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Sample records for autophagic conjugation system

  1. Transcriptional stimulation of rate-limiting components of the autophagic pathway improves plant fitness

    Czech Academy of Sciences Publication Activity Database

    Minina, E. A.; Moschou, P. N.; Vetukuri, R. R.; Sanchez-Vera, V.; Cardoso, C.; Liu, Q.; Elander, P. H.; Dalman, K.; Beganovic, M.; Lindberg Yilmaz, J.; Marmon, S.; Shabala, S.; Suarez, M.; Ljung, K.; Novák, Ondřej; Shabala, S.; Stymne, S.; Hofius, D.; Bozhkov, P. V.

    2018-01-01

    Roč. 69, č. 6 (2018), s. 1415-1432 ISSN 0022-0957 Institutional support: RVO:61389030 Keywords : Aging * ATG genes * Autophagy * Autophagy-related ubiquitin-like conjugation systems * Biomass * Oil content * Ratelimiting components of autophagic flux * Seed yield * Stress resistance * Transcriptional regulation Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Genetics and heredity (medical genetics to be 3) Impact factor: 5.830, year: 2016

  2. Structure Property Relationships in Organic Conjugated Systems

    OpenAIRE

    O'Neill, Luke

    2008-01-01

    A series of pi(п) conjugated oligomers containing 1 to 6 monomer units were studied by absorption and photoluminescence spectroscopies. The results are discussed and examined with regard to the variation of the optical properties with the increase of effective conjugation length. It was found that there was a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length. The relationships are in good agreement with the si...

  3. Structure Property Relationships in Organic Conjugated Systems

    OpenAIRE

    O'Neill, Luke; Lynch, Patrick; McNamara, Mary

    2005-01-01

    A series of π conjugated oligomers were studied by absorption and photoluminescence spectroscopy. A linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Sto...

  4. Assessing Basal and Acute Autophagic Responses in the Adult Drosophila Nervous System: The Impact of Gender, Genetics and Diet on Endogenous Pathway Profiles.

    Directory of Open Access Journals (Sweden)

    Eric P Ratliff

    Full Text Available The autophagy pathway is critical for the long-term homeostasis of cells and adult organisms and is often activated during periods of stress. Reduced pathway efficacy plays a central role in several progressive neurological disorders that are associated with the accumulation of cytotoxic peptides and protein aggregates. Previous studies have shown that genetic and transgenic alterations to the autophagy pathway impacts longevity and neural aggregate profiles of adult Drosophila. In this study, we have identified methods to measure the acute in vivo induction of the autophagy pathway in the adult fly CNS. Our findings indicate that the genotype, age, and gender of adult flies can influence pathway responses. Further, we demonstrate that middle-aged male flies exposed to intermittent fasting (IF had improved neuronal autophagic profiles. IF-treated flies also had lower neural aggregate profiles, maintained more youthful behaviors and longer lifespans, when compared to ad libitum controls. In summary, we present methodology to detect dynamic in vivo changes that occur to the autophagic profiles in the adult Drosophila CNS and that a novel IF-treatment protocol improves pathway response in the aging nervous system.

  5. Accurate conjugate gradient methods for families of shifted systems

    NARCIS (Netherlands)

    Eshof, J. van den; Sleijpen, G.L.G.

    2003-01-01

    We consider the solution of the linear system (ATA + σI)xσ = ATb, for various real values of σ. This family of shifted systems arises, for example, in Tikhonov regularization and computations in lattice quantum chromodynamics. For each single shift σ this system can be solved using the conjugate

  6. Accurate conjugate gradient methods for families of shifted systems

    NARCIS (Netherlands)

    Eshof, J. van den; Sleijpen, G.L.G.

    We present an efficient and accurate variant of the conjugate gradient method for solving families of shifted systems. In particular we are interested in shifted systems that occur in Tikhonov regularization for inverse problems since these problems can be sensitive to roundoff errors. The

  7. Conjugate dynamical systems: classical analogue of the quantum energy translation

    International Nuclear Information System (INIS)

    Torres-Vega, Gabino

    2012-01-01

    An aspect of quantum mechanics that has not been fully understood is the energy shift generated by the time operator. In this study, we introduce the use of the eigensurfaces of dynamical variables and commutators in classical mechanics to study the classical analogue of the quantum translation of energy. We determine that there is a conjugate dynamical system that is conjugate to Hamilton's equations of motion, and then we generate the analogue of the time operator and use it in the translation of points along the energy direction, i.e. the classical analogue of the Pauli theorem. The theory is illustrated with a nonlinear oscillator model. (paper)

  8. 21 CFR 862.1115 - Urinary bilirubin and its conjugates (nonquantitative) test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urinary bilirubin and its conjugates... Clinical Chemistry Test Systems § 862.1115 Urinary bilirubin and its conjugates (nonquantitative) test system. (a) Identification. A urinary bilirubin and its conjugates (nonquantitative) test system is a...

  9. An Autophagic Flux Probe that Releases an Internal Control.

    Science.gov (United States)

    Kaizuka, Takeshi; Morishita, Hideaki; Hama, Yutaro; Tsukamoto, Satoshi; Matsui, Takahide; Toyota, Yuichiro; Kodama, Akihiko; Ishihara, Tomoaki; Mizushima, Tohru; Mizushima, Noboru

    2016-11-17

    Macroautophagy is an intracellular degradation system that utilizes the autophagosome to deliver cytoplasmic components to the lysosome. Measuring autophagic activity is critically important but remains complicated and challenging. Here, we have developed GFP-LC3-RFP-LC3ΔG, a fluorescent probe to evaluate autophagic flux. This probe is cleaved by endogenous ATG4 proteases into equimolar amounts of GFP-LC3 and RFP-LC3ΔG. GFP-LC3 is degraded by autophagy, while RFP-LC3ΔG remains in the cytosol, serving as an internal control. Thus, autophagic flux can be estimated by calculating the GFP/RFP signal ratio. Using this probe, we re-evaluated previously reported autophagy-modulating compounds, performed a high-throughput screen of an approved drug library, and identified autophagy modulators. Furthermore, we succeeded in measuring both induced and basal autophagic flux in embryos and tissues of zebrafish and mice. The GFP-LC3-RFP-LC3ΔG probe is a simple and quantitative method to evaluate autophagic flux in cultured cells and whole organisms. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Autophagic pathways and metabolic stress.

    Science.gov (United States)

    Kaushik, S; Singh, R; Cuervo, A M

    2010-10-01

    Autophagy is an essential intracellular process that mediates degradation of intracellular proteins and organelles in lysosomes. Autophagy was initially identified for its role as alternative source of energy when nutrients are scarce but, in recent years, a previously unknown role for this degradative pathway in the cellular response to stress has gained considerable attention. In this review, we focus on the novel findings linking autophagic function with metabolic stress resulting either from proteins or lipids. Proper autophagic activity is required in the cellular defense against proteotoxicity arising in the cytosol and also in the endoplasmic reticulum, where a vast amount of proteins are synthesized and folded. In addition, autophagy contributes to mobilization of intracellular lipid stores and may be central to lipid metabolism in certain cellular conditions. In this review, we focus on the interrelation between autophagy and different types of metabolic stress, specifically the stress resulting from the presence of misbehaving proteins within the cytosol or in the endoplasmic reticulum and the stress following a lipogenic challenge. We also comment on the consequences that chronic exposure to these metabolic stressors could have on autophagic function and on how this effect may underlie the basis of some common metabolic disorders. © 2010 Blackwell Publishing Ltd.

  11. Liposomal Conjugates for Drug Delivery to the Central Nervous System

    Directory of Open Access Journals (Sweden)

    Frieder Helm

    2015-04-01

    Full Text Available Treatments of central nervous system (CNS diseases often fail due to the blood–brain barrier. Circumvention of this obstacle is crucial for any systemic treatment of such diseases to be effective. One approach to transfer drugs into the brain is the use of colloidal carrier systems—amongst others, liposomes. A prerequisite for successful drug delivery by colloidal carriers to the brain is the modification of their surface, making them invisible to the reticuloendothelial system (RES and to target them to specific surface epitopes at the blood–brain barrier. This study characterizes liposomes conjugated with cationized bovine serum albumin (cBSA as transport vectors in vitro in porcine brain capillary endothelial cells (PBCEC and in vivo in rats using fluorescently labelled liposomes. Experiments with PBCEC showed that sterically stabilized (PEGylated liposomes without protein as well as liposomes conjugated to native bovine serum albumin (BSA were not taken up. In contrast, cBSA-liposomes were taken up and appeared to be concentrated in intracellular vesicles. Uptake occurred in a concentration and time dependent manner. Free BSA and free cBSA inhibited uptake. After intravenous application of cBSA-liposomes, confocal fluorescence microscopy of brain cryosections from male Wistar rats showed fluorescence associated with liposomes in brain capillary surrounding tissue after 3, 6 and 24 h, for liposomes with a diameter between 120 and 150 nm, suggesting successful brain delivery of cationized-albumin coupled liposomes.

  12. Structure and optical bandgap relationship of π-conjugated systems.

    Directory of Open Access Journals (Sweden)

    André Leitão Botelho

    Full Text Available In bulk heterojunction photovoltaic systems both the open-circuit voltage as well as the short-circuit current, and hence the power conversion efficiency, are dependent on the optical bandgap of the electron-donor material. While first-principles methods are computationally intensive, simpler model Hamiltonian approaches typically suffer from one or more flaws: inability to optimize the geometries for their own input; absence of general, transferable parameters; and poor performance for non-planar systems. We introduce a set of new and revised parameters for the adapted Su-Schrieffer-Heeger (aSSH Hamiltonian, which is capable of optimizing geometries, along with rules for applying them to any [Formula: see text]-conjugated system containing C, N, O, or S, including non-planar systems. The predicted optical bandgaps show excellent agreement to UV-vis spectroscopy data points from literature, with a coefficient of determination [Formula: see text], a mean error of -0.05 eV, and a mean absolute deviation of 0.16 eV. We use the model to gain insights from PEDOT, fused thiophene polymers, poly-isothianaphthene, copolymers, and pentacene as sources of design rules in the search for low bandgap materials. Using the model as an in-silico design tool, a copolymer of benzodithiophenes along with a small-molecule derivative of pentacene are proposed as optimal donor materials for organic photovoltaics.

  13. Implementing the conjugate gradient algorithm on multi-core systems

    NARCIS (Netherlands)

    Wiggers, W.A.; Bakker, Vincent; Kokkeler, Andre B.J.; Smit, Gerardus Johannes Maria; Nurmi, J.; Takala, J.; Vainio, O.

    2007-01-01

    In linear solvers, like the conjugate gradient algorithm, sparse-matrix vector multiplication is an important kernel. Due to the sparseness of the matrices, the solver runs relatively slow. For digital optical tomography (DOT), a large set of linear equations have to be solved which currently takes

  14. Characterization of Autophagic Responses in Drosophila melanogaster.

    Science.gov (United States)

    Xu, T; Kumar, S; Denton, D

    2017-01-01

    Drosophila is an excellent model system for studying autophagy during animal development due to the availability of genetic reagents and opportunity for in vivo cell biological analysis. The regulation and mechanism of autophagy are highly evolutionarily conserved and the role of autophagy has been characterized during various stages of Drosophila development as well as following starvation. Studies in Drosophila have revealed novel insights into the role of distinct components of the autophagy machinery. This chapter describes protocols for examining autophagy during Drosophila development. A crucial step in the induction of autophagy is the incorporation of Atg8a into the autophagosome. This can be measured as autophagic puncta using live fluorescent imaging, immunostaining, or immunoblot analysis of LC3/Atg8a processing. The level of autophagy can also be examined using other specific components of the autophagy pathway as markers detected by immunofluorescent imaging. Based on the distinct morphology of autophagy, it can also be examined by transmission electron microscopy. In addition, one of the advantages of using Drosophila as a model is the ability to undertake genetic analysis of individual components of the autophagy machinery. Current approaches that can be used to monitor autophagy, including the overall flux and individual steps in Drosophila melanogaster, will be discussed. © 2017 Elsevier Inc. All rights reserved.

  15. Conjugate whole-body scanning system for quantitative measurement of organ distribution in vivo

    International Nuclear Information System (INIS)

    Tsui, B.M.W.; Chen, C.T.; Yasillo, N.J.; Ortega, C.J.; Charleston, D.B.; Lathrop, K.A.

    1979-01-01

    The determination of accurate, quantitative, biokinetic distribution of an internally dispersed radionuclide in humans is important in making realistic radiation absorbed dose estimates, studying biochemical transformations in health and disease, and developing clinical procedures indicative of abnormal functions. In order to collect these data, a whole-body imaging system is required which provides both adequate spatial resolution and some means of absolute quantitation. Based on these considerations, a new whole-body scanning system has been designed and constructed that employs the conjugate counting technique. The conjugate whole-body scanning system provides an efficient and accurate means of collecting absolute quantitative organ distribution data of radioactivity in vivo

  16. Theory of optical transitions in conjugated polymers. I. Ideal systems.

    Science.gov (United States)

    Barford, William; Marcus, Max

    2014-10-28

    We describe a theory of linear optical transitions in conjugated polymers. The theory is based on three assumptions. The first is that the low-lying excited states of conjugated polymers are Frenkel excitons coupled to local normal modes, described by the Frenkel-Holstein model. Second, we assume that the relevant parameter regime is ℏω ≪ J, i.e., the adiabatic regime, and thus the Born-Oppenheimer factorization of the electronic and nuclear degrees of freedom is generally applicable. Finally, we assume that the Condon approximation is valid, i.e., the exciton-polaron wavefunction is essentially independent of the normal modes. Using these assumptions we derive an expression for an effective Huang-Rhys parameter for a chain (or chromophore) of N monomers, given by S(N) = S(1)/IPR, where S(1) is the Huang-Rhys parameter for an isolated monomer. IPR is the inverse participation ratio, defined by IPR = (∑(n)|Ψ(n)|(4))(-1), where Ψ(n) is the exciton center-of-mass wavefunction. Since the IPR is proportional to the spread of the exciton center-of-mass wavefunction, this is a key result, as it shows that S(N) decreases with chain length. As in molecules, in a polymer S(N) has two interpretations. First, ℏωS(N) is the relaxation energy of an excited state caused by its coupling to the normal modes. Second, S(N) appears in the definition of an effective Franck-Condon factor, F(0v)(N) = S(N)(v)exp ( - S(N))/v! for the vth vibronic manifold. We show that the 0 - 0 and 0 - 1 optical intensities are proportional to F00(N) and F01(N), respectively, and thus the ratio of the 0 - 1 to 0 - 0 absorption and emission intensities are proportional to S(N). These analytical results are checked by extensive DMRG calculations and found to be generally valid, particularly for emission. However, for large chain lengths higher-lying quasimomentum exciton states become degenerate with the lowest vibrational excitation of the lowest exciton state. When this happens there is

  17. The Autophagic Machinery in Enterovirus Infection.

    Science.gov (United States)

    Lai, Jeffrey K F; Sam, I-Ching; Chan, Yoke Fun

    2016-01-27

    The Enterovirus genus of the Picornaviridae family comprises many important human pathogens, including polioviruses, rhinovirus, enterovirus A71, and enterovirus D68. They cause a wide variety of diseases, ranging from mild to severe life-threatening diseases. Currently, no effective vaccine is available against enteroviruses except for poliovirus. Enteroviruses subvert the autophagic machinery to benefit their assembly, maturation, and exit from host. Some enteroviruses spread between cells via a process described as autophagosome-mediated exit without lysis (AWOL). The early and late phases of autophagy are regulated through various lipids and their metabolizing enzymes. Some of these lipids and enzymes are specifically regulated by enteroviruses. In the present review, we summarize the current understanding of the regulation of autophagic machinery by enteroviruses, and provide updates on recent developments in this field.

  18. compounds with N=N, C≡C or conjugated double-bonded systems

    Indian Academy of Sciences (India)

    Unusual products in the reactions of phosphorus(III) compounds with. N=N, C≡C or conjugated double-bonded systems. K C KUMARA SWAMY,* E BALARAMAN, M PHANI PAVAN, N N BHUVAN KUMAR,. K PRAVEEN KUMAR and N SATISH KUMAR. School of Chemistry, University of Hyderabad, Hyderabad 500 046.

  19. Conjugate gradient type methods for linear systems with complex symmetric coefficient matrices

    Science.gov (United States)

    Freund, Roland

    1989-01-01

    We consider conjugate gradient type methods for the solution of large sparse linear system Ax equals b with complex symmetric coefficient matrices A equals A(T). Such linear systems arise in important applications, such as the numerical solution of the complex Helmholtz equation. Furthermore, most complex non-Hermitian linear systems which occur in practice are actually complex symmetric. We investigate conjugate gradient type iterations which are based on a variant of the nonsymmetric Lanczos algorithm for complex symmetric matrices. We propose a new approach with iterates defined by a quasi-minimal residual property. The resulting algorithm presents several advantages over the standard biconjugate gradient method. We also include some remarks on the obvious approach to general complex linear systems by solving equivalent real linear systems for the real and imaginary parts of x. Finally, numerical experiments for linear systems arising from the complex Helmholtz equation are reported.

  20. Research algorithm for synthesis of double conjugation optical systems in the Gauss region

    Directory of Open Access Journals (Sweden)

    A. B. Ostrun

    2014-01-01

    Full Text Available The article focuses on the research of variable magnification optical systems of sophistic class - so-called double conjugation systems. When the magnification changes, they provide two pairs of fixed conjugate planes, namely object and image, as well as entrance and exit pupils. Similar systems are used in microscopy and complex schemes, where it is necessary to conform the pupils of contiguous removable optical components. Synthesis of double conjugation systems in Gauss region is not an easy task. To ensure complete immobility of the exit pupil in the system there should be three movable components or components with variable optical power.Analysis of the literature shows that the design of double conjugation optical system in the paraxial region has been neglected, all methods are not completely universal and suitable for automation.Based on the foregoing, the research and development of a universal method for automated synthesis of double conjugation systems in Gauss region formulated as an objective of the present work seem to be a challenge.To achieve this goal a universal algorithm is used. It is based on the fact that the output coordinates of paraxial rays are multilinear functions of optical surfaces and of axial thicknesses between surfaces. It allows us to create and solve a system of multilinear equations in semi-automatic mode to achieve the chosen values of paraxial characteristics.As a basic scheme for the synthesis a five-component system has been chosen with extreme fixed components and three mobile "internal" ones. The system was considered in two extreme states of moving parts. Initial values of axial thicknesses were taken from Hopkins' patent. Optical force five components were considered unknown. For calculation the system of five equations was created, which allowed us to obtain a certain back focal length, to provide the specified focal length and a fixed position of the exit pupil at a fixed entrance pupil.The scheme

  1. Autophagic clearance of bacterial pathogens: molecular recognition of intracellular microorganisms.

    Science.gov (United States)

    Pareja, Maria Eugenia Mansilla; Colombo, Maria I

    2013-01-01

    Autophagy is involved in several physiological and pathological processes. One of the key roles of the autophagic pathway is to participate in the first line of defense against the invasion of pathogens, as part of the innate immune response. Targeting of intracellular bacteria by the autophagic machinery, either in the cytoplasm or within vacuolar compartments, helps to control bacterial proliferation in the host cell, controlling also the spreading of the infection. In this review we will describe the means used by diverse bacterial pathogens to survive intracellularly and how they are recognized by the autophagic molecular machinery, as well as the mechanisms used to avoid autophagic clearance.

  2. Autophagic cell death: Loch Ness monster or endangered species?

    Science.gov (United States)

    Shen, Han-Ming; Codogno, Patrice

    2011-05-01

    The concept of autophagic cell death was first established based on observations of increased autophagic markers in dying cells. The major limitation of such a morphology-based definition of autophagic cell death is that it fails to establish the functional role of autophagy in the cell death process, and thus contributes to the confusion in the literature regarding the role of autophagy in cell death and cell survival. Here we propose to define autophagic cell death as a modality of non-apoptotic or necrotic programmed cell death in which autophagy serves as a cell death mechanism, upon meeting the following set of criteria: (i) cell death occurs without the involvement of apoptosis; (ii) there is an increase of autophagic flux, and not just an increase of the autophagic markers, in the dying cells; and (iii) suppression of autophagy via both pharmacological inhibitors and genetic approaches is able to rescue or prevent cell death. In light of this new definition, we will discuss some of the common problems and difficulties in the study of autophagic cell death and also revisit some well-reported cases of autophagic cell death, aiming to achieve a better understanding of whether autophagy is a real killer, an accomplice or just an innocent bystander in the course of cell death. At present, the physiological relevance of autophagic cell death is mainly observed in lower eukaryotes and invertebrates such as Dictyostelium discoideum and Drosophila melanogaster. We believe that such a clear definition of autophagic cell death will help us study and understand the physiological or pathological relevance of autophagic cell death in mammals.

  3. Enhancement of phase-conjugate reflectivity using Zeeman coherence in highly degenerate molecular systems

    International Nuclear Information System (INIS)

    Mukherjee, Nandini

    2010-01-01

    A comprehensive theoretical analysis is developed for the vectorial phase conjugation using resonant four-wave mixing (FWM) in a highly degenerate rotational vibrational molecular system. The dynamic Stark shifts, saturation, and Doppler broadening are included for a realistic analysis. It is shown that the electromagnetically induced multilevel coherence controls the nonlinear wave mixing yielding interesting results for the phase conjugate (PC) reflectivity. It turns out that the efficiency of the PC reflectivity is decided by the relative phase of the Zeeman coherence and the population grating. When these two contributions are aligned in phase by a small detuning of the pump frequency, a large PC reflectivity (∼20%) is obtained with moderate pump intensity (∼500 mW/cm 2 ).

  4. Relationships for electron-vibrational coupling in conjugated π organic systems

    Science.gov (United States)

    O'Neill, L.; Lynch, P.; McNamara, M.; Byrne, H. J.

    2005-06-01

    A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transition energies, it was observed that the Stokes shift also exhibited a well-defined relationship with increasing conjugation length, implying a correlation between the electron-vibrational coupling and chain length. This correlation is further examined using Raman spectroscopy, whereby the integrated Raman scattering is seen to behave superlinearly with chain length. There is a clear indication that the vibrational activity and thus nonradiative decay processes are controllable through molecular structure. The correlations between the Stokes energies and the vibrational structure are also observed in a selection of PPV based polymers and a clear trend of increasing luminescence efficiency with decreasing vibrational activity and Stokes shift is observable. The implications of such structure property relationships in terms of materials design are discussed.

  5. Vibrational Coupling in Conjugated π Systems with a view to Optimization of Fluorescence Yield through Phonon Confinement

    OpenAIRE

    O'Neill, Luke; Lynch, Patrick; McNamara, Mary; Byrne, Hugh J.

    2005-01-01

    A series of π conjugated systems were studied by absorption, photoluminescence and vibrational spectroscopy. As is common for these systems, a linear relationship between the positioning of the absorption and photoluminescence maxima plotted against inverse conjugation length is observed. The relationships are in good agreement with the simple particle in a box method, one of the earliest descriptions of the properties of one-dimensional organic molecules. In addition to the electronic transi...

  6. In vivo imaging and quantitative monitoring of autophagic flux in tobacco BY-2 cells.

    Science.gov (United States)

    Hanamata, Shigeru; Kurusu, Takamitsu; Okada, Masaaki; Suda, Akiko; Kawamura, Koki; Tsukada, Emi; Kuchitsu, Kazuyuki

    2013-01-01

    Autophagy has been shown to play essential roles in the growth, development and survival of eukaryotic cells. However, simple methods for quantification and visualization of autophagic flux remain to be developed in living plant cells. Here, we analyzed the autophagic flux in transgenic tobacco BY-2 cell lines expressing fluorescence-tagged NtATG8a as a marker for autophagosome formation. Under sucrose-starved conditions, the number of punctate signals of YFP-NtATG8a increased, and the fluorescence intensity of the cytoplasm and nucleoplasm decreased. Conversely, these changes were not observed in BY-2 cells expressing a C-terminal glycine deletion mutant of the NtATG8a protein (NtATG8aΔG). To monitor the autophagic flux more easily, we generated a transgenic BY-2 cell line expressing NtATG8a fused to a pH-sensitive fluorescent tag, a tandem fusion of the acid-insensitive RFP and the acid-sensitive YFP. In sucrose-rich conditions, both fluorescent signals were detected in the cytoplasm and only weakly in the vacuole. In contrast, under sucrose-starved conditions, the fluorescence intensity of the cytoplasm decreased, and the RFP signal clearly increased in the vacuole, corresponding to the fusion of the autophagosome to the vacuole and translocation of ATG8 from the cytoplasm to the vacuole. Moreover, we introduce a novel simple easy way to monitor the autophagic flux non-invasively by only measuring the ratio of fluorescence of RFP and YFP in the cell suspension using a fluorescent image analyzer without microscopy. The present in vivo quantitative monitoring system for the autophagic flux offers a powerful tool for determining the physiological functions and molecular mechanisms of plant autophagy induced by environmental stimuli.

  7. Pharmacokinetics of a ternary conjugate based pH-responsive 10-HCPT prodrug nano-micelle delivery system

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2017-11-01

    Full Text Available A pH-responsive conjugate based 10-hydroxycamptothecin-thiosemicarbazide-polyethene glycol 2000 (10-HCPT-hydro-PEG nano-micelles were prepared in our previous study. In the present study, ultra-performance liquid chromatography (UPLC-MS method is developed to investigate its pharmacokinetics and biodistribution in tumor bearing mice. The results demonstrated that the conjugate circulated for a much longer time in the blood circulation system than commercial 10-HCPT injection, and bioavailability was significantly improved compared with 10-HCPT. In vivo biodistribution study showed that the conjugate could enhance the targeting and residence time in tumor site.

  8. Direct calculation of self-consistent π bond orders in conjugated systems and pairing relations

    International Nuclear Information System (INIS)

    Castro, A.F.

    1982-01-01

    Pairing relations in excited states of conjugated systems which satisfy to a given symmetry with a Pariser-Parr-Pople-like (PPP) calculation are studied. Six π - electron systems are considered having a symmetry axis which does not cross π centers following a treatment which permits the direct obtainment of the bond order matrix based on Hall's method. Pairing relations are looked for, too, using particular solutions when U(3) groups is applied. Pyridazine molecules are used in order to test the results. (L.C.) [pt

  9. Modeling update for the Thirty Meter Telescope laser guide star dual-conjugate adaptive optics system

    Science.gov (United States)

    Gilles, Luc; Wang, Lianqi; Ellerbroek, Brent

    2010-07-01

    This paper describes the modeling efforts undertaken in the past couple of years to derive wavefront error (WFE) performance estimates for the Narrow Field Infrared Adaptive Optics System (NFIRAOS), which is the facility laser guide star (LGS) dual-conjugate adaptive optics (AO) system for the Thirty Meter Telescope (TMT). The estimates describe the expected performance of NFIRAOS as a function of seeing on Mauna Kea, zenith angle, and galactic latitude (GL). They have been developed through a combination of integrated AO simulations, side analyses, allocations, lab and lidar experiments.

  10. Cetuximab-conjugated nanodiamonds drug delivery system for enhanced targeting therapy and 3D Raman imaging.

    Science.gov (United States)

    Li, Dandan; Chen, Xin; Wang, Hong; Liu, Jie; Zheng, Meiling; Fu, Yang; Yu, Yuan; Zhi, Jinfang

    2017-12-01

    In this study, a multicomponent nanodiamonds (NDs)-based targeting drug delivery system, cetuximab-NDs-cisplatin bioconjugate, combining both specific targeting and enhanced therapeutic efficacy capabilities, is developed and characterized. The specific targeting ability of cetuximab-NDs-cisplatin system on human liver hepatocellular carcinoma (HepG2) cells is evaluated through epidermal growth factor receptor (EGFR) blocking experiments, since EGFR is over-expressed on HepG2 cell membrane. Besides, cytotoxic evaluation confirms that cetuximab-NDs-cisplatin system could significantly inhibit the growth of HepG2 cells, and the therapeutic activity of this system is proven to be better than that of both nonspecific NDs-cisplatin conjugate and specific EGF-NDs-cisplatin conjugate. Furthermore, a 3-dimensional (3D) Raman imaging technique is utilized to visualize the targeting efficacy and enhanced internalization of cetuximab-NDs-cisplatin system in HepG2 cells, using the NDs existing in the bioconjugate as Raman probes, based on the characteristic Raman signal of NDs at 1332 cm -1 . These advantageous properties of cetuximab-NDs-cisplatin system propose a prospective imaging and treatment tool for further diagnostic and therapeutic purposes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Coronary atherosclerosis: Significance of autophagic armour.

    Science.gov (United States)

    Arora, Mansi; Kaul, Deepak

    2012-09-26

    Autophagy is a lysosomal degradation pathway of cellular components such as organelles and long-lived proteins. Though a protective role for autophagy has been established in various patho-physiologic conditions such as cancer, neurodegeneration, aging and heart failure, a growing body of evidence now reveals a protective role for autophagy in atherosclerosis, mainly by removing oxidatively damaged organelles and proteins and also by promoting cholesterol egress from the lipid-laden cells. Recent studies by Razani et al and Liao et al unravel novel pathways that might be involved in autophagic protection and in this commentary we highlight the importance of autophagy in atherosclerosis in the light of these two recent papers.

  12. Preparation of ubiquitin-conjugated proteins using an insect cell-free protein synthesis system.

    Science.gov (United States)

    Suzuki, Takashi; Ezure, Toru; Ando, Eiji; Nishimura, Osamu; Utsumi, Toshihiko; Tsunasawa, Susumu

    2010-01-01

    Ubiquitination is one of the most significant posttranslational modifications (PTMs). To evaluate the ability of an insect cell-free protein synthesis system to carry out ubiquitin (Ub) conjugation to in vitro translated proteins, poly-Ub chain formation was studied in an insect cell-free protein synthesis system. Poly-Ub was generated in the presence of Ub aldehyde (UA), a de-ubiquitinating enzyme inhibitor. In vitro ubiquitination of the p53 tumor suppressor protein was also analyzed, and p53 was poly-ubiquitinated when Ub, UA, and Mdm2, an E3 Ub ligase (E3) for p53, were added to the in vitro reaction mixture. These results suggest that the insect cell-free protein synthesis system contains enzymatic activities capable of carrying out ubiquitination. CBB-detectable ubiquitinated p53 was easily purified from the insect cell-free protein synthesis system, allowing analysis of the Ub-conjugated proteins by mass spectrometry (MS). Lys 305 of p53 was identified as one of the Ub acceptor sites using this strategy. Thus, we conclude that the insect cell-free protein synthesis system is a powerful tool for studying various PTMs of eukaryotic proteins including ubiqutination presented here.

  13. Compensation of spatial system response in SPECT with conjugate gradient reconstruction technique

    International Nuclear Information System (INIS)

    Formiconi, A.R.; Pupi, A.; Passeri, A.

    1989-01-01

    A procedure for determination of the system matrix in single photon emission tomography (SPECT) is described which use a conjugate gradient reconstruction technique to take into account the variable system resolution of a camera equipped with parallel-hole collimators. The procedure involves acquisition of system line spread functions (LSF) in the region occupied by the object studied. Those data are used to generate a set of weighting factors based on the assumption that the LSFs of the collimated camera are of Gaussian shape with full width at half maximum (FWHM) linearly dependent on source depth in the span of image space. Factors are stored on a disc file for subsequent use in reconstruction. Afterwards reconstruction is performed using the conjugate gradient method with the system matrix modified by incorporation of these precalculated factors to take into account variable geometrical system response. The set of weighting factors is regenerated whenever acquisition conditions are changed (collimator, radius of rotation) with an ultra high resolution (UHR) collimator 2000 weighting factors need to be calculated. (author)

  14. Effect of temperature and ph on the drug release rate from a polymer conjugate system

    International Nuclear Information System (INIS)

    Kenawy, E.; Abdel-Hay, F.I.; El-Newehy, M.H.; Ottenbrite, R.M.

    2005-01-01

    Hydroximide and A-methylhydroxamic acid of poly(ethylene-altmaleic anhydride) (average MW 100-500 k) were used as a carrier for a new drug delivery system. The synthesis of the hydroximide and N methylhydroxamic acid of poly(ethylene-alt-maleic anhydride) were carried out by chemical modification of poly(ethylene-alt-maleic anhydride) with hydroxylamine and N-methyl hydroxylamine, respectively, in N,N- dimethylformamide at room temperature to yield water soluble copolymer. Ketoprofen was reacted with hydroximide and N-methylhydroxamic acid derivatives of poly(ethylene-alt-maleic anhydride) using dicyclohexylcarbodiimide as condensation agent at -5 degree C to yield water insoluble ketoprofen conjugates. All products were characterized by elemental analysis, FTIR and 1HNMR spectra. The in-vitro ketoprofen release was carried out by UV spectrophotometer at max =260 nm. The results demonstrated the effectiveness of hydroximide and N-methylhydroxamic acid of polyethylene-alt-maleic anhydride) as a drug delivery system. The release rates were studied at various ph and temperatures. The copolymer-drug adducts released the drug very slowly at the low ph found in the stomach thus protecting the drug from the action of high concentrations of digestive acids. These results showed the usefulness of hydroxamic acid polymer-drug conjugates as a new drug delivery system for drugs to be targeted to sites in the GI system

  15. Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

    Directory of Open Access Journals (Sweden)

    Clara Orofino-Pena

    2014-11-01

    Full Text Available Star-shaped conjugated systems with varying oligofluorene arm length and substitution patterns of the central BODIPY core have been synthesised, leading to two families of compounds, T-B1–T-B4 and Y-B1–Y-B4, with T- and Y-shaped motifs, respectively. Thermal stability, cyclic voltammetry, absorption and photoluminescence spectroscopy of each member of these two families were studied in order to determine their suitability as emissive materials in photonic applications.

