, Yoshitsugu

    2007-01-01

    The dehydrogenation reactions of the mixtures of lithium amide (LiNH 2 ) and lithium hydride (LiH) were studied under an Ar atmosphere by means of temperature programmed desorption (TPD) technique. The dehydrogenation reaction of the LiNH 2 /LiH mixture was accelerated by addition of 1 mol% Ti(III) species (k = 3.1 x 10 -4 s -1 at 493 K), and prolonged ball-milling time (16 h) further enhanced reaction rate (k = 1.1 x 10 -3 s -1 at 493 K). For the hydrogen desorption reaction of Ti(III) doped samples, the activation energies estimated by Kissinger plot (95 kJ mol -1 ) and Arrhenius plot (110 kJ mol -1 ) were in reasonable agreement. The LiNH 2 /LiH mixture without Ti(III) species, exhibited slower hydrogen desorption process and the kinetic traces deviated from single exponential behavior. The results indicated the Ti(III) additives change the hydrogen desorption reaction mechanism of the LiNH 2 /LiH mixture

  9. Desorption, partitioning, and dechlorination characteristics of PCBs in sediments in interaction with reactive activated carbon

    International Nuclear Information System (INIS)

    Choi, Hyeok; Lawal, Wasiu; Al-Abed, Souhail R.

    2015-01-01

    Highlights: • Problematic aged real PCBs-contaminated sediment (WHS) was examined. • Performance of reactive activated carbon (RAC) impregnated with Pd–ZVI was tested. • Fate and transport of PCBs bound to WHS in the presence of RAC was fully traced. • Direct mixing configuration was compared with compartment configuration. • Results reflected real world complexities associated with slow desorption of PCBs. - Abstract: Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls

  10. Desorption, partitioning, and dechlorination characteristics of PCBs in sediments in interaction with reactive activated carbon

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hyeok, E-mail: hchoi@uta.edu [Department of Civil Engineering, The University of Texas at Arlington, 416 Yates Street, Arlington, TX 76019-0308 (United States); Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049 (United States); Lawal, Wasiu [Environmental and Earth Sciences Program, The University of Texas at Arlington, 500 Yates Street, Arlington, TX 76019-0049 (United States); Al-Abed, Souhail R. [National Risk Management Research Laboratory, U.S. Environmental Protection Agency, 26 W. Martin Luther King Dr., Cincinnati, OH 45268 (United States)

    2015-04-28

    Highlights: • Problematic aged real PCBs-contaminated sediment (WHS) was examined. • Performance of reactive activated carbon (RAC) impregnated with Pd–ZVI was tested. • Fate and transport of PCBs bound to WHS in the presence of RAC was fully traced. • Direct mixing configuration was compared with compartment configuration. • Results reflected real world complexities associated with slow desorption of PCBs. - Abstract: Sediment (WHS) in Waukegan Harbor, Illinois, heavily contaminated and aged with polychlorinated biphenyls (PCBs), was treated with reactive activated carbon (RAC) impregnated with palladized iron nanoparticles. Lab test proceeded in a direct mixing configuration of RAC and WHS. A compartment configuration, where RAC was physically separated from WHS, was also designed to trace the sequential transport and fate of PCBs, including desorption, adsorption, dechlorination, and re-partitioning. PCBs, once desorbed from WHS, were immediately sequestrated to RAC and subject to dechlorination. Direct mixing of WHS with RAC was one-order of magnitude more effective for dechlorination than compartment configuration. Compared to their desorption-followed by-adsorption route, direct physical contact of RAC with PCBs bound to WHS exhibited negligible contribution to the availability of PCBs for dechlorination reaction. Addition of RAC even in compartment configuration facilitated PCBs desorption from WHS. However, slow desorption of PCBs limited overall performance, resulting in a five-order of magnitude lower dechlorination yield when compared with treatment of purely aqueous PCBs. The low dechlorination yield reflected real world complexities in treating 3.19% organic carbon-containing WHS aged with PCBs for 40 years. These observations were further supported when compared with results on clean Cesar Creek sediment spiked with 2-chlorinated biphenyls.

  11. Activity of recombinant factor VIIa under different conditions in vitro

    DEFF Research Database (Denmark)

    Bladbjerg, Else-Marie; Jespersen, Jørgen

    2008-01-01

    Recombinant activated factor VII (NovoSeven; Novo Nordisk A/S, Måløv, Denmark) is an effective drug for treatment of bleeding in patients with haemophilia A or B and inhibitors. Little is known about physiological conditions influencing the efficacy of recombinant activated factor VII. We...... investigated the in-vitro effects of pH, temperature, and haemodilution on the activity of recombinant activated factor VII. Samples from eight healthy volunteers were spiked with recombinant activated factor VII (final concentration 1.7 microg/ml) and adjusted to pH 6.0, 6.5, 7.0, and 7.4 or analysed at 30......, 33, 37, and 40 degrees C, or diluted 0, 10, 20, 40, and 60% with dextran before analysis. Samples were analysed as rotational thromboelastometry in whole blood (clotting time, clot formation time, and maximum clot firmness) with and without Innovin (tissue factor), and as factor VII coagulant...

  12. Recombiner

    International Nuclear Information System (INIS)

    Kikuchi, Nobuo.

    1983-01-01

    Purpose: To shorten the pre-heating time for a recombiner and obtain a uniform temperature distribution for the charged catalyst layer in a BWR type reactor. Constitution: A pre-heating heater is disposed to the outer periphery of a vessel for a recombiner packed with catalysts for recombining hydrogen and oxygen in gases flowing through a radioactive gaseous wastes processing system. Heat pipes for transmitting the heat applied to said container to the catalyst are disposed vertically and horizontally within the container. Different length of the heat pipes are combined. In this way, pre-heating time for the recombiner before the operation start and before the system switching can be shortened and the uniform pre-heating for the inside of the recombiner is also made possible. Further, heater control in the pre-heating can be carried out effectively and with ease. (Moriyama, K.)

  13. Recombiner

    International Nuclear Information System (INIS)

    Osumi, Morimichi.

    1979-01-01

    Purpose: To provide a recombiner which is capable of converting hydrogen gas into water by use of high-frequency heating at comparatively low temperatures and is safe and cheap in cost. Constitution: Hydrogen gas is introduced from an outer pipeline to the main structure of a recombiner, and when it passes through the vicinity of the central part of the recombiner, it is reacted with copper oxide (CuO 2 ) heated to a temperature more than 300 0 C by a high-frequency heater, and converted gently into water by reduction operation (2H 2 + CuO 2 → Cu + 2H 2 O). The thus prepared water is exhausted through the outer pipeline to a suppression pool. A part of hydrogen gas which has not been converted completely into water by the reaction and is remaining as hydrogen is recovered through exhaust nozzles and again introduced into the main structure of the recombiner. (Yoshino, Y.)

  14. Prdm9 Controls Activation of Mammalian Recombination Hotspots

    OpenAIRE

    Parvanov, Emil D.; Petkov, Petko M.; Paigen, Kenneth

    2009-01-01

    Mammalian meiotic recombination, which preferentially occurs at specialized sites called hotspots, assures the orderly segregation of meiotic chromosomes and creates genetic variation among offspring. A locus on mouse Chr 17, that controls activation of recombination at multiple distant hotspots, has been mapped within a 181 Kb interval, three of whose genes can be eliminated as candidates. The remaining gene, Prdm9, codes for a zinc finger containing histone H3K4 trimethylase that is uniquel...

  15. Behaviors and kinetics of toluene adsorption-desorption on activated carbons with varying pore structure.

    Science.gov (United States)

    Yang, Xi; Yi, Honghong; Tang, Xiaolong; Zhao, Shunzheng; Yang, Zhongyu; Ma, Yueqiang; Feng, Tiecheng; Cui, Xiaoxu

    2018-05-01

    This work was undertaken to investigate the behaviors and kinetics of toluene adsorption and desorption on activated carbons with varying pore structure. Five kinds of activated carbon from different raw materials were selected. Adsorption isotherms and breakthrough curves for toluene were measured. Langmuir and Freundlich equations were fitted to the equilibrium data, and the Freundlich equation was more suitable for simulating toluene adsorption. The process consisted of monolayer, multilayer and partial active site adsorption types. The effect of the pore structure of the activated carbons on toluene adsorption capacity was investigated. The quasi-first-order model was more suitable for describing the process than the quasi-second-order model. The adsorption data was also modeled by the internal particle diffusion model and it was found that the adsorption process could be divided into three stages. In the external surface adsorption process, the rate depended on the specific surface area. During the particle diffusion stage, pore structure and volume were the main factors affecting adsorption rate. In the final equilibrium stage, the rate was determined by the ratio of meso- and macro-pores to total pore volume. The rate over the whole adsorption process was dominated by the toluene concentration. The desorption behavior of toluene on activated carbons was investigated, and the process was divided into heat and mass transfer parts corresponding to emission and diffusion mechanisms, respectively. Physical adsorption played the main role during the adsorption process. Copyright © 2017. Published by Elsevier B.V.

  16. Antiproliferative activity of recombinant human interferon-λ2 ...

    African Journals Online (AJOL)

    Antiproliferative activity of recombinant human interferon-λ2 expressed in stably ... The representing 26 kDa protein band of IFN-λ2 was detected by SDS-PAGE and ... The antiproliferative activity of hIFN-λ2 was determined by MTT assay.

  17. Deuterium retention and desorption behavior in an advanced reduced-activation alloy

    Energy Technology Data Exchange (ETDEWEB)

    Noh, S.J., E-mail: sjnoh@dankook.ac.kr [Department of Applied Physics, Dankook University, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of); Kim, H.S.; Byeon, W.J.; Shin, H.W. [Department of Applied Physics, Dankook University, Yongin-si, Gyeonggi-do 448-701 (Korea, Republic of); Lee, Cheol Eui [Department of Physics, Korea University, Seoul 136-713 (Korea, Republic of); Lee, S.K. [Nuclear Fusion Development Division, Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

    2017-07-15

    We present the first experimental results of the deuterium retention and desorption behavior in an advanced reduced-activation alloy (ARAA) under development in Korea. For the in-situ measurement of desorbed gases from samples immediately after irradiation, a thermal desorption spectroscopy (TDS) system clustered with an inductively coupled plasma ion source has been built. Samples were and were not irradiated with helium ions at energies of 1.4, 3.5, and 5.0 keV and then continuously irradiated with 1.7-keV deuterium ions. TDS measurements were performed in situ immediately after deuterium irradiation and after exposure to air for one week. The amount of desorbed deuterium is the largest for the sample without helium irradiation from the TDS results measured in situ immediately after irradiation. Further, the amount of desorbed deuterium is significantly lowered when the helium energy is increased to 3.5 keV with no significant changes thereafter, indicating that the layer formed by implanted helium at near or deeper than the stopping range for 1.7-keV deuterium ions effectively acts as a barrier against deuterium diffusion into the depth. Because of the strong diffusivity of deuterium into the ambient atmosphere, the amounts of desorbed deuterium are greatly reduced for the samples without helium irradiation and with 1.4-keV helium irradiation after exposure to air for one week. In addition, our deuterium results for the ARAA are also compared with the results for F82H by other authors. - Highlights: •The first result of the deuterium retention and desorption in an ARAA is presented. •The ARAA was irradiated with helium and then continuously irradiated with deuterium. •TDS measurements were performed in situ immediately after deuterium irradiation. •TDS measurements were performed after exposure to air for one week. •The effects of helium irradiation and exposure to air were investigated.

  18. Study of chlordecone desorption from activated carbons and subsequent dechlorination by reduced cobalamin.

    Science.gov (United States)

    Ranguin, Ronald; Durimel, Axelle; Karioua, Reeka; Gaspard, Sarra

    2017-11-01

    Since 1972, the French departments of Guadeloupe and Martinique have intensively used organochlorinated pesticides such as chlordecone (CLD) and hexachlorocyclohexane (HCH) isomers to prevent the proliferation of banana weevil (Cosmopolite sordidus). These molecules are stable in the environment, leading to a continuous contamination of soils, water, and food chain in the banana-producing areas. In these polluted areas, water treatment plants are equipped with activated carbon (AC) filters. In order to improve treatment of CLD-contaminated waters by AC, CLD adsorption and desorption kinetic studies are carried out using different ACs produced from sugar cane bagasse as adsorbents and subsequent CLD degradation is performed using reduced vitamin B12 (VB12). A GC-MS method for CLD quantification is as well optimized. This study shows that bagasse ACs are able to capture the pollutant, leading to a CLD concentration decrease from 1 to 73 μg L -1 , with an adsorption capacity of 162 μg mg -1 . Adsorption capacity increase with the temperature indicates an endothermic process. Polar solvents favor CLD desorption from ACs, suggesting hydrogen bonding between CLD and surface groups of ACs, the best solvent for chemical desorption being ethanol. Subsequent degradation of CLD in ethanol is performed using vitamin B12 reduced by either 1,4-dithiotreitol (DTT) or zerovalent zinc, leading to 90% of CLD removal and to the molecule cage structure opening for formation of a pentachloroindene intermediate product, characterized by GC MS/MS. A pathway for pentachloroindene formation from CLD is proposed.

  19. Recombiner

    International Nuclear Information System (INIS)

    Saalfrank, H.

    1985-01-01

    Air containing hydrogen can be oxidized by heating in a container called a recombiner, in order to avoid the collection of hydrogen. The container is long and a large number of straight heating bars are arranged in parallel in it and they are flanged to a lid. The heating bars are surrounded by tubes, in order to obtain good heat transfer by a narrow annular gap. (orig.) [de

  20. Hydrogenation-disproportionation-desorption-recombination in Sm2Fe16M (M=Al, Ga and Si) and magnetic properties of their carburized powders

    International Nuclear Information System (INIS)

    Kubis, M.; Rave, W.; Cao, L.; Gebel, B.; Mueller, K.-H.; Schultz, L.

    1998-01-01

    The application of the hydrogenation-disproportionation-desorption-recombination (HDDR) process in Sm 2 Fe 16 M (M=Al,Ga and Si) was investigated. The hydrogen absorption behaviour was studied by temperature-pressure analysis (TPA). In the temperature range between 500 and 800 C, Sm 2 Fe 16 M samples with M=Ga and Si show a weaker hydrogen absorption than Sm 2 Fe 16 Al. This was confirmed by X-ray diffraction which showed a complete disproportionation of Sm 2 Fe 16 Al into SmH z (1.9 2 Fe 16 Ga and Sm 2 Fe 16 Si exhibit a fraction of undecomposed material with the Th 2 Zn 17 -type structure after the disproportionation procedure. These results point to a stabilization of Sm 2 Fe 16 M against disproportionation by hydrogen for M=Ga and Si. The magnetization processes of carburized HDDR powders were studied by VSM measurements and Kerr microscopy. The demagnetization curve of our HDDR processed Sm 2 Fe 16 AlC y is well shaped, whereas those of Sm 2 Fe 16 GaC y and Sm 2 Fe 16 SiC y show a large decrease of the polarization at low fields. The favourable behaviour of Sm 2 Fe 16 AlC y is due to a homogeneous submicron grain structure. In Sm 2 Fe 16 GaC y and Sm 2 Fe 16 SiC y samples, an additional, magnetically soft phase with larger domains was observed which causes the low coercivity. As a consequence, HDDR was only favourable for the preparation of Sm 2 Fe 16 MC y hard magnets with M=Al but not for M=Ga and Si. Optimization of the HDDR process in Sm 2 Fe 16 Al and subsequent nitrogenation or carburization led to coercivities of μ 0j H c =2.9 and 2.5 T, respectively. (orig.)

  1. Modeling of hydrogen desorption from tungsten surface

    Energy Technology Data Exchange (ETDEWEB)

    Guterl, J., E-mail: jguterl@ucsd.edu [University of California, San Diego, La Jolla, CA 92093 (United States); Smirnov, R.D. [University of California, San Diego, La Jolla, CA 92093 (United States); Krasheninnikov, S.I. [University of California, San Diego, La Jolla, CA 92093 (United States); Nuclear Research National University MEPhI, Moscow 115409 (Russian Federation); Uberuaga, B.; Voter, A.F.; Perez, D. [Los Alamos National Laboratory, Los Alamos, NM 8754 (United States)

    2015-08-15

    Hydrogen retention in metallic plasma-facing components is among key-issues for future fusion devices. For tungsten, which has been chosen as divertor material in ITER, hydrogen desorption parameters experimentally measured for fusion-related conditions show large discrepancies. In this paper, we therefore investigate hydrogen recombination and desorption on tungsten surfaces using molecular dynamics simulations and accelerated molecular dynamics simulations to analyze adsorption states, diffusion, hydrogen recombination into molecules, and clustering of hydrogen on tungsten surfaces. The quality of tungsten hydrogen interatomic potential is discussed in the light of MD simulations results, showing that three body interactions in current interatomic potential do not allow to reproduce hydrogen molecular recombination and desorption. Effects of surface hydrogen clustering on hydrogen desorption are analyzed by introducing a kinetic model describing the competition between surface diffusion, clustering and recombination. Different desorption regimes are identified and reproduce some aspects of desorption regimes experimentally observed.

  2. Anti-proliferative activity of recombinant melittin expressed in ...

    African Journals Online (AJOL)

    kesiena

    2012-02-09

    Feb 9, 2012 ... 44 amino acid residues mediated by dipeptidylpeptidase. IV (Vlasak et al., 1983). It has been reported that the melittin exhibits antimicrobial activity and pro- ... Construction of recombinant expression vector. A pair of complementary oligonucleotides named Mel-1 (5′-GAT. CCG GAA TTG GAG CAG TTC ...

  3. Prdm9 controls activation of mammalian recombination hotspots.

    Science.gov (United States)

    Parvanov, Emil D; Petkov, Petko M; Paigen, Kenneth

    2010-02-12

    Mammalian meiotic recombination, which preferentially occurs at specialized sites called hotspots, ensures the orderly segregation of meiotic chromosomes and creates genetic variation among offspring. A locus on mouse chromosome 17, which controls activation of recombination at multiple distant hotspots, has been mapped within a 181-kilobase interval, three of whose genes can be eliminated as candidates. The remaining gene, Prdm9, codes for a zinc finger containing histone H3K4 trimethylase that is expressed in early meiosis and whose deficiency results in sterility in both sexes. Mus musculus exhibits five alleles of Prdm9; human populations exhibit two predominant alleles and multiple minor alleles. The identification of Prdm9 as a protein regulating mammalian recombination hotspots initiates molecular studies of this important biological control system.

  4. A novel clot lysis assay for recombinant plasminogen activator.

    Science.gov (United States)

    Jamialahmadi, Oveis; Fazeli, Ahmad; Hashemi-Najafabadi, Sameereh; Fazeli, Mohammad Reza

    2015-03-01

    Recombinant plasminogen activator (r-PA, reteplase) is an engineered variant of alteplase. When expressed in E. coli, it appears as inclusion bodies that require refolding to recover its biological activity. An important step following refolding is to determine the activity of refolded protein. Current methods for enzymatic activity of thrombolytic drugs are costly and complex. Here a straightforward and low-cost clot lysis assay was developed. It quantitatively measures the activity of the commercial reteplase and is also capable of screening refolding conditions. As evidence for adequate accuracy and sensitivity of the current assay, r-PA activity measurements are shown to be comparable to those obtained from chromogenic substrate assay.

  5. Study of desorption of methyl iodide from activated carbon impregnated by TEDA

    International Nuclear Information System (INIS)

    Yue Longqing; Luo Deli; Yue Ziyu

    2013-01-01

    The capability of iodine retention is an important parameter of solid sorbent, iodine could be desorbed from activated carbon once the parameter doesn't meet requirement. This work discussed the effects of nitrogen flow rate, dipping in water, temperature and K + on the iodine retention. The results show, the quantities of iodine released increase to 3.15 times when nitrogen flow rates increase from 0.1 m 3 /h to 1.5 m 3 /h; methyl iodine molecules are desorbed after half of an hour's dipping in water with no notable change observed thereafter to the desorption capacity at l.5 h, 2 h, 3 h, 4 h respectively; there was no release of iodine below 80 ℃; K + play a positive role for retention of iodine species; and that the quantities of methyl iodine released with 0.06 g KCl account for 56% of that without KCl. (authors)

  6. Desorption of Reactive Red 198 from activated carbon prepared from walnut shells: effects of temperature, sodium carbonate concentration and organic solvent dose

    Directory of Open Access Journals (Sweden)

    Zohreh Alimohamadi

    2017-04-01

    Full Text Available This study investigated the effect of temperature, different concentrations of sodium carbonate,and the dose of organic solvent on the desorption of Reactive Red 198 dye from dye-saturated activated carbon using batch and continuous systems. The results of the batch desorption test showed 60% acetone in water as the optimum amount. However, when the concentration of sodium carbonate was raised, the dye desorption percentage increased from 26% to 42% due to economic considerations; 15 mg/L of sodium carbonate was selected to continue the processof desorption. Increasing the desorption temperature can improve the dye desorption efficiency.According to the column test results, dye desorption concentration decreased gradually with the passing of time. The column test results showed that desorption efficiency and the percentage of dye adsorbed decreased; however, it seemed to stabilize after three repeated adsorption/desorption cycles. The repeated adsorption–desorption column tests (3 cycles showed that the activated carbon which was prepared from walnut shell was a suitable and economical adsorbent for dye removal.

  7. [Adsorption and desorption of dyes by waste-polymer-derived activated carbons].

    Science.gov (United States)

    Lian, Fei; Liu, Chang; Li, Guo-Guang; Liu, Yi-Fu; Li, Yong; Zhu, Ling-Yan

    2012-01-01

    Mesoporous activated carbons with high surface area were prepared from three waste polymers, i. e., tire rubber, polyvinyl chloride (PVC) and polyethyleneterephtalate (PET), by KOH activation. The adsorption/desorption characteristics of dyes (methylene blue and methyl orange) on the carbons were studied. The effects of pH, ionic strength and surface surfactants in the solution on the dye adsorption were also investigated. The results indicated that the carbons derived from PVC and PET exhibited high surface area of 2 666 and 2 831 m2 x g(-1). Their mesopore volume were as high as 1.06 and 1.30 cm3 g(-1), respectively. 98.5% and 97.0% of methylene blue and methyl orange were removed in 15 min by PVC carbon, and that of 99.5% and 95.0% for PET carbon. The Langmuir maximum adsorption capacity to these dyes was more than 2 mmol x g(-1), much higher than that of commercial activated carbon F400. Compared with Freundlich model, the adsorption data was fitted better by Langmiur model, indicating monolayer coverage on the carbons. The adsorption was highly dependent on solution pH, ionic strength and concentration of surface surfactants. The activated carbons exhibited higher adsorption to methylene blue than that of methyl orange, and it was very hard for both of the dyes to be desorbed. The observation in this study demonstrated that activated carbons derived from polymer waste could be effective adsorbents for the treatment of wastewater with dyes.

  8. 4-MCHM sorption to and desorption from granular activated carbon and raw coal.

    Science.gov (United States)

    Jeter, T Scott; Sarver, Emily A; McNair, Harold M; Rezaee, Mohammad

    2016-08-01

    4-Methylcyclohexanemethanol (4-MCHM) is a saturated higher alicyclic primary alcohol that is used in the froth flotation process for cleaning coal. In early 2014, a large spill of crude chemical (containing primarily 4-MCHM) to the Elk River near Charleston, WV contaminated the local water supply. Carbon filters at the affected water treatment facility quickly became saturated, and the contaminated water was distributed to nearby homes and businesses. Sorption of 4-MCHM to granular activated carbon (GAC) was studied in the laboratory using head space (HS) analysis via gas chromatography with a flame ionization detector (GC-FID). Sorption to raw coal was also investigated, since this material may be of interest as a sorbent in the case of an on-site spill. As expected, sorption to both materials increased with decreased particle size and with increased exposure time; although exposure time proved to be much more important in the case of GAC than for coal. Under similar conditions, GAC sorbed more 4-MCHM than raw coal (e.g., 84.9 vs. 63.1 mg/g, respectively, for 20 × 30 mesh particles exposed to 860 mg/L 4-MCHM solution for 24 h). Desorption from both materials was additionally evaluated. Interestingly, desorption of 4-MCHM on a mass per mass basis was also higher for GAC than for raw coal. Overall, results indicated that GAC readily sorbs 4-MCHM but can also readily release a portion of the chemical, whereas coal sorbs somewhat less 4-MCHM but holds it tightly. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Hydrogenation-disproportionation-desorption-recombination in Sm{sub 2}Fe{sub 16}M (M=Al, Ga and Si) and magnetic properties of their carburized powders

    Energy Technology Data Exchange (ETDEWEB)

    Kubis, M.; Rave, W.; Cao, L.; Gebel, B.; Mueller, K.-H.; Schultz, L. [Institut fuer Festkoerper- und Werkstofforschung Dresden e.V. (Germany)

    1998-11-20

    The application of the hydrogenation-disproportionation-desorption-recombination (HDDR) process in Sm{sub 2}Fe{sub 16}M (M=Al,Ga and Si) was investigated. The hydrogen absorption behaviour was studied by temperature-pressure analysis (TPA). In the temperature range between 500 and 800 C, Sm{sub 2}Fe{sub 16}M samples with M=Ga and Si show a weaker hydrogen absorption than Sm{sub 2}Fe{sub 16}Al. This was confirmed by X-ray diffraction which showed a complete disproportionation of Sm{sub 2}Fe{sub 16}Al into SmH{sub z} (1.9

  10. [Harvest of the carbon source in wastewater by the adsorption and desorption of activated sludge].

    Science.gov (United States)

    Liu, Hong-Bo; Wen, Xiang-Hua; Zhao, Fang; Mei, Yi-Jun

    2011-04-01

    The carbon source in municipal wastewater was adsorbed by activated sludge and then harvested through the hydrolysis of activated sludge. Results indicated that activated sludge had high absorbing ability towards organic carbon and phosphorus under continuous operation mode, and the average COD and TP absorption rate reached as high as 63% and 76%, respectively. Moreover, about 50% of the soluble carbon source was outside of the sludge cell and could be released under mild hydrolysis condition. Whereas the absorbed amount of nitrogen was relatively low, and the removal rate of ammonia was only 13% . Furthermore, the releases of organic carbon, nitrogen and phosphorus from the sludge absorbing pollutants in the wastewater were studied. By comparing different hydrolysis conditions of normal (pH 7.5, 20 degrees C), heating (pH 7.5, 60 degrees C) and the alkaline heating (pH 11, 60 degrees C), the last one presented the optimum hydrolysis efficiency. Under which, the release rate of COD could reach 320 mg/g after 24 hours, whereas nitrogen and phosphorus just obtained low release rates of 18 mg/g and 2 mg/g, respectively. Results indicate that the carbon source in wastewater could be harvested by the adsorption and desorption of activated sludge, and the concentrations of nitrogen and phosphorus are low and would not influence the reuse of the harvested carbon source.

  11. Using microwave heating to improve the desorption efficiency of high molecular weight VOC from beaded activated carbon.

    Science.gov (United States)

    Fayaz, Mohammadreza; Shariaty, Pooya; Atkinson, John D; Hashisho, Zaher; Phillips, John H; Anderson, James E; Nichols, Mark

    2015-04-07

    Incomplete regeneration of activated carbon loaded with organic compounds results in heel build-up that reduces the useful life of the adsorbent. In this study, microwave heating was tested as a regeneration method for beaded activated carbon (BAC) loaded with n-dodecane, a high molecular weight volatile organic compound. Energy consumption and desorption efficiency for microwave-heating regeneration were compared with conductive-heating regeneration. The minimum energy needed to completely regenerate the adsorbent (100% desorption efficiency) using microwave regeneration was 6% of that needed with conductive heating regeneration, owing to more rapid heating rates and lower heat loss. Analyses of adsorbent pore size distribution and surface chemistry confirmed that neither heating method altered the physical/chemical properties of the BAC. Additionally, gas chromatography (with flame ionization detector) confirmed that neither regeneration method detectably altered the adsorbate composition during desorption. By demonstrating improvements in energy consumption and desorption efficiency and showing stable adsorbate and adsorbent properties, this paper suggests that microwave heating is an attractive method for activated carbon regeneration particularly when high-affinity VOC adsorbates are present.

  12. Perchlorate adsorption and desorption on activated carbon and anion exchange resin.

    Science.gov (United States)

    Yoon, In-Ho; Meng, Xiaoguang; Wang, Chao; Kim, Kyoung-Woong; Bang, Sunbaek; Choe, Eunyoung; Lippincott, Lee

    2009-05-15

    The mechanisms of perchlorate adsorption on activated carbon (AC) and anion exchange resin (SR-7 resin) were investigated using Raman, FTIR, and zeta potential analyses. Batch adsorption and desorption results demonstrated that the adsorption of perchlorate by AC and SR-7 resin was reversible. The reversibility of perchlorate adsorption by the resin was also proved by column regeneration test. Solution pH significantly affected perchlorate adsorption and the zeta potential of AC, while it did not influence perchlorate adsorption and the zeta potential of resin. Zeta potential measurements showed that perchlorate was adsorbed on the negatively charged AC surface. Raman spectra indicated the adsorption resulted in an obvious position shift of the perchlorate peak, suggesting that perchlorate was associated with functional groups on AC at neutral pH through interactions stronger than electrostatic interaction. The adsorbed perchlorate on the resin exhibited a Raman peak at similar position as the aqueous perchlorate, indicating that perchlorate was adsorbed on the resin through electrostatic attraction between the anion and positively charged surface sites.

  13. Desorption of uranium from titanium-activated carbon composite adsorbent with acidic eluent, 2

    International Nuclear Information System (INIS)

    Hirotsu, Takahiro; Fujii, Ayako; Sakane, Kohji; Katoh, Shunsaku; Sugasaka, Kazuhiko

    1984-01-01

    The desorption of uranium from the granular titanium-activated carbon composite adsorbent (concentration of uranium: 25.5 mg/1-Ad), which adsorbed uranium from natural sea water, was examined by the column process with acidic eluent at room temperature. The column operation was able to be carried out without destruction of the granular adsorbent by the generation of the carbon dioxide, and free from disturbance of the eluent flow by precipitate of calcium sulfate dihydrate with sulfuric acid eluent. The amount of acid consumption by the adsorbent was 0.87 eq/1-Ad. The alkaline earth metals were eluted in the range of elution volume below 2 1/1-Ad, whereas uranium, iron, and titanium were eluted above 2 1/1-Ad. Therefore, uranium was separable from the alkaline earth metals which were adsorbed in the most quantity in the adsorbent. In the range of elution volume 2 to 12 1/1-Ad, the percentage of desorbed uranium and the concentration ratio of uranium were 80 %, 680 with 0.5 N sulfuric acid, and 59 %, 490 with 0.5 N hydrochloric acid, respectively. The percentage of dissolved titanium (DTI) was 0.3 % with 0.5 N sulfuric acid, 0.26 % with 0.5 N hydrochloric acid in the same range. (author)

  14. The effect of activated carbon on partitioning, desorption, and biouptake of native polychlorinated biphenyls in four freshwater sediments.

    Science.gov (United States)

    Sun, Xueli; Ghosh, Upal

    2008-11-01

    The present study evaluated the effect of activated carbon amendment in four freshwater sediments from the Great Lakes (North America) areas of concern with a wide range of sediment geochemical characteristics (0.83-5.1% total organic carbon) and polychlorinated biphenyl (PCB) concentrations (0.33-84.7 microg/g). The work focused on understanding the impact of activated carbon amendment on PCB aqueous partitioning, PCB desorption characteristics, and PCB biouptake in a freshwater oligochaete (Lumbriculus variegatus). The results showed that PCB aqueous equilibrium concentrations, rapid desorption fractions, and biouptake by the oligochaete were reduced after activated carbon amendment. Addition of activated carbon at a dose of 0.5-fold native organic carbon reduced PCB bioaccumulation by 42% for Niagara River sediment, 85% for Grasse River sediment, 74% for Milwaukee River sediment 1, and 70% for Milwaukee River sediment 2. A linear relationship was observed between log biota-sediment accumulation factor and the first 6-h desorption fractions for each PCB homologue for treated and untreated sediments. Water-lipid bioconcentration factors for PCB congeners were largely conserved after amendment with activated carbon. Our present results suggest that at steady state, changes in the aqueous PCB concentrations can be used to predict changes in PCB bioaccumulation in deposit-feeding organisms. Thus, use of advanced pore-water measurement techniques, such as solid-phase extraction passive samplers, may be suitable for long-term monitoring of treatment performance.

  15. Impact of activated carbon, biochar and compost on the desorption and mineralization of phenanthrene in soil

    DEFF Research Database (Denmark)

    Marchal, Geoffrey; Smith, Kilian E.C.; Rein, Arno

    2013-01-01

    ), biochar or compost. Total amounts of phenanthrene desorbed were similar between the different soils, but the amendment type had a large influence. Complete desorption was observed in the unamended and compost amended soils, but this reduced for biochar (41% desorbed) and AC (8% desorbed). Cumulative...... amounts mineralized were 28% for the unamended control, 19% for compost, 13% for biochar and 4% for AC. Therefore, the effects of the amendments in soil in reducing desorption were also reflected in the extents of mineralization. Modeling was used to analyze key processes, indicating that for the AC...

  16. Recombination activating activity of XRCC1 analogous genes in X-ray sensitive and resistant CHO cell lines

    International Nuclear Information System (INIS)

    Golubnitchaya-Labudova, O.; Hoefer, M.; Portele, A.; Vacata, V.; Rink, H.; Lubec, G.

    1997-01-01

    The XRCC1 gene (X-ray repair cross complementing) complements the DNA repair deficiency of the radiation sensitive Chinese hamster ovary (CHO) mutant cell line EM9 but the mechanism of the correction is not elucidated yet. XRCC1 shows substantial homology to the RAG2 gene (recombination activating gene) and we therefore tried to answer the question, whether structural similarities (sequence of a putative recombination activating domain, aa 332-362 for XRCC1 and aa 286-316 in RAG2) would reflect similar functions of the homologous, putative recombination activating domain. PCR experiments revealed that no sequence homologous to the structural part of human XRCC1 was present in cDNA of CHO. Differential display demonstrated two putative recombination activating in the parental CHO line AA8 and one in the radiosensitive mutant EM9. Southern blot experiments showed the presence of several genes with partial homology to human XRCC1. Recombination studies consisted of expressing amplified target domains within chimeric proteins in recA - bacteria and subsequent detection of recombination events by sequencing the recombinant plasmids. Recombination experiments demonstrated recombination activating activity of all putative recombination activating domains amplified from AA8 and EM9 genomes as reflected by deletions within the inserts of the recombinant plasmids. The recombination activating activity of XRCC1 analogues could explain a mechanism responsible for the correction of the DNA repair defect in EM9. (author)

  17. Mechanism of action of recombinant activated factor VII: an update.

    Science.gov (United States)

    Hedner, Ulla

    2006-01-01

    Bleeding episodes in patients with hemophilia and inhibitors must be managed using agents that are hemostatically active in the absence of factor VIII or IX. Activated prothrombin complex concentrates have long been used in this context. However, the search for safer and more effective agents has led to the development of recombinant activated factor VII (rFVIIa; NovoSeven, Novo Nordisk, Bagsvaerd, Denmark). This paper presents an update on the mechanism of action of rFVIIa, and describes how pharmacologic doses of this agent enhance thrombin production and thus contribute to the development of a stable, lysis-resistant fibrin plug at the site of vessel damage. This mechanism explains the reported efficacy of rFVIIa in a range of clinical situations characterized by impaired thrombin generation.

  18. Production of biologically active recombinant human factor H in Physcomitrella.

    Science.gov (United States)

    Büttner-Mainik, Annette; Parsons, Juliana; Jérôme, Hanna; Hartmann, Andrea; Lamer, Stephanie; Schaaf, Andreas; Schlosser, Andreas; Zipfel, Peter F; Reski, Ralf; Decker, Eva L

    2011-04-01

    The human complement regulatory serum protein factor H (FH) is a promising future biopharmaceutical. Defects in the gene encoding FH are associated with human diseases like severe kidney and retinal disorders in the form of atypical haemolytic uremic syndrome (aHUS), membranoproliferative glomerulonephritis II (MPGN II) or age-related macular degeneration (AMD). There is a current need to apply intact full-length FH for the therapy of patients with congenital or acquired defects of this protein. Application of purified or recombinant FH (rFH) to these patients is an important and promising approach for the treatment of these diseases. However, neither protein purified from plasma of healthy individuals nor recombinant protein is currently available on the market. Here, we report the first stable expression of the full-length human FH cDNA and the subsequent production of this glycoprotein in a plant system. The moss Physcomitrella patens perfectly suits the requirements for the production of complex biopharmaceuticals as this eukaryotic system not only offers an outstanding genetical accessibility, but moreover, proteins can be produced safely in scalable photobioreactors without the need for animal-derived medium compounds. Transgenic moss lines were created, which express the human FH cDNA and target the recombinant protein to the culture supernatant via a moss-derived secretion signal. Correct processing of the signal peptide and integrity of the moss-produced rFH were verified via peptide mapping by mass spectrometry. Ultimately, we show that the rFH displays complement regulatory activity comparable to FH purified from plasma. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  19. Sorption and desorption of the industrial chemical MCHM into polymer pipes, liners and activated carbon

    OpenAIRE

    Ahart, Megan Leanne

    2015-01-01

    Polyethylene pipes and epoxy or polyurethane linings are increasingly used in drinking water infrastructure. As a recent introduction to the water industry, there are still many unknowns about how polymers will behave in the distribution system specifically relating to sorption and desorption of chemical contaminants. This study is in response to a spill of 4-methylcyclohexane methanol (MCHM) that occurred in January 2014 contaminating the drinking water of nine counties in West Virginia. Thi...

  20. Recombinant activated factor VII: 30 years of research and innovation.

    Science.gov (United States)

    Hedner, Ulla

    2015-06-01

    Recombinant activated factor VII (rFVIIa) was initially developed to treat bleeding episodes in patients with congenital haemophilia and inhibitors. The story of its development began in the 1970s, when FVIIa was identified as one of the activated coagulation factors that has minimal potential for inducing thromboembolic side-effects. Extensive research over the last 30 years has greatly increased our knowledge of the characteristics of FVII, its activation, and the mechanisms by which rFVIIa restores haemostasis. In haemophilia, the haemostatic effect of rFVIIa is mediated via binding to thrombin-activated platelets at the site of injury, thereby enhancing thrombin generation also in the absence of factor (F) VIII or FIX. The mechanism of action of rFVIIa has also allowed its successful use in other clinical scenarios characterised by impaired thrombin generation, and its licensed uses have now been extended to acquired haemophilia, congenital FVII deficiency and Glanzmann's thrombasthenia. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Permanent Genetic Access to Transiently Active Neurons via TRAP: Targeted Recombination in Active Populations

    OpenAIRE

    Guenthner, Casey J.; Miyamichi, Kazunari; Yang, Helen H.; Heller, H. Craig; Luo, Liqun

    2013-01-01

    Targeting genetically encoded tools for neural circuit dissection to relevant cellular populations is a major challenge in neurobiology. We developed a new approach, Targeted Recombination in Active Populations (TRAP), to obtain genetic access to neurons that were activated by defined stimuli. This method utilizes mice in which the tamoxifen-dependent recombinase CreERT2 is expressed in an activity-dependent manner from the loci of the immediate early genes Arc and Fos. Active cells that expr...

  2. Evidence supporting the use of recombinant activated factor VII in congenital bleeding disorders

    DEFF Research Database (Denmark)

    Johansson, Pär I; Ostrowski, Sisse R

    2010-01-01

    Recombinant activated factor VII (rFVIIa, NovoSeven) was introduced in 1996 for the treatment of hemophilic patients with antibodies against coagulation factor VIII or IX.......Recombinant activated factor VII (rFVIIa, NovoSeven) was introduced in 1996 for the treatment of hemophilic patients with antibodies against coagulation factor VIII or IX....

  3. Recombinant activated factor VII in cardiac surgery: single-center experience.

    Science.gov (United States)

    Singh, Sarvesh Pal; Chauhan, Sandeep; Choudhury, Minati; Malik, Vishwas; Choudhary, Shiv Kumar

    2014-02-01

    The widespread off-label use of recombinant activated factor VII for the control of refractory postoperative hemorrhage continues despite a warning from the Food and Drug Administration. Although effective in reducing the need for transfusion of blood and blood products, safety concerns still prevail. To compare the dosing and efficacy of recombinant activated factor VII between pediatric and adult patients, and in the operating room and intensive care unit. The records of 69 patients (33 children and 36 adults) who underwent cardiovascular surgery and received recombinant activated factor VII were reviewed retrospectively. The dose of recombinant activated factor VII, mediastinal drainage, use of blood and blood products, incidence of thrombosis, and 28-day mortality were studied. the efficacy of recombinant activated factor VII was comparable in adults and children, despite the lower dose in adults. Prophylactic use of recombinant activated factor VII decreased the incidence of mediastinal exploration and the duration of intensive care unit stay. A 4.3% incidence of thrombotic complications was observed in this study. The efficacious dose of recombinant activated factor VII is much less in adults compared to children. Prophylactic use of recombinant activated factor VII decreases the dose required, the incidence of mediastinal exploration, and intensive care unit stay, with no survival benefit.

  4. Studying of the standardization principles of pharmacological activity of recombinant erythropoietin preparations

    OpenAIRE

    A. K. Yakovlev; L. A. Gayderova; N. A. Alpatova; T. N. Lobanova; E. L. Postnova; E. I. Yurchikova; T. A. Batuashvili; R. A. Volkova; V. N. Podkuiko; Yu. V. Olefir

    2016-01-01

    Analysis of the publications devoted to the structure, functions, mechanism of action of erythropoietin is given in the article. Erythropoietin preparations derived from recombinant DNA technology are a mixture of isoforms with different biological activity, which determine the biological properties pharmacological activity, pharmacokinetics, efficacy and safety of medicinal product. Erythropoietin preparations derived by using recombinant DNA technology are a mixture of isoforms with differe...

  5. Improving of understanding of beta-hexachlorocyclohexane (HCH) adsorption on activated carbons by temperature-programmed desorption studies.

    Science.gov (United States)

    Passé-Coutrin, Nady; Maisonneuve, Laetitia; Durimel, Axelle; Dentzer, Joseph; Gadiou, Roger; Gaspard, Sarra

    2016-01-01

    In order to understand the interactions between beta-hexachlorocyclohexane (HCH) and chemical groups at activated carbon (AC) surface, the solid samples were hydrogenated aiming to decrease the amounts of oxygenated groups. Two AC samples designated by BagH2O and BagP1.5 were prepared by water vapor activation and phosphoric acid activation, respectively, of sugarcane bagasse used as an AC precursor. A more simple molecule 1,2,3-trichloropropane (TCP) is used as a model of chlorinated compound. The AC were characterized by infrared, X-ray photoelectron spectroscopy (XPS), Raman resonance spectroscopies, as well as temperature-programmed desorption coupled with mass spectrometry (TPD-MS). BagP1.5 and BagH2O AC surface contained oxygenated groups. Upon hydrogenation, a decrease of most of these group amxounts was observed for both samples, while hydroxyl groups increased. On the basis of temperature-programmed desorption data obtained for AC samples contaminated with TCP or HCH, it was possible to determine the type of hydrogen bond formed between each AC and HCH.

  6. In-situ regeneration of activated carbon with electric potential swing desorption (EPSD) for the H2S removal from biogas.

    Science.gov (United States)

    Farooq, M; Almustapha, M N; Imran, M; Saeed, M A; Andresen, John M

    2018-02-01

    In-situ regeneration of a granular activated carbon was conducted for the first time using electric potential swing desorption (EPSD) with potentials up to 30 V. The EPSD system was compared against a standard non-potential system using a fixed-bed reactor with a bed of 10 g of activated carbon treating a gas mixture with 10,000 ppm H 2 S. Breakthrough times, adsorption desorption volume, capacities, effect of regeneration and desorption kinetics were investigated. The analysis showed that desorption of H 2 S using the new EPSD system was 3 times quicker compared with the no potential system. Hence, physical adsorption using EPSD over activated carbon is efficient, safe and environmental friendly and could be used for the in-situ regeneration of granular activated carbon without using a PSA and/or TSA system. Additionally, adsorption and desorption cycles can be obtained with a classical two column system, which could lead towards a more efficient and economic biogas to biomethane process. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Proteolytic activity of recombinant DegP from Chromohalobacter salexigens BKL5

    Directory of Open Access Journals (Sweden)

    Dewi Fitriani

    2017-09-01

    Conclusions: Recombinant DegP from C. salexigens BKL5 showed proteolytic activity when β-casein was used as a substrate. In silico analysis indicated that recombinant DegP had characteristics similar to those of halophilic proteins depending on its amino acid composition.

  8. In-situ regeneration of activated carbon with electric potential swing desorption (EPSD) for the H2S removal from biogas

    DEFF Research Database (Denmark)

    Farooq, M.; Almustapha, M. N.; Imran, Muhammad

    2017-01-01

    , physical adsorption using EPSD over activated carbon is efficient, safe and environmental friendly and could be used for the in-situ regeneration of granular activated carbon without using a PSA and/or TSA system. Additionally, adsorption and desorption cycles can be obtained with a classical two column...... system, which could lead towards a more efficient and economic biogas to biomethane process....

  9. (111)Indium Labelling of Recombinant Activated Coagulation Factor VII

    DEFF Research Database (Denmark)

    Nalla, Amarnadh; Buch, Inge; Sigvardt, Maibritt

    2012-01-01

    The aim of this study is to investigate whether (111)Indium-labelled recombinant FVIIa (rFVIIa) could be a potential radiopharmaceutical for localization of bleeding sources. DTPA-conjugated rFVIIa was radiolabelled with (111)In chloride. In vitro binding efficiency of (111)In-DTPA-rFVIIa to F1A2...

  10. New insights into the evolutionary origins of the recombination-activating gene proteins and V(D)J recombination.

    Science.gov (United States)

    Carmona, Lina Marcela; Schatz, David G

    2017-06-01

    The adaptive immune system of jawed vertebrates relies on V(D)J recombination as one of the main processes to generate the diverse array of receptors necessary for the recognition of a wide range of pathogens. The DNA cleavage reaction necessary for the assembly of the antigen receptor genes from an array of potential gene segments is mediated by the recombination-activating gene proteins RAG1 and RAG2. The RAG proteins have been proposed to originate from a transposable element (TE) as they share mechanistic and structural similarities with several families of transposases and are themselves capable of mediating transposition. A number of RAG-like proteins and TEs with sequence similarity to RAG1 and RAG2 have been identified, but only recently has their function begun to be characterized, revealing mechanistic links to the vertebrate RAGs. Of particular significance is the discovery of ProtoRAG, a transposon superfamily found in the genome of the basal chordate amphioxus. ProtoRAG has many of the sequence and mechanistic features predicted for the ancestral RAG transposon and is likely to be an evolutionary relative of RAG1 and RAG2. In addition, early observations suggesting that RAG1 is able to mediate V(D)J recombination in the absence of RAG2 have been confirmed, implying independent evolutionary origins for the two RAG genes. Here, recent progress in identifying and characterizing RAG-like proteins and the TEs that encode them is summarized and a refined model for the evolution of V(D)J recombination and the RAG proteins is presented. © 2016 Federation of European Biochemical Societies.

  11. 78 FR 27977 - Office of Biotechnology Activities; Recombinant DNA Research: Proposed Actions Under the NIH...

    Science.gov (United States)

    2013-05-13

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... Recombinant or Synthetic Nucleic Acid Molecules (NIH Guidelines) SUMMARY: The NIH Office of Biotechnology... of Biotechnology Activities, National Institutes of Health, 6705 Rockledge Drive, Suite 750, Bethesda...

  12. 75 FR 31795 - Office of Biotechnology Activities; Recombinant DNA Research: Amended Notice of Meeting

    Science.gov (United States)

    2010-06-04

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology Activities; Recombinant DNA Research: Amended Notice of Meeting ACTION: Notice of cancellation of... information. Dated: May 26, 2010. Jacqueline Corrigan-Curay, Acting Director, Office of Biotechnology...

  13. Permanent genetic access to transiently active neurons via TRAP: targeted recombination in active populations.

    Science.gov (United States)

    Guenthner, Casey J; Miyamichi, Kazunari; Yang, Helen H; Heller, H Craig; Luo, Liqun

    2013-06-05

    Targeting genetically encoded tools for neural circuit dissection to relevant cellular populations is a major challenge in neurobiology. We developed an approach, targeted recombination in active populations (TRAP), to obtain genetic access to neurons that were activated by defined stimuli. This method utilizes mice in which the tamoxifen-dependent recombinase CreER(T2) is expressed in an activity-dependent manner from the loci of the immediate early genes Arc and Fos. Active cells that express CreER(T2) can only undergo recombination when tamoxifen is present, allowing genetic access to neurons that are active during a time window of less than 12 hr. We show that TRAP can provide selective access to neurons activated by specific somatosensory, visual, and auditory stimuli and by experience in a novel environment. When combined with tools for labeling, tracing, recording, and manipulating neurons, TRAP offers a powerful approach for understanding how the brain processes information and generates behavior. Copyright © 2013 Elsevier Inc. All rights reserved.

  14. Synthesis of a new low-cost activated carbon from activated sludge for the removal of Cr (Ⅵ) from aqueous solution: Equilibrium, kinetics, thermodynamics and desorption studies

    Energy Technology Data Exchange (ETDEWEB)

    Gorzin, Fatemeh; Ghoreyshi, Ali Asghar [Babol University of Technology, Babol (Iran, Islamic Republic of)

    2013-08-15

    Elimination of Cr (Ⅵ) from aqueous solution was investigated by a new low cost activated carbon developed from aerobically digested activated sludge (ADAS). The adsorbent demonstrated remarkable characteristics such as high surface area of 760m{sup 2}·g{sup −1} and large total pore volume of 0.8383 cm{sup 3}·g{sup −1}. The maximum equilibrium uptake of Cr (Ⅵ) was 70.15 mg·g{sup −1} at optimum pH 2.0. Interpretation of equilibrium data revealed that the best description was provided by the Freundlich isotherm. The kinetics of Cr (Ⅵ) adsorption was well described by the pseudo-second order equation. Calculation of thermodynamic parameters revealed that the adsorption process was endothermic, spontaneous and feasible.. The adsorbent was regenerated using NaOH and it was found to be suitable for reuse in successive adsorption-desorption cycles. The desorption efficiency of Cr (Ⅵ) ion was up to 78%. Finally, comparison of Cr (Ⅵ) adsorption capacity of the developed adsorbent with commercial activated carbon demonstrated its higher performance.

  15. Recombinant dioscorins of the yam storage protein expressed in Escherichia coli exhibit antioxidant and immunomodulatory activities.

    Science.gov (United States)

    Jheng, Yi-Jyun; Tsai, Wei-Yi; Chen, Kuo-Hsuan; Lin, Kuo-Wei; Chyan, Chia-Lin; Yang, Ching-Chi; Lin, Kuo-Chih

    2012-09-01

    Dioscorins, the major storage proteins in yam tubers, exhibit biochemical and immunomodulatroy activities. To investigate the potential application of dioscorins in biomedical research, we expressed the dioscorin genes Dj-dioA3 and Dp-dioA2 from Dioscorea japonica and Dioscorea pseudojaponica, respectively, in E. coli and routinely obtained approximately 15 mg proteins per liter Escherichia coli culture (mg/L) to 30 mg/L of rDj-dioscorinA3 and 4 to 8 mg/L of rDp-dioscorinA2. Western blot analyses revealed that both recombinant dioscorins contained epitopes with similar antigenicities to those of the native dioscorins. Results from dithiothreitol (DTT) treatment followed by monobromobimane (mBBr) staining showed that both recombinant dioscorins, like the native dioscorins, contain an intramolecular disulfide bond between Cys(28) and Cys(187) residues. Circular dichroism spectroscopy findings indicated that the secondary structural contents of the recombinant dioscorins showed high similarity to those of their corresponding native dioscorins. Both recombinant dioscorins, like the native dioscorins, exhibited 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and Toll-like receptor 4 signaling activities, and stimulated the phagocytosis of E. coli by macrophage. Overall, our results indicated that substantial amounts of recombinant dioscorins can be purified easily from E. coli and that these recombinant dioscorins are appropriate for application in future investigations of the biomedical functions of dioscorins. Copyright © 2012 Elsevier Inc. All rights reserved.

  16. Effect of Temperature on the Desorption and Decomposition of GB on Activated Carbon

    National Research Council Canada - National Science Library

    Karwacki, Christopher

    1999-01-01

    ...) and its decomposition products on coconut shell activated carbon (CSC). The results show that, under equilibrium conditions on dry CSC, changes in the partial pressure of GB are affected primarily by its loading and temperature of the adsorbent...

  17. 75 FR 21008 - Office of Biotechnology Activities; Recombinant DNA Research: Proposed Actions Under the NIH...

    Science.gov (United States)

    2010-04-22

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... Biotechnology Activities (OBA) published a proposal to revise the NIH Guidelines for Research with Recombinant... by fax to 301-496-9839 or mail to the Office of Biotechnology Activities, National Institutes of...

  18. Experimental study on removals of SO2 and NO(x) using adsorption of activated carbon/microwave desorption.

    Science.gov (United States)

    Ma, Shuang-Chen; Yao, Juan-Juan; Gao, Li; Ma, Xiao-Ying; Zhao, Yi

    2012-09-01

    Experimental studies on desulfurization and denitrification were carried out using activated carbon irradiated by microwave. The influences of the concentrations of nitric oxide (NO) and sulfur dioxide (SO2), the flue gas coexisting compositions, on adsorption properties of activated carbon and efficiencies of desulfurization and denitrification were investigated. The results show that adsorption capacity and removal efficiency of NO decrease with the increasing of SO2 concentrations in flue gas; adsorption capacity of NO increases slightly first and drops to 12.79 mg/g, and desulfurization efficiency descends with the increasing SO2 concentrations. Adsorption capacity of SO2 declines with the increasing of O2 content in flue gas, but adsorption capacity of NO increases, and removal efficiencies of NO and SO2 could be larger than 99%. Adsorption capacity of NO declines with the increase of moisture in the flue gas, but adsorption capacity of SO2 increases and removal efficiencies of NO and SO2 would be relatively stable. Adsorption capacities of both NO and SO2 decrease with the increasing of CO2 content; efficiencies of desulfurization and denitrification augment at the beginning stage, then start to fall when CO2 content exceeds 12.4%. The mechanisms of this process are also discussed. The prominent SO2 and NOx treatment techniques in power plants are wet flue gas desulfurization (FGD) and the catalytic decomposition method like selective catalytic reduction (SCR) or nonselective catalytic reduction (NSCR). However, these processes would have some difficulties in commercial application due to their high investment, requirement of expensive catalysts and large-scale equipment, and so on. A simple SO2 and NOx reduction utilizing decomposition by microwave energy method can be used. The pollutants control of flue gas in the power plants by the method of microwave-induced decomposition using adsorption of activated carbon/microwave desorption can meet the

  19. Characterization of DNA binding, transcriptional activation, and regulated nuclear association of recombinant human NFATp

    Directory of Open Access Journals (Sweden)

    Seto Anita G

    2000-11-01

    Full Text Available Abstract Background NFATp is one member of a family of transcriptional activators whose nuclear accumulation and hence transcriptional activity is regulated in mammalian cells. Human NFATp exists as a phosphoprotein in the cytoplasm of naive T cells. Upon antigen stimulation, NFATp is dephosphorylated, accumulates in nuclei, and functions to regulate transcription of genes including those encoding cytokines. While the properties of the DNA binding domain of NFATp have been investigated in detail, biochemical studies of the transcriptional activation and regulated association with nuclei have remained unexplored because of a lack of full length, purified recombinant NFATp. Results We developed methods for expressing and purifying full length recombinant human NFATp that has all of the properties known to be associated with native NFATp. The recombinant NFATp binds DNA on its own and cooperatively with AP-1 proteins, activates transcription in vitro, is phosphorylated, can be dephosphorylated by calcineurin, and exhibits regulated association with nuclei in vitro. Importantly, activation by recombinant NFATp in a reconstituted transcription system required regions of the protein outside of the central DNA binding domain. Conclusions We conclude that NFATp is a bona fide transcriptional activator. Moreover, the reagents and methods that we developed will facilitate future studies on the mechanisms of transcriptional activation and nuclear accumulation by NFATp, a member of an important family of transcriptional regulatory proteins.

  20. Antiproliferative activity of recombinant human interferon-λ2 ...

    African Journals Online (AJOL)

    Jane

    2011-07-20

    Jul 20, 2011 ... antiviral activity, antiproliferative activity and in vivo antitumor activity .... bovine serum albumin (BSA) and 0.05% (v/v) Tween 20 in PBS at room temperature for 1 h .... identified and developed into an important insect embryo.

  1. Effect of haemodilution, acidosis, and hypothermia on the activity of recombinant factor VIIa (NovoSeven)

    DEFF Research Database (Denmark)

    Viuff, D.; Lauritzen, B.; Pusateri, A.E.

    2008-01-01

    BACKGROUND: A range of plasma volume expanders is used clinically, often in settings where haemostasis may already be impaired. The haemostatic agent, recombinant activated factor VII (rFVIIa, NovoSeven), may be used to improve haemostasis but potential interactions with different volume expanders...

  2. Efficacy and safety of recombinant activated factor VII for acute intracerebral hemorrhage

    DEFF Research Database (Denmark)

    Mayer, Stephan A; Brun, Nikolai C; Begtrup, Kamilla

    2008-01-01

    BACKGROUND: Intracerebral hemorrhage is the least treatable form of stroke. We performed this phase 3 trial to confirm a previous study in which recombinant activated factor VII (rFVIIa) reduced growth of the hematoma and improved survival and functional outcomes. METHODS: We randomly assigned 841...

  3. EFFECT OF GRAIN SIZE AND ACTIVATION TIME OF ZEOLITE TO ADSORPTION AND DESORPTION OF NH4OH AND KCL AS MODEL OF FERTILIZER-ZEOLITE MIX

    Directory of Open Access Journals (Sweden)

    Muhammad Prasantio Bimantio

    2017-10-01

    Full Text Available Zeolites can be used as adsorbent, ion exchange, catalyst, or catalyst carrier. Application of fertilizer use in the zeolite also be one of the interesting topic. Zeolites in a mixture of fertilizer can use to control the release of nutrients. The purpose of this research is to study the effect of grain size and time of the activation of zeolite to adsorption and desorption of NH4OH and KCl as modeling of ZA and KCl fertilizer, to obtain the value of adsorption rate constant (ka and desorption rate constant (kd. This research procedure include: the process of adsorption by adding zeolite with various size and time of activation into a sealed beaker glass and let the adsorption process occurs for 24 hours. After 24 hours, the solution was filtered, the zeolite then put in 100 ml of aquadest into a sealed beaker glass and let the desorption process happened for another 24 hours. Three samples with the largest difference solution concentrations looked for the value of the ka and kd. Zeolite configuration with the largest ka is trialed with fertilizer and compared with the value of ka obtained from modeling. The result for NH4OH adsorbate, -50+60 mesh 2 hours configuration zeolite give the largest ka. For KCl adsorbate, -30+40 mesh 4 hours configuration zeolite give the largest ka. The value between modeling and trials with fertilizers are not much different.

  4. Sorption-Desorption Behavior of Newly synthesized N-(1H-Benzimidazole -2 ylmethyl) Acetamide (ABNZ) on Selected Soils and its Antifungal activity

    International Nuclear Information System (INIS)

    Ahmad, K. S.; Rashid, N.

    2015-01-01

    A batch equilibrium method has been utilized to investigate the adsorption-desorption behavior of a versatile commercially available fungicide N-(1H-benzimidazole-2ylmethyl) acetamide (ABNZ) on four Pakistani soils geographically distant, from hilly to desert areas. Both qualitative and quantitative analysis has been done for sorption-desorption behavior of ABNZ. These analyses are done in the different concentration of fungicide (0-0.25, 0.25-0.5, 0.5-0.75). Based on statistical analysis ABNZ execute the Freundlich adsorption isotherm in all four tested soils having values of slope n<1 resembling the L-type curve. The distribution co-efficient K/sub d(ads)/ ranges from (2.66 to 12.42 ml/meu g/sup -1/) indicating low adsorption of ABNZ overall. Sorption increases with soil organic carbon content, exhibited greater degree of adsorption for hilly soil and least adsorption on sandy soil of Multan, Punjab. Desorption studies reveal that the adsorbed fungicide is firmly retained by soil particles and present a certain degree of irreversibility. The results indicate that the soil organic matters followed by clay content are the most important soil properties governing the fungicide sorption capacity. Compound N-(1H- benzimidazole -2-ylmethyl) acetamide (ABNZ) showed maximum antifungal activity compared to rest of the tested compound. This anti-fungal activity is substantial in comparison to other pesticides. It causes 40% inhibition of Microsporum canis and Fusarium solani. (author)

  5. Effect of copper on the recombination activity of extended defects in silicon

    Energy Technology Data Exchange (ETDEWEB)

    Feklisova, O. V., E-mail: feklisov@iptm.ru; Yakimov, E. B. [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)

    2015-06-15

    The effect of copper atoms introduced by high-temperature diffusion on the recombination properties of dislocations and dislocation trails in p-type single-crystal silicon is studied by the electron-beam-induced current technique. It is shown that, in contrast to dislocations, dislocation trails exhibit an increase in recombination activity after the introduction of copper. Bright contrast appearance in the vicinity of dislocation trails is detected after the diffusion of copper and quenching of the samples. The contrast depends on the defect density in these trails.

  6. Anti-angiogenesis and anti-tumor activity of recombinant anginex

    International Nuclear Information System (INIS)

    Brandwijk, Ricardo J.M.G.E.; Dings, Ruud P.M.; Linden, Edith van der; Mayo, Kevin H.; Thijssen, Victor L.J.L.; Griffioen, Arjan W.

    2006-01-01

    Anginex, a synthetic 33-mer angiostatic peptide, specifically inhibits vascular endothelial cell proliferation and migration along with induction of apoptosis in endothelial cells. Here we report on the in vivo characterization of recombinant anginex and use of the artificial anginex gene for gene therapy approaches. Tumor growth of human MA148 ovarian carcinoma in athymic mice was inhibited by 80% when treated with recombinant anginex. Histological analysis of the tumors showed an approximate 2.5-fold reduction of microvessel density, suggesting that angiogenesis inhibition is the cause of the anti-tumor effect. Furthermore, there was a significant correlation between the gene expression patterns of 16 angiogenesis-related factors after treatment with both recombinant and synthetic anginex. To validate the applicability of the anginex gene for gene therapy, stable transfectants of murine B16F10 melanoma cells expressing recombinant anginex were made. Supernatants of these cells inhibited endothelial cell proliferation in vitro. Furthermore, after subcutaneous injection of these cells in C57BL/6 mice, an extensive delay in tumor growth was observed. These data show that the artificial anginex gene can be used to produce a recombinant protein with similar activity as its synthetic counterpart and that the gene can be applied in gene therapy approaches for cancer treatment

  7. High-Level Expression of Recombinant Bovine Lactoferrin in Pichia pastoris with Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Blanca Iglesias-Figueroa

    2016-06-01

    Full Text Available In this study, bovine lactoferrin (bLf, an iron-binding glycoprotein considered an important nutraceutical protein because of its several properties, was expressed in Pichia pastoris KM71-H under AOX1 promoter control, using pJ902 as the recombinant plasmid. Dot blotting analysis revealed the expression of recombinant bovine lactoferrin (rbLf in Pichia pastoris. After Bach fermentation and purification by molecular exclusion, we obtained an expression yield of 3.5 g/L of rbLf. rbLf and predominantly pepsin-digested rbLf (rbLfcin demonstrated antibacterial activity against Escherichia coli (E. coli BL21DE3, Staphylococcus aureus (S. aureus FRI137, and, in a smaller percentage, Pseudomonas aeruginosa (Ps. Aeruginosa ATCC 27833. The successful expression and characterization of functional rbLf expressed in Pichia pastoris opens a prospect for the development of natural antimicrobial agents produced recombinantly.

  8. Refolding techniques for recovering biologically active recombinant proteins from inclusion bodies.

    Science.gov (United States)

    Yamaguchi, Hiroshi; Miyazaki, Masaya

    2014-02-20

    Biologically active proteins are useful for studying the biological functions of genes and for the development of therapeutic drugs and biomaterials in a biotechnology industry. Overexpression of recombinant proteins in bacteria, such as Escherichia coli, often results in the formation of inclusion bodies, which are protein aggregates with non-native conformations. As inclusion bodies contain relatively pure and intact proteins, protein refolding is an important process to obtain active recombinant proteins from inclusion bodies. However, conventional refolding methods, such as dialysis and dilution, are time consuming and, often, recovered yields of active proteins are low, and a trial-and-error process is required to achieve success. Recently, several approaches have been reported to refold these aggregated proteins into an active form. The strategies largely aim at reducing protein aggregation during the refolding procedure. This review focuses on protein refolding techniques using chemical additives and laminar flow in microfluidic chips for the efficient recovery of active proteins from inclusion bodies.

  9. Topical application of recombinant activated factor VII during cesarean delivery for placenta previa.

    Science.gov (United States)

    Schjoldager, Birgit T B G; Mikkelsen, Emmeli; Lykke, Malene R; Præst, Jørgen; Hvas, Anne-Mette; Heslet, Lars; Secher, Niels J; Salvig, Jannie D; Uldbjerg, Niels

    2017-06-01

    During cesarean delivery in patients with placenta previa, hemorrhaging after removal of the placenta is often challenging. In this condition, the extraordinarily high concentration of tissue factor at the placenta site may constitute a principle of treatment as it activates coagulation very effectively. The presumption, however, is that tissue factor is bound to activated factor VII. We hypothesized that topical application of recombinant activated factor VII at the placenta site reduces bleeding without affecting intravascular coagulation. We included 5 cases with planned cesarean delivery for placenta previa. After removal of the placenta, the surgeon applied a swab soaked in recombinant activated factor VII containing saline (1 mg in 246 mL) to the placenta site for 2 minutes; this treatment was repeated once if the bleeding did not decrease sufficiently. We documented the treatment on video recordings and measured blood loss. Furthermore, we determined hemoglobin concentration, platelet count, international normalized ratio, activated partial thrombin time, fibrinogen (functional), factor VII:clot, and thrombin generation in peripheral blood prior to and 15 minutes after removal of the placenta. We also tested these blood coagulation variables in 5 women with cesarean delivery planned for other reasons. Mann-Whitney test was used for unpaired data. In all 5 cases, the uterotomy was closed under practically dry conditions and the median blood loss was 490 (range 300-800) mL. There were no adverse effects of recombinant activated factor VII and we did not measure factor VII to enter the circulation. Neither did we observe changes in thrombin generation, fibrinogen, activated partial thrombin time, international normalized ratio, and platelet count in the peripheral circulation (all P values >.20). This study indicates that in patients with placenta previa, topical recombinant activated factor VII may diminish bleeding from the placenta site without initiation

  10. [Expression and activity determination of recombinant capsid protein VP2 gene of enterovirus type 71].

    Science.gov (United States)

    Huang, Xueyong; Liu, Guohua; Hu, Xiaoning; Du, Yanhua; Li, Xingle; Xu, Yuling; Chen, Haomin; Xu, Bianli

    2014-04-01

    To clone and express the recombinant capsid protein VP2 of enterovirus type 71 (EV71) and to identify the immune activity of expressed protein in order to build a basis for the investigation work of vaccine and diagnostic antigen. VP2 gene of EV71 was amplified by PCR, and then was cut by restriction enzyme and inserted into expression vector pMAL-c2X. The positive recombinants were transferred into E.coli TB1, the genetically engineered bacteria including pMAL-c2X-VP2 plasmids were induced by isopropyl thiogalactoside ( IPTG) , and the expression products were analyzed by SDS-PAGE and western blotting method. EV71 IgM antibody detection method by ELISA was set up, and the sensitivity and specificity of this method was assessed; 60 neutralizing antibody positive serum samples from hand foot and mouth disease (HFMD) patients were determined, of which 52 samples were positive and 8 samples were negative; a total of 88 acute phase serum samples of HFMD patients diagnosed in clinical were also detected. VP2 gene of 762 bp was obtained by PCR, the gene segment inserted into the recombinant vector was identified using restriction enzyme digestion. The recombinant vector could express a specific about 71 500 fusion protein in E.coli by SDS-PAGE. The purified recombinant protein of EV71-VP2 can react with the serum of HFMD patients to produce a specific band by western blotting. The sensitivity and specificity of ELISA was 87% and 83%, respectively. Of the 88 acute phase serum samples from children with HFMD, 48 samples (55%) were positive by the ELISA assay. VP2 gene of EV71 has been cloned and a prokaryotic high expression system for VP2 gene was successfully constructed in the present study. The recombination EV71-VP2 has well antigenicity, which could be useful for developing diagnose reagent or vaccine of EV71.

  11. Use of thermal desorption gas chromatography-olfactometry/mass spectrometry for the comparison of identified and unidentified odor active compounds emitted from building products containing linseed oil

    DEFF Research Database (Denmark)

    Clausen, P. A.; Knudsen, Henrik Nellemose; Larsen, K.

    2008-01-01

    The emission of odor active volatile organic compounds (VOCs) from a floor oil based on linseed oil, the linseed oil itself and a low-odor linseed oil was investigated by thermal desorption gas chromatography combined with olfactometry and mass spectrometry (TD-GC-O/MS). The oils were applied...... to filters and conditioned in the micro emission cell, FLEC, for 1-3 days at ambient temperature, an air exchange rate of 26.9 h-1 and a 30% relative humidity. These conditions resulted in dynamic headspace concentrations and composition of the odor active VOCs that may be similar to real indoor setting...

  12. Recombinant cold-adapted attenuated influenza A vaccines for use in children: reactogenicity and antigenic activity of cold-adapted recombinants and analysis of isolates from the vaccinees.

    OpenAIRE

    Alexandrova, G I; Polezhaev, F I; Budilovsky, G N; Garmashova, L M; Topuria, N A; Egorov, A Y; Romejko-Gurko, Y R; Koval, T A; Lisovskaya, K V; Klimov, A I

    1984-01-01

    Reactogenicity and antigenic activity of recombinants obtained by crossing cold-adapted donor of attenuation A/Leningrad/134/47/57 with wild-type influenza virus strains A/Leningrad/322/79(H1N1) and A/Bangkok/1/79(H3N2) were studied. The recombinants were areactogenic when administered as an intranasal spray to children aged 3 to 15, including those who lacked or had only low titers of pre-existing anti-hemagglutinin and anti-neuraminidase antibody in their blood. After two administrations of...

  13. Effects of buffer agents on hydrogen adsorption and desorption at/within activated carbon for the negative electrode of aqueous asymmetric supercapacitors

    International Nuclear Information System (INIS)

    Chien, Hsiu-Chuan; Wu, Tzu-Ho; Rajkumar, Muniyandi; Hu, Chi-Chang

    2016-01-01

    Highlights: • H adsorption causes local pH increase and negatively shifts the double-layer potential window. • The local pH variation at AC/electrolyte interface can be controlled via adding buffer agents. • H adsorption potential on AC in buffer electrolytes follows the Nernstian dependence. • The pseudocapacitive reversibility of H adsorption/desorption at/within AC is too poor. - Abstract: In this work, the effects of adding buffer agents into aqueous electrolytes on the hydrogen adsorption/desorption behaviour at/within activated carbon are systematically investigated for the negative electrode of asymmetric supercapacitors. Due to the poor electrochemical reversibility of hydrogen adsorption/desorption at/within activated carbon, the hydrogen responses at/within activated carbon are not suitable for pseudo-capacitive energy storage of high-performance asymmetric supercapacitor. The electrochemical adsorption of H atoms consumes protons and causes the local pH change at the activated carbon/electrolyte interface, leading to the negative shift in the H adsorption potential when weakly acidic, neutral, and weakly basic electrolytes without buffer agents are employed. The addition of buffer agents into electrolytes significantly improves the rate of proton supply and promotes the rate of hydrogen adsorption at/within AC. Interestingly, the onset potential of significant H adsorption obtained from the buffered electrolytes generally follows the Nernstian dependence, suggesting the Nerstian dependence of H"+/H_a_d_s on AC at all pH values. In order to obtain the energy storage devices with high coulombic and energy efficiencies, the onset potential of significant H adsorption obtained from the electrolyte containing buffer agents is a reliable lower potential limit of the AC-coated negative electrode for aqueous asymmetric supercapacitors.