  16. Theoretical investigation on structure and electronic properties of Si-bridged π-conjugated systems

    Science.gov (United States)

    Ohta, Eisuke; Ogaki, Takuya; Aoki, Toru; Oda, Yukiko; Matsui, Yasunori; Ikeda, Hiroshi

    2015-12-01

    Density functional theory calculations were performed on silylene-bridged cyclic tri- and tetrathienylenes, 1b and 2b, respectively. The results show that in comparison to their respective unbridged counterparts 1a and 2a, 1b and 2b have lower LUMO energies but similar reorganization energies for single electron transfer between 1b,2b and their respective radical anions 1b•-,2b•-. The observations suggest that silylene bridging of π-conjugated systems can serve as a novel strategy for designing materials of n-type organic semiconductor.

  17. Self-assembled systems of water soluble metal 8-hydroxyquinolates with surfactants and conjugated polyelectrolytes

    DEFF Research Database (Denmark)

    Burrows, Hugh D.; Costa, Telma; Luisa Ramos, M.

    2016-01-01

    We have studied the interaction of 8-hydroxyquinoline-5-sulfonate (8-HQS) with the metal ions Al(III) and Zn(II) in aqueous solution in the presence of tetraalkylammonium surfactants using UV/vis absorption, fluorescence, NMR spectroscopy and electrical conductivity measurements, complemented by ...... assembly between the conjugated polyelectrolyte and the metal/8-HQS complex, as demonstrated by electronic energy transfer. The potential of these systems in sensing, light harvesting, and electron injection/transport layers in organic semiconductor devices is discussed....

  18. Methods for assessing autophagy and autophagic cell death.

    Science.gov (United States)

    Tasdemir, Ezgi; Galluzzi, Lorenzo; Maiuri, M Chiara; Criollo, Alfredo; Vitale, Ilio; Hangen, Emilie; Modjtahedi, Nazanine; Kroemer, Guido

    2008-01-01

    Autophagic (or type 2) cell death is characterized by the massive accumulation of autophagic vacuoles (autophagosomes) in the cytoplasm of cells that lack signs of apoptosis (type 1 cell death). Here we detail and critically assess a series of methods to promote and inhibit autophagy via pharmacological and genetic manipulations. We also review the techniques currently available to detect autophagy, including transmission electron microscopy, half-life assessments of long-lived proteins, detection of LC3 maturation/aggregation, fluorescence microscopy, and colocalization of mitochondrion- or endoplasmic reticulum-specific markers with lysosomal proteins. Massive autophagic vacuolization may cause cellular stress and represent a frustrated attempt of adaptation. In this case, cell death occurs with (or in spite of) autophagy. When cell death occurs through autophagy, on the contrary, the inhibition of the autophagic process should prevent cellular demise. Accordingly, we describe a strategy for discriminating cell death with autophagy from cell death through autophagy.

  19. Some features of excited states density matrix calculation and their pairing relations in conjugated systems

    International Nuclear Information System (INIS)

    Giambiagi, M.S. de; Giambiagi, M.

    1982-01-01

    Direct PPP-type calculations of self-consistent (SC) density matrices for excited states are described and the corresponding 'thawn' molecular orbitals (MO) are discussed. Special attention is addressed to particular solutions arising in conjugated systems of a certain symmetry, and to their chemical implications. The U(2) and U(3) algebras are applied respectively to the 4-electron and 6-electron cases: a natural separation of excited states in different cases follows. A simple approach to the convergence problem for excited states is given. The complementarity relations, an alternative formulation of the pairing theorem valid for heteromolecules and non-alternant systems, allow some fruitful experimental applications. Together with the extended pairing relations shown here, they may help to rationalize general trends. (Author) [pt

  20. Systemic aspects of conjugal resilience in couples with a child facing cancer and marrow transplantation.

    Science.gov (United States)

    Martin, Julie; Péloquin, Katherine; Vachon, Marie-France; Duval, Michel; Sultan, Serge

    The negative impact of paediatric cancer on parents is well known and is even greater when intensive treatments are used. This study aimed to describe how couples whose child has received a transplant for the treatment of leukaemia view conjugal resilience and to evaluate the role of we-ness as a precursor of conjugal adjustment. Four parental couples were interviewed. Interviews were analysed in two ways: inductive thematic analysis and rating of verbal content with the We-ness Coding Scale . Participants report that conjugal resilience involves the identification of the couple as a team and cohesion in the couple. Being a team generates certain collaborative interactions that lead to conjugal resilience. A sense of we-ness in parents is associated with fluctuation in the frequency of themes. Participants' vision of conjugal resilience introduced novel themes. The sense of we-ness facilitates cohesion and the process of conjugal resilience.

  1. Systemic aspects of conjugal resilience in couples with a child facing cancer and marrow transplantation

    Directory of Open Access Journals (Sweden)

    Julie Martin

    2016-09-01

    Full Text Available Introduction: The negative impact of paediatric cancer on parents is well known and is even greater when intensive treatments are used. This study aimed to describe how couples whose child has received a transplant for the treatment of leukaemia view conjugal resilience and to evaluate the role of we-ness as a precursor of conjugal adjustment. Methods: Four parental couples were interviewed. Interviews were analysed in two ways: inductive thematic analysis and rating of verbal content with the We-ness Coding Scale. Results: Participants report that conjugal resilience involves the identification of the couple as a team and cohesion in the couple. Being a team generates certain collaborative interactions that lead to conjugal resilience. A sense of we-ness in parents is associated with fluctuation in the frequency of themes. Discussion: Participants’ vision of conjugal resilience introduced novel themes. The sense of we-ness facilitates cohesion and the process of conjugal resilience.

  2. Synthesis of nano-bio conjugates for drug delivery systems using gas-liquid interfacial discharge plasmas

    International Nuclear Information System (INIS)

    Kaneko, Toshiro; Chen, Qiang; Hatakeyama, Rikizo

    2012-01-01

    Size-controlled gold nanoparticles (AuNPs) covered with DNA are synthesized by using a pulse driven gas-liquid interfacial discharge plasma (GLIDP) to reduce an aqueous solution of chloroauric acid trihydrate with DNA. The size and the assembly of the AuNPs are found to be easily controlled by changing the DNA concentration in the aqueous solution. The synthesized AuNP-DNA conjugates are forced to be encapsulated into double-walled carbon nanotubes (DWNTs) by superimposing a positive DC voltage on the pulse voltage. The AuNP-DNA-conjugate encapsulated DWNTs can be utilized in drug delivery systems when DNA is used as a drug molecule.

  3. PEGylated Polyamidoamine dendrimer conjugated with tumor homing peptide as a potential targeted delivery system for glioma.

    Science.gov (United States)

    Jiang, Yan; Lv, Lingyan; Shi, Huihui; Hua, Yabing; Lv, Wei; Wang, Xiuzhen; Xin, Hongliang; Xu, Qunwei

    2016-11-01

    Glioblastoma multiforme (GBM) is the most common and aggressive primary central nervous system (CNS) tumor with a short survival time. The failure of chemotherapy is ascribed to the low transport of chemotherapeutics across the Blood Brain Tumor Barrier (BBTB) and poor penetration into tumor tissue. In order to overcome the two barriers, small nanoparticles with active targeted capability are urgently needed for GBM drug delivery. In this study, we proposed PEGylated Polyamidoamine (PAMAM) dendrimer nanoparticles conjugated with glioma homing peptides (Pep-1) as potential glioma targeting delivery system (Pep-PEG-PAMAM), where PEGylated PAMAM dendrimer nanoparticle was utilized as carrier due to its small size and perfect penetration into tumor and Pep-1 was used to overcome BBTB via interleukin 13 receptor α2 (IL-13Rα2) mediated endocytosis. The preliminary availability and safety of Pep-PEG-PAMAM as a nanocarrier for glioma was evaluated. In vitro results indicated that a significantly higher amount of Pep-PEG-PAMAM was endocytosed by U87 MG cells. In vivo fluorescence imaging of U87MG tumor-bearing mice confirmed that the fluorescence intensity at glioma site of targeted group was 2.02 folds higher than that of untargeted group (**p<0.01), and glioma distribution experiment further revealed that Pep-PEG-PAMAM exhibited a significantly enhanced accumulation and improved penetration at tumor site. In conclusion, Pep-1 modified PAMAM was a promising nanocarrier for targeted delivery of brain glioma. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Implementation of a conjugate gradient algorithm for thermal diffusivity identification in a moving boundaries system

    International Nuclear Information System (INIS)

    Perez, L; Autrique, L; Gillet, M

    2008-01-01

    The aim of this paper is to investigate the thermal diffusivity identification of a multilayered material dedicated to fire protection. In a military framework, fire protection needs to meet specific requirements, and operational protective systems must be constantly improved in order to keep up with the development of new weapons. In the specific domain of passive fire protections, intumescent coatings can be an effective solution on the battlefield. Intumescent materials have the ability to swell up when they are heated, building a thick multi-layered coating which provides efficient thermal insulation to the underlying material. Due to the heat aggressions (fire or explosion) leading to the intumescent phenomena, high temperatures are considered and prevent from linearization of the mathematical model describing the system state evolution. Previous sensitivity analysis has shown that the thermal diffusivity of the multilayered intumescent coating is a key parameter in order to validate the predictive numerical tool and therefore for thermal protection optimisation. A conjugate gradient method is implemented in order to minimise the quadratic cost function related to the error between predicted temperature and measured temperature. This regularisation algorithm is well adapted for a large number of unknown parameters.

  5. A modified conjugate gradient method based on the Tikhonov system for computerized tomography (CT).

    Science.gov (United States)

    Wang, Qi; Wang, Huaxiang

    2011-04-01

    During the past few decades, computerized tomography (CT) was widely used for non-destructive testing (NDT) and non-destructive examination (NDE) in the industrial area because of its characteristics of non-invasiveness and visibility. Recently, CT technology has been applied to multi-phase flow measurement. Using the principle of radiation attenuation measurements along different directions through the investigated object with a special reconstruction algorithm, cross-sectional information of the scanned object can be worked out. It is a typical inverse problem and has always been a challenge for its nonlinearity and ill-conditions. The Tikhonov regulation method is widely used for similar ill-posed problems. However, the conventional Tikhonov method does not provide reconstructions with qualities good enough, the relative errors between the reconstructed images and the real distribution should be further reduced. In this paper, a modified conjugate gradient (CG) method is applied to a Tikhonov system (MCGT method) for reconstructing CT images. The computational load is dominated by the number of independent measurements m, and a preconditioner is imported to lower the condition number of the Tikhonov system. Both simulation and experiment results indicate that the proposed method can reduce the computational time and improve the quality of image reconstruction. Copyright © 2010 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Systemic aspects of conjugal resilience in couples with a child facing cancer and marrow transplantation

    OpenAIRE

    Martin, Julie; P?loquin, Katherine; Vachon, Marie-France; Duval, Michel; Sultan, Serge

    2016-01-01

    Introduction: The negative impact of paediatric cancer on parents is well known and is even greater when intensive treatments are used. This study aimed to describe how couples whose child has received a transplant for the treatment of leukaemia view conjugal resilience and to evaluate the role of we-ness as a precursor of conjugal adjustment.Methods: Four parental couples were interviewed. Interviews were analysed in two ways: inductive thematic analysis and rating of verbal content with the...

  7. Routine Western blot to check autophagic flux : Cautions and recommendations

    NARCIS (Netherlands)

    Gomez-Sanchez, Ruben; Pizarro-Estrella, Elisa; Yakhine-Diop, Sokhna M. S.; Rodriguez-Arribas, Mario; Bravo-San Pedro, Jose M.; Fuentes, Jose M.; Gonzalez-Polo, Rosa A.

    2015-01-01

    At present, the analysis of autophagic flux by Western blotting (WB), which measures two of the most important markers of autophagy, i.e., microtubule-associated protein 1 light chain 3 (LC3) and p62, is widely accepted in the scientific community. In this study, we addressed the possible

  8. Highly lipophilic pluronics-conjugated polyamidoamine dendrimer nanocarriers as potential delivery system for hydrophobic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Thi Tram Chau [Institute of Research and Development, Duy Tan University, Da Nang City 550000 (Viet Nam); Department of Chemical Engineering, Industrial University of HCMC, HCMC 70000 (Viet Nam); Nguyen, Cuu Khoa, E-mail: nckhoavnn@yahoo.com [Department of Materials and Pharmaceutical Chemistry, Vietnam Academy of Science and Technology, HCMC 70000 (Viet Nam); Nguyen, Thi Hiep [Biomedical Engineering Department, International University, National Universities in HCMC, HCMC 70000 (Viet Nam); Tran, Ngoc Quyen, E-mail: tnquyen@iams.vast.vn [Institute of Research and Development, Duy Tan University, Da Nang City 550000 (Viet Nam); Department of Materials and Pharmaceutical Chemistry, Vietnam Academy of Science and Technology, HCMC 70000 (Viet Nam)

    2017-01-01

    In the study, four kinds of pluronics (P123, F68, F127 and F108) with varying hydrophilic-lipophilic balance (HLB) values were modified and conjugated on 4th generation of polyamidoamine dendrimer (PAMAM). The obtained results from FT-IR, {sup 1}H NMR and GPC showed that the pluronics effectively conjugated on the dendrimer. The molecular weight of four PAMAM G4.0-Pluronics and its morphologies are in range of 200.15–377.14 kDa and around 60–180 nm in diameter by TEM, respectively. Loading efficiency and release of hydrophobic fluorouracil (5-FU) anticancer drug were evaluated by HPLC; Interesting that the dendrimer nanocarrier was conjugated with the highly lipophilic pluronic P123 (G4.0-P123) exhibiting a higher drug loading efficiency (up to 76.25%) in comparison with another pluronics. Live/dead fibroblast cell staining assay mentioned that all conjugated nanocarriers are highly biocompatible. The drug-loaded nanocarriers also indicated a highly anti-proliferative activity against MCF-7 breast cancer cell. The obtained results demonstrated a great potential of the highly lipophilic pluronics-conjugated nanocarriers in hydrophobic drugs delivery for biomedical applications. - Highlights: • Biocompatible pluronic-conjugated polyamidoamine dendrimers were prepared at nanoscale for drug delivery. • The dendrimer nanocarrier was decorated with a lipophilic pluronic exhibiting a higher drug loading efficiency. • The pluronic-functionalized nanocarriers demonstrated a great potential for delivering hydrophobic drugs.

  9. A new modified conjugate gradient coefficient for solving system of linear equations

    Science.gov (United States)

    Hajar, N.; ‘Aini, N.; Shapiee, N.; Abidin, Z. Z.; Khadijah, W.; Rivaie, M.; Mamat, M.

    2017-09-01

    Conjugate gradient (CG) method is an evolution of computational method in solving unconstrained optimization problems. This approach is easy to implement due to its simplicity and has been proven to be effective in solving real-life application. Although this field has received copious amount of attentions in recent years, some of the new approaches of CG algorithm cannot surpass the efficiency of the previous versions. Therefore, in this paper, a new CG coefficient which retains the sufficient descent and global convergence properties of the original CG methods is proposed. This new CG is tested on a set of test functions under exact line search. Its performance is then compared to that of some of the well-known previous CG methods based on number of iterations and CPU time. The results show that the new CG algorithm has the best efficiency amongst all the methods tested. This paper also includes an application of the new CG algorithm for solving large system of linear equations

  10. The discovery of a conjugate system of faults in the Wharton Basin intraplate deformation zone.

    Science.gov (United States)

    Singh, Satish C; Hananto, Nugroho; Qin, Yanfang; Leclerc, Frederique; Avianto, Praditya; Tapponnier, Paul E; Carton, Helene; Wei, Shengji; Nugroho, Adam B; Gemilang, Wishnu A; Sieh, Kerry; Barbot, Sylvain

    2017-01-01

    The deformation at well-defined, narrow plate boundaries depends on the relative plate motion, but how the deformation takes place within a distributed plate boundary zone remains a conundrum. This was confirmed by the seismological analyses of the 2012 great Wharton Basin earthquakes [moment magnitude ( M w ) 8.6], which suggested the rupture of several faults at high angles to one another. Using high-resolution bathymetry and seismic reflection data, we report the discovery of new N294°E-striking shear zones, oblique to the plate fabric. These shear zones are expressed by sets of normal faults striking at N335°E, defining the direction of the principal compressional stress in the region. Also, we have imaged left-lateral strike-slip faults along reactivated N7°E-oriented oceanic fracture zones. The shear zones and the reactivated fracture zones form a conjugate system of faults, which accommodate present-day intraplate deformation in the Wharton Basin.

  11. Vectorization of agrochemicals: amino acid carriers are more efficient than sugar carriers to translocate phenylpyrrole conjugates in the Ricinus system.

    Science.gov (United States)

    Wu, Hanxiang; Marhadour, Sophie; Lei, Zhi-Wei; Yang, Wen; Marivingt-Mounir, Cécile; Bonnemain, Jean-Louis; Chollet, Jean-François

    2018-05-01

    Producing quality food in sufficient quantity while using less agrochemical inputs will be one of the great challenges of the twenty-first century. One way of achieving this goal is to greatly reduce the doses of plant protection compounds by improving the targeting of pests to eradicate. Therefore, we developed a vectorization strategy to confer phloem mobility to fenpiclonil, a contact fungicide from the phenylpyrrole family used as a model molecule. It consists in coupling the antifungal compound to an amino acid or a sugar, so that the resulting conjugates are handled by active nutrient transport systems. The method of click chemistry was used to synthesize three conjugates combining fenpiclonil to glucose or glutamic acid with a spacer containing a triazole ring. Systemicity tests with the Ricinus model have shown that the amino acid promoiety was clearly more favorable to phloem mobility than that of glucose. In addition, the transport of the amino acid conjugate is carrier mediated since the derivative of the L series was about five times more concentrated in the phloem sap than its counterpart of the D series. The systemicity of the L-derivative is pH dependent and almost completely inhibited by the protonophore carbonyl cyanide 3-chlorophenylhydrazone (CCCP). These data suggest that the phloem transport of the L-derivative is governed by a stereospecific amino acid carrier system energized by the proton motive force.

  12. Kekulé-based Valence Bond Model.I. The Ground-state Properties of Conjugated π-Systems

    Institute of Scientific and Technical Information of China (English)

    LI,Shu-Hua(黎书华); MA,Jing(马晶); JIANG,Yuan-Sheng(江元生)

    2002-01-01

    The Kekulé-based valence bond ( VB ) method, in which the VB model is solved using covalent Kekulé structures as basis functions, is justified in the present work. This method is dimonstrated to provide satisfactory descriptions for resoance energies and bond ang lengths of benzenoid hydrocarbons, being in good agreement with SCF-MO and experimental results. In additicn, an alternative way of discyssing characters of localizedsubstructures within a polyclic benzenoid system is suggested based upon such sunokufied VB calculations. Finally,the symmetries of VB ground states for nonalternant conjugated systems are also illustrated to be obtainable through these calculations, presenting very useful information for understanding the chemical behaviors of some nonalternant conjugated molecules.

  13. Integrin Targeting and Toxicological Assessment of Peptide-Conjugated Liposome Delivery Systems to Activated Endothelial Cells

    DEFF Research Database (Denmark)

    Kermanizadeh, Ali; Villadsen, Klaus; Østrem, Ragnhild Garborg

    2017-01-01

    constructed with the aim of targeting integrins (i.e. vitronectin and/or fibronectin receptors) on activated endothelial cells. The peptide-conjugated liposomes induced only cytotoxicity at the highest concentration in non-activated or activated endothelial cells, as well as in co-culture of endothelial cells...... and macrophages. There was unaltered secretion of cytokines following exposure of peptide-conjugated liposomes to endothelial cells, indicating that the materials were not inflammogenic. Liposomes with a peptide targeting the fibronectin receptor (integrin α5β1) were more effective in targeting of activated....... Therefore, this study demonstrates the feasibility of constructing a peptide-conjugated cationic liposome, which displays targeting to activated endothelial cells at concentrations that are not cytotoxic or inflammogenic to the cells....

  14. High-Resolution Spectroscopy of Jet-Cooled 1,1 '-Diphenylethylene: Electronically Excited and Ionic States of a Prototypical Cross-Conjugated System

    NARCIS (Netherlands)

    Smolarek, S.; Vdovin, A.; Rijs, A.; van Walree, C. A.; Zgierski, M. Z.; Buma, W. J.

    2011-01-01

    The photophysics of a prototypical cross-conjugated pi-system, 1,1'-diphenylethylene, have been studied using high-resolution resonance enhanced multiphoton ionization excitation spectroscopy and zero kinetic energy photoelectron spectroscopy, in combination with advanced ab initio

  15. Systemic and Mucosal Antibody Responses to Soluble and Nanoparticle-Conjugated Antigens Administered Intranasally

    Directory of Open Access Journals (Sweden)

    Savannah E. Howe

    2016-10-01

    Full Text Available Nanoparticles (NPs are increasingly being used for drug delivery, as well as antigen carriers and immunostimulants for the purpose of developing vaccines. In this work, we examined how intranasal (i.n. priming followed by i.n. or subcutaneous (s.c. boosting immunization affects the humoral immune response to chicken ovalbumin (Ova and Ova conjugated to 20 nm NPs (NP-Ova. We show that i.n. priming with 20 mg of soluble Ova, a dose known to trigger oral tolerance when administered via gastric gavage, induced substantial systemic IgG1 and IgG2c, as well as mucosal antibodies. These responses were further boosted following a s.c. immunization with Ova and complete Freund’s adjuvant (Ova+CFA. In contrast, 100 µg of Ova delivered via NPs induced an IgG1-dominated systemic response, and primed the intestinal mucosa for secretion of IgA. Following a secondary s.c. or i.n. immunization with Ova+CFA or NP-Ova, systemic IgG1 titers significantly increased, and serum IgG2c and intestinal antibodies were induced in mice primed nasally with NP-Ova. Only Ova- and NP-Ova-primed mice that were s.c.-boosted exhibited substantial systemic and mucosal titers for up to 6 months after priming, whereas the antibodies of i.n.-boosted mice declined over time. Our results indicate that although the amount of Ova delivered by NPs was 1000-fold less than Ova delivered in soluble form, the antigen-specific antibody responses, both systemic and mucosal, are essentially identical by 6 months following the initial priming immunization. Additionally, both i.n.- and s.c.-boosting strategies for NP-Ova-primed mice were capable of inducing a polarized Th1/Th2 immune response, as well as intestinal antibodies; however, it is only by using a heterogeneous prime-boost strategy that long-lasting antibody responses were initiated. These results provide valuable insight for future mucosal vaccine development, as well as furthering our understanding of mucosal antibody responses.

  16. Autophagic components contribute to hypersensitive cell death in Arabidopsis

    DEFF Research Database (Denmark)

    Hofius, Daniel; Schultz-Larsen, Torsten; Joensen, Jan

    2009-01-01

    Autophagy has been implicated as a prosurvival mechanism to restrict programmed cell death (PCD) associated with the pathogen-triggered hypersensitive response (HR) during plant innate immunity. This model is based on the observation that HR lesions spread in plants with reduced autophagy gene...... expression. Here, we examined receptor-mediated HR PCD responses in autophagy-deficient Arabidopsis knockout mutants (atg), and show that infection-induced lesions are contained in atg mutants. We also provide evidence that HR cell death initiated via Toll/Interleukin-1 (TIR)-type immune receptors through...... the defense regulator EDS1 is suppressed in atg mutants. Furthermore, we demonstrate that PCD triggered by coiled-coil (CC)-type immune receptors via NDR1 is either autophagy-independent or engages autophagic components with cathepsins and other unidentified cell death mediators. Thus, autophagic cell death...

  17. Autophagic machinery activated by dengue virus enhances virus replication

    International Nuclear Information System (INIS)

    Lee, Y.-R.; Lei, H.-Y.; Liu, M.-T.; Wang, J.-R.; Chen, S.-H.; Jiang-Shieh, Y.-F.; Lin, Y.-S.; Yeh, T.-M.; Liu, C.-C.; Liu, H.-S.

    2008-01-01

    Autophagy is a cellular response against stresses which include the infection of viruses and bacteria. We unravel that Dengue virus-2 (DV2) can trigger autophagic process in various infected cell lines demonstrated by GFP-LC3 dot formation and increased LC3-II formation. Autophagosome formation was also observed under the transmission electron microscope. DV2-induced autophagy further enhances the titers of extracellular and intracellular viruses indicating that autophagy can promote viral replication in the infected cells. Moreover, our data show that ATG5 protein is required to execute DV2-induced autophagy. All together, we are the first to demonstrate that DV can activate autophagic machinery that is favorable for viral replication

  18. Curcumin induces autophagic cell death in Spodoptera frugiperda cells.

    Science.gov (United States)

    Veeran, Sethuraman; Shu, Benshui; Cui, Gaofeng; Fu, Shengjiao; Zhong, Guohua

    2017-06-01

    The increasing interest in the role of autophagy (type II cell death) in the regulation of insect toxicology has propelled study of investigating autophagic cell death pathways. Turmeric, the rhizome of the herb Curcuma longa (Mañjaḷ in Tamil, India and Jiānghuáng in Chinese) have been traditionally used for the pest control either alone or combination with other botanical pesticides. However, the mechanisms by which Curcuma longa or curcumin exerts cytotoxicity in pests are not well understood. In this study, we investigated the potency of Curcuma longa (curcumin) as a natural pesticide employing Sf9 insect line. Autophagy induction effect of curcumin on Spodoptera frugiperda (Sf9) cells was investigated using various techniques including cell proliferation assay, morphology analysis with inverted phase contrast microscope and Transmission Electron Microscope (TEM) analysis. Autophagy was evaluated using the fluorescent dye monodansylcadaverine (MDC). Cell death measurement was examined using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) within the concentrations of 5-15μg/mL. Curcumin inhibited the growth of the Sf9 cells and induced autophagic cell death in a time and dose dependent manner. Staining the cells with MDC showed the presence of autophagic vacuoles while increased in a dose and time dependent manner. At the ultrastructural level transmission electron microscopy, cells revealed massive autophagy vacuole accumulation and absence of chromatin condensation. Protein expression levels of ATG8-I and ATG8-II, well-established markers of autophagy related protein were elevated in a time dependent manner after curcumin treatment. The present study proves that curcumin induces autophagic cell death in Sf9 insect cell line and this is the first report of cytotoxic effect of curcumin in insect cells and that will be utilized as natural pesticides in future. Copyright © 2017. Published by Elsevier Inc.

  19. Spastic paraplegia proteins spastizin and spatacsin mediate autophagic lysosome reformation

    OpenAIRE

    Chang, Jaerak; Lee, Seongju; Blackstone, Craig

    2014-01-01

    Autophagy allows cells to adapt to changes in their environment by coordinating the degradation and recycling of cellular components and organelles to maintain homeostasis. Lysosomes are organelles critical for terminating autophagy via their fusion with mature autophagosomes to generate autolysosomes that degrade autophagic materials; therefore, maintenance of the lysosomal population is essential for autophagy-dependent cellular clearance. Here, we have demonstrated that the two most common...

  20. Treatment with belimumab in systemic lupus erythematosus does not impair antibody response to 13-valent pneumococcal conjugate vaccine.

    Science.gov (United States)

    Nagel, J; Saxne, T; Geborek, P; Bengtsson, A A; Jacobsen, S; Svaerke Joergensen, C; Nilsson, J-Å; Skattum, L; Jönsen, A; Kapetanovic, M C

    2017-09-01

    Background/purpose The objective of this study was to explore the impact of systemic lupus erythematosus and belimumab given in addition to standard of care therapy on 13-valent conjugated pneumococcal vaccine (PCV13) response. Methods Forty-seven systemic lupus erythematosus patients and 21 healthy controls were immunized with a single dose of 13-valent conjugated pneumococcal vaccine. Forty systemic lupus erythematosus patients were treated with traditional disease-modifying anti rheumatic drugs, 11 of those received belimumab in addition, and 32 patients were treated with concomitant prednisolone. Quantification of serotype specific IgG levels to 12 pneumococcal capsular polysaccharides was performed in serum taken before and four to six weeks after vaccination using multiplex fluorescent microsphere immunoassay. IgG levels against serotypes 23F and 6B were also analyzed using standard enzyme-linked immunosorbent assays. Opsonophagocytic assay was performed on serotype 23F to evaluate the functionality of the antibodies. Pre- and post-vaccination log transformed antibody levels were compared to determine the impact of systemic lupus erythematosus diagnosis and different treatments on antibody response. Results Systemic lupus erythematosus patients as a group showed lower post-vaccination antibody levels and lower fold increase of antibody levels after vaccination compared to controls ( p = 0.02 and p = 0.009, respectively). Systemic lupus erythematosus patients treated with belimumab in addition to standard of care therapy or with only hydroxychloroquine did not differ compared to controls, whereas the other treatment groups had significantly lower fold increase of post-vaccination antibody levels. Higher age was associated with lower post-vaccination antibody levels among systemic lupus erythematosus patients. Conclusion Belimumab given in addition to traditional disease-modifying anti rheumatic drugs or prednisolone did not further impair antibody

  1. Doxorubicin Blocks Cardiomyocyte Autophagic Flux by Inhibiting Lysosome Acidification.

    Science.gov (United States)

    Li, Dan L; Wang, Zhao V; Ding, Guanqiao; Tan, Wei; Luo, Xiang; Criollo, Alfredo; Xie, Min; Jiang, Nan; May, Herman; Kyrychenko, Viktoriia; Schneider, Jay W; Gillette, Thomas G; Hill, Joseph A

    2016-04-26

    The clinical use of doxorubicin is limited by cardiotoxicity. Histopathological changes include interstitial myocardial fibrosis and the appearance of vacuolated cardiomyocytes. Whereas dysregulation of autophagy in the myocardium has been implicated in a variety of cardiovascular diseases, the role of autophagy in doxorubicin cardiomyopathy remains poorly defined. Most models of doxorubicin cardiotoxicity involve intraperitoneal injection of high-dose drug, which elicits lethargy, anorexia, weight loss, and peritoneal fibrosis, all of which confound the interpretation of autophagy. Given this, we first established a model that provokes modest and progressive cardiotoxicity without constitutional symptoms, reminiscent of the effects seen in patients. We report that doxorubicin blocks cardiomyocyte autophagic flux in vivo and in cardiomyocytes in culture. This block was accompanied by robust accumulation of undegraded autolysosomes. We go on to localize the site of block as a defect in lysosome acidification. To test the functional relevance of doxorubicin-triggered autolysosome accumulation, we studied animals with diminished autophagic activity resulting from haploinsufficiency for Beclin 1. Beclin 1(+/-) mice exposed to doxorubicin were protected in terms of structural and functional changes within the myocardium. Conversely, animals overexpressing Beclin 1 manifested an amplified cardiotoxic response. Doxorubicin blocks autophagic flux in cardiomyocytes by impairing lysosome acidification and lysosomal function. Reducing autophagy initiation protects against doxorubicin cardiotoxicity. © 2016 American Heart Association, Inc.

  2. Vectorisation of agrochemicals via amino acid carriers: influence of the spacer arm structure on the phloem mobility of phenylpyrrole conjugates in the Ricinus system.

    Science.gov (United States)

    Marhadour, Sophie; Wu, Hanxiang; Yang, Wen; Marivingt-Mounir, Cécile; Bonnemain, Jean-Louis; Chollet, Jean-François

    2017-09-01

    Excessive agrochemical use poses significant threats to environmental safety and human health. Reducing pesticide use without reducing yield is necessary for sustainable agriculture. Therefore, we developed a vectorisation strategy to enhance agrochemical delivery through plant amino acid carriers. In addition to a fenpiclonil conjugate recently described, three new amino acid conjugates were synthesised by coupling fenpiclonil to an l-α-amino acid. Phloem mobility of these conjugates, which exhibit different structures of the spacer arm introduced between fenpiclonil and the α-amino acid function, was studied using the Ricinus model. Conjugate L-14, which contains a triazole ring with the shortest amino acid chain, showed the best phloem systemicity among the four conjugates. By contrast, removing the triazole ring in the spacer arm did not improve systemicity. L-14 exhibited phloem systemicity at all reported pH values (pH values from 5.0 to 6.5) of the foliar apoplast, while acidic derivatives of fenpiclonil were translocated only at pH values near 5.0. The conjugates were recognised by a pH-dependent transporter system and translocated at distance in the phloem. They exhibited a broader phloem systemicity than fenpiclonil acidic derivatives within the pH value range of the foliar apoplast. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Supramolecular dendritic pi-conjugated systems: synthesis of glycinylurea functionalized pi-conjugated diphenylanthracene guests and their complexation with dendritic hosts. Part I.

    NARCIS (Netherlands)

    Precup, F.S.; Schenning, A.P.H.J.; Meijer, E.W.; Hubca, G.

    2007-01-01

    Glycinylurea functionalized p-conjugated diphenylanthracene guests (DPA guests) that bind to adamantyl urea modified dendritic hosts were synthesized and fully characterized by NMR spectroscopy (1H-NMR, 13C-NMR) and MALDI-TOF-MS. The resulting supramolecular assemblies have been investigated with

  4. Seismic Evidence for Conjugate Slip and Block Rotation Within the San Andreas Fault System, Southern California

    Science.gov (United States)

    Nicholson, Craig; Seeber, Leonardo; Williams, Patrick; Sykes, Lynn R.

    1986-08-01

    The pattern of seismicity in southern California indicates that much of the activity is presently occurring on secondary structures, several of which are oriented nearly orthogonal to the strikes of the major through-going faults. Slip along these secondary transverse features is predominantly left-lateral and is consistent with the reactivation of conjugate faults by the current regional stress field. Near the intersection of the San Jacinto and San Andreas faults, however, these active left-lateral faults appear to define a set of small crustal blocks, which in conjunction with both normal and reverse faulting earthquakes, suggests contemporary clockwise rotation as a result of regional right-lateral shear. Other left-lateral faults representing additional rotating block systems are identified in adjacent areas from geologic and seismologic data. Many of these structures predate the modern San Andreas system and may control the pattern of strain accumulation in southern California. Geodetic and paleomagnetic evidence confirm that block rotation by strike-slip faulting is nearly ubiquitous, particularly in areas where shear is distributed, and that it accommodates both short-term elastic and long-term nonelastic strain. A rotating block model accounts for a number of structural styles characteristic of strike-slip deformation in California, including: variable slip rates and alternating transtensional and transpressional features observed along strike of major wrench faults; domains of evenly-spaced antithetic faults that terminate against major fault boundaries; continued development of bends in faults with large lateral displacements; anomalous focal mechanisms; and differential uplift in areas otherwise expected to experience extension and subsidence. Since block rotation requires a detachment surface at depth to permit rotational movement, low-angle structures like detachments, of either local or regional extent, may be involved in the contemporary strike

  5. The different roles of selective autophagic protein degradation in mammalian cells.

    Science.gov (United States)

    Wang, Da-wei; Peng, Zhen-ju; Ren, Guang-fang; Wang, Guang-xin

    2015-11-10

    Autophagy is an intracellular pathway for bulk protein degradation and the removal of damaged organelles by lysosomes. Autophagy was previously thought to be unselective; however, studies have increasingly confirmed that autophagy-mediated protein degradation is highly regulated. Abnormal autophagic protein degradation has been associated with multiple human diseases such as cancer, neurological disability and cardiovascular disease; therefore, further elucidation of protein degradation by autophagy may be beneficial for protein-based clinical therapies. Macroautophagy and chaperone-mediated autophagy (CMA) can both participate in selective protein degradation in mammalian cells, but the process is quite different in each case. Here, we summarize the various types of macroautophagy and CMA involved in determining protein degradation. For this summary, we divide the autophagic protein degradation pathways into four categories: the post-translational modification dependent and independent CMA pathways and the ubiquitin dependent and independent macroautophagy pathways, and describe how some non-canonical pathways and modifications such as phosphorylation, acetylation and arginylation can influence protein degradation by the autophagy lysosome system (ALS). Finally, we comment on why autophagy can serve as either diagnostics or therapeutic targets in different human diseases.

  6. Hepatic steatosis inhibits autophagic proteolysis via impairment of autophagosomal acidification and cathepsin expression

    International Nuclear Information System (INIS)

    Inami, Yoshihiro; Yamashina, Shunhei; Izumi, Kousuke; Ueno, Takashi; Tanida, Isei; Ikejima, Kenichi; Watanabe, Sumio

    2011-01-01

    Highlights: → Acidification of autophagosome was blunted in steatotic hepatocytes. → Hepatic steatosis did not disturb fusion of isolated autophagosome and lysosome. → Proteinase activity of cathepsin B and L in autolysosomes was inhibited by steatosis. → Hepatic expression of cathepsin B and L was suppressed by steatosis. -- Abstract: Autophagy, one of protein degradation system, contributes to maintain cellular homeostasis and cell defense. Recently, some evidences indicated that autophagy and lipid metabolism are interrelated. Here, we demonstrate that hepatic steatosis impairs autophagic proteolysis. Though accumulation of autophagosome is observed in hepatocytes from ob/ob mice, expression of p62 was augmented in liver from ob/ob mice more than control mice. Moreover, degradation of the long-lived protein leucine was significantly suppressed in hepatocytes isolated from ob/ob mice. More than 80% of autophagosomes were stained by LysoTracker Red (LTR) in hepatocytes from control mice; however, rate of LTR-stained autophagosomes in hepatocytes were suppressed in ob/ob mice. On the other hand, clearance of autolysosomes loaded with LTR was blunted in hepatocytes from ob/ob mice. Although fusion of isolated autophagosome and lysosome was not disturbed, proteinase activity of cathepsin B and L in autolysosomes and cathepsin B and L expression of liver were suppressed in ob/ob mice. These results indicate that lipid accumulation blunts autophagic proteolysis via impairment of autophagosomal acidification and cathepsin expression.

  7. Hepatic steatosis inhibits autophagic proteolysis via impairment of autophagosomal acidification and cathepsin expression

    Energy Technology Data Exchange (ETDEWEB)

    Inami, Yoshihiro [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Yamashina, Shunhei, E-mail: syamashi@juntendo.ac.jp [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Izumi, Kousuke [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Ueno, Takashi [Department of Biochemistry, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Tanida, Isei [Department of Biochemistry and Cell Biology, Laboratory of Biomembranes, National Institute of Infectious Disease, Toyama 1-23-1, Shinjuku-ku, Tokyo 162-8640 (Japan); Ikejima, Kenichi; Watanabe, Sumio [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2011-09-09

    Highlights: {yields} Acidification of autophagosome was blunted in steatotic hepatocytes. {yields} Hepatic steatosis did not disturb fusion of isolated autophagosome and lysosome. {yields} Proteinase activity of cathepsin B and L in autolysosomes was inhibited by steatosis. {yields} Hepatic expression of cathepsin B and L was suppressed by steatosis. -- Abstract: Autophagy, one of protein degradation system, contributes to maintain cellular homeostasis and cell defense. Recently, some evidences indicated that autophagy and lipid metabolism are interrelated. Here, we demonstrate that hepatic steatosis impairs autophagic proteolysis. Though accumulation of autophagosome is observed in hepatocytes from ob/ob mice, expression of p62 was augmented in liver from ob/ob mice more than control mice. Moreover, degradation of the long-lived protein leucine was significantly suppressed in hepatocytes isolated from ob/ob mice. More than 80% of autophagosomes were stained by LysoTracker Red (LTR) in hepatocytes from control mice; however, rate of LTR-stained autophagosomes in hepatocytes were suppressed in ob/ob mice. On the other hand, clearance of autolysosomes loaded with LTR was blunted in hepatocytes from ob/ob mice. Although fusion of isolated autophagosome and lysosome was not disturbed, proteinase activity of cathepsin B and L in autolysosomes and cathepsin B and L expression of liver were suppressed in ob/ob mice. These results indicate that lipid accumulation blunts autophagic proteolysis via impairment of autophagosomal acidification and cathepsin expression.

  8. Interplay of pathogenic forms of human tau with different autophagic pathways.

    Science.gov (United States)

    Caballero, Benjamin; Wang, Yipeng; Diaz, Antonio; Tasset, Inmaculada; Juste, Yves Robert; Stiller, Barbara; Mandelkow, Eva-Maria; Mandelkow, Eckhard; Cuervo, Ana Maria

    2018-02-01

    Loss of neuronal proteostasis, a common feature of the aging brain, is accelerated in neurodegenerative disorders, including different types of tauopathies. Aberrant turnover of tau, a microtubule-stabilizing protein, contributes to its accumulation and subsequent toxicity in tauopathy patients' brains. A direct toxic effect of pathogenic forms of tau on the proteolytic systems that normally contribute to their turnover has been proposed. In this study, we analyzed the contribution of three different types of autophagy, macroautophagy, chaperone-mediated autophagy, and endosomal microautophagy to the degradation of tau protein variants and tau mutations associated with this age-related disease. We have found that the pathogenic P301L mutation inhibits degradation of tau by any of the three autophagic pathways, whereas the risk-associated tau mutation A152T reroutes tau for degradation through a different autophagy pathway. We also found defective autophagic degradation of tau when using mutations that mimic common posttranslational modifications in tau or known to promote its aggregation. Interestingly, although most mutations markedly reduced degradation of tau through autophagy, the step of this process preferentially affected varies depending on the type of tau mutation. Overall, our studies unveil a complex interplay between the multiple modifications of tau and selective forms of autophagy that may determine its physiological degradation and its faulty clearance in the disease context. © 2017 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  9. Peptides, proteins and peptide/protein-polymer conjugates as drug delivery system.

    Science.gov (United States)

    Mukherjee, Biswajit; Karmakar, Swapna D; Hossain, Chowdhury M; Bhattacharya, Sanchari

    2014-01-01

    In the last few decades, novel drug delivery strategies have been a big priority to the formulation scientists. Peptides and proteins have drawn a special attention for their wide scope in the area. Serum albumin, transferrin, recom- binant proteins, virus capsids etc. are used as carrier for drug and biomolecules. Conjugates of polymers with proteins have also shown strong potency in the field of drug delivery. Polyethylene glycol is one of the most successful polymers that has been used extensively to develop protein conjugated formulations. Besides, polyvinyl pyrrolidone, polylactic-co- glycolic acid, N-(2-hydroxypropyl) methacrylamide copolymer, polyglutamic acid have also been investigated. In this re- view, we will highlight on the most recent overview of various advantages, limitations and marketed products of proteins, peptides and protein/peptide-polymer conjugates as drug carriers, such products in clinical trials and their various uses in the field of modern drug delivery. Understanding the key features of these materials and the vigorous research in this field will develop new drug formulations that will combat various types of life-threatening diseases.

  10. Patterns of Cs-137 and Sr-90 distribution in conjugated landscape systems

    Science.gov (United States)

    Korobova, E.

    2012-04-01

    The main goal of the study was to reveal spatial patterns of 137Cs and 90Sr distribution in soils and plants of conjugated landscapes and to use 137Cs as a tracer for natural migration and accumulation processes in the environment. The studies were based on presumptions that: 1) the environment consisted of interrelated bio- and geochemical fields of hierarchical structure depending on the level and age of factors responsible for spatial distribution of chemical elements; 2)distribution of technogenic radionuclides in natural landscapes depended upon the location and type of the initial source and radionuclide involvement in natural pathways controlled by the state and mobility of the typomorphic elements and water migration. Case studies were undertaken in areas subjected to contamination after the Chernobyl accident and in the estuary zones of the Yenisey and Pechora rivers. First observations in the Chernobyl remote zone in 1987-1989 demonstrated relation between the dose rate, 137Cs, 134Cs, 144Ce, 106Ru, 125Sb in soil cover and the location of the measured plot in landscape toposequence. Later study of 137Cs and 90Sr concentration and speciation confirmed different patterns of their distribution dependent upon the radioisotope, soil features and vegetation cover corresponding to the local landscape and landuse structure. Certain patterns in distribution and migration of 137Cs and 90Sr in soils and local food chain were followed in private farms situated in different landscape position [1]. Detailed study of 137Cs activity in forested site with a pronounced relief 20 and 25 years after the Chernobyl accident showed its stable polycentric structure in soils, mosses and litter which was sensitive to meso- and micro-relief features [2]. Radionuclide contamination of the lower Yenisey and Pechora studied along meridian landscape transects proved both areas be subjected to global 137Cs pollution while the Yenisey floodplain received additional regional contamination

  11. Modifications of Steepest Descent Method and Conjugate Gradient Method Against Noise for Ill-posed Linear Systems

    Directory of Open Access Journals (Sweden)

    Chein-Shan Liu

    2012-04-01

    Full Text Available It is well known that the numerical algorithms of the steepest descent method (SDM, and the conjugate gradient method (CGM are effective for solving well-posed linear systems. However, they are vulnerable to noisy disturbance for solving ill-posed linear systems. We propose the modifications of SDM and CGM, namely the modified steepest descent method (MSDM, and the modified conjugate gradient method (MCGM. The starting point is an invariant manifold defined in terms of a minimum functional and a fictitious time-like variable; however, in the final stage we can derive a purely iterative algorithm including an acceleration parameter. Through the Hopf bifurcation, this parameter indeed plays a major role to switch the situation of slow convergence to a new situation that the functional is stepwisely decreased very fast. Several numerical examples are examined and compared with exact solutions, revealing that the new algorithms of MSDM and MCGM have good computational efficiency and accuracy, even for the highly ill-conditioned linear equations system with a large noise being imposed on the given data.

  12. A glutathione conjugate of hepoxilin A3: Formation and action in the rat central nervous system

    International Nuclear Information System (INIS)

    Pace-Asciak, C.R.; Laneuville, O.; Su, W.G.; Corey, E.J.; Gurevich, N.; Wu, P.; Carlen, P.L.

    1990-01-01

    Incubation of (8R)- and (8S)-[1-14C]hepoxilin A3 [where hepoxilin A3 is 8-hydroxy-11,12-epoxyeicosa-(5Z,9E,14Z)-trienoic acid] and glutathione with homogenates of rat brain hippocampus resulted in a product that was identified as the (8R) and (8S) diastereomers of 11-glutathionyl hepoxilin A3 by reversed-phase high performance liquid chromatographic comparison with the authentic standard made by total synthesis. Identity was further confirmed by cleavage of the isolated product with gamma-glutamyltranspeptidase to yield the corresponding cysteinylglycinyl conjugate that was identical by reversed-phase high performance liquid chromatographic analysis with the enzymic cleavage product derived from the synthetic glutathionyl conjugate. The glutathionyl and cysteinylglycinyl conjugate are referred to as hepoxilin A3-C and hepoxilin A3-D, respectively, by analogy with the established leukotriene nomenclature. Formation of hepoxilin A3-C was greatly enhanced with a concomitant decrease in formation of the epoxide hydrolase product, trioxilin A3, when the epoxide hydrolase inhibitor trichloropropene oxide was added to the incubation mixture demonstrating the presence of a dual metabolic pathway in this tissue involving hepoxilin epoxide hydrolase and glutathione S-transferase processes. Hepoxilin A3-C was tested using intracellular electrophysiological techniques on hippocampal CA1 neurons and found to be active at concentrations as low as 16 nM in causing membrane hyperpolarization, enhanced amplitude and duration of the post-spike train afterhyperpolarization, a marked increase in the inhibitory postsynaptic potential, and a decrease in the spike threshold. These findings suggest that these products in the hepoxilin pathway of arachidonic acid metabolism formed by the rat brain may function as neuromodulators

  13. Operations of the External Conjugate-T Matching System for the A2 ICRH Antennas at JET

    International Nuclear Information System (INIS)

    Monakhov, I.; Graham, M.; Blackman, T.; Mayoral, M.-L.; Nightingale, M.; Sheikh, H.; Whitehurst, A.

    2009-01-01

    The External Conjugate-T (ECT) matching system was successfully commissioned on two A2 ICRH antennas at JET in 2009. The system allows trip-free injection of RF power into ELMy H-mode plasmas in the 32-52 MHz band without antenna phasing restrictions. The ECT demonstrates robust and predictable performance and high load-tolerance during routine operations, injecting up to 4 MW average power into H-mode plasma with Type-I ELMs. The total power coupled to ELMy plasma by all the A2 antennas using the ECT and 3dB systems has been increased to 7 MW. Antenna arcing during ELMs has been identified as a new challenge to high-power ICRH operations in H-mode plasma. The implemented Advanced Wave Amplitude Comparison System (AWACS) has proven to be an efficient protection tool for the ECT scheme.

  14. Development of a reduction-sensitive diselenide-conjugated oligoethylenimine nanoparticulate system as a gene carrier

    Directory of Open Access Journals (Sweden)

    Cheng G

    2012-07-01

    Full Text Available Gang Cheng,1,2 Yiyan He,1 Li Xie,1 Yu Nie,1 Bin He,1 Zhirong Zhang,2 Zhongwei Gu11National Engineering Research Center for Biomaterials, 2Key Laboratory of Drug Targeting and Drug Delivery Systems, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, People's Republic of ChinaBackground: The reduction-sensitive cationic polymer is a promising nonviral carrier for gene delivery. Until now, disulfide bonds have been the only golden standard for its design. The aim of this research was to develop a novel reduction-responsive cationic polymer as a gene carrier.Methods: Polycationic carriers were synthesized by addition of branched oligoethylenimine 800 Da (OEI800 via an active ester containing diselenide bonds. Disulfide bonds cross-linked with OEI800-SSx and monoselenide bonds linked with OEI800-Sex were synthesized and compared. Their molecular weights and degradation properties were determined using gel permeation chromatography. Changes in particle size, morphology, and DNA binding were investigated by dynamic light scattering, transmission electron microscopy, and electrophoresis assay in a reduction environment. Cytotoxicity and transfection in vitro were evaluated in a murine melanoma cell line (B16F10 and a human cervical epithelial carcinoma cell line (HeLa, while intracellular degradation and dissociation with DNA were studied by confocal laser scanning microscopy with FITC-labeled OEI800 derivatives and Cy5-labeled DNA.Results: Diselenide-conjugated OEI800 (OEI800-Se Sex polymer carriers of high molecular weight were successfully synthesized. After compacting with DNA, the OEI800-SeSex polymers formed nanoparticles with an average size of 140 nm at an adequate C/P ratio. OEI800-Se Sex showed reduction-responsive degradation properties similar to those of the OEI800-SSx via gel permeation chromatography, dynamic light scattering, and transmission electron microscopy. OEI800-SeSex showed much lower cytotoxicity than PEI25k

  15. Quantitative Analysis of Subcellular Distribution of the SUMO Conjugation System by Confocal Microscopy Imaging.

    Science.gov (United States)

    Mas, Abraham; Amenós, Montse; Lois, L Maria

    2016-01-01

    Different studies point to an enrichment in SUMO conjugation in the cell nucleus, although non-nuclear SUMO targets also exist. In general, the study of subcellular localization of proteins is essential for understanding their function within a cell. Fluorescence microscopy is a powerful tool for studying subcellular protein partitioning in living cells, since fluorescent proteins can be fused to proteins of interest to determine their localization. Subcellular distribution of proteins can be influenced by binding to other biomolecules and by posttranslational modifications. Sometimes these changes affect only a portion of the protein pool or have a partial effect, and a quantitative evaluation of fluorescence images is required to identify protein redistribution among subcellular compartments. In order to obtain accurate data about the relative subcellular distribution of SUMO conjugation machinery members, and to identify the molecular determinants involved in their localization, we have applied quantitative confocal microscopy imaging. In this chapter, we will describe the fluorescent protein fusions used in these experiments, and how to measure, evaluate, and compare average fluorescence intensities in cellular compartments by image-based analysis. We show the distribution of some components of the Arabidopsis SUMOylation machinery in epidermal onion cells and how they change their distribution in the presence of interacting partners or even when its activity is affected.

  16. Monitoring the introduction of pneumococcal conjugate vaccines into West Africa: design and implementation of a population-based surveillance system.

    Directory of Open Access Journals (Sweden)

    Grant A Mackenzie

    2012-01-01

    Full Text Available Routine use of pneumococcal conjugate vaccines (PCVs in developing countries is expected to lead to a significant reduction in childhood deaths. However, PCVs have been associated with replacement disease with non-vaccine serotypes. We established a population-based surveillance system to document the direct and indirect impact of PCVs on the incidence of invasive pneumococcal disease (IPD and radiological pneumonia in those aged 2 months and older in The Gambia, and to monitor changes in serotype-specific IPD. Here we describe how this surveillance system was set up and is being operated as a partnership between the Medical Research Council Unit and the Gambian Government. This surveillance system is expected to provide crucial information for immunisation policy and serves as a potential model for those introducing routine PCV vaccination in diverse settings.

  17. Spastic paraplegia proteins spastizin and spatacsin mediate autophagic lysosome reformation.

    Science.gov (United States)

    Chang, Jaerak; Lee, Seongju; Blackstone, Craig

    2014-12-01

    Autophagy allows cells to adapt to changes in their environment by coordinating the degradation and recycling of cellular components and organelles to maintain homeostasis. Lysosomes are organelles critical for terminating autophagy via their fusion with mature autophagosomes to generate autolysosomes that degrade autophagic materials; therefore, maintenance of the lysosomal population is essential for autophagy-dependent cellular clearance. Here, we have demonstrated that the two most common autosomal recessive hereditary spastic paraplegia gene products, the SPG15 protein spastizin and the SPG11 protein spatacsin, are pivotal for autophagic lysosome reformation (ALR), a pathway that generates new lysosomes. Lysosomal targeting of spastizin required an intact FYVE domain, which binds phosphatidylinositol 3-phosphate. Loss of spastizin or spatacsin resulted in depletion of free lysosomes, which are competent to fuse with autophagosomes, and an accumulation of autolysosomes, reflecting a failure in ALR. Moreover, spastizin and spatacsin were essential components for the initiation of lysosomal tubulation. Together, these results link dysfunction of the autophagy/lysosomal biogenesis machinery to neurodegeneration.

  18. Poly(amidoamine-Cholesterol Conjugate Nanoparticles Obtained by Electrospraying as Novel Tamoxifen Delivery System

    Directory of Open Access Journals (Sweden)

    R. Cavalli

    2011-01-01

    Full Text Available A new poly(amidoamine-cholesterol (PAA-cholesterol conjugate was synthesized, characterized and used to produce nanoparticles by the electrospraying technique. The electrospraying is a method of liquid atomization that consists in the dispersion of a solution into small charged droplets by an electric field. Tuning the electrospraying process parameters spherical PAA-chol nanoparticles formed. The PAA-cholesterol nanoparticles showed sizes lower than 500 nm and spherical shape. The drug incorporation capacity was investigated using tamoxifen, a lipophilic anticancer drug, as model drug. The incorporation of the tamoxifen did not affect the shape and sizes of nanoparticles showing a drug loading of 40%. Tamoxifen-loaded nanoparticles exhibited a higher dose-dependent cytotoxicity than free tamoxifen, while blank nanoparticles did not show any cytotoxic effect at the same concentrations. The electrospray technique might be proposed to produce tamoxifen-loaded PAA-chol nanoparticle in powder form without any excipient in a single step.

  19. Optical, Electrical and Magnetic Studies of Pi-Conjugated Organic Semiconductor Systems

    Energy Technology Data Exchange (ETDEWEB)

    Vardeny, Zeev Valentine [Univ. of Utah, Salt Lake City, UT (United States)

    2016-09-15

    Over the duration of this grant our group has studied the transient and cw optical response of various π-conjugated polymers, oligomers, single crystals, fullerene molecules and blends of organic donor-acceptor molecules. We have been also involved in complementary experiments such as magneto-optical studies and spin-physics. We have advanced the field of photophysics of these materials by providing information on their excited state energies and primodal and long-lived photoexcitations such as singlet excitons, triplet excitons, polaron-pairs, excimers and exciplexes. We also fabricated various organic optoelectronic devices such as organic light emitting diodes (OLED), electrochemical cells, organic diodes, organic spin-valves (OSV), and organic photovoltaic (OPV) solar cells. These devices benefited the society in terms of cheap and energy saving illumination, as well as harnessing the solar energy.

  20. SN38 conjugated hyaluronic acid gold nanoparticles as a novel system against metastatic colon cancer cells.

    Science.gov (United States)

    Hosseinzadeh, Hosniyeh; Atyabi, Fatemeh; Varnamkhasti, Behrang Shiri; Hosseinzadeh, Reza; Ostad, Seyed Nasser; Ghahremani, Mohammad Hossein; Dinarvand, Rassoul

    2017-06-30

    Combination of chemotherapy and photothermal therapy has been proposed for better treatment of metastatic colon cancer. In this study SN38, a highly potent cytotoxic agent, was conjugated to negatively charged hyaluronic acid (HA), which was deposited on the surface of the positively charged gold nanoparticles via electrostatic interaction. The drug conjugation and its interaction with gold nanoparticles were verified by 1 H NMR and UV-vis spectroscopies, respectively. The prepared SN38-HA gold NPs are negatively charged spherical nanoparticles with an average size of 75±10nm. In vitro release study revealed that drug release in acidic conditions (pH 5.2) was faster than that in physiological pH. Red light emitting diode (LED, 630nm, 30mW) was used as a light source for photothermal experiments. The drug release in acidic conditions was increased up to 30% using red LED illumination (6min) in comparison with experiment carried out indark. The cytotoxicity study on MUC1 positive HT29, SW480 colon cancer cells and MUC1 negative CHO cells, showed higher toxicity of the nanoparticles on HT29 and SW480 cell lines compared to CHO cells. Confocal microscopy images along with flow cytometry analysis confirm the cytotoxicity results. The incubation time for reaching IC50 decreases from 48h to 24h by LED illumination after nanoparticle treatment. Migratory potential of the HT29 and SW480 cell lines was reduced by co-application of SN38-HA gold NPs and LED radiation. Also anti-proliferative study indicates that LED radiation has increased the cytotoxicity of the nanoparticles and this effect is remained up to 8days. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. The preparation and characterization of gold-conjugated polyphenol nanoparticles as a novel delivery system

    Directory of Open Access Journals (Sweden)

    Hsieh DS

    2012-03-01

    Full Text Available Dar-Shih Hsieh1,2, Hsiu-Chin Lu5, Cheng-Cheung Chen1,3, Chang-Jer Wu1,*, Ming-Kung Yeh4,* 1Department of Food Science, National Taiwan Ocean University, Keelung, Taiwan; 2Division of Urology, 3Department of Pathology, Tri-Service General Hospital, 4Institute of Preventive Medicine, National Defence Medical Center, Taipei, Taiwan; 5Department of Laboratory Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan*These authors contributed equally to this workAbstract: Nanogold particles are commonly used in nanomedicine. We generated physical nanogold (pNG conjugated with different ratios of epigallocatechin-3-gallate (EGCG and evaluated its physicochemical properties, antioxidant activity, and cytotoxicity in vitro as well as anticancer activity in vivo. Results showed that the EGCG-pNG conjugates were successfully prepared at ratios between 23:1 and 23:5, with the percentage of EGCG content increasing with the EGCG:pNG ratio from 23:1 (2.0% ± 0.02% to 23:5 (28% ± 0.3%. EGCG-pNG particles at ratios of 23:1 and 23:5 demonstrated significantly decreased size from 500 to 20 nm and decreasing zeta potentials of 21 mV to –22 mV, respectively. At a ratio of 23:2.5, the EGCG-pNG particles (27% EGCG, 50 nm in size, zeta potential of –8 mV showed longer EGCG activity half-life (110 days vs 5 hours, controlled release (2 hours vs 30 minutes, and higher antioxidant activity (four times, as well as inhibition of tumor cell growth, than controls. The present study indicated that EGCG-pNG possesses promising therapeutic potential, based on its strong free-radical scavenging and anticancer activities.Keywords: EGCG, nanoparticles, antioxidant, antitumor activity, nanogold

  2. Bacteriophytochromes control conjugation in Agrobacterium fabrum.

    Science.gov (United States)

    Bai, Yingnan; Rottwinkel, Gregor; Feng, Juan; Liu, Yiyao; Lamparter, Tilman

    2016-08-01

    Bacterial conjugation, the transfer of single stranded plasmid DNA from donor to recipient cell, is mediated through the type IV secretion system. We performed conjugation assays using a transmissible artificial plasmid as reporter. With this assay, conjugation in Agrobacterium fabrum was modulated by the phytochromes Agp1 and Agp2, photoreceptors that are most sensitive in the red region of visible light. In conjugation studies with wild-type donor cells carrying a pBIN-GUSINT plasmid as reporter that lacked the Ti (tumor inducing) plasmid, no conjugation was observed. When either agp1(-) or agp2(-) knockout donor strains were used, plasmid DNA was delivered to the recipient, indicating that both phytochromes suppress conjugation in the wild type donor. In the recipient strains, the loss of Agp1 or Agp2 led to diminished conjugation. When wild type cells with Ti plasmid and pBIN-GUS reporter plasmid were used as donor, a high rate of conjugation was observed. The DNA transfer was down regulated by red or far-red light by a factor of 3.5. With agp1(-) or agp2(-) knockout donor cells, conjugation in the dark was about 10 times lower than with the wild type donor, and with the double knockout donor no conjugation was observed. These results imply that the phytochrome system has evolved to inhibit conjugation in the light. The decrease of conjugation under different temperature correlated with the decrease of phytochrome autophosphorylation. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Identification of potent orally active factor Xa inhibitors based on conjugation strategy and application of predictable fragment recommender system.

    Science.gov (United States)

    Ishihara, Tsukasa; Koga, Yuji; Iwatsuki, Yoshiyuki; Hirayama, Fukushi

    2015-01-15

    Anticoagulant agents have emerged as a promising class of therapeutic drugs for the treatment and prevention of arterial and venous thrombosis. We investigated a series of novel orally active factor Xa inhibitors designed using our previously reported conjugation strategy to boost oral anticoagulant effect. Structural optimization of anthranilamide derivative 3 as a lead compound with installation of phenolic hydroxyl group and extensive exploration of the P1 binding element led to the identification of 5-chloro-N-(5-chloro-2-pyridyl)-3-hydroxy-2-{[4-(4-methyl-1,4-diazepan-1-yl)benzoyl]amino}benzamide (33, AS1468240) as a potent factor Xa inhibitor with significant oral anticoagulant activity. We also reported a newly developed Free-Wilson-like fragment recommender system based on the integration of R-group decomposition with collaborative filtering for the structural optimization process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Detection of bisphenol A in food packaging based on fluorescent conjugated polymer PPESO3 and enzyme system.

    Science.gov (United States)

    Huang, Hui; Li, Yongxin; Liu, Jintong; Tong, Jin; Su, Xingguang

    2015-10-15

    Bisphenol A (BPA) is a kind of carcinogen, which can interfere with the body's endocrine system. In this paper, a new kind of fluorescent sensor for BPA detection was established based on the fluorescent conjugated polymer PPESO3. The oxidative product of BPA is able to quench PPESO3 in the presence of HRP and H2O2, and the quenched PL intensity of PPESO3 was proportionally to the concentration of BPA in the range of 1-100 μmol/L with a detection limit of 4 × 10(-7) mol/L. The proposed method has been applied to detect BPA in eight food packaging samples with satisfactory results. The proposed method has the potential for the assay of BPA in food or food packaging samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Photoluminescence in conjugated polymers

    International Nuclear Information System (INIS)

    Furst, J.E.; Laugesen, R.; Dastoor, P.; McNeill, C.

    2002-01-01

    Full text: Conjugated polymers combine the electronic and optical properties of semiconductors with the processability of polymers. They contain a sequence of alternate single and double carbon bonds so that the overlap of unhybridised p z orbitals creates a delocalised ρ system which gives semiconducting properties with p-bonding (valence) and p* -antibonding (conduction) bands. Photoluminesence (PL) in conjugated polymers results from the radiative decay of singlet excitons confined to a single chain. The present work is the first in a series of studies in our laboratory that will characterize the optical properties of conjugated polymers. The experiment involves the illumination of thin films of conjugated polymer with UV light (I=360 nm) and observing the subsequent fluorescence using a custom-built, fluorescence spectrometer. Photoluminesence spectra provide basic information about the structure of the polymer film. A typical spectrum is shown in the accompanying figure. The position of the first peak is related to the polymer chain length and resolved multiple vibronic peaks are an indication of film structure and morphology. We will also present results related to the optical degradation of these materials when exposed to air and UV light

  6. High-resolution spectroscopy of jet-cooled 1,1 '-diphenylethylene: electronically excited and ionic states of a prototypical cross-conjugated system

    NARCIS (Netherlands)

    Smolarek, S.; Vdovin, A.; Rijs, A.; van Walree, C.A.; Zgierski, M.Z.; Buma, W.J.

    2011-01-01

    The photophysics of a prototypical cross-conjugated π-system, 1,1′-diphenylethylene, have been studied using high-resolution resonance enhanced multiphoton ionization excitation spectroscopy and zero kinetic energy photoelectron spectroscopy, in combination with advanced ab initio calculations. We

  7. A computationally efficient P_1 radiation model for modern combustion systems utilizing pre-conditioned conjugate gradient methods

    International Nuclear Information System (INIS)

    Krishnamoorthy, Gautham

    2017-01-01

    Highlights: • The P_1 radiation model was interfaced with high performance linear solvers. • Pre-conditioned conjugate gradient (PC CG) method improved convergence by 50% • PC CG was more than 30 times faster than classical iterative methods. • The time to solution scaled linearly with increase in problem size employing PC CG. • Employing WSGGM with P_1 model compared reasonably well against benchmark data. - Abstract: The iterative convergence of the P_1 radiation model can be slow in optically thin scenarios when employing classical iterative methods. In order to remedy this shortcoming, an in-house P_1 radiation model was interfaced with high performance, scalable, linear solver libraries. Next, the accuracies of P_1 radiation model calculations was assessed by comparing its predictions against discrete ordinates (DO) model calculations for prototypical problems representative of modern combustion systems. Corresponding benchmark results were also included for comparison. Utilizing Pre-Conditioners (PC) to the Conjugate Gradients (CG) method, the convergence time of the P_1 radiation model reduced by a factor of 30 for modest problem sizes and a factor of 70 for larger sized problems when compared against classical Gauss Seidel sweeps. Further, PC provided 50% computational savings compared to employing CG in a standalone mode. The P_1 model calculation times were about 25–30% of the DO model calculation time. The time to solution also scaled linearly with an increase in problem size. The weighted sum of gray gases model employed in this study in conjunction with the P_1 model provided good agreement against benchmark data with L_2 error norms (defined relative to corresponding DO calculations) improving when isotropic intensities were prevalent.