  14. Insecticidal activity of two proteases against Spodoptera frugiperda larvae infected with recombinant baculoviruses

    Science.gov (United States)

    2010-01-01

    Background Baculovirus comprise the largest group of insect viruses most studied worldwide, mainly because they efficiently kill agricutural insect pests. In this study, two recombinant baculoviruses containing the ScathL gene from Sarcophaga peregrina (vSynScathL), and the Keratinase gene from the fungus Aspergillus fumigatus (vSynKerat), were constructed. and their insecticidal properties analysed against Spodoptera frugiperda larvae. Results Bioassays of third-instar and neonate S. frugiperda larvae with vSynScathL and vSynKerat showed a decrease in the time needed to kill the infected insects when compared to the wild type virus. We have also shown that both recombinants were able to increase phenoloxidase activity in the hemolymph of S. frugiperda larvae. The expression of proteases in infected larvae resulted in destruction of internal tissues late in infection, which could be the reason for the increased viral speed of kill. Conclusions Baculoviruses and their recombinant forms constitute viable alternatives to chemical insecticides. Recombinant baculoviruses containing protease genes can be added to the list of engineered baculoviruses with great potential to be used in integrated pest management programs. PMID:20587066

  15. Safety update on the use of recombinant activated factor VII in approved indications.

    Science.gov (United States)

    Neufeld, Ellis J; Négrier, Claude; Arkhammar, Per; Benchikh el Fegoun, Soraya; Simonsen, Mette Duelund; Rosholm, Anders; Seremetis, Stephanie

    2015-06-01

    This updated safety review summarises the large body of safety data available on the use of recombinant activated factor VII (rFVIIa) in approved indications: haemophilia with inhibitors, congenital factor VII (FVII) deficiency, acquired haemophilia and Glanzmann's thrombasthenia. Accumulated data up to 31 December 2013 from clinical trials as well as post-marketing data (registries, literature reports and spontaneous reports) were included. Overall, rFVIIa has shown a consistently favourable safety profile, with no unexpected safety concerns, in all approved indications. No confirmed cases of neutralising antibodies against rFVIIa have been reported in patients with congenital haemophilia, acquired haemophilia or Glanzmann's thrombasthenia. The favourable safety profile of rFVIIa can be attributed to the recombinant nature of rFVIIa and its localised mechanism of action at the site of vascular injury. Recombinant FVIIa activates factor X directly on the surface of activated platelets, which are present only at the site of injury, meaning that systemic activation of coagulation is avoided and the risk of thrombotic events (TEs) thus reduced. Nonetheless, close monitoring for signs and symptoms of TE is warranted in all patients treated with any pro-haemostatic agent, including rFVIIa, especially the elderly and any other patients with concomitant conditions and/or predisposing risk factors to thrombosis. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Immunoadjuvant activities of a recombinant chicken IL-12 in chickens vaccinated with Newcastle disease virus recombinant HN protein.

    Science.gov (United States)

    Su, Bor Sheu; Yin, Hsien Sheng; Chiu, Hua Hsien; Hung, Li Hsiang; Huang, Ji Ping; Shien, Jui Hung; Lee, Long Huw

    2011-08-05

    Recombinant fowlpox virus (rFPV/HN) expressing Newcastle disease virus (NDV) HN gene and rFPV/HN/chIL-12 co-expressing chicken IL-12 (chIL-12) and HN (rHN/chIL-12) genes have been characterized. rHN/chIL-12 or rchIL-12, expressed by our previous construct rFPV/chIL-12, co-administered with rHN was assessed for adjuvant activities of chIL-12. Chickens were vaccinated with various amounts of rHN/chIL-12 mixed with mineral oil (MO), intramuscularly. Levels of hemagglutination-inhibition (HI) antibody production depended on the concentration of the injected rHN or rHN/chIL-12. The lower HI antibody titers were obtained in chicken groups rHN/chIL-12/7-rHN/chIL-12/9, receiving 60ng rHN/8ng chIL-12 with MO, 30ng rHN/4ng chIL-12 with MO or 15ng rHN/2ng chIL-12 with MO, respectively, compared to those in chicken groups rHN/7-rHN/9, receiving rHN with MO alone. However, chickens in group rHN/chIL-12/7 or rHN/chIL-12/8 and rHN with MO alone showed the same effective protection. Chicken group rHN/chIL-12/9 was even more protective than that in group rHN/9. When rchIL-12 was co-injected with 15ng rHN plus MO, chickens produced low levels of HI antibody titers; while higher levels of IFN-γ production and an effective protection rate (83%) were obtained. On the other hand, low levels of IFN-γ production and low protection response (50%) were obtained in chickens injected with rHN with MO alone. Taken together, when the concentration of rHN decreased to certain levels, rchIL-12 reduced HI antibody production. The increase in the induction of IFN-γ production might suggest the enhancement of the cell-mediated immunity which conferred the protection from the NDV challenge. Copyright © 2011 Elsevier B.V. All rights reserved.

  17. Thermal desorption study of physical forces at the PTFE surface

    Science.gov (United States)

    Wheeler, D. R.; Pepper, S. V.

    1987-01-01

    Thermal desorption spectroscopy (TDS) of the polytetrafluoroethylene (PTFE) surface was successfully employed to study the possible role of physical forces in the enhancement of metal-PTFE adhesion by radiation. The thermal desorption spectra were analyzed without assumptions to yield the activation energy for desorption over a range of xenon coverage from less than 0.1 monolayer to more than 100 monolayers. For multilayer coverage, the desorption is zero-order with an activation energy equal to the sublimation energy of xenon. For submonolayer coverages, the order for desorption from the unirradiated PTFE surface is 0.73 and the activation energy for desorption is between 3.32 and 3.36 kcal/mol; less than the xenon sublimation energy. The effect of irradiation is to increase the activation energy for desorption to as high as 4 kcal/mol at low coverage.

  18. Soluble multimer of recombinant endostatin expressed in E. coli has anti-angiogenesis activity

    International Nuclear Information System (INIS)

    Wei Dongmei; Gao Yan; Cao Xiangrong; Zhu Nianchun; Liang Jianfu; Xie Weiping; Zhen Mingying; Zhu Minsheng

    2006-01-01

    The bioactivity, refolding, and multimer formation of endostatin, particularly of recombinant endostatin produced from bacteria, are proved challenging for clinical application. In order to determine the biological activity of recombinant endostatin multimer, first, we expressed endostatin in Escherichia coli and purified it with ion-exchange chromatography. The purified active protein could elicit multimer formation spontaneously, but still has comparable activity. Aim to determine the anti-angiogenic activity of multimer endostatin, by use of RP-HPLC, we then successfully separated endostatin monomer and multimer for subjecting to anti-angiogenesis assay. The results from CAM (chorioallantoic membrane) inhibition assay showed that both monomer and multimer suppressed CAM vascularization significantly. At the dosage of 0.8 μg, inhibition rates of multimeric and monomeric proteins were about 58% and 38%, respectively. Multimeric endostatin exerted a higher activity than monomeric endostatin (p 0.05), although both of them show a high inhibition effect in contrast to control. The results from HUVEC proliferation assay also showed similar effects at dosages of 0.6 and 1.6 μg/ml, multimer exerted a higher activity on inhibition of HUVEC proliferation comparing with monomer (p < 0.05). In conclusion, our results suggest that endostatin multimer has a comparable or higher bioactivity and multimerization will not affect its bioactivity, implying that endostatin activity is insensitive to structure conformation contributed by disulfide bonds

  19. Construction and expression of a recombinant antibody-targeted plasminogen activator

    International Nuclear Information System (INIS)

    Schnee, J.M.; Runge, M.S.; Matsueda, G.A.; Hudson, N.W.; Seidman, J.G.; Haber, E.; Quertermous, T.

    1987-01-01

    Covalent linkage of tissue-type plasminogen activator (t-PA) to a monoclonal antibody specific for the fibrin β chain (anti-fibrin 59D8) results in a thrombolytic agent that is more specific and more potent that t-PA alone. To provide a ready source of this hybrid molecule and to allow tailoring of the active moieties for optimal activity, the authors have engineered a recombinant version of the 59D8-t-PA conjugate. The rearranged 59D8 heavy chain gene was cloned and combined in the expression vector pSV2gpt with sequence coding for a portion of the γ2b constant region and the catalytic β chain of t-PA. This construct was transfected into heavy chain loss variant cells derived form the 59D8 hybridoma. Recombinant protein was purified by affinity chromatography and analyzed with electrophoretic transfer blots and radioimmunoassay. These revealed a 65-kDa heavy chain-t-PA fusion protein that is secreted in association with the 59D8 light chain in the form of a 170-kDa disulfide-linked dimer. Chromogenic substrate assays showed the fusion protein to have 70% of the peptidolytic activity of native t-PA and to activate plasminogen as efficiently as t-PA. IN a competitive binding assay, reconstituted antibody was shown to have a binding profile similar to that of native 59D8. Thus, by recombinant techniques, they have produced a hybrid protein capable of high affinity fibrin binding and plasminogen activation

  20. Catalytic activity of metallic nanoisland coatings. The influence of size effects on the recombination properties

    International Nuclear Information System (INIS)

    Tomilina, O A; Berzhansky, V N; Shaposhnikov, A N; Tomilin, S V

    2016-01-01

    The results of investigations of the quantum-size effects influence on selective properties of heterogeneous nanocatalysts are presents. As etalon exothermic reaction was used the reaction of atomic hydrogen recombination. The nanostructured Pd and Pt films on Teflon substrate were used as a samples of heterogeneous nanocatalysts. It was shown that for nanoparticles with various sizes the catalytic activity has the periodic dependence. It has been found that for certain sizes of nanoparticles their catalytic activity is less than that of Teflon substrate. (paper)

  1. Sensitivity enhancement for nitrophenols using cationic surfactant-modified activated carbon for solid-phase extraction surface-assisted laser desorption/ionization mass spectrometry.

    Science.gov (United States)

    Chen, Y C; Tsai, M F

    2000-01-01

    Previous work has demonstrated that a combination of solid-phase extraction with surface-assisted laser desorption/ionization (SPE-SALDI) mass spectrometry can be applied to the determination of trace nitrophenols in water. An improved method to lower the detection limit of this hyphenated technique is described in this present study. Activated carbon powder is used as both the SPE adsorbent and the SALDI solid in the analysis by SPE-SALDI. The surface of the activated carbon is modified by passing an aqueous solution of a cationic surfactant through the SPE cartridge. The results demonstrate that the sensitivity for nitrophenols in the analysis by SPE-SALDI can be improved by using cationic surfactants to modify the surface of the activated carbon. The detection limit for nitrophenols is about 25 ppt based on a signal-to-noise ratio of 3 by sampling from 100 mL of solution. Copyright 2000 John Wiley & Sons, Ltd.

  2. Cre-dependent DNA recombination activates a STING-dependent innate immune response

    Science.gov (United States)

    Pépin, Geneviève; Ferrand, Jonathan; Höning, Klara; Jayasekara, W. Samantha N.; Cain, Jason E.; Behlke, Mark A.; Gough, Daniel J.; G. Williams, Bryan R.; Hornung, Veit

    2016-01-01

    Abstract Gene-recombinase technologies, such as Cre/loxP-mediated DNA recombination, are important tools in the study of gene function, but have potential side effects due to damaging activity on DNA. Here we show that DNA recombination by Cre instigates a robust antiviral response in mammalian cells, independent of legitimate loxP recombination. This is due to the recruitment of the cytosolic DNA sensor STING, concurrent with Cre-dependent DNA damage and the accumulation of cytoplasmic DNA. Importantly, we establish a direct interplay between this antiviral response and cell–cell interactions, indicating that low cell densities in vitro could be useful to help mitigate these effects of Cre. Taking into account the wide range of interferon stimulated genes that may be induced by the STING pathway, these results have broad implications in fields such as immunology, cancer biology, metabolism and stem cell research. Further, this study sets a precedent in the field of gene-engineering, possibly applicable to other enzymatic-based genome editing technologies. PMID:27166376

  3. Refolding Techniques for Recovering Biologically Active Recombinant Proteins from Inclusion Bodies

    Directory of Open Access Journals (Sweden)

    Hiroshi Yamaguchi

    2014-02-01

    Full Text Available Biologically active proteins are useful for studying the biological functions of genes and for the development of therapeutic drugs and biomaterials in a biotechnology industry. Overexpression of recombinant proteins in bacteria, such as Escherichia coli, often results in the formation of inclusion bodies, which are protein aggregates with non-native conformations. As inclusion bodies contain relatively pure and intact proteins, protein refolding is an important process to obtain active recombinant proteins from inclusion bodies. However, conventional refolding methods, such as dialysis and dilution, are time consuming and, often, recovered yields of active proteins are low, and a trial-and-error process is required to achieve success. Recently, several approaches have been reported to refold these aggregated proteins into an active form. The strategies largely aim at reducing protein aggregation during the refolding procedure. This review focuses on protein refolding techniques using chemical additives and laminar flow in microfluidic chips for the efficient recovery of active proteins from inclusion bodies.

  4. Top3 processes recombination intermediates and modulates checkpoint activity after DNA damage

    DEFF Research Database (Denmark)

    Mankouri, Hocine W; Hickson, Ian D

    2006-01-01

    Mutation of TOP3 in Saccharomyces cerevisiae causes poor growth, hyperrecombination, and a failure to fully activate DNA damage checkpoints in S phase. Here, we report that overexpression of a dominant-negative allele of TOP3, TOP3(Y356F), which lacks the catalytic (decatenation) activity of Top3......, the catalytic activity of Top3 is not required for DNA damage checkpoint activation, but it is required for normal S-phase progression after DNA damage. We also present evidence that the checkpoint-mediated cell cycle delay and persistence of X-shaped DNA molecules resulting from overexpression of TOP3(Y356F......) are downstream of Rad51 function. We propose that Top3 functions in S phase to both process homologous recombination intermediates and modulate checkpoint activity....

  5. Reversible Second Order Kinetics of Sorption-Desorption of Cr(VI Ion on Activated Carbon from Palm Empty Fruit Bunches

    Directory of Open Access Journals (Sweden)

    Iip Izul Falah

    2015-11-01

    Full Text Available Activated carbon (AC from palm empty fruit bunches has been prepared, and this material was then used to adsorb Cr(VI from a solution. Characterization of the AC was conducted by detection of its functional groups, determination of total volatile compounds (VC content and its iodine number. Study on sorption-desorption kinetics was conducted by comparing results of evaluations of several models with proposed reversible second order model using the data produced in this work. Results of the works showed that the AC had similar characters compared with the AC produced by previous researchers. Application of the kinetics models on sorption Cr(VI onto the AC showed that nearly all of the models gave a good linearity. However, only the proposed model had a good relation with Langmuir isotherm, with respectively sorption (ks and desorption (kd constants were 5.75 x 10-4 L.mg‑1.min-1 and 2.20 x 10-3 min-1; maximum sorption capacity, qm = 20.00 mg.g-1; and equilibrium constant, K from kinetics experiment (0.261 L.mg-1 was comparable with the result from the isotherm experiment (0.269 L.mg-1. Hence, using this model, kinetics and Langmuir parameters can probably be determined from a single kinetics data experiment.

  6. Biological activity analysis of native and recombinant streptokinase using clot lysis and chromogenic substrate assay.

    Science.gov (United States)

    Mahboubi, Arash; Sadjady, Seyyed Kazem; Mirzaei Saleh Abadi, Mohammad; Azadi, Saeed; Solaimanian, Roya

    2012-01-01

    DETERMINATION OF STREPTOKINASE ACTIVITY IS USUALLY ACCOMPLISHED THROUGH TWO ASSAY METHODS: a) Clot lysis, b) Chromogenic substrate assay. In this study the biological activity of two streptokinase products, namely Streptase®, which is a native product and Heberkinasa®, which is a recombinant product, was determined against the third international reference standard using the two forementioned assay methods. The results indicated that whilst the activity of Streptase® was found to be 101 ± 4% and 97 ± 5% of the label claim with Clot lysis and Chromogenic substrate assay respectively, for Heberkinasa® the potency values obtained were 42 ± 5% and 92.5 ± 2% of the label claim respectively. To shed some light on the reason for this finding, the n-terminal sequence of the streptokinase molecules present in the two products was determined. The results showed slight differences in the amino acid sequence of the recombinant product in comparison to the native one at the amino terminus. This finding supports those of other workers who found that n-terminal sequence of the streptokinase molecule can have significant effect on the activity of this protein.

  7. Active site electrostatics protect genome integrity by blocking abortive hydrolysis during DNA recombination

    Science.gov (United States)

    Ma, Chien-Hui; Rowley, Paul A; Macieszak, Anna; Guga, Piotr; Jayaram, Makkuni

    2009-01-01

    Water, acting as a rogue nucleophile, can disrupt transesterification steps of important phosphoryl transfer reactions in DNA and RNA. We have unveiled this risk, and identified safeguards instituted against it, during strand cleavage and joining by the tyrosine site-specific recombinase Flp. Strand joining is threatened by a latent Flp endonuclease activity (type I) towards the 3′-phosphotyrosyl intermediate resulting from strand cleavage. This risk is not alleviated by phosphate electrostatics; neutralizing the negative charge on the scissile phosphate through methylphosphonate (MeP) substitution does not stimulate type I endonuclease. Rather, protection derives from the architecture of the recombination synapse and conformational dynamics within it. Strand cleavage is protected against water by active site electrostatics. Replacement of the catalytic Arg-308 of Flp by alanine, along with MeP substitution, elicits a second Flp endonuclease activity (type II) that directly targets the scissile phosphodiester bond in DNA. MeP substitution, combined with appropriate active site mutations, will be useful in revealing anti-hydrolytic mechanisms engendered by systems that mediate DNA relaxation, DNA transposition, site-specific recombination, telomere resolution, RNA splicing and retrohoming of mobile introns. PMID:19440204

  8. The Meiotic Recombination Activator PRDM9 Trimethylates Both H3K36 and H3K4 at Recombination Hotspots In Vivo.

    Science.gov (United States)

    Powers, Natalie R; Parvanov, Emil D; Baker, Christopher L; Walker, Michael; Petkov, Petko M; Paigen, Kenneth

    2016-06-01

    In many mammals, including humans and mice, the zinc finger histone methyltransferase PRDM9 performs the first step in meiotic recombination by specifying the locations of hotspots, the sites of genetic recombination. PRDM9 binds to DNA at hotspots through its zinc finger domain and activates recombination by trimethylating histone H3K4 on adjacent nucleosomes through its PR/SET domain. Recently, the isolated PR/SET domain of PRDM9 was shown capable of also trimethylating H3K36 in vitro, raising the question of whether this reaction occurs in vivo during meiosis, and if so, what its function might be. Here, we show that full-length PRDM9 does trimethylate H3K36 in vivo in mouse spermatocytes. Levels of H3K4me3 and H3K36me3 are highly correlated at hotspots, but mutually exclusive elsewhere. In vitro, we find that although PRDM9 trimethylates H3K36 much more slowly than it does H3K4, PRDM9 is capable of placing both marks on the same histone molecules. In accord with these results, we also show that PRDM9 can trimethylate both K4 and K36 on the same nucleosomes in vivo, but the ratio of K4me3/K36me3 is much higher for the pair of nucleosomes adjacent to the PRDM9 binding site compared to the next pair further away. Importantly, H3K4me3/H3K36me3-double-positive nucleosomes occur only in regions of recombination: hotspots and the pseudoautosomal (PAR) region of the sex chromosomes. These double-positive nucleosomes are dramatically reduced when PRDM9 is absent, showing that this signature is PRDM9-dependent at hotspots; the residual double-positive nucleosomes most likely come from the PRDM9-independent PAR. These results, together with the fact that PRDM9 is the only known mammalian histone methyltransferase with both H3K4 and H3K36 trimethylation activity, suggest that trimethylation of H3K36 plays an important role in the recombination process. Given the known requirement of H3K36me3 for double strand break repair by homologous recombination in somatic cells, we

  9. Does intravenous administration of recombinant tissue plasminogen activator for ischemic stroke can cause inferior myocardial infarction?

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    Mostafa Almasi

    2016-06-01

    Full Text Available Recombinant tissue plasminogen activator (rTPA is one of the main portions of acute ischemic stroke management, but unfortunately has some complications. Myocardial infarction (MI is a hazardous complication of administration of intravenous rTPA that has been reported recently. A 78-year-old lady was admitted for elective coronary artery bypass graft surgery. On the second day of admission, she developed acute left hemiparesis and intravenous rTPA was administered within 120 minutes. Three hours later, she has had chest pain. Rescue percutaneous coronary intervention was performed on right coronary artery due to diagnosis of inferior MI, and the symptoms were resolved.

  10. Production and characterization of guinea pig recombinant gamma interferon and its effect on macrophage activation.

    Science.gov (United States)

    Jeevan, A; McFarland, C T; Yoshimura, T; Skwor, T; Cho, H; Lasco, T; McMurray, D N

    2006-01-01

    Gamma interferon (IFN-gamma) plays a critical role in the protective immune responses against mycobacteria. We previously cloned a cDNA coding for guinea pig IFN-gamma (gpIFN-gamma) and reported that BCG vaccination induced a significant increase in the IFN-gamma mRNA expression in guinea pig cells in response to living mycobacteria and that the virulent H37Rv strain of Mycobacterium tuberculosis stimulated less IFN-gamma mRNA than did the attenuated H37Ra strain. In this study, we successfully expressed and characterized recombinant gpIFN-gamma with a histidine tag at the N terminus (His-tagged rgpIFN-gamma) in Escherichia coli. rgpIFN-gamma was identified as an 18-kDa band in the insoluble fraction; therefore, the protein was purified under denaturing conditions and renatured. N-terminal amino acid sequencing of the recombinant protein yielded the sequence corresponding to the N terminus of His-tagged gpIFN-gamma. The recombinant protein upregulated major histocompatibility complex class II expression in peritoneal macrophages. The antiviral activity of rgpIFN-gamma was demonstrated with a guinea pig fibroblast cell line (104C1) infected with encephalomyocarditis virus. Interestingly, peritoneal macrophages treated with rgpIFN-gamma did not produce any nitric oxide but did produce hydrogen peroxide and suppressed the intracellular growth of mycobacteria. Furthermore, rgpIFN-gamma induced morphological alterations in cultured macrophages. Thus, biologically active rgpIFN-gamma has been successfully produced and characterized in our laboratory. The study of rgpIFN-gamma will further increase our understanding of the cellular and molecular responses induced by BCG vaccination in the guinea pig model of pulmonary tuberculosis.

  11. Technetium-99m-labeled recombinant tissue plasminogen activator for the imaging of emboli in vivo

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Akihiro; Itoh, Kazuo; Tsukamoto, Eriko; Furudate, Masayori; Kamiyama, Hiroyasu; Abe, Hiroshi [Hokkaido Univ., Sapporo (Japan). School of Medicine

    1993-07-01

    Tissue-type plasminogen activator (t-PA) effectively lyses activate thrombus by direct action. Recombinant t-PA (rt-PA) was labeled with technetium-99m ([sup 99m]Tc) to investigate the in vivo binding to fibrin clots in a feline cerebral embolism model created by insertion of an artificial fibrin clot within the carotid artery. [sup 99m]Tc-rt-PA administered intravenously provided clearer imaging of clots after priming with cold rt-PA, with uptake peaking 5-10 minutes after the injection. [sup 99m]Tc-labeled human serum albumin was not retained at clot sites. Systemically administered [sup 99m]Tc-rt-PA binds to fibrin clots within carotid arteries in our feline model. Our results suggest that the interaction of intrinsic plasminogen activator inhibitors with extrinsically administered rt-PA may regulate the demonstration of a clot, although the precise mechanism is unclear. (author).

  12. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

    Science.gov (United States)

    Dolinska, Monika B; Kovaleva, Elena; Backlund, Peter; Wingfield, Paul T; Brooks, Brian P; Sergeev, Yuri V

    2014-01-01

    Tyrosinase (TYR) catalyzes the rate-limiting, first step in melanin production and its gene (TYR) is mutated in many cases of oculocutaneous albinism (OCA1), an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes. The intra-melanosomal domain of human tyrosinase (residues 19-469) and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure. The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

  13. Albinism-causing mutations in recombinant human tyrosinase alter intrinsic enzymatic activity.

    Directory of Open Access Journals (Sweden)

    Monika B Dolinska

    Full Text Available Tyrosinase (TYR catalyzes the rate-limiting, first step in melanin production and its gene (TYR is mutated in many cases of oculocutaneous albinism (OCA1, an autosomal recessive cause of childhood blindness. Patients with reduced TYR activity are classified as OCA1B; some OCA1B mutations are temperature-sensitive. Therapeutic research for OCA1 has been hampered, in part, by the absence of purified, active, recombinant wild-type and mutant human enzymes.The intra-melanosomal domain of human tyrosinase (residues 19-469 and two OCA1B related temperature-sensitive mutants, R422Q and R422W were expressed in insect cells and produced in T. ni larvae. The short trans-membrane fragment was deleted to avoid potential protein insolubility, while preserving all other functional features of the enzymes. Purified tyrosinase was obtained with a yield of >1 mg per 10 g of larval biomass. The protein was a monomeric glycoenzyme with maximum enzyme activity at 37°C and neutral pH. The two purified mutants when compared to the wild-type protein were less active and temperature sensitive. These differences are associated with conformational perturbations in secondary structure.The intramelanosomal domains of recombinant wild-type and mutant human tyrosinases are soluble monomeric glycoproteins with activities which mirror their in vivo function. This advance allows for the structure - function analyses of different mutant TYR proteins and correlation with their corresponding human phenotypes; it also provides an important tool to discover drugs that may improve tyrosinase activity and treat OCA1.

  14. Recombinant-activated factor VII in patients with uncontrolled bleeding: A retrospective observational analysis

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    Said D Abuhasna

    2012-01-01

    Full Text Available Background: Factor VIIa (recombinant has an off-label use to control life-threatening bleeding that is refractory to other measures and was shown to decrease transfusion requirements. Objective: The primary objective of this study was to assess the safety and effectiveness of factor VIIa (recombinant on blood transfusion requirements and coagulation parameters when used in patients whose bleeding was uncorrected by other means. The pharmacoeconomic impact for any discrepancy from our protocol was evaluated. Secondary outcomes included 4-hour and 28-day mortality, as well as safety of this agent in terms of thromboembolic complications. Materials and Methods: We retrospectively evaluated patients who received recombinant-activated factor VII (rFVIIa for uncontrolled bleeding from June 2008 to April 2011. The medical records of 33 patients were evaluated. Coagulation parameters and blood products were determined 24 hours before and 24 hours after administration of rFVIIa, and the results compared. Patients were also screened for any thromboembolic complications. Results: Administration of rFVIIa reduced blood transfusion requirements and improved coagulation parameters significantly (P<0.05. No thromboembolic complications were reported. Most of the dosing was consistent with those recommended in our institutional protocol, with discrepancies resulting in an average cost of $56 058. Moreover, pH was reported in only 67% of patients. All patients treated with rFVIIa survived up to 4 hours after receiving this agent, while the 28-day mortality was 24% (8/33. Conclusion: The use of rFVIIa appears to be safe and effective in promoting hemostasis, as evident from reducing transfusion requirements and improving the coagulation variables.

  15. Construction and Antiapoptosis Activities of Recombinant Adenoviral Expression Vector Carrying EBV Latent Membrane Protein 2A

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    Xishuang Liu

    2011-01-01

    Full Text Available To evaluate the possible effects of LMP2A (EBV latent membrane protein 2A on human gastric cancer cell line SGC-7901, LMP2A coding gene was subcloned into shuttle plasmid pAdTrackCMV to form transfer plasmid pAdTrackCMV-2A, which was linearized with PmeI and cotransformed into E.coli BJ5183 with adenovirus genomic plasmid of pAdeasy-1. The identified recombinant adenovirus plasmid DNA was digested with PacI and transfected into 293 cells to package recombinant adenovirus particles named vAd-2A. Then the expression and antiapoptosis activities of LMP2A on SGC-7901 infected with vAd-2A were analyzed. The vAd-2A was successfully constructed and identified by PCR, restriction digestion, and sequencing. LMP2A expression in SGC was identified by strong green fluorescence expression with fluorescence microscopic photograph and Southern blotting. The growth of LMP2A expressing SGC cells was apparently improved. Both cyclin E expression and S phase ratio in LMP2A expressing SGC cells were upregulated by cell cycle analysis and confocal microscopic analysis respectively. The replication-deficient recombinant adenovirus vector can express LMP2A antigen in SGC cells and inhibit their apoptosis. The results indicate that LMP2A might play an important role in pathogenesis of EBV-associated gastric cancer (EBVaGC. This study establishes a foundation for further study on EBVaGC and its gene therapy.

  16. Biologic activities of recombinant human-beta-defensin-4 toward cultured human cancer cells.

    Science.gov (United States)

    Gerashchenko, O L; Zhuravel, E V; Skachkova, O V; Khranovska, N N; Filonenko, V V; Pogrebnoy, P V; Soldatkina, M A

    2013-06-01

    The aim of the study was in vitro analysis of biological activity of recombinant human beta-defensin-4 (rec-hBD-4). hBD-4 cDNA was cloned into pGEX-2T vector, and recombinant plasmid was transformed into E. coli BL21(DE3) cells. To purify soluble fusion GST-hBD-4 protein, affinity chromatography was applied. Rec-hBD-4 was cleaved from the fusion protein with thrombin, and purified by reverse phase chromatography on Sep-Pack C18. Effects of rec-hBD-4 on proliferation, viability, cell cycle distribution, substrate-independent growth, and mobility of cultured human cancer cells of A431, A549, and TPC-1 lines were analyzed by direct cell counting technique, MTT assay, flow cytofluorometry, colony forming assay in semi-soft medium, and wound healing assay. Rec-hBD-4 was expressed in bacterial cells as GST-hBD-4 fusion protein, and purified by routine 3-step procedure (affine chromatography on glutathione-agarose, cleavage of fusion protein by thrombin, and reverse phase chromatography). Analysis of in vitro activity of rec-hBD-4 toward three human cancer cell lines has demonstrated that the defensin is capable to affect cell behaviour in concentration-dependent manner. In 1-100 nM concentrations rec-hBD-4 significantly stimulates cancer cell proliferation and viability, and promotes cell cycle progression through G2/M checkpoint, greatly enhances colony-forming activity and mobility of the cells. Treatment of the cells with 500 nM of rec-hBD-4 resulted in opposite effects: significant suppression of cell proliferation and viability, blockage of cell cycle in G1/S checkpoint, significant inhibition of cell migration and colony forming activity. Recombinant human beta-defensin-4 is biologically active peptide capable to cause oppositely directed effects toward biologic features of cancer cells in vitro dependent on its concentration.

  17. Evaluation of Aryoseven Safety (Recombinant Activated Factor VII) in Patients with Bleeding Disorders (An Observational Post-Marketing Surveillance Study).

    Science.gov (United States)

    Toogeh, Gholamreza; Abolghasemi, Hassan; Eshghi, Peyman; Managhchi, Mohammadreza; Shaverdi-Niasari, Mohammadreza; Karimi, Katayoon; Roostaei, Samin; Emran, Neda; Abdollahi, Alireza

    2016-01-01

    Recombinant activated factor VII induces hemostasis in patients with coagulopathy disorders. AryoSeven™ as a safe Iranian Recombinant activated factor VII has been available on our market. This study was performed to establish the safety of AryoSeven on patients with coagulopathy disorder. This single-center, descriptive, cross sectional study was carried out in Thrombus and Homeostasis Research Center ValiAsr Hospital during 2013-2014. Fifty one patients with bleeding disorders who received at least one dose of Aryoseven were enrolled. Patients' demographic data and adverse effect of drug and reaction related to Aryoseven or previous usage of Recombinant activated FVII were recorded in questionnaires. Finally data were analyzed to compare side effects of Aryoseven and other Recombinant activated FVII brands. Aryoseven was prescribed for 51 Patients. Of all participants with mean age 57.18+21.38 yr, 31 cases were male and 26 subjects had past history of recombinant activated FVII usage. Glanzman was the most frequent disorder followed by congenital FVII deficiency, hemophilia with inhibitors, factor 5 deficiency, acquired hemophilia, hemophilia A with inhibitor, and hemophilia A or B with inhibitor. The majority of bleeding episodes had occurred in joints. Three patients (5.9%) complained about adverse effects of Aryoseven vs. 11.5 % about adverse effects of other brands. However this difference was not significant, statistically. Based on monitor patients closely for any adverse events, we concluded that Aryoseven administration under careful weighing of benefit versus potential harm may comparable with other counterpart drugs.

  18. Correlation between the glycan variations and defibrinogenating activities of acutobin and its recombinant glycoforms.

    Directory of Open Access Journals (Sweden)

    Ying-Ming Wang

    Full Text Available Acutobin isolated from Deinagkistrodon acutus venom has been used to prevent or treat stroke in patients. This defibrinogenating serine protease is a 39 kDa glycoprotein containing terminal disialyl-capped N-glycans. After sialidase treatment, the enzyme showed similar catalytic activities toward chromogenic substrate, and cleaved the Aα chain of fibrinogen as efficiently as the native acutobin did. However, the level of fibrinogen degradation products in mice after i.p.-injection of desialylated-acutobin was significantly lower than the level after acutobin injection, suggesting that the disialyl moieties may improve or prolong the half-life of acutobin. Two recombinant enzymes with identical protein structures and similar amidolytic activities to those of native acutobin were expressed from HEK293T and SW1353 cells and designated as HKATB and SWATB, respectively. Mass spectrometric profiling showed that their glycans differed from those of acutobin. In contrast to acutobin, HKATB cleaved not only the Aα chain but also the Bβ and γ chains of human fibrinogens, while SWATB showed a reduced α-fibrinogenase activity. Non-denaturing deglycosylation of these proteases by peptide N-glycosidase F significantly reduced their fibrinogenolytic activities and thermal stabilities. The in vivo defibrinogenating effect of HKATB was inferior to that of acutobin in mice. Taken together, our results suggest that the conjugated glycans of acutobin are involved in its interaction with fibrinogen, and that the selection of cells optimally expressing efficient glycoforms and further glycosylation engineering are desirable before a recombinant product can replace the native enzyme for clinical use.

  19. Chromate-reducing activity of Hansenula polymorpha recombinant cells over-producing flavocytochrome b₂.

    Science.gov (United States)

    Smutok, Oleh; Broda, Daniel; Smutok, Halyna; Dmytruk, Kostyantyn; Gonchar, Mykhailo

    2011-04-01

    In spite of the great interest to studies of the biological roles of chromium, as well as the toxic influence of Cr(VI)-species on living organisms, the molecular mechanisms of chromate bioremediation remain vague. A reductive pathway resulting in formation of less toxic Cr(III)-species is suggested to be the most important among possible mechanisms for chromate biodetoxification. The yeast l-lactate:cytochrome c-oxidoreductase (flavocytochrome b(2), FC b(2)) has absolute specificity for l-lactate, yet is non-selective with respect to its electron acceptor. These properties allow us to consider the enzyme as a potential candidate for chromate reduction by living cells in the presence of l-lactate. A recombinant strain of thermotolerant, methylotrophic yeast Hansenula polymorpha with sixfold increased FC b(2) enzyme activity (up to 3μmolmin(-1)mg(-1) protein in cell-free extract) compared to the parental strain was used for approval our suggestion. The recombinant cells, stored in dried state, as well as living yeast cells were tested for chromate-reducing activity in vitro in the presence of l-lactate (as an electron donor for chromate reduction) and different low molecular weight, redox-active mediators facilitating electron transfer from the reduced form of the enzyme to chromate (as a final electron acceptor): dichlorophenolindophenol (DCPIP), Methylene blue, Meldola blue, and Nile blue. It was shown that the highest chromate-reducing activity of the cells was achieved in the presence of DCPIP. The ability of chromate to catch electrons from the reduced flavocytochrome b(2) was confirmed using purified enzyme immobilized on the surface of a platinum electrode. The increasing concentration of Cr(VI) resulted in a decrease of enzyme-mediated current generated on the electrode during l-lactate oxidation. The shift and drop in amplitude of the peak in the cyclic voltammogram are indicative of Cr(VI)-dependent competition between reaction of chromate with reduced FC

  20. Perlecan domain 1 recombinant proteoglycan augments BMP-2 activity and osteogenesis

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    DeCarlo Arthur A

    2012-09-01

    Full Text Available Abstract Background Many growth factors, such as bone morphogenetic protein (BMP-2, have been shown to interact with polymers of sulfated disacharrides known as heparan sulfate (HS glycosaminoglycans (GAGs, which are found on matrix and cell-surface proteoglycans throughout the body. HS GAGs, and some more highly sulfated forms of chondroitin sulfate (CS, regulate cell function by serving as co-factors, or co-receptors, in GF interactions with their receptors, and HS or CS GAGs have been shown to be necessary for inducing signaling and GF activity, even in the osteogenic lineage. Unlike recombinant proteins, however, HS and CS GAGs are quite heterogenous due, in large part, to post-translational addition, then removal, of sulfate groups to various positions along the GAG polymer. We have, therefore, investigated whether it would be feasible to deliver a DNA pro-drug to generate a soluble HS/CS proteoglycan in situ that would augment the activity of growth-factors, including BMP-2, in vivo. Results Utilizing a purified recombinant human perlecan domain 1 (rhPln.D1 expressed from HEK 293 cells with HS and CS GAGs, tight binding and dose-enhancement of rhBMP-2 activity was demonstrated in vitro. In vitro, the expressed rhPln.D1 was characterized by modification with sulfated HS and CS GAGs. Dose-enhancement of rhBMP-2 by a pln.D1 expression plasmid delivered together as a lyophilized single-phase on a particulate tricalcium phosphate scaffold for 6 or more weeks generated up to 9 fold more bone volume de novo on the maxillary ridge in a rat model than in control sites without the pln.D1 plasmid. Using a significantly lower BMP-2 dose, this combination provided more than 5 times as much maxillary ridge augmentation and greater density than rhBMP-2 delivered on a collagen sponge (InFuse™. Conclusions A recombinant HS/CS PG interacted strongly and functionally with BMP-2 in binding and cell-based assays, and, in vivo, the pln.247 expression plasmid

  1. White shrimp (Litopenaeus vannamei) recombinant lysozyme has antibacterial activity against Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae.

    Science.gov (United States)

    de-la-Re-Vega, Enrique; García-Galaz, Alfonso; Díaz-Cinco, Martha E; Sotelo-Mundo, Rogerio R

    2006-03-01

    C-type lysozyme has been described as an antibacterial component of the shrimp innate defence system. We determined quantitatively the antibacterial activity of white shrimp (Litopenaeus vannamei) recombinant lysozyme against three Gram negative bacteria: Vibrio alginolyticus, Vibrio parahemolyticus and Vibrio cholerae, using a turbidimetric assay with live bacteria and differential bacterial viable count after interaction with the protein. In conclusion, the antibacterial activity of recombinant shrimp lysozyme against Vibrio sp. is at least equal to the values against the Gram positive M. luteus and more active against the shrimp pathogens V. alginolyticus and V. parahemolyticus.

  2. Residual endotoxin contaminations in recombinant proteins are sufficient to activate human CD1c+ dendritic cells.

    Directory of Open Access Journals (Sweden)

    Harald Schwarz

    Full Text Available Many commercially available recombinant proteins are produced in Escherichia coli, and most suppliers guarantee contamination levels of less than 1 endotoxin unit (EU. When we analysed commercially available proteins for their endotoxin content, we found contamination levels in the same range as generally stated in the data sheets, but also some that were higher. To analyse whether these low levels of contamination have an effect on immune cells, we stimulated the monocytic cell line THP-1, primary human monocytes, in vitro differentiated human monocyte-derived dendritic cells, and primary human CD1c+ dendritic cells (DCs with very low concentrations of lipopolysaccharide (LPS; ranging from 0.002-2 ng/ml. We show that CD1c+ DCs especially can be activated by minimal amounts of LPS, equivalent to the levels of endotoxin contamination we detected in some commercially available proteins. Notably, the enhanced endotoxin sensitivity of CD1c+ DCs was closely correlated with high CD14 expression levels observed in CD1c+ DCs that had been maintained in cell culture medium for 24 hours. When working with cells that are particularly sensitive to LPS, even low endotoxin contamination may generate erroneous data. We therefore recommend that recombinant proteins be thoroughly screened for endotoxin contamination using the limulus amebocyte lysate test, fluorescence-based assays, or a luciferase based NF-κB reporter assay involving highly LPS-sensitive cells overexpressing TLR4, MD-2 and CD14.

  3. Antibacterial activity and phospholipid recognition of the recombinant defensin J1-1 from Capsicum genus.

    Science.gov (United States)

    Guillén-Chable, Francisco; Arenas-Sosa, Iván; Islas-Flores, Ignacio; Corzo, Gerardo; Martinez-Liu, Cynthia; Estrada, Georgina

    2017-08-01

    The gene of the four disulfide-bridged defensin J1-1 from Capsicum was cloned into the expression vector pQE30 containing a 6His-tag as fusion protein. This construct was transfected into Origami strain of Escherichia coli and expressed after induction with isopropyl thiogalactoside (IPTG). The level of expression was 4 mg/L of culture medium, and the His-tagged recombinant defensin (HisXarJ1-1) was expressed exclusively into inclusion bodies. After solubilization, HisXarJ1-1 was purified by affinity and hydrophobic interaction chromatography. The reverse-phase HPLC profile of the HisXarJ1-1 product obtained from the affinity chromatography step showed single main peptide fraction of molecular masses of 7050.6 Da and after treatment with DTT a single fraction of 7, 042.6 Da corresponding to the reduced peptide was observed. An in vitro folding step of the HisXarJ1-1 generated a distinct profile of oxidized forms of the peptide this oxidized peptide was capable of binding phosphatidic acid in vitro. Possible dimer and oligomer of HisXarJ1-1 were visible in gel electrophoresis and immunodetected with anti-His antibodies. Pure recombinant defensin HisXarJ1-1 exhibited antibacterial activity against Pseudomonas aeruginosa. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Measurement of laser activated electron tunneling from semiconductor zinc oxide to adsorbed organic molecules by a matrix assisted laser desorption ionization mass spectrometer

    International Nuclear Information System (INIS)

    Zhong Hongying; Fu Jieying; Wang Xiaoli; Zheng Shi

    2012-01-01

    Highlights: ► Irradiation of photons with energies more than the band gap generates electron–hole pairs. ► Electron tunneling probability is dependent on the electron mobility. ► Tunneling electrons are captured by charge deficient atoms. ► Unpaired electrons induce cleavages of chemical bonds. - Abstract: Measurement of light induced heterogeneous electron transfer is important for understanding of fundamental processes involved in chemistry, physics and biology, which is still challenging by current techniques. Laser activated electron tunneling (LAET) from semiconductor metal oxides was observed and characterized by a MALDI (matrix assisted laser desorption ionization) mass spectrometer in this work. Nanoparticles of ZnO were placed on a MALDI sample plate. Free fatty acids and derivatives were used as models of organic compounds and directly deposited on the surface of ZnO nanoparticles. Irradiation of UV laser (λ = 355 nm) with energy more than the band gap of ZnO produces ions that can be detected in negative mode. When TiO 2 nanoparticles with similar band gap but much lower electron mobility were used, these ions were not observed unless the voltage on the sample plate was increased. The experimental results indicate that laser induced electron tunneling is dependent on the electron mobility and the strength of the electric field. Capture of low energy electrons by charge-deficient atoms of adsorbed organic molecules causes unpaired electron-directed cleavages of chemical bonds in a nonergodic pathway. In positive detection mode, electron tunneling cannot be observed due to the reverse moving direction of electrons. It should be able to expect that laser desorption ionization mass spectrometry is a new technique capable of probing the dynamics of electron tunneling. LAET offers advantages as a new ionization dissociation method for mass spectrometry.

  5. Protein-only, antimicrobial peptide-containing recombinant nanoparticles with inherent built-in antibacterial activity.

    Science.gov (United States)

    Serna, Naroa; Sánchez-García, Laura; Sánchez-Chardi, Alejandro; Unzueta, Ugutz; Roldán, Mónica; Mangues, Ramón; Vázquez, Esther; Villaverde, Antonio

    2017-09-15

    The emergence of bacterial antibiotic resistances is a serious concern in human and animal health. In this context, naturally occurring cationic antimicrobial peptides (AMPs) might play a main role in a next generation of drugs against bacterial infections. Taking an innovative approach to design self-organizing functional proteins, we have generated here protein-only nanoparticles with intrinsic AMP microbicide activity. Using a recombinant version of the GWH1 antimicrobial peptide as building block, these materials show a wide antibacterial activity spectrum in absence of detectable toxicity on mammalian cells. The GWH1-based nanoparticles combine clinically appealing properties of nanoscale materials with full biocompatibility, structural and functional plasticity and biological efficacy exhibited by proteins. Because of the largely implemented biological fabrication of recombinant protein drugs, the protein-based platform presented here represents a novel and scalable strategy in antimicrobial drug design, that by solving some of the limitations of AMPs offers a promising alternative to conventional antibiotics. The low molecular weight antimicrobial peptide GWH1 has been engineered to oligomerize as self-assembling protein-only nanoparticles of around 50nm. In this form, the peptide exhibits potent and broad antibacterial activities against both Gram-positive and Gram-negative bacteria, without any harmful effect over mammalian cells. As a solid proof-of-concept, this finding strongly supports the design and biofabrication of nanoscale antimicrobial materials with in-built functionalities. The protein-based homogeneous composition offer advantages over alternative materials explored as antimicrobial agents, regarding biocompatibility, biodegradability and environmental suitability. Beyond the described prototype, this transversal engineering concept has wide applicability in the design of novel nanomedicines for advanced treatments of bacterial infections

  6. Ligand-receptor assay for evaluation of functional activity of human recombinant VEGF and VEGFR-1 extracellular fragment.

    Science.gov (United States)

    Leopol'd, A V; Baklaushev, V P; Korchagina, A A; Shein, S A; Grinenko, N F; Pavlov, K A; Ryabukhin, I A; Chekhonin, V P

    2012-04-01

    cDNA encoding VEGF and Ig-like extracellular domains 2-4 of VEGFR-1 (sFlt-1(2-4)) were cloned into prokaryotic expression vectors pET32a and pQE60. Recombinant proteins were purified (metal affinity chromatography) and renatured. Chemiluminescent study for the interaction of recombinant VEGF and sFlt-1(2-4) showed that biotinylated VEGF specifically binds to the polystyrene-immobilized receptor extracellular fragment. Biotinylated recombinant sFlt-1 interacts with immobilized VEGF. Analysis of the interaction of immobilized recombinant VEGFR-1 and VEGF with C6 glioma cells labeled with CFDA-SE (vital fluorescent dye) showed that recombinant VEGFR-1 also binds to native membrane-associated VEGF. Recombinant VEGF was shown to bind to specific receptors expressed on the surface of C6 glioma cells. Functional activity of these proteins was confirmed by ligand-receptor assay for VEGF and VEGFR-1 (sFlt-1) and quantitative chemiluminescent detection.

  7. Adsorption isotherms, kinetics, thermodynamics and desorption studies of 2,4,6-trichlorophenol on oil palm empty fruit bunch-based activated carbon

    International Nuclear Information System (INIS)

    Tan, I.A.W.; Ahmad, A.L.; Hameed, B.H.

    2009-01-01

    The adsorption characteristics of 2,4,6-trichlorophenol (TCP) on activated carbon prepared from oil palm empty fruit bunch (EFB) were evaluated. The effects of TCP initial concentration, agitation time, solution pH and temperature on TCP adsorption were investigated. TCP adsorption uptake was found to increase with increase in initial concentration, agitation time and solution temperature whereas adsorption of TCP was more favourable at acidic pH. The adsorption equilibrium data were best represented by the Freundlich and Redlich-Peterson isotherms. The adsorption kinetics was found to follow the pseudo-second-order kinetic model. The mechanism of the adsorption process was determined from the intraparticle diffusion model. Boyd plot revealed that the adsorption of TCP on the activated carbon was mainly governed by particle diffusion. Thermodynamic parameters such as standard enthalpy (ΔH o ), standard entropy (ΔS o ), standard free energy (ΔG o ) and activation energy were determined. The regeneration efficiency of the spent activated carbon was high, with TCP desorption of 99.6%.

  8. Universal scaling for biomolecule desorption induced by swift heavy ions

    International Nuclear Information System (INIS)

    Szenes, G.

    2005-01-01

    A thermal activation mechanism is proposed for the desorption of biomolecules. Good agreement is found with the experiments in a broad range of the electronic stopping power. The activation energies of desorption U are 0.33, 1.57 and 5.35 eV for positive, negative and neutral leucine molecules, respectively, and 2.05 eV for positive ergosterol molecules. The desorption of valine clusters is analyzed. The magnitude of the specific heat shows that the internal degrees of freedom are not excited up to the moment of desorption. The effect of irradiation temperature and of ion velocity on the desorption yield is discussed on the basis of the author's model. The scaling function derived in the model for the desorption of biomolecules is applied also to the sputtering of SiO 2 and U = 0.42 eV is obtained

  9. Presence of the propeptide on recombinant lysosomal dipeptidase controls both activation and dimerization.

    Science.gov (United States)

    Dolenc, Iztok; Pain, Roger; Turk, Vito

    2007-01-01

    Lysosomal dipeptidase catalyzes the hydrolysis of dipeptides with unsubstituted terminals. It is a homodimer and binds zinc. Dimerization is an important issue in understanding the enzyme's function. In this study, we investigated the influence of the propeptide on the folding and dimerization of recombinant lysosomal dipeptidase. For this purpose, we separately cloned and overexpressed the mature protein and the proenzyme. The overexpressed proteins were localized exclusively to insoluble inclusion bodies. Refolding of the urea-solubilized inclusion bodies showed that only dipeptidase lacking the propeptide was dimeric. The soluble renatured proenzyme was a monomer, although circular dichroism and fluorescence spectra of the proenzyme indicated the formation of secondary and tertiary structure. The propeptide thus controls dimerization, as well as activation, of lysosomal dipeptidase.

  10. Annealing effects on recombinative activity of nickel at direct silicon bonded interface

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Takuto, E-mail: tkojima@toyota-ti.ac.jp; Ohshita, Yoshio; Yamaguchi, Masafumi [Toyota Technological Institute, 2-12-1 Hisakata, Tempaku-ku, Nagoya, 468-8511 (Japan)

    2015-09-15

    By performing capacitance transient analyses, the recombination activity at a (110)/(100) direct silicon bonded (DSB) interface contaminated with nickel diffused at different temperatures, as a model of grain boundaries in multicrystalline silicon, was studied. The trap level depth from the valence band, trap density of states, and hole capture cross section peaked at an annealing temperature of 300 °C. At temperatures ⩾400 °C, the hole capture cross section increased with temperature, but the density of states remained unchanged. Further, synchrotron-based X-ray analyses, microprobe X-ray fluorescence (μ-XRF), and X-ray absorption near edge structure (XANES) analyses were performed. The analysis results indicated that the chemical phase after the sample was annealed at 200 °C was a mixture of NiO and NiSi{sub 2}.

  11. Annealing effects on recombinative activity of nickel at direct silicon bonded interface

    International Nuclear Information System (INIS)

    Kojima, Takuto; Ohshita, Yoshio; Yamaguchi, Masafumi

    2015-01-01

    By performing capacitance transient analyses, the recombination activity at a (110)/(100) direct silicon bonded (DSB) interface contaminated with nickel diffused at different temperatures, as a model of grain boundaries in multicrystalline silicon, was studied. The trap level depth from the valence band, trap density of states, and hole capture cross section peaked at an annealing temperature of 300 °C. At temperatures ⩾400 °C, the hole capture cross section increased with temperature, but the density of states remained unchanged. Further, synchrotron-based X-ray analyses, microprobe X-ray fluorescence (μ-XRF), and X-ray absorption near edge structure (XANES) analyses were performed. The analysis results indicated that the chemical phase after the sample was annealed at 200 °C was a mixture of NiO and NiSi 2

  12. Formation of tissue factor activity following incubation of recombinant human tissue factor apoprotein with plasma lipoproteins

    International Nuclear Information System (INIS)

    Sakai, T.; Kisiel, W.

    1990-01-01

    Incubation of recombinant human tissue factor apoprotein (Apo-TF) with human plasma decreased the recalcified clotting time of this plasma in a time-and dose-dependent manner suggesting relipidation of the Apo-TF by plasma lipoproteins. Incubation of Apo-TF with purified preparations of human very low density, low density and high density lipoproteins resulted in tissue factor activity in a clotting assay. The order of effectiveness was VLDL greater than LDL much greater than HDL. Tissue factor activity generated by incubation of a fixed amount of Apo-TF with plasma lipoproteins was lipoprotein concentration-dependent and saturable. The association of Apo-TF with lipoprotein particles was supported by gel filtration studies in which 125 I-Apo-TF coeluted with the plasma lipoprotein in the void volume of a Superose 6 column in the presence and absence of calcium ions. In addition, void-volume Apo-TF-lipoprotein fractions exhibited tissue factor activity. These results suggest that the factor VIII-bypassing activity of bovine Apo-TF observed in a canine hemophilic model may be due, in part, to its association with plasma lipoproteins and expression of functional tissue factor activity

  13. Long-term stability of recombinant tissue plasminogen activator at -80 C

    Directory of Open Access Journals (Sweden)

    Sperling Matthew

    2009-06-01

    Full Text Available Abstract Background Recombinant tissue plasminogen activator (tPA is a thrombolytic widely used clinically in the treatment of acute thrombotic disease such as ischemic stroke, myocardial infarction, and deep venous thrombosis. This has led to much interest in tPA based lytic therapies leading to laboratory based in-vitro and in-vivo investigations using this drug. However, tPA reconstituted in solution exhibits full activity for only 6–8 hours, according to the manufacturer. Therefore, methods to store reconstituted tPA for long durations while maintaining activity would be of assistance to laboratories using this enzyme. Findings In this work, the enzymatic activity of tPA stored at -80 C over time was measured, using an ELISA technique that measured the amount of active tPA bound to plasminogen activator inhibitor 1 (PAI-1 in a given sample. Sample of tPA solution mixed to a concentration of 1 (mg/ml were stored in cryogenic vials at -80 C for up to 7 years. For a given sample, aliquots were assayed for tPA activity, and compared with a tPA standard to determine relative enzymatic activity. Results are reported as means with standard errors, and 12 measurements were performed for each sample age. Conclusion There was no decrease in tPA activity for samples stored up to 7 years. Such cryogenic storage is a viable method for the preservation of tPA solution for laboratory investigations of tPA-based lytic therapies.

  14. Dendritic cell activation and maturation induced by recombinant calreticulin fragment 39-272.

    Science.gov (United States)

    Li, Yue; Zeng, Xiaoli; He, Lijuan; Yuan, Hui

    2015-01-01

    Dendritic cells (DC) are the most potent antigen-presenting cells for initiating immune responses. DC maturation can be induced by exposing of immature DC to pathogen products or pro-inflammatory factor, which dramatically enhances the ability of DC to activate Ag-specific T cells. In this study, a recombinant calreticulin fragment 39-272 (rCRT/39-272) covering the lectin-like N domain and partial P domain of murine CRT has been expressed and purified in Escherichia coli. Functional analysis studies revealed that rCRT/39-272 has potent immunostimulatory activities in both activating human monocytes and B cells to secrete cytokines. rCRT/39-272 can drive the activation of bone marrow derived DC in TLR4/CD14 dependent way, as indicated by secretion of cytokines IL-12/IL-23 (p40) and IL-1β. Exposure of DC to rCRT/39-272 induces P-Akt, suggesting that rCRT/39-272 induces maturation of DC through PI3K/Akt signaling pathway. The results suggest that soluble rCRT/39-272 is a potent stimulatory agent to DC maturation in TLR4/CD14 and PI3K/Akt dependent pathway. It may play important roles in initiating cellular immunity in vivo and the T cell response in vitro. Thus it could be used for study of DC-based tumor vaccines.

  15. Functional properties of the recombinant kringle-2 domain of tissue plasminogen activator produced in Escherichia coli

    International Nuclear Information System (INIS)

    Wilhelm, O.G.; Jaskunas, S.R.; Vlahos, C.J.; Bang, N.U.

    1990-01-01

    The kringle-2 domain (residues 176-262) of tissue-type plasminogen activator (t-PA) was cloned and expressed in Escherichia coli. The recombinant peptide, which concentrated in cytoplasmic inclusion bodies, was isolated, solubilized, chemically refolded, and purified by affinity chromatography on lysine-Sepharose to apparent homogeneity. [35S]Cysteine-methionine-labeled polypeptide was used to study the interactions of kringle-2 with lysine, fibrin, and plasminogen activator inhibitor-1. The kringle-2 domain bound to lysine-Sepharose and to preformed fibrin with a Kd = 104 +/- 6.2 microM (0.86 +/- 0.012 binding site) and a Kd = 4.2 +/- 1.05 microM (0.80 +/- 0.081 binding site), respectively. Competition experiments and direct binding studies showed that the kringle-2 domain is required for the formation of the ternary t-PA-plasminogen-intact fibrin complex and that the association between the t-PA kringle-2 domain and fibrin does not require plasmin degradation of fibrin and exposure of new COOH-terminal lysine residues. We also observed that kringle-2 forms a complex with highly purified guanidine-activated plasminogen activator inhibitor-1, dissociable by 0.2 M epsilon-aminocaproic acid. The kringle-2 polypeptide significantly inhibited tissue plasminogen activator/plasminogen activator inhibitor-1 interaction. The kringle-2 domain bound to plasminogen activator inhibitor-1 in a specific and saturable manner with a Kd = 0.51 +/- 0.055 microM (0.35 +/- 0.026 binding site). Therefore, the t-PA kringle-2 domain is important for the interaction of t-PA not only with fibrin, but also with plasminogen activator inhibitor-1 and thus represents a key structure in the regulation of fibrinolysis

  16. Evaluation of synthase and hemisynthase activities of glucosamine-6-phosphate synthase by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Gaucher-Wieczorek, Florence; Guérineau, Vincent; Touboul, David; Thétiot-Laurent, Sophie; Pelissier, Franck; Badet-Denisot, Marie-Ange; Badet, Bernard; Durand, Philippe

    2014-08-01

    Glucosamine-6-phosphate synthase (GlmS, EC 2.6.1.16) catalyzes the first and rate-limiting step in the hexosamine biosynthetic pathway, leading to the synthesis of uridine-5'-diphospho-N-acetyl-D-glucosamine, the major building block for the edification of peptidoglycan in bacteria, chitin in fungi, and glycoproteins in mammals. This bisubstrate enzyme converts D-fructose-6-phosphate (Fru-6P) and L-glutamine (Gln) into D-glucosamine-6-phosphate (GlcN-6P) and L-glutamate (Glu), respectively. We previously demonstrated that matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) allows determination of the kinetic parameters of the synthase activity. We propose here to refine the experimental protocol to quantify Glu and GlcN-6P, allowing determination of both hemisynthase and synthase parameters from a single assay kinetic experiment, while avoiding interferences encountered in other assays. It is the first time that MALDI-MS is used to survey the activity of a bisubstrate enzyme. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Recombinant activated factor VII: its mechanism of action and role in the control of hemorrhage.

    Science.gov (United States)

    Allen, Geoffrey A; Hoffman, Maureane; Roberts, Harold R; Monroe, Dougald M

    2002-12-01

    Recombinant activated factor VII (rFVIIa) has proven both safe and efficacious in the treatment of bleeding episodes in patients with hemophilia A or B who have developed inhibitors. More recently, a growing number of reports suggests that rFVIIa may also have indications for the treatment of bleeding in patients with other hemostatic disorders, including qualitative and quantitative platelet defects, factor deficiencies other than hemophilia, and in otherwise healthy patients with uncontrollable hemorrhage following surgery or trauma. We have attempted to reconcile the various proposed mechanisms of action of rFVIIa with its apparent efficacy in such diverse clinical settings. A review of the literature was performed to determine those clinical scenarios in which rFVIIa appears to have been effective in controlling associated hemorrhage. Findings from our group and others have demonstrated that rFVIIa is able to directly activate factor X and increase thrombin production on the surface of activated platelets in the absence of factor VIII or IX, as well as to improve thrombin generation in thrombocytopenia, and to yield a fibrin dot more resistant to fibrinolysis in vitro. Through these primary mechanisms, we believe that rFVIIa may be able to compensate for a variety of defects in hemostasis and merits further investigation as a general therapeutic for uncontrollable hemorrhage.

  18. Treatment of massive gastrointestinal bleeding occurred during autologous stem cell transplantation with recombinant activated factor VII and octreotide

    Directory of Open Access Journals (Sweden)

    Erman Atas

    2015-01-01

    Full Text Available After hematopoietic stem cell transplantation (HSCT, patients may suffer from bleeding. One of the bleeding type is gastrointestinal (GI which has serious morbidity and mortality in children with limited treatment options. Herein, we presented a child with upper GI bleeding post autologous HSCT controlled successfully by using recombinant activated factor VII (rFVIIa and octreotide infusion.

  19. Increased biological activity of deglycosylated recombinant human granulocyte/macrophage colony-stimulating factor produced by yeast or animal cells

    International Nuclear Information System (INIS)

    Moonen, P.; Mermod, J.J.; Ernst, J.F.; Hirschi, M.; DeLamarter, J.F.

    1987-01-01

    Human granulocyte/macrophage colony-stimulating factor (hGM-CSF) produced by several recombinant sources including Escherichia coli, yeast, and animal cells was studied. Recombinant animal cells produced hGM-CSF in low quantities and in multiple forms of varying size. Mammalian hGM-CSF was purified 200,000-fold using immunoaffinity and lectin chromatography. Partially purified proteins produced in yeast and mammalian cells were assayed for the effects of deglycosylation. Following enzymatic deglycosylation, immunoreactivity was measured by radioimmunoassay and biological activity was measured in vitro on responsive human primary cells. Removal of N-linked oligosaccharides from both proteins increased their immunoreactivities by 4- to 8-fold. Removal of these oligosaccharides also increased their specific biological activities about 20-fold, to reach approximately the specific activity of recombinant hGM-CSF from E. coli. The E. coli produced-protein-lacking any carbohydrate- had by far the highest specific activity observed for the recombinant hGM-CSFs

  20. Activation of human T cells by a tumor vaccine infected with recombinant Newcastle disease virus producing IL-2

    NARCIS (Netherlands)

    Janke, M.; Peeters, B.; Zhao, H.; Leeuw, O.; Moormann, R.J.M.; Arnold, A.; Ziouta, Y.; Fournier, P.; Schirrmacher, V.

    2008-01-01

    A new recombinant (rec) Newcastle disease virus (NDV) with incorporated human interleukin 2 (IL-2) as foreign therapeutic gene [rec(IL-2)] will be described. The foreign gene in rec(IL-2) did not affect the main features of NDV replication nor its tumor selectivity. Biologically active IL-2 was

  1. Recombinant tissue plasminogen activator as a novel treatment option for infective endocarditis: a retrospective clinical study in 32 children.

    Science.gov (United States)

    Levitas, Aviva; Krymko, Hanna; Richardson, Justin; Zalzstein, Eli; Ioffe, Viktoriya

    2016-01-01

    Infective endocarditis is a life-threatening infectious syndrome, with high morbidity and mortality. Current treatments for infective endocarditis include intravenous antibiotics, surgery, and involve a lengthy hospital stay. We hypothesised that adjunctive recombinant tissue plasminogen activator treatment for infective endocarditis may facilitate faster resolution of vegetations and clearance of positive blood cultures, and therefore decrease morbidity and mortality. This retrospective study included follow-up of patients, from 1997 through 2014, including clinical presentation, causative organism, length of treatment, morbidity, and mortality. We identified 32 patients, all of whom were diagnosed with endocarditis and were treated by recombinant tissue plasminogen activator. Among all, 27 patients (93%) had positive blood cultures, with the most frequent organisms being Staphylococcus epidermis (nine patients), Staphylococcus aureus (six patients), and Candida (nine patients). Upon treatment, in 31 patients (97%), resolution of vegetations and clearance of blood cultures occurred within hours to few days. Out of 32 patients, one patient (3%) died and three patients (9%) suffered embolic or haemorrhagic events, possibly related to the recombinant tissue plasminogen activator. None of the patients required surgical intervention to assist vegetation resolution. In conclusion, it appears that recombinant tissue plasminogen activator may become an adjunctive treatment for infective endocarditis and may decrease morbidity as compared with current guidelines. Prospective multi-centre studies are required to validate our findings.

  2. Bioconjugation of recombinant tissue plasminogen activator to magnetic nanocarriers for targeted thrombolysis

    Directory of Open Access Journals (Sweden)

    Yang HW

    2012-10-01

    Full Text Available Hung-Wei Yang,1,* Mu-Yi Hua,1,* Kun-Ju Lin,2,* Shiaw-Pyng Wey,3 Rung-Ywan Tsai,4 Siao-Yun Wu,5 Yi-Ching Lu,5 Hao-Li Liu,6 Tony Wu,7 Yunn-Hwa Ma5 1Chang Gung Molecular Medicine Research Center, Department of Chemical and Materials Engineering, 2Molecular Imaging Center, Department of Nuclear Medicine, Chang Gung Memorial Hospital, Kuei-Shan, Tao-Yuan, Taiwan, Republic of China; 3Department of Medical Imaging and Radiological Sciences, 4Electronics and Optoelectronics Research Laboratories, Industrial Technology Research Institute, Hsin-chu, Taiwan, Republic of China; 5Department of Physiology and Pharmacology and Healthy Aging Research Center, 6Department of Electrical Engineering, Chang Gung University, Kuei-Shan, Tao-Yuan, Taiwan, Republic of China; 7Department of Neurology, Chang Gung University College of Medicine and Memorial Hospital, Tao-Yuan, Taiwan, Republic of China*These authors contributed equally to this workAbstract: Low-toxicity magnetic nanocarriers (MNCs composed of a shell of poly [aniline-co-N-(1-one-butyric acid aniline] over a Fe3O4 magnetic nanoparticle core were developed to carry recombinant tissue plasminogen activator (rtPA in MNC-rtPA for targeted thrombolysis. With an average diameter of 14.8 nm, the MNCs exerted superparamagnetic properties. Up to 276 µg of active rtPA was immobilized per mg of MNCs, and the stability of the immobilized rtPA was greatly improved during storage at 4°C and 25°C. In vitro thrombolysis testing with a tubing system demonstrated that magnet-guided MNC-rtPA showed significantly improved thrombolysis compared with free rtPA and reduced the clot lysis time from 39.2 ± 3.2 minutes to 10.8 ± 4.2 minutes. In addition, magnet-guided MNC-rtPA at 20% of the regular rtPA dose restored blood flow within 15–25 minutes of treatment in a rat embolism model without triggering hematological toxicity. In conclusion, this improved system is based on magnetic targeting accelerated thrombolysis and is

  3. Influence of natural and recombinant interferons on development of antiviral condition and activity of natural killers

    International Nuclear Information System (INIS)

    Kuznetsov, V.P.; Avdeev, G.I.; Vyadro, M.M.; Leikin, Yu.D.; Frolova, I.S.

    1986-01-01

    For the purpose of a preliminary estimate of the therapeutic potential of domestic recombinant alpha 2 -component of human leukocytic interferon (rl) in vitro tests, the authors studied its ability to induce development of antiviral condition in diploid culture of human embryo fibroblasts and to activate the cytolytic effect of natural killers in relation to tumor cells, of the K-562 leukemia line and cells of lung adenocarcinoma. The authors used a medicinal form of rL which was derived by expression of a reconstructed gene in Escherichia coli cells. Part of the tests were conducted with an analogous preparation synthesized using another producer, Pseudomonas sp). The biological effect of both preparations was the same. For comparison, a natural preparation was used in all tests: human leukocytic interferon for injection, II(le). The authors studied activity of natural killers in a fraction of mononuclears isolated from blood of essentially healthy donors and from cancer patients. Cells were incubated for 2 h with various concentrations of interferons, then combined in a ratio of 25-50:1 with target cells labeled with 51 Cr. Cytotoxic reaction was conducted for 4 (4-CTR) or 18 h (18-CTR) at 37 0 C. Natural killers could thus be divided into two subpopulations: killer (4-CTR) and cytotoxic (18-CTR) cells. In preliminary tests, both preparations possessed the ability to active natural killers. The effective concentration for rL was within the limits of 1000-2000 IU/ml, and 50-200 Iu/ml for Le. The data on activation of natural killers in 16 oncological patients (primarily with lung cancer), the authors established that both rL and Le induced activation of natural killers in the overwhelming majority of cases in relation to K-562 target cells and adenocarcinomas of the lung

  4. Restricted expression of recombination activating gene (RAG-1) in mouse lymphoid tissues

    International Nuclear Information System (INIS)

    Yamamoto, Akihito; Fujinaga, Hiroyuki; Hamatani, Kiyohiro; Atsuta, Mitsuru.

    1993-03-01

    In an attempt to determine the distribution of recombinase activity in the mouse thymus, spleen, and lymph nodes, we used the in situ hybridization method to examine the expression of the recombination activating genes RAG-1 and RAG-2. Expression of RAG-1 was found in most cortical thymocytes but not in the majority of medullary thymocytes. Although hybridization signals of RAG-2 were not as intense as those of RAG-1, the localization of RAG-2 transcripts was similar to that of RAG-1. In the spleen, expression of RAG-1 was found only in limited cells near the splenic sinus, and the majority of the cells within the follicle were negative for RAG-1 transcript. In nude mice, RAG-1-expressing cells were detected in the same regions, which suggests that in situ hybridization signals of RAG-1 in the spleen are due to the cells of B-cell origin. In the lymph nodes, expression of RAG-1 was found only in the medullary region. Expression of RAG-2 transcript in the spleen and the lymph nodes, if any, was too faint to allow determination of the specific localization. These results suggest that most of the cortical thymocytes and some cells in the spleen are capable of rearranging T-cell receptor genes and immunoglobulin genes, respectively, but the possible involvement of the RAG-1 transcript in RAG-1-positive cells of the spleen and the lymph nodes in functions other than the rearrangement of genes could not be ruled out. (author)

  5. Expression, Purification and Bioactivities Analysis of Recombinant Active Peptide from Shark Liver

    Directory of Open Access Journals (Sweden)

    Boping Ye

    2009-06-01

    Full Text Available The Active Peptide from Shark Liver (APSL was expressed in E. coli BL21 cells. The cDNA encoding APSL protein was obtained from shark regenerated hepatic tissue by RT-PCR, then it was cloned in the pET-28a expression vector. The expressed fusion protein was purified by Ni-IDA affinity chromatography. SDS-PAGE and HPLC analysis showed the purity of the purified fusion protein was more than 98%. The recombinant APSL (rAPSL was tested for its biological activity both in vitro, by its ability to improve the proliferation of SMMC7721 cells, and in vivo, by its significant protective effects against acute hepatic injury induced by CCl4 and AAP (acetaminophen in mice. In addition, the rAPSL could decrease the blood glucose concentration of mice with diabetes mellitus induced by alloxan. Paraffin sections of mouse pancreas tissues showed that rAPSL (3 mg/kg could effectively protect mouse islets from lesions induced by alloxan, which indicated its potential application in theoretical research and industry.

  6. PRDM9 variation strongly influences recombination hot-spot activity and meiotic instability in humans.

    Science.gov (United States)

    Berg, Ingrid L; Neumann, Rita; Lam, Kwan-Wood G; Sarbajna, Shriparna; Odenthal-Hesse, Linda; May, Celia A; Jeffreys, Alec J

    2010-10-01

    PRDM9 has recently been identified as a likely trans regulator of meiotic recombination hot spots in humans and mice. PRDM9 contains a zinc finger array that, in humans, can recognize a short sequence motif associated with hot spots, with binding to this motif possibly triggering hot-spot activity via chromatin remodeling. We now report that human genetic variation at the PRDM9 locus has a strong effect on sperm hot-spot activity, even at hot spots lacking the sequence motif. Subtle changes within the zinc finger array can create hot-spot nonactivating or enhancing variants and can even trigger the appearance of a new hot spot, suggesting that PRDM9 is a major global regulator of hot spots in humans. Variation at the PRDM9 locus also influences aspects of genome instability-specifically, a megabase-scale rearrangement underlying two genomic disorders as well as minisatellite instability-implicating PRDM9 as a risk factor for some pathological genome rearrangements.

  7. Cre Activated and Inactivated Recombinant Adeno-Associated Viral Vectors for Neuronal Anatomical Tracing or Activity Manipulation.

    Science.gov (United States)

    Saunders, Arpiar; Sabatini, Bernardo L

    2015-07-01

    Recombinant adeno-associated viruses (rAAVs) transcriptionally activated by Cre recombinase (Cre-On) are powerful tools for determining the anatomy and function of genetically defined neuronal types in transgenic Cre driver mice. Here we describe how rAAVs transcriptionally inactivated by Cre (Cre-Off) can be used in conjunction with Cre-On rAAVs or genomic Cre-reporter alleles to study brain circuits. Intracranial injection of Cre-On/Cre-Off rAAVs into spatially intermingled Cre(+) and Cre(-) neurons allows these populations to be differentially labeled or manipulated within individual animals. This comparison helps define the unique properties of Cre(+) neurons, highlighting the specialized role they play in their constituent brain circuits. This protocol touches on the conceptual and experimental background of Cre-Off rAAV systems, including caveats and methods of validation. Copyright © 2015 John Wiley & Sons, Inc.

  8. Adsorption/desorption of low concentration of carbonyl sulfide by impregnated activated carbon under micro-oxygen conditions

    International Nuclear Information System (INIS)

    Wang, Xueqian; Qiu, Juan; Ning, Ping; Ren, Xiaoguang; Li, Ziyan; Yin, Zaifei; Chen, Wei; Liu, Wei

    2012-01-01

    Highlights: ► Carbonyl sulfide can be catalytic oxidized by micro-oxygen in the off-gas. ► How to use the trace oxygen for the oxidation of carbonyl sulfide was a challenge. ► The SO 4 2− species in the adsorbent sample were generated by a catalytic oxidation process. - Abstract: Activated carbon modified with different impregnants has been studied for COS removal efficiency under micro-oxygen conditions. Activated carbon modified with Cu(NO 3 ) 2 –CoPcS–KOH (denoted as Cu–Co–KW) is found to have markedly enhanced adsorption purification ability. In the adsorption purification process, the reaction temperature, oxygen concentration, and relative humidity of the gas are determined to be three crucial factors. A breakthrough of 43.34 mg COS/g adsorbent at 60 °S and 30% relative humidity with 1.0% oxygen is shown in Cu–Co–KW for removing COS. The structures of the activated carbon samples are characterized using nitrogen adsorption, and their surface chemical structures are analyzed with X-ray photoelectron spectroscopy (XPS). Modification of Cu(NO 3 ) 2 –CoPcS–KOH appears to improve the COS removal capacity significantly, during which, SO 4 2− is presumably formed, strongly adsorbed, and present in the micropores ranging from 0.7 to 1.5 nm. TPD is used to identify the products containing sulfur species on the carbon surface, where SO 2 and COS are detected in the effluent gas generated from exhausted Cu–Co–KW (denoted Cu–Co–KWE). According to the current study results, the activated carbon impregnated with Cu(NO 3 ) 2 –CoPcS–KOH promises a good candidate for COS adsorbent, with the purified gas meeting requirements for desirable chemical feed stocks.

  9. Adsorption/desorption of low concentration of carbonyl sulfide by impregnated activated carbon under micro-oxygen conditions

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xueqian, E-mail: wxqian3000@yahoo.com.cn [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China); Qiu, Juan; Ning, Ping; Ren, Xiaoguang; Li, Ziyan; Yin, Zaifei; Chen, Wei; Liu, Wei [Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming 650093 (China)

    2012-08-30

    Highlights: Black-Right-Pointing-Pointer Carbonyl sulfide can be catalytic oxidized by micro-oxygen in the off-gas. Black-Right-Pointing-Pointer How to use the trace oxygen for the oxidation of carbonyl sulfide was a challenge. Black-Right-Pointing-Pointer The SO{sub 4}{sup 2-} species in the adsorbent sample were generated by a catalytic oxidation process. - Abstract: Activated carbon modified with different impregnants has been studied for COS removal efficiency under micro-oxygen conditions. Activated carbon modified with Cu(NO{sub 3}){sub 2}-CoPcS-KOH (denoted as Cu-Co-KW) is found to have markedly enhanced adsorption purification ability. In the adsorption purification process, the reaction temperature, oxygen concentration, and relative humidity of the gas are determined to be three crucial factors. A breakthrough of 43.34 mg COS/g adsorbent at 60 Degree-Sign S and 30% relative humidity with 1.0% oxygen is shown in Cu-Co-KW for removing COS. The structures of the activated carbon samples are characterized using nitrogen adsorption, and their surface chemical structures are analyzed with X-ray photoelectron spectroscopy (XPS). Modification of Cu(NO{sub 3}){sub 2}-CoPcS-KOH appears to improve the COS removal capacity significantly, during which, SO{sub 4}{sup 2-} is presumably formed, strongly adsorbed, and present in the micropores ranging from 0.7 to 1.5 nm. TPD is used to identify the products containing sulfur species on the carbon surface, where SO{sub 2} and COS are detected in the effluent gas generated from exhausted Cu-Co-KW (denoted Cu-Co-KWE). According to the current study results, the activated carbon impregnated with Cu(NO{sub 3}){sub 2}-CoPcS-KOH promises a good candidate for COS adsorbent, with the purified gas meeting requirements for desirable chemical feed stocks.

  10. Anomalous low-temperature desorption from preirradiated rare gas solids

    International Nuclear Information System (INIS)

    Savchenko, E.V.; Gumenchuk, G.B.; Yurtaeva, E.M.; Belov, A.G.; Khyzhniy, I.V.; Frankowski, M.; Beyer, M.K.; Smith-Gicklhorn, A.M.; Ponomaryov, A.N.; Bondybey, V.E.

    2005-01-01

    The role for the exciton-induced defects in the stimulation of anomalous low-temperature desorption of the own lattice atoms from solid Ar and Ne preirradiated by an electron beam is studied. The free electrons from shallow traps-structural defects-was monitored by the measurements of a yield of the thermally induced exoelectron emission (TSEE). The reaction of recombination of self-trapped holes with electrons is considered as a source of energy needed for the desorption of atoms from the surface of preirradiated solids. A key part of the exciton-induced defects in the phenomenon observed is demonstrated

  11. Analysis of the technique Thermal Desorption Spectroscopy (TDS) and its Application for the Characterization of Metal -Hydrogen Systems

    International Nuclear Information System (INIS)

    Castro, F.J.

    2000-01-01

    limiting step is the recombination of two hydrogen atoms on the surface of the material. When the surface of the sample is in the a phase (solid solution) the rate limiting step is one of the processes that occurs on the surface of the material: the transfer of a hydrogen atom from the bulk to the surface or the recombination and desorption on the surface. By fitting the spectra we obtain an activation energy equal to 31 n 6 kJ/mol for the b phase, and equal to 35 n 3 kJ/mol for the a phase. We also compare the spectra of the powder with the spectra of the granules, foils and wires. Based on this comparison we analyze the effect on the desorption spectra of the characteristic size and geometry of the samples.Finally, we present a study of hydrogen desorption in the Pd-H system poisoned with sulfur. The poisoning produces as main effects a delay of the absorption and desorption processes without any appreciable loss in the storage capacity of the material.The experimental apparatus and theoretical models developed have been applied to the study of a MH system using samples with different morphology, characteristic size, geometry and surface state. The spectra were measured for different hydrogen concentrations and heating speeds. The results obtained encourage the utilization of TDS for the study and characterization of hydrogen desorption in MH systems. The technique is suited for the detailed analysis of the physical properties of the system and for the qualitative evaluation of the kinetic processes and their possible influence on technological devices

  12. In vitro effects of recombinant activated factor VII on thrombin generation and coagulation following inhibition of platelet procoagulant activity by prasugrel.

    Science.gov (United States)

    Mazzeffi, Michael; Szlam, Fania; Jakubowski, Joseph A; Tanaka, Kenichi A; Sugidachi, Atsuhiro; Levy, Jerrold H

    2013-07-01

    Prasugrel is a thienopyridyl P2Y12 antagonist with potent antiplatelet effects. At present, little is known about its effects on thrombin generation or what strategies may emergently reverse its anticoagulant effects. In the current study we evaluated whether recombinant activated factor VII may reverse prasugrel induced effects and increase thrombin generation in an in vitro model. The effect of prasugrel active metabolite, PAM (R-138727), was evaluated on platelet aggregation, thrombin generation, and rotational thromboelastometry parameters using blood from 20 healthy volunteers. Additionally, we evaluated the effects of adenosine diphosphate (ADP) and recombinant activated factor VII on restoring these parameters towards baseline values. PAM reduced maximum platelet aggregation and led to platelet disaggregation. It also decreased peak thrombin, increased lag time, and increased time to peak thrombin. Treatment with recombinant activated factor VII restored all three parameters of thrombin generation towards baseline. ADP decreased lag time and time to peak thrombin, but had no effect on peak thrombin. When recombinant activated factor VII and ADP were combined they had a greater effect on thrombin parameters than either drug alone. PAM also increased thromboelastometric clotting time and clot formation time, but had no effect on maximum clot firmness. Treatment with either recombinant activated factor VII or ADP restored these values towards baseline. Recombinant activated factor VII restores thrombin generation in the presence of PAM. In patients taking prasugrel with life-threatening refractory bleeding it has the potential to be a useful therapeutic approach. Additional clinical studies are needed to validate our findings. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Analysis of genotoxic activity of ketamine and rocuronium bromide using the somatic mutation and recombination test in Drosophila melanogaster.

    Science.gov (United States)

    Koksal, Pakize Muge; Gürbüzel, Mehmet

    2015-03-01

    The present study evaluated the mutagenic and recombinogenic effects of two commonly used anesthetic agents, ketamine and rocuronium bromide, in medicine using the wing somatic mutation and recombination test (SMART) in Drosophila. The standard (ST) cross and the high-bioactivation (HB) cross with high sensitivity to procarcinogens and promutagens were used. The SMART test is based on the loss of heterozygosity, which occurs via various mechanisms, such as chromosome loss and deletion, half-translocation, mitotic recombination, mutation, and non-disjunction. Genetic alterations occurring in the somatic cells of the wing's imaginal discs result in mutant clones in the wing blade. Three-day-old trans-heterozygous larvae with two recessive markers, multiple wing hairs (mwh) and flare (flr(3)), were treated with ketamine and rocuronium bromide. Analysis of the ST cross indicated that ketamine exhibited genotoxicity activity and that this activity was particularly dependent on homologous mitotic recombination at concentrations of 250 μg/ml and above. Rocuronium bromide did not exert mutagenic and/or recombinogenic effects. In the HB cross, ketamine at a concentration of 1000 μg/ml and rocuronium bromide at all concentrations, with the exception of 250 μg/ml (inconclusive), exerted genotoxic effects, which could also be associated with the increase in mitotic recombination. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Evidence supporting the use of recombinant activated factor VII in congenital bleeding disorders

    Directory of Open Access Journals (Sweden)

    Pär I Johansson

    2010-06-01

    Full Text Available Pär I Johansson, Sisse R OstrowskiCapital Region Blood Bank, Section for Transfusion Medicine, Rigshospitalet, University of Copenhagen, Copenhagen, DenmarkBackground: Recombinant activated factor VII (rFVIIa, NovoSeven® was introduced in 1996 for the treatment of hemophilic patients with antibodies against coagulation factor VIII or IX.Objective: To review the evidence supporting the use of rFVIIa for the treatment of patients with congenital bleeding disorders.Patients and methods: English-language databases were searched in September 2009 for reports of randomized controlled trials (RCTs evaluating the ability of rFVIIa to restore hemostasis in patients with congenital bleeding disorders.Results: Eight RCTs involving 256 hemophilic patients with antibodies against coagulation factors, also known as inhibitors, were identified. The evidence supporting the use of rFVIIa in these patients was weak with regard to dose, clinical setting, mode of administration, efficacy, and adverse events, given the limited sample size of each RCT and the heterogeneity of the studies.Conclusion: The authors suggest that rFVIIa therapy in hemophilic patients with inhibitors should be based on the individual’s ability to generate thrombin and form a clot, and not on the patient’s weight alone. Therefore, assays for thrombin generation, such as whole-blood thromboelastography, have the potential to significantly improve the treatment of these patients.Keywords: hemophilia, inhibitors, coagulation factor VIII, coagulation factor IX, rFVIIa, NovoSeven, FEIBA, hemostasis, RCT

  15. Novel recombinant adeno-associated viruses for Cre activated and inactivated transgene expression in neurons

    Science.gov (United States)

    Saunders, Arpiar; Johnson, Caroline A.; Sabatini, Bernardo L.

    2012-01-01

    Understanding the organization of the nervous system requires methods for dissecting the contributions of each component cell type to circuit function. One widely used approach combines genetic targeting of Cre recombinase to specific cell populations with infection of recombinant adeno-associated viruses (rAAVs) whose transgene expression is activated by Cre (“Cre-On”). Distinguishing how the Cre-expressing neurons differ functionally from neighboring Cre-negative neurons requires rAAVs that are inactivated by Cre (“Cre-Off”) and can be used in tandem with Cre-On viruses. Here we introduce two rAAV vectors that are inactivated by Cre and carry different fluorophore and optogenetic constructs. We demonstrate single and dual rAAV systems to achieve Cre-On and Cre-Off expression in spatially-intermingled cell populations of the striatum. Using these systems, we uncovered cryptic genomic interactions that occur between multiple Cre-sensitive rAAVs or between Cre-sensitive rAAVs and somatic Cre-conditional alleles and devised methods to avoid these interactions. Our data highlight both important experimental caveats associated with Cre-dependent rAAV use as well as opportunities for the development of improved rAAVs for gene delivery. PMID:22866029

  16. Constitutive cellulase production from glucose using the recombinant Trichoderma reesei strain overexpressing an artificial transcription activator.

    Science.gov (United States)

    Zhang, Xiaoyue; Li, Yonghao; Zhao, Xinqing; Bai, Fengwu

    2017-01-01

    The high cost of cellulase production presents biggest challenge in biomass deconstruction. Cellulase production by Trichoderma reesei using low cost carbon source is of great interest. In this study, an artificial transcription activator containing the Cre1 binding domain linked to the Xyr1 effector and binding domains was designed and constitutively overexpressed in T. reesei RUT C30. The recombinant strain T. reesei zxy-2 displayed constitutive cellulase production using glucose as a sole carbon source, and the production titer was 12.75-fold of that observed with T. reesei RUT C30 in shake flask culture. Moreover, FPase and xylanase titers of 2.63 and 108.72IU/mL, respectively, were achieved using glucose as sole carbon source within 48h in a 7-L fermenter by batch fermentation using T. reesei zxy-2. The crude enzyme obtained was used to hydrolyze alkali pretreated corn stover, and a high glucose yield of 99.18% was achieved. Copyright © 2016. Published by Elsevier Ltd.

  17. Recombinant interleukin 2 stimulates in vivo proliferation of adoptively transferred lymphokine-activated killer (LAK) cells

    International Nuclear Information System (INIS)

    Ettinghausen, S.E.; Lipford, E.H. III; Mule, J.J.; Rosenberg, S.A.

    1985-01-01

    The authors previously reported that the adoptive transfer of lymphokine-activated killer (LAK) cells plus repetitive injections of recombinant interleukin 2 (IL 2) produced a marked reduction in established pulmonary metastases from a variety of murine sarcomas. The requirement for the exogenous administration of IL 2 prompted a subsequent examination of the role of IL 2 in the in vivo function of transferred LAK cells. The in vivo proliferation and migration patterns of lymphoid cells in C57BL/6 mice were examined after i.v. transfer of LAK cells alone, i.p. injection of IL 2 alone, or the combination of LAK cells and IL 2. A model for in vivo labeling of the DNA of dividing cells was used in which mice were injected with 5-[ 125 I]-iodo-2'-deoxyuridine ( 125 IUdR) and, 20 hr later, their tissues were removed and were counted in a gamma analyzer. A proliferation index (PI) was calculated by dividing the mean cpm of organs of experimentally treated mice by the mean cpm of organs of control mice. In animals given LAK cells alone, the lungs and liver demonstrated little if any uptake of 125 IUdR above saline-treated controls, whereas the same organs of mice receiving 6000 U of IL 2 alone displayed higher radiolabel incorporation. When mice were given LAK cells plus 6000 U of IL 2, their tissues showed an additional increase in 125 IUdR uptake

  18. Experimental study on removals of SO2 and NOX using adsorption of activated carbon/microwave desorption.

    Science.gov (United States)

    Ma, Shuang-Chen; Yao, Juan-Juan; Gao, Li; Ma, Xiao-Ying; Zhao, Yi

    2012-09-01

    Experimental studies on desulfurization and denitrification were carried out using activated carbon irradiated by microwave. The influences of the concentrations of nitric oxide (NO) and sulfur dioxide (SO 2 ), the flue gas coexisting compositions, on adsorption properties of activated carbon and efficiencies of desulfurization and denitrification were investigated. The results show that adsorption capacity and removal efficiency of NO decrease with the increasing of SO 2 concentrations in flue gas; adsorption capacity of NO increases slightly first and drops to 12.79 mg/g, and desulfurization efficiency descends with the increasing SO 2 concentrations. Adsorption capacity of SO 2 declines with the increasing of O 2 content in flue gas, but adsorption capacity of NO increases, and removal efficiencies of NO and SO 2 could be larger than 99%. Adsorption capacity of NO declines with the increase of moisture in the flue gas, but adsorption capacity of SO 2 increases and removal efficiencies of NO and SO 2 would be relatively stable. Adsorption capacities of both NO and SO 2 decrease with the increasing of CO 2 content; efficiencies of desulfurization and denitrification augment at the beginning stage, then start to fall when CO 2 content exceeds 12.4%. The mechanisms of this process are also discussed. [Box: see text].

  19. The activation process of ZrCo by an adsorption-desorption cycle of H{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunmi; Paek, Seungwoo; Lee, Minsoo; Kim, Sihyung; Kim, Kwangrag; Ahn, Dohee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Sohn, Soonhwan; Song, Kyumin [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2008-05-15

    Along with uranium, a zirconium-cobalt intermetallic compound has been extensively studied and widely used due to its attractive properties as a tritium getter for a handling, transport, and storage of tritium. The zirconium-cobalt has two strong advantages compared with uranium. While uranium is restricted for a handling due to its radioactive characteristics, zirconium-cobalt is easy to handle. Also, from the point of view of a safety, zirconium-cobalt and its hydrides have proven to be much less pyrophoric than uranium and its hydrides are the most widely used as a tritium getter. However, the zirconium-cobalt has one shortcoming in that it brings about a disproportionation at above 673 K. In the current study, before the experiment for the pressure-composition isotherm of zirconium-cobalt at room temperature, the activation process of the zirconium-cobalt intermetallic compound was dealt with and its result was discussed.

  20. Batch sorption-desorption of As(III) from waste water by magnetic palm kernel shell activated carbon using optimized Box-Behnken design

    Science.gov (United States)

    Anyika, Chinedum; Asri, Nur Asilayana Mohd; Majid, Zaiton Abdul; Jaafar, Jafariah; Yahya, Adibah

    2017-12-01

    In this study, we converted activated carbon (AC) into magnetic activated carbon (MAC), which was established to have removed arsenic (III) from wastewater. Arsenic (III) is a toxic heavy metal which is readily soluble in water and can be detrimental to human health. The MAC was prepared by incorporating Fe3O4 into the AC by using Fe3O4 extracted from a ferrous sulfate solution, designated: magnetic palm kernel shell from iron suspension (MPKSF). Batch experiments were conducted using two methods: (1) one-factor-at-a-time and (2) Box-Behnken statistical analysis. Results showed that the optimum conditions resulted in 95% of As(III) removal in the wastewater sample. The adsorption data were best fitted to the Langmuir isotherm. The adsorption of As(III) onto the MPKSF was confirmed by energy dispersive X-ray spectrometry analysis which detected the presence of As(III) of 0.52% on the surface of the MPKSF. The Fourier transform infrared spectroscopy analysis of the MPKSF-As presented a peak at 573 cm-1, which was assigned to M-O (metal-oxygen) bending, indicating the coordination of As(III) with oxygen through the formation of inner-sphere complexation, thereby indicating a covalent bonding between the MPKSF functional groups and As(III). The findings suggested that the MPKSF exhibited a strong capacity to efficiently remove As(III) from wastewater, while the desorption studies showed that the As(III) was rigidly bound to the MPKSF thereby eliminating the possibility of secondary pollution.

  1. Endogenous acute phase serum amyloid A lacks pro-inflammatory activity, contrasting the two recombinant variants that activate human neutrophils through different receptors

    Directory of Open Access Journals (Sweden)

    Karin eChristenson

    2013-04-01

    Full Text Available Most notable among the acute phase proteins is serum amyloid A (SAA, levels of which can increase 1000-fold during infections, aseptic inflammation, and/or trauma. Chronically elevated SAA levels are associated with a wide variety of pathological conditions, including obesity and rheumatic diseases. Using a recombinant hybrid of the two human SAA isoforms (SAA1 and 2 that does not exist in vivo, numerous in vitro studies have given rise to the notion that acute phase SAA is a pro-inflammatory molecule with cytokine-like properties. It is however unclear whether endogenous acute phase SAA per se mediates pro-inflammatory effects. We tested this in samples from patients with inflammatory arthritis and in a transgenic mouse model that expresses human SAA1. Endogenous human SAA did not drive production of pro-inflammatory IL-8/KC in either of these settings. Human neutrophils derived from arthritis patients displayed no signs of activation, despite being exposed to severely elevated SAA levels in circulation, and SAA-rich sera also failed to activate cells in vitro. In contrast, two recombinant SAA variants (the hybrid SAA and SAA1 both activated human neutrophils, inducing L-selectin shedding, production of reactive oxygen species, and production of IL-8. The hybrid SAA was approximately 100-fold more potent than recombinant SAA1. Recombinant hybrid SAA and SAA1 activated neutrophils through different receptors, with recombinant SAA1 being a ligand for formyl peptide receptor 2 (FPR2. We conclude that even though recombinant SAAs can be valuable tools for studying neutrophil activation, they do not reflect the nature of the endogenous protein.

  2. Expression and characterization of recombinant single-chain salmon class I MHC fused with beta2-microglobulin with biological activity

    DEFF Research Database (Denmark)

    Zhao, Heng; Stet, René J M; Skjødt, Karsten

    2008-01-01

    Heterodimeric class I major histocompatibility complex (MHC) molecules consist of a putative 45-kDa heavy chain and a 12-kDa beta2-microglobulin (beta2m) light chain. The knowledge about MHC genes in Atlantic salmon accumulated during the last decade has allowed us to generate soluble and stable ...... MHC class I molecules with biological activity. We report here the use of a bacterial expression system to produce the recombinant single-chain MHC molecules based on a specific allele Sasa-UBA*0301. This particular allele was selected because previous work has shown its association...... antibodies were successfully produced against both the MHC class I heavy chain and beta(2)m, and showed binding to the recombinant molecule. The recombinant complex Sasabeta2mUBA*0301 was expressed and isolated; the production was scaled up by adjusting to its optimal conditions. Subsequently......, the recombinant proteins were purified by affinity chromatography using mAb against beta2m and alpha3. Eluates were analyzed by Western blot and refolded by the removal of denaturant. The correct folding was confirmed by measuring its binding capacity against mAb produced to recognize the native form of MHC...

  3. Recombinant Programming

    OpenAIRE

    Pawlak , Renaud; Cuesta , Carlos; Younessi , Houman

    2004-01-01

    This research report presents a promising new approach to computation called Recombinant Programming. The novelty of our approach is that it separates the program into two layers of computation: the recombination and the interpretation layer. The recombination layer takes sequences as inputs and allows the programmer to recombine these sequences through the definition of cohesive code units called extensions. The output of such recombination is a mesh that can be used by the interpretation la...

  4. Potency of full-length MGF to induce maximal activation of the IGF-I R Is similar to recombinant human IGF-I at high equimolar concentrations

    NARCIS (Netherlands)

    J.A.M.J.L. Janssen (Joseph); L.J. Hofland (Leo); C.J. Strasburger; E.S.R.D. Van Dungen (Elisabeth S.R. Den); M. Thevis (Mario)

    2016-01-01

    textabstractAims To compare full-length mechano growth factor (full-length MGF) with human recombinant insulin-like growth factor-I (IGF-I) and human recombinant insulin (HI) in their ability to activate the human IGF-I receptor (IGF-IR), the human insulin receptor (IR-A) and the human insulin

  5. Intravenous recombinant tissue plasminogen activator for acute ischemic stroke: a feasibility and safety study

    Directory of Open Access Journals (Sweden)

    Sadeghi-Hokmabadi E

    2016-10-01

    Full Text Available Elyar Sadeghi-Hokmabadi, Mehdi Farhoudi, Aliakbar Taheraghdam, Mazyar Hashemilar, Daryous Savadi-Osguei, Reza Rikhtegar, Kaveh Mehrvar, Ehsan Sharifipour, Parisa Youhanaee, Reshad Mirnour Neurosciences Research Center, Neurology Department, Tabriz University of Medical Sciences, Tabriz, East Azerbaijan, Iran Background: In developing countries, intravenous thrombolysis (IVT is available at a limited number of centers. This study aimed to assess the feasibility and safety of IVT at Tabriz Imam Reza Hospital. Methods: In a prospective study, over a 55-month period, any patient at the hospital for whom stroke code had been activated was enrolled in the study. Data on demographic characteristics, stroke risk factors, admission blood pressure, blood tests, findings of brain computed tomography (CT scans, time of symtom onset, time of arrival to the emergency department, time of stroke code activation, time of CT scan examination, and the time of recombinant tissue plasminogen activator administration were recorded. National Institutes of Health Stroke Scale assessments were performed before IVT bolus, at 36 hours, at either 7 days or discharge (which ever one was earlier, and at 3-month follow-up. Brain CT scans were done for all patients before and 24 hours after the treatment. Results: Stroke code was activated for 407 patients and IVT was done in 168 patients. The rate of functional independence (modified Rankin Scale [mRS] 0–1 at 3 months was 39.2% (62/158. The mortality rate at day 7 was 6% (10/168. Hemorrhagic transformation was noted in 16 patients (9.5%. Symptomatic intracranial hemorrhage occurred in 5 (3%, all of which were fatal. One case of severe urinary bleeding and one other fatal case of severe angioedema were observed. Conclusion: During the first 4–5 years of administration of IVT in the hospital, it was found to be feasible and safe, but to increase the efficacy, poststroke care should be more organized and a stroke center

  6. Acoustic emission during hydrogen absorption and desorption in palladium

    International Nuclear Information System (INIS)

    Ramesh, R.; Mukhopadhyay, C.K.; Jayakumar, T.; Baldev Raj

    1996-01-01

    Acoustic emission technique has been used to study charging and discharging of hydrogen in palladium. During charging, breaking of oxide film due to surface activation and saturation of hydrogen absorption have been identified by acoustic emission. In the discharging cycle, the desorption of hydrogen from the specimen leads to high AE activity immediately after initiation of discharging, followed by gradual decrease in the acoustic activity, which reaches a minimum upon completion of the desorption. The potential of the acoustic emission technique for studying the kinetics of hydrogen absorption and desorption in metals has been shown. (author)

  7. Preparation of thermosensitive magnetic liposome encapsulated recombinant tissue plasminogen activator for targeted thrombolysis

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, Hao-Lung [Department of Chemical and Materials Engineering, Chang Gung University, Kwei-San, Taoyuan 33302, Taiwan, ROC (China); Chen, Jyh-Ping, E-mail: jpchen@mail.cgu.edu.tw [Department of Chemical and Materials Engineering, Chang Gung University, Kwei-San, Taoyuan 33302, Taiwan, ROC (China); Department of Plastic and Reconstructive Surgery and Craniofacial Research Center, Chang Gung Memorial Hospital, Kwei-San, Taoyuan 33305, Taiwan, ROC (China); Graduate Institute of Health Industry and Technology, Research Center for Industry of Human Ecology, Chang Gung University of Science and Technology, Kwei-San, Taoyuan 33302, Taiwan, ROC (China); Department of Materials Engineering, Ming Chi University of Technology, Tai-Shan, New Taipei City 24301, Taiwan, ROC (China)

    2017-04-01

    Recombinant tissue plasminogen activator (rtPA) was encapsulated in thermosensitive magnetic liposome (TML) prepared from 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, distearolyphosphatidyl ethanolamine-N-poly(ethylene glycol) 2000, cholesterol and Fe{sub 3}O{sub 4} magnetic nanoparticles by solvent evaporation/sonication and freeze-thaw cycles method. Response surface methodology was proved to be a powerful tool to predict the drug encapsulation efficiency and temperature-sensitive drug release. Validation experiments verified the accuracy of the model that provides a simple and effective method for fabricating TML with controllable encapsulation efficiency and predictable temperature-sensitive drug release behavior. The prepared samples were characterized for physico-chemical properties by dynamic light scattering, transmission electron microscopy, X-ray diffraction and differential scanning calorimetry. Temperature-sensitive release of rtPA could be confirmed from in vitro thrombolysis experiments. A thrombolytic drug delivery system using TML could be proposed for magnetic targeted delivery of rtPA to the site of thrombus followed by temperature-triggered controlled drug release in an alternating magnetic field. - Highlights: • rtPA and Fe{sub 3}O{sub 4} MNP were encapsulated in thermosensitive magnetic liposome (TML). • RSM could predict the drug encapsulation efficiency and temperature-sensitive drug release from TML. • Temperature-sensitive release of rtPA was confirmed from in vitro thrombolysis experiments. • TML-rtPA will be useful as a magnetic targeted nanodrug to improve clinical thrombolytic therapy.

  8. Novel recombinant human lactoferrin: differential activation of oxidative stress related gene expression.

    Science.gov (United States)

    Kruzel, Marian L; Actor, Jeffrey K; Zimecki, Michał; Wise, Jasen; Płoszaj, Paulina; Mirza, Shaper; Kruzel, Mark; Hwang, Shen-An; Ba, Xueqing; Boldogh, Istvan

    2013-12-01

    Lactoferrin, an iron-binding protein found in high concentrations in mammalian exocrine secretions, is an important component of the host defense system. It is also a major protein of the secondary granules of neutrophils from which is released upon activation. Due to its potential clinical utility, recombinant human lactoferrin (rhLF) has been produced in various eukaryotic expression systems; however, none of these are fully compatible with humans. Most of the biopharmaceuticals approved by the FDA for use in humans are produced in mammalian expression systems. The Chinese hamster ovary cells (CHO) have become the system of choice for proteins that require post-translational modifications, such as glycoproteins. The aim of this study was to scale-up expression and purification of rhLF in a CHO expression system, verify its glycan primary structure, and assess its biological properties in cell culture models. A stable CHO cell line producing >200mg/L of rhLF was developed and established. rhLF was purified by a single-step cation-exchange chromatography procedure. The highly homogenous rhLF has a molecular weight of approximately 80 kDa. MALDI-TOF mass spectrometric analysis revealed N-linked, partially sialylated glycans at two glycosylation sites, typical for human milk LF. This novel rhLF showed a protective effect against oxidative stress in a similar manner to its natural counterpart. In addition, rhLF revealed a modulatory effect on cellular redox via upregulation of key antioxidant enzymes. These data imply that the CHO-derived rhLF is fully compatible with the native molecule, thus it has promise for human therapeutic applications. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. The Effect of Recombinant Activated Factor VII on Mortality in Combat-Related Casualties With Severe Trauma and Massive Transfusion

    Science.gov (United States)

    2008-02-01

    acidosis and hypocalcemia are corrected. In addition, these guidelines recommend rFVIIa for patients with adequate concentrations of platelets, fibrinogen...1.00 Data on physiologic cause of death available for 51 of 53 deaths recorded. rFVIIa, recombinant activated factor VII; CNS, central nervous ... system ; MOF, multi-organ failure. Table 10 Comparison of Adverse Events Between Study Groups Variable rFVIIa N 75 rFVIIa N 49 p Value Bacteremia 12

  10. Evaluation of recombinant activated protein C for severe sepsis at a tertiary academic medical center

    Directory of Open Access Journals (Sweden)

    Anger KE

    2013-06-01

    Full Text Available Kevin E Anger,1 Jeremy R DeGrado,1 Bonnie C Greenwood,1 Steven A Cohen,2 Paul M Szumita1 1Department of Pharmacy, Brigham and Women’s Hospital, Boston, MA, USA; 2Department of Family Medicine and Population Health, Division of Epidemiology, Virginia Commonwealth University, Richmond, VA, USA Purpose: Early clinical trials of recombinant human activated protein C (rhAPC for severe sepsis excluded patients at high risk of bleeding. Recent literature suggests bleeding rates are higher in clinical practice and may be associated with worsened outcomes. Our objective was to evaluate baseline demographics; incidence, and risk factors for major bleeding; and mortality of patients receiving rhAPC for severe sepsis at our institution. Methods: A retrospective study was performed for all patients receiving rhAPC for treatment of severe sepsis at a tertiary academic medical center from January 2002 to June 2009. Demographic information, clinical variables, intensive care unit, and hospital outcomes were recorded. Results: Of the 156 patients that received rhAPC, 54 (34.6% did not meet institutional criteria for safe use at baseline due to bleeding precaution or contraindication. Twenty-three (14.7% patients experienced a major bleeding event. Multivariate analysis demonstrated baseline International Normalized Ratio ≥2.5 (odds ratio [OR] 3.68, 95% confidence interval [CI]: 1.28–10.56; P = 0.03 and platelet count ≤100 × 103/mm3 (OR 2.86, 95% CI: 1.07–7.67; P = 0.01 as significant predictors of a major bleed. Overall hospital mortality was 57.7%. Multivariate analysis demonstrated the presence of ≥3 organ dysfunctions (OR 2.46, 95% CI: 1.19–5.09; P < 0.05 and medical intensive care unit admission (OR 1.99, 95% CI: 1.00–3.98; P = 0.05 were independent variables associated with hospital mortality. Conclusion: Patients receiving rhAPC at our institution had higher APACHE II scores, mortality, and major bleeding events than published

  11. Expression of active recombinant human alpha 1-antitrypsin in transgenic rabbits

    NARCIS (Netherlands)

    Massoud, M.; Bischoff, Rainer; Dalemans, W.; Pointu, H.; Attal, J.; Schultz, H.; Clesse, D.; Stinnakre, M.G.; Pavirani, A.; Houdebine, L.M.

    1991-01-01

    A DNA construct containing the human alpha 1-antitrypsin gene including 1.5 and 4 kb of 5' and 3' flanking sequences, was microinjected into the pronucleus of rabbit embryos. The recombinant human protein was (a) expressed in the blood circulation of F0 and F1 transgenic rabbits at an average

  12. Influence of cardiopulmonary bypass on the interaction of recombinant factor VIIa with activated platelets

    DEFF Research Database (Denmark)

    Kjalke, M.; Runge, M.; Rojkjaer, R.

    2009-01-01

    Recombinant factor VIIa (rFVIIa) interacts preferentially with coated platelets characterized by a high exposure of phosphatidyl serine (PS), FV, FVIII, FIX, and FX binding, and fibrinogen. Cardiopulmonary bypass (CPB) is known to impair platelet function. In this study, the influence of CPB...

  13. Intraoperative use of low-dose recombinant activated factor VII during thoracic aortic operations.

    Science.gov (United States)

    Andersen, Nicholas D; Bhattacharya, Syamal D; Williams, Judson B; Fosbol, Emil L; Lockhart, Evelyn L; Patel, Mayur B; Gaca, Jeffrey G; Welsby, Ian J; Hughes, G Chad

    2012-06-01

    Numerous studies have supported the effectiveness of recombinant activated factor VII (rFVIIa) for the control of bleeding after cardiac procedures; however safety concerns persist. Here we report the novel use of intraoperative low-dose rFVIIa in thoracic aortic operations, a strategy intended to improve safety by minimizing rFVIIa exposure. Between July 2005 and December 2010, 425 consecutive patients at a single referral center underwent thoracic aortic operations with cardiopulmonary bypass (CPB); 77 of these patients received intraoperative low-dose rFVIIa (≤60 μg/kg) for severe coagulopathy after CPB. Propensity matching produced a cohort of 88 patients (44 received intraoperative low-dose rFVIIa and 44 controls) for comparison. Matched patients receiving intraoperative low-dose rFVIIa got an initial median dose of 32 μg/kg (interquartile range [IQR], 16-43 μg/kg) rFVIIa given 51 minutes (42-67 minutes) after separation from CPB. Patients receiving intraoperative low-dose rFVIIa demonstrated improved postoperative coagulation measurements (partial thromboplastin time 28.6 versus 31.5 seconds; p=0.05; international normalized ratio, 0.8 versus 1.2; pproduct transfusions (2.5 versus 5.0 units; p=0.05) compared with control patients. No patient receiving intraoperative low-dose rFVIIa required postoperative rFVIIa administration or reexploration for bleeding. Rates of stroke, thromboembolism, myocardial infarction, and other adverse events were equivalent between groups. Intraoperative low-dose rFVIIa led to improved postoperative hemostasis with no apparent increase in adverse events. Intraoperative rFVIIa administration in appropriately selected patients may correct coagulopathy early in the course of refractory blood loss and lead to improved safety through the use of smaller rFVIIa doses. Appropriately powered randomized studies are necessary to confirm the safety and efficacy of this approach. Copyright © 2012 The Society of Thoracic Surgeons

  14. Plasmid construction using recombination activity in the fission yeast Schizosaccharomyces pombe.

    Directory of Open Access Journals (Sweden)

    Ayako Chino

    Full Text Available BACKGROUND: Construction of plasmids is crucial in modern genetic manipulation. As of now, the common method for constructing plasmids is to digest specific DNA sequences with restriction enzymes and to ligate the resulting DNA fragments with DNA ligase. Another potent method to construct plasmids, known as gap-repair cloning (GRC, is commonly used in the budding yeast Saccharomyces cerevisiae. GRC makes use of the homologous recombination activity that occurs within the yeast cells. Due to its flexible design and efficiency, GRC has been frequently used for constructing plasmids with complex structures as well as genome-wide plasmid collections. Although there have been reports indicating GRC feasibility in the fission yeast Schizosaccharomyces pombe, this species is not commonly used for GRC as systematic studies of reporting GRC efficiency in S. pombe have not been performed till date. METHODOLOGY/PRINCIPAL FINDINGS: We investigated GRC efficiency in S. pombe in this study. We first showed that GRC was feasible in S. pombe by constructing a plasmid that contained the LEU2 auxotrophic marker gene in vivo and showed sufficient efficiency with short homology sequences (>25 bp. No preference was shown for the sequence length from the cut site in the vector plasmid. We next showed that plasmids could be constructed in a proper way using 3 DNA fragments with 70% efficiency without any specific selections being made. The GRC efficiency with 3 DNA fragments was dramatically increased >95% in lig4Delta mutant cell, where non-homologous end joining is deficient. Following this approach, we successfully constructed plasmid vectors with leu1+, ade6+, his5+, and lys1+ markers with the low-copy stable plasmid pDblet as a backbone by applying GRC in S. pombe. CONCLUSIONS/SIGNIFICANCE: We concluded that GRC was sufficiently feasible in S. pombe for genome-wide gene functional analysis as well as for regular plasmid construction. Plasmids with different

  15. [Clinical characteristics of human recombination activating gene 1 mutations in 8 immunodeficiency patients with diverse phenotypes].

    Science.gov (United States)

    Yu, G; Wang, W J; Liu, D R; Tao, Z F; Hui, X Y; Hou, J; Sun, J Q; Wang, X C

    2018-03-02

    Objective: To investigate the clinical characteristics of 8 immunodeficiency cases caused by human recombination activating gene 1 (RAG1) mutations, and to explore the relationship among genotypes, clinical manifestations and immunophenotypes. Methods: Clinical data were collected and analyzed from patients with RAG1 mutations who visited the Department of Clinical Immunology, Children's Hospital of Fudan University between October 2013 and June 2017. The data included clinical manifestations, immunophenotypes and genotypes. Results: A total of 8 patients were diagnosed with RAG1 deficiency (6 boys and 2 girls). The minimum age of onset was 2 months, and the maximum age was 4 months. The minimum age of diagnosis was 2 months, and the maximum age was 13 years. Four patients had a family history of infant death due to severe infections. Two cases were born to the same consanguineous parents. All cases had recurrent infections, including involvement of respiratory tract (8 cases), digestive tract (6 cases), urinary tract (1 case), and central nervous system (1 case). The pathogens of infection included bacteria, viruses and fungi. Rotavirus was found in 3 cases, cytomegalovirus (CMV) in 5 cases, bacillus Calmette-Guérin adverse reaction in 2 cases (1 of whom had a positive acid-fast smear from lymph node puncture fluid), fungal infection in 3 cases. One case had multiple nodular space-occupying lesions in lungs and abdominal cavity complicated with multiple bone destruction. The peripheral blood lymphocyte counts of all patients ranged between 0.1 ×10(9)/L and 3.3×10(9)/L (median, 0.65×10(9)/L). Eosinophilia was found in 3 cases (range, (0.48-1.69) ×10(9)/L). The patients were classified according to immunophenotype as severe combined immunodeficiency phenotype (4 cases), leaky severe combined immunodeficiency (2 cases), Omenn syndrome (1 case) and combined immunodeficiency (1 case) . Decreased serum IgG levels were found in 3 cases, increased serum IgM levels in

  16. Prophylactic administration of recombinant activated factor VII in coronary revascularization surgery

    Directory of Open Access Journals (Sweden)

    Mohamed Essam Abdel-Meguid

    2013-01-01

    Full Text Available Objective: The objective of this clinical trial is to study the effectiveness of administering recombinant activated factor VII (rFVIIa in reducing the amount of bleeding and the need for homologous blood and products transfusion in cardiac surgical coronary revascularization procedures done under cardiopulmonary bypass (CPB. Methods: In a randomized controlled prospective observational study, 30 patients were scheduled for elective cardiac revascularization under CPB. Patients were randomly allocated into two groups. In Group I (Control group, no rFVIIa was administered following CPB. In Group II (Study group, a dose of 90 ug/Kg of rFVIIa was administered following weaning off CPB. The total amount of chest tube drain during the 1 st 24 h following surgery was recorded as well as the qualitative and quantitative assessments of homologous blood and products transfusion. Serial analysis of hematological parameters including hemoglobin level and coagulation test in a definite data points was done. T0=baseline readings prior to CPB, T1=off CPB after protamine administration and before administration of the study drug, T2=on Cardiac Intensive Care Unit (CICU admission, T3=12 h post-CICU admission, and T4=24 h post-CICU admission. Results: Considering the total chest tube drainage, mean values showed statistically significant results with a P value of 0.001. Homologous blood and products transfusion were statistically lower in the study group. Regarding the mean values for hematological assessment, results showed statistically lower International Normalized Ratio values at CICU admission and 12 h post-CICU admission with a P value of 0.018 and 0.004, respectively. Also, the Partial Thromboplastin Time mean values were statistically lower at same timings with estimated P values of 0.04 and 0.001, respectively. Conclusion: It is concluded that the prophylactic use of rFVIIa in patients undergoing coronary revascularization surgery under the management

  17. Crystallization and preliminary crystallographic analysis of latent, active and recombinantly expressed aurone synthase, a polyphenol oxidase, from Coreopsis grandiflora

    Energy Technology Data Exchange (ETDEWEB)

    Molitor, Christian; Mauracher, Stephan Gerhard; Rompel, Annette, E-mail: annette.rompel@univie.ac.at [Universität Wien, Althanstrasse 14, 1090 Wien (Austria)

    2015-05-22

    Latent and active aurone synthase purified from petals of C. grandiflora (cgAUS1) were crystallized. The crystal quality of recombinantly expressed latent cgAUS1 was significantly improved by co-crystallization with the polyoxotungstate Na{sub 6}[TeW{sub 6}O{sub 24}] within the liquid–liquid phase-separation zone. Aurone synthase (AUS), a member of a novel group of plant polyphenol oxidases (PPOs), catalyzes the oxidative conversion of chalcones to aurones. Two active cgAUS1 (41.6 kDa) forms that differed in the level of phosphorylation or sulfation as well as the latent precursor form (58.9 kDa) were purified from the petals of Coreopsis grandiflora. The differing active cgAUS1 forms and the latent cgAUS1 as well as recombinantly expressed latent cgAUS1 were crystallized, resulting in six different crystal forms. The active forms crystallized in space groups P2{sub 1}2{sub 1}2{sub 1} and P12{sub 1}1 and diffracted to ∼1.65 Å resolution. Co-crystallization of active cgAUS1 with 1,4-resorcinol led to crystals belonging to space group P3{sub 1}21. The crystals of latent cgAUS1 belonged to space group P12{sub 1}1 and diffracted to 2.50 Å resolution. Co-crystallization of recombinantly expressed pro-AUS with the hexatungstotellurate(VI) salt Na{sub 6}[TeW{sub 6}O{sub 24}] within the liquid–liquid phase separation zone significantly improved the quality of the crystals compared with crystals obtained without hexatungstotellurate(VI)

  18. Increased volume of distribution for recombinant activated factor VII and longer plasma-derived factor VII half-life may explain their long lasting prophylactic effect.

    Science.gov (United States)

    Mathijssen, Natascha C J; Masereeuw, Rosalinde; Holme, Pal Andre; van Kraaij, Marian G J; Laros-van Gorkom, Britta A P; Peyvandi, Flora; van Heerde, Waander L

    2013-08-01

    Prophylaxis with plasma-derived or recombinant activated factor VII is beneficial in severe factor VII deficiency. To understand why prophylactic treatment with both products is efficacious, we conducted a pharmacokinetic study. Ten factor VII deficient patients were treated with either recombinant activated (20 μg/kg) or plasma-derived (25 IU/kg) factor VII in a cross-over design. Pharmacokinetic parameters were analyzed through activated factor VII activity, factor VII clotting activity, and factor VII antigen levels on depicted time points. Factor VII activity half-lifes, determined by non-compartmental and one-compartmental analysis (results in brackets), were shorter for recombinant activated (1.4h; 0.7h) than for plasma-derived factor VII (6.8h; 3.2h); both recombinant activated (5.1h; 2.1h and plasma-derived factor VII (5.8h; 3.2h) resulted in longer half-lives of factor VII antigen. Activated factor VII half-lives (based on activated factor VII activity levels) were significantly higher compared to factor VII clotting activity (1.6h; 0.9h). Volumes of distribution were significantly higher for activated factor VII (236 ml/kg; 175 ml/kg, measured by activated factor VII) as compared to plasma-derived factor VII (206 ml/kg; 64 ml/kg, measured by factor FVII activity), suggesting a plasma- and extracellular fluid distribution for recombinant activated factor VII. Recombinant activated factor VII showed significantly shorter half-lifes than plasma-derived factor VII. Volumes of distribution were significantly higher for treatment with recombinant activated factor VII. The longer half-life for plasma-derived factor VII, compared to recombinant activated factor VII, and the increased volume of distribution for recombinant activated factor VII, compared to plasma-derived factor VII may further elucidate the beneficial effect of prophylactic treatment of both products. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. A new impedance based approach to test the activity of recombinant protein--Semaphorins as a test case.

    Science.gov (United States)

    Birger, Anastasya; Besser, Elazar; Reubinoff, Benjamin; Behar, Oded

    2015-10-01

    The biological activity of a recombinant protein is routinely measured using a bioassay such as an enzyme assay. However, many proteins have no enzymatic activity and in many cases it is difficult to devise a simple and reliable approach to test their activity. Semaphorins, Ephrins, Slits, Netrins or amylin-assisted proteins have numerous activities affecting many systems and cell types in the human body. Most of them are also able to induce rapid cytoskeleton changes at least in some cell types. We assumed therefore, that such proteins might be tested based on their ability to modulate the cytoskeleton. Here we tested a number of semaphorins in an impedance based label-free platform that allows for dynamic monitoring of subtle morphological and adhesive changes. This system has proved to be a very fast, sensitive and effective way to monitor and determine the activity of such proteins. Furthermore we showed that it is possible to customize a cell-protein system by transfecting the cells with specific receptors and test the cell response following the addition of the recombinant ligand protein. Since other protein families such as Ephrins and Netrins can also influence the cytoskeleton of some cells, this approach may be applicable to a large number of proteins. Copyright © 2015 Elsevier GmbH. All rights reserved.

  20. Superoxide dismutase recombinant Lactobacillus fermentum ameliorates intestinal oxidative stress through inhibiting NF-κB activation in a trinitrobenzene sulphonic acid-induced colitis mouse model.

    Science.gov (United States)

    Hou, C L; Zhang, J; Liu, X T; Liu, H; Zeng, X F; Qiao, S Y

    2014-06-01

    Superoxide dismutase (SOD) can prevent and cure inflammatory bowel diseases by decreasing the amount of reactive oxygen species. Unfortunately, short half-life of SOD in the gastrointestinal tract limited its application in the intestinal tract. This study aimed to investigate the treatment effects of recombinant SOD Lactobacillus fermentum in a colitis mouse model. In this study, we expressed the sodA gene in Lact. fermentum I5007 to obtain the SOD recombinant strain. Then, we determined the therapeutic effects of this SOD recombinant strain in a trinitrobenzene sulphonic acid (TNBS)-induced colitis mouse model. We found that SOD activity in the recombinant Lact. fermentum was increased by almost eightfold compared with that in the wild type. Additionally, both the wild type and the recombinant Lact. fermentum increased the numbers of lactobacilli in the colon of mice (P < 0·05). Colitis mice treated with recombinant Lact. fermentum showed a higher survival rate and lower disease activity index (P < 0·05). Recombinant Lact. fermentum significantly decreased colonic mucosa histological scoring for infiltration of inflammatory cells, lipid peroxidation, the expression of pro-inflammatory cytokines and myeloperoxidase (P < 0·05) and inhibited NF-κB activity in colitis mice (P < 0·05). SOD recombinant Lact. fermentum significantly reduced oxidative stress and inflammation through inhibiting NF-κB activation in the TNBS-induced colitis model. This study provides insights into the anti-inflammatory effects of SOD recombinant Lact. fermentum, indicating the potential therapeutic effects in preventing and curing intestinal bowel diseases. © 2014 The Society for Applied Microbiology.

  1. Activity of the Human Rhinovirus 3C Protease Studied in Various Buffers, Additives and Detergents Solutions for Recombinant Protein Production.

    Directory of Open Access Journals (Sweden)

    Raheem Ullah

    Full Text Available Proteases are widely used to remove affinity and solubility tags from recombinant proteins to avoid potential interference of these tags with the structure and function of the fusion partner. In recent years, great interest has been seen in use of the human rhinovirus 3C protease owing to its stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious and time-consuming procedures before proteolysis can occur. To address this issue, we examined the effect of elution buffers used for common affinity based purifications, salt ions, stability/solubility and reducing agents, and detergents on the activity of the human rhinovirus 3C protease using three different fusion proteins at 4°C, a temperature of choice for purification of many proteins. The results show that the human rhinovirus 3C protease performs better at 4°C than the frequently used tobacco etch virus protease and its activity was insensitive to most of the experimental conditions tested. Though number of fusion proteins tested is limited, we expect that these finding will facilitate the use of the human rhinovirus 3C protease in recombinant protein production for pharmaceutical and biotechnological applications.

  2. Activity of the Human Rhinovirus 3C Protease Studied in Various Buffers, Additives and Detergents Solutions for Recombinant Protein Production.

    Science.gov (United States)

    Ullah, Raheem; Shah, Majid Ali; Tufail, Soban; Ismat, Fouzia; Imran, Muhammad; Iqbal, Mazhar; Mirza, Osman; Rhaman, Moazur

    2016-01-01

    Proteases are widely used to remove affinity and solubility tags from recombinant proteins to avoid potential interference of these tags with the structure and function of the fusion partner. In recent years, great interest has been seen in use of the human rhinovirus 3C protease owing to its stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious and time-consuming procedures before proteolysis can occur. To address this issue, we examined the effect of elution buffers used for common affinity based purifications, salt ions, stability/solubility and reducing agents, and detergents on the activity of the human rhinovirus 3C protease using three different fusion proteins at 4°C, a temperature of choice for purification of many proteins. The results show that the human rhinovirus 3C protease performs better at 4°C than the frequently used tobacco etch virus protease and its activity was insensitive to most of the experimental conditions tested. Though number of fusion proteins tested is limited, we expect that these finding will facilitate the use of the human rhinovirus 3C protease in recombinant protein production for pharmaceutical and biotechnological applications.

  3. The 3'-to-5' exonuclease activity of vaccinia virus DNA polymerase is essential and plays a role in promoting virus genetic recombination.

    Science.gov (United States)

    Gammon, Don B; Evans, David H

    2009-05-01

    Poxviruses are subjected to extraordinarily high levels of genetic recombination during infection, although the enzymes catalyzing these reactions have never been identified. However, it is clear that virus-encoded DNA polymerases play some unknown yet critical role in virus recombination. Using a novel, antiviral-drug-based strategy to dissect recombination and replication reactions, we now show that the 3'-to-5' proofreading exonuclease activity of the viral DNA polymerase plays a key role in promoting recombination reactions. Linear DNA substrates were prepared containing the dCMP analog cidofovir (CDV) incorporated into the 3' ends of the molecules. The drug blocked the formation of concatemeric recombinant molecules in vitro in a process that was catalyzed by the proofreading activity of vaccinia virus DNA polymerase. Recombinant formation was also blocked when CDV-containing recombination substrates were transfected into cells infected with wild-type vaccinia virus. These inhibitory effects could be overcome if CDV-containing substrates were transfected into cells infected with CDV-resistant (CDV(r)) viruses, but only when resistance was linked to an A314T substitution mutation mapping within the 3'-to-5' exonuclease domain of the viral polymerase. Viruses encoding a CDV(r) mutation in the polymerase domain still exhibited a CDV-induced recombination deficiency. The A314T substitution also enhanced the enzyme's capacity to excise CDV molecules from the 3' ends of duplex DNA and to recombine these DNAs in vitro, as judged from experiments using purified mutant DNA polymerase. The 3'-to-5' exonuclease activity appears to be an essential virus function, and our results suggest that this might be because poxviruses use it to promote genetic exchange.

  4. Whole-genome analysis of genetic recombination of hepatitis delta virus: molecular domain in delta antigen determining trans-activating efficiency.

    Science.gov (United States)

    Chao, Mei; Lin, Chia-Chi; Lin, Feng-Ming; Li, Hsin-Pai; Iang, Shan-Bei

    2015-12-01

    Hepatitis delta virus (HDV) is the only animal RNA virus that has an unbranched rod-like genome with ribozyme activity and is replicated by host RNA polymerase. HDV RNA recombination was previously demonstrated in patients and in cultured cells by analysis of a region corresponding to the C terminus of the delta antigen (HDAg), the only viral-encoded protein. Here, a whole-genome recombination map of HDV was constructed using an experimental system in which two HDV-1 sequences were co-transfected into cultured cells and the recombinants were analysed by sequencing of cloned reverse transcription-PCR products. Fifty homologous recombinants with 60 crossovers mapping to 22 junctions were identified from 200 analysed clones. Small HDAg chimeras harbouring a junction newly detected in the recombination map were then constructed. The results further indicated that the genome-replication level of HDV was sensitive to the sixth amino acid within the N-terminal 22 aa of HDAg. Therefore, the recombination map established in this study provided a tool for not only understanding HDV RNA recombination, but also elucidating the related mechanisms, such as molecular elements responsible for the trans-activation levels of the small HDAg.

  5. Heterologous expression of a truncated form of human recombinant vascular endothelial growth factor-A and its biological activity in wound healing.

    Science.gov (United States)

    Khaki, Mohsen; Salmanian, Ali Hatef; Mosayebi, Ghasem; Baazm, Maryam; Babaei, Saeed; Molaee, Neda; Abtahi, Hamid

    2017-07-01

    Vascular endothelial growth factor (VEGF) is one of the most effective proteins in angiogenesis, mesenchymal stem cells (MSCs) differentiation and wound healing. These abilities are therapeutic potential of VEGF in diabetic retinopathy, nephropathy and other tissue damage circumstances. In this study, recombinant VEGF was produced in Escherichia coli ( E. coli ) system and then biological activity of this protein was evaluated in animal wound healing. E. coli BL21 (DE3) competent cells were transformed with pET32a-VEGF clone and induced by isopropyl-β-D-thio-galactoside (IPTG). The recombinant protein was purified by affinity chromatography. Recombinant VEGF-A-based ointment (VEGF/Vaseline 0.8 mg/100 w/w) was used for external wound (25×15mm thickness) healing in animal model. In vivo activity of ointment was evaluated by clinical evidences and cytological microscopic assessment. The recombinant protein with molecular weight of 45 kilodaltons (kDa) and concentration of 0.8 mg/ml was produced. Immunoblotting data showed that the antigenic region of VEGF can be expressed in E. coli and the recombinant protein has similar epitopes with close antigenic properties to the natural form. Macroscopic findings and microscopic data showed that the recombinant VEGF-A ointment was effective on excisional wound healing. Recombinant VEGF-A produced by pET32a in E. coli , possesses acceptable structure and has wound healing capability.

  6. Heterologous expression of a truncated form of human recombinant vascular endothelial growth factor-A and its biological activity in wound healing

    Directory of Open Access Journals (Sweden)

    Mohsen Khaki

    2017-07-01

    Full Text Available Objective(s: Vascular endothelial growth factor (VEGF is one of the most effective proteins in angiogenesis, mesenchymal stem cells (MSCs differentiation and wound healing. These abilities are therapeutic potential of VEGF in diabetic retinopathy, nephropathy and other tissue damage circumstances. In this study, recombinant VEGF was produced in Escherichia coli (E. coli system and then biological activity of this protein was evaluated in animal wound healing. Materials and Methods: E. coli BL21 (DE3 competent cells were transformed with pET32a-VEGF clone and induced by isopropyl-β-D-thio-galactoside (IPTG. The recombinant protein was purified byaffinity chromatography. Recombinant VEGF-A-based ointment (VEGF/Vaseline 0.8 mg/100 w/w was used for external wound (25×15mm thickness healing in animal model. In vivo activity of ointment was evaluated by clinical evidences and cytological microscopic assessment. Results: The recombinant protein with molecular weight of 45 kilodaltons (kDa and concentration of 0.8 mg/ml was produced.Immunoblotting data showed that the antigenic region of VEGF can be expressed in E. coli and the recombinant protein has similar epitopes with close antigenic properties to the natural form. Macroscopic findings and microscopic data showed that the recombinant VEGF-A ointment was effective on excisional wound healing. Conclusion: Recombinant VEGF-A produced by pET32a in E. coli, possesses acceptable structure and has wound healing capability.

  7. Expression and Purification of Active Recombinant Cathepsin C (Dipeptidyl Aminopeptidase I of Kuruma Prawn Marsupenaeus japonicus in Insect Cells

    Directory of Open Access Journals (Sweden)

    Gao-Feng Qiu

    2009-01-01

    Full Text Available Cathepsin C (CTSC is a lysosomal cysteine protease belonging to the papain superfamily. Our previous study showed that CTSC precursor (zymogen is localized exclusively in cortical rods (CRs of mature oocyte in the kuruma prawn Marsupenaeus japonicus, suggesting that CTSC might have roles on regulating release and/or formation of a jelly layer. In this study, enzymically active CTSC of the kuruma prawn was prepared by recombinant expression in the High Five insect cell line. The recombinant enzyme with a polyhistidine tag at its C-terminus was considered to be initially secreted into the culture medium as an inactive form of zymogen, because Western blot with anti-CTSC antibody detected a 51 kDa protein corresponding to CTSC precursor. After purification by affinity chromatography on nickel-iminodiacetic acid resin, the enzyme displayed three forms of 51, 31, and 30 kDa polypeptides. All of the forms can be recognized by antiserum raised against C-terminal polyhistidine tag, indicating that the 31 and 30 kDa forms were generated from 51 kDa polypeptide by removal of a portion of the N-terminus of propeptide. Following activation at pH 5.5 and 37∘C for 40 hours under native conditions, the recombinant CTSC (rCTSC exhibited increased activity against the synthetic substrate Gly-Phe-β-naphthylamide and optimal pH at around 5. The purified rCTSC will be useful for further characterization of its exact physiological role on CRs release and/or formation of a jelly layer in kuruma prawn.

  8. Outcome of stroke patients receiving different doses of recombinant tissue plasminogen activator.

    Science.gov (United States)

    Ong, Cheung-Ter; Wong, Yi-Sin; Wu, Chi-Shun; Su, Yu-Hsiang

    2017-01-01

    Intravenous recombinant tissue plasminogen activator (tPA) at a dose of 0.9 mg/kg body weight is associated with a high hemorrhagic transformation (HT) rate. Low-dose tPA (0.6 mg/kg) may have a lower hemorrhage rate but the mortality and disability rates at 90 days cannot be confirmed as non-inferior to standard-dose tPA. Whether the doses 0.7 and 0.8 mg/kg have better efficacy and safety needs further investigation. Therefore, this study is to compare the efficacy and safety of each dose of tPA (0.6, 0.7, 0.8, and 0.9 mg/kg body weight) and to investigate the factors affecting early neurological improvement (ENI) and early neurological deterioration (END). For this observational study, data were obtained from 274 patients who received tPA thrombolytic therapy in Chia-Yi Christian Hospital stroke unit. The tPA dose was given at the discretion of each physician. The definition of ENI was a >8 point improvement (compared with baseline) at 24 h following thrombolytic therapy or an improvement in the National Institutes of Health Stroke Score (NIHSS) to 0 or 1 toward the end of tPA infusion. The definition of END was a >4 point increase in NIHSS (compared with baseline) within 24 h of tPA infusion. The primary objective was to investigate whether 0.7 and 0.8 mg/kg of tPA have higher ENI rate, lower END rate, and better outcome at 6 months. Poor outcome was defined as having a modified Rankin Scale of 3 to 6 (range, 0 [no symptoms] to 6 [death]). The secondary objective was to investigate whether low-dose tPA has a lower risk of intracerebral HT than that with standard-dose tPA. We also investigated the factors affecting ENI, END, HT, and 6-month outcome. A total of 274 patients were included during the study period, of whom 260 were followed up for >6 months. There was a trend for the HT rate to increase as the dose increased ( P =0.02). The symptomatic HT rate was not significantly different among the low-dose and standard-dose groups. The ENI and END ( P =0.52) were

  9. Continuous infusion of recombinant activated factor VII for bleeding control after lobectomy in a patient with inherited factor VII deficiency.

    Science.gov (United States)

    Miyata, Naoko; Isaka, Mitsuhiro; Kojima, Hideaki; Maniwa, Tomohiro; Takahashi, Shoji; Takamiya, Osamu; Ohde, Yasuhisa

    2016-03-01

    Inherited factor VII (FVII) deficiency is a rare recessive inherited coagulation disorder with limited available information, especially in patients undergoing major thoracic surgery. In addition, an optimal management strategy for the disease has not been defined. We herein report a case involving a 61-year-old man with asymptomatic FVII deficiency who underwent a right middle and lower lobectomy to treat lung cancer. To the best of our knowledge, the present report is the first to describe the use of recombinant activated FVII continuous infusion for bleeding control after a major thoracic surgery in a patient with inherited FVII deficiency.

  10. A Novel Cold-Active Lipase from Candida albicans: Cloning, Expression and Characterization of the Recombinant Enzyme

    Directory of Open Access Journals (Sweden)

    Dong-Ming Lan

    2011-06-01

    Full Text Available A novel lipase gene lip5 from the yeast Candida albicans was cloned and sequenced. Alignment of amino acid sequences revealed that 86–34% identity exists with lipases from other Candida species. The lipase and its mutants were expressed in the yeast Pichia pastoris, where alternative codon usage caused the mistranslation of 154-Ser and 293-Ser as leucine. 154-Ser to leucine resulted in loss of expression of Lip5, and 293-Ser to leucine caused a marked reduction in the lipase activity. Lip5-DM, which has double mutations that revert 154 and 293 to serine residues, showed good lipase activity, and was overexpressed and purified by (NH42SO4 precipitation and ion-exchange chromatography. The pure Lip5-DM was stable at low temperatures ranging from 15–35 °C and pH 5–9, with the optimal conditions being 15–25 °C and pH 5–6. The activation energy of recombinant lipase was 8.5 Kcal/mol between 5 and 25 °C, suggesting that Lip5-DM was a cold–active lipase. Its activity was found to increase in the presence of Zn2+, but it was strongly inhibited by Fe2+, Fe3+, Hg2+ and some surfactants. In addition, the Lip5-DM could not tolerate water-miscible organic solvents. Lip5-DM exhibited a preference for the short- and medium-chain length p-nitrophenyl (C4 and C8 acyl group esters rather than the long chain length p-nitrophenyl esters (C12, C16 and C18 acyl group with highest activity observed with the C8 derivatives. The recombinant enzyme displayed activity toward triacylglycerols, such as olive oil and safflower oil.

  11. Sorption/desorption reversibility of polycyclic aromatic hydrocarbons (PAHs) in soils and carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guohui

    2008-07-01

    Understanding sorption/desorption is an important prerequisite for the prediction of fate and transport of pollutants in the environment. During the last two decades, numerous studies have reported hysteresis phenomenon for the interaction of hydrophobic organic contaminants (HOCs) with natural organic matter (NOM). It manifests as nonsingular sorption/desorption isotherms or different rates for sorption and desorption, where during desorption a higher affinity of a compound on a given sorbent and a longer time scale for release than for sorption is observed. Other studies showed that some of the reported sorption/desorption hysteresis phenomena are due to experimental artifacts, mainly resulting from non-attainment of sorption equilibrium before desorption experiments, which result in 'pseudo-hysteresis'. Except for the hypothesis of sorbent reconfiguration, clear experimental evidence for the physical or chemical mechanisms proposed to lead to hysteresis is still lacking. In this study, sorption/desorption equilibrium and kinetics of phenanthrene sorption/desorption from two soils and three carbonaceous samples were investigated using both batch and column techniques. The main objective of this work was to monitor hysteresis phenomenon by carefully recovering the solute mass in the system and to compare sorption/desorption equilibria and kinetics thermodynamically. Nonsingular isotherms and higher desorption enthalpies as well as increased activation energies with proceeding desorption are expected if significant hysteresis exists. Sorption-desorption cycles were carried out to compare equilibrium isotherms and associated sorption/desorption enthalpies (AeH, isosteric heats). Instead of the traditional decant-and-refill batch method, the experiments were conducted using a newly designed batch protocol, which enables the determination of sorption/desorption isotherms at different temperatures using a closed batch system. This method additionally allows

  12. Sorption/desorption reversibility of polycyclic aromatic hydrocarbons (PAHs) in soils and carbonaceous materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Guohui

    2008-07-01

    Understanding sorption/desorption is an important prerequisite for the prediction of fate and transport of pollutants in the environment. During the last two decades, numerous studies have reported hysteresis phenomenon for the interaction of hydrophobic organic contaminants (HOCs) with natural organic matter (NOM). It manifests as nonsingular sorption/desorption isotherms or different rates for sorption and desorption, where during desorption a higher affinity of a compound on a given sorbent and a longer time scale for release than for sorption is observed. Other studies showed that some of the reported sorption/desorption hysteresis phenomena are due to experimental artifacts, mainly resulting from non-attainment of sorption equilibrium before desorption experiments, which result in 'pseudo-hysteresis'. Except for the hypothesis of sorbent reconfiguration, clear experimental evidence for the physical or chemical mechanisms proposed to lead to hysteresis is still lacking. In this study, sorption/desorption equilibrium and kinetics of phenanthrene sorption/desorption from two soils and three carbonaceous samples were investigated using both batch and column techniques. The main objective of this work was to monitor hysteresis phenomenon by carefully recovering the solute mass in the system and to compare sorption/desorption equilibria and kinetics thermodynamically. Nonsingular isotherms and higher desorption enthalpies as well as increased activation energies with proceeding desorption are expected if significant hysteresis exists. Sorption-desorption cycles were carried out to compare equilibrium isotherms and associated sorption/desorption enthalpies (AeH, isosteric heats). Instead of the traditional decant-and-refill batch method, the experiments were conducted using a newly designed batch protocol, which enables the determination of sorption/desorption isotherms at different temperatures using a closed batch system. This method additionally allows the

  13. The glycoprotein Ib-IX-V complex contributes to tissue factor-independent thrombin generation by recombinant factor VIIa on the activated platelet surface

    NARCIS (Netherlands)

    Weeterings, Cees; de Groot, Philip G.; Adelmeijer, Jelle; Lisman, Ton

    2008-01-01

    Several lines of evidence suggest that recombinant factor VIIa (rFVIIa) is able to activate factor X on an activated platelet, in a tissue factor-independent manner. We hypothesized that, besides the anionic surface, a receptor on the activated platelet surface is involved in this process. Here, we

  14. Electrocatalytic activity of a mononuclear yttrium(III)–methyl orange complex and Y{sub 2}O{sub 2}SO{sub 4} nanoparticles for adsorption/desorption of hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Shafaie, Fahimeh [Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Hadadzadeh, Hassan, E-mail: hadad@cc.iut.ac.ir [Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Behnamfar, Mohammad Taghi [Department of Chemistry, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Rudbari, Hadi Amiri [Faculty of Chemistry, University of Isfahan, Isfahan, 81746-73441 (Iran, Islamic Republic of)

    2016-12-01

    A new mononuclear yttrium(III) complex, [Y(MO){sub 3}(DMF){sub 3}(H{sub 2}O){sub 2}] (where MO{sup –} is methyl orange anion (4-[(4-dimethylamino)phenyldiazenyl]benzenesulfonate)), was synthesized in an aqueous solution. The complex was characterized by elemental analysis, UV/Vis, FT-IR, and single-crystal X-ray crystallography. The yttrium oxysulfate nanoparticles (Y{sub 2}O{sub 2}SO{sub 4}) were then prepared by calcination of [Y(MO){sub 3}(DMF){sub 3}(H{sub 2}O){sub 2}]. The obtained nanoparticles were characterized by FT-IR, X-ray diffraction analysis (XRD), and field-emission scanning electron microscopy (FE-SEM). The hydrogen adsorption/desorption (H{sub ads}/H{sub des}) behavior of the Y(III) complex and Y{sub 2}O{sub 2}SO{sub 4} nanoparticles was studied at a carbon paste electrode (CPE) in H{sub 2}SO{sub 4} by cyclic voltammetry (CV). The recorded voltammograms exhibited a pair of peaks corresponding to the adsorption/desorption of hydrogen for the Y(III) complex and Y{sub 2}O{sub 2}SO{sub 4} nanoparticles. The results show a reversible hydrogen adsorption/desorption reaction for both compounds. The voltammograms of the nanoparticles indicate an excellent cycling stability for the adsorption/desorption of hydrogen. In addition, the linear sweep voltammetry (LSV) technique was used to investigate the electrocatalytic activity of both compounds for the hydrogen adsorption reaction. The linear voltammograms of both compounds demonstrate the excellent electrocatalytic activity for the hydrogen adsorption reaction. - Highlights: • Preparation of a new Y(III) complex and Y{sub 2}O{sub 2}SO{sub 4} nanoparticles. • Investigation of the H{sub ads}/H{sub des} reaction for both compounds by voltammetry. • Observation of two peaks corresponding to the H{sub ads}/H{sub des} in both compounds. • An excellent cycling stability for the nanoparticles in H{sub 2}SO{sub 4}.

  15. PROTECTIVE ACTIVITY STUDY OF A CANDIDATE VACCINE AGAINST ROTAVIRUS INFECTION BASED ON RECOMBINANT PROTEIN FliCVP6VP8

    Directory of Open Access Journals (Sweden)

    I. V. Dukhovlinov

    2016-01-01

    Full Text Available Rotavirus infection is among leading causes of severe diarrhea which often leads to severe dehydration, especially, in children under 5 years old. In Russia, the incidence of rotavirus infection is constantly increased, due to higher rates of actual rotavirus infection cases and improved diagnostics of the disease. Immunity to rotavirus is unstable, thus causing repeated infections intra vitam. Anti-infectious resistance in reconvalescents is explained by induction of specific IgM, IgG, and, notably, IgA antibodies. Due to absence of market drugs with direct action against rotavirus, a rational vaccination is considered the most effective way to control the disease. Currently available vaccines for prevention of rotavirus infection are based on live attenuated rotavirus strains, human and/or animal origin, which replicate in human gut. Their implementation may result into different complications. Meanwhile, usage of vaccines based on recombinant proteins is aimed to avoid risks associated with introduction of a complete virus into humans. In this paper, we studied protective activity of candidate vaccines against rotavirus.In this work we studied protective activity of a candidate vaccine against rotavirus infection based on recombinant FliCVP6VP8 protein which includes VP6 and VP8, as well as components of Salmonella typhimurium flagellin (FliC as an adjuvant. Different components are joined by flexible bridges. Efficiency of the candidate vaccine was studied in animal model using Balb/c mice. We have shown high level of protection which occurs when the candidate vaccine is administered twice intramuscularly. Complete protection of animals against mouse rotavirus EDC after intramuscular immunization with a candidate vaccine was associated with arising rotavirus-specific IgA and IgG antibodies in serum and intestine of immunized animals. The efficacy of candidate vaccine based on recombinant protein FliCVP6VP8 against rotavirus infection was

  16. Assessment of the adjuvant activity of mesoporous silica nanoparticles in recombinant Mycoplasma hyopneumoniae antigen vaccines

    Directory of Open Access Journals (Sweden)

    Veridiana Gomes Virginio

    2017-01-01

    Full Text Available The adjuvant potential of two mesoporous silica nanoparticles (MSNs, SBa-15 and SBa-16, was assessed in combination with a recombinant HSP70 surface polypeptide domain from Mycoplasma hyopneumoniae, the etiological agent of porcine enzootic pneumonia (PEP. The recombinant antigen (HSP70212-600, previously shown as immunogenic in formulation with classic adjuvants, was used to immunize BALB/c mice in combination with SBa-15 or SBa-16 MSNs, and the effects obtained with these formulations were compared to those obtained with alum, the adjuvant traditionally used in anti-PEP bacterins. The HSP70212-600 + SBa-15 vaccine elicited a strong humoral immune response, with high serum total IgG levels, comparable to those obtained using HSP70212-600 + alum. The HSP70212-600 + SBa-16 vaccine elicited a moderate humoral immune response, with lower levels of total IgG. The cellular immune response was assessed by the detection of IFN-γ, IL-4 and IL-10 in splenocyte culture supernatants. The HSP70212-600 + SBa-15 vaccine increased IFN-γ, IL-4 and IL-10 levels, while no stimulation was detected with the HSP70212-600 + SBa-16 vaccine. The HSP70212-600 + SBa-15 vaccine induced a mixed Th1/Th2-type response, with an additional IL-10 mediated anti-inflammatory effect, both of relevance for an anti-PEP vaccine. Alum adjuvant controls stimulated an unspecific cellular immune response, with similar levels of cytokines detected in mice immunized either with HSP70212-600 + alum or with the adjuvant alone. The better humoral and cellular immune responses elicited in mice indicated that SBa-15 has adjuvant potential, and can be considered as an alternative to the use of alum in veterinary vaccines. The use of SBa-15 with HSP70212-600 is also promising as a potential anti-PEP subunit vaccine formulation.