  8. Systemic co-delivery of doxorubicin and siRNA using nanoparticles conjugated with EGFR-specific targeting peptide to enhance chemotherapy in ovarian tumor bearing mice

    Energy Technology Data Exchange (ETDEWEB)

    Liu, C. W.; Lin, W. J., E-mail: wjlin@ntu.edu.tw [National Taiwan University, Graduate Institute of Pharmaceutical Sciences, School of Pharmacy (China)

    2013-10-15

    This aim of this study was to develop peptide-conjugated nanoparticles (NPs) for systemic co-delivery of siRNA and doxorubicin to enhance chemotherapy in epidermal growth factor receptor (EGFR) high-expressed ovarian tumor bearing mice. The active targeting NPs were prepared using heptapeptide-conjugated poly(d,l-lactic-co-glycolic acid)-poly(ethylene glycol). The particle sizes of peptide-free and peptide-conjugated NPs were 159.3 {+-} 32.5 and 184.0 {+-} 52.9 nm, respectively, with zeta potential -21.3 {+-} 3.8 and -15.3 {+-} 2.8 mV. The peptide-conjugated NPs uptake were more efficient in EGFR high-expressed SKOV3 cells than in EGFR low-expressed HepG2 cells due to heptapeptide specificity. The NPs were used to deliver small molecule anticancer drug (e.g., doxorubicin) and large molecule genetic agent (e.g., siRNA). The IC{sub 50} of doxorubicin-loaded peptide-conjugated NPs (0.09 {+-} 0.06 {mu}M) was significantly lower than peptide-free NPs (5.72 {+-} 2.64 {mu}M). The similar result was observed in siRNA-loaded NPs. The peptide-conjugated NPs not only served as a nanocarrier to efficiently deliver doxorubicin and siRNA to EGFR high-expressed ovarian cancer cells but also increased the intracellular accumulation of the therapeutic agents to induce assured anti-tumor growth effect in vivo.

  9. Optically Detected Magnetic Resonance Studies on π-conjugated semiconductor systems

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying [Iowa State Univ., Ames, IA (United States)

    2011-01-01

    Optically Detected Magnetic Resonance (ODMR) techniques were used to investigate the dynamics of excitons and charge carriers in π-conjugated organic semiconductors. Degradation behavior of the negative spin-1/2 electroluminescence-detected magnetic resonance (ELDMR) was observed in Alq3 devices. The increase in the resonance amplitude implies an increasing bipolaron formation during degradation, which might be the result of growth of charge traps in the device. The same behavior of the negative spin-1/2 ELDMR was observed in 2wt% Rubrene doped Tris(8-hydroxyquinolinato)aluminium (Alq3) devices. However, with increasing injection current, a positive spin-1/2 ELDMR, together with positive spin 1 triplet powder patterns at ΔmS=±1 and ΔmS=±2, emerges. Due to the similarities in the frequency dependences of single and double modulated ELDMR and the photoluminescence-detected magnetic resonance (PLDMR) results in poly[2-methoxy-5-(2 -ethyl-hexyloxy)-1,4-phenyl ene vinylene] (MEH-PPV) films, the mechanism for this positive spin-1/2 ELDMR was assigned to enhanced triplet-polaron quenching under resonance conditions. The ELDMR in rubrene doped Alq3 devices provides a path to investigate charge distribution in the device under operational conditions. Combining the results of several devices with different carrier blocking properties and the results from transient EL, it was concluded trions not only exist near buffer layer but also exist in the electron transport layer. This TPQ model can also be used to explain the positive spin-1/2 PLDMR in poly(3-hexylthiophene) (P3HT) films at low temperature and in MEH-PPV films at various temperatures up to room temperature. Through quantitative analysis, TE-polaron quenching (TPQ) model is shown having the ability to explain most behaviors of the positive spin-1/2 resonance. Photocurrent detected magnetic resonance (PCDMR) studies on MEH-PPV devices revealed a novel transient resonance signal. The signal

  10. Fetoscopic laser coagulation of intertwin anastomoses reduces discordant placental autophagic activities in discordant twin growth

    Directory of Open Access Journals (Sweden)

    Yao-Lung Chang

    2015-10-01

    Conclusion: The discordance of placenta autophagic activity in the monochorionic twin with sIUGR was reduced after laser coagulation of the intertwin anastomoses, which may result from the effect of correction of the discordant intertwin placenta perfusion.

  11. Testosterone regulates the autophagic clearance of androgen binding protein in rat Sertoli cells

    Science.gov (United States)

    Ma, Yi; Yang, Hao-Zheng; Xu, Long-Mei; Huang, Yi-Ran; Dai, Hui-Li; Kang, Xiao-Nan

    2015-01-01

    Dysregulation of androgen-binding protein (ABP) is associated with a number of endocrine and andrology diseases. However, the ABP metabolism in Sertoli cells is largely unknown. We report that autophagy degrades ABP in rat Sertoli cells, and the autophagic clearance of ABP is regulated by testosterone, which prolongs the ABP biological half-life by inhibiting autophagy. Further studies identified that the autophagic clearance of ABP might be selectively regulated by testosterone, independent of stress (hypoxia)-induced autophagic degradation. These data demonstrate that testosterone up-regulates ABP expression at least partially by suppressing the autophagic degradation. We report a novel finding with respect to the mechanisms by which ABP is cleared, and by which the process is regulated in Sertoli cells. PMID:25745956

  12. Fiber Nonlinearity Post-Compensation by Optical Phase Conjugation for 40Gb/s CO-OFDM Systems

    International Nuclear Information System (INIS)

    Qiao Yao-Jun; Liu Xue-Jun; Ji Yue-Feng

    2011-01-01

    Fiber nonlinearity impairments in a 40-Gb/s coherent optical orthogonal frequency division multiplexing (COOFDM) system are post-compensated for by a new method of fiber nonlinearity post-compensation (FNPC). The FNPC located before the CO-OFDM receiver includes an optical phase conjugation (OPC) unit and a subsequent 80-km-high nonlinear fiber (HNLF) as a fiber nonlinearity compensator. The OPC unit is based on a four wave mixing effect in a semiconductor optical amplifier. The fiber nonlinearity impairments in the transmission link are post-compensated for after OPC by transmission through the HNLF with a large nonlinearity coefficient. Simulation results show that the nonlinear threshold (NLT) (for Q > 10 dB) can be increased by about 2.5 dB and the maximum Q factor is increased by about 1.2 dB for the single-channel 40-Gb/s CO-OFDM system with periodic dispersion maps. In the 50-GHz channel spacing wavelength-division-multiplexing system, the NLT increases by 1.1 dB, equating to a 0.7 dB improvement for the maximum Q factor. (fundamental areas of phenomenology(including applications))

  13. Absolute continuity of autophage measures on finite-dimensional vector spaces

    Energy Technology Data Exchange (ETDEWEB)

    Raja, C R.E. [Stat-Math Unit, Indian Statistical Institute, Bangalore (India); [Abdus Salam International Centre for Theoretical Physics, Trieste (Italy)]. E-mail: creraja@isibang.ac.in

    2002-06-01

    We consider a class of measures called autophage which was introduced and studied by Szekely for measures on the real line. We show that the autophage measures on finite-dimensional vector spaces over real or Q{sub p} are infinitely divisible without idempotent factors and are absolutely continuous with bounded continuous density. We also show that certain semistable measures on such vector spaces are absolutely continuous. (author)

  14. SEARCHING FOR BINARY Y DWARFS WITH THE GEMINI MULTI-CONJUGATE ADAPTIVE OPTICS SYSTEM (GeMS)

    International Nuclear Information System (INIS)

    Opitz, Daniela; Tinney, C. G.; Faherty, Jacqueline K.; Sweet, Sarah; Gelino, Christopher R.; Kirkpatrick, J. Davy

    2016-01-01

    The NASA Wide-field Infrared Survey Explorer (WISE) has discovered almost all the known members of the new class of Y-type brown dwarfs. Most of these Y dwarfs have been identified as isolated objects in the field. It is known that binaries with L- and T-type brown dwarf primaries are less prevalent than either M-dwarf or solar-type primaries, they tend to have smaller separations and are more frequently detected in near-equal mass configurations. The binary statistics for Y-type brown dwarfs, however, are sparse, and so it is unclear if the same trends that hold for L- and T-type brown dwarfs also hold for Y-type ones. In addition, the detection of binary companions to very cool Y dwarfs may well be the best means available for discovering even colder objects. We present results for binary properties of a sample of five WISE Y dwarfs with the Gemini Multi-Conjugate Adaptive Optics System. We find no evidence for binary companions in these data, which suggests these systems are not equal-luminosity (or equal-mass) binaries with separations larger than ∼0.5–1.9 AU. For equal-mass binaries at an age of 5 Gyr, we find that the binary binding energies ruled out by our observations (i.e., 10 42 erg) are consistent with those observed in previous studies of hotter ultra-cool dwarfs

  15. Protein carriers of conjugate vaccines

    Science.gov (United States)

    Pichichero, Michael E

    2013-01-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products. PMID:23955057

  16. Design and Synthesis of New Cholesterol-Conjugated 5-Fluorouracil: A Novel Potential Delivery System for Cancer Treatment

    Directory of Open Access Journals (Sweden)

    Awwad A. Radwan

    2014-08-01

    Full Text Available Cholesterol-conjugated 5-fluorouracil prodrugs were designed to be carried in vivo via low density lipoproteins (LDL and subsequently undergo LDL-receptor-mediated internalisation into cancer cells. In vivo anti-cancer evaluation was performed using 5-fluorouracil-cholesterol conjugate in a mouse model. The obtained prodrugs were more potent than 5-fluorouracil control drug at the same 5-fluorouracil content (3 mg·kg−1.

  17. Graphene oxide quantum dots disrupt autophagic flux by inhibiting lysosome activity in GC-2 and TM4 cell lines

    International Nuclear Information System (INIS)

    Ji, Xiaoli; Xu, Bo; Yao, Mengmeng; Mao, Zhilei; Zhang, Yuqing; Xu, Guofeng; Tang, Qiusha; Wang, Xinru; Xia, Yankai

    2016-01-01

    Graphene oxide quantum dots (GOQDs) have broad application prospects in many areas including bioimaging, drug delivery, DNA cleavage system, sensors and photocatalyst. Recently, increasing concerns have been raised about their biocompatibility, but studies about the effects of GOQDs on male reproductive system are still lacking. In this work, we explored the effects and molecular mechanisms of GOQDs on GC-2 and TM4 cells. We found autophagosome accumulation in GC-2 and TM4 cells after GOQDs treatment. Both LC3-II/LC3-I ratio and p62 levels increased, and the chloroquine-induced accumulation of LC3-II didn’t enhance in the presence of GOQDs, which indicated that GOQDs blocked autophagic flux. Further studies found that the fusion between autophagosome and lysosome was not inhibited by GOQDs, but the proteolytic capacity of lysosome was weakened and both the expression and activity of cathepsin B reduced. Taken together, these results suggested that GOQDs blocked autophagic flux by decreasing the amount and enzymatic activity of cathepsin B and inhibiting lysosome proteolytic capacity in GC-2 and TM4 cells, which might have a potential hazard to male reproduction.

  18. Phospholipase C-related catalytically inactive protein participates in the autophagic elimination of Staphylococcus aureus infecting mouse embryonic fibroblasts.

    Directory of Open Access Journals (Sweden)

    Kae Harada-Hada

    Full Text Available Autophagy is an intrinsic host defense system that recognizes and eliminates invading bacterial pathogens. We have identified microtubule-associated protein 1 light chain 3 (LC3, a hallmark of autophagy, as a binding partner of phospholipase C-related catalytically inactive protein (PRIP that was originally identified as an inositol trisphosphate-binding protein. Here, we investigated the involvement of PRIP in the autophagic elimination of Staphylococcus aureus in infected mouse embryonic fibroblasts (MEFs. We observed significantly more LC3-positive autophagosome-like vacuoles enclosing an increased number of S. aureus cells in PRIP-deficient MEFs than control MEFs, 3 h and 4.5 h post infection, suggesting that S. aureus proliferates in LC3-positive autophagosome-like vacuoles in PRIP-deficient MEFs. We performed autophagic flux analysis using an mRFP-GFP-tagged LC3 plasmid and found that autophagosome maturation is significantly inhibited in PRIP-deficient MEFs. Furthermore, acidification of autophagosomes was significantly inhibited in PRIP-deficient MEFs compared to the wild-type MEFs, as determined by LysoTracker staining and time-lapse image analysis performed using mRFP-GFP-tagged LC3. Taken together, our data show that PRIP is required for the fusion of S. aureus-containing autophagosome-like vacuoles with lysosomes, indicating that PRIP is a novel modulator in the regulation of the innate immune system in non-professional phagocytic host cells.

  19. Development of methods for the decrease in instability of recycling water of conjugated closed-circuit cooling system of HPP

    Science.gov (United States)

    Chichirov, A. A.; Chichirova, N. D.; Vlasov, S. M.; Lyapin, A. I.; Misbakhov, R. Sh.; Silov, I. Yu.; Murtazin, A. I.

    2016-10-01

    On Russian HPPs, conjugated closed-circuit cooling systems, where purge water is used as initial for water-treatment facilities, are widespread. For this reason, it is impossible to use general methods for the stabilization treatment of recycling water in order to prevent scale formation in the units of a system, namely, turbine condensers and cooling towers. In this paper, the methods for the decrease in the instability of recycling water using the methods of chemical engineering, such as stabilization and synchronization of flows and organization of recycles, are suggested. The results of an industrial experiment on the implementation of stabilization treatment of recycling water by the organization of recycle are given. The experiment was carried out on Kazan CHPP-3. The flow scheme involved the recycle of chemically purified water (CPW) for the heat network make-up to the closed-circuit cooling system. The experiment was carried out at three stages with the gradual change of the consumption of the recycle, namely, 0, 50, and 100 t/h. According to the results of experiments, the reliable decrease in the rate of the sedimentation was recorded on the units of the system, namely, turbine condenser and chimney-type cooling tower. This is caused by two reasons. Firstly, this is periodic excessive concentration of recycling water due to the nonstationary character of inlet and outlet flows. Secondly, this is seasonal (particularly, in the summer period) exceeding of the evaporation coefficient. As a result of stabilization and synchronization of flows and organization of recycles, the quality of clarified and chemically purified water for the heat network make-up increases and the corrosion of iron- and copper-containing structural materials decreases. A natural decrease in temperature drop on the operating turbine condensers is mentioned.

  20. Effects of Epigallocatechin-3-Gallate on Autophagic Lipolysis in Adipocytes

    Directory of Open Access Journals (Sweden)

    Sang-Nam Kim

    2017-06-01

    Full Text Available Previous studies demonstrated effects of green tea on weight loss; however, green tea-induced modulation of adipocyte function is not fully understood. Here, we investigated effects of the major green tea phytochemical, epigallocatechin-3-gallate (EGCG on triglyceride contents, lipolysis, mitochondrial function, and autophagy, in adipocytes differentiated from C3H10T1/2 cells and immortalized pre-adipocytes in vitro. EGCG reduced the triglycerol content significantly in adipocytes by 25%, comparable to the nutrient starvation state. EGCG did not affect protein kinase A signaling or brown adipocyte marker expression in adipocytes; however, EGCG increased autophagy, as measured by autophagy flux analysis and immunoblot analysis of LC3B, ATG7, and Beclin1. EGCG treatment reduced mitochondrial membrane potential by 56.8% and intracellular ATP levels by 49.1% compared to controls. Although mammalian target of rapamycin signaling was not upregulated by EGCG treatment, EGCG treatment induced AMP-activated protein kinase phosphorylation, indicating an energy-depleted state. In addition, EGCG increased the association between RAB7 and lipid droplets, suggesting that lipophagy was activated. Finally, knockdown of Rab7 attenuated the EGCG-dependent reduction in lipid contents. Collectively, these results indicated that EGCG upregulated autophagic lipolysis in adipocytes, supporting the therapeutic potential of EGCG as a caloric restriction mimetic to prevent obesity and obesity-related metabolic diseases.

  1. Labile conjugation of a hydrophilic drug to PLA oligomers to modify a drug delivery system: cephradin in a PLAGA matrix.

    Science.gov (United States)

    Ustariz-Peyret, C; Coudane, J; Vert, M; Kaltsatos, V; Boisramené, B

    2000-01-01

    The physical entrapment of a hydrophilic drug within degradable microspheres is generally difficult because of poor entrapment yield and/or fast release, depending on the microsphere fabrication method. In order to counter the effects of drug hydrophilicity, it is proposed to covalently attach the drug to lactic acid oligomers, with the aim of achieving temporary hydrophobization and slower release controlled by the separation of the drug from the degradable link within the polymer matrix. This strategy was tested on microspheres of the antibiotic cephradin. As the prodrug form, the entrapment of the drug was almost quantitative. The prodrug did degrade in an aqueous medium, modelling body fluids, but cleavage did not occur at the drug-oligomer junction and drug molecules bearing two lactyl residual units were released. When the prodrug is entrapped within a PLAGA matrix, no release was observed within the experimental time period. However, data suggest that conjugation via a bond more sensitive to hydrolysis than the main chain PLA ester bonds should make the system work as desired.

  2. Optimal Allocation of Thermal-Electric Decoupling Systems Based on the National Economy by an Improved Conjugate Gradient Method

    Directory of Open Access Journals (Sweden)

    Shuang Rong

    2015-12-01

    Full Text Available Aiming to relieve the large amount of wind power curtailment during the heating period in the North China region, a thermal-electric decoupling (TED approach is proposed to both bring down the constraint of forced power output of combined heat and power plants and increase the electric load level during valley load times that assist the power grid in consuming more wind power. The operating principles of the thermal-electric decoupling approach is described, the mathematical model of its profits is developed, the constraint conditions of its operation are listed, also, an improved parallel conjugate gradient is utilized to bypass the saddle problem and accelerate the optimal speed. Numerical simulations are implemented and reveal an optimal allocation of TED which with a rated power of 280 MW and 185 MWh heat storage capacity are possible. This allocation of TED could bring approximately 16.9 billion Yuan of economic profit and consume more than 80% of the surplus wind energy which would be curtailed without the participation of TED. The results in this article verify the effectiveness of this method that could provide a referential guidance for thermal-electric decoupling system allocation in practice.

  3. Ligand-conjugated mesoporous silica nanorattles based on enzyme targeted prodrug delivery system for effective lung cancer therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sundarraj, Shenbagamoorthy, E-mail: sundarrajbu09@gmail.com [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Thangam, Ramar [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Department of Virology, King Institute of Preventive Medicine and Research, Guindy, Chennai 600 032, TN (India); Sujitha, Mohanan V.; Vimala, Karuppaiya [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Kannan, Soundarapandian, E-mail: skperiyaruniv@gmail.com [Proteomics and Molecular Cell Physiology Laboratory, Department of Zoology, Bharathiar University, Coimbatore 641 046, TN (India); Department of Zoology, Periyar University, Salem 636 011, TN (India)

    2014-03-15

    Epidermal growth factor receptor antibody (EGFRAb) conjugated silica nanorattles (SNs) were synthesized and used to develop receptor mediated endocytosis for targeted drug delivery strategies for cancer therapy. The present study determined that the rate of internalization of silica nanorattles was found to be high in lung cancer cells when compared with the normal lung cells. EGFRAb can specifically bind to EGFR, a receptor that is highly expressed in lung cancer cells, but is expressed at low levels in other normal cells. Furthermore, in vitro studies clearly substantiated that the cPLA{sub 2}α activity, arachidonic acid release and cell proliferation were considerably reduced by pyrrolidine-2 loaded EGFRAb-SN in H460 cells. The cytotoxicity, cell cycle arrest and apoptosis were significantly induced by the treatment of pyrrolidine-2 loaded EGFRAb-SN when compared with free pyrrolidine-2 and pyrrolidine-2 loaded SNs in human non-small cell lung cancer cells. An in vivo toxicity assessment showed that silica nanorattles and EGFRAb-SN-pyrrolidine-2 exhibited low systemic toxicity in healthy Balb/c mice. The EGFRAb-SN-pyrrolidine-2 showed a much better antitumor activity (38%) with enhanced tumor inhibition rate than the pyrrolidine-2 on the non-small cell lung carcinoma subcutaneous model. Thus, the present findings validated the low toxicity and high therapeutic potentials of EGFRAb-SN-pyrrolidine-2, which may provide a convincing evidence of the silica nanorattles as new potential carriers for targeted drug delivery systems. - Highlights: • EGFRAb-SN developed for receptor-mediated Drug delivery system (DDS). • EGFRAb-SN-pyrrolidine-2 targeted DDS for cPLA2α inhibition in NSLC. • Study indicates EGFRAb-SN-pyrrolidine-2 as an efficient in target dug delivery carrier. • Study explains entire efficiency of EGFRAb-SN-pyrrolidine-2 in vitro and in vivo models.

  4. Ligand-conjugated mesoporous silica nanorattles based on enzyme targeted prodrug delivery system for effective lung cancer therapy

    International Nuclear Information System (INIS)

    Sundarraj, Shenbagamoorthy; Thangam, Ramar; Sujitha, Mohanan V.; Vimala, Karuppaiya; Kannan, Soundarapandian

    2014-01-01

    Epidermal growth factor receptor antibody (EGFRAb) conjugated silica nanorattles (SNs) were synthesized and used to develop receptor mediated endocytosis for targeted drug delivery strategies for cancer therapy. The present study determined that the rate of internalization of silica nanorattles was found to be high in lung cancer cells when compared with the normal lung cells. EGFRAb can specifically bind to EGFR, a receptor that is highly expressed in lung cancer cells, but is expressed at low levels in other normal cells. Furthermore, in vitro studies clearly substantiated that the cPLA 2 α activity, arachidonic acid release and cell proliferation were considerably reduced by pyrrolidine-2 loaded EGFRAb-SN in H460 cells. The cytotoxicity, cell cycle arrest and apoptosis were significantly induced by the treatment of pyrrolidine-2 loaded EGFRAb-SN when compared with free pyrrolidine-2 and pyrrolidine-2 loaded SNs in human non-small cell lung cancer cells. An in vivo toxicity assessment showed that silica nanorattles and EGFRAb-SN-pyrrolidine-2 exhibited low systemic toxicity in healthy Balb/c mice. The EGFRAb-SN-pyrrolidine-2 showed a much better antitumor activity (38%) with enhanced tumor inhibition rate than the pyrrolidine-2 on the non-small cell lung carcinoma subcutaneous model. Thus, the present findings validated the low toxicity and high therapeutic potentials of EGFRAb-SN-pyrrolidine-2, which may provide a convincing evidence of the silica nanorattles as new potential carriers for targeted drug delivery systems. - Highlights: • EGFRAb-SN developed for receptor-mediated Drug delivery system (DDS). • EGFRAb-SN-pyrrolidine-2 targeted DDS for cPLA2α inhibition in NSLC. • Study indicates EGFRAb-SN-pyrrolidine-2 as an efficient in target dug delivery carrier. • Study explains entire efficiency of EGFRAb-SN-pyrrolidine-2 in vitro and in vivo models

  5. Charge Transport in Conjugated Materials: From Theoretical Models to Experimental Systems

    International Nuclear Information System (INIS)

    Olivier, Yoann; Cornil, Jerome; Muccioli, Luca; Zannoni, Claudio

    2008-01-01

    Charge carrier mobility is the key quantity to characterize the charge transport properties in devices. Based on earlier work of Baessler and co-workers, we set up a Monte-Carlo approach that allows us to calculate mobility using transfer rates derived from Marcus theory. The parameters entering into the rate expression are evaluated by means of different quantum-chemical techniques. Our approach is applied here to a model one-dimensional system made of pentacene molecules as well as to real systems such as crystalline structures and columnar liquid crystal phases.

  6. Gauge systems and functions, hermitian operators and clocks as conjugate functions for the constraints

    International Nuclear Information System (INIS)

    Cuesta, Vladimir; Vergara, Jose David; Montesinos, Merced

    2011-01-01

    We work with gauge systems and using gauge invariant functions we study its quantum counterpart and we find if all these operators are self adjoint or not. Our study is divided in two cases, when we choose clock or clocks that its Poisson brackets with the set of constraints is one or it is different to one. We show some transition amplitudes.

  7. Evaluation of antitumor effects of folate-conjugated methyl-β-cyclodextrin in melanoma.

    Science.gov (United States)

    Motoyama, Keiichi; Onodera, Risako; Tanaka, Nao; Kameyama, Kazuhisa; Higashi, Taishi; Kariya, Ryusho; Okada, Seiji; Arima, Hidetoshi

    2015-01-01

    Melanoma is a life-threatening disorder and its incidence is increasing gradually. Despite the numerous treatment approaches, conventional systemic chemotherapy has not reduced the mortality rate among melanoma patients, probably due to the induction of toxicity to normal tissues. Recently, we have developed folate-conjugated methyl-β-cyclodextrin (FA-M-β-CyD) and clarified its potential as a new antitumor agent involved in autophagic cell death. However, it remains uncertain whether FA-M-β-CyD exerts anticancer effects against melanomas. Therefore, in this study, we investigated the effects of FA-M-β-CyD on the folate receptor-α (FR-α)-expressing melanoma cell-selective cytotoxic effect. FA-M-β-CyD showed cytotoxic effects in Ihara cells, a human melanoma cell line expressing FR-α. In sharp contrast to methyl-β-cyclodextrin, FA-M-β-CyD entered Ihara cells [FR-α(+)] through FR-α-mediated endocytosis. Additionally, FA-M-β-CyD elicited the formation of autophagosomes in Ihara cells. Notably, FA-M-β-CyD suppressed melanoma growth in BALB/c nude recombinase-activating gene-2 (Rag-2)/Janus kinase 3 (Jak3) double deficient mice bearing Ihara cells. Therefore, these results suggest that FA-M-β-CyD could be utilized as a potent anticancer agent for melanoma chemotherapy by regulating autophagy.

  8. A composite step conjugate gradients squared algorithm for solving nonsymmetric linear systems

    Science.gov (United States)

    Chan, Tony; Szeto, Tedd

    1994-03-01

    We propose a new and more stable variant of the CGS method [27] for solving nonsymmetric linear systems. The method is based on squaring the Composite Step BCG method, introduced recently by Bank and Chan [1,2], which itself is a stabilized variant of BCG in that it skips over steps for which the BCG iterate is not defined and causes one kind of breakdown in BCG. By doing this, we obtain a method (Composite Step CGS or CSCGS) which not only handles the breakdowns described above, but does so with the advantages of CGS, namely, no multiplications by the transpose matrix and a faster convergence rate than BCG. Our strategy for deciding whether to skip a step does not involve any machine dependent parameters and is designed to skip near breakdowns as well as produce smoother iterates. Numerical experiments show that the new method does produce improved performance over CGS on practical problems.

  9. Autophagic flux is highly active in early mitosis and differentially regulated throughout the cell cycle.

    Science.gov (United States)

    Li, Zhiyuan; Ji, Xinmiao; Wang, Dongmei; Liu, Juanjuan; Zhang, Xin

    2016-06-28

    Mitosis is a fast process that involves dramatic cellular remodeling and has a high energy demand. Whether autophagy is active or inactive during the early stages of mitosis in a naturally dividing cell is still debated. Here we aimed to use multiple assays to resolve this apparent discrepancy. Although the LC3 puncta number was reduced in mitosis, the four different cell lines we tested all have active autophagic flux in both interphase and mitosis. In addition, the autophagic flux was highly active in nocodazole-induced, double-thymidine synchronization released as well as naturally occurring mitosis in HeLa cells. Multiple autophagy proteins are upregulated in mitosis and the increased Beclin-1 level likely contributes to the active autophagic flux in early mitosis. It is interesting that although the autophagic flux is active throughout the cell cycle, early mitosis and S phase have relatively higher autophagic flux than G1 and late G2 phases, which might be helpful to degrade the damaged organelles and provide energy during S phase and mitosis.

  10. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    International Nuclear Information System (INIS)

    Lyu, Qing; Tou, Fangfang; Su, Hong; Wu, Xiaoyong; Chen, Xinyi; Zheng, Zhi

    2015-01-01

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway

  11. The natural product peiminine represses colorectal carcinoma tumor growth by inducing autophagic cell death

    Energy Technology Data Exchange (ETDEWEB)

    Lyu, Qing [School of Life Sciences, Tsinghua University, Beijing, 100084 (China); Key Lab in Healthy Science and Technology, Division of Life Science, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055 (China); Tou, Fangfang [Jiangxi Provincial Key Lab of Oncology Translation Medicine, Jiangxi Cancer Hospital, Nanchang, 330029 (China); Su, Hong; Wu, Xiaoyong [First Affiliated Hospital, Guiyang College of Traditional Chinese Medicine, Guiyang, 550002 (China); Chen, Xinyi [Department of Hematology and Oncology, Beijing University of Chinese Medicine, Beijing, 100029 (China); Zheng, Zhi, E-mail: zheng_sheva@hotmail.com [Jiangxi Provincial Key Lab of Oncology Translation Medicine, Jiangxi Cancer Hospital, Nanchang, 330029 (China)

    2015-06-19

    Autophagy is evolutionarily conservative in eukaryotic cells that engulf cellular long-lived proteins and organelles, and it degrades the contents through fusion with lysosomes, via which the cell acquires recycled building blocks for the synthesis of new molecules. In this study, we revealed that peiminine induces cell death and enhances autophagic flux in colorectal carcinoma HCT-116 cells. We determined that peiminine enhances the autophagic flux by repressing the phosphorylation of mTOR through inhibiting upstream signals. Knocking down ATG5 greatly reduced the peiminine-induced cell death in wild-type HCT-116 cells, while treating Bax/Bak-deficient cells with peiminine resulted in significant cell death. In summary, our discoveries demonstrated that peiminine represses colorectal carcinoma cell proliferation and cell growth by inducing autophagic cell death. - Highlights: • Peiminine induces autophagy and upregulates autophagic flux. • Peiminine represses colorectal carcinoma tumor growth. • Peiminine induces autophagic cell death. • Peiminine represses mTOR phosphorylation by influencing PI3K/Akt and AMPK pathway.

  12. Constructing a mixed π-conjugated bridge to effectively enhance the nonlinear optical response in the Möbius cyclacene-based systems.

    Science.gov (United States)

    Chen, Liwei; Yu, Guangtao; Chen, Wei; Tu, Chunyun; Zhao, Xingang; Huang, Xuri

    2014-06-14

    Using density functional theory computations, employing the concept of a mixed π-conjugated bridge can effectively improve the first hyperpolarizability (β0) of Möbius cyclacene (MC)-based systems with a D-π-A framework. This mixed π-conjugated bridge is constructed by applying a -(CH=CH)x-NH2 or -(CH=CH)x-NO2 chain to modify [8]MC, which can lead to a considerable β0 value (e.g. [8]MC-(CH=CH)12-NO2 (9.87 × 10(5) au) with only a certain chain length), much larger than the sole [8]MC (261 au) and the corresponding NH2/NO2-modified polyethylene chain with the same π-conjugated length. It is revealed that the substituent sites and the chain length can play a crucial role in improving β0 values of these MC-chain systems, where the β0 value can monotonically increase with increasing -(CH=CH)x- length, and the substituent electron-withdrawing -(CH=CH)x-NO2 chain is superior to the parallel electron-donating -(CH=CH)x-NH2. These appealing findings can provide valuable insights into the design of novel NLO materials based on MC.

  13. Biosynthesis of insulin-silk fibroin nanoparticles conjugates and in vitro evaluation of a drug delivery system

    Science.gov (United States)

    Yan, Hai-Bo; Zhang, Yu-Qing; Ma, Yong-Lei; Zhou, Li-Xia

    2009-11-01

    Silk fibroin derived from Bombyx mori is a biomacromolecular protein with outstanding biocompatibility. When it was dissolved in highly concentrated CaCl2 solution and then the mixture of the protein and salt was subjected to desalting treatments for long time in flowing water, the resulting liquid silk was water-soluble polypeptides with different molecular masses, ranging from 8 to 70 kDa. When the liquid silk was introduced rapidly into acetone, silk protein nanoparticles with a range of 40-120 nm in diameter could be obtained. The crystalline silk nanoparticles could be conjugated covalently with insulin alone with cross-linking reagent glutaraldehyde. In vitro properties of the insulin-silk fibroin nanoparticles (Ins-SFN) bioconjugates were determined by Enzyme-Linked Immunosorbent Assay (ELISA). The optimal conditions for the biosynthesis of Ins-SFN bioconjugates were investigated. The Ins-SFN constructs obtained by 8 h of covalent cross-linking with 0.7% cross-linking reagent and the proportion of insulin and SFN being 30 IU: 15 mg showed much higher recoveries (90-115%). When insulin was coupled covalently with silk nanoparticles, the resistance of the modified insulin to trypsin digestion and in vitro stability in human serum were greatly enhanced as compared with insulin alone. The results in human serum indicated that the half-life in vitro of the biosynthesized Ins-SFN derivatives was about 2.5 times more than that of native insulin. Therefore, the silk protein nanoparticles have the potential values for being studied and developed as a new bioconjugate for enzyme/polypeptide drug delivery system.