  17. Genetic Recombination

    Science.gov (United States)

    Whitehouse, H. L. K.

    1973-01-01

    Discusses the mechanisms of genetic recombination with particular emphasis on the study of the fungus Sordaria brevicollis. The study of recombination is facilitated by the use of mutants of this fungus in which the color of the ascospores is affected. (JR)

  18. Production of barley endoprotease B2 in Pichia pastoris and its proteolytic activity against native and recombinant hordeins

    DEFF Research Database (Denmark)

    Rosenkilde, Anne Lind; Dionisio, Giuseppe; Holm, Preben Bach

    2014-01-01

    -terminal truncated version (HvEPB2ΔC) and a proteolytic resistant His6 tag. Maximum yield was obtained after 4 days of induction. Recombinant HvEPB2ΔC (r-HvEPB2ΔC) was purified using a single step of Ni2+-affinity chromatography. Purified protein was evaluated by SDS–PAGE, Western blotting and activity assays...... was 60 °C, thermal stability T50 value was 44 °C and the pH optimum was 4.5. r-HvEPB2ΔC was incubated with native purified barley seed storage proteins for up to 48 h. After 12 h, r-HvEPB2ΔC efficiently reduced the C and D hordeins almost completely, as evaluated by SDS–PAGE. The intensities of the B...... and γ hordein bands decreased continuously over the 48 h. No degradation occurred in the presence of E64. Recombinant hordeins (B1, B3 and γ1) were expressed in Escherichia coli. After 2 h of incubation with r-HvEPB2ΔC, an almost complete degradation of γ1 and partial digests of hordein B1 and B3 were...

  19. Expression of recombinant staphylokinase, a fibrin-specific plasminogen activator of bacterial origin, in potato (Solanum tuberosum L.) plants.

    Science.gov (United States)

    Gerszberg, Aneta; Wiktorek-Smagur, Aneta; Hnatuszko-Konka, Katarzyna; Łuchniak, Piotr; Kononowicz, Andrzej K

    2012-03-01

    One of the most dynamically developing sectors of green biotechnology is molecular farming using transgenic plants as natural bioreactors for the large scale production of recombinant proteins with biopharmaceutical and therapeutic values. Such properties are characteristic of certain proteins of bacterial origin, including staphylokinase. For many years, work has been carried out on the use of this protein in thrombolytic therapy. In this study, transgenic Solanum tuberosum plants expressing a CaMV::sak-mgpf-gusA gene fusion, were obtained. AGL1 A. tumefaciens strain was used in the process of transformation. The presence of the staphylokinase gene was confirmed by PCR in 22.5% of the investigated plants. The expression of the fusion transgene was detected using the β-glucuronidase activity assay in 32 putative transgenic plants. Furthermore, on the basis of the GUS histochemical reaction, the transgene expression pattern had a strong, constitutive character in seven of the transformants. The polyacrylamide gel electrophoresis of a protein extract from the SAK/PCR-positive plants, revealed the presence of a119 kDa protein that corresponds to that of the fusion protein SAK-mGFP-GUSA. Western blot analysis, using an antibody against staphylokinase, showed the presence of the staphylokinase domain in the 119 kDa protein in six analyzed transformants. However, the enzymatic test revealed amidolytic activity characteristic of staphylokinase in the protein extract of only one plant. This is the first report on a Solanum tuberosum plant producing a recombinant staphylokinase protein, a plasminogen activator of bacterial origin.

  20. Recombinant mouse PAP has pH-dependent ectonucleotidase activity and acts through A(1-adenosine receptors to mediate antinociception.

    Directory of Open Access Journals (Sweden)

    Nathaniel A Sowa

    Full Text Available Prostatic acid phosphatase (PAP is expressed in nociceptive neurons and functions as an ectonucleotidase. When injected intraspinally, the secretory isoforms of human and bovine PAP protein have potent and long-lasting antinociceptive effects that are dependent on A(1-adenosine receptor (A(1R activation. In this study, we purified the secretory isoform of mouse (mPAP using the baculovirus expression system to determine if recombinant mPAP also had antinociceptive properties. We found that mPAP dephosphorylated AMP, and to a much lesser extent, ADP at neutral pH (pH 7.0. In contrast, mPAP dephosphorylated all purine nucleotides (AMP, ADP, ATP at an acidic pH (pH 5.6. The transmembrane isoform of mPAP had similar pH-dependent ectonucleotidase activity. A single intraspinal injection of mPAP protein had long-lasting (three day antinociceptive properties, including antihyperalgesic and antiallodynic effects in the Complete Freund's Adjuvant (CFA inflammatory pain model. These antinociceptive effects were transiently blocked by the A(1R antagonist 8-cyclopentyl-1, 3-dipropylxanthine (CPX, suggesting mPAP dephosphorylates nucleotides to adenosine to mediate antinociception just like human and bovine PAP. Our studies indicate that PAP has species-conserved antinociceptive effects and has pH-dependent ectonucleotidase activity. The ability to metabolize nucleotides in a pH-dependent manner could be relevant to conditions like inflammation where tissue acidosis and nucleotide release occur. Lastly, our studies demonstrate that recombinant PAP protein can be used to treat chronic pain in animal models.

  1. Cultured Mast Cells from Patients with Asthma and Controls Respond with Similar Sensitivity to Recombinant Der P2-Induced, IgE-Mediated Activation

    DEFF Research Database (Denmark)

    Krohn, I K; Sverrild, A; Lund, G

    2013-01-01

    for mite allergen Der p2. The sensitivity of IgE-mediated activation of mast cells was investigated as FcεRI-mediated upregulation of CD63. Ten subjects were atopic, defined as a positive skin prick test (>3 mm) to at least one of ten common allergens. After activation with recombinant Der p2, the maximum...

  2. Absorption/desorption in sprays

    International Nuclear Information System (INIS)

    Naimpally, A.

    1987-01-01

    This survey paper shall seek to present the present state of knowledge concerning absorption and desorption in spray chambers. The first part of the paper presents the theories and formulas for the atomization and break-up of sprays in nozzles. Formulas for the average (sauter-mean) diameters are then presented. For the case of absorption processes, the formulas for the dimensionless mass transfer coefficients is in drops. The total; mass transfer is the total of the transfer in individual drops. For the case of desorption of sparingly soluble gases from liquids in a spray chamber, the mass transfer occurs in the spray just at the point of break-up of the jet. Formulas for the desorption of gases are presented

  3. Application of synchrotron-radiation-based x-ray microprobe techniques for the analysis of recombination activity of metals precipitated at Si/SiGe misfit dislocations

    CERN Document Server

    Vyvenko, O F; Istratov, A A; Weber, E R; Kittler, M; Seifert, W

    2002-01-01

    In this study we report application of synchrotron-radiation-based x-ray microprobe techniques (the x-ray-beam-induced current (XBIC) and x-ray fluorescence (mu-XRF) methods) to the analysis of the recombination activity and space distribution of copper and iron in the vicinity of dislocations in silicon/silicon-germanium structures. A combination of these two techniques enables one to study the chemical nature of the defects and impurities and their recombination activity in situ and to map metal clusters with a micron-scale resolution. XRF analysis revealed that copper formed clearly distinguishable precipitates along the misfit dislocations. A proportional dependence between the XBIC contrast and the number of copper atoms in the precipitates was established. In hydrogen-passivated iron-contaminated samples we observed clusters of iron precipitates which had no recombination activity detectable by the XBIC technique as well as iron clusters which were not completely passivated.

  4. Recombinant Nox4 cytosolic domain produced by a cell or cell-free base systems exhibits constitutive diaphorase activity

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Minh Vu Chuong, E-mail: mvchuong@yahoo.fr [GREPI AGIM FRE 3405 CNRS-UJF, Universite Joseph Fourier, Grenoble (France); Zhang, Leilei [GREPI AGIM FRE 3405 CNRS-UJF, Universite Joseph Fourier, Grenoble (France); Lhomme, Stanislas; Mouz, Nicolas [PX' Therapeutics, MINATEC/Batiment de Haute Technologie, Grenoble (France); Lenormand, Jean-Luc [HumProTher Laboratory, TheReX/TIMC-IMAG UMR 5525 CNRS UJF, Universite Joseph Fourier, UFR de Medecine, Domaine de la Merci, 38706 La Tronche (France); Lardy, Bernard; Morel, Francoise [GREPI AGIM FRE 3405 CNRS-UJF, Universite Joseph Fourier, Grenoble (France)

    2012-03-16

    Highlights: Black-Right-Pointing-Pointer A comparison of two bacterial cell and cell-free protein expression systems is presented. Black-Right-Pointing-Pointer Soluble and active truncated Nox4 proteins are produced. Black-Right-Pointing-Pointer Nox4 has a constitutive diaphorase activity which is independent of cytosolic factors. Black-Right-Pointing-Pointer Isoform Nox4B is unable to initiate the first electronic transfer step. Black-Right-Pointing-Pointer Findings contribute to the understanding of the mechanism of Nox4 oxidase activity. -- Abstract: The membrane protein NADPH (nicotinamide adenine dinucleotide phosphate) oxidase Nox4 constitutively generates reactive oxygen species differing from other NADPH oxidases activity, particularly in Nox2 which needs a stimulus to be active. Although the precise mechanism of production of reactive oxygen species by Nox2 is well characterized, the electronic transfer throughout Nox4 remains unclear. Our study aims to investigate the initial electronic transfer step (diaphorase activity) of the cytosolic tail of Nox4. For this purpose, we developed two different approaches to produce soluble and active truncated Nox4 proteins. We synthesized soluble recombinant proteins either by in vitro translation or by bacteria induction. While proteins obtained by bacteria induction demonstrate an activity of 4.4 {+-} 1.7 nmol/min/nmol when measured against iodonitro tetrazolium chloride and 20.5 {+-} 2.8 nmol/min/nmol with cytochrome c, the soluble proteins produced by cell-free expression system exhibit a diaphorase activity with a turn-over of 26 {+-} 2.6 nmol/min/nmol when measured against iodonitro tetrazolium chloride and 48 {+-} 20.2 nmol/min/nmol with cytochrome c. Furthermore, the activity of the soluble proteins is constitutive and does not need any stimulus. We also show that the cytosolic tail of the isoform Nox4B lacking the first NADPH binding site is unable to demonstrate any diaphorase activity pointing out the

  5. Anti-tumor efficacy of lymphokine-activated killer cells and recombinant interleukin 2 in vivo

    International Nuclear Information System (INIS)

    Mule, J.J.; Shu, S.; Rosenberg, S.A.

    1985-01-01

    The authors showed previously that adoptive immunotherapy with the combination of LAK cells and recombinant IL 2 (RIL 2) can markedly reduce pulmonary micrometastases from multiple sarcomas established 3 days after the i.v. injection of syngeneic tumor cells in C57BL/6 mice. In this report, they analyzed the factors required for successful therapy. Titration analysis in vivo revealed an inverse relationship between the number of pulmonary metastases remaining after treatment and both the number of LAK cells and the amount of RIL 2 administered. Fresh or unstimulated splenocytes had no anti-tumor effect; a 2- to 3-day incubation of splenocytes in RIL 2 was required. LAK cells generated from allogeneic DBA (H-2d) splenocytes were as effective in vivo as syngeneic, C57BL/6 (H-2b) LAK cells. The anti-metastatic capacity of LAK cells was significantly reduced or eliminated when irradiated with 3000 rad before adoptive transfer. The combined therapy of LAK cells plus RIL 2 was shown to be highly effective in mice immunosuppressed by 500 rad total body irradiation and in treating macrometastases established in the lung 10 days after the i.v. injection of sarcoma cells. Further, reduction of both micrometastases and macrometastases could also be achieved by RIL 2 alone when administered at higher levels than were required with LAK cells. The value of LAK cell transfer and of IL 2 administration for the treatment of tumors established at other sites is currently under investigation

  6. Data compilation for particle impact desorption

    International Nuclear Information System (INIS)

    Oshiyama, Takashi; Nagai, Siro; Ozawa, Kunio; Takeuchi, Fujio.

    1984-05-01

    The desorption of gases from solid surfaces by incident electrons, ions and photons is one of the important processes of hydrogen recycling in the controlled thermonuclear reactors. We have surveyed the literature concerning the particle impact desorption published through 1983 and compiled the data on the desorption cross sections and desorption yields with the aid of a computer. This report presents the results obtained for electron stimulated desorption, the desorption cross sections and yields being given in graphs and tables as functions of incident electron energy, surface temperature and gas exposure. (author)

  7. Immunoregulatory activities of human immunodeficiency virus (HIV) proteins: Effect of HIV recombinant and synthetic peptides on immunoglobulin synthesis and proliferative responses by normal lymphocytes

    International Nuclear Information System (INIS)

    Nair, M.P.N.; Pottathil, R.; Heimer, E.P.; Schwartz, S.A.

    1988-01-01

    Recombinant and synthetic peptides corresponding to envelope proteins of the human immunodeficiency virus (HIV) were examined for their effects on the activities of lymphocytes from normal donors in vitro. Although lymphocytes cultured with env-gag peptides produced significant amounts of IgG, addition of env-gag peptides to a pokeweed mitogen-induced B-cell activation system resulted in suppression of immunoglobulin synthesis by normal lymphocytes. Recombinant antigens, env-gag and env-80 dihydrofolate reductase (DHFR), produced a substantial proliferative response by peripheral blood mononuclear cells (PBMC) as determined by [ 3 H]thymidine incorporation. PBMC precultured with HIV synthetic peptide env 578-608 also manifested significant proliferative responses as compared to control cultures. CD3 + lymphocytes precultured with recombinant HIV antigens, env-gag and env-80 DHFR, and synthetic HIV peptide, env 487-511, showed moderate but significant proliferative responses. Both recombinant antigens and synthetic peptides also produced a dose-dependent stimulatory effect on proliferation by CD3 - lymphocytes. These studies demonstrate that recombinant and synthetic peptides of the HIV genome express immunoregulatory T- and B-cell epitopes. Identification of unique HIV epitopes with immunogenic and immunoregulatory activities is necessary for the development of an effective vaccine against HIV infection

  8. Activity in mice of recombinant BCG-EgG1Y162 vaccine for Echinococcus granulosus infection.

    Science.gov (United States)

    Ma, Xiumin; Zhao, Hui; Zhang, Fengbo; Zhu, Yuejie; Peng, Shanshan; Ma, Haimei; Cao, Chunbao; Xin, Yan; Yimiti, Delixiati; Wen, Hao; Ding, Jianbing

    2016-01-01

    Cystic hydatid disease is a zoonotic parasitic disease caused by Echinococcus granulosus which is distributed worldwide. The disease is difficult to treat with surgery removal is the only cure treatment. In the high endemic areas, vaccination of humans is believed a way to protect communities from the disease. In this study we vaccinated BALB/c mice with rBCG-EgG1Y162, and then detected the level of IgG and IgE specifically against the recombinant protein by ELISA, rBCG-EgG1Y162 induced strong and specific cellular and humoral immune responses. In vitro study showed that rBCG-EgG1Y162 vaccine not only promote splenocytes proliferation but also active T cell. In addition, the rBCG-EgG1Y162 induced a protection in the mice against secondary infection of Echinococcus granulosus.

  9. Cryopreserved recombinant tissue plasminogen activator for the restoration of occluded central venous access devices in pediatric oncology patients

    International Nuclear Information System (INIS)

    Iqbal, Y.; Al-Katheri, A.; Al-Sedairy, R.; Al-Omari, A.; Abdullah, Mohammed F.; Crankson, S.

    2002-01-01

    Thrombolytic therapy with urokinase 5000 units has been the standard therapy for restoration of thrombosed central catheters. However, with the decreased availability of urokinase, alternatives needed to be sought. The aim of the study was to determine the efficacy, bioactivity, dwell time and cost of cryopreserved recombinant tissue plasminogen activator (rTPA) in the restoration of occluded central venous access devices. For children 10kg, a dose of 1 mg was used. The dwell time was 1-2 hours. Of the 40 courses of rTPA, 39 fully restored central venous line patency (97%). Successful courses were instilled for an average of 1 hour. Cryopreserved rTPA appears to be safe and effective in the dose used to restore the patency of occluded central venous access devices in pediatric oncology patients. (author)

  10. A comparison between recombinant activated factor VII (Aryoseven) and Novoseven in patients with congenital factor VII deficiency.

    Science.gov (United States)

    Faranoush, M; Abolghasemi, Hassan; Toogeh, Gh; Karimi, M; Eshghi, P; Managhchi, M; Hoorfar, H; Dehdezi, B Keikhaei; Mehrvar, A; Khoeiny, B; Kamyar, K; Heshmat, R; Baghaeipour, M R; Mirbehbahani, N B; Fayazfar, R; Ahmadinejad, M; Naderi, M

    2015-11-01

    In order to establish the efficacy and biosimilar nature of AryoSeven to NovoSeven in the treatment of congenital factor VII (FVII) deficiency, patients received either agent at 30 μg/kg, intravenously per week for 4 weeks, in a randomized fashion. The primary aim was to compare FVII:coagulation activity (FVII:C), 20 minutes after recombinant activated FVII (rFVIIa) injection, in the 2 groups. A secondary measure was self-reported bleeding. The median interquartile baseline range of the plasma level of activated FVII (FVIIa) activity in the 2 groups was 1.6 (1.1-14.0) IU/dL and 5.0 (1.1-25.5) IU/dL. All patients achieved levels of FVIIa (FVII:C) >30 IU/dL, 20 minutes after the injection of rFVIIa. Bleeding was similar between the 2 groups, with a comparable decrease in severity and frequency compared to the last month prior to treatment. AryoSeven is similar to NovoSeven in increasing postinjection FVIIa activity as well as in clinical safety and efficacy. © The Author(s) 2014.

  11. EFFECT OF RECOMBINANT TISSUE-PLASMINOGEN ACTIVATOR ON INTRAABDOMINAL ABSCESS FORMATION IN RATS WITH GENERALIZED PERITONITIS

    NARCIS (Netherlands)

    van Goor, Harry; de Graaf, JS; Kooi, K; Sluiter, WJ; Bom, VJJ; van der Meer, J; Bleichrodt, RP

    1994-01-01

    BACKGROUND: During generalized peritonitis, intraabdominal fibrin deposition is stimulated whereas fibrinolytic activity is reduced, which predisposes intra-abdominal abscess formation. We investigated the effects of increasing the intra-abdominal fibrinolytic activity on abscess formation by

  12. Desorption Kinetics and Mechanisms of CO2 on Amine-Based Mesoporous Silica Materials

    Directory of Open Access Journals (Sweden)

    Yang Teng

    2017-01-01

    Full Text Available Tetraethylenepentamine (TEPA-based mesoporous MCM-41 is used as the adsorbent to determine the CO2 desorption kinetics of amine-modified materials after adsorption. The experimental data of CO2 desorption as a function of time are derived by zero-length column at different temperatures (35, 50, and 70 °C and analyzed by Avrami’s fractional-order kinetic model. A new method is used to distinguish the physical desorption and chemical desorption performance of surface-modified mesoporous MCM-41. The activation energy Ea of CO2 physical desorption and chemical desorption calculated from Arrhenius equation are 15.86 kJ/mol and 57.15 kJ/mol, respectively. Furthermore, intraparticle diffusion and Boyd’s film models are selected to investigate the mechanism of CO2 desorption from MCM-41 and surface-modified MCM-41. For MCM-41, there are three rate-limiting steps during the desorption process. Film diffusion is more prominent for the CO2 desorption rates at low temperatures, and pore diffusion mainly governs the rate-limiting process under higher temperatures. Besides the surface reaction, the desorption process contains four rate-limiting steps on surface-modified MCM-41.

  13. Impact of cysteine variants on the structure, activity, and stability of recombinant human α-galactosidase A

    Science.gov (United States)

    Qiu, Huawei; Honey, Denise M; Kingsbury, Jonathan S; Park, Anna; Boudanova, Ekaterina; Wei, Ronnie R; Pan, Clark Q; Edmunds, Tim

    2015-01-01

    Recombinant human α-galactosidase A (rhαGal) is a homodimeric glycoprotein deficient in Fabry disease, a lysosomal storage disorder. In this study, each cysteine residue in rhαGal was replaced with serine to understand the role each cysteine plays in the enzyme structure, function, and stability. Conditioned media from transfected HEK293 cells were assayed for rhαGal expression and enzymatic activity. Activity was only detected in the wild type control and in mutants substituting the free cysteine residues (C90S, C174S, and the C90S/C174S). Cysteine-to-serine substitutions at the other sites lead to the loss of expression and/or activity, consistent with their involvement in the disulfide bonds found in the crystal structure. Purification and further characterization confirmed that the C90S, C174S, and the C90S/C174S mutants are enzymatically active, structurally intact and thermodynamically stable as measured by circular dichroism and thermal denaturation. The purified inactive C142S mutant appeared to have lost part of its alpha-helix secondary structure and had a lower apparent melting temperature. Saturation mutagenesis study on Cys90 and Cys174 resulted in partial loss of activity for Cys174 mutants but multiple mutants at Cys90 with up to 87% higher enzymatic activity (C90T) compared to wild type, suggesting that the two free cysteines play differential roles and that the activity of the enzyme can be modulated by side chain interactions of the free Cys residues. These results enhanced our understanding of rhαGal structure and function, particularly the critical roles that cysteines play in structure, stability, and enzymatic activity. PMID:26044846

  14. SPS Ion Induced Desorption Experiment

    CERN Multimedia

    Maximilien Brice

    2003-01-01

    This experiment will give a study about the induced desorption from heavy ion (Indium ion run from week 45 in SPS T4-H8 area) impacting LHC type graphite collimator. 4 different samples are located in the 4 chambers 90° one to each other: pure graphite, graphite with copper coating, graphite with NEG coating, 316LN stainless steal (reference).

  15. Study of defects near molybdenum surface using thermal desorption spectrometer

    International Nuclear Information System (INIS)

    Naik, P.K.

    1980-01-01

    Thermal desorption spectrometry is utilized to study the migration of atoms and defects near molybdenum surface. The thermal desorption spectra of inert gas ions (neon, argon and krypton) injected with various energies (430-1950 eV) into a polycrystalline molybdenum target with various dosages (6.4 x 10sup(12) - 3.9 x 10sup(14) ions/cmsup(2)) are investigated. Four different states of binding of the trapped atoms corresponding to the activation energies for desorption have been revealed from the spectra. The activation energies are found to be relatively insensitive to the species of the bombarding ion, incident ion energy and the dosage. The patterns of the spectra are strongly influenced by the mean projected range of the ions into the solid. The activation energies deduced are in good agreement with those reported for the migration of atoms and defects in molybdenum. (auth.)

  16. Adsorption and desorption of radioactive inert gases in various materials

    International Nuclear Information System (INIS)

    Butkus, D.

    1999-01-01

    Peculiarities of the 85 Kr and 133 Xe adsorption and desorption processes in active carbon and paraffin are considered in the work. During the desorption process, the distribution of 85 Kr and 133 Xe atoms in active carbon particles is uneven: atoms in narrow micropores desorb the last. It is shown that by changing adsorption conditions the presence time of radioactive inert gases in an active carbon can be prolonged. The adsorption and desorption processes change in the adsorbent, which changes its aggregation state: adsorption occurs in a liquid absorbent and desorption - in a solid absorbent. Paraffin is just such an absorbent changing its aggregation state with low energy losses. It has been obtained that 133 Xe accumulates less in liquid paraffin that in an active carbon. The absorption of 85 Kr in paraffin is larger than in an active carbon (at 18-20 degrees Celsius), while desorption is slower. The velocity of radioactive inert gas atom motion in different places of a solid paraffin sample is different - it increases approaching the borders of the sample. Prolongation of the desorption time of radioactive inert gases from adsorbents and adsorbents in many cases is of a practical importance. In this work, it has been shown by model experiments that the intensity of adsorption and desorption processes for the same sorbents can be changed. Desorption intensity changes are related to the distribution of gas atoms on the surface of particles and in micropores. Desorption velocity decreases if inert gas atoms having entered micropores are 'closed' by condensed liquids in the environment. In this case an inert gas atom diffuses within the whole particle volume or through the condensed liquid. Radioactive inert gases 85 Kr and 133 Xe are absorbed not only in liquid paraffin but in solid one as well. Therefore, after a paraffin sample is hermetically closed in a glass dish, 85 Kr (gas) having diffused from this sample is repeatedly absorbed in it. The 85 Kr

  17. Antiviral cationic peptides as a strategy for innovation in global health therapeutics for dengue virus: high yield production of the biologically active recombinant plectasin peptide.

    Science.gov (United States)

    Rothan, Hussin A; Mohamed, Zulqarnain; Suhaeb, Abdulrazzaq M; Rahman, Noorsaadah Abd; Yusof, Rohana

    2013-11-01

    Dengue virus infects millions of people worldwide, and there is no vaccine or anti-dengue therapeutic available. Antimicrobial peptides have been shown to possess effective antiviral activity against various viruses. One of the main limitations of developing these peptides as potent antiviral drugs is the high cost of production. In this study, high yield production of biologically active plectasin peptide was inexpensively achieved by producing tandem plectasin peptides as inclusion bodies in E. coli. Antiviral activity of the recombinant peptide towards dengue serotype-2 NS2B-NS3 protease (DENV2 NS2B-NS3pro) was assessed as a target to inhibit dengue virus replication in Vero cells. Single units of recombinant plectasin were collected after applying consecutive steps of refolding, cleaving by Factor Xa, and nickel column purification to obtain recombinant proteins of high purity. The maximal nontoxic dose (MNTD) of the recombinant peptide against Vero cells was 20 μM (100 μg/mL). The reaction velocity of DENV2 NS2B-NS3pro decreased significantly after increasing concentrations of recombinant plectasin were applied to the reaction mixture. Plectasin peptide noncompetitively inhibited DENV2 NS2B-NS3pro at Ki value of 5.03 ± 0.98 μM. The percentage of viral inhibition was more than 80% at the MNTD value of plectasin. In this study, biologically active recombinant plectasin which was able to inhibit dengue protease and viral replication in Vero cells was successfully produced in E. coli in a time- and cost- effective method. These findings are potentially important in the development of potent therapeutics against dengue infection.

  18. Recombinant deamidated mutants of Erwinia chrysanthemi L-asparaginase have similar or increased activity compared to wild-type enzyme.

    Science.gov (United States)

    Gervais, David; Foote, Nicholas

    2014-10-01

    The enzyme Erwinia chrysanthemi L-asparaginase (ErA) is an important biopharmaceutical product used in the treatment of acute lymphoblastic leukaemia. Like all proteins, certain asparagine (Asn) residues of ErA are susceptible to deamidation to aspartic acid (Asp), which may be a concern with respect to enzyme activity and potentially to pharmaceutical efficacy. Recombinant ErA mutants containing Asn to Asp changes were expressed, purified and characterised. Two mutants with single deamidation sites (N41D and N281D) were found to have approximately the same specific activity (1,062 and 924 U/mg, respectively) as the wild-type (908 U/mg). However, a double mutant (N41D N281D) had an increased specific activity (1261 U/mg). The N41D mutation conferred a slight increase in the catalytic constant (k cat 657 s(-1)) when compared to the WT (k cat 565 s(-1)), which was further increased in the double mutant, with a k cat of 798 s(-1). Structural analyses showed that the slight changes caused by point mutation of Asn41 to Asp may have reduced the number of hydrogen bonds in this α-helical part of the protein structure, resulting in subtle changes in enzyme turnover, both structurally and catalytically. The increased α-helical content observed with the N41D mutation by circular dichroism spectroscopy correlates with the difference in k cat, but not K m. The N281D mutation resulted in a lower glutaminase activity compared with WT and the N41D mutant, however the N281D mutation also imparted less stability to the enzyme at elevated temperatures. Taken as a whole, these data suggest that ErA deamidation at the Asn41 and Asn281 sites does not affect enzyme activity and should not be a concern during processing, storage or clinical use. The production of recombinant deamidated variants has proven an effective and powerful means of studying the effect of these changes and may be a useful strategy for other biopharmaceutical products.

  19. Construction of recombinant adenovirus with Egr-1 promoter and Smad7 cDNA and study of the Egr-1 promoter's biological activity

    International Nuclear Information System (INIS)

    Cai Xuwei; Fu Xiaolong; Yang Jian; Song Houyan

    2005-01-01

    Objective: To construct a recombinant replication-defective adenovirus containing Egr-1 promoter and Smad7 cDNA, then to evaluate the biological activity of Egr-1 promoter. Methods: Based on Adeno- X TM expression system, CMV promoter of the pShuttle vector was replaced by Egr-1 promoter, and the Smad7 cDNA was subcloned into the MCS(multiple cloning site) of pShuttle. The recombinant pShuttle was then sub-cloned into the Adeno-X TM genome, which was transformed into E. coli to get recombinant Adeno-X TM plasmid DNA. The recombinant adenovirus was packaged and amplified in the transfected HEK293 cells before it was purified and tested for viral titer. The fibroblasts (3T6 cells) infected by the recombinant adenovirus were irradiated , and the activity of Egr-1 promoter was quantitively determined by the amount of Smad7 protein expressed in the 3T6 cells using Western blot. Results: Identified by restriction endonuclease analysis and PCR, the recombinant adenovirus containing Egr-1 promoter and Smad7 cDNA was constructed successfully, with a viral titer of 1.0 x 10 11 TCID 50 /ml. The expressed amount of Smad7 protein varied at different dose levels and different time points post-irradiation in the 3T6 cells infected with the recombinant adenovirus. The amount of Smad7 protein increased along with the rising of the irradiation dose, and remained at a high expression level from 8 Gy to 15 Gy. The amount of Smad7 protein started to increase at 2 hours post-irradiation, and maintained a relatively high level for the next 5 hours before it descended, which was not observed in the control 3T6 cells. Conclusions: With the aid of Adeno-X TM expression system and molecular cloning techniques, construction of recombinant adenovirus could be quick and efficient. The recombined Egr-1 promoter has the activity of regulating the expression of downstream Smad7 cDNA. The increase in Smad7 expression under control of Egr-1 promoter induced by ionizing radiation is time- and dose

  20. Instant screening and verification of carbapenemase activity in Bacteroides fragilis in positive blood culture, using matrix-assisted laser desorption ionization--time of flight mass spectrometry.

    Science.gov (United States)

    Johansson, Åsa; Nagy, Elisabeth; Sóki, József

    2014-08-01

    Rapid identification of isolates in positive blood cultures are of great importance to secure correct treatment of septicaemic patients. As antimicrobial resistance is increasing, rapid detection of resistance is crucial. Carbapenem resistance in Bacteroides fragilis associated with cfiA-encoded class B metallo-beta-lactamase is emerging. In our study we spiked blood culture bottles with 26 B. fragilis strains with various cfiA-status and ertapenem MICs. By using main spectra specific for cfiA-positive and cfiA-negative B. fragilis strains, isolates could be screened for resistance. To verify strains that were positive in the screening, a carbapenemase assay was performed where the specific peaks of intact and hydrolysed ertapenem were analysed with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). We show here that it is possible to correctly identify B. fragilis and to screen for enzymic carbapenem resistance directly from the pellet of positive blood cultures. The carbapenemase assay to verify the presence of the enzyme was successfully performed on the pellet from the direct identification despite the presence of blood components. The result of the procedure was achieved in 3 h. Also the Bruker mass spectrometric β-lactamase assay (MSBL assay) prototype software was proven not only to be based on an algorithm that correlated with the manual inspection of the spectra, but also to improve the interpretation by showing the variation in the dataset. © 2014 The Authors.

  1. Matrix-assisted laser desorption ionisation time-of-flight mass spectrometry rapid detection of carbapenamase activity in Acinetobacter baumannii isolates

    Directory of Open Access Journals (Sweden)

    Noha Abouseada

    2017-01-01

    Full Text Available Introduction: Carbapenamase-producing Acinetobacter baumannii are an increasing threat in hospitals and Intensive Care Units. Accurate and rapid detection of carbapenamase producers has a great impact on patient improvement and aids in implementation of infection control measures. Aim: In this study, we describe the use of matrix-assisted laser desorption ionisation time-of-flight mass spectrometry (MALDI TOF MS to identify carbapenamase-producing A. baumannii isolates in up to 3 h. Isolates and Methods: A total of 50 A. baumannii isolates (of which 39 were carabapenamase producers were tested using MALDI TOF MS. Isolates were incubated for 3 h with 0.25 mg/ml up to 2 mg/ml of imipenem (IMP at 37°C. Supernatants were analysed by MALDI TOF to analyse peaks corresponding to IMP (300 Da and an IMP metabolite (254 Da using UltrafleXtreme (Bruker Daltonics, Bremen, Germany. Results: All carbapenamase-producing isolates were evidenced by the disappearance or reduction in intensity of the 300 Da peak of IPM and the appearance of a 254 Da peak of the IPM metabolite. In isolates that did not produce carbapenamase, the IPM 300 Da peak remained intact. Conclusion: MALDI TOF is a promising tool in the field of diagnostic microbiology that has the ability to transfer identification and antimicrobial susceptibility testing time from days to hours.

  2. 78 FR 12074 - Office of Biotechnology Activities; Recombinant DNA Research: Actions Under the NIH Guidelines...

    Science.gov (United States)

    2013-02-21

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... recommendations of the RAC, the NIH Office of Biotechnology Activities (OBA) concluded that more specific guidance... address or by fax at 301-496-9839 or by mail to the Office of Biotechnology Activities, National...

  3. 76 FR 62816 - Office of Biotechnology Activities; Recombinant DNA Research: Action Under the NIH Guidelines for...

    Science.gov (United States)

    2011-10-11

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology.... SUMMARY: The Office of Biotechnology Activities (OBA) is updating Appendix B of the NIH Guidelines to... Biotechnology Activities, National Institutes of Health. [FR Doc. 2011-26224 Filed 10-7-11; 8:45 am] BILLING...

  4. 76 FR 3150 - Office of Biotechnology Activities; Recombinant DNA Research: Action Under the NIH Guidelines for...

    Science.gov (United States)

    2011-01-19

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... rodent). On July 20, 2010 the NIH Office of Biotechnology Activities (OBA) published a proposed action... Biotechnology Activities, National Institutes of Health, 6705 Rockledge Drive, Suite 750, MSC 7985, Bethesda...

  5. 75 FR 28811 - Office of Biotechnology Activities; Recombinant DNA Research: Proposed Actions Under the NIH...

    Science.gov (United States)

    2010-05-24

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... Yersinia pestis has been submitted to the NIH Office of Biotechnology Activities (OBA) by the Institutional... Biotechnology Activities, National Institutes of Health. [FR Doc. 2010-12453 Filed 5-21-10; 8:45 am] BILLING...

  6. Activation of Recombinantly Expressed l-Amino Acid Oxidase from Rhizoctonia solani by Sodium Dodecyl Sulfate

    Directory of Open Access Journals (Sweden)

    Katharina Hahn

    2017-12-01

    Full Text Available l-Amino acid oxidases (l-AAO catalyze the oxidative deamination of l-amino acids to the corresponding α-keto acids. The non-covalently bound cofactor FAD is reoxidized by oxygen under formation of hydrogen peroxide. We expressed an active l-AAO from the fungus Rhizoctonia solani as a fusion protein in E. coli. Treatment with small amounts of the detergent sodium dodecyl sulfate (SDS stimulated the activity of the enzyme strongly. Here, we investigated whether other detergents and amphiphilic molecules activate 9His-rsLAAO1. We found that 9His-rsLAAO1 was also activated by sodium tetradecyl sulfate. Other detergents and fatty acids were not effective. Moreover, effects of SDS on the oligomerization state and the protein structure were analyzed. Native and SDS-activated 9His-rsLAAO1 behaved as dimers by size-exclusion chromatography. SDS treatment induced an increase in hydrodynamic radius as observed by size-exclusion chromatography and dynamic light scattering. The activated enzyme showed accelerated thermal inactivation and an exposure of additional protease sites. Changes in tryptophan fluorescence point to a more hydrophilic environment. Moreover, FAD fluorescence increased and a lower concentration of sulfites was sufficient to form adducts with FAD. Taken together, these data point towards a more open conformation of SDS-activated l-amino acid oxidase facilitating access to the active site.

  7. Identifying Effective Enzyme Activity Targets for Recombinant Class I and Class II Collagenase for Successful Human Islet Isolation.

    Science.gov (United States)

    Balamurugan, Appakalai N; Green, Michael L; Breite, Andrew G; Loganathan, Gopalakrishnan; Wilhelm, Joshua J; Tweed, Benjamin; Vargova, Lenka; Lockridge, Amber; Kuriti, Manikya; Hughes, Michael G; Williams, Stuart K; Hering, Bernhard J; Dwulet, Francis E; McCarthy, Robert C

    2016-01-01

    Isolation following a good manufacturing practice-compliant, human islet product requires development of a robust islet isolation procedure where effective limits of key reagents are known. The enzymes used for islet isolation are critical but little is known about the doses of class I and class II collagenase required for successful islet isolation. We used a factorial approach to evaluate the effect of high and low target activities of recombinant class I (rC1) and class II (rC2) collagenase on human islet yield. Consequently, 4 different enzyme formulations with divergent C1:C2 collagenase mass ratios were assessed, each supplemented with the same dose of neutral protease. Both split pancreas and whole pancreas models were used to test enzyme targets (n = 20). Islet yield/g pancreas was compared with historical enzymes (n = 42). Varying the Wunsch (rC2) and collagen degradation activity (CDA, rC1) target dose, and consequently the C1:C2 mass ratio, had no significant effect on tissue digestion. Digestions using higher doses of Wunsch and CDA resulted in comparable islet yields to those obtained with 60% and 50% of those activities, respectively. Factorial analysis revealed no significant main effect of Wunsch activity or CDA for any parameter measured. Aggregate results from 4 different collagenase formulations gave 44% higher islet yield (>5000 islet equivalents/g) in the body/tail of the pancreas (n = 12) when compared with those from the same segment using a standard natural collagenase/protease mixture (n = 6). Additionally, islet yields greater than 5000 islet equivalents/g pancreas were also obtained in whole human pancreas. A broader C1:C2 ratio can be used for human islet isolation than has been used in the past. Recombinant collagenase is an effective replacement for the natural enzyme and we have determined that high islet yield can be obtained even with low doses of rC1:rC2, which is beneficial for the survival of islets.

  8. Endogenous and recombinant type I interferons and disease activity in multiple sclerosis

    DEFF Research Database (Denmark)

    Sellebjerg, Finn; Krakauer, Martin; Limborg, Signe

    2012-01-01

    the percentage of CD4+ T cells expressing CD71 and HLA-DR (activated T cells), and this was associated with an increased risk of clinical disease activity. In contrast, induction of CD71 and HLA-DR was not observed in untreated MS patients with evidence of endogenous type IFN I activity. In conclusion......Although treatment of multiple sclerosis (MS) with the type I interferon (IFN) IFN-ß lowers disease activity, the role of endogenous type I IFN in MS remains controversial. We studied CD4+ T cells and CD4+ T cell subsets, monocytes and dendritic cells by flow cytometry and analysed the relationship...... with endogenous type I IFN-like activity, the effect of IFN-ß therapy, and clinical and magnetic resonance imaging (MRI) disease activity in MS patients. Endogenous type I IFN activity was associated with decreased expression of the integrin subunit CD49d (VLA-4) on CD4+CD26(high) T cells (Th1 helper cells...

  9. Molecular chaperone assisted expression systems: obtaining pure soluble and active recombinant proteins for structural and therapeutic purposes

    CSIR Research Space (South Africa)

    Makhoba, XH

    2015-09-01

    Full Text Available For many years recombinant protein production has been at the center of biosciences used for structural and therapeutic purposes. The production of recombinant proteins in foreign host system such as E. coli has been a biggest challenge. This has...

  10. Pharmacodynamics of recombinant activated factor VII and plasma-derived factor VII in a cohort of severe FVII deficient patients.

    Science.gov (United States)

    van Geffen, Mark; Mathijssen, Natascha C J; Holme, Pål A; Laros-van Gorkom, Britta A P; van Kraaij, Marian G J; Masereeuw, Roselinde; Peyvandi, Flora; van Heerde, Waander L

    2013-07-01

    Recombinant activated factor VII (rFVIIa) and plasma-derived factor VII (pdFVII) are used to prevent bleedings in severe FVII deficient patients, despite their short half-lifes. It is suggested that FVII levels of 15-20 IU/dL are sufficient to maintain hemostasis. We analyzed the pharmacodynamic effects of FVII substitution therapy in the Nijmegen Hemostasis Assay (NHA) that simultaneously measures thrombin and plasmin generation. Ten severe FVII deficient patients were treated with 20 μg/kg rFVIIa or 25 IU/kg pdFVII in a cross-over design. Thrombin generation lag-time (TG-LT) was identified as an effect-response parameter. Pharmacodynamic analysis using a maximum effect model showed 50% reduction of the TG-LT effect at ~2 IU/dL FVII activity for both rFVIIa and pdFVII. The FVII activity to obtain TG-LT comparable to the upper limit of normal range in healthy controls (4 min) was given by the effective concentration (ECnormal), showing sufficient hemostasis at 3-4 IU/dL FVII activity. No association was seen between FVII activity and other thrombin or plasmin generation parameters as measured by NHA. In conclusion, 3-4 IU/dL FVII activity seems sufficient to maintain hemostasis in patients with severe FVII deficiency during prophylaxis. These data may suggest a potential value for measurement of TG-LT in the monitoring of FVII(a) therapy. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Reasons for the lack of benefit of immediate angioplasty during recombinant tissue plasminogen activator therapy for acute myocardial infarction: a regional wall motion analysis. European Cooperative Study Group

    NARCIS (Netherlands)

    Arnold, A. E.; Serruys, P. W.; Rutsch, W.; Simoons, M. L.; de Bono, D. P.; Tijssen, J. G.; Lubsen, J.; Verstraete, M.

    1991-01-01

    Regional ventricular wall motion analysis utilizing three different methods was performed on predischarge left ventriculograms from 291 of 367 patients enrolled in a randomized trial of single chain recombinant tissue-type plasminogen activator (rt-PA), aspirin and heparin with and without immediate

  12. Increased volume of distribution for recombinant activated factor VII and longer plasma-derived factor VII half-life may explain their long lasting prophylactic effect

    NARCIS (Netherlands)

    Mathijssen, N.C.J.; Masereeuw, R.; Holme, P.A.; Kraaij, M.G.J. van; Laros, B.A.P.; Peyvandi, F.; Heerde, W.L. van

    2013-01-01

    INTRODUCTION: Prophylaxis with plasma-derived or recombinant activated factor VII is beneficial in severe factor VII deficiency. To understand why prophylactic treatment with both products is efficacious, we conducted a pharmacokinetic study. MATERIALS AND METHODS: Ten factor VII deficient patients

  13. Prediction of human pharmacokinetics of activated recombinant factor VII and B-domain truncated factor VIII from animal population pharmacokinetic models of haemophilia

    DEFF Research Database (Denmark)

    Larsen, Malte Selch; Juul, Rasmus Vestergaard; Groth, Andreas Velsing

    2018-01-01

    activated factor VII (rFVIIa) and recombinant factor VIII (rFVIII) in several experimental animal models using population PK modelling, and apply a simulation-based approach to evaluate how well the developed animal population PK models predict human PK. PK models were developed for rFVIIa and r...

  14. Safety and efficacy of recombinant activated factor VII: a randomized placebo-controlled trial in the setting of bleeding after cardiac surgery

    DEFF Research Database (Denmark)

    Gill, Ravi; Herbertson, Mike; Vuylsteke, Alain

    2009-01-01

    BACKGROUND: Blood loss is a common complication of cardiac surgery. Evidence suggests that recombinant activated factor VII (rFVIIa) can decrease intractable bleeding in patients after cardiac surgery. Our objective was to investigate the safety and possible benefits of rFVIIa in patients who bleed...

  15. The biological activity of a recombinantly expressed (His)(6)-tagged peanut allergen (rAra h 1) is unaffected by endotoxin removal

    DEFF Research Database (Denmark)

    Jensen, Louise Bjerremann; Torp, Anna Maria; Andersen, Sven Bode

    2008-01-01

    The application of recombinant (His)(6)-tagged proteins in cell culture assays is associated with problems due to lipopolysaccharide (LPS) contamination. LPS stimulates cells of the immune system, thereby masking antigen-specific activation of T cells. Due to the affinity of LPS for histidine it ...

  16. The immunophenotypic and immunogenotypic B-cell differentiation arrest in bone marrow of RAG-deficient SCID patients corresponds to residual recombination activities of mutated RAG proteins

    NARCIS (Netherlands)

    J.G. Noordzij; S. de Bruin-Versteeg (Sandra); N.S. Verkaik (Nicole); J.M.J.J. Vossen; R. de Groot (Ronald); E. Bernatowska (Ewa); A.W. Langerak (Anton); D.C. van Gent (Dik); J.J.M. van Dongen (Jacques)

    2002-01-01

    textabstractThe protein products of the recombination activating genes (RAG1 and RAG2) initiate the formation of immunoglobulin (Ig) and T-cell receptors, which are essential for B- and T-cell development, respectively. Mutations in the RAG genes result in severe combined

  17. Investigation of the recombination losses in a three-electrode cylindrical ionization chamber developed for gamma ray dosimetry of fission product activity

    International Nuclear Information System (INIS)

    Ahmad, N.; Matiullah

    1995-01-01

    A three-electrode ionization chamber has been designed and developed for the gamma ray dosimetry of fission product activity and reported elsewhere. In this paper, the (I, V) characteristics of the chamber filled, with argon gas at 1.24 MPa (180 psi) pressure, for fission product gamma rays from spent fuel have been studied. To do so, the chamber was irradiated with gamma rays using different numbers of (i.e. up to 4) spent fuel elements. The plateau region is reached above 1200 V and the detector operating voltage is found to be 2 kV. It is observed that in the plateau region the slope increases with an increase in the exposure rate. The (1/I, 1/V) and (I, 1/V 2 ) characteristic curves reveal the presence of the initial and volume recombination losses. The volume recombination losses are found to be smaller than the initial recombination losses. Both these losses increase with the increasing exposure rate but the increase in the volume recombination losses is slightly greater than that of the initial recombination losses. (orig.)

  18. Neurotherapeutic activity of the recombinant heat shock protein Hsp70 in a model of focal cerebral ischemia in rats

    Directory of Open Access Journals (Sweden)

    Shevtsov MA

    2014-05-01

    Full Text Available Maxim A Shevtsov,1,2 Boris P Nikolaev,3 Ludmila Y Yakovleva,3 Anatolii V Dobrodumov,4 Anastasiy S Dayneko,5 Alexey A Shmonin,5,6 Timur D Vlasov,5 Elena V Melnikova,5 Alexander D Vilisov,4,5 Irina V Guzhova,1 Alexander M Ischenko,3 Anastasiya L Mikhrina,7 Oleg V Galibin,5 Igor V Yakovenko,2 Boris A Margulis1 1Institute of Cytology of the Russian Academy of Sciences (RAS, St Petersburg, Russia; 2AL Polenov Russian Research Scientific Institute of Neurosurgery, St Petersburg, Russia; 3Research Institute of Highly Pure Biopreparations, St Petersburg, Russia; 4Institute of Macromolecular Compounds of the Russian Academy of Sciences (RAS, St Petersburg, Russia; 5First St Petersburg IP Pavlov State Medical University, St Petersburg, Russia; 6Federal Almazov Medical Research Centre, St Petersburg, Russia; 7IM Sechenov Institute of Evolutionary Physiology and Biochemistry of the Russian Academy of Sciences (RAS, St Petersburg, Russia Abstract: Recombinant 70 kDa heat shock protein (Hsp70 is an antiapoptotic protein that has a cell protective activity in stress stimuli and thus could be a useful therapeutic agent in the management of patients with acute ischemic stroke. The neuroprotective and neurotherapeutic activity of recombinant Hsp70 was explored in a model of experimental stroke in rats. Ischemia was produced by the occlusion of the middle cerebral artery for 45 minutes. To assess its neuroprotective capacity, Hsp70, at various concentrations, was intravenously injected 20 minutes prior to ischemia. Forty-eight hours after ischemia, rats were sacrificed and brain tissue sections were stained with 2% triphenyl tetrazolium chloride. Preliminary treatment with Hsp70 significantly reduced the ischemic zone (optimal response at 2.5 mg/kg. To assess Hsp70’s neurotherapeutic activity, we intravenously administered Hsp70 via the tail vein 2 hours after reperfusion (2 hours and 45 minutes after ischemia. Rats were then kept alive for 72 hours. The

  19. Activities of wildtype and mutant p53 in suppression of homologous recombination as measured by a retroviral vector system

    International Nuclear Information System (INIS)

    Lu Xiongbin; Lozano, Guillermina; Donehower, Lawrence A.

    2003-01-01

    DNA repair of double strand breaks, interstrand DNA cross-links, and other types of DNA damage utilizes the processes of homologous recombination and non-homologous end joining to repair the damage. Aberrant homologous recombination is likely to be responsible for a significant fraction of chromosomal deletions, duplications, and translocations that are observed in cancer cells. To facilitate measurement of homologous recombination frequencies in normal cells, mutant cells, and cancer cells, we have developed a high titer retroviral vector containing tandem repeats of mutant versions of a GFP-Zeocin resistance fusion gene and an intact neomycin resistance marker. Recombination between the tandem repeats regenerates a functional GFP-Zeo R marker that can be easily scored. This retroviral vector was used to assess homologous recombination frequencies in human cancer cells and rodent fibroblasts with differing dosages of wild type or mutant p53. Absence of wild type p53 stimulated spontaneous and ionizing radiation-induced homologous recombination, confirming previous studies. Moreover, p53 +/- mouse fibroblasts show elevated levels of homologous recombination compared to their p53 +/+ counterparts following retroviral vector infection, indicating that p53 is haploinsufficient for suppression of homologous recombination. Transfection of vector-containing p53 null Saos-2 cells with various human cancer-associated p53 mutants revealed that these altered p53 proteins retain some recombination suppression function despite being totally inactive for transcriptional transactivation. The retroviral vector utilized in these studies may be useful in performing recombination assays on a wide array of cell types, including those not readily transfected by normal vectors

  20. A role for very low-dose recombinant activated factor VII in refractory bleeding after cardiac surgery: Lessons from an observational study.

    Science.gov (United States)

    Hoffmann, Till; Assmann, Alexander; Dierksen, Angelika; Roussel, Elisabeth; Ullrich, Sebastian; Lichtenberg, Artur; Albert, Alexander; Sixt, Stephan

    2018-04-18

    Although off-label use of recombinant activated factor VII against refractory bleeding is incorporated in current guideline recommendations, safety concerns persist predominantly with respect to thromboembolic complications. We analyzed the safety and efficacy of recombinant activated factor VII at a very low dose in cardiosurgical patients with refractory bleeding. This prospective study includes 1180 cardiosurgical patients at risk of bleeding. Goal-directed substitution was based on real-time laboratory testing and clinical scoring of the bleeding intensity. All patients who fulfilled the criteria for enhanced risk of bleeding (n = 281) were consequently included in the present analysis. Patients in whom refractory bleeding developed despite substitution with specific hemostatic compounds (n = 167) received a single shot of very low-dose recombinant activated factor VII (≤20 μg/kg). Mortality and risk of thromboembolic complications, and freedom from stroke and acute myocardial infarction in particular, were analyzed (vs patients without recombinant activated factor VII) by multivariable logistic and Cox regression analyses, as well as Kaplan-Meier estimates. There was no increase in rates of mortality (30-day mortality 4.2% vs 7.0% with P = .418; follow-up survival 85.6% at 13.0 [interquartile range, 8.4-15.7] months vs 80.7% at 10.2 [interquartile range, 7.2-16.1] months with P = .151), thromboembolic complications (6.6% vs 9.6% with P = .637), renal insufficiency, need for percutaneous coronary intervention, duration of ventilation, duration of hospital stay, or rehospitalization in patients receiving very low-dose recombinant activated factor VII compared with patients not receiving recombinant activated factor VII. Complete hemostasis without any need for further hemostatic treatment was achieved after very low-dose recombinant activated factor VII administration in the majority of patients (up to 88.6% vs 0% with P factor VII treatment of

  1. Mediator facilitates transcriptional activation and dynamic long-range contacts at the IgH locus during class switch recombination.

    Science.gov (United States)

    Thomas-Claudepierre, Anne-Sophie; Robert, Isabelle; Rocha, Pedro P; Raviram, Ramya; Schiavo, Ebe; Heyer, Vincent; Bonneau, Richard; Luo, Vincent M; Reddy, Janardan K; Borggrefe, Tilman; Skok, Jane A; Reina-San-Martin, Bernardo

    2016-03-07

    Immunoglobulin (Ig) class switch recombination (CSR) is initiated by the transcription-coupled recruitment of activation-induced cytidine deaminase (AID) to Ig switch regions (S regions). During CSR, the IgH locus undergoes dynamic three-dimensional structural changes in which promoters, enhancers, and S regions are brought to close proximity. Nevertheless, little is known about the underlying mechanisms. In this study, we show that Med1 and Med12, two subunits of the mediator complex implicated in transcription initiation and long-range enhancer/promoter loop formation, are dynamically recruited to the IgH locus enhancers and the acceptor regions during CSR and that their knockdown in CH12 cells results in impaired CSR. Furthermore, we show that conditional inactivation of Med1 in B cells results in defective CSR and reduced acceptor S region transcription. Finally, we show that in B cells undergoing CSR, the dynamic long-range contacts between the IgH enhancers and the acceptor regions correlate with Med1 and Med12 binding and that they happen at a reduced frequency in Med1-deficient B cells. Our results implicate the mediator complex in the mechanism of CSR and are consistent with a model in which mediator facilitates the long-range contacts between S regions and the IgH locus enhancers during CSR and their transcriptional activation. © 2016 Thomas-Claudepierre et al.

  2. 75 FR 69687 - Office of Biotechnology Activities Recombinant DNA Research: Proposed Actions Under the NIH...

    Science.gov (United States)

    2010-11-15

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... to the NIH Office of Biotechnology Activities (OBA). The data to be considered for certifying a new... same e-mail address or by fax at 301-496-9839 or sent by U.S. mail to the Office of Biotechnology...

  3. 76 FR 44339 - Office of Biotechnology Activities; Recombinant DNA Research: Action Under the NIH Guidelines for...

    Science.gov (United States)

    2011-07-25

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES National Institutes of Health Office of Biotechnology... Services. ACTION: Proposed Minor Action under the NIH Guidelines. SUMMARY: The Office of Biotechnology....nih.gov , telephone (301-496-9838), or mail to the Office of Biotechnology Activities, National...

  4. Neuronal targeting, internalization, and biological activity of a recombinant atoxic derivative of botulinum neurotoxin A

    Science.gov (United States)

    Botulinum neurotoxins (BoNT) have the unique capacity to cross epithelial barriers, target neuromuscular junctions, and translocate active metalloprotease component to the cytosol of motor neurons. We have taken advantage of the molecular carriers responsible for this trafficking to create a family ...

  5. Design of Recombinant Stem Cell Factor macrophage Colony Stimulating Factor Fusion Proteins and their Biological Activity In Vitro

    Science.gov (United States)

    Chen, Tao; Yang, Jie; Wang, Yuelang; Zhan, Chenyang; Zang, Yuhui; Qin, Junchuan

    2005-05-01

    Stem cell factor (SCF) and macrophage colony stimulating factor (M-CSF) can act in synergistic way to promote the growth of mononuclear phagocytes. SCF-M-CSF fusion proteins were designed on the computer using the Homology and Biopolymer modules of the software packages InsightII. Several existing crystal structures were used as templates to generate models of the complexes of receptor with fusion protein. The structure rationality of the fusion protein incorporated a series of flexible linker peptide was analyzed on InsightII system. Then, a suitable peptide GGGGSGGGGSGG was chosen for the fusion protein. Two recombinant SCF-M-CSF fusion proteins were generated by construction of a plasmid in which the coding regions of human SCF (1-165aa) and M-CSF (1-149aa) cDNA were connected by this linker peptide coding sequence followed by subsequent expression in insect cell. The results of Western blot and activity analysis showed that these two recombinant fusion proteins existed as a dimer with a molecular weight of 84 KD under non-reducing conditions and a monomer of 42 KD at reducing condition. The results of cell proliferation assays showed that each fusion protein induced a dose-dependent proliferative response. At equimolar concentration, SCF/M-CSF was about 20 times more potent than the standard monomeric SCF in stimulating TF-1 cell line growth, while M-CSF/SCF was 10 times of monomeric SCF. No activity difference of M-CSF/SCF or SCF/M-CSF to M-CSF (at same molar) was found in stimulating the HL-60 cell linear growth. The synergistic effect of SCF and M-CSF moieties in the fusion proteins was demonstrated by the result of clonogenic assay performed with human bone mononuclear, in which both SCF/M-CSF and M-CSF/SCF induced much higher number of CFU-M than equimolar amount of SCF or M-CSF or that of two cytokines mixture.

  6. Biostable Agonists that Match or Exceed Activity of Native Insect Kinins on Recombinant Arthropod GPCRs

    Science.gov (United States)

    2009-01-01

    Drosophila melanogaster and the honey bee Apis mellifera. Prog. Neurobiol. 80, 1–19. Holman, G.M., Nachman, R.J., Wright, M.S., 1990. Insect...Introduction G- Protein -coupled receptors (GPCRs) are seven transmembrane cell surface proteins that are activated by diverse stimuli such as biogenic amines...neuropeptides and protein hormones. A distinct intracellular response, mostly through their heterotrimeric G-pro- tein, is initiated when GPCRs are

  7. Processing of natural and recombinant CXCR3-targeting chemokines and implications for biological activity.

    Science.gov (United States)

    Hensbergen, P J; van der Raaij-Helmer, E M; Dijkman, R; van der Schors, R C; Werner-Felmayer, G; Boorsma, D M; Scheper, R J; Willemze, R; Tensen, C P

    2001-09-01

    Chemokines comprise a class of peptides with chemotactic activity towards leukocytes. The potency of different chemokines for the same receptor often varies as a result of differences in primary structure. In addition, post-translational modifications have been shown to affect the effectiveness of chemokines. Although in several studies, natural CXCR3-targeting chemokines have been isolated, detailed information about the proteins and their possible modifications is lacking. Using a combination of liquid chromatography and mass spectrometry we studied the protein profile of CXCR3-targeting chemokines expressed by interferon-gamma-stimulated human keratinocytes. The biological implications of one of the identified modifications was studied in more detail using calcium mobilization and chemotaxis assays. We found that the primary structure of human CXCL10 is different from the generally accepted sequence. In addition we identified a C-terminally truncated CXCL10, lacking the last four amino acids. Native CXCL11 was primarily found in its intact mature form but we also found a mass corresponding to an N-terminally truncated human CXCL11, lacking the first two amino acids FP, indicating that this chemokine is a substrate for dipeptidylpeptidase IV. Interestingly, this same truncation was found when we expressed human CXCL11 in Drosophila S2 cells. The biological activity of this truncated form of CXCL11 was greatly reduced, both in calcium mobilization (using CXCR3 expressing CHO cells) as well as its chemotactic activity for CXCR3-expressing T-cells. It is concluded that detailed information on chemokines at the protein level is important to characterize the exact profile of these chemotactic peptides as modifications can severely alter their biological activity.

  8. Expression and fast preparation of biologically active recombinant human coagulation factor VII in CHO-K1 cells.

    Science.gov (United States)

    Xiao, W; Li, C Q; Xiao, X P; Lin, F Z

    2013-12-16

    Human coagulation factor VII (FVII) plays an important role in the blood coagulation process and exists in micro amounts in human plasma; therefore, any attempt at the large-scale production of FVII in significant quantities is challenging. The purpose of this study was to express and obtain biologically active recombinant FVII (rFVII) from Chinese hamster ovary K1 (CHO-K1) cells. The full-length FVII cDNA was isolated from a HepG2 cell line and then subcloned in pcDNA3.1 to construct an expression vector, pcDNA-FVII. CHO-K1 cells were transfected with 1 µg pcDNA-FVII. The cell line that stably expressed secretory FVII was screened using 900 µg/mL G418. The FVII copy number in CHO-K1 cells was detected by quantitative polymerase chain reaction (qPCR). The rFVII was purified in ligand affinity chromatography medium. The purified protein was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot analysis. The biological activity of the purified FVII protein was determined by a prothrombin time assay. Three cell lines that permanently expressed rFVII were screened. The qPCR results demonstrated that each CHO-K1 cell harbored two FVII DNA copies. The SDS-PAGE and Western blot analysis showed that the purified protein was about 50 kDa. The purity of the target protein was 95%. The prothrombin time assay indicated that the FVII-specific activity of rFVII was 2573 ± 75 IU/mg. This method enabled the fast preparation of high-purity rFVII from CHO-K1 cells, and the purified protein had good biological activity.

  9. Integrin specificity and enhanced cellular activities associated with surfaces presenting a recombinant fibronectin fragment compared to RGD supports.

    Science.gov (United States)

    Petrie, Timothy A; Capadona, Jeffrey R; Reyes, Catherine D; García, Andrés J

    2006-11-01

    Biomimetic strategies focusing on presenting short bioadhesive oligopeptides, including the arginine-glycine-aspartic acid (RGD) motif present in numerous adhesive proteins, on a non-fouling support have emerged as promising approaches to improve cellular activities and healing responses. Nevertheless, these bio-inspired strategies are limited by low activity of the oligopeptides compared to the native ligand due to the absence of complementary or modulatory domains. In the present analysis, we generated well-defined biointerfaces presenting RGD-based ligands of increasing complexity to directly compare their biological activities in terms of cell adhesion strength, integrin binding and signaling. Mixed self-assembled monolayers of alkanethiols on gold were optimized to engineer robust supports that present anchoring groups for ligand tethering within a non-fouling, protein adsorption-resistant background. Controlled bioadhesive interfaces were generated by tethering adhesive ligands via standard peptide chemistry. On a molar basis, biointerfaces functionalized with the FNIII7-10 recombinant fragment presenting the RGD and PHSRN adhesive motifs in the correct structural context exhibited significantly higher adhesion strength, FAK activation, and cell proliferation rate than supports presenting RGD ligand or RGD-PHSRN, an oligopeptide presenting these two sites separated by a polyglycine linker. Moreover, FNIII7-10-functionalized surfaces displayed specificity for alpha5beta1 integrin, while cell adhesion to supports presenting RGD or RGD-PHSRN was primarily mediated by alphavbeta3 integrin. These results are significant to the rational engineering of bioactive materials that convey integrin binding specificity for directed cellular and tissue responses in biomedical and biotechnological applications.

  10. Spectrophotometric activity microassay for pure and recombinant cytochrome P450-type nitric oxide reductase

    CSIR Research Space (South Africa)

    Garny, S

    2014-02-01

    Full Text Available spectrophotometric quantification of NADH [19]. Kaya et al. (2004) [19] demonstrated the linearly proportional relationship between the oxidation of NADH to NAD+, with the release of NO from NOC-5, but did not develop a kinetic assay for NOR activity using... this principle, the primary aim of this study. Nakahara et al. (1993) [10] determined the stoichiometry of NO reduction by NOR as 2:1:1 for NO:NADH:N2O. Therefore, for each NADH oxidized to NAD+, two molecules of NO are converted to N2O (refer Equation 1). 2...

  11. Activation of the cellular unfolded protein response by recombinant adeno-associated virus vectors.

    Directory of Open Access Journals (Sweden)

    Balaji Balakrishnan

    Full Text Available The unfolded protein response (UPR is a stress-induced cyto-protective mechanism elicited towards an influx of large amount of proteins in the endoplasmic reticulum (ER. In the present study, we evaluated if AAV manipulates the UPR pathways during its infection. We first examined the role of the three major UPR axes, namely, endoribonuclease inositol-requiring enzyme-1 (IRE1α, activating transcription factor 6 (ATF6 and PKR-like ER kinase (PERK in AAV infected cells. Total RNA from mock or AAV infected HeLa cells were used to determine the levels of 8 different ER-stress responsive transcripts from these pathways. We observed a significant up-regulation of IRE1α (up to 11 fold and PERK (up to 8 fold genes 12-48 hours after infection with self-complementary (scAAV2 but less prominent with single-stranded (ssAAV2 vectors. Further studies demonstrated that scAAV1 and scAAV6 also induce cellular UPR in vitro, with AAV1 vectors activating the PERK pathway (3 fold while AAV6 vectors induced a significant increase on all the three major UPR pathways [6-16 fold]. These data suggest that the type and strength of UPR activation is dependent on the viral capsid. We then examined if transient inhibition of UPR pathways by RNA interference has an effect on AAV transduction. siRNA mediated silencing of PERK and IRE1α had a modest effect on AAV2 and AAV6 mediated gene expression (∼1.5-2 fold in vitro. Furthermore, hepatic gene transfer of scAAV2 vectors in vivo, strongly elevated IRE1α and PERK pathways (2 and 3.5 fold, respectively. However, when animals were pre-treated with a pharmacological UPR inhibitor (metformin during scAAV2 gene transfer, the UPR signalling and its subsequent inflammatory response was attenuated concomitant to a modest 2.8 fold increase in transgene expression. Collectively, these data suggest that AAV vectors activate the cellular UPR pathways and their selective inhibition may be beneficial during AAV mediated gene transfer.

  12. Spectrum Recombination.

    Science.gov (United States)

    Greenslade, Thomas B., Jr.

    1984-01-01

    Describes several methods of executing lecture demonstrations involving the recombination of the spectrum. Groups the techniques into two general classes: bringing selected portions of the spectrum together using lenses or mirrors and blurring the colors by rapid movement or foreshortening. (JM)

  13. In Plant Activation: An Inducible, Hyperexpression Platform for Recombinant Protein Production in Plants[W][OPEN

    Science.gov (United States)

    Dugdale, Benjamin; Mortimer, Cara L.; Kato, Maiko; James, Tess A.; Harding, Robert M.; Dale, James L.

    2013-01-01

    In this study, we describe a novel protein production platform that provides both activation and amplification of transgene expression in planta. The In Plant Activation (INPACT) system is based on the replication machinery of tobacco yellow dwarf mastrevirus (TYDV) and is essentially transient gene expression from a stably transformed plant, thus combining the advantages of both means of expression. The INPACT cassette is uniquely arranged such that the gene of interest is split and only reconstituted in the presence of the TYDV-encoded Rep/RepA proteins. Rep/RepA expression is placed under the control of the AlcA:AlcR gene switch, which is responsive to trace levels of ethanol. Transgenic tobacco (Nicotiana tabacum cv Samsun) plants containing an INPACT cassette encoding the β-glucuronidase (GUS) reporter had negligible background expression but accumulated very high GUS levels (up to 10% total soluble protein) throughout the plant, within 3 d of a 1% ethanol application. The GUS reporter was replaced with a gene encoding a lethal ribonuclease, barnase, demonstrating that the INPACT system provides exquisite control of transgene expression and can be adapted to potentially toxic or inhibitory compounds. The INPACT gene expression platform is scalable, not host-limited, and has been used to express both a therapeutic and an industrial protein. PMID:23839786

  14. Analysis of the Peroxidase Activity of Rice (Oryza Sativa) Recombinant Hemoglobin 1: Implications for the In Vivo Function of Hexacoordinate Non-Symbiotic Hemoglobins in Plants

    Science.gov (United States)

    In plants, it has been proposed that hexacoordinate (class 1) non-symbiotic Hbs (nsHb-1) function in vivo as peroxidases. However, little is known about the peroxidase activity of nsHb-1. We evaluated the peroxidase activity of rice recombinant Hb1 (a nsHb-1) by using the guaiacol/H2O2 system at pH ...

  15. Analysis of the technique Thermal Desorption Spectroscopy (TDS) and its Application for the Characterization of Metal -Hydrogen Systems; Analisis de la Tecnica Espectroscopia de Desorcion Termica (TDS) y su Applicacion para la Caracterizacion de Sistemas Metal-Hydrogeno

    Energy Technology Data Exchange (ETDEWEB)

    Castro, F J [Comision Nacional de Energia Atomica, Centro Atomico Bariloche (Argentina)

    2000-07-01

    limiting step is the recombination of two hydrogen atoms on the surface of the material. When the surface of the sample is in the a phase (solid solution) the rate limiting step is one of the processes that occurs on the surface of the material: the transfer of a hydrogen atom from the bulk to the surface or the recombination and desorption on the surface. By fitting the spectra we obtain an activation energy equal to 31 n 6 kJ/mol for the b phase, and equal to 35 n 3 kJ/mol for the a phase. We also compare the spectra of the powder with the spectra of the granules, foils and wires. Based on this comparison we analyze the effect on the desorption spectra of the characteristic size and geometry of the samples.Finally, we present a study of hydrogen desorption in the Pd-H system poisoned with sulfur. The poisoning produces as main effects a delay of the absorption and desorption processes without any appreciable loss in the storage capacity of the material.The experimental apparatus and theoretical models developed have been applied to the study of a MH system using samples with different morphology, characteristic size, geometry and surface state. The spectra were measured for different hydrogen concentrations and heating speeds. The results obtained encourage the utilization of TDS for the study and characterization of hydrogen desorption in MH systems. The technique is suited for the detailed analysis of the physical properties of the system and for the qualitative evaluation of the kinetic processes and their possible influence on technological devices.

  16. A SEP tag enhances the expression, solubility and yield of recombinant TEV protease without altering its activity.

    Science.gov (United States)

    Nautiyal, Kalpana; Kuroda, Yutaka

    2018-05-25

    Tobacco Etch Virus (TEV) protease is used in the purification of recombinant proteins, but its usage is often hampered by solubility issues. Here, we report a short, 12-residue solubility enhancing peptide (SEP) tag attached at the C-terminus of TEV (TEV-C9R). We assessed the effects of the C9R tag on the biophysical and biochemical characteristics of TEV. The yield of HPLC purified TEV-C9R expressed in E. coli grown in 200 mL LB or TB media was between 10 and 13 mg, which was up to 6.5 times higher than the yield of the untagged TEV (untagged-TEV). TEV-C9R was active over a pH range of 5-8, which was wider than that of the commonly used thrombin, and it remained active upon incubation at 60 °C much longer than the untagged-TEV, which aggregated at this temperature. Static and dynamic light scattering demonstrated the higher solubility of purified TEV-C9R. Furthermore, the thermal unfolding of TEV-C9R, as assessed by circular dichroism at pH 4.7, was almost perfectly reversible, in contrast to that of untagged-TEV, which aggregated at high temperature. These results demonstrate the improved biophysical and biochemical characteristics of TEV-C9R originating from higher solubility and provide another example of how SEP tags can enhance enzyme solubility without altering its activity. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Recombinant Trichoderma harzianum endoglucanase I (Cel7B) is a highly acidic and promiscuous carbohydrate-active enzyme.

    Science.gov (United States)

    Pellegrini, Vanessa O A; Serpa, Viviane Isabel; Godoy, Andre S; Camilo, Cesar M; Bernardes, Amanda; Rezende, Camila A; Junior, Nei Pereira; Franco Cairo, João Paulo L; Squina, Fabio M; Polikarpov, Igor

    2015-11-01

    Trichoderma filamentous fungi have been investigated due to their ability to secrete cellulases which find various biotechnological applications such as biomass hydrolysis and cellulosic ethanol production. Previous studies demonstrated that Trichoderma harzianum IOC-3844 has a high degree of cellulolytic activity and potential for biomass hydrolysis. However, enzymatic, biochemical, and structural studies of cellulases from T. harzianum are scarce. This work reports biochemical characterization of the recombinant endoglucanase I from T. harzianum, ThCel7B, and its catalytic core domain. The constructs display optimum activity at 55 °C and a surprisingly acidic pH optimum of 3.0. The full-length enzyme is able to hydrolyze a variety of substrates, with high specific activity: 75 U/mg for β-glucan, 46 U/mg toward xyloglucan, 39 U/mg for lichenan, 26 U/mg for carboxymethyl cellulose, 18 U/mg for 4-nitrophenyl β-D-cellobioside, 16 U/mg for rye arabinoxylan, and 12 U/mg toward xylan. The enzyme also hydrolyzed filter paper, phosphoric acid swollen cellulose, Sigmacell 20, Avicel PH-101, and cellulose, albeit with lower efficiency. The ThCel7B catalytic domain displays similar substrate diversity. Fluorescence-based thermal shift assays showed that thermal stability is highest at pH 5.0. We determined kinetic parameters and analyzed a pattern of oligosaccharide substrates hydrolysis, revealing cellobiose as a final product of C6 degradation. Finally, we visualized effects of ThCel7B on oat spelt using scanning electron microscopy, demonstrating the morphological changes of the substrate during the hydrolysis. The acidic behavior of ThCel7B and its considerable thermostability hold a promise of its industrial applications and other biotechnological uses under extremely acidic conditions.

  18. Optimization of recombinant bacteria expressing dsRNA to enhance insecticidal activity against a lepidopteran insect, Spodoptera exigua.

    Directory of Open Access Journals (Sweden)

    Mohammad Vatanparast

    Full Text Available Double-stranded RNA (dsRNA has been applied to control insect pests due to its induction of RNA interference (RNAi of a specific target gene expression. However, developing dsRNA-based insecticidal agent has been a great challenge especially against lepidopteran insect pests due to variations in RNAi efficiency. The objective of this study was to screen genes of chymotrypsins (SeCHYs essential for the survival of the beet armyworm, Spodoptera exigua, to construct insecticidal dsRNA. In addition, an optimal oral delivery method was developed using recombinant bacteria. At least 7 SeCHY genes were predicted from S. exigua transcriptomes. Subsequent analyses indicated that SeCHY2 was widely expressed in different developmental stages and larval tissues by RT-PCR and its expression knockdown by RNAi caused high mortality along with immunosuppression. However, a large amount of dsRNA was required to efficiently kill late instars of S. exigua because of high RNase activity in their midgut lumen. To minimize dsRNA degradation, bacterial expression and formulation of dsRNA were performed in HT115 Escherichia coli using L4440 expression vector. dsRNA (300 bp specific to SeCHY2 overexpressed in E. coli was toxic to S. exigua larvae after oral administration. To enhance dsRNA release from E. coli, bacterial cells were sonicated before oral administration. RNAi efficiency of sonicated bacteria was significantly increased, causing higher larval mortality at oral administration. Moreover, targeting young larvae possessing weak RNase activity in the midgut lumen significantly enhanced RNAi efficiency and subsequent insecticidal activity against S. exigua.

  19. Role of human recombinant activated protein C and low dose corticosteroid therapy in sepsis

    Directory of Open Access Journals (Sweden)

    Aparna Shukla

    2010-01-01

    Full Text Available Despite advances in modern medicine, sepsis remains a complex syndrome that has been associated with significant morbidity and mortality. Multiple organ failure associated with sepsis leads to high mortality and morbidity. About 28 - 50% deaths have been reported in patients with sepsis. The number of sepsis patients is increasing, with considerable burden on healthcare facilities. Various factors leading to a rise in the incidence of sepsis are (1 Improvement of diagnostic procedures (2 Increase in the number of immunocompromised patients taking treatment for various autoimmune disease, carcinomas, organ transplantation (3 Advances in intensive procedures (4 Nosocomial infections (5 Extensive use of antibiotics. With the better understanding of sepsis various modalities to modify pathophysiological response of septic patients have developed. Activated protein C and low-dose corticosteroid therapy have been tried in patients, with variable results.

  20. Massive Pulmonary Embolism: Treatment with Thrombus Fragmentation and Local Fibrinolysis with Recombinant Human-Tissue Plasminogen Activator

    International Nuclear Information System (INIS)

    Stock, Klaus Wilhelm; Jacob, Augustinus Ludwig; Schnabel, Karl Jakob; Bongartz, Georg; Steinbrich, Wolfgang

    1997-01-01

    Purpose: To report the results of thrombus fragmentation in combination with local fibrinolysis using recombinant human-tissue plasminogen activator (rtPA) in patients with massive pulmonary embolism. Methods: Five patients with massive pulmonary embolism were treated with thrombus fragmentation followed by intrapulmonary injection of rtPA. Clot fragmentation was performed with a guidewire, angiographic catheter, and balloon catheter. Three patients had undergone recent surgery; one of them received a reduced dosage of rtPA. Results: All patients survived and showed clinical improvement with a resultant significant (p < 0.05) decrease in the pulmonary blood pressure (mean systolic pulmonary blood pressure before treatment, 49 mmHg; 4 hr after treatment, 28 mmHg). Angiographic follow-up in three patients revealed a decrease in thrombus material and an increase in pulmonary perfusion. Two patients developed retroperitoneal hematomas requiring transfusion. Conclusion: Clot fragmentation and local fibrinolysis with rtPA was an effective therapy for massive pulmonary embolism. Bleeding at the puncture site was a frequent complication

  1. Outcomes Following Three-Factor Inactive Prothrombin Complex Concentrate Versus Recombinant Activated Factor VII Administration During Cardiac Surgery.

    Science.gov (United States)

    Harper, Patrick C; Smith, Mark M; Brinkman, Nathan J; Passe, Melissa A; Schroeder, Darrell R; Said, Sameh M; Nuttall, Gregory A; Oliver, William C; Barbara, David W

    2018-02-01

    To compare outcomes following inactive prothrombin complex concentrate (PCC) or recombinant activated factor VII (rFVIIa) administration during cardiac surgery. Retrospective propensity-matched analysis. Academic tertiary-care center. Patients undergoing cardiac surgery requiring cardiopulmonary bypass who received either rFVIIa or the inactive 3-factor PCC. Outcomes following intraoperative administration of rFVIIa (263) or factor IX complex (72) as rescue therapy to treat bleeding. In the 24 hours after surgery, propensity-matched patients receiving PCC versus rFVIIa had significantly less chest tube outputs (median difference -464 mL, 95% confidence interval [CI] -819 mL to -110 mL), fresh frozen plasma transfusion rates (17% v 38%, p = 0.028), and platelet transfusion rates (26% v 49%, p = 0.027). There were no significant differences between propensity-matched groups in postoperative stroke, deep venous thrombosis, pulmonary embolism, myocardial infarction, or intracardiac thrombus. Postoperative dialysis was significantly less likely in patients administered PCC versus rFVIIa following propensity matching (odds ratio = 0.3, 95% CI 0.1-0.7). No significant difference in 30-day mortality in patients receiving PCC versus rFVIIa was present following propensity matching. Use of rFVIIa versus inactive PCCs was significantly associated with renal failure requiring dialysis and increased postoperative bleeding and transfusions. Copyright © 2018 Elsevier Inc. All rights reserved.

  2. Solubilization and folding of a fully active recombinant Gaussia luciferase with native disulfide bonds by using a SEP-Tag.

    Science.gov (United States)

    Rathnayaka, Tharangani; Tawa, Minako; Nakamura, Takashi; Sohya, Shihori; Kuwajima, Kunihiro; Yohda, Masafumi; Kuroda, Yutaka

    2011-12-01

    Gaussia luciferase (GLuc) is the smallest known bioluminescent protein and is attracting much attention as a potential reporter protein. However, its 10 disulfide bond forming cysteines have hampered the efficient production of recombinant GLuc and thus limited its use in bio-imaging application. Here, we demonstrate that the addition of a short solubility enhancement peptide tag (SEP-Tag) to the C-terminus of GLuc (GLuc-C9D) significantly increased the fraction of soluble protein at a standard expression temperature. The expression time was much shorter, and the final yield of GLuc-C9D was significantly higher than with our previous pCold expression system. Reversed phase HPLC indicated that the GLuc-C9D variant folded with a single disulfide bond pattern after proper oxidization. Further, the thermal denaturation of GLuc-C9D was completely reversible, and its secondary structure content remained unchanged until 40°C as assessed by CD spectroscopy. The (1)H-NMR spectrum of GLuc indicated sharp well dispersed peaks typical for natively folded proteins. GLuc-C9D bioluminescence activity was strong and fully retained even after incubation at high temperatures. These results suggest that solubilization using SEP-Tags can be useful for producing large quantities of proteins containing multiple disulfide bonds. Copyright © 2011. Published by Elsevier B.V.

  3. Efficacy and safety of a modified intravenous recombinant tissue plasminogen activator regimen in Chinese patients with acute ischemic stroke.

    Science.gov (United States)

    Pan, Shu-Ming; Liu, Jia-Fu; Liu, Ming; Shen, Sa; Li, Hao-Jun; Dai, Li-Hua; Chen, Xiang-Jun

    2013-07-01

    Thrombolytic treatment with intravenous (IV) recombinant tissue plasminogen activator (rtPA; 0.90 mg/kg, with a maximum dose of 90 mg) has been recommended as the standard management for acute ischemic stroke (AIS) thrombolysis. However, the dose of IV rtPA in Asia remains controversial. This study was designed to verify the safety and efficacy of IV rtPA treatment for AIS with a lower dosage (0.90 mg/kg, with a maximum dose of 50 mg). Patients were divided into 3 dosage groups according to body weight (BW): group 1, 67 kg for descent were included in the study. The baseline characteristics of the 3 dosage groups were well matched. In group 1 (BW 67 kg for <0.75 mg/kg; n = 31; P = .362). There were no significantly statistical differences in the incidence of symptomatic intracerebral hemorrhage and mortality rate. This IV rtPA regimen (0.90 mg/kg, with a maximum dose of 50 mg) not only shows sufficient favorable outcome in clinical practice in Chinese patients with AIS but also good health economic savings. This regimen could be suitable for many developing countries. Copyright © 2013 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  4. Effects of edaravone on early outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator.

    Science.gov (United States)

    Wada, Tomoki; Yasunaga, Hideo; Inokuchi, Ryota; Horiguchi, Hiromasa; Fushimi, Kiyohide; Matsubara, Takehiro; Nakajima, Susumu; Yahagi, Naoki

    2014-10-15

    We investigated whether edaravone could improve early outcomes in acute ischemic stroke patients treated with recombinant tissue plasminogen activator (rtPA). We conducted a retrospective cohort study using the Japanese Diagnosis Procedure Combination database. We identified patients admitted with a primary diagnosis of ischemic stroke from 1 July 2010 to 31 March 2012 and treated with rtPA on the same day of stroke onset or the following day. Thereafter, we selected those who received edaravone on the same day of rtPA administration (edaravone group), and those who received rtPA without edaravone (control group). The primary outcomes were modified Rankin Scale (mRS) scores at discharge. One-to-one propensity-score matching was performed between the edaravone and control groups. An ordinal logistic regression analysis for mRS scores at discharge was performed with adjustment for possible variables as well as clustering of patients within hospitals using a generalized estimating equation. We identified 6336 eligible patients for inclusion in the edaravone group (n=5979; 94%) and the control group (n=357; 6%) as the total population. In 356 pairs of the propensity-matched population, the ordinal logistic regression analysis showed that edaravone was significantly associated with lower mRS scores of patients at discharge (adjusted odds ratio: 0.74; 95% confidence interval: 0.57-0.96). Edaravone may improve early outcomes in acute ischemic stroke patients treated with rtPA. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Expression, purification, and refolding of active recombinant human E-selectin lectin and EGF domains in Escherichia coli.

    Science.gov (United States)

    Kawano, Susumu; Iyaguchi, Daisuke; Okada, Chiaki; Sasaki, Yusuke; Toyota, Eiko

    2013-06-01

    Attempts to obtain active E-selectin from Escherichia coli (E. coli) have not yet been successful. In this study, we succeeded in expressing the recombinant lectin and epidermal growth factor domain fragments of human E-selectin (rh-ESLE) in E. coli on a large-scale. The rh-ESLE protein was expressed as an inactive form in the inclusion bodies. The inactive form of rh-ESLE was denatured and solubilized by 6 M guanidine hydrochloride and then purified by Ni(2+) affinity chromatography under denaturing conditions. Denatured rh-ESLE was then refolded by a rapid-dilution method using a large amount of refolding buffer, which contained arginine and cysteine/cystine. The refolded rh-ESLE showed binding affinity for sLe(X) (K(d) = 321 nM, B(max) = 1.9 pmol/μg protein). This result suggests that the refolded rh-ESLE recovered its native and functional structure.

  6. Prolonged activity of a recombinant factor VIII-Fc fusion protein in hemophilia A mice and dogs

    Science.gov (United States)

    Dumont, Jennifer A.; Liu, Tongyao; Low, Susan C.; Zhang, Xin; Kamphaus, George; Sakorafas, Paul; Fraley, Cara; Drager, Douglas; Reidy, Thomas; McCue, Justin; Franck, Helen W. G.; Merricks, Elizabeth P.; Nichols, Timothy C.; Bitonti, Alan J.; Pierce, Glenn F.

    2012-01-01

    Despite proven benefits, prophylactic treatment for hemophilia A is hampered by the short half-life of factor VIII. A recombinant factor VIII-Fc fusion protein (rFVIIIFc) was constructed to determine the potential for reduced frequency of dosing. rFVIIIFc has an ∼ 2-fold longer half-life than rFVIII in hemophilia A (HemA) mice and dogs. The extension of rFVIIIFc half-life requires interaction of Fc with the neonatal Fc receptor (FcRn). In FcRn knockout mice, the extension of rFVIIIFc half-life is abrogated, and is restored in human FcRn transgenic mice. The Fc fusion has no impact on FVIII-specific activity. rFVIIIFc has comparable acute efficacy as rFVIII in treating tail clip injury in HemA mice, and fully corrects whole blood clotting time (WBCT) in HemA dogs immediately after dosing. Furthermore, consistent with prolonged half-life, rFVIIIFc shows 2-fold longer prophylactic efficacy in protecting HemA mice from tail vein transection bleeding induced 24-48 hours after dosing. In HemA dogs, rFVIIIFc also sustains partial correction of WBCT 1.5- to 2-fold longer than rFVIII. rFVIIIFc was well tolerated in both species. Thus, the rescue of FVIII by Fc fusion to provide prolonged protection presents a novel pathway for FVIII catabolism, and warrants further investigation. PMID:22246033

  7. Newly diagnosed congenital factor VII deficiency and utilization of recombinant activated factor VII (NovoSeven(®)).

    Science.gov (United States)

    Bartosh, Nicole S; Tomlin, Tara; Cable, Christian; Halka, Kathleen

    2013-01-01

    This case report presents a newly diagnosed congenital factor VII deficiency treated with recombinant activated factor VII (rFVIIa). Congenital factor VII deficiency is a rare autosomal-recessive bleeding disorder that occurs in fewer than 1/500,000 persons. Its presentation can vary from epistaxis to hemarthroses and severe central nervous system bleeding, and correlates poorly with factor VII levels. Our patient had not had a significant hemostatic challenge prior to his presentation and therefore never had any symptomatology suggestive of this disease. He was treated with rFVIIa, and was able to undergo repair of his fractures without bleeding. A 19-year-old African-American male presented to the emergency room after an altercation that resulted in significant trauma. He sustained bilateral mandibular angle fractures and orbital floor fractures, requiring urgent surgical correction. On initial evaluation, he was noted to have a prolonged prothrombin time of 40.1 seconds, with an International Normalized Ratio of 4.0, a normal activated partial thromboplastin time of 29.9 seconds, and a platelet count of 241. After receiving vitamin K and fresh frozen plasma, he was taken to the operating room for a temporary rigid maxillomandibular fixation. A 1:1 mixing study with normal plasma corrected the prothrombin time (decreasing from 40.7 to 14.7 seconds) and a factor VII assay revealed 5% of the normal factor VII level. The patient was diagnosed with congenital factor VII deficiency. Due to his coagulopathy and the extensive surgical correction needed, rFVIIa was administered and surgery was accomplished without hemorrhagic sequelae. This case report and review describes a rare congenital disease, the history of rFVIIa use, and its mechanism. rFVIIA use in our patient provided a treatment option that allowed the necessary surgical correction, but further prospective studies on dose optimization would ensure adequate dosing with minimal risk of severe side effects.

  8. Newly diagnosed congenital factor VII deficiency and utilization of recombinant activated factor VII (NovoSeven®)

    Science.gov (United States)

    Bartosh, Nicole S; Tomlin, Tara; Cable, Christian; Halka, Kathleen

    2013-01-01

    This case report presents a newly diagnosed congenital factor VII deficiency treated with recombinant activated factor VII (rFVIIa). Congenital factor VII deficiency is a rare autosomal-recessive bleeding disorder that occurs in fewer than 1/500,000 persons. Its presentation can vary from epistaxis to hemarthroses and severe central nervous system bleeding, and correlates poorly with factor VII levels. Our patient had not had a significant hemostatic challenge prior to his presentation and therefore never had any symptomatology suggestive of this disease. He was treated with rFVIIa, and was able to undergo repair of his fractures without bleeding. Case report A 19-year-old African-American male presented to the emergency room after an altercation that resulted in significant trauma. He sustained bilateral mandibular angle fractures and orbital floor fractures, requiring urgent surgical correction. On initial evaluation, he was noted to have a prolonged prothrombin time of 40.1 seconds, with an International Normalized Ratio of 4.0, a normal activated partial thromboplastin time of 29.9 seconds, and a platelet count of 241. After receiving vitamin K and fresh frozen plasma, he was taken to the operating room for a temporary rigid maxillomandibular fixation. A 1:1 mixing study with normal plasma corrected the prothrombin time (decreasing from 40.7 to 14.7 seconds) and a factor VII assay revealed 5% of the normal factor VII level. The patient was diagnosed with congenital factor VII deficiency. Due to his coagulopathy and the extensive surgical correction needed, rFVIIa was administered and surgery was accomplished without hemorrhagic sequelae. Conclusion This case report and review describes a rare congenital disease, the history of rFVIIa use, and its mechanism. rFVIIA use in our patient provided a treatment option that allowed the necessary surgical correction, but further prospective studies on dose optimization would ensure adequate dosing with minimal risk of

  9. The next generation of sepsis clinical trial designs: what is next after the demise of recombinant human activated protein C?*.

    Science.gov (United States)

    Opal, Steven M; Dellinger, R Phillip; Vincent, Jean-Louis; Masur, Henry; Angus, Derek C

    2014-07-01

    The developmental pipeline for novel therapeutics to treat sepsis has diminished to a trickle compared to previous years of sepsis research. While enormous strides have been made in understanding the basic molecular mechanisms that underlie the pathophysiology of sepsis, a long list of novel agents have now been tested in clinical trials without a single immunomodulating therapy showing consistent benefit. The only antisepsis agent to successfully complete a phase III clinical trial was human recumbent activated protein C. This drug was taken off the market after a follow-up placebo-controlled trial (human recombinant activated Protein C Worldwide Evaluation of Severe Sepsis and septic Shock [PROWESS SHOCK]) failed to replicate the favorable results of the initial registration trial performed ten years earlier. We must critically reevaluate our basic approach to the preclinical and clinical evaluation of new sepsis therapies. We selected the major clinical studies that investigated interventional trials with novel therapies to treat sepsis over the last 30 years. Phase II and phase III trials investigating new treatments for sepsis and editorials and critiques of these studies. Selected manuscripts and clinical study reports were analyzed from sepsis trials. Specific shortcomings and potential pit falls in preclinical evaluation and clinical study design and analysis were reviewed and synthesized. After review and discussion, a series of 12 recommendations were generated with suggestions to guide future studies with new treatments for sepsis. We need to improve our ability to define appropriate molecular targets for preclinical development and develop better methods to determine the clinical value of novel sepsis agents. Clinical trials must have realistic sample sizes and meaningful endpoints. Biomarker-driven studies should be considered to categorize specific "at risk" populations most likely to benefit from a new treatment. Innovations in clinical trial design

  10. Efficacy and effectiveness of recombinant human activated protein C in severe sepsis of adults

    Directory of Open Access Journals (Sweden)

    Greiner, Wolfgang

    2007-07-01

    Full Text Available Introduction: Sepsis is defined as an invasion of microorganisms and/or their toxins into the blood associated the reaction of the organism to this invasion. Severe sepsis is a major cost driver in intensive care medicine. In Germany, prevalence data was assessed in the context of the German Prevalence Study. Severe sepsis has a prevalence of 35% in German intensive care units. Research questions: The following questions were analysed: is Drotrecogin alfa (activated (DAA effective in the treatment of patients with severe sepsis and a mixed risk of death, both in all patients and in different subgroups? Is DAA effective in the treatment of patients with severe sepsis and low risk of death? Is DAA cost effective in the treatment of patients with severe sepsis compared to placebo? Methods: Only studies with adult patients are included. There are no other exclusion criteria. A systematic literature search is performed by the German Institute of Medical Documentation and Information (DIMDI. The literature search yielded as a total of 847 hits. After screening of the abstracts, 165 medical and 101 economic publications were chosen for full text appraisal. Results: Therapy with DAA appears to be cost effective in reducing 28-day-mortality in patients with severe sepsis and a high risk of death. A high risk of death is indicated by the presence of multiorgan failure (≥2 and/or an APACHE-II-Score ≥25. Therapy with DAA is not associated with a long-term reduction of mortality at later follow-up assessments. Therapy with DAA is not associated with a long-term reduction of mortality at later follow-up assessments. Therapy with DAA is cost-effective in patients with multiorgan failure and/or an APACHE II Score (≥25. In patients with a lower risk of death, DAA is not cost-effective. Costs associated with bleeding events have been rarely included in cost calculations. Discussion: DAA appears to reduce mortality in patients with severe sepsis and a high

  11. Recombinational repair: workshop summary

    International Nuclear Information System (INIS)

    Howard-Flanders, P.

    1983-01-01

    Recombinational repair may or may not be synonymous with postreplication repair. Considerable progress has been made in the study of the relevant enzymes, particularly those from bacteria. In this workshop we focus on the recombination enzyme RecA protein. What structural changes take place in the protein and in DNA during repair. How does homologous pairing take place. How is ATP hydrolysis coupled to the stand exchange reaction and the formation of heteroduplx DNA. Turning to another enzyme needed for certain kinds of bacterial recombination, we will ask whether the purified recB protein and recC protein complement each other and are sufficient for exonuclease V activity. In higher cells, we would like to know whether sister exchanges, which occur in bacteria after uv irradiation, are also seen in animal cells

  12. [HPV DNA vaccines expressing recombinant CRT/HPV6bE7 fusion protein inhibit tumor growth and angiogenic activity].

    Science.gov (United States)

    Xu, Yan; Cheng, Hao; Zhao, Ke-Jia; Zhu, Ke-Jian; Zhang, Xing

    2007-11-01

    This paper was to study the angiogenic inhibitory effect and the potential antitumor effect of the constructed recombinant DNA vaccine CRT/HPV6bE7 in vivo. The C57BL/6 mice were vaccinated respectively with recombinant CRT/HPV6bE7 DNA plamids. The inhibitory effects on angiogenesis of generated vaccines in vivo were evaluated by a bFGF-induced angiogenesis assay using the Matrigel kit. To investigate the potential antitumor effect, the mean tumor weights, sizes and tumor appearing times were measured in C57BL/6 mice treated with HPV6bE7-expressing B16 cells. The results indicated that the recombinants CRT180/HPV6bE7 and CRT180 showed strong anti-angiogenic effects in bFGF-induced angiogenesis in vivo. Moreover, CRT180/HPV6bE7 and CRT180 DNA vaccines could significantly inhibit the tumor growth in tumor challenge experiment, and CRT180/HPV6bE7 was superior to other vaccines in delaying tumor formation time, limiting tumor size and weight in tumor protection experiment. In conclusion, recombinant CRT180/HPV6bE7 DNA could elicit a most efficient anti-angiogenic effect and inhibit tumor growth in mice inoculated with DNA vaccines. The antiangiogenic activity of CRT were suggested residing in a domain between CRT 120-180 aa.

  13. Origin of the CMS gene locus in rapeseed cybrid mitochondria: active and inactive recombination produces the complex CMS gene region in the mitochondrial genomes of Brassicaceae.

    Science.gov (United States)

    Oshima, Masao; Kikuchi, Rie; Imamura, Jun; Handa, Hirokazu

    2010-01-01

    CMS (cytoplasmic male sterile) rapeseed is produced by asymmetrical somatic cell fusion between the Brassica napus cv. Westar and the Raphanus sativus Kosena CMS line (Kosena radish). The CMS rapeseed contains a CMS gene, orf125, which is derived from Kosena radish. Our sequence analyses revealed that the orf125 region in CMS rapeseed originated from recombination between the orf125/orfB region and the nad1C/ccmFN1 region by way of a 63 bp repeat. A precise sequence comparison among the related sequences in CMS rapeseed, Kosena radish and normal rapeseed showed that the orf125 region in CMS rapeseed consisted of the Kosena orf125/orfB region and the rapeseed nad1C/ccmFN1 region, even though Kosena radish had both the orf125/orfB region and the nad1C/ccmFN1 region in its mitochondrial genome. We also identified three tandem repeat sequences in the regions surrounding orf125, including a 63 bp repeat, which were involved in several recombination events. Interestingly, differences in the recombination activity for each repeat sequence were observed, even though these sequences were located adjacent to each other in the mitochondrial genome. We report results indicating that recombination events within the mitochondrial genomes are regulated at the level of specific repeat sequences depending on the cellular environment.

  14. Production of Active Nonglycosylated Recombinant B-Chain of Type-2 Ribosome-Inactivating Protein from Viscum articulatum and Its Biological Effects on Peripheral Blood Mononuclear Cells

    Directory of Open Access Journals (Sweden)

    Tzu-Li Lu

    2011-01-01

    Full Text Available Type-2 ribosome-inactivating proteins, composed of a toxic A-chain and lectin-like B-chain, display various biological functions, including cytotoxicity and immunomodulation. We here cloned the lectin-like B-chain encoding fragment of a newly identified type-2 RIP gene, articulatin gene, from Viscum articulatum, into a bacterial expression vector to obtain nonglycosylated recombinant protein expressed in inclusion bodies. After purification and protein refolding, soluble refolded recombinant articulatin B-chain (rATB showed lectin activity specific toward galactoside moiety and was stably maintained while stored in low ionic strength solution. Despite lacking glycosylation, rATB actively bound leukocytes with preferential binding to monocytes and in vitro stimulated PBMCs to release cytokines without obvious cytotoxicity. These results implicated such a B-chain fragment as a potential immunomodulator.

  15. Administration of recombinant activated factor VII in the intensive care unit after complex cardiovascular surgery: clinical and economic outcomes.

    Science.gov (United States)

    Uber, Walter E; Toole, John M; Stroud, Martha R; Haney, Jason S; Lazarchick, John; Crawford, Fred A; Ikonomidis, John S

    2011-06-01

    Refractory bleeding after complex cardiovascular surgery often leads to increased length of stay, cost, morbidity, and mortality. Recombinant activated factor VII administered in the intensive care unit can reduce bleeding, transfusion, and surgical re-exploration. We retrospectively compared factor VII administration in the intensive care unit with reoperation for refractory bleeding after complex cardiovascular surgery. From 1501 patients who underwent cardiovascular procedures between December 2003 and September 2007, 415 high-risk patients were identified. From this cohort, 24 patients were divided into 2 groups based on whether they either received factor VII in the intensive care unit (n = 12) or underwent reoperation (n = 12) for refractory bleeding. Preoperative and postoperative data were collected to compare efficacy, safety, and economic outcomes. In-hospital survival for both groups was 100%. Factor VII was comparable with reoperation in achieving hemostasis, with both groups demonstrating decreases in chest tube output and need for blood products. Freedom from reoperation was achieved in 75% of patients receiving factor VII, whereas reoperation was effective in achieving hemostasis alone in 83.3% of patients. Prothrombin time, international normalized ratio, and median operating room time were significantly less (P factor VII. Both groups had no statistically significant differences in other efficacy, safety, or economic outcomes. Factor VII administration in the intensive care unit appears comparable with reoperation for refractory bleeding after complex cardiovascular surgical procedures and might represent an alternative to reoperation in selected patients. Future prospective, randomized controlled trials might further define its role. Copyright © 2011 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.

  16. 1H NMR structural characterization of a recombinant kringle 2 domain from human tissue-type plasminogen activator

    International Nuclear Information System (INIS)

    Byeon, I.J.L.; Llinas, M.; Kelley, R.F.

    1989-01-01

    The kringle 2 domain of human tissue-type plasminogen activator (t-PA) has been characterized via 1 H NMR spectroscopy at 300 and 620 MHz. The experiments were performed on the isolated domain obtained by expression of the 174-263 portion of t-PA in Escherichia coli. The spectrum of t-Pa kringle 2 is characteristic of a globular structure and shows overall similarity to that of the plasminogen (PGN) kringle 4. Spectral comparison with human and bovine PGN kringle 4 identified side-chain resonances from Leu 46 , which afford a fingerprint of kringle folding, and from most of the aromatic ring spin systems. Ligand-binding studies confirm that t-PA kringle 2 binds L-lysine with an association constant K a ∼ 11.9 mM -1 . The data indicate that homologous or conserved residues relative to those that compose the lysine-binding sites of PGN kringles 1 and 4 are involved in the binding of L-lysine to t-PA kringle 2. These include Tyr 36 and, within the kringle inner loop, Trp 62 , His 64 , Trp 72 , and Tyr 74 . Several labile NH protons of t-PA kringle 2 exhibit retarded H-exchange kinetics, requiring more than a week in 2 H 2 O for full deuteration in the presence of L-lysine at 37 degree C. This reveals that kringle 2 is endowed with a compact, dynamically stable conformation. Proton Overhauser experiments in 1 H 2 O, centered on well-resolved NH resonances between 9.8 and 12 ppm, identify signals arising from the His 48a imidazole NH3 proton and the three Trp indole NH1 protons. Overall, the data indicate a highly structured conformation for the recombinant t-PA kringle 2 that is closely related to that of the previously investigated PGN kringles 1, 4, and 5

  17. Embryonic stem cells deficient for Brca2 or Blm exhibit divergent genotoxic profiles that support opposing activities during homologous recombination

    Energy Technology Data Exchange (ETDEWEB)

    Marple, Teresa [Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive San Antonio, TX 78245-3207 (United States); Kim, Tae Moon [Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive San Antonio, TX 78245-3207 (United States); Hasty, Paul [Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 15355 Lambda Drive San Antonio, TX 78245-3207 (United States)]. E-mail: hastye@uthscsa.edu

    2006-12-01

    The breast cancer susceptibility protein, Brca2 and the RecQ helicase, Blm (Bloom syndrome mutated) are tumor suppressors that maintain genome integrity, at least in part, through homologous recombination (HR). Brca2 facilitates HR by interacting with Rad51 in multiple regions, the BRC motifs encoded by exon 11 and a single domain encoded by exon 27; however, the exact importance of these regions is not fully understood. Blm also interacts with Rad51 and appears to suppress HR in most circumstances; however, its yeast homologue Sgs1 facilitates HR in response to some genotoxins. To better understand the biological importance of these two proteins, we performed a genotoxic screen on mouse embryonic stem (ES) cells impaired for either Brca2 or Blm to establish their genotoxic profiles (a cellular dose-response to a wide range of agents). This is the first side-by-side comparison of these two proteins in an identical genetic background. We compared cells deleted for Brca2 exon 27 to cells reduced for Blm expression and find that the Brca2- and Blm-impaired cells exhibit genotoxic profiles that reflect opposing activities during HR. Cells deleted for Brca2 exon 27 are hypersensitive to {gamma}-radiation, streptonigrin, mitomycin C and camptothecin and mildly resistant to ICRF-193 which is similar to HR defective cells null for Rad54. By contrast, Blm-impaired cells are hypersensitive to ICRF-193, mildly resistant to camptothecin and mitomycin C and more strongly resistant to hydroxyurea. These divergent profiles support the notion that Brca2 and Blm perform opposing functions during HR in mouse ES cells.

  18. Spatially resolved thermal desorption/ionization coupled with mass spectrometry

    Science.gov (United States)

    Jesse, Stephen; Van Berkel, Gary J; Ovchinnikova, Olga S

    2013-02-26

    A system and method for sub-micron analysis of a chemical composition of a specimen are described. The method includes providing a specimen for evaluation and a thermal desorption probe, thermally desorbing an analyte from a target site of said specimen using the thermally active tip to form a gaseous analyte, ionizing the gaseous analyte to form an ionized analyte, and analyzing a chemical composition of the ionized analyte. The thermally desorbing step can include heating said thermally active tip to above 200.degree. C., and positioning the target site and the thermally active tip such that the heating step forms the gaseous analyte. The thermal desorption probe can include a thermally active tip extending from a cantilever body and an apex of the thermally active tip can have a radius of 250 nm or less.

  19. First-principles study of Frenkel pair recombination in tungsten

    International Nuclear Information System (INIS)

    Qin, Shi-Yao; Jin, Shuo; Li, Yu-Hao; Zhou, Hong-Bo; Zhang, Ying; Lu, Guang-Hong

    2017-01-01

    The recombination of one Frenkel pair in tungsten has been investigated through first-principles simulation. Two different recombination types have been identified: instantaneous and thermally activated. The small recombination barriers for thermally activated recombination cases indicate that recombination can occur easily with a slightly increased temperature. For both of the two recombination types, recombination occurs through the self-interstitial atom moving towards the vacancy. The recombination process can be direct or through replacement sequences, depending on the vertical distance between the vacancy and the 〈1 1 1〉 line of self-interstitial atom pair.

  20. Imipenem-avibactam: a novel combination for the rapid detection of carbapenemase activity in Enterobacteriaceae and Acinetobacter baumannii by matrix-assisted laser desorption ionization-time of flight mass spectrometry.

    Science.gov (United States)

    Oviaño, Marina; Bou, Germán

    2017-02-01

    In the present study, we propose a novel matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS)-based method for detecting carbapenemase-producing Enterobacteriaceae and Acinetobacter baumannii. For this, we analyzed a series of 131 isolates. Among them, a total of 115 Enterobacteriaceae: 79 of them carrying a carbapenemase enzyme (15bla KPC , 7bla NDM , 11bla IMP , 12bla VIM , and 34bla OXA-48 ) and 16 A. baumannii isolates: 15 of them carrying carbapenemases (10bla OXA-23, 2bla OXA-58, 2bla OXA-24 , and 1bla OXA-237 ). The rest of the isolates were noncarbapenemase producers and used as negative controls. The isolates were submitted to susceptibility testing using a combination of imipenem-avibactam and analysis by the MALDI-TOF Biotyper Compass software (Bruker Daltonik, Germany). The assay showed an overall sensitivity and specificity for carbapenemase detection of 98% and 100%, respectively. The combination of imipenem and avibactam displayed activity against KPC and OXA-48-producing Enterobacteriaceae and thus represents a new strategy for identifying and confirming these carbapenemases. However, the combination did not provide any benefit over A. baumannii. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. High expression of AID and active class switch recombination might account for a more aggressive disease in unmutated CLL patients: link with an activated microenvironment in CLL disease.

    Science.gov (United States)

    Palacios, Florencia; Moreno, Pilar; Morande, Pablo; Abreu, Cecilia; Correa, Agustín; Porro, Valentina; Landoni, Ana Ines; Gabus, Raul; Giordano, Mirta; Dighiero, Guillermo; Pritsch, Otto; Oppezzo, Pablo

    2010-06-03

    Interaction of chronic lymphocytic leukemia (CLL) B cells with tissue microenvironment has been suggested to favor disease progression by promoting malignant B-cell growth. Previous work has shown expression in peripheral blood (PB) of CLL B cells of activation-induced cytidine deaminase (AID) among CLL patients with an unmutated (UM) profile of immunoglobulin genes and with ongoing class switch recombination (CSR) process. Because AID expression results from interaction with activated tissue microenvironment, we speculated whether the small subset with ongoing CSR is responsible for high levels of AID expression and could be derived from this particular microenvironment. In this work, we quantified AID expression and ongoing CSR in PB of 50 CLL patients and characterized the expression of different molecules related to microenvironment interaction. Our results show that among UM patients (1) high AID expression is restricted to the subpopulation of tumoral cells ongoing CSR; (2) this small subset expresses high levels of proliferation, antiapoptotic and progression markers (Ki-67, c-myc, Bcl-2, CD49d, and CCL3/4 chemokines). Overall, this work outlines the importance of a cellular subset in PB of UM CLL patients with a poor clinical outcome, high AID levels, and ongoing CSR, whose presence might be a hallmark of a recent contact with the microenvironment.

  2. Role of teh Rad52 Amino-terminal DNA Binding Activity in DNA Strand Capture in Homologous Recombination

    DEFF Research Database (Denmark)

    Shi, Idina; Hallwyl, Swee Chuang Lim; Seong, Changhyun

    2009-01-01

    Saccharomyces cerevisiae Rad52 protein promotes homologous recombination by nucleating the Rad51 recombinase onto replication protein A-coated single-stranded DNA strands and also by directly annealing such strands. We show that the purified rad52-R70A mutant protein, with a compromised amino-ter...

  3. Inhibitory Effects of Juices Prepared from Individual Vegetables on CYP3A4 Activity in Recombinant CYP3A4 and LS180 Cells.

    Science.gov (United States)

    Tsujimoto, Masayuki; Agawa, Chie; Ueda, Shinya; Yamane, Takayoshi; Kitayama, Haruna; Terao, Aya; Fukuda, Tomoya; Minegaki, Tetsuya; Nishiguchi, Kohshi

    2017-01-01

    Human intestinal absorption and drug metabolism vary to a large extent among individuals. For example, CYP3A4 activity has large individual variation that cannot be attributed to only genetic differences. Various flavonoids in vegetables, such as kaempferol and quercetin, possess inhibitory effects, and some vegetable and fruit juices have also been found to inhibit CYP3A4 activity. Therefore, differences in daily intake of flavonoid-containing vegetables may induce individual variation in intestinal bioavailability. To identify a vegetable that strongly inhibits CYP3A4, we investigated the effects of juices, prepared from individual vegetables, on CYP3A4 activity using recombinant CYP3A4 and LS180 cells in this study. Nine vegetable juices (cabbage, Japanese radish, onion, tomato, eggplant, carrot, Chinese cabbage, green pepper, and lettuce), were prepared and recombinant CYP3A4 and LS180 cells were used for evaluation of CYP3A4 activity. Metabolism to 6β-hydroxytestosterone by recombinant CYP3A4 was strongly inhibited by cabbage, onion, and green pepper juices, and cabbage and green pepper juices significantly inhibited CYP3A4 activity in a preincubation time-dependent manner. In addition, CYP3A4 activity in LS180 cells was significantly inhibited by cabbage and onion juices. In conclusion, this study showed that juices prepared from some individual vegetables could significantly inhibit CYP3A4 activity. Therefore, variation in the daily intake of vegetables such as cabbage and onion may be one of the factors responsible for individual differences in intestinal bioavailability.

  4. Managing the SOS Response for Enhanced CRISPR-Cas-Based Recombineering in E. coli through Transient Inhibition of Host RecA Activity.

    Science.gov (United States)

    Moreb, Eirik Adim; Hoover, Benjamin; Yaseen, Adam; Valyasevi, Nisakorn; Roecker, Zoe; Menacho-Melgar, Romel; Lynch, Michael D

    2017-12-15

    Phage-derived "recombineering" methods are utilized for bacterial genome editing. Recombineering results in a heterogeneous population of modified and unmodified chromosomes, and therefore selection methods, such as CRISPR-Cas9, are required to select for edited clones. Cells can evade CRISPR-Cas-induced cell death through recA-mediated induction of the SOS response. The SOS response increases RecA dependent repair as well as mutation rates through induction of the umuDC error prone polymerase. As a result, CRISPR-Cas selection is more efficient in recA mutants. We report an approach to inhibiting the SOS response and RecA activity through the expression of a mutant dominant negative form of RecA, which incorporates into wild type RecA filaments and inhibits activity. Using a plasmid-based system in which Cas9 and recA mutants are coexpressed, we can achieve increased efficiency and consistency of CRISPR-Cas9-mediated selection and recombineering in E. coli, while reducing the induction of the SOS response. To date, this approach has been shown to be independent of recA genotype and host strain lineage. Using this system, we demonstrate increased CRISPR-Cas selection efficacy with over 10 000 guides covering the E. coli chromosome. The use of dominant negative RecA or homologues may be of broad use in bacterial CRISPR-Cas-based genome editing where the SOS pathways are present.

  5. Identification of a recombinant inulin fructotransferase (difructose dianhydride III forming) from Arthrobacter sp. 161MFSha2.1 with high specific activity and remarkable thermostability.

    Science.gov (United States)

    Wang, Xiao; Yu, Shuhuai; Zhang, Tao; Jiang, Bo; Mu, Wanmeng

    2015-04-08

    Difructose dianhydride III (DFA III) is a functional carbohydrate produced from inulin by inulin fructotransferase (IFTase, EC 4.2.2.18). In this work, an IFTase gene from Arthrobacter sp. 161MFSha2.1 was cloned and expressed in Escherachia coli. The recombinant enzyme was purified by metal affinity chromatography. It showed significant inulin hydrolysis activity, and the produced main product from inulin was determined as DFA III by nuclear magnetic resonance analysis. The molecular mass of the purified protein was calculated to be 43 and 125 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration, respectively, suggesting the native enzyme might be a homotrimer. The recombinant enzyme showed maximal activity as 2391 units/mg at pH 6.5 and 55 °C. It displayed the highest thermostability among previously reported IFTases (DFA III forming) and was stable up to 80 °C for 4 h of incubation. The smallest substrate was determined as nystose. The conversion ratio of inulin to DFA III reached 81% when 100 g/L inulin was catalyzed by 80 nM recombinant enzyme for 20 min at pH 6.5 and 55 °C. All of these data indicated that the IFTase (DFA III forming) from Arthrobacter sp. 161MFSha2.1 had great potential for industrial DFA III production.

  6. Intravenous thrombolysis with recombinant tissue plasminogen activator for ischemic stroke patients over 80 years old: the Fukuoka Stroke Registry.

    Directory of Open Access Journals (Sweden)

    Ryu Matsuo

    Full Text Available The benefit of intravenous recombinant tissue plasminogen activator (rt-PA therapy for very old patients with acute ischemic stroke remains unclear. The aim of this study was to elucidate the efficacy and safety of intravenous rt-PA therapy for patients over 80 years old.Of 13,521 stroke patients registered in the Fukuoka Stroke Registry in Japan from June 1999 to February 2013, 953 ischemic stroke patients who were over 80 years old, hospitalized within 3 h of onset, and not treated with endovascular therapy were included in this study. Among them, 153 patients were treated with intravenous rt-PA (0.6 mg/kg. For propensity score (PS-matched case-control analysis, 148 patients treated with rt-PA and 148 PS-matched patients without rt-PA therapy were selected by 1:1 matching with propensity for using rt-PA. Clinical outcomes were neurological improvement, good functional outcome at discharge, in-hospital mortality, and hemorrhagic complications (any intracranial hemorrhage [ICH], symptomatic ICH, and gastrointestinal bleeding.In the full cohort of 953 patients, rt-PA use was associated positively with neurological improvement and good functional outcome, and negatively with in-hospital mortality after adjustment for multiple confounding factors. In PS-matched case-control analysis, patients treated with rt-PA were still at lower risk for unfavorable clinical outcomes than non-treated patients (neurological improvement, odds ratio 2.67, 95% confidence interval 1.61-4.40; good functional outcome, odds ratio 2.23, 95% confidence interval 1.16-4.29; in-hospital mortality, odds ratio 0.30, 95% confidence interval 0.13-0.65. There was no significant association between rt-PA use and risk of hemorrhagic complications in the full and PS-matched cohorts.Intravenous rt-PA therapy was associated with improved clinical outcomes without significant increase in risk of hemorrhagic complications in very old patients (aged>80 years with acute ischemic stroke.

  7. Baculoviral expression and characterization of human recombinant PGCP in the form of an active mature dimer and an inactive precursor protein.

    Science.gov (United States)

    Zajc, Tajana; Suban, Dejan; Rajković, Jelena; Dolenc, Iztok

    2011-02-01

    The human-blood plasma glutamate carboxypeptidase (PGCP) is a proteinase that acts on the unsubstituted N- and C-termini of dipeptides. It has been suggested that this PGCP is involved in the release of thyroxine. Furthermore, research has suggested that its activity is up-regulated in hepatitis-C-virus-infected patients with hepatocellular carcinoma. In this study expressed human PGCP in the baculovirus expression system was produced by a Sf9 insect cell line with aim to prepare sufficient amounts of active recombinant enzyme for a subsequent biological characterization. Recombinant PGCP was expressed and secreted into the medium in the form of an inactive proenzyme. It was gradually converted into an active form in the medium after three days, with the highest expression of the active form on day six. The protein was sequentially purified by a combination of various liquid chromatographies, such as hydroxyapatite, ion exchange, and gel chromatography, and as final step with affinity chromatography on Phe-Leu-Sepharose. The human PGCP was purified as an active enzyme in the dimer form and as inactive precursor protein. The dipeptidase activity was confirmed by measuring the hydrolysis of the Ser-Met dipeptide at a slightly acidic pH. Copyright © 2010 Elsevier Inc. All rights reserved.

  8. Recombinant Activated Factor VII (Eptacog Alfa Activated, NovoSeven®) in Patients with Rare Congenital Bleeding Disorders. A Systematic Review on its Use in Surgical Procedures.

    Science.gov (United States)

    Di Minno, Matteo Nicola Dario; Ambrosino, Pasquale; Myasoedova, Veronika; Amato, Manuela; Ventre, Itala; Tremoli, Elena; Minno, Alessandro Di

    2017-01-01

    In the absence of definite guidelines in the area, we have carried a systemic review to provide a thorough overview concerning the efficacy and safety of recombinant activated factor VII (rFVIIa, NovoSeven®, Novo Nordisk A/S, Bagsværd, Denmark) in patients with Glanzmann's thrombasthenia (GT) and FVII deficiency, undergoing surgical procedures. PubMed, Web of Science, Scopus and EMBASE databases was employed for the search. Three multicenter registries were identified: the Glanzmann's Thrombasthenia Registry (GTR), the Seven Treatment Evaluation Registry (STER), and a German post-marketing surveillance registry (the WIRK study). In addition, data from 10 case-series and/or single-center experiences have been summarized. We have found that the following; perioperatively, the hemostatic effectiveness of rFVIIa was high in GT patients and in those with FVII deficiency undergoing both minor and major surgical procedures. Moreover, in all studies, rFVIIa was well tolerated. Thus, the current evidence shows an optimal perioperative safety/efficacy profile of rFVIIa in the setting of these rare bleeding disorders, and provides the rationale for further studies aimed at evaluating the optimal perioperative anti-hemorrhagic prophylaxis with rFVIIa in GT and in FVII deficient patients. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Recombinant AAV-mediated in vivo long-term expression and antitumour activity of an anti-ganglioside GM3(Neu5Gc) antibody.

    Science.gov (United States)

    Piperno, G M; López-Requena, A; Predonzani, A; Dorvignit, D; Labrada, M; Zentilin, L; Burrone, O R; Cesco-Gaspere, M

    2015-12-01

    The ganglioside GM3(Neu5Gc) has gained increasing attention as therapeutic target because of its selective expression in various human tumours, such as melanoma, breast and lung cancer. 14F7 is a mouse IgG1 with specific reactivity to GM3(Neu5Gc)-positive tumours. The therapeutic activity of 14F7 has also been demonstrated in vivo, through its repetitive passive administration in tumour-bearing animals. In this work we used an alternative strategy to deliver recombinant 14F7 in vivo and analysed the therapeutic efficacy of this approach. We engineered a recombinant adeno-associated vector to direct the expression of secretable recombinant 14F7 in BALB/c animals. A single administration of the rAAV induced efficient production and secretion of the antibody in the bloodstream, with an expression level reaching plateau at ∼3 weeks after injection and persisting for almost a year. Strikingly, upon challenge with GM3(Neu5Gc)-positive X63-AG8.653 myeloma cells, tumour development was significantly delayed in animals treated with rAAV-14F7 with respect to animals treated with a control rAAV codifying for an irrelevant antibody. Finally, no significant differences in survival proportion were detected in animals injected with rAAV-14F7 or treated by standard administration of repetitive doses of purified monoclonal antibody 14F7.

  10. Expression levels of chaperones influence biotransformation activity of recombinant Escherichia coli expressing Micrococcus luteus alcohol dehydrogenase and Pseudomonas putida Baeyer-Villiger monooxygenase.

    Science.gov (United States)

    Baek, A-Hyong; Jeon, Eun-Yeong; Lee, Sun-Mee; Park, Jin-Byung

    2015-05-01

    We demonstrated for the first time that the archaeal chaperones (i.e., γ-prefoldin and thermosome) can stabilize enzyme activity in vivo. Ricinoleic acid biotransformation activity of recombinant Escherichia coli expressing Micrococcus luteus alcohol dehydrogenase and the Pseudomonas putida KT2440 Baeyer-Villiger monooxygenase improved significantly with co-expression of γ-prefoldin or recombinant themosome originating from the deep-sea hyperthermophile archaea Methanocaldococcus jannaschii. Furthermore, the degree of enhanced activity was dependent on the expression levels of the chaperones. For example, whole-cell biotransformation activity was highest at 12 µmol/g dry cells/min when γ-prefoldin expression level was approximately 46% of the theoretical maximum. This value was approximately two-fold greater than that in E. coli, where the γ-prefoldin expression level was zero or set to the theoretical maximum. Therefore, it was assumed that the expression levels of chaperones must be optimized to achieve maximum biotransformation activity in whole-cell biocatalysts. © 2014 Wiley Periodicals, Inc.

  11. New subtypes and genetic recombination in HIV type 1-infecting patients with highly active antiretroviral therapy in Peru (2008-2010).

    Science.gov (United States)

    Yabar, Carlos Augusto; Acuña, Maribel; Gazzo, Cecilia; Salinas, Gabriela; Cárdenas, Fanny; Valverde, Ada; Romero, Soledad

    2012-12-01

    HIV-1 subtype B is the most frequent strain in Peru. However, there is no available data about the genetic diversity of HIV-infected patients receiving highly active antiretroviral therapy (HAART) here. A group of 267 patients in the Peruvian National Treatment Program with virologic failure were tested for genotypic evidence of HIV drug resistance at the Instituto Nacional de Salud (INS) of Peru between March 2008 and December 2010. Viral RNA was extracted from plasma and the segments of the protease (PR) and reverse transcriptase (RT) genes were amplified by reverse transcriptase polymerase chain reaction (RT-PCR), purified, and fully sequenced. Consensus sequences were submitted to the HIVdb Genotypic Resistance Interpretation Algorithm Database from Stanford University, and then aligned using Clustal X v.2.0 to generate a phylogenetic tree using the maximum likelihood method. Intrasubtype and intersubtype recombination analyses were performed using the SCUEAL program (Subtype Classification by Evolutionary ALgo-rithms). A total of 245 samples (91%) were successfully genotyped. The analysis obtained from the HIVdb program showed 81.5% resistance cases (n=198). The phylogenetic analysis revealed that subtype B was predominant in the population (98.8%), except for new cases of A, C, and H subtypes (n=4). Of these cases, only subtype C was imported. Likewise, recombination analysis revealed nine intersubtype and 20 intrasubtype recombinant cases. This is the first report of the presence of HIV-1 subtypes C and H in Peru. The introduction of new subtypes and circulating recombinants forms can make it difficult to distinguish resistance profiles in patients and consequently affect future treatment strategies against HIV in this country.

  12. Recombinant protein expression of Moringa oleifera lectin in methylotrophic yeast as active coagulant for sustainable high turbid water treatment.

    Science.gov (United States)

    Abd Wahid, Muhamad Azhar; Megat Mohd Noor, Megat Johari; Goto, Masafumi; Sugiura, Norio; Othman, Nor'azizi; Zakaria, Zuriati; Ahmad Mohammed, Thamer; Jusoh, Ahmad; Hara, Hirofumi

    2017-08-01

    The natural coagulant Moringa oleifera lectin (MoL) as cationic protein is a promising candidate in coagulation process of water treatment plant. Introducing the gene encoding MoL into a host, Pichia pastoris, to secrete soluble recombinant protein is assessed in this study. Initial screening using PCR confirmed the insertion of MoL gene, and SDS-PAGE analysis detected the MoL protein at 8 kDa. Cultured optimization showed the highest MoL protein at 520 mg/L was observed at 28 °C for 144 h of culturing by induction in 1% methanol. Approximately, 0.40 mg/mL of recombinant MoL protein showed 95 ± 2% turbidity removal of 1% kaolin suspension. In 0.1% kaolin suspension, the concentration of MoL at 10 μg/mL exhibits the highest turbidity reduction at 68 ± 1%. Thus, recombinant MoL protein from P. pastoris is an effective coagulant for water treatment.

  13. Hydrogen desorption kinetics from zirconium hydride and zirconium metal in vacuum

    International Nuclear Information System (INIS)

    Hu, Xunxiang; Terrani, Kurt A.; Wirth, Brian D.

    2014-01-01

    The kinetics of hydrogen desorption from zirconium hydride is important in many nuclear design and safety applications. In this paper, a coordinated experimental and modeling study has been used to explicitly demonstrate the applicability of existing kinetic theories for hydrogen desorption from zirconium hydride and α-zirconium. A static synthesis method was used to produce δ-zirconium hydride, and the crystallographic phases of the zirconium hydride were confirmed by X-ray diffraction (XRD). Three obvious stages, involving δ-zirconium hydride, a two-phase region, and α-zirconium, were observed in the hydrogen desorption spectra of two zirconium hydride specimens with H/Zr ratios of 1.62 and 1.64, respectively, which were obtained using thermal desorption spectroscopy (TDS). A continuous, one-dimensional, two-phase moving boundary model, coupled with the zero- and second-order kinetics of hydrogen desorption from δ-zirconium hydride and α-zirconium, respectively, has been developed to reproduce the TDS experimental results. A comparison of the modeling predictions with the experimental results indicates that a zero-order kinetic model is valid for description of hydrogen flux away from the δ-hydride phase, and that a second-order kinetic model works well for hydrogen desorption from α-Zr if the activation energy of desorption is optimized to be 70% of the value reported in the literature

  14. Recombinant production of a chimeric antimicrobial peptide in E. coli and assessment of its activity against some avian clinically isolated pathogens.

    Science.gov (United States)

    Tanhaiean, Abass; Azghandi, Marjan; Razmyar, Jamshid; Mohammadi, Elyas; Sekhavati, Mohammad Hadi

    2018-06-08

    Over the last decades, poultry industry faced to the rapid emergence of multidrug-resistant bacteria as a global concern. Antimicrobial peptide (AMPs) known as potential antibiotic alternative and were considered as a new antimicrobial agent. Current methods of production and purification of AMPs have several limitations such as: costly, time-consuming and killing the producing host cells in recombinant form. In the present study, a chimeric peptide derived from camel lactoferrin was produced in Escherichia coli periplasmic space using a pET-based expression system and its antibacterial activity was determined on some avian pathogens in vitro. A carboxy-terminal polyhistidine tag was used for purification by Ni 2+ affinity chromatography with an average yield of 0.42 g/L. The His-tagged chimeric peptide showed different range of antimicrobial activity against clinically isolated avian pathogens with low chicken blood hemolysis activity and high serum stability. Overall, the results of this investigation showed the recombinant chimeric peptide was successfully expressed in pET-based expression system and could be considered as a proper alternative for some currently used antibiotics in poultry industry and drugs veterinary medicine. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Inhibition of protease activity by antisense RNA improves recombinant protein production in Nicotiana tabacum cv. Bright Yellow 2 (BY-2) suspension cells.

    Science.gov (United States)

    Mandal, Manoj K; Fischer, Rainer; Schillberg, Stefan; Schiermeyer, Andreas

    2014-08-01

    Recombinant proteins produced in plant suspension cultures are often degraded by endogenous plant proteases when secreted into the medium, resulting in low yields. To generate protease-deficient tobacco BY-2 cell lines and to retrieve the sequence information, we cloned four different protease cDNAs from tobacco BY-2 cells (NtAP, NtCP, NtMMP1, and NtSP), which represent the major catalytic classes. The simultaneous expression of antisense RNAs against these endogenous proteases led to the establishment of cell lines with reduced levels of endogenous protease expression and activity at late stages of the cultivation cycle. One of the cell lines showing reduced proteolytic activity in the culture medium was selected for the expression of the recombinant full-length IgG1(κ) antibody 2F5, recognizing the gp41 surface protein of HIV-1. This cell line showed significantly reduced degradation of the 2F5 heavy chain, resulting in four-fold higher accumulation of the intact antibody heavy chain when compared to transformed wild type cells expressing the same antibody. N-terminal sequencing data revealed that the antibody has two cleavage sites within the CDR-H3 and one site at the end of the H4-framework region. These cleavage sites are found to be vulnerable to serine proteases. The data provide a basis for further improvement of plant cells for the production of recombinant proteins in plant cell suspension cultures. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Recombinant activated factor VII in the treatment of bleeds and for the prevention of surgery-related bleeding in congenital haemophilia with inhibitors.

    Science.gov (United States)

    Santagostino, Elena; Escobar, Miguel; Ozelo, Margareth; Solimeno, Luigi; Arkhammar, Per; Lee, Hye Youn; Rosu, Gabriela; Giangrande, Paul

    2015-06-01

    The availability of recombinant activated factor VII (rFVIIa, eptacog alfa activated) has greatly advanced the care of patients with haemophilia A or B who have developed inhibitors against the infused replacement factor. Recombinant FVIIa is licensed for the on-demand treatment of bleeding episodes and the prevention of bleeding in surgery or invasive procedures in patients with congenital haemophilia with inhibitors. This article attempts to review in detail the extensive evidence of rFVIIa in congenital haemophilia patients with inhibitors. Patients with acute bleeding episodes are best treated on demand at home, to achieve the short- and long-term benefits of rapid bleed control. Key prospective studies have shown that rFVIIa achieves consistently high efficacy rates in the management of acute (including joint) bleeds in inhibitor patients in the home treatment setting. Substantial post-approval data from key registries also support the on-demand efficacy profile of rFVIIa established by the prospective clinical trials. The availability of rFVIIa has allowed major surgery to become a reality for inhibitor patients. Studies in key surgery, including orthopaedic procedures, have found that rFVIIa provides consistently high efficacy rates. Importantly, the wealth of data does not raise any unexpected safety concerns surrounding rFVIIa use; this is likely because rFVIIa is a recombinant product with a localised mechanism of action at the site of vascular injury. In summary, rFVIIa is established as an effective and well-tolerated first-line treatment for on-demand bleeding control and bleed prevention during minor and major (including elective orthopaedic) surgery in inhibitor patients. Use of rFVIIa has been a major step towards narrowing the gap in outcomes between inhibitor patients and non-inhibitor patients. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. The Absorption-Desorption of Hydrogen by 1.5 g Depleted Uranium

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sunmi; Paek, Seungwoo; Lee, Minsoo; Kim, Si-Hyung; Kim, Kwang-Rag; Ahn, Do-Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Sohn, Soon Hwan; Song, Kyu Min [Korea Electric Power Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    The form of metal tritides is one of the most popular methods for the storage of hydrogen isotopes. Particularly when metal is in a powder form, the storage capacity of hydrogen isotopes become the maximum value. Here, a 1.5g depleted uranium metal was decrepitated into a powder upon an absorption and desorption of hydrogen gas. The conditions for an activation, absorption-desorption of the hydrogen were defined.

  18. The Absorption-Desorption of Hydrogen by 1.5 g Depleted Uranium

    International Nuclear Information System (INIS)

    Kim, Sunmi; Paek, Seungwoo; Lee, Minsoo; Kim, Si-Hyung; Kim, Kwang-Rag; Ahn, Do-Hee; Sohn, Soon Hwan; Song, Kyu Min

    2008-01-01

    The form of metal tritides is one of the most popular methods for the storage of hydrogen isotopes. Particularly when metal is in a powder form, the storage capacity of hydrogen isotopes become the maximum value. Here, a 1.5g depleted uranium metal was decrepitated into a powder upon an absorption and desorption of hydrogen gas. The conditions for an activation, absorption-desorption of the hydrogen were defined

  19. Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults.

    Science.gov (United States)

    Szpakowski, Piotr; Biet, Franck; Locht, Camille; Paszkiewicz, Małgorzata; Rudnicka, Wiesława; Druszczyńska, Magdalena; Allain, Fabrice; Fol, Marek; Pestel, Joël; Kowalewicz-Kulbat, Magdalena

    2015-01-01

    Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG), the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18) and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4(+) T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

  20. Dendritic Cell Activity Driven by Recombinant Mycobacterium bovis BCG Producing Human IL-18, in Healthy BCG Vaccinated Adults

    Directory of Open Access Journals (Sweden)

    Piotr Szpakowski

    2015-01-01

    Full Text Available Tuberculosis remains an enormous global burden, despite wide vaccination coverage with the Bacillus Calmette-Guérin (BCG, the only vaccine available against this disease, indicating that BCG-driven immunity is insufficient to protect the human population against tuberculosis. In this study we constructed recombinant BCG producing human IL-18 (rBCGhIL-18 and investigated whether human IL-18 produced by rBCGhIL-18 modulates DC functions and enhances Th1 responses to mycobacterial antigens in humans. We found that the costimulatory CD86 and CD80 molecules were significantly upregulated on rBCGhIL-18-infected DCs, whereas the stimulation of DCs with nonrecombinant BCG was less effective. In contrast, both BCG strains decreased the DC-SIGN expression on human DCs. The rBCGhIL-18 increased IL-23, IL-10, and IP-10 production by DCs to a greater extent than nonrecombinant BCG. In a coculture system of CD4+ T cells and loaded DCs, rBCGhIL-18 favoured strong IFN-γ but also IL-10 production by naive T cells but not by memory T cells. This was much less the case for nonrecombinant BCG. Thus the expression of IL-18 by recombinant BCG increases IL-23, IP-10, and IL-10 expression by human DCs and enhances their ability to induce IFN-γ and IL-10 expression by naive T cells, without affecting the maturation phenotype of the DCs.

  1. Enhancement of 2,3-butanediol production from Jerusalem artichoke tuber extract by a recombinant Bacillus sp. strain BRC1 with increased inulinase activity.

    Science.gov (United States)

    Park, Jang Min; Oh, Baek-Rock; Kang, In Yeong; Heo, Sun-Yeon; Seo, Jeong-Woo; Park, Seung-Moon; Hong, Won-Kyung; Kim, Chul Ho

    2017-07-01

    A Bacillus sp. strain named BRC1 is capable of producing 2,3-butanediol (2,3-BD) using hydrolysates of the Jerusalem artichoke tuber (JAT), a rich source of the fructose polymer inulin. To enhance 2,3-BD production, we undertook an extensive analysis of the Bacillus sp. BRC1 genome, identifying a putative gene (sacC) encoding a fructan hydrolysis enzyme and characterizing the activity of the resulting recombinant protein expressed in and purified from Escherichia coli. Introduction of the sacC gene into Bacillus sp. BRC1 using an expression vector increased enzymatic activity more than twofold. Consistent with this increased enzyme expression, 2,3-BD production from JAT was also increased from 3.98 to 8.10 g L -1 . Fed-batch fermentation of the recombinant strain produced a maximal level of 2,3-BD production of 28.6 g L -1 , showing a high theoretical yield of 92.3%.

  2. Recombinant Collagenlike Proteins

    Science.gov (United States)

    Fertala, Andzej

    2007-01-01

    A group of collagenlike recombinant proteins containing high densities of biologically active sites has been invented. The method used to express these proteins is similar to a method of expressing recombinant procollagens and collagens described in U. S. Patent 5,593,859, "Synthesis of human procollagens and collagens in recombinant DNA systems." Customized collagenous proteins are needed for biomedical applications. In particular, fibrillar collagens are attractive for production of matrices needed for tissue engineering and drug delivery. Prior to this invention, there was no way of producing customized collagenous proteins for these and other applications. Heretofore, collagenous proteins have been produced by use of such biological systems as yeasts, bacteria, and transgenic animals and plants. These products are normal collagens that can also be extracted from such sources as tendons, bones, and hides. These products cannot be made to consist only of biologically active, specific amino acid sequences that may be needed for specific applications. Prior to this invention, it had been established that fibrillar collagens consist of domains that are responsible for such processes as interaction with cells, binding of growth factors, and interaction with a number of structural proteins present in the extracellular matrix. A normal collagen consists of a sequence of domains that can be represented by a corresponding sequence of labels, e.g., D1D2D3D4. A collagenlike protein of the present invention contains regions of collagen II that contain multiples of a single domain (e.g., D1D1D1D1 or D4D4D4D4) chosen for its specific biological activity. By virtue of the multiplicity of the chosen domain, the density of sites having that specific biological activity is greater than it is in a normal collagen. A collagenlike protein according to this invention can thus be made to have properties that are necessary for tissue engineering.

  3. Catalitic effect of Co on hydrogen desorption form nanostucturated magnesium hydride

    Directory of Open Access Journals (Sweden)

    Matović Ljiljana Lj.

    2008-01-01

    Full Text Available To study the influence of 3d transition metal addition on desorption kinetics of MgH2 ball milling of MgH2-Co blends was performed under Ar. Microstructural and morphological characterization, performed by XRD and SEM, show a huge correlation with thermal stability and hydrogen desorption properties investigated by DSC. A complex desorption behavior is correlated with the dispersion of the metal additive particles on hydride matrix. The activation energy for H2 desorption from MgH2-Co composite was calculated from both non-isothermal and isothermal methods to be 130 kJ/mol which means that mutually diffusion and nucleation and growth of new phase control the dehydration process.

  4. A successful strategy for the recovering of active P21, an insoluble recombinant protein of Trypanosoma cruzi

    Science.gov (United States)

    Santos, Marlus Alves Dos; Teixeira, Francesco Brugnera; Moreira, Heline Hellen Teixeira; Rodrigues, Adele Aud; Machado, Fabrício Castro; Clemente, Tatiana Mordente; Brigido, Paula Cristina; Silva, Rebecca Tavares E.; Purcino, Cecílio; Gomes, Rafael Gonçalves Barbosa; Bahia, Diana; Mortara, Renato Arruda; Munte, Claudia Elisabeth; Horjales, Eduardo; da Silva, Claudio Vieira

    2014-03-01

    Structural studies of proteins normally require large quantities of pure material that can only be obtained through heterologous expression systems and recombinant technique. In these procedures, large amounts of expressed protein are often found in the insoluble fraction, making protein purification from the soluble fraction inefficient, laborious, and costly. Usually, protein refolding is avoided due to a lack of experimental assays that can validate correct folding and that can compare the conformational population to that of the soluble fraction. Herein, we propose a validation method using simple and rapid 1D 1H nuclear magnetic resonance (NMR) spectra that can efficiently compare protein samples, including individual information of the environment of each proton in the structure.

  5. Effect of hydrophilicity of carbon nanotube arrays on the release rate and activity of recombinant human bone morphogenetic protein-2

    Energy Technology Data Exchange (ETDEWEB)

    Han Zhaojun; Ostrikov, Kostya [Plasma Nanoscience Centre Australia (PNCA), CSIRO Materials Science and Engineering, Lindfield, New South Wales 2070 (Australia); Tan, Cher Ming; Tay, Beng Kang [School of Electrical and Electronic Engineering, Nanyang Technological University, 639798 (Singapore); Peel, Sean A F, E-mail: zhaojun.han@csiro.au [Department of Dentistry, University of Toronto, Toronto, ON, M5G 1G6 (Canada)

    2011-07-22

    Novel nanostructures such as vertically aligned carbon nanotube (CNT) arrays have received increasing interest as drug delivery carriers. In the present study, two CNT arrays with extreme surface wettabilities are fabricated and their effects on the release of recombinant human bone morphogenetic protein-2 (rhBMP-2) are investigated. It is found that the superhydrophilic arrays retained a larger amount of rhBMP-2 than the superhydrophobic ones. Further use of a poloxamer diffusion layer delayed the initial burst and resulted in a greater total amount of rhBMP-2 released from both surfaces. In addition, rhBMP-2 bound to the superhydrophilic CNT arrays remained bioactive while they denatured on the superhydrophobic surfaces. These results are related to the combined effects of rhBMP-2 molecules interacting with poloxamer and the surface, which could be essential in the development of advanced carriers with tailored surface functionalities.

  6. Dependence of Immunoglobulin Class Switch Recombination in B Cells on Vesicular Release of ATP and CD73 Ectonucleotidase Activity

    Directory of Open Access Journals (Sweden)

    Francesca Schena

    2013-06-01

    Full Text Available Immunoglobulin (Ig isotype diversification by class switch recombination (CSR is an essential process for mounting a protective humoral immune response. Ig CSR deficiencies in humans can result from an intrinsic B cell defect; however, most of these deficiencies are still molecularly undefined and diagnosed as common variable immunodeficiency (CVID. Here, we show that extracellular adenosine critically contributes to CSR in human naive and IgM memory B cells. In these cells, coordinate stimulation of B cell receptor and toll-like receptors results in the release of ATP stored in Ca2+-sensitive secretory vesicles. Plasma membrane ectonucleoside triphosphate diphosphohydrolase 1 CD39 and ecto-5′-nucleotidase CD73 hydrolyze ATP to adenosine, which induces CSR in B cells in an autonomous fashion. Notably, CVID patients with impaired class-switched antibody responses are selectively deficient in CD73 expression in B cells, suggesting that CD73-dependent adenosine generation contributes to the pathogenesis of this disease.

  7. Recombination efficiency of molecular hydrogen on interstellar grains - II: A numerical study

    International Nuclear Information System (INIS)

    Chakrabarti, S.K.; Ankan, Das; Kinsuk, Acharyya; Sonali, Chakrabarti

    2006-05-01

    Knowledge of the recombination time on the grain surfaces has been a major obstacle in deciding the production rate of molecular hydrogen and other molecules in the interstellar medium. We present a numerical study to compute this time for molecular hydrogen for various cloud and grain parameters. We also find the time dependence, particularly when a grain is freshly injected into the system. Apart from the fact that the recombination times seem to be functions of the grain parameters such as the activation barrier energy, temperature etc., our result also shows the dependence on the number of sites in the grain S and the effective accretion rate per site a s of atomic hydrogen. To put simply the average time that a pair of atomic hydrogens will take to produce one molecular hydrogen depends on how heavily the grain is already populated by atomic and molecular hydrogens and how fast the hopping and desorption times are. We show that if we write the average recombination time as T r ∼ S α /A H , where, A H is the hopping rate, then α could be much greater than 1 for all astrophysically relevant accretion rates. Thus the average formation rate of H 2 is also dependent on the grain parameters, temperature and the accretion rate. We believe that our results will affect the overall rate of the formation of complex molecules such as methanol which requires successive hydrogenation on the grain surfaces in the interstellar medium. (author)

  8. Critical appraisal of the role of recombinant activated factor VII in the treatment of hemophilia patients with inhibitors

    Directory of Open Access Journals (Sweden)

    Ampaiwan Chuansumrit

    2010-03-01

    Full Text Available Ampaiwan Chuansumrit1, Pantep Angchaisuksiri2, Nongnuch Sirachainan11Departments of Pediatrics and 2Medicine, Faculty of Medicine, Ramathibodi Hospital, Mahidol University,  Bangkok, ThailandAbstract: Hemophilia patients with inhibitors faced the constraint of inadequate treatment for several years before the era of recombinant factor VIIa (rFVII. Initially, rFVIIa was used in the compassionate-use programs. After a worldwide license was issued, more than 1.5 million doses were administered. Bleeding of joints and muscles was controlled effectively by means of an early home treatment program, with either a standard dose of 90 μg/kg every 2 to 3 hours for a few doses or a single dose of 270 μg/kg. For more serious bleeding episodes or minor surgery, an initial dose of 90 μg/kg was given every 2 hours for 24 to 48 hours followed by increased intervals of 3 to 6 hours according to the severity of bleeding and efficacy of bleeding control. In cases of major surgery such as orthopedic procedures, the same regimen can be applied except for a higher initial dose of 120 to 180 μg/kg. However, increasing the dose should be considered if there are unexpected bleeding complications since the half-life and clearance of rFVIIa differ between individuals. In addition, prophylaxis is administered to a small number of patients. Finally, the reported thromboembolic events found in hemophilia patients with inhibitors receiving rFVIIa are extremely low, much less than 1%.Keywords: bleeding disorder, hemophilia, inhibitor, NovoSeven, recombinant factor VIIa

  9. Surface Structures and Thermal Desorption Behaviors of Cyclopentanethiol Self-Assembled Monolayers on Au(111)

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Hun Gu; Kim, You Young; Park, Tae Sun; Noh, Jae Geun [Hanyang University, Seoul (Korea, Republic of); Park, Joon B. [Chonbuk National University, Jeonju (Korea, Republic of); Ito, Eisuke; Hara, Masahiko [RIKEN-HYU Collaboration Center, Saitama (Japan)

    2011-04-15

    The surface structures, adsorption conditions, and thermal desorption behaviors of cyclopentanethiol (CPT) self-assembled monolayers (SAMs) on Au(111) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy (TDS). STM imaging revealed that although the adsorption of CPT on Au(111) at room temperature generates disordered SAMs, CPT molecules at 50 .deg. C formed well-ordered SAMs with a (2√3 x √5)R41{sup .}deg. packing structure. XPS measurements showed that CPT SAMs at room temperature were formed via chemical reactions between the sulfur atoms and gold surfaces. TDS measurements showed two dominant TD peaks for the decomposed fragments (C{sub 5}H{sub 9} {sup +}, m/e = 69) generated via C-S bond cleavage and the parent molecular species (C{sub 5}H{sub 9}SH{sup +}, m/e = 102) derived from a recombination of the chemisorbed thiolates and hydrogen atoms near 440 K. Interestingly, dimerization of sulfur atoms in n-alkanethiol SAMs usually occurs during thermal desorption and the same reaction did not happen for CPT SAMs, which may be due to the steric hindrance of cyclic rings of the CPT molecules. In this study, we demonstrated that the alicyclic ring of organic thiols strongly affected the surface structure and thermal desorption behavior of SAMs, thus providing a good method for controlling chemical and physical properties of organic thiol SAMs.