  14. Magnetic and transport properties of conjugated and cumulated molecules: the π-system enlightens part of the story

    DEFF Research Database (Denmark)

    Sarbadhikary, Prodipta; Shil, Suranjan; Misra, Anirban

    2018-01-01

    We have investigated the intramolecular magnetic exchange coupling constants (J) for a series of nitronyl nitroxide diradicals connected by a range of linear conjugated and cumulene couplers focusing on the unusual π-interaction properties within the couplers. Distance between radical centers, sp...

  15. Rapid and sustained systemic circulation of conjugated gut microbiol catabolites after single-dose black tea extract consumption

    NARCIS (Netherlands)

    Duynhoven, van J.P.M.; Hooft, van der J.J.J.; Dorsten, van F.A.; Peters, S.; Foltz, M.; Gomez-Roldan, V.; Vervoort, J.J.M.; Vos, de R.C.H.

    2014-01-01

    Gut microbial catabolites of black tea polyphenols (BTPs) have been proposed to exert beneficial cardiovascular bioactivity. This hypothesis is difficult to verify because the conjugation patterns and pharmacokinetics of these catabolites are largely unknown. The objective of our study was to

  16. The Protective Effect of Gangliosides on Lead (Pb)-Induced Neurotoxicity Is Mediated by Autophagic Pathways.

    Science.gov (United States)

    Meng, Hongtao; Wang, Lan; He, Junhong; Wang, Zhufeng

    2016-03-25

    Lead (Pb) is a ubiquitous environmental and industrial pollutant and can affect intelligence development and the learning ability and memory of children. Therefore, necessary measures should be taken to protect the central nervous system (CNS) from Pb toxicity. Gangliosides are sialic acid-containing glycosphingolipids that are constituents of mammalian cell membranes and are more abundantly expressed in the CNS. Studies have shown that gangliosides constitute a useful tool in the attempt to promote functional recovery of CNS and can reverse Pb-induced impairments of synaptic plasticity in rats. However, the detailed mechanisms have yet to be fully understood. In our present study, we tried to investigate the role of gangliosides in Pb-induced injury in hippocampus neurons and to further confirm the detailed mechanism. Our results show that Pb-induced injuries in the spatial reference memory were associated with a reduction of cell viability and cell apoptosis, and treatment with gangliosides markedly ameliorated the Pb-induced injury by inhibition of apoptosis action. Gangliosides further attenuated Pb-induced the abnormal autophagic process by regulation of mTOR pathways. In summary, our study establishes the efficacy of gangliosides as neuroprotective agents and provides a strong rationale for further studies on the underlying mechanisms of their neuroprotective functions.

  17. The Protective Effect of Gangliosides on Lead (Pb-Induced Neurotoxicity Is Mediated by Autophagic Pathways

    Directory of Open Access Journals (Sweden)

    Hongtao Meng

    2016-03-01

    Full Text Available Lead (Pb is a ubiquitous environmental and industrial pollutant and can affect intelligence development and the learning ability and memory of children. Therefore, necessary measures should be taken to protect the central nervous system (CNS from Pb toxicity. Gangliosides are sialic acid-containing glycosphingolipids that are constituents of mammalian cell membranes and are more abundantly expressed in the CNS. Studies have shown that gangliosides constitute a useful tool in the attempt to promote functional recovery of CNS and can reverse Pb-induced impairments of synaptic plasticity in rats. However, the detailed mechanisms have yet to be fully understood. In our present study, we tried to investigate the role of gangliosides in Pb-induced injury in hippocampus neurons and to further confirm the detailed mechanism. Our results show that Pb-induced injuries in the spatial reference memory were associated with a reduction of cell viability and cell apoptosis, and treatment with gangliosides markedly ameliorated the Pb-induced injury by inhibition of apoptosis action. Gangliosides further attenuated Pb-induced the abnormal autophagic process by regulation of mTOR pathways. In summary, our study establishes the efficacy of gangliosides as neuroprotective agents and provides a strong rationale for further studies on the underlying mechanisms of their neuroprotective functions.

  18. 17-AAG increases autophagic removal of mutant androgen receptor in spinal and bulbar muscular atrophy.

    Science.gov (United States)

    Rusmini, Paola; Simonini, Francesca; Crippa, Valeria; Bolzoni, Elena; Onesto, Elisa; Cagnin, Monica; Sau, Daniela; Ferri, Nicola; Poletti, Angelo

    2011-01-01

    Several types of motorneuron diseases are linked to neurotoxic mutant proteins. These acquire aberrant conformations (misfolding) that trigger deleterious downstream events responsible for neuronal dysfunction and degeneration. The pharmacological removal of misfolded proteins might thus be useful in these diseases. We utilized a peculiar motorneuronal disease model, spinobulbar muscular atrophy (SBMA), in which the neurotoxicity of the protein involved, the mutant androgen receptor (ARpolyQ), can be modulated by its ligand testosterone (T). 17-(allylamino)-17-demethoxygeldanamycin (17-AAG) has already been proven to exert beneficial action in SBMA. Here we demonstrated that 17-AAG exerts its pro-degradative activity on mutant ARpolyQ without impacting on proteasome functions. 17-AAG removes ARpolyQ misfolded species and aggregates by activating the autophagic system. We next analyzed the 17-AAG effects on two proteins (SOD1 and TDP-43) involved in related motorneuronal diseases, such as amyotrophic lateral sclerosis (ALS). In these models 17-AAG was unable to counteract protein aggregation. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Polyploid tumour cells elicit paradiploid progeny through depolyploidizing divisions and regulated autophagic degradation.

    Science.gov (United States)

    Erenpreisa, Jekaterina; Salmina, Kristine; Huna, Anda; Kosmacek, Elizabeth A; Cragg, Mark S; Ianzini, Fiorenza; Anisimov, Alim P

    2011-07-01

    'Neosis' describes the process whereby p53 function-deficient tumour cells undergo self-renewal after genotoxic damage apparently via senescing ETCs (endopolyploid tumour cells). We previously reported that autophagic digestion and extrusion of DNA occurs in ETC and subsequently revealed that self-renewal transcription factors are also activated under these conditions. Here, we further studied this phenomenon in a range of cell lines after genotoxic damage induced by gamma irradiation, ETO (etoposide) or PXT (paclitaxel) treatment. These experiments revealed that chromatin degradation by autophagy was compatible with continuing mitotic activity in ETC. While the actively polyploidizing primary ETC produced early after genotoxic insult activated self-renewal factors throughout the polygenome, the secondary ETC restored after failed multipolar mitosis underwent subnuclei differentiation. As such, only a subset of subnuclei continued to express OCT4 and NANOG, while those lacking these factors stopped DNA replication and underwent degradation and elimination through autophagy. The surviving subnuclei sequestered nascent cytoplasm to form subcells, while being retained within the confines of the old ETC. Finally, the preformed paradiploid subcells became released from their linking chromosome bridges through autophagy and subsequently began cell divisions. These data show that 'neotic' ETC resulting from genotoxically damaged p53 function-deficient tumour cells develop through a heteronuclear system differentiating the polyploid genome into rejuvenated 'viable' subcells (which provide mitotically propagating paradiploid descendents) and subnuclei, which become degraded and eliminated by autophagy. The whole process reduces aneuploidy in descendants of ETC.

  20. Lung autophagic response following exposure of mice to whole body irradiation, with and without amifostine

    International Nuclear Information System (INIS)

    Zois, Christos E.; Giatromanolaki, Alexandra; Kainulainen, Heikki; Botaitis, Sotirios; Torvinen, Sira; Simopoulos, Constantinos; Kortsaris, Alexandros; Sivridis, Efthimios; Koukourakis, Michael I.

    2011-01-01

    Research highlights: → We investigated the effect 6 Gy of WBI on the autophagic machinery of normal mouse lung. → Irradiation induces dysfunction of the autophagic machinery in normal lung, characterized by decreased transcription of the LC3A/Beclin-1 mRNA and accumulation of the LC3A, and p62 proteins. → The membrane bound LC3A-II protein levels increased in the cytosolic fraction (not in the pellet), contrasting the patterns noted after starvation-induced autophagy. → Administration of amifostine, reversed all the LC3A and p62 findings, suggesting protection of the normal autophagic function. -- Abstract: Purpose: The effect of ionizing irradiation on the autophagic response of normal tissues is largely unexplored. Abnormal autophagic function may interfere the protein quality control leading to cell degeneration and dysfunction. This study investigates its effect on the autophagic machinery of normal mouse lung. Methods and materials: Mice were exposed to 6 Gy of whole body γ-radiation and sacrificed at various time points. The expression of MAP1LC3A/LC3A/Atg8, beclin-1, p62/sequestosome-1 and of the Bnip3 proteins was analyzed. Results: Following irradiation, the LC3A-I and LC3A-II protein levels increased significantly at 72 h and 7 days. Strikingly, LC3A-II protein was increased (5.6-fold at 7 days; p < 0.001) only in the cytosolic fraction, but remained unchanged in the membrane fraction. The p62 protein, was significantly increased in both supernatant and pellet fraction (p < 0.001), suggesting an autophagosome turnover deregulation. These findings contrast the patterns of starvation-induced autophagy up-regulation. Beclin-1 levels remained unchanged. The Bnip3 protein was significantly increased at 8 h, but it sharply decreased at 72 h (p < 0.05). Administration of amifostine (200 mg/kg), 30 min before irradiation, reversed all the LC3A and p62 findings on blots, suggesting restoration of the normal autophagic function. The LC3A and Beclin1 m

  1. Approximate error conjugation gradient minimization methods

    Science.gov (United States)

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  2. Conjugation chemistry through acetals toward a dextran-based delivery system for controlled release of siRNA

    KAUST Repository

    Cui, Lina

    2012-09-26

    New conjugation chemistry for polysaccharides, exemplified by dextran, was developed to enable the attachment of therapeutic or other functional moieties to the polysaccharide through cleavable acetal linkages. The acid-lability of the acetal groups allows the release of therapeutics under acidic conditions, such as that of the endocytic compartments of cells, regenerating the original free polysaccharide in the end. The physical and chemical behavior of these acetal groups can be adjusted by modifying their stereoelectronic and steric properties, thereby providing materials with tunable degradation and release rates. We have applied this conjugation chemistry in the development of water-soluble siRNA carriers, namely acetal-linked amino-dextrans, with various amine structures attached through either slow- or fast-degrading acetal linker. The carriers with the best combination of amine moieties and structural composition of acetals showed high in vitro transfection efficiency and low cytotoxicity in the delivery of siRNA. © 2012 American Chemical Society.

  3. Modelling conjugation with stochastic differential equations

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo; Hasman, Henrik

    2010-01-01

    Enterococcus faecium strains in a rich exhaustible media. The model contains a new expression for a substrate dependent conjugation rate. A maximum likelihood based method is used to estimate the model parameters. Different models including different noise structure for the system and observations are compared......Conjugation is an important mechanism involved in the transfer of resistance between bacteria. In this article a stochastic differential equation based model consisting of a continuous time state equation and a discrete time measurement equation is introduced to model growth and conjugation of two...... using a likelihood-ratio test and Akaike's information criterion. Experiments indicating conjugation on the agar plates selecting for transconjugants motivates the introduction of an extended model, for which conjugation on the agar plate is described in the measurement equation. This model is compared...

  4. The bifunctional autophagic flux by 2-deoxyglucose to control survival or growth of prostate cancer cells

    International Nuclear Information System (INIS)

    Jeon, Jeong Yong; Kim, Seung Won; Park, Ki Cheong; Yun, Mijin

    2015-01-01

    Recent reports using metabolism regulating drugs showed that nutrient deprivation was an efficient tool to suppress cancer progression. In addition, autophagy control is emerging to prevent cancer cell survival. Autophagy breaks down the unnecessary cytoplasmic components into anabolic units and energy sources, which are the most important sources for making the ATP that maintains homeostasis in cancer cell growth and survival. Therefore, the glucose analog 2-deoxyglucose (2DG) has been used as an anticancer reagent due to its inhibition of glycolysis. Prostate cancer cells (PC3) were treated with 2DG for 6 h or 48 h to analyze the changing of cell cycle and autophagic flux. Rapamycin and LC3B overexpressing vectors were administered to PC3 cells for autophagy induction and chloroquine and shBeclin1 plasmid were used to inhibit autophagy in PC3 cells to analyze PC3 cells growth and survival. The samples for western blotting were prepared in each culture condition to confirm the expression level of autophagy related and regulating proteins. We demonstrated that 2DG inhibits PC3 cells growth and had discriminating effects on autophagy regulation based on the different time period of 2DG treatment to control cell survival. Short-term treatment of 2DG induced autophagic flux, which increased microtubule associated protein 1 light chain 3B (LC3B) conversion rates and reduced p62 levels. However, 2DG induced autophagic flux is remarkably reduced over an extended time period of 2DG treatment for 48 h despite autophagy inducing internal signaling being maintained. The relationship between cell growth and autophagy was proved. Increased autophagic flux by rapamycin or LC3B overexpression powerfully reduced cell growth, while autophagy inhibition with shBeclin1 plasmid or chloroquine had no significant effect on regulating cell growth. Given these results, maintaining increased autophagic flux was more effective at inhibiting cancer cell progression than inhibition of

  5. Mild MPP+ exposure impairs autophagic degradation through a novel lysosomal acidity-independent mechanism.

    Science.gov (United States)

    Miyara, Masatsugu; Kotake, Yaichiro; Tokunaga, Wataru; Sanoh, Seigo; Ohta, Shigeru

    2016-10-01

    Parkinson's disease (PD) is the second most common neurodegenerative disorder, but its underlying cause remains unknown. Although recent studies using PD-related neurotoxin MPP + suggest autophagy involvement in the pathogenesis of PD, the effect of MPP + on autophagic processes under mild exposure, which mimics the slow progressive nature of PD, remains largely unclear. We examined the effect of mild MPP + exposure (10 and 200 μM for 48 h), which induces a more slowly developing cell death, on autophagic processes and the mechanistic differences with acute MPP + toxicity (2.5 and 5 mM for 24 h). In SH-SY5Y cells, mild MPP + exposure predominantly inhibited autophagosome degradation, whereas acute MPP + exposure inhibited both autophagosome degradation and basal autophagy. Mild MPP + exposure reduced lysosomal hydrolase cathepsin D activity without changing lysosomal acidity, whereas acute exposure decreased lysosomal density. Lysosome biogenesis enhancers trehalose and rapamycin partially alleviated mild MPP + exposure induced impaired autophagosome degradation and cell death, but did not prevent the pathogenic response to acute MPP + exposure, suggesting irreversible lysosomal damage. We demonstrated impaired autophagic degradation by MPP + exposure and mechanistic differences between mild and acute MPP + toxicities. Mild MPP + toxicity impaired autophagosome degradation through novel lysosomal acidity-independent mechanisms. Sustained mild lysosomal damage may contribute to PD. We examined the effects of MPP + on autophagic processes under mild exposure, which mimics the slow progressive nature of Parkinson's disease, in SH-SY5Y cells. This study demonstrated impaired autophagic degradation through a reduction in lysosomal cathepsin D activity without altering lysosomal acidity by mild MPP + exposure. Mechanistic differences between acute and mild MPP + toxicity were also observed. Sustained mild damage of lysosome may be an underlying cause of Parkinson

  6. A Possibility for Construction of an Iodine Cleaning System Based on Doping for π-Conjugated Polymers

    Directory of Open Access Journals (Sweden)

    Hiromasa Goto

    2011-05-01

    Full Text Available An iodine accumulation method using polyaniline (PANI and a textile composite is proposed. PANI/pulp paper sheets prepared by a paper making technique are suitable for iodine adsorption, because of good processability. The PANI-based paper sheets can be applied for iodine cleanup as air filters, water filters, and floorcloth. This concept may lead to a development of an iodine cleaning machine or iodine shield cloth based on π-conjugated polymer composites. In-situ vapor phase doping of iodine, observation of surface images, and IR measurements are carried out to examine iodine doping function for the PANI/pulp paper sheets.

  7. Electrochromic in conjugated polymers

    International Nuclear Information System (INIS)

    Picado Valenzuela, Alfredo

    2007-01-01

    This revision considered object the description of one of the materials with the greatest potential in the field of electrochromic (mainly in the visible region): the conjugated polymers (CP), area of enormous potential both now and in a short time ahead. The CP are insulating materials and organic semiconductors in a state not doped. They can be doped positively or negatively being observed a significant increase in the conductivity and being generated a color change in these materials. The understanding of how optical properties vary based on the chemical structure of the polymer or its mixtures and more precisely of the alternatives that can be entered into the conjugated system or π system to obtain a material that besides to be flexible, environmentally stable, presents the colored states. The revision was centred chiefly in the polypyrrole (Ppy), the polythiophene (PTh) and their derivatives such as poly (3.4-ethylenedioxythiophene) (PEDOT). The advantage of using monomers with variable structure, to adjust the composition of the copolymer, or to blend with the PC, allows to obtain a variety of colored states that can be modulated through the visible spectrum and even with applications to wavelengths outside of this region. Because the PC presented at least two different colored states can be varied continuously as a function of the voltage applied. In some cases, they may submit multicoloured statements, which offers a range of possibilities for their application in flexible electronic devices type screens and windows. Applications include smart windows, camouflage clothing and data screens. This type of material is emerging as one of the substitutes of the traditional inorganic semiconductor, with the advantage of its low cost, high flexibility and the possibility to generate multiple colors through the handling of the monomers in the structure and control of energy of his band gap. (author) [es

  8. Aging and Autophagic Function Influences the Progressive Decline of Adult Drosophila Behaviors.

    Directory of Open Access Journals (Sweden)

    Eric P Ratliff

    Full Text Available Multiple neurological disorders are characterized by the abnormal accumulation of protein aggregates and the progressive impairment of complex behaviors. Our Drosophila studies demonstrate that middle-aged wild-type flies (WT, ~4-weeks exhibit a marked accumulation of neural aggregates that is commensurate with the decline of the autophagy pathway. However, enhancing autophagy via neuronal over-expression of Atg8a (Atg8a-OE reduces the age-dependent accumulation of aggregates. Here we assess basal locomotor activity profiles for single- and group-housed male and female WT flies and observed that only modest behavioral changes occurred by 4-weeks of age, with the noted exception of group-housed male flies. Male flies in same-sex social groups exhibit a progressive increase in nighttime activity. Infrared videos show aged group-housed males (4-weeks are engaged in extensive bouts of courtship during periods of darkness, which is partly repressed during lighted conditions. Together, these nighttime courtship behaviors were nearly absent in young WT flies and aged Atg8a-OE flies. Previous studies have indicated a regulatory role for olfaction in male courtship partner choice. Coincidently, the mRNA expression profiles of several olfactory genes decline with age in WT flies; however, they are maintained in age-matched Atg8a-OE flies. Together, these results suggest that middle-aged male flies develop impairments in olfaction, which could contribute to the dysregulation of courtship behaviors during dark time periods. Combined, our results demonstrate that as Drosophila age, they develop early behavior defects that are coordinate with protein aggregate accumulation in the nervous system. In addition, the nighttime activity behavior is preserved when neuronal autophagy is maintained (Atg8a-OE flies. Thus, environmental or genetic factors that modify autophagic capacity could have a positive impact on neuronal aging and complex behaviors.

  9. A Founder Mutation in VPS11 Causes an Autosomal Recessive Leukoencephalopathy Linked to Autophagic Defects.

    Directory of Open Access Journals (Sweden)

    Jinglan Zhang

    2016-04-01

    Full Text Available Genetic leukoencephalopathies (gLEs are a group of heterogeneous disorders with white matter abnormalities affecting the central nervous system (CNS. The causative mutation in ~50% of gLEs is unknown. Using whole exome sequencing (WES, we identified homozygosity for a missense variant, VPS11: c.2536T>G (p.C846G, as the genetic cause of a leukoencephalopathy syndrome in five individuals from three unrelated Ashkenazi Jewish (AJ families. All five patients exhibited highly concordant disease progression characterized by infantile onset leukoencephalopathy with brain white matter abnormalities, severe motor impairment, cortical blindness, intellectual disability, and seizures. The carrier frequency of the VPS11: c.2536T>G variant is 1:250 in the AJ population (n = 2,026. VPS11 protein is a core component of HOPS (homotypic fusion and protein sorting and CORVET (class C core vacuole/endosome tethering protein complexes involved in membrane trafficking and fusion of the lysosomes and endosomes. The cysteine 846 resides in an evolutionarily conserved cysteine-rich RING-H2 domain in carboxyl terminal regions of VPS11 proteins. Our data shows that the C846G mutation causes aberrant ubiquitination and accelerated turnover of VPS11 protein as well as compromised VPS11-VPS18 complex assembly, suggesting a loss of function in the mutant protein. Reduced VPS11 expression leads to an impaired autophagic activity in human cells. Importantly, zebrafish harboring a vps11 mutation with truncated RING-H2 domain demonstrated a significant reduction in CNS myelination following extensive neuronal death in the hindbrain and midbrain. Thus, our study reveals a defect in VPS11 as the underlying etiology for an autosomal recessive leukoencephalopathy disorder associated with a dysfunctional autophagy-lysosome trafficking pathway.

  10. Conjugated polymer with carboxylate groups-Hg2 + system as a turn-on fluorescence probe for label-free detection of cysteine-containing compounds

    Science.gov (United States)

    Mi, Hongyu; Guan, Mingming; Liu, Jilin; Shan, Hongyan; Fei, Qiang; Huan, Yanfu; Feng, Guodong

    2017-04-01

    In this work, a turn on fluorescent sensor, based on Hg2 + coordination conjugated polymer, was developed to detect cysteine-containing compounds. The fluorescence of conjugated polymer (poly(2,5-bis (sodium 4-oxybutyrate) -1,4 - phenylethynylene-alt-1,4-phenyleneethynylene; PPE-OBS) would be quenched by Hg2 + because of the coordination-induced aggregation and electron transfers of PPE-OBS toward Hg2 +. When there were some cysteine-containing compounds in PPE-OBS-Hg2 + system, the fluorescence of PPE-OBS would be recovered. It indicated that the PPE-OBS-Hg2 + system could be used to detect cysteine-containing compounds. Under the optimized conditions, the experiment results showed that there were particularly linear range, high sensitivity and selectivity over other amino acids. The limit of detection (LOD) of cysteine (Cys), homocysteine (Hcy) and glutathione (GSH) were 0.725 μmol L- 1, 0.982 μmol L- 1 and 1.21 μmol L- 1 by using this sensor. In addition, Cys standard recovery in several green tea drink and honey samples was also demonstrated. The recovery of Cys was range from 96.3 to 105.0% and RSD was less than 3.25%. The satisfactory results demonstrated that the proposed method could be as a potential fluorescent method for determining cysteine-containing compounds in real samples.

  11. Optical phase conjugation

    CERN Document Server

    Fisher, Robert A

    1983-01-01

    This book appears at a time of intense activity in optical phase conjugation. We chose not to await the maturation of the field, but instead to provide this material in time to be useful in its development. We have tried very hard to elucidate and interrelate the various nonlinear phenomena which can be used for optical phase conjugation.

  12. The application of pH-sensitive fluorescent dyes in lactic acid bacteria reveals distinct extrusion systems for unmodified and conjugated dyes.

    Science.gov (United States)

    Glaasker, E; Konings, W N; Poolman, B

    1996-01-01

    Intracellular pH in bacteria can be measured efficiently between internal pH values of 6.5 and 8.5 with the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5[and-6]-carboxyfluorescein (BCECF). A new fluorescent pH probe with a lower pKa(app) than BCECF was synthesized from fluorescein isothiocyanate and glutamate. The new probe, N-(fluorescein thio-ureanyl)-glutamate (FTUG), was much less sensitive to changes in concentrations of KCl than was BCECF. Similar to BCECF, an efflux of FTUG independent of the proton motive force, but dependent on ATP, was observed both in Lactobacillus plantarum and Lactococcus lactis. Corrections for probe efflux allowed accurate measurements of the pHin. Similar intracellular pH values were determined with FTUG and BCECF, in the range where both probes can be applied, and the pH values correlated well with those estimated from the distribution of radio-labelled benzoic acid. Since FITC can easily be coupled to substrates containing an amino group, it is possible to develop other FITC derivatives as well. The mechanisms of probe excretion and the nature of the excreted product(s) were studied in further detail for BCECF and FTUG. BCECF was excreted from wild-type L. lactis in an unmodified form as was determined by chromatographic and mass spectrometry analysis. In the case of FTUG, the excreted product was a conjugated derivative. Unmodified FTUG was not excreted, although it was present in cellular extracts from L. lactis. Exit of BCECF was completely inhibited in a BCECF efflux mutant (Bef-) of L. lactis, whereas FTUG-conjugate efflux in this mutant was similar to the wild-type. Addition of indomethacin, a known inhibitor of BCECF efflux in human epithelial cells, resulted in complete inhibition of BCECF efflux in wild-type L. lactis, whereas FTUG-conjugate exit was only slightly affected. The results of the mutant and inhibitor studies suggest that FTUG-conjugate and BCECF efflux in L. lactis are mediated by different ATP

  13. Propofol prevents autophagic cell death following oxygen and glucose deprivation in PC12 cells and cerebral ischemia-reperfusion injury in rats.

    Directory of Open Access Journals (Sweden)

    Derong Cui

    Full Text Available Propofol exerts protective effects on neuronal cells, in part through the inhibition of programmed cell death. Autophagic cell death is a type of programmed cell death that plays elusive roles in controlling neuronal damage and metabolic homeostasis. We therefore studied whether propofol could attenuate the formation of autophagosomes, and if so, whether the inhibition of autophagic cell death mediates the neuroprotective effects observed with propofol.The cell model was established by depriving the cells of oxygen and glucose (OGD for 6 hours, and the rat model of ischemia was introduced by a transient two-vessel occlusion for 10 minutes. Transmission electron microscopy (TEM revealed that the formation of autophagosomes and autolysosomes in both neuronal PC12 cells and pyramidal rat hippocampal neurons after respective OGD and ischemia/reperfusion (I/R insults. A western blot analysis revealed that the autophagy-related proteins, such as microtubule-associated protein 1 light chain 3 (LC3-II, Beclin-1 and class III PI3K, were also increased accordingly, but cytoprotective Bcl-2 protein was decreased. The negative effects of OGD and I/R, including the formation of autophagosomes and autolysosomes, the increase in LC3-II, Beclin-1 and class III PI3K expression and the decline in Bcl-2 production were all inhibited by propofol and specific inhibitors of autophagy, such as 3-methyladenine (3-MA, LY294002 and Bafilomycin A1 (Baf,. Furthermore, in vitro OGD cultures and in vivo I/R rats showed an increase in cell survival following the administration of propofol, as assessed by an MTT assay or histochemical analyses.Our data suggest that propofol can markedly attenuate autophagic processes via the decreased expression of autophagy-related proteins in vitro and in vivo. This inhibition improves cell survival, which provides a novel explanation for the pleiotropic effects of propofol that benefit the nervous system.

  14. Monitoring protein turnover during phosphate starvation-dependent autophagic degradation using a photoconvertible fluorescent protein aggregate in tobacco BY-2 cells.

    Science.gov (United States)

    Tasaki, Maiko; Asatsuma, Satoru; Matsuoka, Ken

    2014-01-01

    We have developed a system for quantitative monitoring of autophagic degradation in transformed tobacco BY-2 cells using an aggregate-prone protein comprised of cytochrome b5 (Cyt b5) and a tetrameric red fluorescent protein (RFP). Unfortunately, this system is of limited use for monitoring the kinetics of autophagic degradation because the proteins synthesized before and after induction of autophagy cannot be distinguished. To overcome this problem, we developed a system using kikume green-red (KikGR), a photoconvertible and tetrameric fluorescent protein that changes its fluorescence from green to red upon irradiation with purple light. Using the fusion protein of Cyt b5 and KikGR together with a method for the bulk conversion of KikGR, which we had previously used to convert the Golgi-localized monomeric KikGR fusion protein, we were able to monitor both the growth and de novo formation of aggregates. Using this system, we found that tobacco cells do not cease protein synthesis under conditions of phosphate (Pi)-starvation. Induction of autophagy under Pi-starvation, but not under sugar- or nitrogen-starvation, was specifically inhibited by phosphite, which is an analog of Pi with a different oxidation number. Therefore, the mechanism by which BY-2 cells can sense Pi-starvation and induce autophagy does not involve sensing a general decrease in energy supply and a specific Pi sensor might be involved in the induction of autophagy under Pi-starvation.

  15. Relationship between symmetry of porphyrinic pi-conjugated systems and singlet oxygen (1Delta g) yields: low-symmetry tetraazaporphyrin derivatives.

    Science.gov (United States)

    Ishii, Kazuyuki; Itoya, Hatsumi; Miwa, Hideya; Fujitsuka, Mamoru; Ito, Osamu; Kobayashi, Nagao

    2005-07-07

    We have investigated the excited-state properties and singlet oxygen ((1)Delta(g)) generation mechanism in phthalocyanines (4M; M = H(2), Mg, or Zn) and in low-symmetry metal-free, magnesium, and zinc tetraazaporphyrins (TAPs), that is, monobenzo-substituted (1M), adjacently dibenzo-substituted (2AdM), oppositely dibenzo-substituted (2OpM), and tribenzo-substituted (3M) TAP derivatives, whose pi conjugated systems were altered by fusing benzo rings. The S(1)(x) and S(1)(y) states (these lowest excited singlet states are degenerate in D(4)(h) symmetry) split in the low-symmetry TAP derivatives. The excited-state energies were quantitatively determined from the electronic absorption spectra. The lowest excited triplet (T(1)(x)) energies were also determined from phosphorescence spectra, while the second lowest excited triplet (T(1)(y)) states were evaluated by using the energy splitting between the T(1)(x) and T(1)(y) states previously reported (Miwa, H.; Ishii, K.; Kobayashi, N. Chem. Eur. J. 2004, 10, 4422-4435). The singlet oxygen quantum yields (Phi(Delta)) are strongly dependent on the pi conjugated system. In particular, while the Phi(Delta) value of 2AdH(2) is smallest in our system, that of 2OpH(2), an isomer of 2AdH(2), is larger than that of 4Zn, in contrast to the heavy atom effect. The relationship between the molecular structure and Phi(Delta) values can be transformed into a relationship between the S(1)(x) --> T(1)(y) intersystem crossing rate constant (k(ISC)) and the energy difference between the S(1)(x) and T(1)(y) states (DeltaE(S)(x)(T)(y)). In each of the Zn, Mg, and metal-free compounds, the Phi(Delta)/tau(F) values (tau(F): fluorescence lifetime), which are related to the k(ISC) values, are proportional to exp(-DeltaE(S)(x)(T)(y)), indicating that singlet oxygen ((1)Delta(g)) is produced via the T(1)(y) state and that the S(1)(x) --> T(1)(y) ISC process follows the energy-gap law. From the viewpoint of photodynamic therapy, our methodology

  16. Soluble polymer conjugates for drug delivery.

    Science.gov (United States)

    Minko, Tamara

    2005-01-01

    The use of water-soluble polymeric conjugates as drug carriers offers several possible advantages. These advantages include: (1) improved drug pharmacokinetics; (2) decreased toxicity to healthy organs; (3) possible facilitation of accumulation and preferential uptake by targeted cells; (4) programmed profile of drug release. In this review, we will consider the main types of useful polymeric conjugates and their role and effectiveness as carriers in drug delivery systems.: © 2005 Elsevier Ltd . All rights reserved.

  17. Normal autophagic activity in macrophages from mice lacking Gαi3, AGS3, or RGS19.

    Directory of Open Access Journals (Sweden)

    Ali Vural

    Full Text Available In macrophages autophagy assists antigen presentation, affects cytokine release, and promotes intracellular pathogen elimination. In some cells autophagy is modulated by a signaling pathway that employs Gαi3, Activator of G-protein Signaling-3 (AGS3/GPSM1, and Regulator of G-protein Signaling 19 (RGS19. As macrophages express each of these proteins, we tested their importance in regulating macrophage autophagy. We assessed LC3 processing and the formation of LC3 puncta in bone marrow derived macrophages prepared from wild type, Gnai3(-/-, Gpsm1(-/-, or Rgs19(-/- mice following amino acid starvation or Nigericin treatment. In addition, we evaluated rapamycin-induced autophagic proteolysis rates by long-lived protein degradation assays and anti-autophagic action after rapamycin induction in wild type, Gnai3(-/-, and Gpsm1(-/- macrophages. In similar assays we compared macrophages treated or not with pertussis toxin, an inhibitor of GPCR (G-protein couple receptor triggered Gαi nucleotide exchange. Despite previous findings, the level of basal autophagy, autophagic induction, autophagic flux, autophagic degradation and the anti-autophagic action in macrophages that lacked Gαi3, AGS3, or RGS19; or had been treated with pertussis toxin, were similar to controls. These results indicate that while Gαi signaling may impact autophagy in some cell types it does not in macrophages.