  10. Surface Structures and Thermal Desorption Behaviors of Cyclopentanethiol Self-Assembled Monolayers on Au(111)

    International Nuclear Information System (INIS)

    Kang, Hun Gu; Kim, You Young; Park, Tae Sun; Noh, Jae Geun; Park, Joon B.; Ito, Eisuke; Hara, Masahiko

    2011-01-01

    The surface structures, adsorption conditions, and thermal desorption behaviors of cyclopentanethiol (CPT) self-assembled monolayers (SAMs) on Au(111) were investigated by scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), and thermal desorption spectroscopy (TDS). STM imaging revealed that although the adsorption of CPT on Au(111) at room temperature generates disordered SAMs, CPT molecules at 50 .deg. C formed well-ordered SAMs with a (2√3 x √5)R41".deg. packing structure. XPS measurements showed that CPT SAMs at room temperature were formed via chemical reactions between the sulfur atoms and gold surfaces. TDS measurements showed two dominant TD peaks for the decomposed fragments (C_5H_9 "+, m/e = 69) generated via C-S bond cleavage and the parent molecular species (C_5H_9SH"+, m/e = 102) derived from a recombination of the chemisorbed thiolates and hydrogen atoms near 440 K. Interestingly, dimerization of sulfur atoms in n-alkanethiol SAMs usually occurs during thermal desorption and the same reaction did not happen for CPT SAMs, which may be due to the steric hindrance of cyclic rings of the CPT molecules. In this study, we demonstrated that the alicyclic ring of organic thiols strongly affected the surface structure and thermal desorption behavior of SAMs, thus providing a good method for controlling chemical and physical properties of organic thiol SAMs

  11. Identification, Characterization, and Recombinant Expression of Epidermicin NI01, a Novel Unmodified Bacteriocin Produced by Staphylococcus epidermidis That Displays Potent Activity against Staphylococci

    Science.gov (United States)

    Sandiford, Stephanie

    2012-01-01

    We describe the discovery, purification, characterization, and expression of an antimicrobial peptide, epidermicin NI01, which is an unmodified bacteriocin produced by Staphylococcus epidermidis strain 224. It is a highly cationic, hydrophobic, plasmid-encoded peptide that exhibits potent antimicrobial activity toward a wide range of pathogenic Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA), enterococci, and biofilm-forming S. epidermidis strains. Purification of the peptide was achieved using a combination of hydrophobic interaction, cation exchange, and high-performance liquid chromatography (HPLC). Matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) analysis yielded a molecular mass of 6,074 Da, and partial sequence data of the peptide were elucidated using a combination of tandem mass spectrometry (MS/MS) and de novo sequencing. The draft genome sequence of the producing strain was obtained using 454 pyrosequencing technology, thus enabling the identification of the structural gene using the de novo peptide sequence data previously obtained. Epidermicin NI01 contains 51 residues with four tryptophan and nine lysine residues, and the sequence showed approximately 50% identity to peptides lacticin Z, lacticin Q, and aureocin A53, all of which belong to a new family of unmodified type II-like bacteriocins. The peptide is active in the nanomolar range against S. epidermidis, MRSA isolates, and vancomycin-resistant enterococci. Other unique features displayed by epidermicin include a high degree of protease stability and the ability to retain antimicrobial activity over a pH range of 2 to 10, and exposure to the peptide does not result in development of resistance in susceptible isolates. In this study we also show the structural gene alone can be cloned into Escherichia coli strain BL21(DE3), and expression yields active peptide. PMID:22155816

  12. Understanding Recombination.

    Science.gov (United States)

    Zimmerman, Ira

    2003-01-01

    Describes a science activity on the importance of meiosis for variability. Uses a coin flip to demonstrate the random arrangement of genetic materials and explains how this results in zygotes with a new DNA combination. (YDS)

  13. Recombination Suppression in PbS Quantum Dot Heterojunction Solar Cells by Energy-Level Alignment in the Quantum Dot Active Layers.

    Science.gov (United States)

    Ding, Chao; Zhang, Yaohong; Liu, Feng; Nakazawa, Naoki; Huang, Qingxun; Hayase, Shuzi; Ogomi, Yuhei; Toyoda, Taro; Wang, Ruixiang; Shen, Qing

    2017-09-22

    Using spatial energy-level gradient engineering with quantum dots (QDs) of different sizes to increase the generated carrier collection at the junction of a QD heterojunction solar cell (QDHSC) is a hopeful route for improving the energy-conversion efficiency. However, the results of current related research have shown that a variable band-gap structure in a QDHSC will create an appreciable increase, not in the illumination current density, but rather in the fill factor. In addition, there are a lack of studies on the mechanism of the effect of these graded structures on the photovoltaic performance of QDHSCs. This study presents the development of air atmosphere solution-processed TiO 2 /PbS QDs/Au QDHSCs by engineering the energy-level alignment (ELA) of the active layer via the use of a sorted order of differently sized QD layers (four QD sizes). In comparison to the ungraded device (without the ELA), the optimized graded architecture (containing the ELA) solar cells exhibited a great increase (21.4%) in short-circuit current density (J sc ). As a result, a J sc value greater than 30 mA/cm 2 has been realized in planar, thinner absorption layer (∼300 nm) PbS QDHSCs, and the open-circuit voltage (V oc ) and power-conversion efficiency (PCE) were also improved. Through characterization by the light intensity dependences of the J sc and V oc and transient photovoltage decay, we find that (i) the ELA structure, serving as an electron-blocking layer, reduces the interfacial recombination at the PbS/anode interface, and (ii) the ELA structure can drive more carriers toward the desirable collection electrode, and the additional carriers can fill the trap states, reducing the trap-assisted recombination in the PbS QDHSCs. This work has clearly elucidated the mechanism of the recombination suppression in the graded QDHSCs and demonstrated the effects of ELA structure on the improvement of J sc . The charge recombination mechanisms characterized in this work would be

  14. Modelling of discrete TDS-spectrum of hydrogen desorption

    Science.gov (United States)

    Rodchenkova, Natalia I.; Zaika, Yury V.

    2015-12-01

    High concentration of hydrogen in metal leads to hydrogen embrittlement. One of the methods to evaluate the hydrogen content is the method of thermal desorption spectroscopy (TDS). As the sample is heated under vacuumization, atomic hydrogen diffuses inside the bulk and is desorbed from the surface in the molecular form. The extraction curve (measured by a mass-spectrometric analyzer) is recorded. In experiments with monotonous external heating it is observed that background hydrogen fluxes from the extractor walls and fluxes from the sample cannot be reliably distinguished. Thus, the extraction curve is doubtful. Therefore, in this case experimenters use discrete TDS-spectrum: the sample is removed from the analytical part of the device for the specified time interval, and external temperature is then increased stepwise. The paper is devoted to the mathematical modelling and simulation of experimental studies. In the corresponding boundary-value problem with nonlinear dynamic boundary conditions physical- chemical processes in the bulk and on the surface are taken into account: heating of the sample, diffusion in the bulk, hydrogen capture by defects, penetration from the bulk to the surface and desorption. The model aimed to analyze the dynamics of hydrogen concentrations without preliminary artificial sample saturation. Numerical modelling allows to choose the point on the extraction curve that corresponds to the initial quantity of the surface hydrogen, to estimate the values of the activation energies of diffusion, desorption, parameters of reversible capture and hydride phase decomposition.

  15. New perspectives in vacuum high voltage insulation. II. Gas desorption

    CERN Document Server

    Diamond, W T

    1998-01-01

    An examination has been made of gas desorption from unbaked electrodes of copper, niobium, aluminum, and titanium subjected to high voltage in vacuum. It has been shown that the gas is composed of water vapor, carbon monoxide, and carbon dioxide, the usual components of vacuum outgassing, plus an increased yield of hydrogen and light hydrocarbons. The gas desorption was driven by anode conditioning as the voltage was increased between the electrodes. The gas is often desorbed as microdischarges-pulses of a few to hundreds of microseconds-and less frequently in a more continuous manner without the obvious pulsed structure characteristic of microdischarge activity. The quantity of gas released was equivalent to many monolayers and consisted mostly of neutral molecules with an ionic component of a few percent. A very significant observation was that the gas desorption was more dependent on the total voltage between the electrodes than on the electric field. It was not triggered by field-emitted electrons but oft...

  16. Modelling of discrete TDS-spectrum of hydrogen desorption

    International Nuclear Information System (INIS)

    Rodchenkova, Natalia I; Zaika, Yury V

    2015-01-01

    High concentration of hydrogen in metal leads to hydrogen embrittlement. One of the methods to evaluate the hydrogen content is the method of thermal desorption spectroscopy (TDS). As the sample is heated under vacuumization, atomic hydrogen diffuses inside the bulk and is desorbed from the surface in the molecular form. The extraction curve (measured by a mass-spectrometric analyzer) is recorded. In experiments with monotonous external heating it is observed that background hydrogen fluxes from the extractor walls and fluxes from the sample cannot be reliably distinguished. Thus, the extraction curve is doubtful. Therefore, in this case experimenters use discrete TDS-spectrum: the sample is removed from the analytical part of the device for the specified time interval, and external temperature is then increased stepwise. The paper is devoted to the mathematical modelling and simulation of experimental studies. In the corresponding boundary-value problem with nonlinear dynamic boundary conditions physical- chemical processes in the bulk and on the surface are taken into account: heating of the sample, diffusion in the bulk, hydrogen capture by defects, penetration from the bulk to the surface and desorption. The model aimed to analyze the dynamics of hydrogen concentrations without preliminary artificial sample saturation. Numerical modelling allows to choose the point on the extraction curve that corresponds to the initial quantity of the surface hydrogen, to estimate the values of the activation energies of diffusion, desorption, parameters of reversible capture and hydride phase decomposition. (paper)

  17. Gas desorption during friction of amorphous carbon films

    International Nuclear Information System (INIS)

    Rusanov, A; Fontaine, J; Martin, J-M; Mogne, T L; Nevshupa, R

    2008-01-01

    Gas desorption induced by friction of solids, i.e. tribodesorption, is one of the numerous physical and chemical phenomena, which arise during friction as result of thermal and structural activation of material in a friction zone. Tribodesorption of carbon oxides, hydrocarbons, and water vapours may lead to significant deterioration of ultra high vacuum conditions in modern technological equipment in electronic, optoelectronic industries. Therefore, knowledge of tribodesorption is crucial for the performance and lifetime of vacuum tribosystems. Diamond-like carbon (DLC) coatings are interesting materials for vacuum tribological systems due to their high wear resistance and low friction. Highly hydrogenated amorphous carbon (a-C:H) films are known to exhibit extremely low friction coefficient under high vacuum or inert environment, known as 'superlubricity' or 'superlow friction'. However, the superlow friction period is not always stable and then tends to spontaneous transition to high friction. It is supposed that hydrogen supply from the bulk to the surface is crucial for establishing and maintaining superlow friction. Thus, tribodesorption can serve also as a new technique to determine the role of gases in superlow friction mechanisms. Desorption of various a-C:H films, deposited by PECVD, ion-beam deposition and deposition using diode system, has been studied by means of ultra-high vacuum tribometer equipped with a mass spectrometer. It was found that in superlow friction period desorption rate was below the detection limit in the 0-85 mass range. However, transition from superlow friction to high friction was accompanied by desorption of various gases, mainly of H 2 and CH 4 . During friction transition, surfaces were heavily damaged. In experiments with DLC films with low hydrogen content tribodesorption was significant during the whole experiment, while low friction was not observed. From estimation of maximum surface temperature during sliding contact it

  18. Deuterium desorption from tungsten using laser heating

    Directory of Open Access Journals (Sweden)

    J.H. Yu

    2017-08-01

    Full Text Available Retention and desorption of hydrogenic species need to be accurately modeled to predict the tritium inventory of next generation fusion devices, which is needed both for tritium fuel recovery and for tritium safety concerns. In this paper, experiments on thermal desorption of deuterium from intrinsic polycrystalline tungsten defects using laser heating are compared to TMAP-7 modeling. The samples during deuterium plasma exposure were at a temperature of 373K for this benchmark study with ion fluence of 0.7–1.0 ×1024Dm−2. Following plasma exposure, a fiber laser (λ= 1100nm heated the samples to peak surface temperatures ranging from ∼500 to 1400K with pulse widths from 10ms to 1s, and 1 to 10 pulses applied to each sample. The remaining deuterium retention was measured using temperature programmed desorption (TPD. Results show that > 95% of deuterium is desorbed when the peak surface temperature reached ∼950K for > 1s. TMAP-7 is used to predict deuterium desorption from tungsten for a range of surface temperatures and heating durations, and is compared to previous work on desorption from beryllium codeposits.

  19. A recombinant Anticarsia gemmatalis MNPV harboring chiA and v-cath genes from Choristoneura fumiferana defective NPV induce host liquefaction and increased insecticidal activity.

    Directory of Open Access Journals (Sweden)

    Anabele Azevedo Lima

    Full Text Available One of the interesting features of Anticarsia gemmatalis multiple nucleopolyhedrovirus isolate 2D (AgMNPV-2D genome is the absence of chitinase (chiA and cathepsin (v-cath genes. This characteristic may be responsible for the lack of liquefaction and melanization in A. gemmatalis larvae killed by AgMNPV-2D infection. This study aimed to test the hypothesis that CHIA and V-CATH proteins from Choristonera fumiferana DEF multiple nucleopolyhedrovirus (CfDEFNPV are able to liquefy and melanize the cuticle of A. gemmatalis larvae infected by a recombinant AgMNPV containing chiA and v-cath genes inserted in its genome. A fragment from the CfDefNPV genome containing chiA and v-cath genes was inserted into the genome of AgMNPV-2D. The recombinant virus (vAgp2100Cf.chiA/v-cath was purified and used to infect insect cells and larvae. Transcripts of v-cath and chiA genes were detected along the infection of insect cells by qRT-PCR, from early to late phases of infection. The analysis of A. gemmatalis larvae killed by vAgp2100Cf.chiA/v-cath infection confirmed the hypothesis proposed. The vAgp2100Cf.chiA/v-cath showed higher insecticidal activity against third instar A. gemmatalis larvae when compared to AgMNPV-2D. The mean time to death was also lower for the vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D at 10 days post infection. Occlusion body production was higher in A. gemmatalis larvae infected with vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D. Enzyme assays showed higher chitinase and cysteine protease activities in insect cells and insects infected with vAgp2100Cf.chiA/v-cath when compared to AgMNPV-2D. The introduction of chiA and v-cath genes into the genome of AgMNPV improves its insecticidal activity against A. gemmatalis larvae and this recombinant virus could be used as an alternative to the wild type virus to control this important insect pest.

  20. Krypton-85 enrichment by adsorption-desorption process

    International Nuclear Information System (INIS)

    Khan, A.A.; Deshingkar, D.S.; Ramarathinam, K.

    1975-01-01

    The use of activated charcoal columns in conjunction with cryogenic distillation system for concentration of krypton-85 in fuel reprocessing process off-gas stream is reported. Dynamic adsorption of krypton on activated charcoals and its subsequent desorption by applying vacuum were studied. The possible reduction in the quantity of carrier gas to be liquified in the cryogenic system by utilising this process has been discussed on the basis of results of laboratory evaluations. The possibility of elimination of air and oxygen to avoid explosion hazards associated with radiolytic formation and concentration of ozone has also been considered. (author)

  1. Measurement of basophil-activating capacity of grass pollen allergens, allergoids and hypoallergenic recombinant derivatives by flow cytometry using anti-CD203c.

    Science.gov (United States)

    Kahlert, H; Cromwell, O; Fiebig, H

    2003-09-01

    The assessment of the basophil-activating potential is an important aspect in the development of improved preparations for specific immunotherapy. The aim of the study was to evaluate the suitability of CD203c expression as a measure of basophil activation to compare allergoids with original allergen extracts, and recombinant hypoallergenic allergen derivatives with recombinant wild-type and natural allergens. Heparinized whole blood samples from grass pollen allergic subjects were stimulated with grass pollen allergens and allergen derivatives followed by labelling of the basophils with PE-conjugated anti-CD203c. After lysis of the erythrocytes and fixation, the basophils were detected by flow cytometry. In some experiments, histamine release was determined simultaneously. Grass pollen allergoids revealed a 10-10 000-fold reduction of basophil-activating capacity measured by CD203c expression. The deletion mutant DM4 of rPhl p 5b showed stronger hypoallergenic characteristics in a range of 50-10 000-fold reduction, whereas a combination mutant of rPhl p 5b and Phl p 6 revealed less hypoallergenic features. Histamine release experiments led to a similar outcome as CD203c measurement. The measurement of CD203c expression on basophils by flow cytometry provides a rapid and sensitive method for the estimation of the allergic or hypoallergenic features of allergen preparations. The results demonstrated the hypoallergenicity of grass pollen allergoids and of the rPhl p 5b variant DM4, which may be a candidate in future preparations for specific immunotherapy.

  2. Ionic Adsorption and Desorption of CNT Nanoropes

    Directory of Open Access Journals (Sweden)

    Jun-Jun Shang

    2016-09-01

    Full Text Available A nanorope is comprised of several carbon nanotubes (CNTs with different chiralities. A molecular dynamic model is built to investigate the ionic adsorption and desorption of the CNT nanoropes. The charge distribution on the nanorope is obtained by using a modified gradient method based on classical electrostatic theory. The electrostatic interactions among charged carbon atoms are calculated by using the Coulomb law. It was found here that the charged nanorope can adsorb heavy metal ions, and the adsorption and desorption can be realized by controlling the strength of applied electric field. The distance between the ions and the nanorope as well as the amount of ions have an effect on the adsorption capacity of the nanorope. The desorption process takes less time than that of adsorption. The study indicates that the CNT nanorope can be used as a core element of devices for sewage treatment.

  3. Potent antitumor activities of recombinant human PDCD5 protein in combination with chemotherapy drugs in K562 cells

    International Nuclear Information System (INIS)

    Shi, Lin; Song, Quansheng; Zhang, Yingmei; Lou, Yaxin; Wang, Yanfang; Tian, Linjie; Zheng, Yi; Ma, Dalong; Ke, Xiaoyan; Wang, Ying

    2010-01-01

    Conventional chemotherapy is still frequently used. Programmed cell death 5 (PDCD5) enhances apoptosis of various tumor cells triggered by certain stimuli and is lowly expressed in leukemic cells from chronic myelogenous leukemia patients. Here, we describe for the first time that recombinant human PDCD5 protein (rhPDCD5) in combination with chemotherapy drugs has potent antitumor effects on chronic myelogenous leukemia K562 cells in vitro and in vivo. The antitumor efficacy of rhPDCD5 protein with chemotherapy drugs, idarubicin (IDR) or cytarabine (Ara-C), was examined in K562 cells in vitro and K562 xenograft tumor models in vivo. rhPDCD5 protein markedly increased the apoptosis rates and decreased the colony-forming capability of K562 cells after the combined treatment with IDR or Ara-C. rhPDCD5 protein by intraperitoneal administration dramatically improved the antitumor effects of IDR treatment in the K562 xenograft model. The tumor sizes and cell proliferation were significantly decreased; and TUNEL positive cells were significantly increased in the combined group with rhPDCD5 protein and IDR treatment compared with single IDR treatment groups. rhPDCD5 protein, in combination with IDR, has potent antitumor effects on chronic myelogenous leukemia K562 cells and may be a novel and promising agent for the treatment of chronic myelogenous leukemia.

  4. STM-Induced Hydrogen Desorption via a Hole Resonance

    DEFF Research Database (Denmark)

    Stokbro, Kurt; Thirstrup, C.; Sakurai, M.

    1998-01-01

    We report STM-induced desorption of H from Si(100)-H(2 X 1) at negative sample bias. The desorption rate exhibits a power-law dependence on current and a maximum desorption rate at -7 V. The desorption is explained by vibrational heating of H due to inelastic scattering of tunneling holes...... with the Si-H 5 sigma hole resonance. The dependence of desorption rate on current and bias is analyzed using a novel approach for calculating inelastic scattering, which includes the effect of the electric field between tip and sample. We show that the maximum desorption rate at -7 V is due to a maximum...

  5. High-yield production of biologically active recombinant protein in shake flask culture by combination of enzyme-based glucose delivery and increased oxygen transfer

    Directory of Open Access Journals (Sweden)

    Ukkonen Kaisa

    2011-12-01

    Full Text Available Abstract This report describes the combined use of an enzyme-based glucose release system (EnBase® and high-aeration shake flask (Ultra Yield Flask™. The benefit of this combination is demonstrated by over 100-fold improvement in the active yield of recombinant alcohol dehydrogenase expressed in E. coli. Compared to Terrific Broth and ZYM-5052 autoinduction medium, the EnBase system improved yield mainly through increased productivity per cell. Four-fold increase in oxygen transfer by the Ultra Yield Flask contributed to higher cell density with EnBase but not with the other tested media, and consequently the product yield per ml of EnBase culture was further improved.

  6. The role of recombinant activated factor VII in the haematological management of elective orthopaedic surgery in haemophilia A patients with inhibitors

    Science.gov (United States)

    Castaman, Giancarlo

    2017-01-01

    The clinical profile and expectations of haemophilic patients with inhibitors have changed over the last three decades, mainly because of the prolongation of life-expectancy, often resulting in an increase of the orthopaedic burden. Recombinant activated factor VII (rFVIIa) is the most frequently used bypassing agent in haemophilia patients with inhibitors during elective orthopaedic surgery. For nearly 30 years, rFVIIa has been successfully used to control haemostasis in several major and minor surgical procedures. Clinical trials, case series, reports and surveys were progressively aimed at optimising rFVIIa usage in very demanding conditions managed in highly specialised centres. Recommendations from consensus opinions and guidelines have been provided on the basis of this clinical experience. PMID:28686157

  7. Verification of key odorants in rose oil by gas chromatography-olfactometry/aroma extract dilution analysis, odour activity value and aroma recombination.

    Science.gov (United States)

    Xiao, Zuobing; Li, Jing; Niu, Yunwei; Liu, Qiang; Liu, Junhua

    2017-10-01

    Rose oil is much too expensive but very popular. It's well known that the flower oil's aroma profile hasn't been intensively investigated. In order to verify the aroma profile of rose oil, the synthetic blend of odorants was prepared and then compared with the original rose oil using electronic nose analysis (ENA) combined with quantitative descriptive analysis (QDA). The odorants from rose oils were screened out by Gas Chromatography-Olfactometry/aroma extract dilution analysis (GC-O/AEDA) combined with odour activity value (OAV). Both ENA and QDA indicated the recombination model derived from OAV and GC-O/AEDA closely resembled the original rose oil. The experiment results show that rose oxide, linalool, α-pinene, β-pinene, nonanal, heptanal citronellal, phenyl ethyl alcohol, benzyl alcohol, eugenol, methyl eugenol, β-citronellol, hexyl acetate, β-ionone, nerol, etc. are very important constituent to rose oil aroma profile.

  8. Effect of recombinant tissue-type plasminogen activator on acute myocardial infarction; Limitation of infarct size and preservation of left ventricular function evaluated by radionuclide methods

    Energy Technology Data Exchange (ETDEWEB)

    Fukuyama, Takaya; Inou, Tetsuji; Ashihara, Toshiaki; Ogata, Ikuo; Nabeyama, Shouzou; Yamada, Akira; Murakami, Satoshi; Kodama, Mayuko; Matsui, Kanji (Matsuyama Red Cross Hospital, Ehime (Japan))

    1989-12-01

    Radionuclide studies were performed in 18 patients with acute myocardial infarction receiving i.v. injection of recombinant tissue-type plasminogen activator (rt-PA) within 12 hr after an attack. Thallium-201 single photon emission computed tomography revealed that infarct size decreased by 42% in the rt-PA treated group, as compared with 25% in the control group. Left ventricular ejection fraction, as found on first-pass radionuclide angiography with Tc-99m PYP, was significantly higher in the rt-PA treated group than the control group (49% vs 38%). Radionuclide imagings were helpful in confirming myocardial salvage after rt-PA intravenous therapy. It was also considered necessary to perform rt-PA therapy as early as possible after an acute myocardial attack. (N.K.).

  9. Taguchi Experimental Design for Optimization of Recombinant Human Growth Hormone Production in CHO Cell Lines and Comparing its Biological Activity with Prokaryotic Growth Hormone.

    Science.gov (United States)

    Aghili, Zahra Sadat; Zarkesh-Esfahani, Sayyed Hamid

    2018-02-01

    Growth hormone deficiency results in growth retardation in children and the GH deficiency syndrome in adults and they need to receive recombinant-GH in order to rectify the GH deficiency symptoms. Mammalian cells have become the favorite system for production of recombinant proteins for clinical application compared to prokaryotic systems because of their capability for appropriate protein folding, assembly, post-translational modification and proper signal. However, production level in mammalian cells is generally low compared to prokaryotic hosts. Taguchi has established orthogonal arrays to describe a large number of experimental situations mainly to reduce experimental errors and to enhance the efficiency and reproducibility of laboratory experiments.In the present study, rhGH was produced in CHO cells and production of rhGH was assessed using Dot blotting, western blotting and Elisa assay. For optimization of rhGH production in CHO cells using Taguchi method An M16 orthogonal experimental design was used to investigate four different culture components. The biological activity of rhGH was assessed using LHRE-TK-Luciferase reporter gene system in HEK-293 and compared to the biological activity of prokaryotic rhGH.A maximal productivity of rhGH was reached in the conditions of 1%DMSO, 1%glycerol, 25 µM ZnSO 4 and 0 mM NaBu. Our findings indicate that control of culture conditions such as the addition of chemical components helps to develop an efficient large-scale and industrial process for the production of rhGH in CHO cells. Results of bioassay indicated that rhGH produced by CHO cells is able to induce GH-mediated intracellular cell signaling and showed higher bioactivity when compared to prokaryotic GH at the same concentrations. © Georg Thieme Verlag KG Stuttgart · New York.

  10. Implication of extracellular zinc exclusion by recombinant human calprotectin (MRP8 and MRP14) from target cells in its apoptosis-inducing activity.

    Science.gov (United States)

    Yui, Satoru; Nakatani, Yuichi; Hunter, Michael J; Chazin, Walter J; Yamazaki, Masatoshi

    2002-06-01

    Calprotectin is a calcium-binding and zinc-binding protein complex that is abundant in the cytosol of neutrophils. This factor is composed of 8 and 14 kDa subunits, which have also been termed migration inhibitory factor-related proteins MRP8 and MRP14. We previously reported that rat calprotectin purified from inflammatory neutrophils induces apoptosis of various tumor cells or normal fibroblasts in a zinc-reversible manner. The present study was undertaken to elucidate which subunit is responsible for the apoptosis-inducing activity, and to explore the mechanism of zinc-reversible apoptosis induction. The apoptosis-inducing activity of recombinant human MRP8 (rhMRP8) and recombinant human MRP14 (rhMRP14) was examined against EL-4 lymphoma cells in vitro. To determine whether zinc deprivation by calprotectin was essential for the cytotoxicity, the activity of calprotectin was tested under conditions where physical contact between the factor and the cells was precluded by a low molecular weight cut-off dialysis membrane. The cytotoxicity of rhMRP14 against EL-4 cells was first detected at 10 microM in a standard medium, whereas rhMRP8 caused only marginal cytotoxicity at 40 microM. A mixture of both proteins showed higher specific activity (onset of cytotoxicity at 5 microM). When the cells were cultured in divalent cation-depleted medium, each dose-response curve was shifted to about a four-fold lower concentration range. Calprotectin was found to induce cell death even when the complex and the target cells were separated by dialysis membrane. A membrane-impermeable zinc chelator, diethylenetriamine pentaacetic acid (DTPA), also induced target cell apoptosis in a similar time-course as calprotectin. Moreover, the activities of calprotectin and DTPA were completely inhibited by the presence of zinc ions. These data indicate that calprotectin has higher specific activity to induce apoptosis than the Individual subunits, and that the mechanism is exclusion of zinc

  11. Therapeutic Recombinant Monoclonal Antibodies

    Science.gov (United States)

    Bakhtiar, Ray

    2012-01-01

    During the last two decades, the rapid growth of biotechnology-derived techniques has led to a myriad of therapeutic recombinant monoclonal antibodies with significant clinical benefits. Recombinant monoclonal antibodies can be obtained from a number of natural sources such as animal cell cultures using recombinant DNA engineering. In contrast to…

  12. Identification, recombinant production and partial biochemical characterization of an extracellular cold-active serine-metalloprotease from an Antarctic Pseudomonas isolate

    Directory of Open Access Journals (Sweden)

    Natalia Fullana

    2017-08-01

    Full Text Available Cold-adapted enzymes are generally derived from psychrophilic microorganisms and have features that make them very attractive for industrial and biotechnological purposes. In this work, we identified a 50 kDa extracellular protease (MP10 from the Antarctic isolate Pseudomonas sp. AU10. The enzyme was produced by recombinant DNA technology, purified using immobilized metal affinity chromatography and partially characterized. MP10 is an alkaline thermosensitive serine-metallo protease with optimal activity at pH 8.0 and 40 ℃, in the presence of 1.5 mM Ca2+. MP10 showed 100% residual activity and stability (up to 60 min when incubated with 7% of non-ionic surfactants (Triton X-100, Tween-80 and Tween-20 and 1.5% of the oxidizing agent hydrogen peroxide. The 3D MP10 structure was predicted and compared with the crystal structure of mesophilic homologous protease produced by Pseudomonas aeruginosa PA01 (reference strain and other proteases, showing similarity in surface area and volume of proteins, but a significantly higher surface pocket area and volume of MP10. The observed differences presumably may explain the enhanced activity of MP10 for substrate binding at low temperatures. These results give insight to the potential use of MP10 in developing new biotechnologically processes active at low to moderate temperatures, probably with focus in the detergent industry.

  13. Improving recombinant protein purification yield

    Science.gov (United States)

    Production of adequate amounts of recombinant proteins is essential for antibody production, biochemical activity study, and structural determination during the post-genomic era. It’s technologically challenging and a limiting factor for tung oil research because analytical reagents such as high qua...

  14. Secondary ion shadow-cone enhanced desorption

    Energy Technology Data Exchange (ETDEWEB)

    Chechen Chang (Hawaii Univ., Honolulu (USA). Dept. of Chemistry)

    1990-02-01

    The incident angle dependence of the secondary particle emission process under keV ion bombardment has been investigated. The results from the full molecular dynamics calculations indicate that the flux anisotropy of the incident beam, resulting from the non-uniform impact parameters for the surface atom of a single crystal, affects the particle desorption in a systematic fashion. The enhanced desorption at certain angles of incidence corresponds to the intensive focusing of the incident beam to the near-surface atom and the extended dissipation of momentum by large-angle scattering. This observation has let us to develop a new theoretical model in which the enhanced desorption is described by the distance of closest encounter along the trajectory of the incident particle to the surface atom. The computer time for the simulation of the incident-angle-dependent emission process is significantly reduced. The results from the calculation based on this model are in good agreement both with the results from the full dynamics calculation and with the experimental results. The new model also allows a complementary evaluation of the microscopic dynamics involved in the shadow-cone enhanced desorption. (author).

  15. Exciton-Promoted Desorption From Solid Water Surfaces A2

    DEFF Research Database (Denmark)

    McCoustra, M.R.S.; Thrower, J.D.

    2018-01-01

    Abstract Desorption from solid water surfaces resulting from interaction with electromagnetic and particle radiation is reviewed in the context of the role of nonthermal desorption in astrophysical environments. Experimental observations are interpreted in terms of mechanisms sharing a common basis...

  16. Magnesium growth in magnesium deuteride thin films during deuterium desorption

    Energy Technology Data Exchange (ETDEWEB)

    Checchetto, R., E-mail: riccardo.checchetto@unitn.it [Dipartimento di Fisica and CNISM, Università di Trento, Via Sommarive 14, I-38123 Trento (Italy); Miotello, A. [Dipartimento di Fisica and CNISM, Università di Trento, Via Sommarive 14, I-38123 Trento (Italy); Mengucci, P.; Barucca, G. [Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio, Università Politecnica delle Marche, I-60131 Ancona (Italy)

    2013-12-15

    Highlights: ► Highly oriented Pd-capped magnesium deuteride thin films. ► The MgD{sub 2} dissociation was studied at temperatures not exceeding 100 °C. ► The structure of the film samples was analyzed by XRD and TEM. ► The transformation is controlled by the re-growth velocity of the Mg layers. ► The transformation is thermally activated, activation energy value of 1.3 ± 0.1 eV. -- Abstract: Pd- capped nanocrystalline magnesium thin films having columnar structure were deposited on Si substrate by e-gun deposition and submitted to thermal annealing in D{sub 2} atmosphere to promote the metal to deuteride phase transformation. The kinetics of the reverse deuteride to metal transformation was studied by Thermal Desorption Spectroscopy (TDS) while the structure of the as deposited and transformed samples was analyzed by X-rays diffraction and Transmission Electron Microscopy (TEM). In Pd- capped MgD{sub 2} thin films the deuteride to metal transformation begins at the interface between un-reacted Mg and transformed MgD{sub 2} layers. The D{sub 2} desorption kinetics is controlled by MgD{sub 2}/Mg interface effects, specifically the re-growth velocity of the Mg layers. The Mg re-growth has thermally activated character and shows an activation energy value of 1.3 ± 0.1 eV.

  17. Requirement of 8-mercaptoguanosine as a costimulus for IL-4-dependent μ to γ1 class switch recombination in CD38-activated B cells

    International Nuclear Information System (INIS)

    Tsukamoto, Yumiko; Uehara, Shoji; Mizoguchi, Chieko; Sato, Atsushi; Horikawa, Keisuke; Takatsu, Kiyoshi

    2005-01-01

    Mature B-2 cells expressing surface IgM and IgD proliferate upon stimulation by CD38, CD40 or lipopolysaccharide (LPS) and differentiate into IgG1-producing plasma cells in the presence of cytokines. The process of class switch recombination (CSR) from IgM to other isotypes is highly regulated by cytokines and activation-induced cytidine deaminase (AID). Blimp-1 and XBP-1 play an essential role in the terminal differentiation of switched B-2 cells to Ig-producing plasma cells. IL-5 induces AID and Blimp-1 expression in CD38- and CD40-activated B-2 cells, leading to μ to γ1 CSR at DNA level and IgG1 production. IL-4, a well-known IgG1-inducing factor, does not induce μ to γ1 CSR in CD38-activated B-2 cells or Blimp-1, while IL-4 induces μ to γ1 CSR, XBP-1 expression, and IgG1 production expression in CD40-activated B-2 cells. Interestingly, the addition of 8-mercaptoguanosine (8-SGuo) with IL-4 to the culture of CD38-activated B cells can induce μ to γ1 CSR, Blimp-1 expression, and IgG1 production. Intriguingly, 8-SGuo by itself induces AID expression in CD38-activated B cells. However, it does not induce μ to γ1 CSR. These results imply that the mode of B-cell activation for extracellular stimulation affects the outcome of cytokine stimulation with respect to the efficiency and direction of CSR, and the requirements of the transcriptional regulator and the generation of antibody-secreting cells. Furthermore, our data suggest the requirement of additional molecules in addition to AID for CSR

  18. Data compilation for particle-impact desorption, 2

    International Nuclear Information System (INIS)

    Oshiyama, Takashi; Nagai, Siro; Ozawa, Kunio; Takeutchi, Fujio.

    1985-07-01

    The particle impact desorption is one of the elementary processes of hydrogen recycling in controlled thermonuclear fusion reactors. We have surveyed the literature concerning the ion impact desorption and photon stimulated desorption published through the end of 1984 and compiled the data on the desorption cross sections and yields with the aid of a computer. This report presents the results of the compilation in graphs and tables as functions of incident energy, surface temperature and surface coverage. (author)

  19. Activity of the Human Rhinovirus 3C Protease Studied in Various Buffers, Additives and Detergents Solutions for Recombinant Protein Production

    DEFF Research Database (Denmark)

    Ullah, Raheem; Shah, Majid Ali; Tufail, Soban

    2016-01-01

    stringent sequence specificity and enhanced activity. Like other proteases, activity of the human rhinovirus 3C protease can be affected in part by the buffer components and additives that are generally employed for purification and stabilization of proteins, hence, necessitate their removal by tedious...

  20. Photoionization and Recombination

    Science.gov (United States)

    Nahar, Sultana N.

    2000-01-01

    Theoretically self-consistent calculations for photoionization and (e + ion) recombination are described. The same eigenfunction expansion for the ion is employed in coupled channel calculations for both processes, thus ensuring consistency between cross sections and rates. The theoretical treatment of (e + ion) recombination subsumes both the non-resonant recombination ("radiative recombination"), and the resonant recombination ("di-electronic recombination") processes in a unified scheme. In addition to the total, unified recombination rates, level-specific recombination rates and photoionization cross sections are obtained for a large number of atomic levels. Both relativistic Breit-Pauli, and non-relativistic LS coupling, calculations are carried out in the close coupling approximation using the R-matrix method. Although the calculations are computationally intensive, they yield nearly all photoionization and recombination parameters needed for astrophysical photoionization models with higher precision than hitherto possible, estimated at about 10-20% from comparison with experimentally available data (including experimentally derived DR rates). Results are electronically available for over 40 atoms and ions. Photoionization and recombination of He-, and Li-like C and Fe are described for X-ray modeling. The unified method yields total and complete (e+ion) recombination rate coefficients, that can not otherwise be obtained theoretically or experimentally.

  1. Recombinant tumor necrosis factor alpha inhibits growth of methylcholanthrene-induced sarcoma and enhances natural killer activity of tumor-infiltrating lymphocytes in aging rats

    International Nuclear Information System (INIS)

    Ziolkowska, Maria; Nowak Joanna, J.; Janiak, Marek; Ryzewska, Alicja

    1994-01-01

    The effect of recombinant human tumor necrosis factors alpha (rHuTNF-α) on the growth of immunogenic, methylcholanthrene-induced sarcoma (MC-Sa) and natural killer (NK) cell activity of tumor-infiltrating lymphocytes (TIL) in adult and aging rats was investigated. In both groups of animals the growth of transplantable MC-Sa was markedly and similarly inhibited by multiple intratumoral (i.t.) injections of rHuTF-α. This effect was accompanied by stimulation of NK activity of tumor-infiltrating lymphocytes in adult as well as in aging rats. Studies ''in vitro'' demonstrated additionally that rHuTNF-α was a potent stimulator of NK but not of ADCC (antibody-dependent cellular cytotoxicity) activity of spleen lymphocytes from healthy animals. Our results indicate that the antitumor effect of TNF-α is comparable in adult and in aging rats bearing immunogenic MC-Sa. The inhibition of MC-Sa growth may be attributed not only to the TNF-α-induced necrosis of the neoplastic tissue but also to the ''in vivo'' stimulatory effect of this cytokine upon the NK-type function of lymphocytes infiltrating the tumor mass. (author). 31 refs, 5 figs, 2 tabs

  2. Desorption of intrinsic cesium from smectite: inhibitive effects of clay particle organization on cesium desorption.

    Science.gov (United States)

    Fukushi, Keisuke; Sakai, Haruka; Itono, Taeko; Tamura, Akihiro; Arai, Shoji

    2014-09-16

    Fine clay particles have functioned as transport media for radiocesium in terrestrial environments after nuclear accidents. Because radiocesium is expected to be retained in clay minerals by a cation-exchange reaction, ascertaining trace cesium desorption behavior in response to changing solution conditions is crucially important. This study systematically investigated the desorption behavior of intrinsic Cs (13 nmol/g) in well-characterized Na-montmorillonite in electrolyte solutions (NaCl, KCl, CaCl2, and MgCl2) under widely differing cation concentrations (0.2 mM to 0.2 M). Batch desorption experiments demonstrated that Cs(+) desorption was inhibited significantly in the presence of the environmental relevant concentrations of Ca(2+) and Mg(2+) (>0.5 mM) and high concentrations of K(+). The order of ability for Cs desorption was Na(+) = K(+) > Ca(2+) = Mg(2+) at the highest cation concentration (0.2 M), which is opposite to the theoretical prediction based on the cation-exchange selectivity. Laser diffraction grain-size analyses revealed that the inhibition of Cs(+) desorption coincided with the increase of the clay tactoid size. Results suggest that radiocesium in the dispersed fine clay particles adheres on the solid phase when the organization of swelling clay particles occurs because of changes in solution conditions caused by both natural processes and artificial treatments.

  3. Stereospecific suppression of active site mutants by methylphosphonate substituted substrates reveals the stereochemical course of site-specific DNA recombination

    OpenAIRE

    Rowley, Paul A.; Kachroo, Aashiq H.; Ma, Chien-Hui; Maciaszek, Anna D.; Guga, Piotr; Jayaram, Makkuni

    2015-01-01

    Tyrosine site-specific recombinases, which promote one class of biologically important phosphoryl transfer reactions in DNA, exemplify active site mechanisms for stabilizing the phosphate transition state. A highly conserved arginine duo (Arg-I; Arg-II) of the recombinase active site plays a crucial role in this function. Cre and Flp recombinase mutants lacking either arginine can be rescued by compensatory charge neutralization of the scissile phosphate via methylphosphonate (MeP) modificati...

  4. The level of glucose-6-phosphate dehydrogenase activity strongly influences xylose fermentation and inhibitor sensitivity in recombinant Saccharomyces cerevisiae strains

    DEFF Research Database (Denmark)

    Jeppsson, M.; Johansson, B.; Jensen, Peter Ruhdal

    2003-01-01

    production levels of G6PDH on xylose fermentation. We used a synthetic promoter library and the copper-regulated CUP1 promoter to generate G6PDH-activities between 0% and 179% of the wildtype level. G6PDH-activities of 1% and 6% of the wild-type level resulted in 2.8- and 5.1-fold increase in specific xylose...

  5. Production of enzymatically active recombinant full-length barley high pI alpha-glucosidase of glycoside family 31 by high cell-density fermentation of Pichia pastoris and affinity purification

    DEFF Research Database (Denmark)

    Næsted, Henrik; Kramhøft, Birte; Lok, F.

    2006-01-01

    Recombinant barley high pI alpha-glucosidase was produced by high cell-density fermentation of Pichia pastoris expressing the cloned full-length gene. The gene was amplified from a genomic clone and exons (coding regions) were assembled by overlap PCR. The resulting cDNA was expressed under contr...... nM x s(-1), and 85 s(-1) using maltose as substrate. This work presents the first production of fully active recombinant alpha-glucosidase of glycoside hydrolase family 31 from higher plants. (c) 2005 Elsevier Inc. All rights reserved....

  6. Exceptionally high levels of recombination across the honey bee genome.

    Science.gov (United States)

    Beye, Martin; Gattermeier, Irene; Hasselmann, Martin; Gempe, Tanja; Schioett, Morten; Baines, John F; Schlipalius, David; Mougel, Florence; Emore, Christine; Rueppell, Olav; Sirviö, Anu; Guzmán-Novoa, Ernesto; Hunt, Greg; Solignac, Michel; Page, Robert E

    2006-11-01

    The first draft of the honey bee genome sequence and improved genetic maps are utilized to analyze a genome displaying 10 times higher levels of recombination (19 cM/Mb) than previously analyzed genomes of higher eukaryotes. The exceptionally high recombination rate is distributed genome-wide, but varies by two orders of magnitude. Analysis of chromosome, sequence, and gene parameters with respect to recombination showed that local recombination rate is associated with distance to the telomere, GC content, and the number of simple repeats as described for low-recombining genomes. Recombination rate does not decrease with chromosome size. On average 5.7 recombination events per chromosome pair per meiosis are found in the honey bee genome. This contrasts with a wide range of taxa that have a uniform recombination frequency of about 1.6 per chromosome pair. The excess of recombination activity does not support a mechanistic role of recombination in stabilizing pairs of homologous chromosome during chromosome pairing. Recombination rate is associated with gene size, suggesting that introns are larger in regions of low recombination and may improve the efficacy of selection in these regions. Very few transposons and no retrotransposons are present in the high-recombining genome. We propose evolutionary explanations for the exceptionally high genome-wide recombination rate.

  7. Kinetic characterization of recombinant Bacillus coagulans FDP-activated l-lactate dehydrogenase expressed in Escherichia coli and its substrate specificity.

    Science.gov (United States)

    Jiang, Ting; Xu, Yanbing; Sun, Xiucheng; Zheng, Zhaojuan; Ouyang, Jia

    2014-03-01

    Bacillus coagulans is a homofermentative, acid-tolerant and thermophilic sporogenic lactic acid bacterium, which is capable of producing high yields of optically pure lactic acid. The l-(+)-lactate dehydrogenase (l-LDH) from B. coagulans is considered as an ideal biocatalyst for industrial production. In this study, the gene ldhL encoding a thermostable l-LDH was amplified from B. coagulans NL01 genomic DNA and successfully expressed in Escherichia coli BL21 (DE3). The recombinant enzyme was partially purified and its enzymatic properties were characterized. Sequence analysis demonstrated that the l-LDH was a fructose 1,6-diphosphate-activated NAD-dependent lactate dehydrogenase (l-nLDH). Its molecular weight was approximately 34-36kDa. The Km and Vmax values of the purified l-nLDH for pyruvate were 1.91±0.28mM and 2613.57±6.43μmol(minmg)(-1), respectively. The biochemical properties of l-nLDH showed that the specific activity were up to 2323.29U/mg with optimum temperature of 55°C and pH of 6.5 in the pyruvate reduction and 351.01U/mg with temperature of 55°C and pH of 11.5 in the lactate oxidation. The enzyme also showed some activity in the absence of FDP, with a pH optimum of 4.0. Compared to other lactic acid bacterial l-nLDHs, the enzyme was found to be relatively stable at 50°C. Ca(2+), Ba(2+), Mg(2+) and Mn(2+) ions had activated effects on the enzyme activity, and the enzyme was greatly inhibited by Ni(2+) ion. Besides these, l-nLDH showed the higher specificity towards pyruvate esters, such as methyl pyruvate and ethyl pyruvate. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Dual inhibition of ATR and ATM potentiates the activity of trabectedin and lurbinectedin by perturbing the DNA damage response and homologous recombination repair.

    Science.gov (United States)

    Lima, Michelle; Bouzid, Hana; Soares, Daniele G; Selle, Frédéric; Morel, Claire; Galmarini, Carlos M; Henriques, João A P; Larsen, Annette K; Escargueil, Alexandre E

    2016-05-03

    Trabectedin (Yondelis®, ecteinascidin-743, ET-743) is a marine-derived natural product approved for treatment of advanced soft tissue sarcoma and relapsed platinum-sensitive ovarian cancer. Lurbinectedin is a novel anticancer agent structurally related to trabectedin. Both ecteinascidins generate DNA double-strand breaks that are processed through homologous recombination repair (HRR), thereby rendering HRR-deficient cells particularly sensitive. We here characterize the DNA damage response (DDR) to trabectedin and lurbinectedin in HeLa cells. Our results show that both compounds activate the ATM/Chk2 (ataxia-telangiectasia mutated/checkpoint kinase 2) and ATR/Chk1 (ATM and RAD3-related/checkpoint kinase 1) pathways. Interestingly, pharmacological inhibition of Chk1/2, ATR or ATM is not accompanied by any significant improvement of the cytotoxic activity of the ecteinascidins while dual inhibition of ATM and ATR strongly potentiates it. Accordingly, concomitant inhibition of both ATR and ATM is an absolute requirement to efficiently block the formation of γ-H2AX, MDC1, BRCA1 and Rad51 foci following exposure to the ecteinascidins. These results are not restricted to HeLa cells, but are shared by cisplatin-sensitive and -resistant ovarian carcinoma cells. Together, our data identify ATR and ATM as central coordinators of the DDR to ecteinascidins and provide a mechanistic rationale for combining these compounds with ATR and ATM inhibitors.

  9. Isolation of a Spodoptera exigua baculovirus recombinant with retained biological activity despite a 10.6 kb deletion

    NARCIS (Netherlands)

    Dai, X.; Hajos, J.P.; Joosten, N.N.; Oers, van M.M.; IJkel, W.F.J.; Zuidema, D.; Yi, P.

    2000-01-01

    When Spodoptera exigua multicapsid nucleopolyhedrovirus (SeMNPV) is grown in insect cell culture, defective viruses are generated. These viruses lack about 25 kbp of sequence information and are no longer infectious for insects. This makes the engineering of SeMNPV for improved insecticidal activity

  10. An explanation of efficiency droop in InGaN-based light emitting diodes: saturated radiative recombination rate at randomly distributed In-rich active areas

    International Nuclear Information System (INIS)

    Shim, Jong-In; Kim, Hyun-Sung; Shin, Dong-Soo; Yoo, Han-Youl

    2011-01-01

    We present a comprehensive model of the dependence of the internal quantum efficiency (IQE) on both the temperature and the carrier density in InGaN-based blue and green light emitting diodes (LEDs). In our model, carriers are dominantly located and recombine both radiatively and nonradiatively inside randomly distributed In-rich areas of the InGaN quantum wells (QWs). In those areas, the carrier density is very high even at a small current density. We propose that the saturated radiative recombination rate is a primary factor determining the IQE droop of InGaN based LEDs. In typical InGaN-based QWs, it is common for the total carrier recombination rate to be smaller than the carrier injection rate even at a small current density. This is mostly attributable to the saturation of the radiative recombination rate. The saturation of the radiative recombination rate increases carrier density in InGaN QWs, enlarges nonradiative carrier losses, and eventually gives rise to the large IQE droop with increasing current. We show how the radiative recombination rate saturates and the radiative recombination rate has influence on the IQE droop in InGaN-based QW LEDs.

  11. Anti-tumor efficacy of lymphokine-activated killer cells and recombinant interleukin 2 in vivo: direct correlation between reduction of established metastases and cytolytic activity of lymphokine-activated killer cells

    International Nuclear Information System (INIS)

    Mule, J.J.; Yang, J.; Shu, S.; Rosenberg, S.A.

    1986-01-01

    Our previous studies demonstrated that the incubation of human peripheral blood lymphocytes or murine splenocytes in recombinant interleukin 2 (RIL 2) resulted in the generation of lymphokine-activated killer (LAK) cells capable of lysing a broad spectrum of fresh tumors in short-term chromium-release assays. Moreover, injections of LAK cells plus RIL 2 were highly effective in eliminating established 3 day metastases in the lung and liver. We have examined several parameters to define whether or not the cytolytic activity of LAK cells as measured in vitro correlated directly with the in vivo anti-tumor efficacy of adoptively transferred LAK cells. LAK cells plus RIL 2 could mediate marked reductions of established pulmonary metastases in mice rendered T cell deficient by adult thymectomy and lethal, total body irradiation followed by reconstitution with T cell-depleted bone marrow and spleen cells. Thus there was no requirement for additional T lymphocytes of host origin for successful therapy with adoptively transferred LAK cells plus RIL 2. Fresh splenocytes depleted of T cells by anti-Thy-1.2 monoclonal antibody plus complement generated LAK cells that were as highly lytic to fresh tumor in vitro and were as effective in reducing established pulmonary metastases as those generated from untreated or complement-treated splenocytes. Thus, the precursor to LAK cells with anti-tumor activity in vitro and in vivo did not express the Thy-1 antigenic marker. In contrast, treatment of LAK effector cells (those generated from a 3-day incubation of fresh, normal splenocytes in RIL 2) with anti-Thy-1.2 antibody plus complement reduced or abolished their in vitro cytolytic activity

  12. Recombination of cluster ions

    Science.gov (United States)

    Johnsen, Rainer

    1993-01-01

    Some of our recent work on molecular band emissions from recombination of molecular dimer ions (N4(+) and CO(+) CO) is discussed. Much of the experimental work was done by Y. S. Cao; the results on N4(+) recombination have been published. A brief progress report is given on our ongoing measurements of neutral products of recombination using the flowing-afterglow Langmuir-probe technique in conjunction with laser-induced fluorescence.

  13. Investigation of hydrogen-deformation interactions in β-21S titanium alloy using thermal desorption spectroscopy

    International Nuclear Information System (INIS)

    Tal-Gutelmacher, E.; Eliezer, D.; Boellinghaus, Th.

    2007-01-01

    The focus of this paper is the investigation of the combined influence of hydrogen and pre-plastic deformation on hydrogen's absorption/desorption behavior, the microstructure and microhardness of a single-phased β-21S alloy. In this study, thermal desorption analyses (TDS) evaluation of various desorption and trapping parameters provide further insight on the relationships between hydrogen absorption/desorption processes and deformation, and their mutual influence on the microstructure and the microhardness of β-21S alloy. TDS spectra were supported by other experimental techniques, such as X-ray diffraction, scanning and transmission electron microscopy, hydrogen quantity analyses and microhardness tests. Pre-plastic deformation, performed before the electrochemical hydrogenation of the alloy, increased significantly the hydrogen absorption capacity. Its influence was also evident on the notably expanded lattice parameter of β-21S alloy after hydrogenation. However, no hydride precipitation was observed. An interesting softening effect of the pre-deformed hydrogenated alloy was revealed by microhardness tests. TDS demonstrated the significant effect of pre-plastic deformation on the hydrogen evolution process. Hydrogen desorption temperature and the activation energy for hydrogen release increased, additional trap states were observed and the amount of desorbed hydrogen decreased

  14. Thermal desorption of deuterium implanted into beryllium

    International Nuclear Information System (INIS)

    Markin, A.V.; Chernikov, V.N.; Zakharov, A.P.

    1995-01-01

    By means of TDS measurements it is shown that the desorption of deuterium from Be implanted with 5 keV D ions to fluences, Φ, from 1x10 20 D/m 2 to 1x10 21 D/m 2 proceeds in one high temperature stage B, while at Φ ≥ 1.2x10 21 D/m 2 one more stage A is added. The desorption maximum A is narrow and consists of two peaks A 1 and A 2 at about 460 K and 490 K, respectively. Peak A 1 is attributed to the desorption of deuterium from the walls of opened channels formed under D ion implantation. Peak A 2 is a consequence of the opening of a part of closed bubbles/channels to the outer surface. The position of maximum B shifts noticeably and nonsteadily on the fluence in a range from 850 to 1050 K. The origin of this maximum is the liberation of D atoms bound at vacancy complexes discussed previously by Wampler. The dependence of Tm(B) on the fluence is governed by the interaction of freely migrating D atoms with partly opened or fully closed gas cavity arrangements which are created under temperature ramping, but differently in specimens implanted with D ions to different fluences

  15. Lead sorption-desorption from organic residues.

    Science.gov (United States)

    Duarte Zaragoza, Victor M; Carrillo, Rogelio; Gutierrez Castorena, Carmen M

    2011-01-01

    Sorption and desorption are mechanisms involved in the reduction of metal mobility and bioavailability in organic materials. Metal release from substrates is controlled by desorption. The capacity of coffee husk and pulp residues, vermicompost and cow manure to adsorb Pb2+ was evaluated. The mechanisms involved in the sorption process were also studied. Organic materials retained high concentrations of lead (up to 36,000 mg L(-1)); however, the mechanisms of sorption varied according to the characteristics of each material: degree of decomposition, pH, cation exchange capacity and percentage of organic matter. Vermicompost and manure removed 98% of the Pb from solution. Lead precipitated in manure and vermicompost, forming lead oxide (PbO) and lead ferrite (PbFe4O7). Adsorption isotherms did not fit to the typical Freundlich and Langmuir equations. Not only specific and non-specific adsorption was observed, but also precipitation and coprecipitation. Lead desorption from vermicompost and cow manure was less than 2%. For remediation of Pb-polluted sites, the application of vermicompost and manure is recommended in places with alkaline soils because Pb precipitation can be induced, whereas coffee pulp residue is recommended for acidic soils where Pb is adsorbed.

  16. Nano-nitride cathode catalysts of Ti, Ta, and Nb for polymer electrolyte fuel cells: Temperature-programmed desorption investigation of molecularly adsorbed oxygen at low temperature

    KAUST Repository

    Ohnishi, Ryohji; Takanabe, Kazuhiro; Katayama, Masao; Kubota, Jun; Domen, Kazunari

    2013-01-01

    -programmed desorption (TPD) of molecularly adsorbed O2 at 120-170 K from these nanoparticles was examined, and the resulting amount and temperature of desorption were key factors determining the ORR activity. The size-dependent TiN nanoparticles (5-8 and 100 nm) were

  17. Comparative field study: impact of laboratory assay variability on the assessment of recombinant factor IX Fc fusion protein (rFIXFc) activity.

    Science.gov (United States)

    Sommer, Jurg M; Buyue, Yang; Bardan, Sara; Peters, Robert T; Jiang, Haiyan; Kamphaus, George D; Gray, Elaine; Pierce, Glenn F

    2014-11-01

    Due to variability in the one-stage clotting assay, the performance of new factor IX (FIX) products should be assessed in this assay. The objective of this field study was to evaluate the accuracy of measuring recombinant FIX Fc fusion protein (rFIXFc) activity in clinical haemostasis laboratories using the one-stage clotting assay. Human haemophilic donor plasma was spiked with rFIXFc or BeneFIX® at 0.80, 0.20, or 0.05 IU/ml based on label potency. Laboratories tested blinded samples using their routine one-stage assay and in-house FIX plasma standard. The mean spike recoveries for BeneFIX (n=30 laboratories) were 121 %, 144 %, and 168 % of expected at nominal 0.80, 0.20, and 0.05 IU/ml concentrations, respectively. Corresponding rFIXFc spike recoveries were 88 %, 107 %, and 132 % of expected, respectively. All BeneFIX concentrations were consistently overestimated by most laboratories. rFIXFc activity was reagent-dependent; ellagic acid and silica gave higher values than kaolin, which underestimated rFIXFc. BeneFIX demonstrated significantly reduced chromogenic assay activity relative to one-stage assay results and nominal activity, while rFIXFc activity was close to nominal activity at three concentrations with better dilution linearity than the typical one-stage assay. In conclusion, laboratory- and reagent-specific assay variabilities were revealed, with progressively higher variability at lower FIX concentrations. Non-parallelism against the FIX plasma standard was observed in all one-stage assays with rFIXFc and BeneFIX, leading to significant overestimation of FIX activity at lower levels and generally high inter-laboratory variability. Compared to the accuracy currently achieved in clinical laboratories when measuring other rFIX products, most laboratories measured rFIXFc activity with acceptable accuracy and reliability using routine one-stage assay methods and commercially available plasma standards.

  18. Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid.

    Directory of Open Access Journals (Sweden)

    Yan Huang

    Full Text Available Glutamate decarboxylase (GAD catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA. In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C. Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C, superior thermostability (2.8-fold greater than that of GAD-C, and higher kcat/Km (1.6-fold higher than that of GAD-C. Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA.

  19. More efficient reversal of dabigatran inhibition of coagulation by activated prothrombin complex concentrate or recombinant factor VIIa than by four-factor prothrombin complex concentrate.

    Science.gov (United States)

    Lindahl, Tomas L; Wallstedt, Maria; Gustafsson, Kerstin M; Persson, Egon; Hillarp, Andreas

    2015-03-01

    The number of patients on antithrombotic treatment due to atrial fibrillation and venous thromboembolism is increasing fast due to an aging population. A growing proportion will be treated with novel oral anticoagulants, the first in clinical use was the direct oral thrombin inhibitor dabigatran (Pradaxa®). A small percentage of the patients on dabigatran will experience serious bleeding or be in need of urgent surgery. The aim of this study was to test the effects of different hemostatic agents in potentially reversing the anticoagulant effects in vitro in blood or platelet-rich plasma (PRP) spiked with dabigatran. Whole blood or PRP was spiked with the active substance dabigatran, 200 μg/L. We measured clotting time being induced by 1.4 pmol/L tissue factor using the instrument ReoRox2™ and initial clot growth velocity from a tissue factor covered surface using the instrument Thrombodynamics Analyzer T-2™. Dabigatran prolonged clotting time 5-fold but reduced clot growth velocity only slightly. The reversing effects of prothrombin complex concentrates (PCC), activated PCC (APCC) and recombinant activated factor VII (rFVIIa) were then tested. APCC (1.8 U/mL) reduced the prolonged clotting time by 1/3, rFVIIa (2 μg/L) only slightly (n = 10-20). The reduction was not significant using Mann-Whitney test but significant using t-test with Bonferronis' correction for multiple comparisons, whereas PCC (0.56 U/mL) had no effect on clotting time. APCC doubled initial clot growth velocity, although even more in the absence of dabigatran. In conclusion, APCC and rFVIIa, but not PCC, seem to reverse, at least partially, some effects of dabigatran on coagulation parameters. Systematic evaluation of case reports, registries and, ultimately, randomized clinical trials are needed to elucidate potential benefit for patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. WATER ADSORPTION AND DESORPTION ISOTHERMS ON MILK POWDER: II. WHOLE MILK

    Directory of Open Access Journals (Sweden)

    Edgar M. Soteras

    2014-03-01

    Full Text Available The aim of this research was the determination of adsorption and desorption isotherms of cow whole milk powder. The experiments have been carried out at 15, 25 and 40 ºC, in ranges of moisture and water activity characteristic of normal conditions in which the processes of drying, packaging and storage are developed. By studying the influence of the temperature on the experimental plots, the isosteric adsorption heat was determined. Experimental data were correlated to the referential model of Guggenheim, Anderson and Boer (GAB. For both, adsorption and desorption, a good model fit was observed. The isotherms showed very similar shapes between them and, by comparing adsorption and desorption isotherms, the phenomenon of hysteresis was confirmed.

  1. ε-Polylysine-based thermo-responsive adsorbents for immunoglobulin adsorption-desorption under mild conditions.

    Science.gov (United States)

    Maruyama, Masashi; Shibuya, Keisuke

    2017-08-22

    Thermo-responsive adsorbents for immunoglobulin G (IgG) employing ε-polylysine (EPL) as a polymer backbone were developed. The introduction of mercaptoethylpyridine (MEP) as an IgG-binding ligand and hydrophobization of side chains afforded thermo-responsive IgG adsorbents, whose thermo-responsive IgG desorption ratio was up to 88% (EPL/MEP derivative 3m). The changes in surface densities of active MEP groups, which are caused by thermal conformational changes of the adsorbents, play key roles for IgG desorption. Although a trade-off of IgG adsorption capacity and IgG desorption ratio was observed, the present study offers a novel molecular design for thermo-responsive adsorbents with high synthetic accessibility and potentially low toxicity.

  2. X-ray induced gas desorption within a prototype LEP vacuum chamber

    International Nuclear Information System (INIS)

    Williams, E.M.; Le Normand, F.; Hilleret, N.; Dominichini, G.

    1982-12-01

    The present report is concerned with an experimental simulation of the process of photon induced desorption within an aluminium vacuum chamber of the same basic form as proposed for the LEP accelerator. The objectives in the work can be described in the following three-fold manner: Firstly, to establish the levels of photon induced desorption efficiency for identified gas species. Secondly, to examine the contribution of surface treatments as bakeout and glow discharge cleaning, and to correlate these responses with changes in surface activity induced by beam cleaning. Thirdly, to gain insight into the energy dependence of the desorption process so as to provide a reasonable basis for predicting conditions at the levels of critical energy in excess of 100 keV which are applicable at the full design energy of the LEP accelerator. (orig./HSI)

  3. [Managment of subretinal heamorrhages within the macular area using intravitreal injections of recombined tissue plasminogen activator, sulphur hexafluoride and ranihizumab--preliminary report].

    Science.gov (United States)

    Miniewicz, Joanna; Kubicka-Trząska, Agnieszka; Karska-Basta, Izabella; Romanowska-Dixon, Boźena

    2015-01-01

    Submacular hemorrhages cause serious vision impairment. Patient observation, waiting for the spontaneous blood reabsorption and resolution of the haemorrhage leads to the severe damage to retinal tissue as a result of scar formation. The paper presents 7 cases of patients with submacular haemorrhages treated with intravitreal injections of recombined tissue plasminogen activator (rtPA) and sulphur hexafluoride (SFG). In 4 cases, the haemorrhage was secondary to AMD, in two cases to trauma, and it was idiopathic in one case. All patients were treated with intravitreal injections of rtPA and SF6 for thrombolysis and pneumatic displacement of haemorrhage outside macular structures. Ranibizumab was additionally administered to patients with age-related macular degeneration. Such treatment improved visual acuity in all patients, reducing the central retinal thickness as shown in follow-up optical coherence tomography. The presented treatment of submacular hemorrhages with intravitreal injections of rtPA and SF6 provided good results, but in order to develop a standard management algorithm for this disease, the analysis of larger patient sample is required.

  4. Cost-utility analysis of an adjunctive recombinant activated factor VIIa for on-demand treatment of bleeding episodes in dengue haemorrhagic fever.

    Science.gov (United States)

    Naing, Cho; Poovorawan, Yong; Mak, Joon Wah; Aung, Kyan; Kamolratankul, Pirom

    2015-06-01

    The present study aimed to assess the cost-utility analysis of using an adjunctive recombinant activated factor VIIa (rFVIIa) in children for controlling life-threatening bleeding in dengue haemorrhagic fever (DHF)/dengue shock syndrome (DSS). We constructed a decision-tree model, comparing a standard care and the use of an additional adjuvant rFVIIa for controlling life-threatening bleeding in children with DHF/DSS. Cost and utility benefit were estimated from the societal perspective. The outcome measure was cost per quality-adjusted life years (QALYs). Overall, treatment with adjuvant rFVIIa gained QALYs, but the total cost was higher. The incremental cost-utility ratio for the introduction of adjuvant rFVIIa was $4241.27 per additional QALY. Sensitivity analyses showed the utility value assigned for calculation of QALY was the most sensitive parameter. We concluded that despite high cost, there is a role for rFVIIa in the treatment of life-threatening bleeding in patients with DHF/DSS.

  5. Effects of Paracetamol on NOS, COX, and CYP Activity and on Oxidative Stress in Healthy Male Subjects, Rat Hepatocytes, and Recombinant NOS

    Science.gov (United States)

    Trettin, Arne; Böhmer, Anke; Suchy, Maria-Theresia; Probst, Irmelin; Staerk, Ulrich; Stichtenoth, Dirk O.; Frölich, Jürgen C.

    2014-01-01

    Paracetamol (acetaminophen) is a widely used analgesic drug. It interacts with various enzyme families including cytochrome P450 (CYP), cyclooxygenase (COX), and nitric oxide synthase (NOS), and this interplay may produce reactive oxygen species (ROS). We investigated the effects of paracetamol on prostacyclin, thromboxane, nitric oxide (NO), and oxidative stress in four male subjects who received a single 3 g oral dose of paracetamol. Thromboxane and prostacyclin synthesis was assessed by measuring their major urinary metabolites 2,3-dinor-thromboxane B2 and 2,3-dinor-6-ketoprostaglandin F1α, respectively. Endothelial NO synthesis was assessed by measuring nitrite in plasma. Urinary 15(S)-8-iso-prostaglanding F2α was measured to assess oxidative stress. Plasma oleic acid oxide (cis-EpOA) was measured as a marker of cytochrome P450 activity. Upon paracetamol administration, prostacyclin synthesis was strongly inhibited, while NO synthesis increased and thromboxane synthesis remained almost unchanged. Paracetamol may shift the COX-dependent vasodilatation/vasoconstriction balance at the cost of vasodilatation. This effect may be antagonized by increasing endothelial NO synthesis. High-dosed paracetamol did not increase oxidative stress. At pharmacologically relevant concentrations, paracetamol did not affect NO synthesis/bioavailability by recombinant human endothelial NOS or inducible NOS in rat hepatocytes. We conclude that paracetamol does not increase oxidative stress in humans. PMID:24799980

  6. Towards vaccine against toxoplasmosis: evaluation of the immunogenic and protective activity of recombinant ROP5 and ROP18 Toxoplasma gondii proteins.

    Science.gov (United States)

    Grzybowski, Marcin M; Dziadek, Bożena; Gatkowska, Justyna M; Dzitko, Katarzyna; Długońska, Henryka

    2015-12-01

    Toxoplasmosis is one of the most common parasitic infections worldwide. An effective vaccine against human and animal toxoplasmosis is still needed to control this parasitosis. The polymorphic rhoptry proteins, ROP5 and ROP18, secreted by Toxoplasma gondii during the invasion of the host cell have been recently considered as promising vaccine antigens, as they appear to be the major determinants of T. gondii virulence in mice. The goal of this study was to evaluate their immunogenic and immunoprotective activity after their administration (separately or both recombinant proteins together) with the poly I:C as an adjuvant. Immunization of BALB/c and C3H/HeOuJ mice generated both cellular and humoral specific immune responses with some predominance of IgG1 antibodies. The spleen cells derived from vaccinated animals reacted to the parasite's native antigens. Furthermore, the immunization led to a partial protection against acute and chronic toxoplasmosis. These findings confirm the previous assumptions about ROP5 and ROP18 antigens as valuable components of a subunit vaccine against toxoplasmosis.

  7. A recombinant bivalent fusion protein rVE confers active and passive protection against Yersinia enterocolitica infection in mice.

    Science.gov (United States)

    Singh, Amit Kumar; Kingston, Joseph Jeyabalaji; Murali, Harishchandra Sripathy; Batra, Harsh Vardhan

    2014-03-05

    In the present study, a bivalent chimeric protein rVE comprising immunologically active domains of Yersinia pestis LcrV and YopE was assessed for its prophylactic abilities against Yersinia enterocolitica O:8 infection in murine model. Mice immunized with rVE elicited significantly higher antibody titers with substantial contribution from the rV component (3:1 ratio). Robust and significant resistance to Y. enterocolitica infection with 100% survival (Penterocolitica O:8 against the 75%, 60% and 75% survival seen in mice immunized with rV, rE, rV+rE, respectively. Macrophage monolayer supplemented with anti-rVE polysera illustrated efficient protection (89.41% survival) against challenge of Y. enterocolitica O:8. In contrast to sera from sham-immunized mice, immunization with anti-rVE polysera provided complete protection to BALB/c mice against I.P. challenge with 10(8)CFU of Y. enterocolitica O:8 and developed no conspicuous signs of infection in necropsy. The histopathological analysis of microtome sections confirmed significantly reduced lesion size or no lesion in liver and intestine upon infection in anti-rVE immunized mice. The findings from this study demonstrated the fusion protein rVE as a potential candidate subunit vaccine and showed the functional role of antibodies in protection against Y. enterocolitica infections. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Measuring hydrophobic micropore volumes in geosorbents from trichloroethylene desorption data.

    Science.gov (United States)

    Cheng, Hefa; Reinhard, Martin

    2006-06-01

    Hydrophobic micropores can play a significant role in controlling the long-term release of organic contaminants from geosorbents. We describe a technique for quantifying the total and the hydrophobic mineral micropore volumes based on the mass of trichloroethylene (TCE) sorbed in the slow-releasing pores under dry and wet conditions, respectively. Micropore desorption models were used to differentiate the fast- and slow-desorbing fractions in desorption profiles. The micropore environment in which organic molecules were sorbed in the presence of water was probed by studying the transformation of a water-reactive compound (2,2-dichloropropane or 2,2-DCP). For sediment from an alluvial aquifer, the total and hydrophobic micropore volumes estimated using this technique were 4.65 microL/g and 0.027 microL/g (0.58% of total), respectively. In microporous silica gel A, a hydrophobic micropore volume of 0.038 microL/g (0.035% of reported total) was measured. The dehydrohalogenation rate of 2,2-DCP sorbed in hydrophobic micropores of the sediment was slower than that reported in bulk water, indicating an environment of low water activity. The results suggest that hydrolyzable organic contaminants sorbed in hydrophobic micropores react slower than in bulk water, consistent with the reported persistence of reactive contaminants in natural soils.

  9. Adsorption and desorption of 14C-chlorsulfuron in soils

    International Nuclear Information System (INIS)

    Chen Zuyi; Cheng Wei; Mi Chunyun

    1995-01-01

    The adsorption and desorption of the 4 concentrations of 14 C-chlorsulfuron in 10 soils were studied. As a result the soils had weak adsorptions of chlorsulfuron and the adsorptions varied with different type of soils tested. Adsorption rate of paddy soil (infant red earth) from Hunan and latosol red earth from Hainan was 3%∼4%; Yellow-brown earth from Nanjing and red earth from Jiangxi was 6%∼9%; black soil from Jilin, paddy soil (infant red earth) from Jiangxi and red earth from Anhui was 10%∼14%; Albic bleached soil from Jilin and yellow fluvo-aquatic soil from Jiangsu was 19%∼23%. pH value had an influence on the adsorption and organic matter had not obvious influence on the adsorption. Chlorsulfuron absorbed in soil could be desorbed through water. The relation between the adsorption and desorption was negative. The weak adsorption in soil shows that chlorsulfuron is active movable and diffusible and likely to pollute the ecological environment

  10. In-vivo biological activity and glycosylation analysis of a biosimilar recombinant human follicle-stimulating hormone product (Bemfola compared with its reference medicinal product (GONAL-f.

    Directory of Open Access Journals (Sweden)

    Renato Mastrangeli

    Full Text Available Recombinant human follicle-stimulating hormone (r-hFSH is widely used in fertility treatment. Although biosimilar versions of r-hFSH (follitropin alfa are currently on the market, given their structural complexity and manufacturing process, it is important to thoroughly evaluate them in comparison with the reference product. This evaluation should focus on how they differ (e.g., active component molecular characteristics, impurities and potency, as this could be associated with clinical outcome. This study compared the site-specific glycosylation profile and batch-to-batch variability of the in-vivo bioactivity of Bemfola, a biosimilar follitropin alfa, with its reference medicinal product GONAL-f. The focus of this analysis was the site-specific glycosylation at asparagine (Asn 52 of the α-subunit of FSH, owing to the pivotal role of Asn52 glycosylation in FSH receptor (FSHR activation/signalling. Overall, Bemfola had bulkier glycan structures and greater sialylation than GONAL-f. The nominal specific activity for both Bemfola and GONAL-f is 13,636 IU/mg. Taking into account both the determined potency and the nominal amount the average specific activity of Bemfola was 14,522 IU/mg (105.6% of the nominal value, which was greater than the average specific activity observed for GONAL-f (13,159 IU/mg; 97.3% of the nominal value; p = 0.0048, although this was within the range stated in the product label. A higher batch-to-batch variability was also observed for Bemfola versus GONAL-f (coefficient of variation: 8.3% vs 5.8%. A different glycan profile was observed at Asn52 in Bemfola compared with GONAL-f (a lower proportion of bi-antennary structures [~53% vs ~77%], and a higher proportion of tri-antennary [~41% vs ~23%] and tetra-antennary structures [~5% vs <1%]. These differences in the Asn52 glycan profile might potentially lead to differences in FSHR activation. This, together with the greater bioactivity and higher batch-to-batch variability

  11. Optical detection of CO and CO2 temperature dependent desorption from carbon nanotube clusters

    International Nuclear Information System (INIS)

    Chistiakova, M V; Armani, A M

    2014-01-01

    The development of new materials relies on high precision methods to quantify adsorption/desorption of gases from surfaces. One commonly used approach is temperature programmed desorption spectroscopy. While this approach is very accurate, it requires complex instrumentation, and it is limited to performing experiments under high vacuum, thus restricting experimental scope. An alternative approach is to integrate the surface of interest directly onto a detector face, creating an active substrate. One surface that has applications in numerous areas is the carbon nanotube (CNT). As such, an active substrate that integrates a CNT surface on a sensor and is able to perform measurements in ambient environments will have significant impact. In the present work, we have developed an active substrate that combines an optical sensor with a CNT cluster substrate. The optical sensor is able to accurately probe the temperature dependent desorption of carbon monoxide and carbon dioxide gases from the CNT cluster surface. This active substrate will enable a wide range of temperature dependent desorption measurements to be performed from a scientifically interesting material system. (paper)

  12. Molecular dynamics study of the coverage dependence of Xe desorption from Pt(111)

    NARCIS (Netherlands)

    Jansen, A.P.J.

    1992-01-01

    Mol. dynamics simulations with periodic boundary conditions are used to calc. temp.-programmed desorption spectra of Xe/Pt(111). The activation barrier is overcome by using the compensating Hamiltonian method. Monte Carlo simulations are used to correct for the finite size of the simulated system. A

  13. Laser induced desorption as hydrogen retention diagnostic method

    Energy Technology Data Exchange (ETDEWEB)

    Zlobinski, Miroslaw

    2016-07-15

    Laser Induced Desorption Spectroscopy (LIDS) is a diagnostic method to measure the hydrogen content in the surface of a material exposed to a hydrogen isotope (H,D,T) plasma. It is developed mainly to monitor hydrogen retention in the walls of magnetic fusion devices that have to limit the amount of their fuel tritium mainly due to safety reasons. The development of fusion increasingly focusses on plasma-wall interactions for which in situ diagnostics like LIDS are required that work during plasma operation and without tile removal. The method has first been developed for thin amorphous hydrocarbon (a-C:H < 500 nm) layers successfully and is studied in the present work on thick (15 μm) layers, carbon fibre composites (CFCs), bulk tungsten (W), W fuzz and mixed C/W materials. In LID a 3 ms Nd:YAG (1064 nm) laser pulse heats a spot of diameter 3 mm with 500 {sup MW}/{sub m{sup 2}} on W to 1800 K at the surface and thus above 1300 K within ca. 0.2 mm depth. On C materials (graphite, CFC, a-C:H) this temperature guarantees a nearly complete (>95%) desorption already within 1.5 ms pulse duration. The retained hydrogen atoms are desorbed locally, recombine to molecules and migrate promptly to the surface via internal channels like pores and grain boundaries. Whereas, in W the retained hydrogen atoms have to diffuse through the bulk material, which is a relatively slow process also directed into the depth. The desorbed hydrogen fraction can thus be strongly reduced to 18-91% as observed here. This fraction is measured by melting the central part of a previously heated spot ca. 40 μm deep with a diameter 2 mm, 3 ms laser pulse, releasing the remaining hydrogen. W samples exposed to different plasmas in TEXTOR, Pilot-PSI, PSI-2, PADOS and PlaQ show that the desorption fraction of LID mainly decreases due to higher sample temperature during plasma exposure. The heat causes deeper hydrogen diffusion and/or stronger hydrogen trapping due to creation of traps with higher

  14. Laser induced desorption as hydrogen retention diagnostic method

    International Nuclear Information System (INIS)

    Zlobinski, Miroslaw

    2016-01-01

    Laser Induced Desorption Spectroscopy (LIDS) is a diagnostic method to measure the hydrogen content in the surface of a material exposed to a hydrogen isotope (H,D,T) plasma. It is developed mainly to monitor hydrogen retention in the walls of magnetic fusion devices that have to limit the amount of their fuel tritium mainly due to safety reasons. The development of fusion increasingly focusses on plasma-wall interactions for which in situ diagnostics like LIDS are required that work during plasma operation and without tile removal. The method has first been developed for thin amorphous hydrocarbon (a-C:H < 500 nm) layers successfully and is studied in the present work on thick (15 μm) layers, carbon fibre composites (CFCs), bulk tungsten (W), W fuzz and mixed C/W materials. In LID a 3 ms Nd:YAG (1064 nm) laser pulse heats a spot of diameter 3 mm with 500 MW / m 2 on W to 1800 K at the surface and thus above 1300 K within ca. 0.2 mm depth. On C materials (graphite, CFC, a-C:H) this temperature guarantees a nearly complete (>95%) desorption already within 1.5 ms pulse duration. The retained hydrogen atoms are desorbed locally, recombine to molecules and migrate promptly to the surface via internal channels like pores and grain boundaries. Whereas, in W the retained hydrogen atoms have to diffuse through the bulk material, which is a relatively slow process also directed into the depth. The desorbed hydrogen fraction can thus be strongly reduced to 18-91% as observed here. This fraction is measured by melting the central part of a previously heated spot ca. 40 μm deep with a diameter 2 mm, 3 ms laser pulse, releasing the remaining hydrogen. W samples exposed to different plasmas in TEXTOR, Pilot-PSI, PSI-2, PADOS and PlaQ show that the desorption fraction of LID mainly decreases due to higher sample temperature during plasma exposure. The heat causes deeper hydrogen diffusion and/or stronger hydrogen trapping due to creation of traps with higher binding energy

  15. Identification, cloning and lactonase activity of recombinant protein of N-acyl homoserine lactonase (AiiA from Bacillus thuringiensis 147-115-16 strain.

    Directory of Open Access Journals (Sweden)

    Alvaro Mauricio Florez Escobar

    2014-01-01

    Short title: N-acyl homoserine lactonase (AiiA from Bacillus thuringiensis  Abstract: The quorum-quenching N-acyl homoserine lactonases are a family of bacterial metalloenzymes that participate in degradation of N-acyl homoserine lactones (AHLs, disrupting the quorum sensing system of gram negative bacterial species. From a collection of Bacillus thuringiensis strains isolated in Colombia from plants and exhibiting toxic activity against lepidopteran insects, 310 bacterial isolates were tested to determine lactonase activity by using biosensor systems in presence of synthetic N-hexanoyl-L-homoserine lactone (C6-HSL and N-octanoyl-L-homoserine lactone (C8-HSL. From them, 251 strains showed degrading activity to both C6-HSL and C8-HSL, 57% exhibited degrading activity to C6-HSL and 43% to C8-HSL. One B. thuringiensis strain, denoted as 147-115-16, that exhibit high degrading activity to C6-HSL and C8-HSL, was able to attenuate soft rot symptoms in infected potato slices with Pectobacterium carotovorum. This strain contains an homologous of the aiiA gene that was cloned, sequenced and expressed in Esherichia coli DE3. The recombinant protein AiiA147-11516 displays activity to C6-HSL, C8-HSL, N-(β-ketocaproyl (3-O-C6-HSL and N-3-oxo-dodecanoyl (3-O-C12-HSL. The recombinant strain in the presence of P. caratovorum cultures was able to attenuate the infection, suggesting that it interferes either with the accumulation or with the response to the AHLs signals. Acording to this data and based on previous report from recombinant AiiA147-11516, this enzyme exhibits activity to a wide range of catalytic substrates suggesting its industrial application in the disease control programs through plants transformation. Key words: lactones, Quorum sensing, Quorum quenching, Lactonases, Pectobacterium caratovorum Resumen: Las N-acíl homoserina lactonasas son una familia de metaloenzimas bacterianas que participan en la degradación de N-acil homoserina lactonas (AHLs

  16. Improved thermostability and enzyme activity of a recombinant phyA mutant phytase from Aspergillus niger N25 by directed evolution and site-directed mutagenesis.

    Science.gov (United States)

    Tang, Zizhong; Jin, Weiqiong; Sun, Rong; Liao, Yan; Zhen, Tianrun; Chen, Hui; Wu, Qi; Gou, Lin; Li, Chenlei

    2018-01-01

    We previously constructed three recombinant phyA mutant strains (PP-NP m -8, PP-NP ep -6A and I44E/T252R-PhyA), showing improved catalytic efficiency or thermostability of Aspergillus niger N25 phytase, by error-prone PCR or site-directed mutagenesis. In this study, directed evolution and site-directed mutagenesis were further applied to improve the modified phytase properties. After one-round error-prone PCR for phytase gene of PP-NP ep -6A, a single transformant, T195L/Q368E/F376Y, was obtained with the significant improvements in catalytic efficiency and thermostability. The phytase gene of T195L/Q368E/F376Y, combined with the previous mutant phytase genes of PP-NP ep -6A, PP-NP m -8 and I44E/T252R-PhyA, was then sequentially modified by DNA shuffling. Three genetically engineered strains with desirable properties were then obtained, namedQ172R, Q172R/K432R andQ368E/K432R. Among them, Q172R/K432R showed the highest thermostability with the longest half-life and the greatest remaining phytase activity after heat treatment, while Q368E/K432R showed the highest catalytic activity. Five substitutions (Q172R, T195L, Q368E, F376Y, K432R) identified from random mutagenesis were added sequentially to the phytase gene of PP-NP ep -6A to investigate how the mutant sites influence the properties of phytase. Characterization and structural analysis demonstrated that these mutations could produce cumulative or synergistic improvements in thermostability or catalytic efficiency of phytase. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Loss of Resistance to Angiotensin II-Induced Hypertension in the Jackson Laboratory Recombination-Activating Gene Null Mouse on the C57BL/6J Background.

    Science.gov (United States)

    Ji, Hong; Pai, Amrita V; West, Crystal A; Wu, Xie; Speth, Robert C; Sandberg, Kathryn

    2017-06-01

    Resistance to angiotensin II (Ang II)-induced hypertension in T-cell-deficient male mice with a targeted mutation in the recombination-activating gene-1 ( Rag1 ) on the C57BL/6J background (B6. Rag1 -/- -M), which was reported by 5 independent laboratories including ours before 2015, has been lost. In mice purchased from Jackson Laboratory in 2015 and 2016, the time course and magnitude increase in mean arterial pressure induced by 2 weeks of Ang II infusion at 490 ng/kg per minute was identical between B6. Rag1 -/- -M and male wild-type littermates. Moreover, there were no differences in the time course or magnitude increase in mean arterial pressure at the lowest dose of Ang II (200 ng/kg per minute) that increased mean arterial pressure. This loss in Ang II resistance is independent of T cells. Angiotensin type 1-receptor binding was 1.4-fold higher in glomeruli isolated from recently purchased B6. Rag1 -/- -M suggesting an increase in renal angiotensin type 1-receptor activity masks the blood pressure protection afforded by the lack of T cells. The phenotypic change in B6. Rag1 -/- -M has implications for investigators using this strain to study mechanisms of T-cell modulation of Ang II-dependent blood pressure control. These findings also serve as a reminder that the universal drive for genetic variation occurs in all animals including inbred mouse strains and that spontaneous mutations leading to phenotypic change can compromise experimental reproducibility over time and place. Finally, these observations illustrate the importance of including experimental details about the location and time period over which animals are bred in publications involving animal studies to promote rigor and reproducibility in the scientific literature. © 2017 American Heart Association, Inc.

  18. In vivo distribution of Tc-99m labeled recombinant tissue-type plasminogen activator in control and thrombus-bearing rats

    International Nuclear Information System (INIS)

    Tsukamoto, Eriko

    1992-01-01

    In vivo distribution of Tc-99m labeled recombinant tissue-type plasminogen activator (Tc-99m-rt-PA) was studied in control rats and thrombus-bearing rats. To compare fibrin binding in vivo with that in vitro, Tc-99m-rt-PA binding to fibrin gel in vitro was also imaged. Rapid blood clearance and accumulation into the liver and kidneys were observed in both control and thrombus-bearing rats. Accumulation in the stomach, which indicates instability of labeled rt-PA in vivo, was very low until two hours after injection. Tc-99m-rt-PA accumulation in the clots was higher than that in skeletal and heart muscles, although it was lower than in blood, liver, and kidneys. Administration of aprotinin, an antifibrinolytic agent, significantly prolonged clot accumulation of Tc-99m-rt-PA at 30 minutes after injection. These results suggest that fibrinolysis is responsible for the low rt-PA concentration in the clots. A scintigram of a thrombus-bearing rat demonstrated increased radioactivity at the clot forming site. On the other hand, Tc-99m-labeled human albumin, which was used as a control, was not accumulated in the clot. Tc-99m-rt-PA binding to fibrin gel in vitro was clearly imaged. By comparison, in vivo fibrin binding of Tc-99m-rt-PA was much lower than in vitro. The reasons for low thrombus uptake in vivo may be: (1) biochemical inactivation of extrinsically administered rt-PA by t-PA inhibitor; (2) fibrinolysis by rt-PA activated plasminogen. Overcoming these limitations will enable Tc-99m-rt-PA to reach the stage of clinical trials. (author)

  19. Recombinant Tissue Plasminogen Activator Induces Neurological Side Effects Independent on Thrombolysis in Mechanical Animal Models of Focal Cerebral Infarction: A Systematic Review and Meta-Analysis.

    Directory of Open Access Journals (Sweden)

    Mei-Xue Dong

    Full Text Available Recombinant tissue plasminogen activator (rtPA is the only effective drug approved by US FDA to treat ischemic stroke, and it contains pleiotropic effects besides thrombolysis. We performed a meta-analysis to clarify effect of tissue plasminogen activator (tPA on cerebral infarction besides its thrombolysis property in mechanical animal stroke.Relevant studies were identified by two reviewers after searching online databases, including Pubmed, Embase, and ScienceDirect, from 1979 to 2016. We identified 6, 65, 17, 12, 16, 12 and 13 comparisons reporting effect of endogenous tPA on infarction volume and effects of rtPA on infarction volume, blood-brain barrier, brain edema, intracerebral hemorrhage, neurological function and mortality rate in all 47 included studies. Standardized mean differences for continuous measures and risk ratio for dichotomous measures were calculated to assess the effects of endogenous tPA and rtPA on cerebral infarction in animals. The quality of included studies was assessed using the Stroke Therapy Academic Industry Roundtable score. Subgroup analysis, meta-regression and sensitivity analysis were performed to explore sources of heterogeneity. Funnel plot, Trim and Fill method and Egger's test were obtained to detect publication bias.We found that both endogenous tPA and rtPA had not enlarged infarction volume, or deteriorated neurological function. However, rtPA would disrupt blood-brain barrier, aggravate brain edema, induce intracerebral hemorrhage and increase mortality rate.This meta-analysis reveals rtPA can lead to neurological side effects besides thrombolysis in mechanical animal stroke, which may account for clinical exacerbation for stroke patients that do not achieve vascular recanalization with rtPA.

  20. Clinical use of recombinant human activated factor VII (rFVIIa in the prevention and treatment of bleeding episodes in patients with Glanzmann’s thrombasthenia

    Directory of Open Access Journals (Sweden)

    Man-Chiu Poon

    2007-11-01

    Full Text Available Man-Chiu PoonDepartments of Medicine, Pediatrics and Oncology and Southern Alberta Bleeding Disorders Clinic, University of Calgary and Calgary Health Region, Calgary, Alberta, CanadaAbstract: Glanzmann’s thrombasthenia (GT is a congenital qualitative platelet disorders due to the deficiency or defect of platelet membrane GPIIb/IIIa (integrin αIIbβ3. The standard treatment for bleeding is platelet transfusion but repeated transfusion may result in the development of anti-platelet antibodies (to HLA and/or GPIIbIIIa rendering future platelet transfusion ineffective. Alternative effective agent(s are needed. There are increasing reports documenting efficacy of high dose rFVIIa in GT patients with adverse events uncommon. The efficacy is supported by evidence that high concentration FVIIa binds to activated platelet surface and improves thrombin generation to enhance deposition (adhesion and aggregation of platelets lacking GPIIb/IIIa. While there are increasing clinical experiences, evidence-based clinical data are not available. There is a need for more clinical studies, particularly clinical trials, to further assess the efficacy, safety (particularly thrombotic events and optimal regimen of rFVIIa in GT patients, either singly or in combination with other hemostatic agents such as platelet transfusion. In the absence of this data, for treatment of severe bleeding in GT patients with platelet antibodies and platelet refractoriness, rFVIIa at dose 90 μg/kg every 2 h for 3 or more doses could be considered. This more “optimal regimen” derived from a recent International Survey needs confirmation with larger studies. What the optimal regimen for surgical coverage is remains unresolved.Keywords: Glanzmann’s thrombasthenia, recombinant human activated factor VII (rFVIIa, bleeding, surgery, platelet transfusion, GPIIb/IIIa

  1. Containment air circulation for optimal hydrogen recombination

    International Nuclear Information System (INIS)

    Spinks, N.; Krause, M.

    1997-01-01

    An accepted first-line defense for hydrogen mitigation is to design for the hydrogen to be rapidly mixed with the containment atmosphere and diluted to below flammability concentrations. Then, as hydrogen continues to be produced in the longer term, recombiners can be used to remove hydrogen: recombiners can be located in forced-air ducts or passive recombiners can be distributed within containment and the heat of recombination used to promote local air circulation. However, this principle does not eliminate the possibility of high hydrogen concentrations at locations removed from the recombiners. An improvement on this strategy is to arrange for a specific, buoyancy-driven, overall circulation of the containment atmosphere such that the recombiners can be located within the recirculation flow, immediately downstream of the hydrogen source. This would make the mixing process more predictable and solve the mass-transfer problem associated with distributed recombiners. Ideally, the recombiners would be located just above the hydrogen source so that the heat of recombination would assist the overall circulation. In this way, the hydrogen would be removed as close as possible to the source, thereby minimizing the amount of hydrogen immediately downstream of the source and reducing the hydrogen concentration to acceptable levels at other locations. Such a strategy requires the containment volume to be divided into an upflow path, past the hydrogen source and the recombiner, and a downflow path to complete the circuit. The flow could be generated actively using fans or passively using buoyancy forces arising from the difference in density of gases in the upfiow and downflow paths; the gases in the downflow path being cooled at an elevated heat sink. (author)

  2. Thermal desorption spectroscopy of pyrolytic graphite cleavage faces after keV deuterium irradiation at 330-1000 K

    International Nuclear Information System (INIS)

    Gotoh, Y.; Yamaki, T.; Tokiguchi, K.

    1992-01-01

    Thermal desorption spectroscopy (TDS) measurements were made on D 2 and CD 4 from surface layers of pyrolytic graphite cleavage faces after 3 keV D + 3 irradiation to 1.5 x 10 18 D/cm 2 at irradiation temperatures from 330 to 1000 K. Thermal desorption of both D 2 and CD 4 was observed to rise simultaneously at around 700 K. The D 2 peak was found at T m = 900-1000 K, while the CD 4 peak appeared at a lower temperature, 800-840 K. The T m for the D 2 TDS increased, while that for the CD 4 decreased with increasing irradiation temperature. These results obviously indicate that the D 2 desorption is detrapping/recombination limited, while the CD 4 desorption is most likely to be diffusion limited. The amount of thermally desorbed D 2 after the D + irradiation was observed to monotonously decrease as the irradiation temperature was increased from 330 to 1000 K. These tendencies agreed with previous results for the irradiation temperature dependencies of both C1s chemical shift (XPS) and the interlayer spacing, d 002 (HRTEM), on the graphite basal face. (orig.)

  3. Thermal desorption and surface modification of He+ implanted into tungsten

    International Nuclear Information System (INIS)

    Fu Zhang; Yoshida, N.; Iwakiri, H.; Xu Zengyu

    2004-01-01

    Tungsten divertor plates in fusion reactors will be subject to helium bombardment. Helium retention and thermal desorption is a concerned issue in controlling helium ash. In the present study, fluence dependence of thermal desorption behavior of helium in tungsten was studied at different irradiation temperatures and ion energies. Results showed that helium desorption could start at ∼400 K with increasing fluence, while no noticeable peaks were detected at low fluence. Total helium desorption reached a saturation value at high fluence range, which was not sensitive to irradiation temperature or ion energy for the conditions evaluated. Surface modifications caused by either ion irradiation or thermal desorption were observed by SEM. The relationship of surface modifications and helium desorption behavior was discussed. Some special features of elevated irradiation temperature and lower ion energy were also indicated

  4. Interactions on External MOF Surfaces: Desorption of Water and Ethanol from CuBDC Nanosheets.

    Science.gov (United States)

    Elder, Alexander C; Aleksandrov, Alexandr B; Nair, Sankar; Orlando, Thomas M

    2017-10-03

    The external surfaces of metal-organic framework (MOF) materials are difficult to experimentally isolate due to the high porosities of these materials. MOF surface surrogates in the form of copper benzenedicarboxylate (CuBDC) nanosheets were synthesized using a bottom-up approach, and the surface interactions of water and ethanol were investigated by temperature-programmed desorption (TPD). A method of analysis of diffusion-influenced TPD was developed to measure the desorption properties of these porous materials. This approach also allows the extraction of diffusion coefficients from TPD data. The transmission Fourier transform infrared spectra, powder X-ray diffraction patterns, and TPD data indicate that water desorbs from CuBDC nanosheets with activation energies of 44 ± 2 kJ/mol at edge sites and 58 ± 1 kJ/mol at external surface and internal and pore sites. Ethanol desorbs with activation energies of 58 ± 1 kJ/mol at internal pore sites and 66 ± 0.4 kJ/mol at external surface sites. Co-adsorption of water and ethanol was also investigated. The presence of ethanol was found to inhibit the desorption of water, resulting in a water desorption process with an activation energy of 68 ± 0.7 kJ/mol.

  5. Recombinant human B7.2 IgV-like domain expressed in bacteria maintains its co-stimulatory activity in vitro.

    Science.gov (United States)

    Yan, Xiaocai; Ma, Jun; Zheng, Jin; Lai, Baochang; Geng, Yiping; Wang, Yili; Si, Lüsheng

    2002-07-01

    To investigate which of the two immunoglobulin (Ig)-like domains, the immunoglobulin variable region homologous domain IgV (hB7.2 IgV) and the immunoglobulin constant region homologous domain IgC (hB7.2 IgC) on the human B7.2 molecule contains receptor binding sites, and to evaluate whether the B7.2 protein expressed in bacteria has biological activity in vitro. Three fragments of hB7.2 IgV,hB7.2 IgC and the complete extracellular region of human B7.2 containing both the IgV and IgC domains,hB7.2 Ig (V+C), were amplified by PCR and subcloned into pGEM-Teasy. Three recombinants,pGEX-4T-3-hB7.2 IgV,pGEX-4T-3-hB7.2 IgC and pGEX-4T-3-hB7.2 Ig (V+C), were generated by cloning the fragments into a prokaryote expression plasmid (pGEX-4T-3) and transformed into the host strain E. coli DH5alpha. The relevant target fusion proteins consisting of GST and hB7.2 IgV,hB7.2 IgC and hB7.2 Ig (V+C), were identified by SDS-PAGE and Western blotting. With the presence of the first signal imitated by anti-CD3 antibody, T cell activation was observed by exposing purified T lymphocytes to each soluble form of the three bacterially-produced human B7.2 fusion proteins by [(3)H]-TdR incorporation. Three recombinant fusion proteins of human B7.2, GST-hB7.2 IgV, GST-hB7.2 IgC and GST-hB7.2 Ig (V+C) were produced and detected in inclusion body form from engineered bacteria. With the first signal present,T lymphocytes proliferated when co-stimulated by bacterially-produced either GST-hB7.2 Ig (V+C) or GST-hB7.2 IgV fusion proteins, but not by GST-hB7.2 IgC. Functional human B7.2 fusion protein can be produced in bacteria. The IgV-like domain of human B7.2 is sufficient for B7.2 to interact with its counter-receptors and co-stimulate T lymphocytes.

  6. Induction of ovarian activity and ovulation in an induced ovulator, the maned wolf (Chrysocyon brachyurus), using GnRH agonist and recombinant LH.

    Science.gov (United States)

    Johnson, Amy E M; Freeman, Elizabeth W; Colgin, Mark; McDonough, Caitlin; Songsasen, Nucharin

    2014-07-01

    Assisted reproductive techniques, such as ovarian manipulation and artificial insemination, are useful for enhancing genetic management of threatened wildlife maintained ex situ. In this study, we used noninvasive fecal hormone monitoring to investigate (1) the influence of pairing with a male on endocrine responses of female maned wolves (Chrysocyon brachyurus) to a GnRH agonist (deslorelin) and (2) the efficiency of recombinant LH (reLH) on ovulation induction in females housed alone. Deslorelin (2.1 mg Ovuplant) was given to females that were either paired with a male (n = 4) or housed alone (n = 7); the implant was removed 7 to 11 days postimplantation. Three of seven singleton females were injected with reLH (0.0375 mg) on the day of implant removal, whereas the remaining females (n = 4) did not receive the additional treatment. Fecal samples were collected 5 to 7 days/wk from all females starting 11 days prior to hormone insertion until at least 70 days post implant removal for a total of 11 hormone treatment cycles. Fecal estrogen and progestagen metabolites were extracted and analyzed by enzyme immunoassay. Evidence of ovulation, demonstrated by a surge of estrogen followed by a significant rise in progestagen, occurred in all paired females. Three of the four singleton females that did not receive reLH treatment exhibited no rise in progestagen after an estrogen surge. All singleton females treated with reLH exhibited a rise in fecal progestagen after injection, indicating ovulation. In conclusion, deslorelin is effective at inducing ovarian activity and ovulation in paired female maned wolves; however, exogenous reLH is needed to induce ovulation in females housed alone. The findings obtained from this study serve as a foundation for future application of artificial insemination to enhance genetic management of this threatened species ex situ. Published by Elsevier Inc.

  7. Production and characterization of active recombinant interleukin-12/eGFP fusion protein in stably-transfected DF1 chicken cells.

    Science.gov (United States)

    Wu, Hsing Chieh; Chen, Yu San; Shen, Pin Chun; Shien, Jui Hung; Lee, Long Huw; Chiu, Hua Hsien

    2015-01-01

    The adjuvant activity of chicken interleukin-12 (chIL-12) protein has been described as similar to that of mammalian IL-12. Recombinant chIL-12 can be produced using several methods, but chIL-12 production in eukaryotic cells is lower than that in prokaryotic cells. Stimulating compounds, such as dimethyl sulfoxide (DMSO), can be added to animal cell cultures to overcome this drawback. In this study, we constructed a cell line, DF1/chIL-12 which stably expressed a fusion protein, chIL-12 and enhanced green fluorescent protein (eGFP) connected by a (G4 S)3 linker sequence. Fusion protein production was increased when cells were cultured in the presence of DMSO. When 1 × 10(6) DF1/chIL-12 cells were inoculated in a T-175 flask containing 30 mL of media, incubated for 15 h, and further cultivated in the presence of 4% DMSO for 48 h, the production of total fusion protein was mostly enhanced compared with the production of total fusion protein by using cell lysates induced with DMSO at other concentrations. The concentrations of the unpurified and purified total fusion proteins in cell lysates were 2,781 ± 2.72 ng mL(-1) and 2,207 ± 3.28 ng mL(-1) , respectively. The recovery rate was 79%. The fusion protein stimulated chicken splenocytes to produce IFN-γ, which was measured using an enzyme-linked immunosorbent assay, in the culture supernatant, indicating that treating DF1/chIL-12 cells with DMSO or producing chIL-12 in a fusion protein form does not have adverse effects on the bioactivity of chIL-12. © 2015 American Institute of Chemical Engineers.

  8. Expression, purification and characterization of the recombinant chimeric IgE Fc-fragment opossum-human-opossum (OSO), an active immunotherapeutic vaccine component.

    Science.gov (United States)

    Xu, Bingze; Lundgren, Mats; Magnusson, Ann-Christine; Fuentes, Alexis

    2010-11-01

    The active vaccine component recombinant chimeric IgE Fc-fragment opossum-human-opossum (OSO) has been expressed in CHO-K1 cells. It contains two identical polypeptide chains with 338 amino acid residues in each chain connected by two disulfide bridges. The cell lines were adapted to suspension culture in a serum-free medium. An expression level of 60 mg/L was obtained after 8 days in a shaking flask at a temperature of 31.5 degrees C. The OSO protein has been purified to homogeneity by a combination of three chromatographic steps. Virus inactivation and reduction by solvent detergent treatment and nano-filtration were included in the process. The residual host cell protein content was less than 50 ng/mg OSO as analyzed by ELISA. Purity was analyzed by SDS-PAGE under reducing and non-reducing conditions and was estimated by densitometry to be above 99.0%. The dimer content was less than 0.1% as estimated by analytical size exclusion chromatography. The molecular mass, as estimated by SDS-PAGE, is 90 kDa. A value of around 74 kDa was calculated from its amino acid composition. This indicates that the protein is heavily glycosylated containing around 18% carbohydrate. Isoelectric focusing in polyacrylamide gel disclosed a ladder type band pattern with pI values in the pH-range 7.0-8.3, indicating a variation in the sialic acid content. The OSO protein is not stable at temperatures above 40 degrees C and at pH values below 4 indicating that virus inactivation by incubating the protein solution at higher temperature or at lower pH is not possible. Copyright 2010 Elsevier Inc. All rights reserved.

  9. An infrared measurement of chemical desorption from interstellar ice analogues

    Science.gov (United States)

    Oba, Y.; Tomaru, T.; Lamberts, T.; Kouchi, A.; Watanabe, N.

    2018-03-01

    In molecular clouds at temperatures as low as 10 K, all species except hydrogen and helium should be locked in the heterogeneous ice on dust grain surfaces. Nevertheless, astronomical observations have detected over 150 different species in the gas phase in these clouds. The mechanism by which molecules are released from the dust surface below thermal desorption temperatures to be detectable in the gas phase is crucial for understanding the chemical evolution in such cold clouds. Chemical desorption, caused by the excess energy of an exothermic reaction, was first proposed as a key molecular release mechanism almost 50 years ago1. Chemical desorption can, in principle, take place at any temperature, even below the thermal desorption temperature. Therefore, astrochemical network models commonly include this process2,3. Although there have been a few previous experimental efforts4-6, no infrared measurement of the surface (which has a strong advantage to quantify chemical desorption) has been performed. Here, we report the first infrared in situ measurement of chemical desorption during the reactions H + H2S → HS + H2 (reaction 1) and HS + H → H2S (reaction 2), which are key to interstellar sulphur chemistry2,3. The present study clearly demonstrates that chemical desorption is a more efficient process for releasing H2S into the gas phase than was previously believed. The obtained effective cross-section for chemical desorption indicates that the chemical desorption rate exceeds the photodesorption rate in typical interstellar environments.

  10. Testosterone sorption and desorption: Effects of soil particle size

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Yong, E-mail: yqi01@unomaha.edu [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Zhang, Tian C. [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Ren, Yongzheng [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-08-30

    Graphical abstract: - Highlights: • Smaller soil particles have higher sorption and lower desorption rates. • The sorption capacity ranks as clay > silt > sand. • Small particles like clays have less potential for desorption. • Colloids (clays) have high potential to facilitate the transport of hormones in soil–water environments. - Abstract: Soils contain a wide range of particles of different diameters with different mobility during rainfall events. Effects of soil particles on sorption and desorption behaviors of steroid hormones have not been investigated. In this study, wet sieve washing and repeated sedimentation methods were used to fractionate the soils into five ranges. The sorption and desorption properties and related mechanisms of testosterone in batch reactors filled with fractionated soil particles were evaluated. Results of sorption and desorption kinetics indicate that small soil particles have higher sorption and lower desorption rates than that of big ones. Thermodynamic results show the sorption processes are spontaneous and exothermal. The sorption capacity ranks as clay > silt > sand, depending mainly on specific surface area and surface functional groups. The urea control test shows that hydrogen bonding contributes to testosterone sorption onto clay and silt but not on sand. Desorption tests indicate sorption is 36–65% irreversible from clay to sand. Clays have highest desorption hysteresis among these five soil fractions, indicating small particles like clays have less potential for desorption. The results provide indirect evidence on the colloid (clay)-facilitated transport of hormones (micro-pollutants) in soil environments.

  11. Anti-Bacterial Activity of Recombinant Human β-Defensin-3 Secreted in the Milk of Transgenic Goats Produced by Somatic Cell Nuclear Transfer

    Science.gov (United States)

    Han, Chengquan; Zhang, Hui; Wang, Yongsheng; Su, Jianmin; Quan, Fusheng; Gao, Mingqing; Zhang, Yong

    2013-01-01

    The present study was conducted to determine whether recombinant human β-defensin-3 (rHBD3) in the milk of transgenic goats has an anti-bacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Streptococcus agalactiae (S. agalactiae) that could cause mastitis. A HBD3 mammary-specific expression vector was transfected by electroporation into goat fetal fibroblasts which were used to produce fourteen healthy transgenic goats by somatic cell nuclear transfer. The expression level of rHBD3 in the milk of the six transgenic goats ranged from 98 to 121 µg/ml at 15 days of lactation, and was maintained at 90–111 µg/ml during the following 2 months. Milk samples from transgenic goats showed an obvious inhibitory activity against E. coli, S. aureus and S. agalactiae in vitro. The minimal inhibitory concentrations of rHBD3 in milk against E. coli, S. aureus and S. agalactiae were 9.5–10.5, 21.8–23.0 and 17.3–18.5 µg/mL, respectively, which was similar to those of the HBD3 standard (P>0.05). The in vivo anti-bacterial activities of rHBD3 in milk were examined by intramammary infusion of viable bacterial inoculums. We observed that 9/10 and 8/10 glands of non-transgenic goats infused with S. aureus and E. coli became infected. The mean numbers of viable bacteria went up to 2.9×103 and 95.4×103 CFU/ml at 48 h after infusion, respectively; the mean somatic cell counts (SCC) in infected glands reached up to 260.4×105 and 622.2×105 cells/ml, which were significantly higher than the SCC in uninfected goat glands. In contrast, no bacteria was presented in glands of transgenic goats and PBS-infused controls, and the SSC did not significantly change throughout the period. Moreover, the compositions and protein profiles of milk from transgenic and non-transgenic goats were identical. The present study demonstrated that HBD3 were an effective anti-bacterial protein to enhance the mastitis resistance of dairy animals. PMID:23799010

  12. Desorption of trihalomethanes in gas liquid contactors

    International Nuclear Information System (INIS)

    Ramirez Quesada, Kenneth

    2000-01-01

    Updated studies show that gastric cancer is related with the existence of trihalomethanes (THMs) in the drinking water. The trihalomethanes are sub products from the degradation of humic acids and your reaction with chlorine and bromine used like decontaminates. The desorption process is used to eliminate the THMs with air in contact with the water. The experimental design was used in three contactors. The contactors selected were: the bubbling's column, the packed column and the shaken tank without screen. There were selected three variable: initial concentration of THMs, the residence time and the turbulence degree (measured with the Reynolds number). The concentrations were made with a gas chromatograph. The objective of this project is to do a comparison with the gas liquid contactors more used in the industrial level to determinate which ones are the best in the desorption process. The conclusion of the experimental design is that the tank is the equipment with the best capacity to eliminate THMs. Too it includes other techniques to eliminate THMs of the water and your treatment [es

  13. Desorption isotherms and isosteric heat of 'cajuzinho-do-cerrado' achenes

    Directory of Open Access Journals (Sweden)

    Karine F. Barbosa

    2016-05-01

    Full Text Available ABSTRACT The objective of this study was to determine the desorption isotherms of 'cajuzinho-do-cerrado' achenes (Anacardium humile St. Hil. in various conditions of temperature and water activity, as well as to select the one that best represents the phenomenon and to determine the isosteric heat of desorption. The fruits were collected at the Emas National Park, in the municipality of Mineiros-GO, Brazil, pulped and then subjected to drying in silica gel at temperature of 25 ± 2 °C until the moisture contents of 17.6, 13.6, 11.1, 8.7 and 5.3 (d.b.%. After drying, the desorption isotherms were determined by the indirect static method. The water activity (Aw was determined at different temperatures, and the achenes were placed in a B.O.D. chamber, regulated at 10, 20, 30 and 40 °C. Data of hygroscopic equilibrium moisture content were fitted to different mathematical models through non-linear regression analysis, using the Gauss-Newton method. The Copace model was the one that best represented the hygroscopicity of 'cajuzinho-do-cerrado' achenes, while the integral isosteric heat of desorption of 'cajuzinho-do-cerrado' achenes for the moisture content range of 4.51 to 13.40 (% d.b. varied from 2,734.82 to 2,548.49 kJ kg-1.

  14. Characterization of foot- and mouth disease virus antigen by surface-enhanced laser desorption ionization-time of flight-mass spectrometry in aqueous and oil-emulsion formulations

    NARCIS (Netherlands)

    Harmsen, M.M.; Jansen, J.; Westra, D.F.; Coco-Martin, J.M.

    2010-01-01

    We have used a novel method, surface-enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS), to characterize foot-and-mouth disease virus (FMDV) vaccine antigens. Using specific capture with FMDV binding recombinant antibody fragments and tryptic digestion of FMDV

  15. Hadron correlations from recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)

    2005-01-01

    Quark recombination is a successful model to describe the hadronization of a deconfined quark gluon plasma. Jet-like dihadron correlations measured at RHIC provide a challenge for this picture. We discuss how correlations between hadrons can arise from correlations between partons before hadronization. An enhancement of correlations through the recombination process, similar to the enhancement of elliptic flow is found. Hot spots from completely or partially quenched jets are a likely source of such parton correlations.

  16. A novel lipid transfer protein from the pea Pisum sativum: isolation, recombinant expression, solution structure, antifungal activity, lipid binding, and allergenic properties.

    Science.gov (United States)

    Bogdanov, Ivan V; Shenkarev, Zakhar O; Finkina, Ekaterina I; Melnikova, Daria N; Rumynskiy, Eugene I; Arseniev, Alexander S; Ovchinnikova, Tatiana V

    2016-04-30

    Plant lipid transfer proteins (LTPs) assemble a family of small (7-9 kDa) ubiquitous cationic proteins with an ability to bind and transport lipids as well as participate in various physiological processes including defense against phytopathogens. They also form one of the most clinically relevant classes of plant allergens. Nothing is known to date about correlation between lipid-binding and IgE-binding properties of LTPs. The garden pea Pisum sativum is widely consumed crop and important allergenic specie of the legume family. This work is aimed at isolation of a novel LTP from pea seeds and characterization of its structural, functional, and allergenic properties. Three novel lipid transfer proteins, designated as Ps-LTP1-3, were found in the garden pea Pisum sativum, their cDNA sequences were determined, and mRNA expression levels of all the three proteins were measured at different pea organs. Ps-LTP1 was isolated for the first time from the pea seeds, and its complete amino acid sequence was determined. The protein exhibits antifungal activity and is a membrane-active compound that causes a leakage from artificial liposomes. The protein binds various lipids including bioactive jasmonic acid. Spatial structure of the recombinant uniformly (13)C,(15)N-labelled Ps-LTP1 was solved by heteronuclear NMR spectroscopy. In solution the unliganded protein represents the mixture of two conformers (relative populations ~ 85:15) which are interconnected by exchange process with characteristic time ~ 100 ms. Hydrophobic residues of major conformer form a relatively large internal tunnel-like lipid-binding cavity (van der Waals volume comes up to ~1000 Å(3)). The minor conformer probably corresponds to the protein with the partially collapsed internal cavity. For the first time conformational heterogeneity in solution was shown for an unliganded plant lipid transfer protein. Heat denaturation profile and simulated gastrointestinal digestion assay showed that Ps

  17. Association of serial biochemical markers with acute ischemic stroke: the National Institute of Neurological Disorders and Stroke recombinant tissue plasminogen activator Stroke Study.

    Science.gov (United States)

    Jauch, Edward C; Lindsell, Christopher; Broderick, Joseph; Fagan, Susan C; Tilley, Barbara C; Levine, Steven R

    2006-10-01

    Biochemical markers of acute neuronal injury may aid in the diagnosis and management of acute ischemic stroke. Serum samples from the National Institute for Neurological Disorders and Stroke (NINDS) recombinant tissue plasminogen activator Stroke Study were analyzed for the presence of 4 biochemical markers of neuronal, glial, and endothelial cell injury. These biochemical markers, myelin basic protein (MBP), neuron-specific enolase (NSE), S100beta, and soluble thrombomodulin, were studied for an association with initial stroke severity, infarct volume, and functional outcome. In the original NINDS study, serum samples were drawn from all patients on presentation to the Emergency Department and at approximately 2 and 24 hours after initiation of study therapy. In this analysis, stored serum samples were available for 359 patients; 107 patients had samples for all 3 time points. Serum marker concentrations were measured by ELISA techniques. We examined the relation between serum concentrations of each marker and the degree of baseline neurological deficit, functional outcome, and infarct size on computed tomography at 24 hours and the effect of fibrinolytic therapy. Higher 24-hour peak concentrations of MBP, NSE, and S100beta were associated with higher National Institutes of Health Stroke Scale baseline scores (r=0.186, P<0.0001; r=0.117, P=0.032; and r=0.263, P<0.0001, respectively). Higher peak concentrations of MBP and S100beta (r=0.209, P<0.0001; r=0.239, P<0.0001) were associated with larger computed tomography lesion volumes. Patients with favorable outcomes had smaller changes in MBP and S100beta (P<0.05) concentrations in the first 24 hours. Soluble thrombomodulin was not associated with any severity or outcome measure. This study corroborates previous work demonstrating correlations of MBP, NSE, and S100beta with clinical and radiographic features in acute stroke. Despite significantly better outcomes in the tissue plasminogen activator-treated group, we

  18. Improved antifungal activity of barley derived chitinase I gene that overexpress a 32 kDa recombinant chitinase in Escherichia coli host

    Directory of Open Access Journals (Sweden)

    Nida Toufiq

    Full Text Available Abstract Agricultural crops suffer many diseases, including fungal and bacterial infections, causing significant yield losses. The identification and characterisation of pathogenesis-related protein genes, such as chitinases, can lead to reduction in pathogen growth, thereby increasing tolerance against fungal pathogens. In the present study, the chitinase I gene was isolated from the genomic DNA of Barley (Hordeum vulgare L. cultivar, Haider-93. The isolated DNA was used as template for the amplification of the ∼935 bp full-length chitinase I gene. Based on the sequence of the amplified gene fragment, class I barley chitinase shares 93% amino acid sequence homology with class II wheat chitinase. Interestingly, barley class I chitinase and class II chitinase do not share sequence homology. Furthermore, the amplified fragment was expressed in Escherichia coli Rosetta strain under the control of T7 promoter in pET 30a vector. Recombinant chitinase protein of 35 kDa exhibited highest expression at 0.5 mM concentration of IPTG. Expressed recombinant protein of 35 kDa was purified to homogeneity with affinity chromatography. Following purification, a Western blot assay for recombinant chitinase protein measuring 35 kDa was developed with His-tag specific antibodies. The purified recombinant chitinase protein was demonstrated to inhibit significantly the important phytopathogenic fungi Alternaria solani, Fusarium spp, Rhizoctonia solani and Verticillium dahliae compared to the control at concentrations of 80 µg and 200 µg.

  19. Dissociation of recombinant prion autocatalysis from infectivity.

    Science.gov (United States)

    Noble, Geoffrey P; Supattapone, Surachai

    2015-01-01

    Within the mammalian prion field, the existence of recombinant prion protein (PrP) conformers with self-replicating (ie. autocatalytic) activity in vitro but little to no infectious activity in vivo challenges a key prediction of the protein-only hypothesis of prion replication--that autocatalytic PrP conformers should be infectious. To understand this dissociation of autocatalysis from infectivity, we recently performed a structural and functional comparison between a highly infectious and non-infectious pair of autocatalytic recombinant PrP conformers derived from the same initial prion strain. (1) We identified restricted, C-terminal structural differences between these 2 conformers and provided evidence that these relatively subtle differences prevent the non-infectious conformer from templating the conversion of native PrP(C) substrates containing a glycosylphosphatidylinositol (GPI) anchor. (1) In this article we discuss a model, consistent with these findings, in which recombinant PrP, lacking post-translational modifications and associated folding constraints, is capable of adopting a wide variety of autocatalytic conformations. Only a subset of these recombinant conformers can be adopted by post-translationally modified native PrP(C), and this subset represents the recombinant conformers with high specific infectivity. We examine this model's implications for the generation of highly infectious recombinant prions and the protein-only hypothesis of prion replication.

  20. Workshop on Radio Recombination Lines

    CERN Document Server

    1980-01-01

    Since their first detection 15 years ago, radio recombination lines from several elements have been observed in a wide variety of objects including HII regions, planetary nebulae, molecular clouds, the diffuse interstellar medium, and recently, other galaxies. The observations span almost the entire range from 0.1 to 100 GHz, and employ both single­ djsh and aperture synthesis techniques. The theory of radio recombination lines has also advanced strongly, to the point where it is perhaps one of the best-understood in astro­ physics. In a parallel development, it has become possible over the last decade to study these same highly-excited atoms in the laboratory; this work provides further confirmation of the theoretical framework. However there has been continuing controversy over the astrophysical interpre­ tation of radio recombination line observations, especially regarding the role of stimulated emission. A workshop was held in Ottawa on 24-25 August, 1979, bringing together many of the active scientist...

  1. Damage, trapping and desorption at the implantation of helium and deuterium in graphite, diamond and silicon carbide

    International Nuclear Information System (INIS)

    Lopez, G.A.R.

    1995-07-01

    The production, thermal stability and structure of ion induced defects have been studied by Rutherford backscattering in channeling geometry for the implantation of helium and deuterium in graphite, diamond and silicon carbide with energies of 8 and 20 keV. At the implantation of deuterium and helium ions more defects were measured in graphite than in diamond or silicon carbide at equal experimental conditions. This is due to increased backscattering in graphite, which is caused by the splitting and tilting of crystallites and a local reordering of lattice atoms around defects. At 300 K, Helium produces more defects in all three materials than deuterium with equal depth distribution of defects. The ratio of the defects produced by helium and deuterium agrees very well with the corresponding ratio of the energy deposited in nuclear collisions. In graphite, only small concentrations of deuterium induced defects anneal below 800 K, while in diamond small concentrations of deuterium as well as of helium induced defects anneal mostly below 800 K. This annealing behavior is considered to be due to recombination of point defects. The buildup of helium and deuterium in graphite is different. The trapping of deuterium proceeds until saturation is reached, while in the case of helium trapping is interrupted by flaking. In diamond, deuterium as well as helium are trapped almost completely until at higher fluences reemission starts and saturation is reached. Two desorption mechanisms were identified for the thermal desorption of helium from base-oriented graphite. Helium implanted at low fluences desorbs diffusing to the surface, while for the implantation of high fluences the release of helium due to blistering dominates. The desorption of deuterium from graphite and diamond shows differences. While in graphite the desorption starts already at 800 K, in diamond up to 1140 K only little desorption can be observed. These differences can be explained by the different transport

  2. High-Mannose Specific Lectin and Its Recombinants from a Carrageenophyta Kappaphycus alvarezii Represent a Potent Anti-HIV Activity Through High-Affinity Binding to the Viral Envelope Glycoprotein gp120.

    Science.gov (United States)

    Hirayama, Makoto; Shibata, Hiromi; Imamura, Koji; Sakaguchi, Takemasa; Hori, Kanji

    2016-02-01

    We previously reported that a high-mannose binding lectin KAA-2 from the red alga Kappaphycus alvarezii, which is an economically important species and widely cultivated as a source of carrageenans, had a potent anti-influenza virus activity. In this study, the full-length sequences of two KAA isoforms, KAA-1 and KAA-2, were elucidated by a combination of peptide mapping and complementary DNA (cDNA) cloning. They consisted of four internal tandem-repeated domains, which are conserved in high-mannose specific lectins from lower organisms, including a cyanobacterium Oscillatoria agardhii and a red alga Eucheuma serra. Using an Escherichia coli expression system, an active recombinant form of KAA-1 (His-tagged rKAA-1) was successfully generated in the yield of 115 mg per liter of culture. In a detailed oligosaccharide binding analysis by a centrifugal ultrafiltration-HPLC method with 27 pyridylaminated oligosaccharides, His-tagged rKAA-1 and rKAA-1 specifically bound to high-mannose N-glycans with an exposed α1-3 mannose in the D2 arm as the native lectin did. Predicted from oligosaccharide binding specificity, a surface plasmon resonance analysis revealed that the recombinants exhibit strong interaction with gp120, a heavily glycosylated envelope glycoprotein of HIV with high association constants (1.48 - 1.61 × 10(9) M(-1)). Native KAAs and the recombinants inhibited the HIV-1 entry at IC50s of low nanomolar levels (7.3-12.9 nM). Thus, the recombinant proteins would be useful as antiviral reagents targeting the viral surface glycoproteins with high-mannose N-glycans, and the cultivated alga K. alvarezii could also be a good source of not only carrageenans but also this functional lectin(s).

  3. Uso de fator VII recombinante ativado para tratamento e profilaxia de grandes sangramentos Use of recombinant activated factor VII for treatment and prophylaxis of major bleeding

    Directory of Open Access Journals (Sweden)

    Flávio Augusto Henriques Vince

    2009-09-01

    pacientes. Dessa forma, o recente aumento do uso de rFVIIa em situações ainda não aprovadas levou ao crescente questionamento sobre eficácia e segurança desta específica medicação em tais situações.INTRODUCTION: Recombinant activated factor VII (rFVIIa is a protein produced by genetic engineering, the structure is very similar to the structure of intrinsic activated factor VII (FVII. Its action is based on knowledge of the coagulation mechanism in vivo by acting in direct activation of factor X independent resulting in formation of thrombin at the injury site and thereby contributing to the formation of stable fibrin clots without the action of factor VIII and factor IX. METHODS: Was conducted extensive review of the literature in order to determine the new findings related to the use of recombinant activated factor VII in patients with severe bleeding. RESULTS: It was found that the use of rFVIIa started in the 80's for prophylaxis and treatment of bleeding in patients with a history of hemophilia A or B with inhibitors to factor VIII and IX, factor VII deficiency and Glanzmann's thrombasthenia refractory to replacement platelet. In 1999 its use was expanded to other clinical situations and thus began to be published several studies showing the efficacy of rFVIIa as a pro-hemostatic agent in patients with bleeding disorders or other previously healthy patients with a history of acute bleeding of major consequence. Trauma is the leading cause of mortality worldwide and uncontrolled bleeding the main challenge in caring for these patients. It is common for the association of trauma with coagulopathy, requiring in some cases specific therapy to treat it. At this point in adjuvant therapy with rFVIIa should be considered. Other common causes of bleeding are the heart, gynecologic/obstetric surgeries and diseases involving the liver. The coagulopathy in these cases is deficiency of factors dependent on vitamin K, and the FVII factor with smaller half life. CONCLUSION

  4. Modeling Organic Contaminant Desorption from Municipal Solid Waste Components

    Science.gov (United States)

    Knappe, D. R.; Wu, B.; Barlaz, M. A.

    2002-12-01

    Approximately 25% of the sites on the National Priority List (NPL) of Superfund are municipal landfills that accepted hazardous waste. Unlined landfills typically result in groundwater contamination, and priority pollutants such as alkylbenzenes are often present. To select cost-effective risk management alternatives, better information on factors controlling the fate of hydrophobic organic contaminants (HOCs) in landfills is required. The objectives of this study were (1) to investigate the effects of HOC aging time, anaerobic sorbent decomposition, and leachate composition on HOC desorption rates, and (2) to simulate HOC desorption rates from polymers and biopolymer composites with suitable diffusion models. Experiments were conducted with individual components of municipal solid waste (MSW) including polyvinyl chloride (PVC), high-density polyethylene (HDPE), newsprint, office paper, and model food and yard waste (rabbit food). Each of the biopolymer composites (office paper, newsprint, rabbit food) was tested in both fresh and anaerobically decomposed form. To determine the effects of aging on alkylbenzene desorption rates, batch desorption tests were performed after sorbents were exposed to toluene for 30 and 250 days in flame-sealed ampules. Desorption tests showed that alkylbenzene desorption rates varied greatly among MSW components (PVC slowest, fresh rabbit food and newsprint fastest). Furthermore, desorption rates decreased as aging time increased. A single-parameter polymer diffusion model successfully described PVC and HDPE desorption data, but it failed to simulate desorption rate data for biopolymer composites. For biopolymer composites, a three-parameter biphasic polymer diffusion model was employed, which successfully simulated both the initial rapid and the subsequent slow desorption of toluene. Toluene desorption rates from MSW mixtures were predicted for typical MSW compositions in the years 1960 and 1997. For the older MSW mixture, which had a

  5. Evaluation of adjuvant activity of fractions derived from Agaricus blazei, when in association with the recombinant LiHyp1 protein, to protect against visceral leishmaniasis.

    Science.gov (United States)

    de Jesus Pereira, Nathália Cristina; Régis, Wiliam César Bento; Costa, Lourena Emanuele; de Oliveira, Jamil Silvano; da Silva, Alanna Gomes; Martins, Vivian Tamietti; Duarte, Mariana Costa; de Souza, José Roberto Rodrigues; Lage, Paula Sousa; Schneider, Mônica Santos; Melo, Maria Norma; Soto, Manuel; Soares, Sandra Aguiar; Tavares, Carlos Alberto Pereira; Chávez-Fumagalli, Miguel Angel; Coelho, Eduardo Antonio Ferraz

    2015-06-01

    The development of effective prophylactic strategies to prevent leishmaniasis has become a high priority. No less important than the choice of an antigen, the association of an appropriate adjuvant is necessary to achieve a successful vaccination, as the majority of the tested antigens contain limited immunogenic properties, and need to be supplemented with immune response adjuvants in order to boost their immunogenicity. However, few effective adjuvants that can be used against leishmaniasis exist on the market today; therefore, it is possible to speculate that the research aiming to identify new adjuvants could be considered relevant. Recently, Agaricus blazei extracts have proved to be useful in enhancing the immune response to DNA vaccines against some diseases. This was based on the Th1 adjuvant activity of the polysaccharide-rich fractions from this mushroom. In this context, the present study evaluated purified fractions derived from Agaricus blazei as Th1 adjuvants through in vitro assays of their immune stimulation of spleen cells derived from naive BALB/c mice. Two of the tested six fractions (namely F2 and F4) were characterized as polysaccharide-rich fractions, and were able to induce high levels of IFN-γ, and low levels of IL-4 and IL-10 in the spleen cells. The efficacy of adjuvant action against L. infantum was evaluated in BALB/c mice, with these fractions being administered together with a recombinant antigen, LiHyp1, which was previously evaluated as a vaccine candidate, associated with saponin, against visceral leishmaniasis (VL). The associations between LiHyp1/F2 and LiHyp1/F4 were able to induce an in vivo Th1 response, which was primed by high levels of IFN-γ, IL-12, and GM-CSF, by low levels of IL-4 and IL-10; as well as by a predominance of IgG2a antibodies in the vaccinated animals. After infection, the immune profile was maintained, and the vaccines proved to be effective against L. infantum. The immune stimulatory effects in the

  6. Effects of edaravone, the free radical scavenger, on outcomes in acute cerebral infarction patients treated with ultra-early thrombolysis of recombinant tissue plasminogen activator.

    Science.gov (United States)

    Lee, Xian-Ru; Xiang, Gui-Ling

    2018-04-01

    Edaravone, a free radical scavenger, alleviates blood-brain barrier disruption in conjunction with suppression of the inflammatory reaction in acute cerebral infarction. Thrombolysis with recombinant tissue plasminogen activator (rtPA) is an established therapy for acute cerebral infarction patients. The purpose of this study was to assess the effects of edaravone on outcomes in acute cerebral infarction patients treated with ultra-early thrombolysis of iv-rt-PA. We conducted a retrospective cohort study using the database of Ningbo First Hospital. We identified patients who were admitted with a primary diagnosis of acute cerebral infarction and treated with intravenous rtPA(iv-rtPA) within 3 h of symptom onset from March 1st in 2014 to October 31st in 2016.Thenceforth,the patients were divided into 2 groups by treatment with(edaravone group) or without edaravone(non-edaravone group). Glasgow Coma Scale (GCS) scores and mRS score at admission were used. Clinical background, risk factors for acute cerebral infarction hemorrhagic transformation, 7-day mortality, recanalization rate, bleeding complications and blood rheology indexes were collected. We also collected the following factors: National Institutes of Health Stroke Scale scores, barthel index. 136 patients treated without edaravone during hospitalization were selected in non-edaravone group while edaravone group included 132 patients treated with edaravone during hospitalization. The patient baseline distributions were well balanced between non-edaravone group and edaravone group. The rate of hemorrhagic transformation in non-edaravone group was higher than that in edaravone group (P < 0.05). The NIHSS scores 7 days and 14 days after symptom onset were higher in non-edaravone group than in edaravone group (both P < 0.05). Edaravone group showed a higher recanalization rate and a lower bleeding complications rate at discharge than the non-edaravone group (both P < 0.05). The differences of

  7. Sex-based differences in response to recombinant tissue plasminogen activator in acute ischemic stroke: a pooled analysis of randomized clinical trials.

    Science.gov (United States)

    Kent, David M; Price, Lori Lyn; Ringleb, Peter; Hill, Michael D; Selker, Harry P

    2005-01-01

    Women experience worse outcomes after stroke compared with men. Prior work has suggested sex-based differences in coagulation and fibrinolysis markers in subjects with acute stroke. We explored whether sex might modify the effect of recombinant tissue plasminogen activator (rtPA) on outcomes in patients with acute ischemic stroke. Using a combined database including subjects from the National Institute of Neurological Disorders and Stroke (NINDS), Alteplase Thrombolysis for Acute Noninterventional Therapy in Ischemic Stroke (ATLANTIS) A and B, and the Second European Cooperative Acute Stroke Study (ECASS II) trials, we examined 90-day outcomes in patients randomized to rtPA versus placebo by sex. We used logistic regression to control for potential confounders. Among 988 women treated between 0 and 6 hours from symptom onset, patients receiving rtPA were significantly more likely than those receiving placebo to have a modified Rankin Score < or =1 (40.5% versus 30.3%, P<0.0008). Among 1190 men, the trend toward benefit in the overall group did not reach statistical significance (38.5% versus 36.7%, P=0.52). An unadjusted analysis showed that women were significantly more likely to benefit from rtPA compared with men (P=0.04). Controlling for age, baseline National Institutes of Health Stroke Scale, diabetes, symptom onset to treatment time, prior stroke, systolic blood pressure, extent of hypoattenuation on baseline computed tomography scan and several significant interaction terms (including onset to treatment time-by-treatment and systolic blood pressure-by treatment) did not substantially change the strength of the interaction between gender and rtPA treatment (P=0.04). In this pooled analysis of rtPA in acute ischemic stroke, women benefited more than men, and the usual gender difference in outcome favoring men was not observed in the thrombolytic therapy group. For patients presenting at later time intervals, when the risks and benefits of rtPA are more finely

  8. Recombinant Activated Factor VIIa (rFVIIa) Treatment in Very-Low-Birth-Weight (VLBW) Premature Infants with Acute Pulmonary Hemorrhage: A Single-Center, Retrospective Study.

    Science.gov (United States)

    Cosar, Hese; Isik, Halil; Cakır, Salih Cagrı; Yar, Nese; Goksen, Bulent; Tokbay, Hakan; Kertmen, Hasan; Erdoğan, Nihal; Durak, Ikbal

    2017-02-01

    We aimed to evaluate the efficacy of intravenous administration of recombinant activated factor VIIa (rFVIIa) for acute pulmonary hemorrhage treatment in very-low-birth-weight (VLBW) premature infants. This study was carried out retrospectively in premature infants with pulmonary hemorrhage that were ≤30 weeks gestational age or hemorrhage who were hospitalized in our neonatal intensive care unit between 01 January 2013 and 31 December 2015 were evaluated. Group 1 (n = 21) received rFVIIa support within the first 30 min of pulmonary hemorrhage plus conventional treatment, while Group 2 (n = 21) received conventional treatment only. The number of patients whose pulmonary hemorrhage was stopped within the first 2 h was significantly higher in Group 1 than Group 2 (n = 14 vs n = 4; p = 0.002). After pulmonary hemorrhage, hemoglobin values of Group 1 were higher than Group 2 (11.12 ± 1.06 vs 10.14 ± 1.59 g/dL; p = 0.024). Erythrocyte suspension (1.43 ± 4.51 vs 5.71 ± 7.46 mL/kg; p = 0.030) and fresh frozen plasma use (5.71 ± 8.10 vs 19.52 ± 12.44 mL/kg; p hemorrhage after 72 h, overall mortality, mortality from pulmonary hemorrhage, surfactant use, intubation time, hospitalization duration, intraventricular hemorrhage (IVH), severe IVH, patent ductus arteriosus rates, or short-term complication rates. rFVIIa administration was observed to be effective in stopping pulmonary hemorrhage, reducing blood product requirement, and improving coagulation test parameters. Prospective studies are needed to evaluate the efficacy, reliability, and long-term results of rFVIIa in the prevention and treatment of pulmonary hemorrhage in premature infants.

  9. Copper desorption from Gelidium algal biomass.

    Science.gov (United States)

    Vilar, Vítor J P; Botelho, Cidália M S; Boaventura, Rui A R

    2007-04-01

    Desorption of divalent copper from marine algae Gelidium sesquipedale, an algal waste (from agar extraction industry) and a composite material (the algal waste immobilized in polyacrylonitrile) was studied in a batch system. Copper ions were first adsorbed until saturation and then desorbed by HNO(3) and Na(2)EDTA solutions. Elution efficiency using HNO(3) increases as pH decreases. At pH=1, for a solid to liquid ratio S/L=4gl(-1), elution efficiency was 97%, 95% and 88%, the stoichiometric coefficient for the ionic exchange, 0.70+/-0.02, 0.73+/-0.05 and 0.76+/-0.06 and the selectivity coefficient, 0.93+/-0.07, 1.0+/-0.3 and 1.1+/-0.3, respectively, for algae Gelidium, algal waste and composite material. Complexation of copper ions by EDTA occurs in a molar proportion of 1:1 and the elution efficiency increases with EDTA concentration. For concentrations of 1.4, 0.88 and 0.57 mmoll(-1), the elution efficiency for S/L=4gl(-1), was 91%, 86% and 78%, respectively, for algae Gelidium, algal waste and composite material. The S/L ratio, in the range 1-20gl(-1), has little influence on copper recovery by using 0.1M HNO(3). Desorption kinetics was very fast for all biosorbents. Kinetic data using HNO(3) as eluant were well described by the mass transfer model, considering the average metal concentration in the solid phase and the equilibrium relationship given by the mass action law. The homogeneous diffusion coefficient varied between 1.0 x 10(-7)cm(2)s(-1) for algae Gelidium and 3.0 x 10(-7)cm(2)s(-1) for the composite material.

  10. Study of the radium sorption/desorption on goethite

    International Nuclear Information System (INIS)

    Bassot, S.; Stammose, D.; Mallet, C.; Lefebvre, C.; Ferreux, J.-M.

    2000-01-01

    The oxi-hydroxides, present at trace level in uranium mill tailings, are responsible of about 70% of the 226 radium sorption, half being fixed on crystallized forms. This radionuclide (half time=1622y), present at high level (50 to 100kBq.kg -1 ), can be released in groundwater, involving a possible contamination of the food chain (actual concentration limit=0.37Bq.1 -1 ). So, it is very important to point out the mechanisms of the radium sorption/desorption on crystallized oxi-hydroxides as a function of chemical conditions of the system. The radium sorption on synthetic goethite α-FeOOH has been studied as a function of contact time, initial radium activity, pH, sodium and calcium concentrations. The results show that, after one hour of contact time (necessary to reach equilibrium), the radium sorption increases widely in a pH range 6-7. The increase of Na + concentration is without influence on the radium sorption, indicating the low interactions between sodium and surface sites. At the opposite, the presence of calcium in solution decreases widely the radium sorption, that indicates a competition between calcium and radium for the same kind of sorption sites of the oxi-hydroxide surface. The percentage of radium desorbed increases widely with time, from 1 to 120h and becomes constant at a time higher than 120h. This long equilibrium time for desorption in comparison with sorption one can be explain by a local evolution of the sorption sites of the solid, which become less accessible for the solution in contact. (author)

  11. Regulation of Meiotic Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Gregory p. Copenhaver

    2011-11-09

    Meiotic recombination results in the heritable rearrangement of DNA, primarily through reciprocal exchange between homologous chromosome or gene conversion. In plants these events are critical for ensuring proper chromosome segregation, facilitating DNA repair and providing a basis for genetic diversity. Understanding this fundamental biological mechanism will directly facilitate trait mapping, conventional plant breeding, and development of genetic engineering techniques that will help support the responsible production and conversion of renewable resources for fuels, chemicals, and the conservation of energy (1-3). Substantial progress has been made in understanding the basal recombination machinery, much of which is conserved in organisms as diverse as yeast, plants and mammals (4, 5). Significantly less is known about the factors that regulate how often and where that basal machinery acts on higher eukaryotic chromosomes. One important mechanism for regulating the frequency and distribution of meiotic recombination is crossover interference - or the ability of one recombination event to influence nearby events. The MUS81 gene is thought to play an important role in regulating the influence of interference on crossing over. The immediate goals of this project are to use reverse genetics to identify mutants in two putative MUS81 homologs in the model plant Arabidopsis thaliana, characterize those mutants and initiate a novel forward genetic screen for additional regulators of meiotic recombination. The long-term goal of the project is to understand how meiotic recombination is regulated in higher eukaryotes with an emphasis on the molecular basis of crossover interference. The ability to monitor recombination in all four meiotic products (tetrad analysis) has been a powerful tool in the arsenal of yeast geneticists. Previously, the qrt mutant of Arabidopsis, which causes the four pollen products of male meiosis to remain attached, was developed as a facile system

  12. Regulation of homologous recombination at telomeres in budding yeast

    DEFF Research Database (Denmark)

    Eckert-Boulet, Nadine; Lisby, Michael

    2010-01-01

    Homologous recombination is suppressed at normal length telomere sequences. In contrast, telomere recombination is allowed when telomeres erode in the absence of telomerase activity or as a consequence of nucleolytic degradation or incomplete replication. Here, we review the mechanisms that contr...... that contribute to regulating mitotic homologous recombination at telomeres and the role of these mechanisms in signalling short telomeres in the budding yeast Saccharomyces cerevisiae....

  13. In vitro V(D)J recombination: Signal joint formation

    OpenAIRE

    Cortes, Patricia; Weis-Garcia, Frances; Misulovin, Ziva; Nussenzweig, Andre; Lai, Jiann-Shiun; Li, Gloria; Nussenzweig, Michel C.; Baltimore, David

    1996-01-01

    The first step of V(D)J recombination, specific cleavage at the recombination signal sequence (RSS), can be carried out by the recombination activating proteins RAG1 and RAG2. In vivo, the cleaved coding and signal ends must be rejoined to generate functional antigen receptors and maintain chromosomal integrity. We have investigated signal joint formation using deletion and inversion substrates in a cell free system. RAG1 and RAG2 alone or in combination were unabl...

  14. Adlayer structure dependent ultrafast desorption dynamics in carbon monoxide adsorbed on Pd (111)

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Sung-Young; Camillone, Nina R.; Camillone, Nicholas, E-mail: nicholas@bnl.gov [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Xu, Pan [Department of Chemistry, Stony Brook University, Stony Brook, New York 11794 (United States); White, Michael G. [Chemistry Department, Brookhaven National Laboratory, Upton, New York 11973 (United States); Department of Chemistry, Stony Brook University, Stony Brook, New York 11794 (United States)

    2016-07-07

    We report our ultrafast photoinduced desorption investigation of the coverage dependence of substrate–adsorbate energy transfer in carbon monoxide adlayers on the (111) surface of palladium. As the CO coverage is increased, the adsorption site population shifts from all threefold hollows (up to 0.33 ML), to bridge and near bridge (>0.5 to 0.6 ML) and finally to mixed threefold hollow plus top site (at saturation at 0.75 ML). We show that between 0.24 and 0.75 ML this progression of binding site motifs is accompanied by two remarkable features in the ultrafast photoinduced desorption of the adsorbates: (i) the desorption probability increases roughly two orders magnitude, and (ii) the adsorbate–substrate energy transfer rate observed in two-pulse correlation experiments varies nonmonotonically, having a minimum at intermediate coverages. Simulations using a phenomenological model to describe the adsorbate–substrate energy transfer in terms of frictional coupling indicate that these features are consistent with an adsorption-site dependent electron-mediated energy coupling strength, η{sub el}, that decreases with binding site in the order: three-fold hollow > bridge and near bridge > top site. This weakening of η{sub el} largely counterbalances the decrease in the desorption activation energy that accompanies this progression of adsorption site motifs, moderating what would otherwise be a rise of several orders of magnitude in the desorption probability. Within this framework, the observed energy transfer rate enhancement at saturation coverage is due to interadsorbate energy transfer from the copopulation of molecules bound in three-fold hollows to their top-site neighbors.