  18. The BlcC (AttM) lactonase of Agrobacterium tumefaciens does not quench the quorum-sensing system that regulates Ti plasmid conjugative transfer.

    Science.gov (United States)

    Khan, Sharik R; Farrand, Stephen K

    2009-02-01

    The conjugative transfer of Agrobacterium plasmids is controlled by a quorum-sensing system consisting of TraR and its acyl-homoserine lactone (HSL) ligand. The acyl-HSL is essential for the TraR-mediated activation of the Ti plasmid Tra genes. Strains A6 and C58 of Agrobacterium tumefaciens produce a lactonase, BlcC (AttM), that can degrade the quormone, leading some to conclude that the enzyme quenches the quorum-sensing system. We tested this hypothesis by examining the effects of the mutation, induction, or mutational derepression of blcC on the accumulation of acyl-HSL and on the conjugative competence of strain C58. The induction of blc resulted in an 8- to 10-fold decrease in levels of extracellular acyl-HSL but in only a twofold decrease in intracellular quormone levels, a measure of the amount of active intracellular TraR. The induction or mutational derepression of blc as well as a null mutation in blcC had no significant effect on the induction of or continued transfer of pTiC58 from donors in any stage of growth, including stationary phase. In matings performed in developing tumors, wild-type C58 transferred the Ti plasmid to recipients, yielding transconjugants by 14 to 21 days following infection. blcC-null donors yielded transconjugants 1 week earlier, but by the following week, transconjugants were recovered at numbers indistinguishable from those of the wild type. Donors mutationally derepressed for blcC yielded transconjugants in planta at numbers 10-fold lower than those for the wild type at weeks 2 and 3, but by week 4, the two donors showed no difference in recoverable transconjugants. We conclude that BlcC has no biologically significant effect on Ti plasmid transfer or its regulatory system.

  19. Co-conjugation vis-à-vis individual conjugation of α-amylase and glucoamylase for hydrolysis of starch.

    Science.gov (United States)

    Jadhav, Swati B; Singhal, Rekha S

    2013-10-15

    Two enzymes, α-amylase and glucoamylase have been individually and co-conjugated to pectin by covalent binding. Both the enzyme systems showed better thermal and pH stability over the free enzyme system with the complete retention of original activities. Mixture of individually conjugated enzymes showed lower inactivation rate constant with longer half life than the co-conjugated enzyme system. Individually conjugated enzymes showed an increase of 56.48 kJ/mole and 38.22 kJ/mole in activation energy for denaturation than the free enzymes and co-conjugated enzymes, respectively. Km as well as Vmax of individually and co-conjugated enzymes was found to be higher than the free enzymes. SDS-polyacrylamide gel electrophoresis confirmed the formation of conjugate and co-conjugate as evident by increased molecular weight. Both the enzyme systems were used for starch hydrolysis where individually conjugated enzymes showed highest release of glucose at 60 °C and pH 5.0 as compared to free and co-conjugated enzyme. Copyright © 2013 Elsevier Ltd. All rights reserved.

  20. Modulation of apoptosis sensitivity through the interplay with autophagic and proteasomal degradation pathways

    Science.gov (United States)

    Delgado, M E; Dyck, L; Laussmann, M A; Rehm, M

    2014-01-01

    Autophagic and proteasomal degradation constitute the major cellular proteolysis pathways. Their physiological and pathophysiological adaptation and perturbation modulates the relative abundance of apoptosis-transducing proteins and thereby can positively or negatively adjust cell death susceptibility. In addition to balancing protein expression amounts, components of the autophagic and proteasomal degradation machineries directly interact with and co-regulate apoptosis signal transduction. The influence of autophagic and proteasomal activity on apoptosis susceptibility is now rapidly gaining more attention as a significant modulator of cell death signalling in the context of human health and disease. Here we present a concise and critical overview of the latest knowledge on the molecular interplay between apoptosis signalling, autophagy and proteasomal protein degradation. We highlight that these three pathways constitute an intricate signalling triangle that can govern and modulate cell fate decisions between death and survival. Owing to rapid research progress in recent years, it is now possible to provide detailed insight into the mechanisms of pathway crosstalk, common signalling nodes and the role of multi-functional proteins in co-regulating both protein degradation and cell death. PMID:24457955

  1. Sodium nitroprusside induces autophagic cell death in glutathione-depleted osteoblasts.

    Science.gov (United States)

    Son, Min Jeong; Lee, Seong-Beom; Byun, Yu Jeong; Lee, Hwa Ok; Kim, Ho-Shik; Kwon, Oh-Joo; Jeong, Seong-Whan

    2010-01-01

    Previous studies reported that high levels of nitric oxide (NO) induce apoptotic cell death in osteoblasts. We examined molecular mechanisms of cytotoxic injury induced by sodium nitroprusside (SNP), a NO donor, in both glutathione (GSH)-depleted and control U2-OS osteoblasts. Cell viability was reduced by much lower effective concentrations of SNP in GSH-depleted cells compared to normal cells. The data suggest that the level of intracellular GSH is critical in SNP-induced cell death processes of osteoblasts. The level of oxidative stress due to SNP treatments doubled in GSH-depleted cells when measured with fluorochrome H2DCFDA. Pretreatment with the NO scavenger PTIO preserved the viability of cells treated with SNP. Viability of cells treated with SNP was recovered by pretreatment with Wortmannin, an autophagy inhibitor, but not by pretreatment with zVAD-fmk, a pan-specific caspase inhibitor. Large increases of LC3-II were shown by immunoblot analysis of the SNP-treated cells, and the increase was blocked by pretreatment with PTIO or Wortmannin; this implies that under GSH-depleted conditions SNP induces different molecular signaling that lead to autophagic cell death. The ultrastructural morphology of SNP-treated cells in transmission electron microscopy showed numerous autophagic vacuoles. These data suggest NO produces oxidative stress and cellular damage that culminate in autophagic cell death of GSH-depleted osteoblasts. Copyright 2010 Wiley Periodicals, Inc.

  2. Qualidade conjugal: mapeando conceitos

    Directory of Open Access Journals (Sweden)

    Clarisse Mosmann

    2006-12-01

    Full Text Available Apesar da ampla utilização do conceito de qualidade conjugal, identifica-se falta de clareza conceitual acerca das variáveis que o compõem. Esse artigo apresenta revisão da literatura na área com o objetivo de mapear o conceito de qualidade conjugal. Foram analisadas sete principais teorias sobre o tema: Troca Social, Comportamental, Apego, Teoria da Crise, Interacionismo Simbólico. Pelos postulados propostos nas diferentes teorias, podem-se identificar três grupos de variáveis fundamentais na definição da qualidade conjugal: recursos pessoais dos cônjuges, contexto de inserção do casal e processos adaptativos. Neste sentido, a qualidade conjugal é resultado do processo dinâmico e interativo do casal, razão deste caráter multidimensional.

  3. Conjugate Gaze Palsies

    Science.gov (United States)

    ... version Home Brain, Spinal Cord, and Nerve Disorders Cranial Nerve Disorders Conjugate Gaze Palsies Horizontal gaze palsy Vertical ... Version. DOCTORS: Click here for the Professional Version Cranial Nerve Disorders Overview of the Cranial Nerves Internuclear Ophthalmoplegia ...

  4. Conjugated Polymer Solar Cells

    National Research Council Canada - National Science Library

    Paraschuk, Dmitry Y

    2006-01-01

    This report results from a contract tasking Moscow State University as follows: Conjugated polymers are promising materials for many photonics applications, in particular, for photovoltaic and solar cell devices...

  5. Polymers for Protein Conjugation

    Directory of Open Access Journals (Sweden)

    Gianfranco Pasut

    2014-01-01

    Full Text Available Polyethylene glycol (PEG at the moment is considered the leading polymer for protein conjugation in view of its unique properties, as well as to its low toxicity in humans, qualities which have been confirmed by its extensive use in clinical practice. Other polymers that are safe, biodegradable and custom-designed have, nevertheless, also been investigated as potential candidates for protein conjugation. This review will focus on natural polymers and synthetic linear polymers that have been used for protein delivery and the results associated with their use. Genetic fusion approaches for the preparation of protein-polypeptide conjugates will be also reviewed and compared with the best known chemical conjugation ones.

  6. Compensation of nonlinearity in a fiber-optic transmission system using frequency-degenerate phase conjugation through counter-propagating dual pump FWM in a semiconductor optical amplifier

    Science.gov (United States)

    Anchal, Abhishek; K, Pradeep Kumar; O'Duill, Sean; Anandarajah, Prince M.; Landais, Pascal

    2018-04-01

    We present a scheme of frequency-degenerate mid-span spectral inversion (MSSI) for nonlinearity compensation in fiber-optic transmission systems. The spectral inversion is obtained by using counter-propagating dual pump four-wave mixing in a semiconductor optical amplifier (SOA). Frequency-degeneracy between signal and conjugate is achieved by keeping two pump frequencies symmetrical about the signal frequency. We simulate the performance of MSSI for nonlinearity compensation by scrutinizing the improvement of the Q-factor of a 200 Gbps QPSK signal transmitted over a standard single mode fiber, as a function of launch power for different span lengths and number of spans. We demonstrate a 7.5 dB improvement in the input power dynamic range and an almost 83% increase in the transmission length for optimum MSSI parameters of -2 dBm pump power and 400 mA SOA current.

  7. Inhibition of mTOR improves the impairment of acidification in autophagic vesicles caused by hepatic steatosis

    International Nuclear Information System (INIS)

    Nakadera, Eisuke; Yamashina, Shunhei; Izumi, Kousuke; Inami, Yoshihiro; Sato, Toshifumi; Fukushima, Hirofumi; Kon, Kazuyoshi; Ikejima, Kenichi; Ueno, Takashi; Watanabe, Sumio

    2016-01-01

    Recent investigations revealed that dysfunction of autophagy involved in the progression of chronic liver diseases such as alcoholic and nonalcoholic steatohepatitis and hepatocellular neoplasia. Previously, it was reported that hepatic steatosis disturbs autophagic proteolysis via suppression of both autophagic induction and lysosomal function. Here, we demonstrate that autophagic acidification was altered by a decrease in lysosomal proton pump vacuolar-ATPase (V-ATPase) in steatohepatitis. The number of autophagic vesicles was increased in hepatocytes from obese KKAy mice as compared to control. Similarly, autophagic membrane protein LC3-II and lysosomal protein LAMP-2 expression were enhanced in KKAy mice liver. Nevertheless, both phospho-mTOR and p62 expression were augmented in KKAy mice liver. More than 70% of autophagosomes were stained by LysoTracker Red (LTR) in hepatocytes from control mice; however, the percentage of acidic autolysosomes was decreased in hepatocytes from KKAy mice significantly (40.1 ± 3.48%). Both protein and RNA level of V-ATPase subunits ATP6v1a, ATP6v1b, ATP6v1d in isolated lysosomes were suppressed in KKAy mice as compared to control. Interestingly, incubation with mTOR inhibitor rapamycin increased in the rate of LTR-positive autolysosomes in hepatocytes from KKAy mice and suppressed p62 accumulation in the liver from KKAy mice which correlated to an increase in the V-ATPase subunits expression. These results indicate that down-regulation of V-ATPase due to hepatic steatosis causes autophagic dysfunction via disruption of lysosomal and autophagic acidification. Moreover, activation of mTOR plays a pivotal role on dysregulation of lysosomal and autophagic acidification by modulation of V-ATPase expression and could therefore be a useful therapeutic target to ameliorate dysfunction of autophagy in NAFLD. - Highlights: • Hepatic steatosis causes accumulation of autophagic vesicles in hepatocytes. • Hepatic steatosis disturbs

  8. Inhibition of mTOR improves the impairment of acidification in autophagic vesicles caused by hepatic steatosis

    Energy Technology Data Exchange (ETDEWEB)

    Nakadera, Eisuke [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Yamashina, Shunhei, E-mail: syamashi@juntendo.ac.jp [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Izumi, Kousuke; Inami, Yoshihiro; Sato, Toshifumi; Fukushima, Hirofumi; Kon, Kazuyoshi; Ikejima, Kenichi [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Ueno, Takashi [Division of Proteomics and Biomolecular Science, Juntendo University, School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Watanabe, Sumio [Department of Gastroenterology, Juntendo University School of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2016-01-22

    Recent investigations revealed that dysfunction of autophagy involved in the progression of chronic liver diseases such as alcoholic and nonalcoholic steatohepatitis and hepatocellular neoplasia. Previously, it was reported that hepatic steatosis disturbs autophagic proteolysis via suppression of both autophagic induction and lysosomal function. Here, we demonstrate that autophagic acidification was altered by a decrease in lysosomal proton pump vacuolar-ATPase (V-ATPase) in steatohepatitis. The number of autophagic vesicles was increased in hepatocytes from obese KKAy mice as compared to control. Similarly, autophagic membrane protein LC3-II and lysosomal protein LAMP-2 expression were enhanced in KKAy mice liver. Nevertheless, both phospho-mTOR and p62 expression were augmented in KKAy mice liver. More than 70% of autophagosomes were stained by LysoTracker Red (LTR) in hepatocytes from control mice; however, the percentage of acidic autolysosomes was decreased in hepatocytes from KKAy mice significantly (40.1 ± 3.48%). Both protein and RNA level of V-ATPase subunits ATP6v1a, ATP6v1b, ATP6v1d in isolated lysosomes were suppressed in KKAy mice as compared to control. Interestingly, incubation with mTOR inhibitor rapamycin increased in the rate of LTR-positive autolysosomes in hepatocytes from KKAy mice and suppressed p62 accumulation in the liver from KKAy mice which correlated to an increase in the V-ATPase subunits expression. These results indicate that down-regulation of V-ATPase due to hepatic steatosis causes autophagic dysfunction via disruption of lysosomal and autophagic acidification. Moreover, activation of mTOR plays a pivotal role on dysregulation of lysosomal and autophagic acidification by modulation of V-ATPase expression and could therefore be a useful therapeutic target to ameliorate dysfunction of autophagy in NAFLD. - Highlights: • Hepatic steatosis causes accumulation of autophagic vesicles in hepatocytes. • Hepatic steatosis disturbs

  9. Design and operations of a load-tolerant external conjugate-T matching system for the A2 ICRH antennas at JET

    International Nuclear Information System (INIS)

    Monakhov, I.; Graham, M.; Blackman, T.; Dowson, S.; Durodie, F.; Jacquet, P.; Lehmann, J.; Mayoral, M.-L.; Nightingale, M.P.S.; Noble, C.; Sheikh, H.; Vrancken, M.; Walden, A.; Whitehurst, A.; Wooldridge, E.

    2013-01-01

    A load-tolerant external conjugate-T (ECT) impedance matching system for two A2 ion cyclotron resonance heating (ICRH) antennas was successfully put into operation at JET. The system allows continuous injection of the radio-frequency (RF) power into plasma in the presence of strong antenna loading perturbations caused by edge-localized modes (ELMs). Reliable ECT performance was demonstrated under a variety of antenna loading conditions including H-mode plasmas with radial outer gaps (ROGs) in the range 4–14 cm. The high resilience to ELMs predicted during the circuit simulations was fully confirmed experimentally. Dedicated arc-detection techniques and real-time matching algorithms were developed as a part of the ECT project. The new advanced wave amplitude comparison system has proven highly efficient in detection of arcs both between and during ELMs. The ECT system has allowed the delivery of up to 4 MW of RF power without trips into plasmas with type-I ELMs. Together with the 3 dB system and the ITER-like antenna, the ECT has brought the total RF power coupled to ELMy plasma to over 8 MW, considerably enhancing JET research capabilities. This paper provides an overview of the key design features of the ECT system and summarizes the main experimental results achieved so far. (paper)

  10. Depletion of the Third Complement Component Ameliorates Age-Dependent Oxidative Stress and Positively Modulates Autophagic Activity in Aged Retinas in a Mouse Model

    Directory of Open Access Journals (Sweden)

    Dorota Rogińska

    2017-01-01

    Full Text Available The aim of the study was to investigate the influence of complement component C3 global depletion on the biological structure and function of the aged retina. In vivo morphology (OCT, electrophysiological function (ERG, and the expression of selected oxidative stress-, apoptosis-, and autophagy-related proteins were assessed in retinas of 12-month-old C3-deficient and WT mice. Moreover, global gene expression in retinas was analyzed by RNA arrays. We found that the absence of active C3 was associated with (1 alleviation of the age-dependent decrease in retinal thickness and gradual deterioration of retinal bioelectrical function, (2 significantly higher levels of antioxidant enzymes (catalase and glutathione reductase and the antiapoptotic survivin and Mcl-1/Bak dimer, (3 lower expression of the cellular oxidative stress marker—4HNE—and decreased activity of proapoptotic caspase-3, (4 ameliorated retinal autophagic activity with localization of ubiquitinated protein conjugates commonly along the retinal pigment epithelium (RPE layer, and (5 significantly increased expression of several gene sets associated with maintenance of the physiological functions of the neural retina. Our findings shed light on mechanisms of age-related retinal alterations by identifying C3 as a potential therapeutic target for retinal aging.

  11. 8-C-(E-phenylethenyl)quercetin from onion/beef soup induces autophagic cell death in colon cancer cells through ERK activation.

    Science.gov (United States)

    Zhao, Yueliang; Fan, Daming; Zheng, Zong-Ping; Li, Edmund T S; Chen, Feng; Cheng, Ka-Wing; Wang, Mingfu

    2017-02-01

    Quercetin, a flavonoid, widely distributed in edible fruits and vegetables, was reported to effectively inhibit 2-amino-1-methyl-6-phenylimidazo[4, 5-b]pyridine (PhIP) formation in a food model (roast beef patties) with itself being converted into a novel compound 8-C-(E-phenylethenyl)quercetin (8-CEPQ). Here we investigated whether 8-CEPQ could be formed in a real food system, and tested its anticancer activity in human colon cancer cell lines. LC-MS was applied for the determination of 8-CEPQ formation in onion/beef soup. Anticancer activity of 8-CEPQ was evaluated by using cell viability assay and flow cytometry. Results showed that 8-CEPQ suppressed proliferation and caused G 2 phase arrest in colon cancer cells. Based on immunofluorescent staining assay, western blot assay, and RNA knockdown data, we found that 8-CEPQ did not cause apoptotic cell death. Instead, it induced autophagic cell death. Moreover, treatment with 8-CEPQ induced phosphorylation of extracellular signal-regulated kinase (ERK). Inhibition of ERK phosphorylation by the mitogen-activated protein kinase kinase (MEK)/ERK inhibitor U0126 attenuated 8-CEPQ-induced autophagy and reversed 8-CEPQ-mediated cell growth inhibition. Our results demonstrate that 8-CEPQ, a novel quercetin derivative, could be formed in onion/beef soup. 8-CEPQ inhibited colon cancer cell growth by inducing autophagic cell death through ERK activation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Dynamic autophagic activity affected the development of thoracic aortic dissection by regulating functional properties of smooth muscle cells

    International Nuclear Information System (INIS)

    Wang, Yang; Zhao, Zhi-Min; Zhang, Guan-Xin; Yang, Fan; Yan, Yan; Liu, Su-Xuan; Li, Song-Hua; Wang, Guo-Kun; Xu, Zhi-Yun

    2016-01-01

    The aortic medial degeneration is the key histopathologic feature of Thoracic aortic dissection (TAD). The aim of this study was to identify the change of autophagic activity in the aortic wall during TAD development, and to explore the roles of autophagy on regulating functional properties of smooth muscle cells (SMCs). Firstly, compared with control group (n = 11), the increased expression of autophagic markers Beclin1 and LC3 was detected in the aortic wall from TAD group (n = 23) by immunochemistry and western blot. We found that more autophagic vacuoles were present in the aortic wall of TAD patients using Transmission electron microscopy. Next, autophagic activity was examined in AD mice model established by β-aminopropionitrile fumarate (BAPN) and angiotensin II. Immunochemistry proved that autophagic activity was dynamically changed during AD development. Beclin1 and LC3 were detected up-regulated in the aortic wall in the second week after BAPN feeding, earlier than the fragmentation or loss of elastic fibers. When AD occurred in the 4th week, the expression of Beclin1 and LC3 began to decrease, but still higher than the control. Furthermore, autophagy was found to inhibit starvation-induced apoptosis of SMCs. Meanwhile, blockage of autophagy could suppress PDGF-induced phenotypic switch of SMCs. Taken together, autophagic activity was dynamically changed in the aortic wall during TAD development. The abnormal autophagy could regulate the functional properties of aortic SMCs, which might be the potential pathogenesis of TAD. - Highlights: • Autophagy is up-regulated in aorta wall from thoracic aorta dissection (TAD) patient. • Autophagic activity is dynamically changed during TAD development. • Dynamically change of autophagy is associated with pathological process of TAD. • Autophagy participate in the development of TAD by regulating function of SMCs.

  13. Fatty acid-amino acid conjugates are essential for systemic activation of salicylic acid-induced protein kinase and accumulation of jasmonic acid in Nicotiana attenuata.

    Science.gov (United States)

    Hettenhausen, Christian; Heinrich, Maria; Baldwin, Ian T; Wu, Jianqiang

    2014-11-28

    Herbivory induces the activation of mitogen-activated protein kinases (MAPKs), the accumulation of jasmonates and defensive metabolites in damaged leaves and in distal undamaged leaves. Previous studies mainly focused on individual responses and a limited number of systemic leaves, and more research is needed for a better understanding of how different plant parts respond to herbivory. In the wild tobacco Nicotiana attenuata, FACs (fatty acid-amino acid conjugates) in Manduca sexta oral secretions (OS) are the major elicitors that induce herbivory-specific signaling but their role in systemic signaling is largely unknown. Here, we show that simulated herbivory (adding M. sexta OS to fresh wounds) dramatically increased SIPK (salicylic acid-induced protein kinase) activity and jasmonic acid (JA) levels in damaged leaves and in certain (but not all) undamaged systemic leaves, whereas wounding alone had no detectable systemic effects; importantly, FACs and wounding are both required for activating these systemic responses. In contrast to the activation of SIPK and elevation of JA in specific systemic leaves, increases in the activity of an important anti-herbivore defense, trypsin proteinase inhibitor (TPI), were observed in all systemic leaves after simulated herbivory, suggesting that systemic TPI induction does not require SIPK activation and JA increases. Leaf ablation experiments demonstrated that within 10 minutes after simulated herbivory, a signal (or signals) was produced and transported out of the treated leaves, and subsequently activated systemic responses. Our results reveal that N. attenuata specifically recognizes herbivore-derived FACs in damaged leaves and rapidly send out a long-distance signal to phylotactically connected leaves to activate MAPK and JA signaling, and we propose that FACs that penetrated into wounds rapidly induce the production of another long-distance signal(s) which travels to all systemic leaves and activates TPI defense.

  14. New heparin–indomethacin conjugate with an ester linkage: Synthesis, self aggregation and drug delivery behavior

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nan-Nan; Zheng, Bing-Na [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Lin, Jian-Tao [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Guangdong Medical College, Dongguan 523808 (China); Zhang, Li-Ming, E-mail: ceszhlm@mail.sysu.edu.cn [DSAPM Lab and PCFM Lab, Institute of Polymer Science, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China)

    2014-01-01

    New heparin–indomethacin conjugate with an ester linkage was prepared by the carbodiimide-mediated condensation reaction, and then characterized by FTIR and {sup 1}HNMR analyses. Due to its amphiphilic character, such a conjugate could self-aggregate into spherical nanoparticles in aqueous system, as confirmed by fluorescence spectroscopy, dynamic light scattering and transmission electron microscopy. By the in vitro drug release tests, the resultant conjugate nanoparticles were found to have a sustained and esterase-sensitive release behavior for conjugated indomethacin. In addition, the uptake of these conjugate nanoparticles into human nasopharyngeal carcinoma CNE1 cells was confirmed by fluorescence microscopy. - Highlights: • New heparin–indomethacin conjugate with an ester linkage was prepared. • Such a conjugate could self-aggregate into spherical nanoparticles in aqueous system. • The resultant conjugate nanoparticles exhibited an esterase-sensitive drug release behavior. • The resultant conjugate nanoparticles showed the cellular uptake ability in CNE1 cells.

  15. Hyperthermia enhances radiosensitivity of colorectal cancer cells through ROS inducing autophagic cell death.

    Science.gov (United States)

    Ba, Ming-Chen; Long, Hui; Wang, Shuai; Wu, Yin-Bing; Zhang, Bo-Huo; Yan, Zhao-Fei; Yu, Fei-Hong; Cui, Shu-Zhong

    2018-04-01

    Hyperthermia (HT) enhances the anti-cancer effects of radiotherapy (RT), but the precise biochemical mechanisms involved are unclear. This study was aim to investigate if mild HT sensitizes colorectal cancer cells to RT through reactive oxygen species (ROS)-inducing autophagic cell death in a mice model of HCT116 human colorectal cancer. HCT116 mice model were randomly divided into five groups: mock group, hyperthermia group (HT), radiotherapy group (RT), HT + RT group, and HT + RT +N-acetyl L-cysteine (NAC) group (HT + CT + NAC). After four weeks of treatment, cancer growth inhibition, rate and mitochondrial membrane potential were measured with MTT and JC-1 assays, respectively, while ROS were estimated fluorimetrically. The relationship of these parameters to expressions of autophagy-related genes Beclin1, LC3B, and mTOR was analyzed. Gene expression was measured by Real-Time polymerase chain reaction (RT-PCR). There were significant increases in ROS levels and mitochondrial membrane potential in the HT + RT group. ROS levels in the HT + RT group increased more significantly than in any other group. In contrast, ROS levels in the HT + RT + NAC group were significantly decreased relative to the HT + RT group. The number of autophagic bodies in HT + RT group was higher than that of mock group. There were significant increases in the expression of Beclin1 and LC3B genes, while mTOR expression was significantly decreased in the HT + CT group. Treatment with NAC reversed the pattern of these changes. These results indicate that HT enhances the radiosensitivity of colorectal cancer cells to RT through ROS inducing autophagic cell death. © 2017 Wiley Periodicals, Inc.

  16. Interplay of alternative conjugated pathways and steric interactions on the electronic and optical properties of donor-acceptor conjugated polymers

    KAUST Repository

    Lima, Igo T.; Risko, Chad; Aziz, Saadullah Gary; Da Silva Filho, Demé trio A Da Silva; Bredas, Jean-Luc

    2014-01-01

    Donor-acceptor π-conjugated copolymers are of interest for a wide range of electronic applications, including field-effect transistors and solar cells. Here, we present a density functional theory (DFT) study of the impact of varying the conjugation pathway on the geometric, electronic, and optical properties of donor-acceptor systems. We consider both linear ("in series"), traditional conjugation among the donor-acceptor moieties versus structures where the acceptor units are appended orthogonally to the linear, donor-only conjugated backbone. Long-range-corrected hybrid functionals are used in the investigation with the values of the tuned long-range separation parameters providing an estimate of the extent of conjugation as a function of the oligomer architecture. Considerable differences in the electronic and optical properties are determined as a function of the nature of the conjugation pathway, features that should be taken into account in the design of donor-acceptor copolymers.

  17. Autophagic dysfunction in a lysosomal storage disorder due to impaired proteolysis.

    Science.gov (United States)

    Elrick, Matthew J; Lieberman, Andrew P

    2013-02-01

    Alterations in macroautophagy (hereafter referred to as "autophagy") are a common feature of lysosomal storage disorders, and have been hypothesized to play a major role in the pathogenesis of these diseases. We have recently reported multiple defects in autophagy contributing to the lysosomal storage disorder Niemann-Pick type C (NPC). These include increased formation of autophagosomes, slowed turnover of autophagosomes secondary to impaired lysosomal proteolysis, and delivery of stored lipids to the lysosome via autophagy. The study summarized here describes novel methods for the interrogation of individual stages of the autophagic pathway, and suggests mechanisms by which lipid storage may result in broader lysosomal dysfunction.

  18. Skeletal muscle myotubes of the severely obese exhibit altered ubiquitin-proteasome and autophagic/lysosomal proteolytic flux

    Science.gov (United States)

    Bollinger, Lance M.; Powell, Jonathan J. S.; Houmard, Joseph A.; Witczak, Carol A.; Brault, Jeffrey J.

    2015-01-01

    Objective Whole-body protein metabolism is dysregulated with obesity. Our goal was to determine if activity and expression of major protein degradation pathways are compromised specifically in human skeletal muscle with obesity. Methods We utilized primary Human Skeletal Muscle cell (HSkM) cultures since cellular mechanisms can be studied absent of hormones and contractile activity that could independently influence metabolism. HSkM from 10 lean (BMI ≤ 26.0 kg/m2) and 8 severely obese (BMI ≥ 39.0) women were examined basally and when stimulated to atrophy (serum and amino acid starvation). Results HSkM from obese donors had a lower proportion of type I myosin heavy chain and slower flux through the autophagic/lysosomal pathway. During starvation, flux through the ubiquitin-proteasome system diverged according to obesity status, with a decrease in the lean and an increase in HSkM from obese subjects. HSkMC from the obese also displayed elevated proteasome activity despite no difference in proteasome content. Atrophy-related gene expression and myotube area were similar in myotubes derived from lean and obese individuals under basal and starved conditions. Conclusions Our data indicate that muscle cells of the lean and severely obese have innate differences in management of protein degradation, which may explain their metabolic differences. PMID:26010327

  19. Dependence of the compensation error on the error of a sensor and corrector in an adaptive optics phase-conjugating system

    International Nuclear Information System (INIS)

    Kiyko, V V; Kislov, V I; Ofitserov, E N

    2015-01-01

    In the framework of a statistical model of an adaptive optics system (AOS) of phase conjugation, three algorithms based on an integrated mathematical approach are considered, each of them intended for minimisation of one of the following characteristics: the sensor error (in the case of an ideal corrector), the corrector error (in the case of ideal measurements) and the compensation error (with regard to discreteness and measurement noises and to incompleteness of a system of response functions of the corrector actuators). Functional and statistical relationships between the algorithms are studied and a relation is derived to ensure calculation of the mean-square compensation error as a function of the errors of the sensor and corrector with an accuracy better than 10%. Because in adjusting the AOS parameters, it is reasonable to proceed from the equality of the sensor and corrector errors, in the case the Hartmann sensor is used as a wavefront sensor, the required number of actuators in the absence of the noise component in the sensor error turns out 1.5 – 2.5 times less than the number of counts, and that difference grows with increasing measurement noise. (adaptive optics)

  20. Dependence of the compensation error on the error of a sensor and corrector in an adaptive optics phase-conjugating system

    Energy Technology Data Exchange (ETDEWEB)

    Kiyko, V V; Kislov, V I; Ofitserov, E N [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2015-08-31

    In the framework of a statistical model of an adaptive optics system (AOS) of phase conjugation, three algorithms based on an integrated mathematical approach are considered, each of them intended for minimisation of one of the following characteristics: the sensor error (in the case of an ideal corrector), the corrector error (in the case of ideal measurements) and the compensation error (with regard to discreteness and measurement noises and to incompleteness of a system of response functions of the corrector actuators). Functional and statistical relationships between the algorithms are studied and a relation is derived to ensure calculation of the mean-square compensation error as a function of the errors of the sensor and corrector with an accuracy better than 10%. Because in adjusting the AOS parameters, it is reasonable to proceed from the equality of the sensor and corrector errors, in the case the Hartmann sensor is used as a wavefront sensor, the required number of actuators in the absence of the noise component in the sensor error turns out 1.5 – 2.5 times less than the number of counts, and that difference grows with increasing measurement noise. (adaptive optics)

  1. Cathepsin E deficiency impairs autophagic proteolysis in macrophages.

    Directory of Open Access Journals (Sweden)

    Takayuki Tsukuba

    Full Text Available Cathepsin E is an endosomal aspartic proteinase that is predominantly expressed in immune-related cells. Recently, we showed that macrophages derived from cathepsin E-deficient (CatE(-/- mice display accumulation of lysosomal membrane proteins and abnormal membrane trafficking. In this study, we demonstrated that CatE(-/- macrophages exhibit abnormalities in autophagy, a bulk degradation system for aggregated proteins and damaged organelles. CatE(-/- macrophages showed increased accumulation of autophagy marker proteins such as LC3 and p62, and polyubiquitinated proteins. Cathepsin E deficiency also altered autophagy-related signaling pathways such as those mediated by the mammalian target of rapamycin (mTOR, Akt, and extracellular signal-related kinase (ERK. Furthermore, immunofluorescence microscopy analyses showed that LC3-positive vesicles were merged with acidic compartments in wild-type macrophages, but not in CatE(-/- macrophages, indicating inhibition of fusion of autophagosome with lysosomes in CatE(-/- cells. Delayed degradation of LC3 protein was also observed under starvation-induced conditions. Since the autophagy system is involved in the degradation of damaged mitochondria, we examined the accumulation of damaged mitochondria in CatE(-/- macrophages. Several mitochondrial abnormalities such as decreased intracellular ATP levels, depolarized mitochondrial membrane potential, and decreased mitochondrial oxygen consumption were observed. Such mitochondrial dysfunction likely led to the accompanying oxidative stress. In fact, CatE(-/- macrophages showed increased reactive oxygen species (ROS production and up-regulation of oxidized peroxiredoxin-6, but decreased antioxidant glutathione. These results indicate that cathepsin E deficiency causes autophagy impairment concomitantly with increased aberrant mitochondria as well as increased oxidative stress.