  15. Recombination of chlorine atoms on plasma-conditioned stainless steel surfaces in the presence of adsorbed Cl{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Stafford, Luc; Poirier, Jean-Sebastien; Margot, Joelle [Departement de Physique, Universite de Montreal, Montreal, Quebec, H3C 3J7 (Canada); Khare, Rohit; Guha, Joydeep; Donnelly, Vincent M, E-mail: luc.stafford@umontreal.c, E-mail: vmdonnelly@uh.ed [Department of Chemical and Biomolecular Engineering, University of Houston, Houston, TX 77204 (United States)

    2009-03-07

    We investigated the interactions of atomic and molecular chlorine with plasma-conditioned stainless steel surfaces through both experiments and modelling. The recombination of Cl during adsorption and desorption of Cl{sub 2} was characterized using a rotating-substrate technique in which portions of the cylindrical substrate surface are periodically exposed to an inductively coupled chlorine plasma and then to an Auger electron spectrometer in separate, differentially pumped chambers. After several hours of exposure to the Cl{sub 2} plasma, the stainless steel substrate became coated with a Si-oxychloride-based layer (Fe : Si : O : Cl {approx} 1 : 13 : 13 : 3) due to chlorine adsorption and the erosion of the silica discharge tube. Desorption of Cl{sub 2} from this surface was monitored through measurements of pressure rises in the Auger chamber as a function of substrate rotation frequency. Significant adsorption and desorption of Cl{sub 2} was observed with the plasma off, similar to that observed previously on plasma-conditioned anodized aluminium surfaces, but with much faster desorption rates that are most likely attributable to the smoother and non-porous stainless steel surface morphology. When the plasma was turned on, a much larger pressure rise was observed due to Langmuir-Hinshelwood recombination of Cl atoms. Recombination coefficients, {gamma}{sub Cl}, ranged from 0.004 to 0.03 and increased with Cl-to-Cl{sub 2} number density ratio. This behaviour was observed previously for anodized aluminium surfaces, and was explained by the blocking of Cl recombination sites by adsorbed Cl{sub 2}. Application of this variable recombination coefficient to the modelling of high-density chlorine plasmas gives a much better agreement with measured Cl{sub 2} percent dissociations compared with predictions obtained with a recombination coefficient that is independent of plasma conditions.

  16. Initial screening of thermal desorption for soil remediation

    International Nuclear Information System (INIS)

    Yezzi, J.J. Jr.; Tafuri, A.N.; Rosenthal, S.; Troxler, W.L.

    1994-01-01

    Petroleum-contaminated soils--caused by spills, leaks, and accidental discharges--exist at many sites throughout the United States. Thermal desorption technologies which are increasingly being employed to treat these soils, have met soil cleanup criteria for a variety of petroleum products. Currently the United States Environmental Protection Agency is finalizing a technical report entitled Use of Thermal Desorption for Treating Petroleum-Contaminated Soils to assist remedial project managers, site owners, remediation contractors, and equipment vendors in evaluating the use of thermal desorption technologies for petroleum-contaminated soil applications. The report will present a three-level screening method to help a reader predict the success of applying thermal desorption at a specific site. The objective of screening level one is to determine the likelihood of success in a specific application of thermal desorption. It will take into account procedures for collecting and evaluating data on site characteristics, contaminant characteristics, soil characteristics, and regulatory requirements. This level will establish whether or not thermal desorption should be evaluated further for site remediation, whether treatment should occur on-site or off-site, and if on-site is a viable option, what system size will be most cost-effective. The scope of this paper addresses only screening level one which provides a preliminary assessment of the applicability of thermal desorption to a particular site. This topic encompasses worksheets that are an integral part of the ''user friendly'' screening process. Level one screening provides a foundation for the subsequent two levels which follow a similar ''user friendly'' worksheet approach to evaluating thermal desorption technologies and establishing costs for thermal desorption in an overall remediation project

  17. Direct pathway for sticking/desorption of H2 on Si(100)

    DEFF Research Database (Denmark)

    Kratzer, Peter; Hammer, Bjørk; Nørskov, Jens Kehlet

    1995-01-01

    The energetics of H2 interacting with the Si(100) surface is studied by means of ab initio total-energy calculations within the framework of density-functional theory. We find a direct desorption pathway from the monohydride phase that is compatible with experimental activation energies and demon......The energetics of H2 interacting with the Si(100) surface is studied by means of ab initio total-energy calculations within the framework of density-functional theory. We find a direct desorption pathway from the monohydride phase that is compatible with experimental activation energies...... and demonstrate the importance of substrate relaxation for this process. Both the transition state configuration and the barrier height depend crucially on the degree of buckling of the Si dimers on the Si(100) surface. The adsorption barrier height on the clean surface is governed by the buckling via its...

  18. Sorption and desorption of diuron in Oxisol under biochar application

    OpenAIRE

    Petter, Fabiano André; Ferreira, Tamara Santos; Sinhorin, Adilson Paulo; Lima, Larissa Borges de; Morais, Leidimar Alves de; Pacheco, Leandro Pereira

    2016-01-01

    ABSTRACT The objective of this study was to verify the kinetics of sorption and desorption of diuron in an Oxisol under application of biochar. The samples were collected in a field experiment conducted in randomized design blocks consisted of 2 base fertilization levels (0 and 400 kg∙ha−1 NPK 00-20-20 fertilizer formula) and 3 doses of biochar (0, 8 and 16 Mg∙ha−1). In the evaluation of sorption and desorption, Batch Equilibrium method was used. The kinetics of sorption and desorption of diu...

  19. Inelastic surface collisions and the desorption of massive molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Macfarlane, R D [Texas A and M Univ., College Station (USA). Dept. of Chemistry

    1983-01-01

    The interaction of high energy ions in the region of electronic stopping (1 MeV u/sup -1/) stimulates the desorption of massive molecular ions of biomolecules such as insulin. The experimental details of the measurements are given with some examples of application for analytical mass spectrometry. Studies on the role of the incident ion (accelerator beam experiments) are reviewed as well as the contribution of the matrix to the desorption-ionization process. How the electronic relaxation process couples to desorption-ionization is a central question in understanding the overall mechanism of the process.

  20. Heavy-ion induced desorption of a TiZrV coated vacuum chamber bombarded with 5 MeV/u Ar8+ beam at grazing incidence

    International Nuclear Information System (INIS)

    Hedlund, E.; Malyshev, O. B.; Westerberg, L.; Krasnov, A.; Semenov, A. S.; Leandersson, M.; Zajec, B.; Kollmus, H.; Bellachioma, M. C.; Bender, M.; Kraemer, A.; Reich-Sprenger, H.

    2009-01-01

    TiZrV nonevaporable getter (NEG) coated vacuum chambers is a new vacuum technology which is already used in many particle accelerators worldwide. This coating is also of interest for heavy-ion accelerator vacuum chambers. Heavy-ion desorption yields from an activated as well as a CO saturated NEG coated tube have been measured with 5 MeV/u Ar 8+ beam. The sticking probability of the NEG film was obtained by using the partial pressure ratios on two sides of the NEG coated tube. These ratios were compared to results of modeling of the experimental setup with test particle Monte Carlo and angular coefficient methods. The partial pressures inside the saturated NEG coated tube bombarded with heavy ions were up to 20 times larger than those inside the activated one. However, the partial pressure of methane remained the same. The value of the total desorption yield from the activated NEG coated tube is 2600 molecules/ion. The desorption yields after saturation for CH 4 , H 2 , and CO 2 were found to be very close to the yields measured after the activation, while CO increased by up to a factor of 5. The total desorption yield for the saturated tube is up to 7000 molecules/ion. The large value of the desorption yield of the activated NEG coated tube, an order of magnitude higher than the desorption yield from a stainless steel tube at normal incident angle, could be explained by the grazing incident angle

  1. Parton recombination model

    International Nuclear Information System (INIS)

    Hwa, R.C.

    1978-08-01

    Low P/sub T/ meson production in hadronic collisions is described in the framework of the parton model. The recombination of quark and antiquark is suggested as the dominant mechanism in the large x region. Phenomenological evidences for the mechanism are given. The application to meson initiated reactions yields the quark distribution in mesons. 21 references

  2. WATER ADSORPTION AND DESORPTION ISOTHERMS ON MILK POWDER: II. WHOLE MILK

    OpenAIRE

    Edgar M. Soteras; Julio Gil; Paola Yacanto; Silvana Muratona; Clidia Abaca; María G. Sustersic

    2014-01-01

    The aim of this research was the determination of adsorption and desorption isotherms of cow whole milk powder. The experiments have been carried out at 15, 25 and 40 ºC, in ranges of moisture and water activity characteristic of normal conditions in which the processes of drying, packaging and storage are developed. By studying the influence of the temperature on the experimental plots, the isosteric adsorption heat was determined. Experimental data were correlated to the referential model ...

  3. Expression and purification of recombinant nattokinase in Spodoptera frugiperda cells.

    Science.gov (United States)

    Li, Xiaoxiang; Wang, Xiaoli; Xiong, Shaoling; Zhang, Jing; Cai, Litao; Yang, Yanyan

    2007-10-01

    A recombinant baculovirus, rv-egfp-NK, containing a reporter gene encoding the enhanced green fluorescent protein (EGFP), was used to express nattokinase (NK), a fibrinolytic enzyme, in Spodoptera frugiperda (SF-9) cells. The recombinant protein also included a histidine tag for purification using Ni(2+) resins. The recombinant NK, approximately 30 kDa, retained fibrinolytic activity (60 U/ml). The integration of the EGFP expression cassette in the Bac-to-Bac system is thus an effective method for the expression and purification of recombinant NK protein in Spodoptera frugiperda insect cells.

  4. Poliovirus Polymerase Leu420 Facilitates RNA Recombination and Ribavirin Resistance

    Science.gov (United States)

    Kempf, Brian J.; Peersen, Olve B.

    2016-01-01

    ABSTRACT RNA recombination is important in the formation of picornavirus species groups and the ongoing evolution of viruses within species groups. In this study, we examined the structure and function of poliovirus polymerase, 3Dpol, as it relates to RNA recombination. Recombination occurs when nascent RNA products exchange one viral RNA template for another during RNA replication. Because recombination is a natural aspect of picornavirus replication, we hypothesized that some features of 3Dpol may exist, in part, to facilitate RNA recombination. Furthermore, we reasoned that alanine substitution mutations that disrupt 3Dpol-RNA interactions within the polymerase elongation complex might increase and/or decrease the magnitudes of recombination. We found that an L420A mutation in 3Dpol decreased the frequency of RNA recombination, whereas alanine substitutions at other sites in 3Dpol increased the frequency of recombination. The 3Dpol Leu420 side chain interacts with a ribose in the nascent RNA product 3 nucleotides from the active site of the polymerase. Notably, the L420A mutation that reduced recombination also rendered the virus more susceptible to inhibition by ribavirin, coincident with the accumulation of ribavirin-induced G→A and C→U mutations in viral RNA. We conclude that 3Dpol Leu420 is critically important for RNA recombination and that RNA recombination contributes to ribavirin resistance. IMPORTANCE Recombination contributes to the formation of picornavirus species groups and the emergence of circulating vaccine-derived polioviruses (cVDPVs). The recombinant viruses that arise in nature are occasionally more fit than either parental strain, especially when the two partners in recombination are closely related, i.e., members of characteristic species groups, such as enterovirus species groups A to H or rhinovirus species groups A to C. Our study shows that RNA recombination requires conserved features of the viral polymerase. Furthermore, a

  5. Zero-Headspace Coal-Core Gas Desorption Canister, Revised Desorption Data Analysis Spreadsheets and a Dry Canister Heating System

    Science.gov (United States)

    Barker, Charles E.; Dallegge, Todd A.

    2005-01-01

    Coal desorption techniques typically use the U.S. Bureau of Mines (USBM) canister-desorption method as described by Diamond and Levine (1981), Close and Erwin (1989), Ryan and Dawson (1993), McLennan and others (1994), Mavor and Nelson (1997) and Diamond and Schatzel (1998). However, the coal desorption canister designs historically used with this method have an inherent flaw that allows a significant gas-filled headspace bubble to remain in the canister that later has to be compensated for by correcting the measured desorbed gas volume with a mathematical headspace volume correction (McLennan and others, 1994; Mavor and Nelson, 1997).

  6. Laser desorption mass spectrometry for biomolecule detection and its applications

    Science.gov (United States)

    Winston Chen, C. H.; Sammartano, L. J.; Isola, N. R.; Allman, S. L.

    2001-08-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications.

  7. Laser desorption mass spectrometry for biomolecule detection and its applications

    International Nuclear Information System (INIS)

    Winston Chen, C.H.; Allman, S.L.; Sammartano, L.J.; Isola, N.R.

    2001-01-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications

  8. Ensuring an exit strategy: RTEL1 restricts rogue recombination.

    Science.gov (United States)

    Villeneuve, Anne M

    2008-10-17

    Success of homologous recombination-based DNA repair depends not only on recombinases, which promote invasion of the homologous DNA duplex that serves as a template for repair, but also on antirecombinases, which dismantle recombination intermediates to allow completion of repair. In this issue, Barber et al. (2008) identify a previously elusive antirecombinase activity important for maintaining genome stability in animals.

  9. Study on hydrogen absorption/desorption properties of uranium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Hiroshi; Yamaguchi, Kenji; Yamawaki, Michio [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.

    1996-10-01

    Hydrogen absorption/desorption properties of two U-Mn intermetallic compounds, U{sub 6}Mn and UMn{sub 2}, were investigated. U{sub 6}Mn absorbed hydrogen and the hydrogen desorption pressure of U{sub 6}Mn obtained from this experiment was higher than that of U, which was considered to be the effect of alloying, whereas UMn{sub 2} was not observed to absorb hydrogen up to 50 atm at room temperature. (author)

  10. Desorption by Femtosecond Laser Pulses : An Electron-Hole Effect?

    OpenAIRE

    D. M., NEWNS; T. F., HEINZ; J. A., MISEWICH; IBM Research Division, T. J. Watson Research Center; IBM Research Division, T. J. Watson Research Center; IBM Research Division, T. J. Watson Research Center

    1992-01-01

    Desorption of molecules from metal surfaces induced by femtosecond visible laser pulses has been reported. Since the lattice temperature rise is insufficient to explain desorption, an electronic mechanism is clearly responsible. It is shown that a theory based on direct coupling between the center-of-mass degree of freedom of the adsorbate and the electron-hole excitations of the substrate provides a satisfactory explanation of the various experimental findings.

  11. Effects of H2O and H2O2 on thermal desorption of tritium from stainless steel

    International Nuclear Information System (INIS)

    Quinlan, M. J.; Shmayda, W. T.; Lim, S.; Salnikov, S.; Chambers, Z.; Pollock, E.; Schroeder, W. U.

    2008-01-01

    Tritiated stainless steel was subjected to thermal desorption at various temperatures, different temperature profiles, and in the presence of different helium carrier gas additives. In all cases the identities of the desorbing tritiated species were characterized as either water-soluble or insoluble. The samples were found to contain 1.1 mCi±0.4 mCi. Approximately ninety-five percent of this activity was released in molecular water-soluble form. Additives of H 2 O or H 2 O 2 to dry helium carrier gas increase the desorption rate and lower the maximum temperature to which the sample must be heated, in order to remove the bulk of the tritium. The measurements validate a method of decontamination of tritiated steel and suggest a technique that can be used to further explore the mechanisms of desorption from tritiated metals. (authors)

  12. Water desorption of cassava starch granules: A study based on thermogravimetric analysis of aqueous suspensions and humid powders.

    Science.gov (United States)

    Ayala Valencia, Germán; Djabourov, Madeleine; do Amaral Sobral, Paulo José

    2016-08-20

    This work reports on water desorption from cassava starch in relation with the structure and conditioning of granules in suspensions or after equilibration in desiccators. The experimental work is performed by thermogravimetric analysis with isothermal and non-isothermal protocols and interpreted to derive the activation energies and desorption frequencies according to the humidity range with no adjustable parameter. The analysis points out the different types of water interacting with the starch granules and relates the drying coefficients to their microscopic structure. The work helps clarifying contradictory and partial results from the literature. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Desorption dynamics of deuterium in CuCrZr alloy

    Science.gov (United States)

    Thi Nguyen, Lan Anh; Lee, Sanghwa; Noh, S. J.; Lee, S. K.; Park, M. C.; Shu, Wataru; Pitcher, Spencer; Torcy, David; Guillermain, David; Kim, Jaeyong

    2017-12-01

    Desorption behavior of deuterium (D2) in CuCrZr alloy was investigated considering sample thickness, loading and baking temperature of deuterium followed by the ITER scopes. Cylindrical specimens of 1, 3, 5 mm thick with 4 mm diameter were exposed to deuterium at a pressure of 25 bar at 120, 240 and 350 °C for 24 h, then baked at 800 °C in a vacuum chamber maintained at a pressure lower than 10-7 Torr. Deuterium desorption characteristics such as desorption rate and amount of deuterium in the sample were estimated by analyzing the desorption peaks monitored with a residual gas analyzer (RGA), and the trapping energy of deuterium was calculated using thermal desorption spectroscopy (TDS). Secondary ion mass spectroscopy (SIMS) results showed that deuterium atoms embedded in the sample at a depth of less than 15 μm and desorbed as low as 400 °C. All absorbed deuterium atoms in the specimen were completely retrieved by dynamic pumping at 800 °C in 15 min. The desorption rate of deuterium per unit area was inversely proportional to the increment of the thickness of the sample, and was proportional to the loading temperature. Based on the assumption that a uniform distribution of interstitial sites for deuterium follows the Femi-Dirac statistics, the result of TDS demonstrated that the CuCrZr alloy has two types of trapping energies, which were estimated to be 62 and 79 kJ/mol.

  14. Impact of neutron irradiation on thermal helium desorption from iron

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xunxiang, E-mail: hux1@ornl.gov [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Field, Kevin G. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Taller, Stephen [University of Michigan, Ann Arbor, MI 48109 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); Wirth, Brian D. [Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States); University of Tennessee, Knoxville, TN 37996 (United States)

    2017-06-15

    The synergistic effect of neutron irradiation and transmutant helium production is an important concern for the application of iron-based alloys as structural materials in fission and fusion reactors. In this study, we investigated the impact of neutron irradiation on thermal helium desorption behavior in high purity iron. Single crystalline and polycrystalline iron samples were neutron irradiated in HFIR to 5 dpa at 300 °C and in BOR-60 to 16.6 dpa at 386 °C, respectively. Following neutron irradiation, 10 keV He ion implantation was performed at room temperature on both samples to a fluence of 7 × 10{sup 18} He/m{sup 2}. Thermal desorption spectrometry (TDS) was conducted to assess the helium diffusion and clustering kinetics by analyzing the desorption spectra. The comparison of He desorption spectra between unirradiated and neutron irradiated samples showed that the major He desorption peaks shift to higher temperatures for the neutron-irradiated iron samples, implying that strong trapping sites for He were produced during neutron irradiation, which appeared to be nm-sized cavities through TEM examination. The underlying mechanisms controlling the helium trapping and desorption behavior were deduced by assessing changes in the microstructure, as characterized by TEM, of the neutron irradiated samples before and after TDS measurements.

  15. Expression and characterization of recombinant ecarin.

    NARCIS (Netherlands)

    Jonebring, A.; Lange, U.; Bucha, E.; Deinum, J.; Elg, M.; Lovgren, A.

    2012-01-01

    The snake venom protease ecarin from Echis carinatus was expressed in stable transfected CHO-S cells grown in animal component free cell culture medium. Recombinant ecarin (r-ecarin) was secreted from the suspension adapted Chinese Hamster Ovary (CHO-S) host cells as a pro-protein and activation to

  16. Mechanism and Thermochemistry of Coal Char Oxidation and Desorption of Surface Oxides

    DEFF Research Database (Denmark)

    Levi, Gianluca; Causà, Mauro; Lacovig, Paolo

    2017-01-01

    The present study investigates the coal char combustion by a combination of thermochemical and X-ray photoemission spectroscopy (XPS) analyses. Thermoanalytical methods (differential thermogravimetry, differential scanning calorimetry, and temperature-programmed desorption) are used to identify...... the key reactive steps that occur upon oxidation and heating of coal char (chemisorption, structural rearrangement and switchover of surface oxides, and desorption) and their energetics. XPS is used to reveal the chemical nature of the surface oxides that populate the char surface and to monitor...... functionalities prevail. The rearrangement of epoxy during preoxidation goes together with activation of the more stable and less reactive carbon sites. Results are in good agreement with semi-lumped kinetic models of carbon oxidation, which include (1) formation of "metastable" surface oxides, (2) complex...

  17. The role of electron-stimulated desorption in focused electron beam induced deposition

    DEFF Research Database (Denmark)

    van Dorp, Willem F.; Hansen, Thomas Willum; Wagner, Jakob Birkedal

    2013-01-01

    We present the results of our study about the deposition rate of focused electron beam induced processing (FEBIP) as a function of the substrate temperature with the substrate being an electron-transparent amorphous carbon membrane. When W(CO)6 is used as a precursor it is observed that the growt......, the majority desorbs from the surface rather than dissociates to contribute to the deposit. It is important to take this into account during FEBIP experiments, for instance when determining fundamental process parameters such as the activation energy for desorption....... experiments compared to literature values is consistent with earlier findings by other authors. The discrepancy is attributed to electron-stimulated desorption, which is known to occur during electron irradiation. The data suggest that, of the W(CO)6 molecules that are affected by the electron irradiation...

  18. Organometallics and quaternary ammonium salts affect calcium ion desorption from lecithin liposome membranes

    International Nuclear Information System (INIS)

    Kral, T.E.; Kuczera, J.; Przestalski, S.

    2001-01-01

    The objective of the present work was to compare the effects of groups of tin and lead organometallic compounds and their mixtures with amphiphilic quaternary ammonium salts (QAS) on the process of calcium ion desorption from lecithin liposome membranes, as dependent on the properties of the hydrophilic and hydrophobic parts of QAS. In the investigations the method of radioactive labels was applied. Synergism and antagonism in the action of both groups of compounds were found. The effectiveness of the cooperation depended more on chain length of QAS compounds than on the size and polarity of their hydrophobic parts. The most effective of all compounds studied was a the mixture of benzyldimethylammonium chloride in a mixture with tripropyltin. Since the rate of calcium desorption proved to be a good measure of efficacy of biologically active surfactants, it seems that the conclusions reached in this paper may be useful for choosing compounds which are able to decontaminate the environment polluted with heavy metals. (orig.)

  19. Electron Stimulated Molecular Desorption of a NEG St 707 at Room Temperature

    CERN Document Server

    Le Pimpec, F; Laurent, Jean Michel

    2001-01-01

    Electron stimulated molecular desorption (ESD) from a NEG St 707 (SAES GettersTM) sample after conditioning and after saturation with isotopic carbon monoxide2,13C18O, has been studied on a laboratory setup. Measurements were performed using an electron beam of 300 eV kinetic energy, with an average electron intensity of 1.6 1015 electrons s-1. The electrons were impinging on the 15 cm2 target surface at perpendicular incidence. It is found that the desorption yields h (molecules/electron) of the characteristic gases in an UHV system (hydrogen, methane, water, carbon monoxide, carbon dioxide) for a fully activated NEG as well as for a NEG fully saturated with 13C18O are lower than for OFHC copper baked at 120oC. A small fraction only of the gas which is required to saturate the getter surface can be re-desorbed and thus appears to be accessible to ESD.

  20. Particle desorption mass spectrometric surface characterization

    International Nuclear Information System (INIS)

    Summers, W.R.

    1986-01-01

    The feasibility of utilizing 252 Cf-Particle Desorption Mass Spectrometry (PDMS) to characterize the surface region of solid samples has been evaluated. The PDMS experiment was adapted to an ultrahigh vacuum (UHV) environment and was configured so as to allow the analysis of thick as well as thin samples. This apparatus included an in situ sputter cleaning/depth profiling facility. The mass resolution was variable from 300 to 200 at 133 daltons by changing the drift length from 27 cm to 20 cm. Desorbed ions were focused by using either a dual grid assembly or an einzel lens. The overall instrumental transmission efficiency with the einzel lens operative was approximately 50%. The applicability of 252 Cf-PDMS to samples that were thick and insulating was demonstrated in the analysis of geological specimens. Pollucite, Microcline, Amblygonite, and Lepidolite were analyzed without complications associated with sample thickness or charge accumulation. Substitution occurring between the alkali metals in the environment was observed by PDMS and was corroborated by SIMS, XPS, and EMP analyses. The analysis of NBM SRM glasses addressed the suitability of combining the PDMS technique was sputter etching. This application demonstrated the ability of this technique to sense changes in the chemical environment brought about by sputter cleaning. The analysis of these samples also allowed the estimation of detection limits for lithium, rubidium, and cesium in a glass matrix as 300 ppm, 400 ppm, and 400 ppm, respectively. Sputter depth profiling combined with 252 Cf-PDMS analysis of an aluminum layer on a silicon substrate established the utility of the PDMS technique in surface characterization

  1. TPD IR studies of CO desorption from zeolites CuY and CuX

    Science.gov (United States)

    Datka, Jerzy; Kozyra, Paweł

    2005-06-01

    The desorption of CO from zeolites CuY and CuX was followed by TPD-IR method. This is a combination of temperature programmed desorption and IR spectroscopy. In this method, the status of activated zeolite (before adsorption), the process of adsorption, and the status of adsorbed molecules can be followed by IR spectroscopy, and the process of desorption (with linear temperature increase) can be followed both by IR spectroscopy and by mass spectrometry. IR spectra have shown two kinds of Cu + sites in both CuY and CuX. Low frequency (l.f.) band (2140 cm -1 in CuY and 2130 cm -1 in CuX) of adsorbed CO represents Cu + sites for which π back donation is stronger and σ donation is weaker whereas high frequency h.f. band (2160 cm -1 in CuY and 2155 cm -1 in CuX) represent Cu + sites for which π back donation is weaker and σ donation is stronger. The TPD-IR experiments evidenced that the Cu + sites represented by l.f. band bond CO more weakly than those represented by h.f. one, indicating that σ donation has more important impact to the strength of Cu +-CO bonding. On the contrary, π back donation has bigger contribution to the activation of adsorbed molecules.

  2. Site directed recombination

    Science.gov (United States)

    Jurka, Jerzy W.

    1997-01-01

    Enhanced homologous recombination is obtained by employing a consensus sequence which has been found to be associated with integration of repeat sequences, such as Alu and ID. The consensus sequence or sequence having a single transition mutation determines one site of a double break which allows for high efficiency of integration at the site. By introducing single or double stranded DNA having the consensus sequence flanking region joined to a sequence of interest, one can reproducibly direct integration of the sequence of interest at one or a limited number of sites. In this way, specific sites can be identified and homologous recombination achieved at the site by employing a second flanking sequence associated with a sequence proximal to the 3'-nick.

  3. A rapid screening method to monitor expression of various recombinant proteins from prokaryotic and eukaryotic expression systems using MALDI-TOF mass spectrometry

    DEFF Research Database (Denmark)

    Jebanathirajah, J.A.; Andersen, S.; Blagoev, B.

    2002-01-01

    Rapid methods using matrix-assisted laser desorption ionization-time-of-flight mass spectrometry to monitor recombinant protein expression from various prokaryotic and eukaryotic cell culture systems were devised. Intracellular as well as secreted proteins from both induced and constitutive...

  4. Nonradiative recombination in semiconductors

    CERN Document Server

    Abakumov, VN; Yassievich, IN

    1991-01-01

    In recent years, great progress has been made in the understandingof recombination processes controlling the number of excessfree carriers in semiconductors under nonequilibrium conditions. As a result, it is now possible to give a comprehensivetheoretical description of these processes. The authors haveselected a number of experimental results which elucidate theunderlying physical problems and enable a test of theoreticalmodels. The following topics are dealt with: phenomenological theory ofrecombination, theoretical models of shallow and deep localizedstates, cascade model of carrier captu

  5. Recombination epoch revisited

    International Nuclear Information System (INIS)

    Krolik, J.H.

    1989-01-01

    Previous studies of cosmological recombination have shown that this process produces as a by-product a highly superthermal population of Ly-alpha photons which retard completion of recombination. Cosmological redshifting was thought to determine the frequency distribution of the photons, while two-photon decay of hydrogen's 2s state was thought to control their numbers. It is shown here that frequency diffusion due to photon scattering dominate the cosmological redshift in the frequency range near line center which fixes the ratio of ground state to excited state population, while incoherent scattering into the far-red damping wing effectively destroys Ly-alpha photons as a rate which is competitive with two-photon decay. The former effect tends to hold back recombination, while the latter tends to accelerate it; the net results depends on cosmological parameters, particularly the combination Omega(b) h/sq rt (2q0), where Omega(b) is the fraction of the critical density provided by baryons. 18 references

  6. Dielectronic recombination theory

    International Nuclear Information System (INIS)

    LaGattuta, K.J.

    1991-01-01

    A theory now in wide use for the calculation of dielectronic recombination cross sections (σ DR ) and rate coefficients (α DR ) was one introduced originally by Feshbach for nuclear physics applications, and then later adapted for atomic scattering problems by Hahn. In the following, we briefly review this theory in a very general form, which allows one to account for the effects of overlapping and interacting resonances, as well as continuum-continuum coupling. An extension of our notation will then also allow for the inclusion of the effects of direct radiative recombination, along with a treatment of the interference between radiative and dielectronic recombination. Other approaches to the calculation of σ DR have been described by Fano and by Seaton. We will not consider those theories here. Calculations of α DR have progressed considerably over the last 25 years, since the early work of Burgess. Advances in the reliability of theoretical predictions have also been promoted recently b a variety of direct laboratory measurements of σ DR . While the measurements of σ DR for δn ≠ 0 excitations have tended to agree very well with calculations, the case of δn = 0 has been much problematic. However, by invoking a mechanism originally proposed by Jacobs, which takes into account the effect of stray electric fields on high Rydberg states (HRS) participating in the DR process, new calculations have improved the agreement between theory and experiment for these cases. Nevertheless, certain discrepancies still remain

  7. Recombinant human bone morphogenetic protein induces bone formation

    International Nuclear Information System (INIS)

    Wang, E.A.; Rosen, V.; D'Alessandro, J.S.; Bauduy, M.; Cordes, P.; Harada, T.; Israel, D.I.; Hewick, R.M.; Kerns, K.M.; LaPan, P.; Luxenberg, D.P.; McQuaid, D.; Moutsatsos, I.K.; Nove, J.; Wozney, J.M.

    1990-01-01

    The authors have purified and characterized active recombinant human bone morphogenetic protein (BMP) 2A. Implantation of the recombinant protein in rats showed that a single BMP can induce bone formation in vivo. A dose-response and time-course study using the rat ectopic bone formation assay revealed that implantation of 0.5-115 μg of partially purified recombinant human BMP-2A resulted in cartilage by day 7 and bone formation by day 14. The time at which bone formation occurred was dependent on the amount of BMP-2A implanted; at high doses bone formation could be observed at 5 days. The cartilage- and bone-inductive activity of the recombinant BMP-2A is histologically indistinguishable from that of bone extracts. Thus, recombinant BMP-2A has therapeutic potential to promote de novo bone formation in humans

  8. Oxygen desorption from YBa2Cu3O(7-x) and Bi2CaSr2Cu2O(8 + delta) superconductors

    Science.gov (United States)

    Mesarwi, A.; Levenson, L. L.; Ignatiev, A.

    1991-01-01

    Oxygen desorption experiments from YBa2Cu3O(7-x) (YBCO) and Bi2CaSr2Cu2O(8 + delta) (BSCCO) superconductors were carried out using a quadrupole mass spectrometer for monitoring the desorbing species and X-ray photoemission spectroscopy for surface characterization. Molecular oxygen was found to desorb from both superconductors following photoirradiation with ultraviolet/optical radiation and subsequent heating at over 150 C. Both YBCO and BSCCO were found to have similar oxygen desorption rates and similar activation energies. The desorption data as well as the X-ray photoemission data indicate that the oxygen desorption is not intrinsic to the superconductors but rather due to molecular oxygen entrapped in the material.

  9. Data on the evolutionary history of the V(DJ recombination-activating protein 1 – RAG1 coupled with sequence and variant analyses

    Directory of Open Access Journals (Sweden)

    Abhishek Kumar

    2016-09-01

    Full Text Available RAG1 protein is one of the key component of RAG complex regulating the V(DJ recombination. There are only few studies for RAG1 concerning evolutionary history, detailed sequence and mutational hotspots. Herein, we present out datasets used for the recent comprehensive study of RAG1 based on sequence, phylogenetic and genetic variant analyses (Kumar et al., 2015 [1]. Protein sequence alignment helped in characterizing the conserved domains and regions of RAG1. It also aided in unraveling ancestral RAG1 in the sea urchin. Human genetic variant analyses revealed 751 mutational hotspots, located both in the coding and the non-coding regions. For further analysis and discussion, see (Kumar et al., 2015 [1].

  10. Kinetics of Hydrogen Absorption and Desorption in Titanium

    Directory of Open Access Journals (Sweden)

    Suwarno Suwarno

    2017-10-01

    Full Text Available Titanium is reactive toward hydrogen forming metal hydride which has a potential application in      energy storage and conversion. Titanium hydride has been widely studied for hydrogen storage, thermal storage, and battery electrodes applications. A special interest is using titanium for hydrogen production in a hydrogen sorption-enhanced steam reforming of natural gas. In the present work, non-isothermal dehydrogenation kinetics of titanium hydride and kinetics of hydrogenation in gaseous flow at isothermal conditions were investigated. The hydrogen desorption was studied using temperature desorption spectroscopy (TDS while the hydrogen absorption and desorption in gaseous flow were studied by temperature programmed desorption (TPD. The present work showed that the path of dehydrogenation of the TiH2 is d®b®a hydride phase with possible overlapping steps occurred. The fast hydrogen desorption rate observed at the TDS main peak temperature were correlated with the fast transformation of the d-TiH1.41 to b-TiH0.59. In the gaseous flow, hydrogen absorption and desorption were related to the transformation of b-TiH0.59 Û d-TiH1.41 with 2 wt.% hydrogen reversible content. Copyright © 2017 BCREC Group. All rights reserved Received: 21st November 2016; Revised: 20th March 2017; Accepted: 9th April 2017; Available online: 27th October 2017; Published regularly: December 2017 How to Cite: Suwarno, S., Yartys, V.A. (2017. Kinetics of Hydrogen Absorption and Desorption in Titanium. Bulletin of Chemical Reaction Engineering & Catalysis, 12 (3: 312-317  (doi:10.9767/bcrec.12.3.810.312-317

  11. Adsorption and desorption dynamics of citric acid anions in soil

    KAUST Repository

    Oburger, E.

    2011-07-26

    The functional role of organic acid anions in soil has been intensively investigated, with special focus on (i) microbial respiration and soil carbon dynamics, (ii) nutrient solubilization or (iii) metal detoxification and reduction of plant metal uptake. Little is known about the interaction dynamics of organic acid anions with the soil matrix and the potential impact of adsorption and desorption processes on the functional significance of these effects. The aim of this study was to characterize experimentally the adsorption and desorption dynamics of organic acid anions in five agricultural soils differing in iron and aluminium oxide contents and using citrate as a model carboxylate. Results showed that both adsorption and desorption processes were fast in all soils, reaching a steady state within approximately 1 hour. However, for a given total soil citrate concentration (ct) the steady state was critically dependent on the starting conditions of the experiment, whether most of the citrate was initially present in solution (cl) or held on the solid phase (cs). Specifically, desorption-led processes resulted in significantly smaller steady-state solution concentrations than adsorption-led processes, indicating that hysteresis occurred. As it is not possible to distinguish between different adsorption and desorption pools in soil experimentally, a new dynamic hysteresis model that relies only on measured soil solution concentrations was developed. The model satisfactorily explained experimental data and was able to predict dynamic adsorption and desorption behaviour. To demonstrate its use, we applied the model to two relevant situations involving exudation and microbial degradation. The study highlighted the complex nature of citrate adsorption and desorption dynamics in soil. We conclude that existing models need to incorporate both temporal and hysteresis components to describe realistically the role and fate of organic acids in soil processes. © 2011 The

  12. The laser desorption/laser ionization mass spectra of some methylated xanthines and the laser desorption of caffeine and theophylline from thin layer chromatography plates

    Science.gov (United States)

    Rogers, Kevin; Milnes, John; Gormally, John

    1993-02-01

    Laser desorption/laser ionization time-of-flight mass spectra of caffeine, theophylline, theobromine and xanthine are reported. These mass spectra are compared with published spectra obtained using electron impact ionization. Mass spectra of caffeine and theophylline obtained by IR laser desorption from thin layer chromatography plates are also described. The laser desorption of materials from thin layer chromatography plates is discussed.

  13. Influence of acid rain components on radiocesium-137 desorption from Cetraria islandica (L. Ach. lichen

    Directory of Open Access Journals (Sweden)

    Miljanić Šćepan S.

    2012-01-01

    Full Text Available Desorption of 137Cs from Cetraria islandica (L. Ach. lichen was performed by five consecutive desorptions with five identical solution volumes. Solutions of H2SO4, HNO3 and their mixtures, with pH 4.61, 5.15 and 5.75 were used for desorption. The desorbed amount of 137Cs (average value, all solutions used from lichen, for a given pH value was 49.2% for pH 4.61; 47.0% for pH 5.15 and 47.6% for pH 5.75. The obtained values of the desorbed amount of 137Cs from lichen are in accordance with the data obtained in earlier work, when 46.2 % 137Cs was desorbed from lichen for pH 3.75, and 47.2% was desorbed for pH 2.87. A higher percentage of 59.8%, obtained for pH 2.00 indicates increased activity of H+ ions. The amount of desorbed 137Cs from lichen using solutions corresponding to acid rain cannot be lower than the stated values as they contain other substances besides the acid solutions used in this work.

  14. Sorption-desorption behavior of polybrominated diphenyl ethers in soils

    International Nuclear Information System (INIS)

    Olshansky, Yaniv; Polubesova, Tamara; Vetter, Walter; Chefetz, Benny

    2011-01-01

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that are commonly found in commercial and household products. These compounds are considered persistent organic pollutants. In this study, we used 4,4'-dibromodiphenyl ether (BDE-15) as a model compound to elucidate the sorption and desorption behavior of PBDEs in soils. The organic carbon-normalized sorption coefficient (K OC ) of BDE-15 was more than three times higher for humin than for bulk soils. However, pronounced desorption hysteresis was obtained mainly for bulk soils. For humin, increasing concentration of sorbed BDE-15 resulted in decreased desorption. Our data illustrate that BDE-15 and probably other PBDEs exhibit high sorption affinity to soils. Moreover, sorption is irreversible and thus PBDEs can potentially accumulate in the topsoil layer. We also suggest that although humin is probably a major sorbent for PBDEs in soils, other humic materials are also responsible for their sequestration. - Highlights: → BDE-15 exhibited pronounced desorption hysteresis. → BDE-15 sowed higher sorption affinity to humin as compared to the bulk soils. → Sequestration of PBDEs depends on soil organic matter constitutes other than humin. - Pronounced desorption hysteresis was observed for BDE-15 in natural soils.

  15. Sorption and desorption of diuron in Oxisol under biochar application

    Directory of Open Access Journals (Sweden)

    Fabiano André Petter

    Full Text Available ABSTRACT The objective of this study was to verify the kinetics of sorption and desorption of diuron in an Oxisol under application of biochar. The samples were collected in a field experiment conducted in randomized design blocks consisted of 2 base fertilization levels (0 and 400 kg∙ha−1 NPK 00-20-20 fertilizer formula and 3 doses of biochar (0, 8 and 16 Mg∙ha−1. In the evaluation of sorption and desorption, Batch Equilibrium method was used. The kinetics of sorption and desorption of diuron, total organic carbon, fulvic acid, humic acid and humin, pH and partition coefficient to organic carbon were evaluated. The Freundlich isotherm was adjusted appropriately to describe diuron sorption kinetics in all the studied treatments. The application of biochar provided increment in the sorption (Kf and reduction in the desorption of diuron in 64 and 44%, respectively. This effect is attributed to the biochar contribution to the total organic carbon and C-humin and of these to diuron through hydrophobic interactions and hydrogen bonds. The positive correlation between the partition coefficient to organic carbon and Kf confirms the importance of soil organic compartment in the sorption of diuron. There was no competition of NPK fertilizer for the same sorption site of diuron. The increase and reduction in sorption and desorption, respectively, show that the application of biochar is an important alternative for the remediation of soil leaching of diuron, especially in sandy soils.

  16. Desorption of absorbed iron in bean root and leaf tissues

    International Nuclear Information System (INIS)

    Jooste, J.H.; De Bruyn, J.A.

    1979-01-01

    The effect of different desorption media on the amount of absorbed Fe (from a solution of FeCl 3 in 0,5 mM CaCl 2 ) retained by leaf discs and excised root tips of bean plants was investigated. Attempts were also made to determine the effect of desorption on the intracellular distribution of Fe. Desorption in water or an FeCl 3 solution had no pronounced effect on the amount of absorbed Fe retained by either the leaf or root tissues. However, Na 2 -EDTA was able to desorb a considerable portion of the absorbed Fe, especially in root tissue. This applies to Fe absorbed from solutions of FeCl 3 and Fe-EDDHA. Desorption by the chelate removed Fe from practically all the different particulate fractions of both root and leaf tissues, but desorption following the longer absorption periods resulted in an increase in the Fe content of the 'soluble' fraction. The possibility that Na 2 -EDTA causes an increased permeability of cell membranes seems likely. The view that removal of Ca by the chelate causes this increase in permeability could not be confirmed [af

  17. Influence of surface coverage on the chemical desorption process

    Energy Technology Data Exchange (ETDEWEB)

    Minissale, M.; Dulieu, F., E-mail: francois.dulieu@obspm.fr [LERMA, Université de Cergy Pontoise et Observatoire de Paris, UMR 8112 du CNRS. 5, mail Gay Lussac, 95031 Cergy Pontoise (France)

    2014-07-07

    In cold astrophysical environments, some molecules are observed in the gas phase whereas they should have been depleted, frozen on dust grains. In order to solve this problem, astrochemists have proposed that a fraction of molecules synthesized on the surface of dust grains could desorb just after their formation. Recently the chemical desorption process has been demonstrated experimentally, but the key parameters at play have not yet been fully understood. In this article, we propose a new procedure to analyze the ratio of di-oxygen and ozone synthesized after O atoms adsorption on oxidized graphite. We demonstrate that the chemical desorption efficiency of the two reaction paths (O+O and O+O{sub 2}) is different by one order of magnitude. We show the importance of the surface coverage: for the O+O reaction, the chemical desorption efficiency is close to 80% at zero coverage and tends to zero at one monolayer coverage. The coverage dependence of O+O chemical desorption is proved by varying the amount of pre-adsorbed N{sub 2} on the substrate from 0 to 1.5 ML. Finally, we discuss the relevance of the different physical parameters that could play a role in the chemical desorption process: binding energy, enthalpy of formation, and energy transfer from the new molecule to the surface or to other adsorbates.

  18. Sorption-desorption dynamics of radiocaesium in organic matter soils

    International Nuclear Information System (INIS)

    Valcke, E.; Cremers, A.

    1994-01-01

    A systematic study has been carried out on the radiocaesium sorption properties of 25 soils (forest, peat) covering organic matter (OM) contents in the range of 10-97%. Predictions are made for radiocaesium partitioning between micaceous Frayed Edge Sites (FES) and regular exchange sites (RES) on the basis of specific radiocaesium interception potentials of the soil and overall exchange capacity. It is shown that for soils with a very high OM content (>80%), significant fractions are present in a readily reversible form in the OM phase. In soils of low-medium OM content (<40%), only a very minor fraction is present in the OM exchange complex. Experimental findings, based on a desorption screening with a variety of desorption agents are in agreement with these predictions. On the basis of a study of sorption kinetics, some additional tools are available for identifying problem soils. In cases of very high OM content, radiocaesium adsorption is completed within hours demonstrating the involvement of the OM sites. In soils for which interception occurs in the FES, sorption continues to proceed for periods of 2-3 weeks. In conclusion, some examples are presented on radiocaesium desorption using ion exchangers as radiocaesium sinks in promoting desorption. For a peaty soil, near quantitative desorption is accomplished. For forest soils with OM contents in a range of 10-40%, fixation levels of 30-50% are demonstrated

  19. Fundamental Studies of Recombinant Hydrogenases

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W. [Univ. of Georgia, Athens, GA (United States)

    2014-01-25

    This research addressed the long term goals of understanding the assembly and organization of hydrogenase enzymes, of reducing them in size and complexity, of determining structure/function relationships, including energy conservation via charge separation across membranes, and in screening for novel H2 catalysts. A key overall goal of the proposed research was to define and characterize minimal hydrogenases that are produced in high yields and are oxygen-resistant. Remarkably, in spite of decades of research carried out on hydrogenases, it is not possible to readily manipulate or design the enzyme using molecular biology approaches since a recombinant form produced in a suitable host is not available. Such resources are essential if we are to understand what constitutes a “minimal” hydrogenase and design such catalysts with certain properties, such as resistance to oxygen, extreme stability and specificity for a given electron donor. The model system for our studies is Pyrococcus furiosus, a hyperthermophile that grows optimally at 100°C, which contains three different nickel-iron [NiFe-] containing hydrogenases. Hydrogenases I and II are cytoplasmic while the other, MBH, is an integral membrane protein that functions to both evolve H2 and pump protons. Three important breakthroughs were made during the funding period with P. furiosus soluble hydrogenase I (SHI). First, we produced an active recombinant form of SHI in E. coli by the co-expression of sixteen genes using anaerobically-induced promoters. Second, we genetically-engineered P. furiosus to overexpress SHI by an order of magnitude compared to the wild type strain. Third, we generated the first ‘minimal’ form of SHI, one that contained two rather than four subunits. This dimeric form was stable and active, and directly interacted with a pyruvate-oxidizing enzyme with any intermediate electron carrier. The research resulted in five peer-reviewed publications.

  20. Site-selective conjugation of an anticoagulant aptamer to recombinant albumins and maintenance of neonatal Fc receptor binding

    Science.gov (United States)

    Schmøkel, Julie; Voldum, Anders; Tsakiridou, Georgia; Kuhlmann, Matthias; Cameron, Jason; Sørensen, Esben S.; Wengel, Jesper; Howard, Kenneth A.

    2017-05-01

    Aptamers are an attractive molecular medicine that offers high target specificity. Nucleic acid-based aptamers, however, are prone to nuclease degradation and rapid renal excretion that require blood circulatory half-life extension enabling technologies. The long circulatory half-life, predominately facilitated by engagement with the cellular recycling neonatal Fc receptor (FcRn), and ligand transport properties of albumin promote it as an attractive candidate to improve the pharmacokinetic profile of aptamers. This study investigates the effect of Cys34 site-selective covalent attachment of a factor IXa anticoagulant aptamer on aptamer functionality and human FcRn (hFcRn) engagement using recombinant human albumin (rHA) of either a wild type (WT) or an engineered human FcRn high binding variant (HB). Albumin-aptamer conjugates, connected covalently through a heterobifunctional succinimidyl 4-(N-maleimidomethyl)cyclohexane-1-carboxylate linker, were successfully prepared and purified by high performance liquid chromatography as confirmed by gel electrophoresis band-shift analysis and matrix-assisted laser desorption/ionization time of flight. Minimal reduction (∼25%) in activity of WT-linked aptamer to that of aptamer alone was found using an anticoagulant activity assay measuring temporal levels of activated partial thrombin. Covalent albumin-aptamer conjugation, however, substantially compromized binding to hFcRn, to 10% affinity of that of non-conjugated WT, determined by biolayer interferometry. Binding could be rescued by aptamer conjugation to recombinant albumin engineered for higher FcRn affinity (HB) that exhibited an 8-fold affinity compared to WT alone. This work describes a novel albumin-based aptamer delivery system whose hFcRn binding can be increased using a HB engineered albumin.

  1. Recombinant Innovation and Endogenous Transitions

    OpenAIRE

    Koen Frenken; Luis R. Izquierdo; Paolo Zeppini

    2012-01-01

    We propose a model of technological transitions based on two different types of innovations. Branching innovations refer to technological improvements along a particular path, while recombinant innovations represent fusions of multiple paths. Recombinant innovations create “short-cuts” which reduce switching costs allowing agents to escape a technological lock-in. As a result, recombinant innovations speed up technological progress allowing transitions that are impossible with only branching ...

  2. In vitro V(D)J recombination: signal joint formation.

    Science.gov (United States)

    Cortes, P; Weis-Garcia, F; Misulovin, Z; Nussenzweig, A; Lai, J S; Li, G; Nussenzweig, M C; Baltimore, D

    1996-11-26

    The first step of V(D)J recombination, specific cleavage at the recombination signal sequence (RSS), can be carried out by the recombination activating proteins RAG1 and RAG2. In vivo, the cleaved coding and signal ends must be rejoined to generate functional antigen receptors and maintain chromosomal integrity. We have investigated signal joint formation using deletion and inversion substrates in a cell free system. RAG1 and RAG2 alone or in combination were unable to generate signal joints. However, RAG1 and RAG2 complemented with nuclear extracts were able to recombine an extrachromosomal substrate and form precise signal joints. The in vitro reaction resembled authentic V(D)J recombination in being Ku-antigen-dependent.

  3. A study of the process of desorption of hexavalent chromium

    Directory of Open Access Journals (Sweden)

    W.B. Amorim

    2003-09-01

    Full Text Available In this work the process of desorption of hexavalent chromium, a toxic metal ion, from the marine algae Sargassum sp, following biosorption experiments 2³ factorial design was studied. A technique was applied to three eluents: HCl, H2SO4 and EDTA. Three factors of importance were evaluated: concentration of eluent, the ratio between mass of biosorbent and volume of eluent (S/L and process time. A statistical analysis of the experimental results showed that the three variables evaluated are significant for all three eluents. The models for chromium desorption were validated, as the results agreed well with the observed values. Through use of the response surface methodology, a factorial design based optimization technique; it was possible to identify the most suitable eluent and the interval of values for the process variables that resulted in the most significant desorption of chromium, which is relevant information for work aiming at process optimization.

  4. Study of the mechanisms of matrix assisted laser desorption / ionization

    International Nuclear Information System (INIS)

    Manuelli, Pascal

    1995-01-01

    This research thesis aims at a better knowledge of some aspects of a complex mechanism: the matrix-assisted laser desorption/ionization (MALDI). The author first proposes a comparative analysis of results obtained by time-of-flight (TOF) mass spectrometry and by Fourier transform mass spectrometry. He reports the study of the matrix role (notably a polymeric matrix) as a matter submitted to laser desorption. In this respect, the influence of the incident wavelength has been studied. The author also reports a comparative of ions produced by matrix laser desorption (study performed by Fourier transform mass spectrometry) and of neutral molecules (study performed by flash pyrolysis coupled with gas chromatography and with mass spectrometry). Finally, results obtained on derivatives and complexes based on beta-cyclodextrins highlight benefits as well as limitations of this technique [fr

  5. Electron stimulated desorption of gases at technological surfaces of aluminium

    International Nuclear Information System (INIS)

    Ding, M.Q.; Williams, E.M.

    1989-01-01

    The release of gas by electron bombardment at aluminium alloy surfaces in vacuum -9 torr has been investigated for a range of treatments including bakeout and glow discharge cleaning. Particular attention has been given to the role of continuous electron bombardment, with current densities and electron energies of up to 1.5 mA cm -2 and 2.0 keV, respectively, over the 10 cm 2 of surface area under irradiation. The observations of desorption efficiency, defined as the number of desorbed molecules per incident electron, conform to a model involving a dynamic balance between adsorption and desorption, with contributions to adsorption from both surface and sub-surface gas. Continuous electron bombardment promotes a surface with low desorption efficiency, -5 mol/electron, however, the conditioning cycle is accelerated significantly by glow discharge treatment. There is evidence of some short-term memory when the samples are exposed to air. (author)

  6. Expression of recombinant Antibodies

    Directory of Open Access Journals (Sweden)

    André eFrenzel

    2013-07-01

    Full Text Available Recombinant antibodies are highly specific detection probes in research, diagnostics and have emerged over the last two decades as the fastest growing class of therapeutic proteins. Antibody generation has been dramatically accelerated by in vitro selection systems, particularly phage display. An increasing variety of recombinant production systems have been developed, ranging from Gram-negative and positive bacteria, yeasts and filamentous fungi, insect cell lines, mammalian cells to transgenic plants and animals. Currently, almost all therapeutic antibodies are still produced in mammalian cell lines in order to reduce the risk of immunogenicity due to altered, non-human glycosylation patterns. However, recent developments of glycosylation-engineered yeast, insect cell lines and transgenic plants are promising to obtain antibodies with human-like post-translational modifications. Furthermore, smaller antibody fragments including bispecific antibodies without any glycosylation are successfully produced in bacteria and have advanced to clinical testing. The first therapeutic antibody products from a non-mammalian source can be expected in coming next years. In this review, we focus on current antibody production systems including their usability for different applications.

  7. Coverage dependent desorption dynamics of deuterium on Si(100) surfaces: interpretation with a diffusion-promoted desorption model.

    Science.gov (United States)

    Matsuno, T; Niida, T; Tsurumaki, H; Namiki, A

    2005-01-08

    We studied coverage dependence of time-of-flight (TOF) spectra of D2 molecules thermally desorbed from the D/Si(100) surface. The mean translational energies Et of desorbed D2 molecules were found to increase from 0.20+/-0.05 eV to 0.40+/-0.04 eV as the desorption coverage window was decreased from 1.0 ML> or =thetaD> or =0.9 ML to 0.2 ML> or =thetaD> or =0 ML, being consistent with the kinetics switch predicted in the interdimer mechanism. The measured TOF spectra were deconvoluted into 2H, 3H, and 4H components by a curve fitting method along the principle of detailed balance. As a result, it turned out that the desorption kinetics changes from the 4H to the 3H situation at high coverage above thetaD=0.9 ML, while the 2H desorption is dominant for a quite wide coverage region up to thetaD=0.8 ML. A dynamic desorption mechanism by which the desorption is promoted by D-atom diffusion to dangling bonds was proposed. 2005 American Institute of Physics.

  8. On the relict recombination lines

    International Nuclear Information System (INIS)

    Bershtejn, I.N.; Bernshtejn, D.N.; Dubrovich, V.K.

    1977-01-01

    Accurate numerical calculation of intensities and profiles of hydrogen recombination lines of cosmological origin is made. Relie radiation distortions stipulated by recombination quantum release at the irrevocable recombination are investigated. Mean number calculation is given for guantums educing for one irrevocably-lost electron. The account is taken of the educed quantums interraction with matter. The main quantum-matter interrraction mechanisms are considered: electronic blow broadening; free-free, free-bound, bound-bound absorptions Recombination dynamics is investigated depending on hydrogen density and total density of all the matter kinds in the Universe

  9. Long-term desorption of trichloroethylene from flint clay using multiplexed optical detection

    International Nuclear Information System (INIS)

    Stager, M.P.; Perram, G.P.

    1999-01-01

    The long-term desorption of trichloroethylene (TCE) from powdered flint clay was examined using a multiplexed, phase sensitive infrared technique which provided a gas phase detection limit of 0.0045 torr for continuous monitoring of the desorption process for at least 3 days. The vapor phase TCE concentrations as a function of desorption time exhibit a significant deviation from Langmuir kinetics. The desorption process is adequately described by bonding sites with a gamma distribution for the desorption rate coefficients. The mean desorption rate for powdered flint clay at 25°C is k d = 0.50 ± 0.02 h −1 . (author)

  10. Modelling of Convective Process of Water Desorption from Polystyrene

    International Nuclear Information System (INIS)

    Stakic, M.; Nikolic, A.

    2008-01-01

    This study presents a mathematical model developed to evaluate the influence of structural and operational factors on convective dehydration process (desorption of liquid phase from capillary-porous material), as well as the possibility to utilize this model for the case of water desorption from polystyrene cation resin CG-8. The model accounts for unsteady one-dimensional simultaneous heat and mass transfer between the gas (air) and the solid phase (resin). The identification of effective transport properties for the considered fixed bed of material (resin CG 8) is discussed. To this purpose available data from the literature are used. (author)

  11. Sorption and desorption of diuron in Oxisol under biochar application

    OpenAIRE

    Petter,Fabiano André; Ferreira,Tamara Santos; Sinhorin,Adilson Paulo; Lima,Larissa Borges de; Morais,Leidimar Alves de; Pacheco,Leandro Pereira

    2016-01-01

    ABSTRACT The objective of this study was to verify the kinetics of sorption and desorption of diuron in an Oxisol under application of biochar. The samples were collected in a field experiment conducted in randomized design blocks consisted of 2 base fertilization levels (0 and 400 kg∙ha−1 NPK 00-20-20 fertilizer formula) and 3 doses of biochar (0, 8 and 16 Mg∙ha−1). In the evaluation of sorption and desorption, Batch Equilibrium method was used. The kinetics of sorpti...

  12. Counterion adsorption and desorption rate of a charged macromolecule

    Science.gov (United States)

    Shi, Yu; Yang, Jingfa; Zhao, Jiang

    The rate constant of counterion adsorption to and desorption from a synthetic polyelectrolyte, polystyrene sulfonate (PSS-), is measured in aqueous solution by single molecule fluorescence spectroscopy. The results show that both adsorption and desorption rate of counterions have strong dependence on polymer concentration, salt concentration as well as the molecular weight of polyelectrolytes. The results clearly demonstrate that the contribution of electrostatic interaction and the translational entropy to the distribution of counterions of a polyelectrolyte molecule. The information is helpful to the understanding of polyelectrolyte physics. National Natural Science Foundation of China.

  13. Heavy-Ion-Induced Electronic Desorption of Gas from Metals

    CERN Document Server

    Molvik, A W; Mahner, E; Kireeff Covo, M; Bellachioma, M C; Bender, M; Bieniosek, F M; Hedlund, E; Krämer, A; Kwan, J; Malyshev, O B; Prost, L; Seidl, P A; Westenskow, G; Westerberg, L

    2007-01-01

    During heavy-ion operation in several particle accelerators worldwide, dynamic pressure rises of orders of magnitude were triggered by lost beam ions that bombarded the vacuum chamber walls. This ion-induced molecular desorption, observed at CERN, GSI, and BNL, can seriously limit the ion beam lifetime and intensity of the accelerator. From dedicated test stand experiments we have discovered that heavy-ion-induced gas desorption scales with the electronic energy loss (dEe/dx) of the ions slowing down in matter; but it varies only little with the ion impact angle, unlike electronic sputtering.

  14. Bulk-mediated surface diffusion: non-Markovian desorption dynamics

    International Nuclear Information System (INIS)

    Revelli, Jorge A; Budde, Carlos E; Prato, Domingo; Wio, Horacio S

    2005-01-01

    Here we analyse the dynamics of adsorbed molecules within the bulk-mediated surface diffusion framework, when the particle's desorption mechanism is characterized by a non-Markovian process, while the particle's adsorption as well as its motion in the bulk is governed by Markovian dynamics. We study the diffusion of particles in both semi-infinite and finite cubic lattices, analysing the conditional probability to find the system on the reference absorptive plane as well as the surface dispersion as functions of time. The results are compared with known Markovian cases showing the differences that can be exploited to distinguish between Markovian and non-Markovian desorption mechanisms in experimental situations

  15. Though active on RINm5F insulinoma cells and cultured pancreatic islets, recombinant IL-22 fails to modulate cytotoxicity and disease in a protocol of streptozotocin-induced experimental diabetes.

    Directory of Open Access Journals (Sweden)

    Anika eBerner

    2016-01-01

    Full Text Available Interleukin (IL-22 is a cytokine displaying tissue protective and pro-regenerative functions in various preclinical disease models. Anti-bacterial, pro-proliferative, and anti-apoptotic properties mediated by activation of the transcription factor signal transducer and activator of transcription (STAT-3 are key to biological functions of this IL-10 family member. Herein, we introduce RINm5F insulinoma cells as rat ß-cell line that, under the influence of IL-22, displays activation of STAT3 with induction of its downstream gene targets Socs3, Bcl3, and Reg3ß. In addition, IL-22 also activates STAT1 in this cell type. To refine those observations, IL-22 biological activity was evaluated using ex vivo cultivated murine pancreatic islets. In accord with data on RINm5F cells, islet exposure to IL-22 activated STAT3 and upregulation of STAT3-inducible Socs3, Bcl3, and STEAP4 was evident under those conditions. As these observations supported the hypothesis that IL-22 may exert protective functions in toxic ß-cell injury, application of IL-22 was investigated in murine multiple-low-dose streptozotocin (STZ-induced diabetes. For that purpose, recombinant IL-22 was administered thrice either immediately before and at disease onset (at d4, d6, d8 or closely thereafter (at d8, d10, d12. These two IL-22-treatment periods coincide with two early peaks of ß-cell injury detectable in this model. Notably, none of the two IL-22-treatment strategies affected diabetes incidence or blood glucose levels in STZ-treated mice. Moreover, pathological changes in islet morphology analyzed 28 days after disease induction were not ameliorated by IL-22 administration. Taken together, despite being active on rat RINm5F insulinoma cells and murine pancreatic islets, recombinant IL-22 fails to protect pancreatic ß-cells in the tested protocols from toxic effects of STZ and thus is unable to ameliorate disease in the widely used model of STZ-induced diabetes.

  16. Adsorption and Desorption of Dinitrotoluene on Activated Carbon

    National Research Council Canada - National Science Library

    Ho, Patience C; Daw, C. S

    1987-01-01

    .... Both carbons proved to be excel lent adsorbents +or aqueous DNT. The solvents tested +or extracting the adsorbed DNT were water, acetone, and methanol, both individually and in mixtures with each...

  17. Catalytic hydrogen recombination for nuclear containments

    International Nuclear Information System (INIS)

    Koroll, G.W.; Lau, D.W.P.; Dewit, W.A.; Graham, W.R.C.

    1994-01-01

    Catalytic recombiners appear to be a credible option for hydrogen mitigation in nuclear containments. The passive operation, versatility and ease of back fitting are appealing for existing stations and new designs. Recently, a generation of wet-proofed catalyst materials have been developed at AECL which are highly specific to H 2 -O 2 , are active at ambient temperatures and are being evaluated for containment applications. Two types of catalytic recombiners were evaluated for hydrogen removal in containments based on the AECL catalyst. The first is a catalytic combustor for application in existing air streams such as provided by fans or ventilation systems. The second is an autocatalytic recombiner which uses the enthalpy of reaction to produce natural convective flow over the catalyst elements. Intermediate-scale results obtained in 6 m 3 and 10 m 3 spherical and cylindrical vessels are given to demonstrate self-starting limits, operating limits, removal capacity, scaling parameters, flow resistance, mixing behaviour in the vicinity of an operating recombiner and sensitivity to poisoning, fouling and radiation. (author). 13 refs., 10 figs

  18. Meiotic recombination hotspots - a comparative view.

    Science.gov (United States)

    Choi, Kyuha; Henderson, Ian R

    2015-07-01

    During meiosis homologous chromosomes pair and undergo reciprocal genetic exchange, termed crossover. Meiotic recombination has a profound effect on patterns of genetic variation and is an important tool during crop breeding. Crossovers initiate from programmed DNA double-stranded breaks that are processed to form single-stranded DNA, which can invade a homologous chromosome. Strand invasion events mature into double Holliday junctions that can be resolved as crossovers. Extensive variation in the frequency of meiotic recombination occurs along chromosomes and is typically focused in narrow hotspots, observed both at the level of DNA breaks and final crossovers. We review methodologies to profile hotspots at different steps of the meiotic recombination pathway that have been used in different eukaryote species. We then discuss what these studies have revealed concerning specification of hotspot locations and activity and the contributions of both genetic and epigenetic factors. Understanding hotspots is important for interpreting patterns of genetic variation in populations and how eukaryotic genomes evolve. In addition, manipulation of hotspots will allow us to accelerate crop breeding, where meiotic recombination distributions can be limiting. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  19. Protection of mice against the highly pathogenic VVIHD-J by DNA and fowlpox recombinant vaccines, administered by electroporation and intranasal routes, correlates with serum neutralizing activity.

    Science.gov (United States)

    Bissa, Massimiliano; Quaglino, Elena; Zanotto, Carlo; Illiano, Elena; Rolih, Valeria; Pacchioni, Sole; Cavallo, Federica; De Giuli Morghen, Carlo; Radaelli, Antonia

    2016-10-01

    The control of smallpox was achieved using live vaccinia virus (VV) vaccine, which successfully eradicated the disease worldwide. As the variola virus no longer exists as a natural infection agent, mass vaccination was discontinued after 1980. However, emergence of smallpox outbreaks caused by accidental or deliberate release of variola virus has stimulated new research for second-generation vaccine development based on attenuated VV strains. Considering the closely related animal poxviruses that also arise as zoonoses, and the increasing number of unvaccinated or immunocompromised people, a safer and more effective vaccine is still required. With this aim, new vectors based on avian poxviruses that cannot replicate in mammals should improve the safety of conventional vaccines, and protect from zoonotic orthopoxvirus diseases, such as cowpox and monkeypox. In this study, DNA and fowlpox (FP) recombinants that expressed the VV L1R, A27L, A33R, and B5R genes were generated (4DNAmix, 4FPmix, respectively) and tested in mice using novel administration routes. Mice were primed with 4DNAmix by electroporation, and boosted with 4FPmix applied intranasally. The lethal VV IHD-J strain was then administered by intranasal challenge. All of the mice receiving 4DNAmix followed by 4FPmix, and 20% of the mice immunized only with 4FPmix, were protected. The induction of specific humoral and cellular immune responses directly correlated with this protection. In particular, higher anti-A27 antibodies and IFNγ-producing T lymphocytes were measured in the blood and spleen of the protected mice, as compared to controls. VV IHD-J neutralizing antibodies in sera from the protected mice suggest that the prime/boost vaccination regimen with 4DNAmix plus 4FPmix may be an effective and safe mode to induce protection against smallpox and poxvirus zoonotic infections. The electroporation/intranasal administration routes contributed to effective immune responses and mouse survival. Copyright

  20. Partitioning and desorption behavior of polycyclic aromatic hydrocarbons from disparate sources

    International Nuclear Information System (INIS)

    Reeves, W.R.; McDonald, T.J.; Cizmas, L.; Donnelly, K.C.

    2004-01-01

    Contaminated sediments pose a unique challenge for risk assessment or remediation because the overlying water column may transport contaminants offsite or to ecological receptors. This research compares the behavior of polycyclic aromatic hydrocarbons (PAHs) on marine sediments from two sites. The first site was affected by shipping activities and the second was impacted by a creosote seep. Organic carbon:water partitioning coefficients (K oc values) were measured with three solutions. Desorption was measured using Tenax beads. PAHs from the ship channel had lower K oc values than those from the creosote facility. For example, the average log K oc value of ship channel pyrene was significantly lower than that of creosote facility pyrene (4.39±0.35 and 5.29±0.09, respectively, when tested in 5 mM calcium chloride). These results were consistent with the greater desorption of pyrene, phenanthrene and benzo(a)pyrene from the ship channel than from the creosote facility sediments. Organic compound desorption from sediments can be considered to be a two-stage process, with a labile fraction that desorbs quickly and a refractory fraction that desorbs much more slowly. In both sediments, more than 75% of the benzo(a)pyrene was found to have partitioned into the refractory phase. The amounts of phenanthrene and pyrene that partitioned into the refractory phase were lower. Linear correlations of log K oc with log (C R /C L ) (where C R and C L are the fractions of the compound in the refractory and labile phases, respectively, at time zero) showed that partitioning measurements made with the US EPA's Toxicity Characteristic Leaching Procedure fluid (US EPA, 1996) most closely matched predictions of desorption behavior. The data imply that with a larger data set, it may be possible to relate simple partitioning measurements to desorption behavior. Partitioning measurements were used to predict water concentrations. Despite having higher concentrations of carcinogenic PAHs

  1. Dissociative recombination of dications

    International Nuclear Information System (INIS)

    Seiersen, K.; Heber, O.; Jensen, M.J.; Safvan, C.P.; Andersen, L. H.

    2003-01-01

    Dissociative recombination (DR) of doubly-charged positive ions has been studied at the heavy ion storage ring ASTRID. Low-energy electrons were scattered on the dication of the N 2 molecule, and the absolute cross section was measured in the energy range of 10 -4 -50 eV. From the measured cross section, a thermal rate coefficient of 5.8x10 -7 cm 3 s -1 at 300 K was extracted. Furthermore, we present new results on the CO 2+ DR rate, and a summary and comparison of measured DR rate coefficients for both the singly and doubly-charged ions of CO, CO 2 , and N 2 is presented

  2. Cell biology of mitotic recombination

    DEFF Research Database (Denmark)

    Lisby, Michael; Rothstein, Rodney

    2015-01-01

    Homologous recombination provides high-fidelity DNA repair throughout all domains of life. Live cell fluorescence microscopy offers the opportunity to image individual recombination events in real time providing insight into the in vivo biochemistry of the involved proteins and DNA molecules as w...

  3. Hadron Correlations and Parton Recombination

    Energy Technology Data Exchange (ETDEWEB)

    Fries, R.J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States)]. E-mail: rjfries@comp.tamu.edu

    2007-02-15

    Parton recombination has been found to be an extremely useful model to understand hadron production at the Relativistic Heavy Ion Collider. It is particularly important to explore its connections with hard processes. This article reviews some of the aspects of the quark recombination model and places particular emphasis on hadron correlations.

  4. Recombination properties of dislocations in GaN

    Science.gov (United States)

    Yakimov, Eugene B.; Polyakov, Alexander Y.; Lee, In-Hwan; Pearton, Stephen J.

    2018-04-01

    The recombination activity of threading dislocations in n-GaN with different dislocation densities and different doping levels was studied using electron beam induced current (EBIC). The recombination velocity on a dislocation, also known as the dislocation recombination strength, was calculated. The results suggest that dislocations in n-GaN giving contrast in EBIC are charged and surrounded by a space charge region, as evidenced by the observed dependence of dislocation recombination strength on dopant concentration. For moderate (below ˜108 cm-2) dislocation densities, these defects do not primarily determine the average diffusion length of nonequilibrium charge carriers, although locally, dislocations are efficient recombination sites. In general, it is observed that the effect of the growth method [standard metalorganic chemical vapor deposition (MOCVD), epitaxial lateral overgrowth versions of MOCVD, and hydride vapor phase epitaxy] on the recombination activity of dislocations is not very pronounced, although the average diffusion lengths can widely differ for various samples. The glide of basal plane dislocations at room temperature promoted by low energy electron irradiation does not significantly change the recombination properties of dislocations.

  5. Double positivity to bee and wasp venom: improved diagnostic procedure by recombinant allergen-based IgE testing and basophil activation test including data about cross-reactive carbohydrate determinants.

    Science.gov (United States)

    Eberlein, Bernadette; Krischan, Lilian; Darsow, Ulf; Ollert, Markus; Ring, Johannes

    2012-07-01

    Specific IgE (sIgE) antibodies to both bee and wasp venom can be due to a sensitivity to both insect venoms or due to cross-reactive carbohydrate determinants (CCDs). Investigating whether a basophil activation test (BAT) with both venoms as well as with bromelain and horseradish peroxidase (HRP) or recombinant allergen-based IgE testing can improve the diagnostic procedure. Twenty-two Hymenoptera-venom allergic patients with sIgE antibodies to both bee and wasp venom were studied. sIgE antibodies to MUXF3 CCD, bromelain, HRP, rApi m 1, and rVes v 5 were determined, and a BAT (Flow2 CAST) with venom extracts, bromelain, and HRP was performed. Further recombinant allergen-based IgE testing was done by using an ELISA, if required. The reactivity of basophils was calculated from the insect venom concentration at half-maximum stimulation. Double positivity/double negativity/single positivity to rApi m 1 and rVes v 5 was seen in 12/1/9 patients. Further recombinant allergen-based IgE testing in the last ones revealed positive results to the other venom in all cases except one. BAT was double positive/double negative/single positive in 6/2/14 patients. Four patients with negative results in sIgE antibodies to CCDs had positive results in BAT. BAT with bromelain/HRP showed a sensitivity of 50%/81% and a specificity of 91%/90%. Component-resolved IgE testing elucidates the pattern of double positivity, showing a majority of true double sensitizations independent of CCD sensitization. BAT seems to add more information about the culprit insect even if the true clinical relevance of BAT is not completely determined because of ethical limitations on diagnostic sting challenges. BAT with HRP is a good method to determine sensitivity to CCDs. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  6. Thermal desorption of deuterium from Be, and Be with helium bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, A.V.; Van Veen, A.; Busker, G.J. [Delft Univ. of Technology (Netherlands). Interfaculty Reactor Inst.

    1998-01-01

    Deuterium desorption measurements carried out on a single-crystalline beryllium sample are presented. Deuterium ions were implanted at room temperature at the energy of 0.7 and 1.2 keV up to doses ranging from 10{sup 19} to 3.6 x 10{sup 21} m{sup -2}. In order to eliminate the influence of the beryllium-oxide surface layer, before the implantation the surface of the sample was cleaned by argon sputtering. After the implantation the sample was annealed up to 1200 K at a constant rate of 10 K/s. Deuterium released from the sample was monitored by a calibrated quadrupole mass-spectrometer. The desorption spectra revealed two different contributions. One is a well defined and very narrow peak centered around 450 K. This peak is observed only at high implantation doses > 7.8 x 10{sup 20} m{sup -2}, which is close to the deuterium saturation limit of 0.3 D/Be and is related to deuterium release from blisters or interconnected bubbles. The activation energy of 1.1 eV and the threshold implantation dose are consistent with the values reported in literature. The second contribution in the release spectra is found i