  2. Peptide-Carrier Conjugation

    DEFF Research Database (Denmark)

    Hansen, Paul Robert

    2015-01-01

    To produce antibodies against synthetic peptides it is necessary to couple them to a protein carrier. This chapter provides a nonspecialist overview of peptide-carrier conjugation. Furthermore, a protocol for coupling cysteine-containing peptides to bovine serum albumin is outlined....

  3. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2018-05-15

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  4. DNA-cell conjugates

    Science.gov (United States)

    Hsiao, Shih-Chia; Francis, Matthew B.; Bertozzi, Carolyn; Mathies, Richard; Chandra, Ravi; Douglas, Erik; Twite, Amy; Toriello, Nicholas; Onoe, Hiroaki

    2016-05-03

    The present invention provides conjugates of DNA and cells by linking the DNA to a native functional group on the cell surface. The cells can be without cell walls or can have cell walls. The modified cells can be linked to a substrate surface and used in assay or bioreactors.

  5. Stability of cytochromes P450 and phase II conjugation systems in precision-cut rat lung slices cultured up to 72 h.

    Science.gov (United States)

    Umachandran, Meera; Ioannides, Costas

    2006-07-05

    The objective of the present study was to evaluate the stability of cytochrome P450 enzymes and of the conjugation enzyme systems epoxide hydrolase, glucuronosyl transferase, sulphotransferase and glutathione S-transferase in precision-cut rat lung slices incubated in RPMI media for different time periods up to 72 h. Moreover, the effect of culturing of lung slices on total glutathione levels and glutathione reductase was also investigated. Monitoring of cytochrome P450 activity was achieved using established diagnostic probes, but when activity in the lung was low the maintenance of the various enzymes in culture was determined immunologically using Western blotting. The dealkylation of pentoxyresorufin declined markedly during the first 4h of incubation but in the case of ethoxyresorufin loss of activity was more gradual and less severe. Western blot analysis revealed that the rate of decrease in cytochrome P450 apoprotein levels was isoform-specific with CYP2E1 being the most stable and CYP3A the least stable. Generally, phase II activities, especially cytosolic sulphotransferase, were relatively more stable throughout the incubation period compared with cytochromes P450. Finally, glutathione reductase activity and total glutathione levels were maintained throughout the 72 h incubation. The present studies indicate that xenobiotic-metabolising enzymes in precision-cut rat lung slices decline in culture, but the rate of loss differs and depends on the nature of the enzyme.

  6. Immunization with the conjugate vaccine Vi-CRM₁₉₇ against Salmonella typhi induces Vi-specific mucosal and systemic immune responses in mice.

    Science.gov (United States)

    Fiorino, Fabio; Ciabattini, Annalisa; Rondini, Simona; Pozzi, Gianni; Martin, Laura B; Medaglini, Donata

    2012-09-21

    Typhoid fever is a public health problem, especially among young children in developing countries. To address this need, a glycoconjugate vaccine Vi-CRM₁₉₇, composed of the polysaccharide antigen Vi covalently conjugated to the non-toxic mutant of diphtheria toxin CRM₁₉₇, is under development. Here, we assessed the antibody and cellular responses, both local and systemic, following subcutaneous injection of Vi-CRM₁₉₇. The glycoconjugate elicited Vi-specific serum IgG titers significantly higher than unconjugated Vi, with prevalence of IgG1 that persisted for at least 60 days after immunization. Vi-specific IgG, but not IgA, were present in intestinal washes. Lymphocytes proliferation after restimulation with Vi-CRM₁₉₇ was observed in spleen and mesenteric lymph nodes. These data confirm the immunogenicity of Vi-CRM₁₉₇ and demonstrate that the vaccine-specific antibody and cellular immune responses are present also in the intestinal tract, thus strengthening the suitability of Vi-CRM₁₉₇ as a promising candidate vaccine against Salmonella Typhi. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Determination of catecholamine in human serum by a fluorescent quenching method based on a water-soluble fluorescent conjugated polymer-enzyme hybrid system.

    Science.gov (United States)

    Huang, Hui; Gao, Yuan; Shi, Fanping; Wang, Guannan; Shah, Syed Mazhar; Su, Xingguang

    2012-03-21

    In this paper, a sensitive water-soluble fluorescent conjugated polymer biosensor for catecholamine (dopamine DA, adrenaline AD and norepinephrine NE) was developed. In the presence of horse radish peroxidase (HRP) and H(2)O(2), catecholamine could be oxidized and the oxidation product of catecholamine could quench the photoluminescence (PL) intensity of poly(2,5-bis(3-sulfonatopropoxy)-1,4-phenylethynylenealt-1,4-poly(phenylene ethynylene)) (PPESO(3)). The quenching PL intensity of PPESO(3) (I(0)/I) was proportional to the concentration of DA, AD and NE in the concentration ranges of 5.0 × 10(-7) to 1.4 × 10(-4), 5.0 × 10(-6) to 5.0 × 10(-4), and 5.0 × 10(-6) to 5.0 × 10(-4) mol L(-1), respectively. The detection limit for DA, AD and NE was 1.4 × 10(-7) mol L(-1), 1.0 × 10(-6) and 1.0 × 10(-6) mol L(-1), respectively. The PPESO(3)-enzyme hybrid system based on the fluorescence quenching method was successfully applied for the determination of catecholamine in human serum samples with good accuracy and satisfactory recovery. The results were in good agreement with those provided by the HPLC-MS method.

  8. Vitamin K3 attenuates cerulein-induced acute pancreatitis through inhibition of the autophagic pathway.

    Science.gov (United States)

    Chinzei, Ryo; Masuda, Atsuhiro; Nishiumi, Shin; Nishida, Masayuki; Onoyama, Mitsuko; Sanuki, Tsuyoshi; Fujita, Tsuyoshi; Moritoh, Satoshi; Itoh, Tomoo; Kutsumi, Hiromu; Mizuno, Shigeto; Azuma, Takeshi; Yoshida, Masaru

    2011-01-01

    The discovery of novel and effective treatment methods would be of great help to patients with acute pancreatitis. The aims of this study were to determine the inhibitory effects of vitamin K3 (VK3) against cerulein-induced acute pancreatitis in mice and to examine the mechanisms behind these effects. Acute pancreatitis in mice was induced by intraperitoneal injection of cerulein 6 times at hourly intervals. Vitamin K3 was administered once before the first injection of cerulein or twice before and after the first injection of cerulein. The degrees of inflammation and autophagy in the pancreatic tissue were estimated by histological examination, measurement of enzyme activity, confocal microscopy, and Western blotting. The inhibitory effects of VK3 against rapamycin-induced autophagy were also examined using HeLa cells stably expressing green fluorescent protein LC3. Cerulein-induced acute pancreatitis was markedly attenuated by the administration of VK3. In addition, VK3 led to the inhibition of cerulein-evoked autophagic changes and colocalization of autophagosomes and lysosomes in the pancreatic tissue. Vitamin K3 also reduced rapamycin-induced autophagy in HeLa/green fluorescent protein LC3 cells. Our data suggest that the administration of VK3 reduces pancreatic inflammation in acute pancreatitis through inhibition of the autophagic pathway. Vitamin K3 may be an effective therapeutic strategy against acute pancreatitis.

  9. Intermittent fasting is neuroprotective in focal cerebral ischemia by minimizing autophagic flux disturbance and inhibiting apoptosis.

    Science.gov (United States)

    Jeong, Ji Heun; Yu, Kwang Sik; Bak, Dong Ho; Lee, Je Hun; Lee, Nam Seob; Jeong, Young Gil; Kim, Dong Kwan; Kim, Jwa-Jin; Han, Seung-Yun

    2016-11-01

    Previous studies have demonstrated that autophagy induced by caloric restriction (CR) is neuroprotective against cerebral ischemia. However, it has not been determined whether intermittent fasting (IF), a variation of CR, can exert autophagy-related neuroprotection against cerebral ischemia. Therefore, the neuroprotective effect of IF was evaluated over the course of two weeks in a rat model of focal cerebral ischemia, which was induced by middle cerebral artery occlusion and reperfusion (MCAO/R). Specifically, the role of autophagy modulation as a potential underlying mechanism for this phenomenon was investigated. It was demonstrated that IF reduced infarct volume and brain edema, improved neurobehavioral deficits, and rescued neuronal loss after MCAO/R. Furthermore, neuronal apoptosis was decreased by IF in the rat cortex. An increase in the number of autophagosomes (APs) was demonstrated in the cortices of IF-treated rats, using immunofluorescence staining and transmission electron microscopy. Using immunoblots, an IF-induced increase was detected in microtubule-associated protein 1 light chain 3 (LC3)-II, Rab7, and cathepsin D protein levels, which corroborated previous morphological studies. Notably, IF reduced the accumulation of APs and p62, demonstrating that IF attenuated the MCAO/R-induced disturbance of autophagic flux in neurons. The findings of the present study suggest that IF-induced neuroprotection in focal cerebral ischemia is due, at least in part, to the minimization of autophagic flux disturbance and inhibition of apoptosis.

  10. Orphan nuclear receptor TR3 acts in autophagic cell death via mitochondrial signaling pathway.

    Science.gov (United States)

    Wang, Wei-jia; Wang, Yuan; Chen, Hang-zi; Xing, Yong-zhen; Li, Feng-wei; Zhang, Qian; Zhou, Bo; Zhang, Hong-kui; Zhang, Jie; Bian, Xue-li; Li, Li; Liu, Yuan; Zhao, Bi-xing; Chen, Yan; Wu, Rong; Li, An-zhong; Yao, Lu-ming; Chen, Ping; Zhang, Yi; Tian, Xu-yang; Beermann, Friedrich; Wu, Mian; Han, Jiahuai; Huang, Pei-qiang; Lin, Tianwei; Wu, Qiao

    2014-02-01

    Autophagy is linked to cell death, yet the associated mechanisms are largely undercharacterized. We discovered that melanoma, which is generally resistant to drug-induced apoptosis, can undergo autophagic cell death with the participation of orphan nuclear receptor TR3. A sequence of molecular events leading to cellular demise is launched by a specific chemical compound, 1-(3,4,5-trihydroxyphenyl)nonan-1-one, newly acquired from screening a library of TR3-targeting compounds. The autophagic cascade comprises TR3 translocation to mitochondria through interaction with the mitochondrial outer membrane protein Nix, crossing into the mitochondrial inner membrane through Tom40 and Tom70 channel proteins, dissipation of mitochondrial membrane potential by the permeability transition pore complex ANT1-VDAC1 and induction of autophagy. This process leads to excessive mitochondria clearance and irreversible cell death. It implicates a new approach to melanoma therapy through activation of a mitochondrial signaling pathway that integrates a nuclear receptor with autophagy for cell death.

  11. Hydrogen peroxide impairs autophagic flux in a cell model of nonalcoholic fatty liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Pengtao [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Shijingshan District, Beijing 100049 (China); Huang, Zhen [Department of Abdominal Surgical Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, 17 Panjiayuan Nanli, Chaoyang District, Beijing 100021 (China); Zhao, Hong, E-mail: zhaohong9@sina.com [Department of Abdominal Surgical Oncology, Cancer Hospital, Chinese Academy of Medical Sciences, 17 Panjiayuan Nanli, Chaoyang District, Beijing 100021 (China); Wei, Taotao, E-mail: weitt@moon.ibp.ac.cn [National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Chaoyang District, Beijing 100101 (China)

    2013-04-19

    Highlights: •Free fatty acids exposure induces elevated autophagy. •H{sub 2}O{sub 2} inhibits autophagic flux through impairing the fusion between autophagosomes and lysosomes. •Inhibition of autophagy potentiates H{sub 2}O{sub 2}-induced cell death. -- Abstract: Nonalcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, but the pathogenesis of NAFLD is not fully clear. The aim of this study was to determine whether autophagy plays a role in the pathogenesis of NAFLD. We found that the levels of autophagy were elevated in hepatoma cells upon exposure to free fatty acids, as confirmed by the increase in the number of autophagosomes. However, exposure of hepatoma cells to H{sub 2}O{sub 2} and TNF-α, two typical “second hit” factors, increased the initiation of autophagy but inhibited the autophagic flux. The inhibition of autophagy sensitized cells to pro-apoptotic stimuli. Taken together, our results suggest that autophagy acts as a protective mechanism in the pathogenesis of NAFLD and that impairment of autophagy might induce more severe lesions of the liver. These findings will be a benefit to the understanding of the pathogenesis of NAFLD and might suggest a strategy for the prevention and cure of NAFLD.

  12. Acid sphingomyelinase modulates the autophagic process by controlling lysosomal biogenesis in Alzheimer's disease.

    Science.gov (United States)

    Lee, Jong Kil; Jin, Hee Kyung; Park, Min Hee; Kim, Bo-ra; Lee, Phil Hyu; Nakauchi, Hiromitsu; Carter, Janet E; He, Xingxuan; Schuchman, Edward H; Bae, Jae-sung

    2014-07-28

    In Alzheimer's disease (AD), abnormal sphingolipid metabolism has been reported, although the pathogenic consequences of these changes have not been fully characterized. We show that acid sphingomyelinase (ASM) is increased in fibroblasts, brain, and/or plasma from patients with AD and in AD mice, leading to defective autophagic degradation due to lysosomal depletion. Partial genetic inhibition of ASM (ASM(+/-)) in a mouse model of familial AD (FAD; amyloid precursor protein [APP]/presenilin 1 [PS1]) ameliorated the autophagocytic defect by restoring lysosomal biogenesis, resulting in improved AD clinical and pathological findings, including reduction of amyloid-β (Aβ) deposition and improvement of memory impairment. Similar effects were noted after pharmacologic restoration of ASM to the normal range in APP/PS1 mice. Autophagic dysfunction in neurons derived from FAD patient induced pluripotent stem cells (iPSCs) was restored by partial ASM inhibition. Overall, these results reveal a novel mechanism of ASM pathogenesis in AD that leads to defective autophagy due to impaired lysosomal biogenesis and suggests that partial ASM inhibition is a potential new therapeutic intervention for the disease. © 2014 Lee et al.

  13. Akebia saponin PA induces autophagic and apoptotic cell death in AGS human gastric cancer cells.

    Science.gov (United States)

    Xu, Mei-Ying; Lee, Dong Hwa; Joo, Eun Ji; Son, Kun Ho; Kim, Yeong Shik

    2013-09-01

    In this study, we investigated the anticancer mechanism of akebia saponin PA (AS), a natural product isolated from Dipsacus asperoides in human gastric cancer cell lines. It was shown that AS-induced cell death is caused by autophagy and apoptosis in AGS cells. The apoptosis-inducing effect of AS was characterized by annexin V/propidium (PI) staining, increase of sub-G1 phase and caspase-3 activation, while the autophagy-inducing effect was indicated by the formation of cytoplasmic vacuoles and microtubule-associated protein 1 light chain-3 II (LC3-II) conversion. The autophagy inhibitor bafilomycin A1 (BaF1) decreased AS-induced cell death and caspase-3 activation, but caspase-3 inhibitor Ac-DEVD-CHO did not affect LC3-II accumulation or AS-induced cell viability, suggesting that AS induces autophagic cell death and autophagy contributes to caspase-3-dependent apoptosis. Furthermore, AS activated p38/c-Jun N-terminal kinase (JNK), which could be inhibited by BaF1, and caspase-3 activation was attenuated by both SB202190 and SP600125, indicating that AS-induced autophagy promotes mitogen-activated protein kinases (MAPKs)-mediated apoptosis. Taken together, these results demonstrate that AS induces autophagic and apoptotic cell death and autophagy plays the main role in akebia saponin PA-induced cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Fullerenol cytotoxicity in kidney cells is associated with cytoskeleton disruption, autophagic vacuole accumulation, and mitochondrial dysfunction

    International Nuclear Information System (INIS)

    Johnson-Lyles, Denise N.; Peifley, Kimberly; Lockett, Stephen; Neun, Barry W.; Hansen, Matthew; Clogston, Jeffrey; Stern, Stephan T.; McNeil, Scott E.

    2010-01-01

    Water soluble fullerenes, such as the hydroxylated fullerene, fullerenol (C 60 OH x ), are currently under development for diagnostic and therapeutic biomedical applications in the field of nanotechnology. These molecules have been shown to undergo urinary clearance, yet there is limited data available on their renal biocompatibility. Here we examine the biological responses of renal proximal tubule cells (LLC-PK1) exposed to fullerenol. Fullerenol was found to be cytotoxic in the millimolar range, with viability assessed by the sulforhodamine B and trypan blue assays. Fullerenol-induced cell death was associated with cytoskeleton disruption and autophagic vacuole accumulation. Interaction with the autophagy pathway was evaluated in vitro by Lysotracker Red dye uptake, LC3-II marker expression and TEM. Fullerenol treatment also resulted in coincident loss of cellular mitochondrial membrane potential and ATP depletion, as measured by the Mitotracker Red dye and the luciferin-luciferase assays, respectively. Fullerenol-induced ATP depletion and loss of mitochondrial potential were partially ameliorated by co-treatment with the autophagy inhibitor, 3-methyladenine. In vitro fullerenol treatment did not result in appreciable oxidative stress, as measured by lipid peroxide and glutathione content. Based on these data, it is hypothesized that cytoskeleton disruption may be an initiating event in fullerenol cytotoxicity, leading to subsequent autophagy dysfunction and loss of mitochondrial capacity. As nanoparticle-induced cytoskeleton disruption, autophagic vacuole accumulation and mitochondrial dysfunction are commonly reported in the literature, the proposed mechanism may be relevant for a variety of nanomaterials.

  15. Ceramides And Stress Signalling Intersect With Autophagic Defects In Neurodegenerative Drosophila blue cheese (bchs) Mutants.

    Science.gov (United States)

    Hebbar, Sarita; Sahoo, Ishtapran; Matysik, Artur; Argudo Garcia, Irene; Osborne, Kathleen Amy; Papan, Cyrus; Torta, Federico; Narayanaswamy, Pradeep; Fun, Xiu Hui; Wenk, Markus R; Shevchenko, Andrej; Schwudke, Dominik; Kraut, Rachel

    2015-12-07

    Sphingolipid metabolites are involved in the regulation of autophagy, a degradative recycling process that is required to prevent neuronal degeneration. Drosophila blue cheese mutants neurodegenerate due to perturbations in autophagic flux, and consequent accumulation of ubiquitinated aggregates. Here, we demonstrate that blue cheese mutant brains exhibit an elevation in total ceramide levels; surprisingly, however, degeneration is ameliorated when the pool of available ceramides is further increased, and exacerbated when ceramide levels are decreased by altering sphingolipid catabolism or blocking de novo synthesis. Exogenous ceramide is seen to accumulate in autophagosomes, which are fewer in number and show less efficient clearance in blue cheese mutant neurons. Sphingolipid metabolism is also shifted away from salvage toward de novo pathways, while pro-growth Akt and MAP pathways are down-regulated, and ER stress is increased. All these defects are reversed under genetic rescue conditions that increase ceramide generation from salvage pathways. This constellation of effects suggests a possible mechanism whereby the observed deficit in a potentially ceramide-releasing autophagic pathway impedes survival signaling and exacerbates neuronal death.

  16. Precise temporal regulation of roughest is required for correct salivary gland autophagic cell death in Drosophila.

    Science.gov (United States)

    Simon, Claudio R; Moda, Livia M R; Octacilio-Silva, Shirlei; Anhezini, Lucas; Machado-Gitai, Luciana C H; Ramos, Ricardo Guelerman P

    2009-07-01

    The Drosophila roughest (rst) locus encodes an immunoglobulin superfamily transmembrane glycoprotein implicated in a variety of embryonic and postembryonic developmental processes. Here we demonstrate a previously unnoticed role for this gene in the autophagic elimination of larval salivary glands during early pupal stages by showing that overexpression of the Rst protein ectodomain in early pupa leads to persistence of salivary glands up to at least 12 hours after head eversion, although with variable penetrance. The same phenotype is observed in individuals carrying the dominant regulatory allele rst(D), but not in loss of function alleles. Analysis of persistent glands at the ultrastructural level showed that programmed cell death starts at the right time but is arrested at an early stage of the process. Finally we describe the expression pattern and intracellular distribution of Rst in wild type and rst(D) mutants, showing that its downregulation in salivary glands at the beginning of pupal stage is an important factor in the correct implementation of the autophagic program of this tissue in space and time. 2009 Wiley-Liss, Inc.

  17. Current trends in laser fusion driver and beam combination laser system using stimulated Brillouin scattering phase conjugate mirrors for a fusion driver

    International Nuclear Information System (INIS)

    Kong, Hong Jin

    2008-01-01

    Laser fusion energy (LFE) is well known as one of the promising sources if clean energy for mankind. Laser fusion researches have been actively progressed, since Japan and the Soviet Union as well as USA developed ultrahigh power lasers at the beginning of 1970s. At present in USA, NIF (National Ignition Facility), which is the largest laser fusion facility in the world, is under construction and will be completed in 2008. Japan as a leader of the laser fusion research has developed a high energy and high power laser system, Gekko XII, and is under contemplation of FIREX projects for the fast ignition. China also has SG I, II lasers for performing the fusion research, and SG III is under construction as a next step. France is also constructing LMJ (Laser countries, many other developed countries in Europe, such as Russia, Germany, UK, and so on, have their own high energy laser systems for the fusion research. In Korea, the high power laser development started with SinMyung laser in KAIST in 1994, and KLF (KAERI Laser Facility) of KAERI was recently completed in 2007. For the practical use of laser fusion energy, the laser driver should be operated with a high repetition rate around 10Hz. Yet, current high energy laser systems, Such as NIF, Gekko XII, and etc., can be operated with only several shots per day. Some researchers have developed their own techniques to reduce the thermal loads of the laser material, by using laser diodes as pump sources and ceramic laser materials with high thermal energy scaling up for the real fusion driver. For this reason, H. J. Kong et al. proposed the beam combination laser system using stimulated Brillouin scattering phase conjugate mirrors (SBS PCMs) for a fusion driver. Proposed beam combination has many advantages for energy scaling up; it is composed by simple optical systems with small amount of components, there is no interaction between neighbored sub beams, the SBS PCMs can be used for a high energy beam reflection with

  18. Treatment with belimumab in systemic lupus erythematosus does not impair antibody response to 13-valent pneumococcal conjugate vaccine

    DEFF Research Database (Denmark)

    Nagel, J.; Saxne, T.; Geborek, P.

    2017-01-01

    in addition to standard of care therapy or with only hydroxychloroquine did not differ compared to controls, whereas the other treatment groups had significantly lower fold increase of post-vaccination antibody levels. Higher age was associated with lower post-vaccination antibody levels among systemic lupus...

  19. Multivalent system for therapy of non-Hod king lymphomas based on Anti-CD20 conjugated to gold nanoparticles

    International Nuclear Information System (INIS)

    Miranda O, R. M.

    2014-01-01

    In recent publications has been reported that gold nanoparticles have an effect in reducing the expression of the oncogene Bcl -2 and have a high biocompatibility , this is the importance for using gold nanoparticles for this work. The antibody CD20 is an antibody that specifically binds to that over expressed CD20 antigen on the cell membrane of B lymphoma cell non- Hodgkin (cell line Raji) behold the importance of combining this bio molecule to gold nanoparticles since they have a high specificity with CD20 positive cells , also to carry out the antigen- antibody immunological reactions triggered mediating cell lysis, possibly by cytotoxicity and apoptosis. Therefore, this system must have characteristics of both components to eliminate B cell non- Hodgkin lymphoma.In this work it was studied a multivalent system composed of gold nanoparticles and anti-CD20 antibody, the term multi valency refers to the number of biomolecules attached to the surface of the gold nanoparticle. The synthesis and characterization of the gold nanoparticles and the multivalent system was performed and the effect of the multivalent system on the expression of oncogene Bcl-2 (group of proteins associated with the apoptotic pathway) was evaluated. Characterization of raw materials and the multivalent system was performed using spectroscopic and microscopic techniques, this to verify structural changes in raw materials and thus confirm the formation of CD20 binding to the surface of the nanoparticle gold by the bond between gold and sulfur in the cysteines of CD20. Taking advantage that the metal nanoparticles have the optical property of surface plasmon resonance, the absorption of gold nanoparticles was measured on the UV-Vis as it is affected by the surface molecules bind to it, showing a bathochromic displacement effected. The hydrodynamic diameter of the gold nanoparticles was measured to verify that the antibody is bound to the surface; this evidence was complemented by micrographs

  20. Conjugate Gradient Algorithms For Manipulator Simulation

    Science.gov (United States)

    Fijany, Amir; Scheid, Robert E.

    1991-01-01

    Report discusses applicability of conjugate-gradient algorithms to computation of forward dynamics of robotic manipulators. Rapid computation of forward dynamics essential to teleoperation and other advanced robotic applications. Part of continuing effort to find algorithms meeting requirements for increased computational efficiency and speed. Method used for iterative solution of systems of linear equations.

  1. A NIM (Nuclear Instrumentation Module) system conjugated with optional input for pHEMT amplifier for beta and gamma spectroscopy

    International Nuclear Information System (INIS)

    Konrad, Barbara; Lüdke, Everton

    2014-01-01

    This work presents a high speed NIM module (Nuclear Instrumentation Module) to detect radiation, gamma and muons, as part of a system for natural radiation monitoring and of extraterrestrial origin. The subsystem developed consists of a preamplifier and an integrated SCA (Single Channel Analyzer), including power supplies of ± 12 and ± 24V with derivations of +3.6 and ± 5V. The single channel analyzer board, consisting of discrete logic components, operating in window modes, normal and integral. The pulse shaping block is made up of two voltage comparators working at 120 MHz with a response time > 60 ns and a logic anticoincidence system. The preamplifier promotes a noise reduction and introduces the impedance matching between the output of anode / diode photomultiplier tubes (PMTs) and subsequent equipment, providing an input impedance of 1MΩ and output impedance of 40 to 140Ω. The shaper amplifier is non-inverting and has variable input capacitance of 1000 pF. The upper and lower thresholds of the SCA are adjustable from 0 to ± 10V, and the equipment is compatible with various types of detectors, like PMTs coupled to sodium iodide crystals. For use with liquid scintillators and photodiodes with crystals (CsI: Tl) is proposed to include a preamplifier circuit pHEMT (pseudomorphic High Electron Mobility Transistor) integrated. Yet, the system presents the possibility of applications for various purposes of gamma spectroscopy and automatic detection of events producing of beta particles

  2. Poly(acrylic acid) conjugated hollow mesoporous carbon as a dual-stimuli triggered drug delivery system for chemo-photothermal synergistic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xian; Liu, Chang; Wang, Shengyu; Jiao, Jian; Di, Donghua; Jiang, Tongying; Zhao, Qinfu, E-mail: zqf021110505@163.com; Wang, Siling, E-mail: silingwang@syphu.edu.cn

    2017-02-01

    In this work, we described the development of the redox and pH dual stimuli-responsive drug delivery system and combination of the chemotherapy and photothermal therapy for cancer treatment. The poly(acrylic acid) (PAA) was conjugated on the outlets of hollow mesoporous carbon (HMC) via disulfide bonds. PAA was used as a capping to block drug within the mesopores of HMC for its lots of favorable advantages, such as good biocompatibility, appropriate molecular weight to block the mesopores of HMC, extension of the blood circulation, and the improvement of the dispersity of the nano-carriers in physiological environment. The DOX loaded DOX/HMC-SS-PAA had a high drug loading amount up to 51.9%. The in vitro drug release results illustrated that DOX/HMC-SS-PAA showed redox and pH dual-responsive drug release, and the release rate could be further improved by the near infrared (NIR) irradiation. Cell viability experiment indicated that DOX/HMC-SS-PAA had a synergistic therapeutic effect by combination of chemotherapy and photothermal therapy. This work suggested that HMC-SS-PAA exhibited dual-responsive drug release property and could be used as a NIR-adsorbing drug delivery system for chemo-photothermal synergistic therapy. - Highlights: • Poly(acrylic acid) was grafted on hollow mesoporous carbon (HMC) via disulfide bonds. • The grafted PAA could increase the biocompatibility and stability of HMC. • The DOX-loaded DOX/HMC-SS-PAA had a high drug loading efficiency up to 51.9%. • DOX/HMC-SS-PAA showed redox/pH dual-responsive and NIR-triggered drug release. • DOX/HMC-SS-PAA showed a chemo/photothermal synergistic therapy effect.

  3. Poly(acrylic acid) conjugated hollow mesoporous carbon as a dual-stimuli triggered drug delivery system for chemo-photothermal synergistic therapy

    International Nuclear Information System (INIS)

    Li, Xian; Liu, Chang; Wang, Shengyu; Jiao, Jian; Di, Donghua; Jiang, Tongying; Zhao, Qinfu; Wang, Siling

    2017-01-01

    In this work, we described the development of the redox and pH dual stimuli-responsive drug delivery system and combination of the chemotherapy and photothermal therapy for cancer treatment. The poly(acrylic acid) (PAA) was conjugated on the outlets of hollow mesoporous carbon (HMC) via disulfide bonds. PAA was used as a capping to block drug within the mesopores of HMC for its lots of favorable advantages, such as good biocompatibility, appropriate molecular weight to block the mesopores of HMC, extension of the blood circulation, and the improvement of the dispersity of the nano-carriers in physiological environment. The DOX loaded DOX/HMC-SS-PAA had a high drug loading amount up to 51.9%. The in vitro drug release results illustrated that DOX/HMC-SS-PAA showed redox and pH dual-responsive drug release, and the release rate could be further improved by the near infrared (NIR) irradiation. Cell viability experiment indicated that DOX/HMC-SS-PAA had a synergistic therapeutic effect by combination of chemotherapy and photothermal therapy. This work suggested that HMC-SS-PAA exhibited dual-responsive drug release property and could be used as a NIR-adsorbing drug delivery system for chemo-photothermal synergistic therapy. - Highlights: • Poly(acrylic acid) was grafted on hollow mesoporous carbon (HMC) via disulfide bonds. • The grafted PAA could increase the biocompatibility and stability of HMC. • The DOX-loaded DOX/HMC-SS-PAA had a high drug loading efficiency up to 51.9%. • DOX/HMC-SS-PAA showed redox/pH dual-responsive and NIR-triggered drug release. • DOX/HMC-SS-PAA showed a chemo/photothermal synergistic therapy effect.

  4. Effects of systemic multiexon skipping with peptide-conjugated morpholinos in the heart of a dog model of Duchenne muscular dystrophy.

    Science.gov (United States)

    Echigoya, Yusuke; Nakamura, Akinori; Nagata, Tetsuya; Urasawa, Nobuyuki; Lim, Kenji Rowel Q; Trieu, Nhu; Panesar, Dharminder; Kuraoka, Mutsuki; Moulton, Hong M; Saito, Takashi; Aoki, Yoshitsugu; Iversen, Patrick; Sazani, Peter; Kole, Ryszard; Maruyama, Rika; Partridge, Terry; Takeda, Shin'ichi; Yokota, Toshifumi

    2017-04-18

    Duchenne muscular dystrophy (DMD) is a lethal genetic disorder caused by an absence of the dystrophin protein in bodywide muscles, including the heart. Cardiomyopathy is a leading cause of death in DMD. Exon skipping via synthetic phosphorodiamidate morpholino oligomers (PMOs) represents one of the most promising therapeutic options, yet PMOs have shown very little efficacy in cardiac muscle. To increase therapeutic potency in cardiac muscle, we tested a next-generation morpholino: arginine-rich, cell-penetrating peptide-conjugated PMOs (PPMOs) in the canine X-linked muscular dystrophy in Japan (CXMD J ) dog model of DMD. A PPMO cocktail designed to skip dystrophin exons 6 and 8 was injected intramuscularly, intracoronarily, or intravenously into CXMD J dogs. Intravenous injections with PPMOs restored dystrophin expression in the myocardium and cardiac Purkinje fibers, as well as skeletal muscles. Vacuole degeneration of cardiac Purkinje fibers, as seen in DMD patients, was ameliorated in PPMO-treated dogs. Although symptoms and functions in skeletal muscle were not ameliorated by i.v. treatment, electrocardiogram abnormalities (increased Q-amplitude and Q/R ratio) were improved in CXMD J dogs after intracoronary or i.v. administration. No obvious evidence of toxicity was found in blood tests throughout the monitoring period of one or four systemic treatments with the PPMO cocktail (12 mg/kg/injection). The present study reports the rescue of dystrophin expression and recovery of the conduction system in the heart of dystrophic dogs by PPMO-mediated multiexon skipping. We demonstrate that rescued dystrophin expression in the Purkinje fibers leads to the improvement/prevention of cardiac conduction abnormalities in the dystrophic heart.

  5. [Role of proton-motive force in the conjugative DNA transport in Staphylococci].

    Science.gov (United States)

    Gavriliuk, V G; Vinnikov, A I

    1997-01-01

    Sensitivity of the conjugative process in staphylococci to the action of uncouplers of oxidative phosphorylation and inhibitors of electron transport systems have been proved, that testifies to the energy-dependent character of conjugative transport of DNA. Proceeding of the conjugation process depends upon the generation of delta microH+ on the membrane of both the donor and recipient cells. contribution of protonmotive forces to providing for the transfer of plasmids during conjugation to staphylococci has been defined.

  6. Tetrandrine, an Activator of Autophagy, Induces Autophagic Cell Death via PKC-α Inhibition and mTOR-Dependent Mechanisms

    Directory of Open Access Journals (Sweden)

    Vincent Kam Wai Wong

    2017-06-01

    Full Text Available Emerging evidence suggests the therapeutic role of autophagic modulators in cancer therapy. This study aims to identify novel traditional Chinese medicinal herbs as potential anti-tumor agents through autophagic induction, which finally lead to autophagy mediated-cell death in apoptosis-resistant cancer cells. Using bioactivity-guided purification, we identified tetrandrine (Tet from herbal plant, Radix stephaniae tetrandrae, as an inducer of autophagy. Across a number of cancer cell lines, we found that breast cancer cells treated with tetrandrine show an increase autophagic flux and formation of autophagosomes. In addition, tetrandrine induces cell death in a panel of apoptosis-resistant cell lines that are deficient for caspase 3, caspase 7, caspase 3 and 7, or Bax-Bak respectively. We also showed that tetrandrine-induced cell death is independent of necrotic cell death. Mechanistically, tetrandrine induces autophagy that depends on mTOR inactivation. Furthermore, tetrandrine induces autophagy in a calcium/calmodulin-dependent protein kinase kinase-β (CaMKK-β, 5′ AMP-activated protein kinase (AMPK independent manner. Finally, by kinase profiling against 300 WT kinases and computational molecular docking analysis, we showed that tetrandrine is a novel PKC-α inhibitor, which lead to autophagic induction through PKC-α inactivation. This study provides detailed insights into the novel cytotoxic mechanism of an anti-tumor compound originated from the herbal plant, which may be useful in promoting autophagy mediated- cell death in cancer cell that is resistant to apoptosis.

  7. Deoxycholate, an Endogenous Cytotoxin/Genotoxin, Induces the Autophagic Stress-Survival Pathway: Implications for Colon Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Claire M. Payne

    2009-01-01

    Full Text Available We report that deoxycholate (DOC, a hydrophobic bile acid associated with a high-fat diet, activates the autophagic pathway in non-cancer colon epithelial cells (NCM-460, and that this activation contributes to cell survival. The DOC-induced increase in autophagy was documented by an increase in autophagic vacuoles (detected using transmission electron microscopy, increased levels of LC3-I and LC3-II (western blotting, an increase in acidic vesicles (fluorescence spectroscopy of monodansycadaverine and lysotracker red probes, and increased expression of the autophagic protein, beclin-1 (immunohistochemistry/western blotting. The DOC-induced increase in beclin-1 expression was ROS-dependent. Rapamycin (activator of autophagy pre-treatment of NCM-460 cells significantly (P<.05 decreased, and 3-MA (inhibitor of autophagy significantly (P<.05 increased the cell loss caused by DOC treatment, alone. Rapamycin pre-treatment of the apoptosis-resistant colon cancer cell line, HCT-116RC (developed in our laboratory, resulted in a significant decrease in DOC-induced cell death. Bafilomycin A1 and hydroxychloroquine (inhibitors of the autophagic process increased the DOC-induced percentage of apoptotic cells in HCT-116RC cells. It was concluded that the activation of autophagy by DOC has important implications for colon carcinogenesis and for the treatment of colon cancer in conjunction with commonly used chemotherapeutic agents.

  8. Deoxycholate, an Endogenous Cytotoxin/Geno toxin, Induces the Autophagic Stress-Survival Pathway: Implications for Colon Carcinogenesis

    International Nuclear Information System (INIS)

    Payne, C.M.; Skillicorn, C.C.; Holubec, H.; Bernstein, C.; Dvorak, K.; Bernstein, H.; Moyer, M.P.; Garewal, H.

    2009-01-01

    We report that deoxycholate (DOC), a hydrophobic bile acid associated with a high-fat diet, activates the autophagic pathway in non-cancer colon epithelial cells (NCM-460), and that this activation contributes to cell survival. The DOC-induced increase in autophagy was documented by an increase in autophagic vacuoles (detected using transmission electron microscopy, increased levels of LC3-I and LC3-II (western blotting), an increase in acidic vesicles (fluorescence spectroscopy of monodansylcadaverine and lyso tracker red probes), and increased expression of the autophagic protein, beclin-1 (immunohistochemistry/western blotting). The DOC-induced increase in beclin-1 expression was ROS-dependent. Rapa mycin (activator of autophagy) pre-treatment of NCM-460 cells significantly (P<.05) decreased, and 3-MA (inhibitor of autophagy) significantly (P<.05) increased the cell loss caused by DOC treatment, alone. Rapa mycin pre-treatment of the apoptosis-resistant colon cancer cell line, HCT-116RC (developed in our laboratory), resulted in a significant decrease in DOC-induced cell death. Bafilomycin A1 and hydroxychloroquine (inhibitors of the autophagic process) increased the DOC-induced percentage of apoptotic cells in HCT-116RC cells. It was concluded that the activation of autophagy by DOC has important implications for colon carcinogenesis and for the treatment of colon cancer in conjunction with commonly used chemotherapeutic agents.

  9. Serratia marcescens Is Able to Survive and Proliferate in Autophagic-Like Vacuoles inside Non-Phagocytic Cells

    Science.gov (United States)

    Colombo, María Isabel; García Véscovi, Eleonora

    2011-01-01

    Serratia marcescens is an opportunistic human pathogen that represents a growing problem for public health, particularly in hospitalized or immunocompromised patients. However, little is known about factors and mechanisms that contribute to S. marcescens pathogenesis within its host. In this work, we explore the invasion process of this opportunistic pathogen to epithelial cells. We demonstrate that once internalized, Serratia is able not only to persist but also to multiply inside a large membrane-bound compartment. This structure displays autophagic-like features, acquiring LC3 and Rab7, markers described to be recruited throughout the progression of antibacterial autophagy. The majority of the autophagic-like vacuoles in which Serratia resides and proliferates are non-acidic and have no degradative properties, indicating that the bacteria are capable to either delay or prevent fusion with lysosomal compartments, altering the expected progression of autophagosome maturation. In addition, our results demonstrate that Serratia triggers a non-canonical autophagic process before internalization. These findings reveal that S. marcescens is able to manipulate the autophagic traffic, generating a suitable niche for survival and proliferation inside the host cell. PMID:21901159

  10. System Development from Organic Solvents to Ionic Liquids for Synthesiz-ing Ascorbyl Esters with Conjugated Linoleic Acids

    DEFF Research Database (Denmark)

    Yang, Zhiyong; Schultz, Lise; Guo, Zheng

    2012-01-01

    . Results show that only Novozym® 435 turned out to be a useful enzymatic preparation for the production of ascorbyl-CLA ester. The optimum reaction conditions in the or-ganic solvent system were 4 h at 55°C and at a molar ratio of 5 (CLA/ascorbic acid). The esterification reaction was trans......-ferred to an ionic liquid system for the purpose of improving solubility of the polar substrate and avoiding the application of organic solvents. From screening experiments, it was evident that only methyltrioctylammonium triflouroacetate (tO-MA·TFA) could provide a proper reaction environment for production...... of ascorbyl-CLA ester when using Novozym® 435 as biocatalyst. It was possible to significantly increase the productivity (150 g/l) through the increase of ascorbic acid sol-ubility in ionic liquids by super saturation together with the increase of reaction temperature to 70°C, far beyond than that in organic...

  11. METHOD OF CONJUGATED CIRCULAR ARCS TRACING

    Directory of Open Access Journals (Sweden)

    N. Ageyev Vladimir

    2017-01-01

    Full Text Available The geometric properties of conjugated circular arcs connecting two points on the plane with set directions of tan- gent vectors are studied in the work. It is shown that pairs of conjugated circular arcs with the same conditions in frontier points create one-parameter set of smooth curves tightly filling all the plane. One of the basic properties of this set is the fact that all coupling points of circular arcs are on the circular curve going through the initially given points. The circle radius depends on the direction of tangent vectors. Any point of the circle curve, named auxiliary in this work, determines a pair of conjugated arcs with given boundary conditions. One more condition of the auxiliary circle curve is that it divides the plane into two parts. The arcs going from the initial point are out of the circle limited by this circle curve and the arcs coming to the final point are inside it. These properties are the basis for the method of conjugated circular arcs tracing pro- posed in this article. The algorithm is rather simple and allows to fulfill all the needed plottings using only the divider and ruler. Two concrete examples are considered. The first one is related to the problem of tracing of a pair of conjugated arcs with the minimal curve jump when going through the coupling point. The second one demonstrates the possibility of trac- ing of the smooth curve going through any three points on the plane under condition that in the initial and final points the directions of tangent vectors are given. The proposed methods of conjugated circular arcs tracing can be applied in solving of a wide variety of problems connected with the tracing of cam contours, for example pattern curves in textile industry or in computer-aided-design systems when programming of looms with numeric control.

  12. Can model Hamiltonians describe the electron–electron interaction in π-conjugated systems?: PAH and graphene

    International Nuclear Information System (INIS)

    Chiappe, G; Louis, E; San-Fabián, E; Vergés, J A

    2015-01-01

    Model Hamiltonians have been, and still are, a valuable tool for investigating the electronic structure of systems for which mean field theories work poorly. This review will concentrate on the application of Pariser–Parr–Pople (PPP) and Hubbard Hamiltonians to investigate some relevant properties of polycyclic aromatic hydrocarbons (PAH) and graphene. When presenting these two Hamiltonians we will resort to second quantisation which, although not the way chosen in its original proposal of the former, is much clearer. We will not attempt to be comprehensive, but rather our objective will be to try to provide the reader with information on what kinds of problems they will encounter and what tools they will need to solve them. One of the key issues concerning model Hamiltonians that will be treated in detail is the choice of model parameters. Although model Hamiltonians reduce the complexity of the original Hamiltonian, they cannot be solved in most cases exactly. So, we shall first consider the Hartree–Fock approximation, still the only tool for handling large systems, besides density functional theory (DFT) approaches. We proceed by discussing to what extent one may exactly solve model Hamiltonians and the Lanczos approach. We shall describe the configuration interaction (CI) method, a common technology in quantum chemistry but one rarely used to solve model Hamiltonians. In particular, we propose a variant of the Lanczos method, inspired by CI, that has the novelty of using as the seed of the Lanczos process a mean field (Hartree–Fock) determinant (the method will be named LCI). Two questions of interest related to model Hamiltonians will be discussed: (i) when including long-range interactions, how crucial is including in the Hamiltonian the electronic charge that compensates ion charges? (ii) Is it possible to reduce a Hamiltonian incorporating Coulomb interactions (PPP) to an ‘effective’ Hamiltonian including only on-site interactions (Hubbard)? The

  13. Genetic engineering in Actinoplanes sp. SE50/110 - development of an intergeneric conjugation system for the introduction of actinophage-based integrative vectors.

    Science.gov (United States)

    Gren, Tetiana; Ortseifen, Vera; Wibberg, Daniel; Schneiker-Bekel, Susanne; Bednarz, Hanna; Niehaus, Karsten; Zemke, Till; Persicke, Marcus; Pühler, Alfred; Kalinowski, Jörn

    2016-08-20

    The α-glucosidase inhibitor acarbose is used for treatment of diabetes mellitus type II, and is manufactured industrially with overproducing derivatives of Actinoplanes sp. SE50/110, reportedly obtained by conventional mutagenesis. Despite of high industrial significance, only limited information exists regarding acarbose metabolism, function and regulation of these processes, due to the absence of proper genetic engineering methods and tools developed for this strain. Here, a basic toolkit for genetic engineering of Actinoplanes sp. SE50/110 was developed, comprising a standardized protocol for a DNA transfer through Escherichia coli-Actinoplanes intergeneric conjugation and applied for the transfer of ϕC31, ϕBT1 and VWB actinophage-based integrative vectors. Integration sites, occurring once per genome for all vectors, were sequenced and characterized for the first time in Actinoplanes sp. SE50/110. Notably, in case of ϕC31 based vector pSET152, the integration site is highly conserved, while for ϕBT1 and the VWB based vectors pRT801 and pSOK804, respectively, no sequence similarities to those in other bacteria were detected. The studied plasmids were proven to be stable and neutral with respect to strain morphology and acarbose production, enabling future use for genetic manipulations of Actinoplanes sp. SE50/110. To further broaden the spectrum of available tools, a GUS reporter system, based on the pSET152 derived vector, was also established in Actinoplanes sp. SE50/110. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A novel strategy inducing autophagic cell death in Burkitt's lymphoma cells with anti-CD19-targeted liposomal rapamycin

    International Nuclear Information System (INIS)

    Ono, K; Sato, T; Iyama, S; Tatekoshi, A; Hashimoto, A; Kamihara, Y; Horiguchi, H; Kikuchi, S; Kawano, Y; Takada, K; Hayashi, T; Miyanishi, K; Sato, Y; Takimoto, R; Kobune, M; Kato, J

    2014-01-01

    Relapsed or refractory Burkitt's lymphoma often has a poor prognosis in spite of intensive chemotherapy that induces apoptotic and/or necrotic death of lymphoma cells. Rapamycin (Rap) brings about autophagy, and could be another treatment. Further, anti-CD19-targeted liposomal delivery may enable Rap to kill lymphoma cells specifically. Rap was encapsulated by anionic liposome and conjugated with anti-CD19 antibody (CD19-GL-Rap) or anti-CD2 antibody (CD2-GL-Rap) as a control. A fluorescent probe Cy5.5 was also liposomized in the same way (CD19 or CD2-GL-Cy5.5) to examine the efficacy of anti-CD19-targeted liposomal delivery into CD19-positive Burkitt's lymphoma cell line, SKW6.4. CD19-GL-Cy5.5 was more effectively uptaken into SKW6.4 cells than CD2-GL-Cy5.5 in vitro. When the cells were inoculated subcutaneously into nonobese diabetic/severe combined immunodeficiency mice, intravenously administered CD19-GL-Cy5.5 made the subcutaneous tumor fluorescent, while CD2-GL-Cy5.5 did not. Further, CD19-GL-Rap had a greater cytocidal effect on not only SKW6.4 cells but also Burkitt's lymphoma cells derived from patients than CD2-GL-Rap in vitro. The specific toxicity of CD19-GL-Rap was cancelled by neutralizing anti-CD19 antibody. The survival period of mice treated with intravenous CD19-GL-Rap was significantly longer than that of mice treated with CD2-GL-Rap after intraperitoneal inoculation of SKW6.4 cells. Anti-CD19-targeted liposomal Rap could be a promising lymphoma cell-specific treatment inducing autophagic cell death

  15. Acadesine kills chronic myelogenous leukemia (CML cells through PKC-dependent induction of autophagic cell death.

    Directory of Open Access Journals (Sweden)

    Guillaume Robert

    Full Text Available CML is an hematopoietic stem cell disease characterized by the t(9;22 (q34;q11 translocation encoding the oncoprotein p210BCR-ABL. The effect of acadesine (AICAR, 5-Aminoimidazole-4-carboxamide-1-beta-D-ribofuranoside a compound with known antileukemic effect on B cell chronic lymphoblastic leukemia (B-CLL was investigated in different CML cell lines. Acadesine triggered loss of cell metabolism in K562, LAMA-84 and JURL-MK1 and was also effective in killing imatinib-resistant K562 cells and Ba/F3 cells carrying the T315I-BCR-ABL mutation. The anti-leukemic effect of acadesine did not involve apoptosis but required rather induction of autophagic cell death. AMPK knock-down by Sh-RNA failed to prevent the effect of acadesine, indicating an AMPK-independent mechanism. The effect of acadesine was abrogated by GF109203X and Ro-32-0432, both inhibitor of classical and new PKCs and accordingly, acadesine triggered relocation and activation of several PKC isoforms in K562 cells. In addition, this compound exhibited a potent anti-leukemic effect in clonogenic assays of CML cells in methyl cellulose and in a xenograft model of K562 cells in nude mice. In conclusion, our work identifies an original and unexpected mechanism by which acadesine triggers autophagic cell death through PKC activation. Therefore, in addition to its promising effects in B-CLL, acadesine might also be beneficial for Imatinib-resistant CML patients.

  16. Adipose tissue conditioned media support macrophage lipid-droplet biogenesis by interfering with autophagic flux.

    Science.gov (United States)

    Bechor, Sapir; Nachmias, Dikla; Elia, Natalie; Haim, Yulia; Vatarescu, Maayan; Leikin-Frenkel, Alicia; Gericke, Martin; Tarnovscki, Tanya; Las, Guy; Rudich, Assaf

    2017-09-01

    Obesity promotes the biogenesis of adipose tissue (AT) foam cells (FC), which contribute to AT insulin resistance. Autophagy, an evolutionarily-conserved house-keeping process, was implicated in cellular lipid handling by either feeding and/or degrading lipid-droplets (LDs). We hypothesized that beyond phagocytosis of dead adipocytes, AT-FC biogenesis is supported by the AT microenvironment by regulating autophagy. Non-polarized ("M0") RAW264.7 macrophages exposed to AT conditioned media (AT-CM) exhibited a markedly enhanced LDs biogenesis rate compared to control cells (8.3 Vs 0.3 LDs/cells/h, p<0.005). Autophagic flux was decreased by AT-CM, and fluorescently following autophagosomes over time revealed ~20% decline in new autophagic vesicles' formation rate, and 60-70% decrease in autophagosomal growth rate, without marked alternations in the acidic lysosomal compartment. Suppressing autophagy by either targeting autophagosome formation (pharmacologically, with 3-methyladenine or genetically, with Atg12±Atg7-siRNA), decreased the rate of LD formation induced by oleic acid. Conversely, interfering with late autophago-lysosomal function, either pharmacologically with bafilomycin-A1, chloroquine or leupeptin, enhanced LD formation in macrophages without affecting LD degradation rate. Similarly enhanced LD biogenesis rate was induced by siRNA targeting Lamp-1 or the V-ATPase. Collectively, we propose that secreted products from AT interrupt late autophagosome maturation in macrophages, supporting enhanced LDs biogenesis and AT-FC formation, thereby contributing to AT dysfunction in obesity. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  17. Autophagic flux without a block differentiates varicella-zoster virus infection from herpes simplex virus infection.

    Science.gov (United States)

    Buckingham, Erin M; Carpenter, John E; Jackson, Wallen; Zerboni, Leigh; Arvin, Ann M; Grose, Charles

    2015-01-06

    Autophagy is a process by which misfolded and damaged proteins are sequestered into autophagosomes, before degradation in and recycling from lysosomes. We have extensively studied the role of autophagy in varicella-zoster virus (VZV) infection, and have observed that vesicular cells are filled with >100 autophagosomes that are easily detectable after immunolabeling for the LC3 protein. To confirm our hypothesis that increased autophagosome formation was not secondary to a block, we examined all conditions of VZV infection as well as carrying out two assessments of autophagic flux. We first investigated autophagy in human skin xenografts in the severe combined immunodeficiency (SCID) mouse model of VZV pathogenesis, and observed that autophagosomes were abundant in infected human skin tissues. We next investigated autophagy following infection with sonically prepared cell-free virus in cultured cells. Under these conditions, autophagy was detected in a majority of infected cells, but was much less than that seen after an infected-cell inoculum. In other words, inoculation with lower-titered cell-free virus did not reflect the level of stress to the VZV-infected cell that was seen after inoculation of human skin in the SCID mouse model or monolayers with higher-titered infected cells. Finally, we investigated VZV-induced autophagic flux by two different methods (radiolabeling proteins and a dual-colored LC3 plasmid); both showed no evidence of a block in autophagy. Overall, therefore, autophagy within a VZV-infected cell was remarkably different from autophagy within an HSV-infected cell, whose genome contains two modifiers of autophagy, ICP34.5 and US11, not present in VZV.

  18. Technology of DTPA and immunoglobulins conjugation and their attachment to 90Y and 177Lu radionuclides

    International Nuclear Information System (INIS)

    Rekova, M.; Jedinakova-Krizova, V.

    2010-01-01

    The aim of the study of labeling of ligand-antibody conjugates was to find optimal conditions of preparing of these conjugates and appropriate radioactivity of selected nuclide for applications in nuclear medicine. Conjugation of the γ-immunoglobulin G (human or bovine IgG, polyclonal antibodies) and bifunctional chelating agent, diethylenetriaminepentaacetic acid dianhydride (cDTPAA), was carried out. Various values of the cDTPAA/antibody ratio, the weight concentration of polyclonal or monoclonal antibodies (MEM-97) and buffers were used. Further, the labeling conditions of the DTPA-IgG conjugate by radionuclides 90 Y and 177 Lu were optimized, and the labeling yield and the conjugation ratio of prepared radionuclide-DTPA-IgG conjugates was determined. Optimal incubation time of the immunoglobulin conjugation was obtained at 30 min from mixing of individual components. The labeling yield of radionuclide-DTPA-antibody conjugate higher than 95% was achieved. Higher values of conjugation ratio of radionuclide-DTPA-antibody conjugate were achieved in 0.1 mol L -1 carbonate buffer, pH 8.5, and the 0.1 mol L -1 carbonate buffer is suitable for studied conjugation systems. This study showed that the labeling yield as well as the conjugation ratio of tested systems depend on the amount of antibody substance, bifunctional chelating agent/antibody molar ratio and pH value of the buffer used. (author)

  19. Conjugate Problems in Convective Heat Transfer: Review

    Directory of Open Access Journals (Sweden)

    Abram Dorfman

    2009-01-01

    Full Text Available A review of conjugate convective heat transfer problems solved during the early and current time of development of this modern approach is presented. The discussion is based on analytical solutions of selected typical relatively simple conjugate problems including steady-state and transient processes, thermal material treatment, and heat and mass transfer in drying. This brief survey is accompanied by the list of almost two hundred publications considering application of different more and less complex analytical and numerical conjugate models for simulating technology processes and industrial devices from aerospace systems to food production. The references are combined in the groups of works studying similar problems so that each of the groups corresponds to one of selected analytical solutions considered in detail. Such structure of review gives the reader the understanding of early and current situation in conjugate convective heat transfer modeling and makes possible to use the information presented as an introduction to this area on the one hand, and to find more complicated publications of interest on the other hand.

  20. Organometallic B12-DNA conjugate

    DEFF Research Database (Denmark)

    Hunger, Miriam; Mutti, Elena; Rieder, Alexander

    2014-01-01

    Design, synthesis, and structural characterization of a B12-octadecanucleotide are presented herein, a new organometallic B12-DNA conjugate. In such covalent conjugates, the natural B12 moiety may be a versatile vector for controlled in vivo delivery of oligonucleotides to cellular targets in hum...

  1. Perfect lensing with phase-conjugating surfaces: toward practical realization

    International Nuclear Information System (INIS)

    Maslovski, Stanislav; Tretyakov, Sergei

    2012-01-01

    It is theoretically known that a pair of phase-conjugating surfaces can function as a perfect lens, focusing propagating waves and enhancing evanescent waves. However, the known experimental approaches based on thin sheets of nonlinear materials cannot fully realize the required phase conjugation boundary condition. In this paper, we show that the ideal phase-conjugating surface is, in principle, physically realizable and investigate the necessary properties of nonlinear and nonreciprocal particles which can be used to build a perfect lens system. The physical principle of the lens operation is discussed in detail and directions of possible experimental realizations are outlined. (paper)

  2. Conjugation in Escherichia coli

    Science.gov (United States)

    Boyer, Herbert

    1966-01-01

    Boyer, Herbert (Yale University, New Haven, Conn.). Conjugation in Escherichia coli. J. Bacteriol. 91:1767–1772. 1966.—The sex factor of Escherichia coli K-12 was introduced into an E. coli B/r strain by circumventing the host-controlled modification and restriction incompatibilities known to exist between these closely related strains. The sexual properties of the constructed F+ B strain and its Hfr derivatives were examined. These studies showed that the E. coli strain B/r F+ and Hfr derivatives are similar to the E. coli strain K-12 F+ and Hfr derivatives. However, the site of sex factor integration was found to be dependent on the host genome. PMID:5327905

  3. Nanostructured conjugated polymers in chemical sensors: synthesis, properties and applications.

    Science.gov (United States)

    Correa, D S; Medeiros, E S; Oliveira, J E; Paterno, L G; Mattoso, Luiz C

    2014-09-01

    Conjugated polymers are organic materials endowed with a π-electron conjugation along the polymer backbone that present appealing electrical and optical properties for technological applications. By using conjugated polymeric materials in the nanoscale, such properties can be further enhanced. In addition, the use of nanostructured materials makes possible miniaturize devices at the micro/nano scale. The applications of conjugated nanostructured polymers include sensors, actuators, flexible displays, discrete electronic devices, and smart fabric, to name a few. In particular, the use of conjugated polymers in chemical and biological sensors is made feasible owning to their sensitivity to the physicochemical conditions of its surrounding environment, such as chemical composition, pH, dielectric constant, humidity or even temperature. Subtle changes in these conditions bring about variations on the electrical (resistivity and capacitance), optical (absorptivity, luminescence, etc.), and mechanical properties of the conjugated polymer, which can be precisely measured by different experimental methods and ultimately associated with a specific analyte and its concentration. The present review article highlights the main features of conjugated polymers that make them suitable for chemical sensors. An especial emphasis is given to nanostructured sensors systems, which present high sensitivity and selectivity, and find application in beverage and food quality control, pharmaceutical industries, medical diagnosis, environmental monitoring, and homeland security, and other applications as discussed throughout this review.

  4. Autophagic signaling and proteolytic enzyme activity in cardiac and skeletal muscle of spontaneously hypertensive rats following chronic aerobic exercise.

    Directory of Open Access Journals (Sweden)

    Elliott M McMillan

    Full Text Available Hypertension is a cardiovascular disease associated with deleterious effects in skeletal and cardiac muscle. Autophagy is a degradative process essential to muscle health. Acute exercise can alter autophagic signaling. Therefore, we aimed to characterize the effects of chronic endurance exercise on autophagy in skeletal and cardiac muscle of normotensive and hypertensive rats. Male Wistar Kyoto (WKY and spontaneously hypertensive rats (SHR were assigned to a sedentary condition or 6 weeks of treadmill running. White gastrocnemius (WG of hypertensive rats had higher (p<0.05 caspase-3 and proteasome activity, as well as elevated calpain activity. In addition, skeletal muscle of hypertensive animals had elevated (p<0.05 ATG7 and LC3I protein, LAMP2 mRNA, and cathepsin activity, indicative of enhanced autophagic signaling. Interestingly, chronic exercise training increased (p<0.05 Beclin-1, LC3, and p62 mRNA as well as proteasome activity, but reduced (p<0.05 Beclin-1 and ATG7 protein, as well as decreased (p<0.05 caspase-3, calpain, and cathepsin activity. Left ventricle (LV of hypertensive rats had reduced (p<0.05 AMPKα and LC3II protein, as well as elevated (p<0.05 p-AKT, p-p70S6K, LC3I and p62 protein, which collectively suggest reduced autophagic signaling. Exercise training had little effect on autophagy-related signaling factors in LV; however, exercise training increased (p<0.05 proteasome activity but reduced (p<0.05 caspase-3 and calpain activity. Our results suggest that autophagic signaling is altered in skeletal and cardiac muscle of hypertensive animals. Regular aerobic exercise can effectively alter the proteolytic environment in both cardiac and skeletal muscle, as well as influence several autophagy-related factors in skeletal muscle of normotensive and hypertensive rats.

  5. Endurance exercise training induces fat depot-specific differences in basal autophagic activity

    International Nuclear Information System (INIS)

    Tanaka, Goki; Kato, Hisashi; Izawa, Tetsuya

    2015-01-01

    The purpose of this study was to uncover the effect of exercise training on the expression of autophagy marker proteins in epididymal white adipose tissue (eWAT), inguinal WAT (iWAT), and the stromal vascular fraction (SVF) collected from eWAT. Male Wistar rats aged 4–5 weeks were randomly divided into two groups, sedentary control (n = 7) and exercise-trained (n = 7). Rats in the exercise-trained group were exercised on a treadmill set at a 5° incline 5 days/week for 9 weeks. We determined that the expression levels of an autophagosome-associating form of microtubule-associated protein 1 light chain 3 (LC3)-II and of p62 were significantly higher in eWAT from exercise-trained than from control rats, while those of adipose-specific deletion of autophagy-related protein (ATG7) and lysosomal-associated membrane protein type 2A (LAMP2a) showed no difference between groups. However, in iWAT, the expression levels of LC3-II and ATG7 were significantly higher in exercise-trained than in control rats. The expression of p62 was highly correlated with that of peroxisome proliferator-activated receptor γ (PPARγ), a master regulator of adipogenesis and lipid metabolism, in both WAT types (eWAT, r = 0.856, P < 0.05; iWAT, r = 0.762, P < 0.05), whereas LC3-II and PPARγ levels were highly correlated in eWAT (r = 0.765, P < 0.05) but not in iWAT (r = −0.306, ns). In SVF, the expression levels of LC3II, ATG7, and LAMP2a were significantly higher in exercise-trained than in control rats. These results suggest that exercise training suppresses basal autophagy activity in eWAT, but that this activity is enhanced in iWAT and SVF collected from eWAT. Thus, the adaptation of basal autophagic activity following exercise training exhibits fat depot-specific differences. - Highlights: • Autophagy has been associated with obesity and associated diseases. • We examined exercise-associated rat white adipose tissue (WAT) autophagy markers. • Exercise increased

  6. Endurance exercise training induces fat depot-specific differences in basal autophagic activity

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Goki; Kato, Hisashi; Izawa, Tetsuya, E-mail: tizawa@mail.doshisha.ac.jp

    2015-10-23

    The purpose of this study was to uncover the effect of exercise training on the expression of autophagy marker proteins in epididymal white adipose tissue (eWAT), inguinal WAT (iWAT), and the stromal vascular fraction (SVF) collected from eWAT. Male Wistar rats aged 4–5 weeks were randomly divided into two groups, sedentary control (n = 7) and exercise-trained (n = 7). Rats in the exercise-trained group were exercised on a treadmill set at a 5° incline 5 days/week for 9 weeks. We determined that the expression levels of an autophagosome-associating form of microtubule-associated protein 1 light chain 3 (LC3)-II and of p62 were significantly higher in eWAT from exercise-trained than from control rats, while those of adipose-specific deletion of autophagy-related protein (ATG7) and lysosomal-associated membrane protein type 2A (LAMP2a) showed no difference between groups. However, in iWAT, the expression levels of LC3-II and ATG7 were significantly higher in exercise-trained than in control rats. The expression of p62 was highly correlated with that of peroxisome proliferator-activated receptor γ (PPARγ), a master regulator of adipogenesis and lipid metabolism, in both WAT types (eWAT, r = 0.856, P < 0.05; iWAT, r = 0.762, P < 0.05), whereas LC3-II and PPARγ levels were highly correlated in eWAT (r = 0.765, P < 0.05) but not in iWAT (r = −0.306, ns). In SVF, the expression levels of LC3II, ATG7, and LAMP2a were significantly higher in exercise-trained than in control rats. These results suggest that exercise training suppresses basal autophagy activity in eWAT, but that this activity is enhanced in iWAT and SVF collected from eWAT. Thus, the adaptation of basal autophagic activity following exercise training exhibits fat depot-specific differences. - Highlights: • Autophagy has been associated with obesity and associated diseases. • We examined exercise-associated rat white adipose tissue (WAT) autophagy markers. • Exercise increased

  7. Lapatinib induces autophagic cell death and differentiation in acute myeloblastic leukemia

    Directory of Open Access Journals (Sweden)

    Chen YJ

    2016-07-01

    Full Text Available Yu-Jen Chen,1–4 Li-Wen Fang,5 Wen-Chi Su,6,7 Wen-Yi Hsu,1 Kai-Chien Yang,1 Huey-Lan Huang8 1Department of Medical Research, 2Department of Radiation Oncology, Mackay Memorial Hospital, 3Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, 4Institute of Pharmacology, Taipei Medical University, Taipei, 5Department of Nutrition, I-Shou University, Kaohsiung, 6Research Center for Emerging Viruses, China Medical University Hospital, 7Graduate Institute of Clinical Medical Science, China Medical University, Taichung, 8Department of Bioscience Technology, College of Health Science, Chang Jung Christian University, Tainan, Taiwan, Republic of China Abstract: Lapatinib is an oral-form dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR or ErbB/Her superfamily members with anticancer activity. In this study, we examined the effects and mechanism of action of lapatinib on several human leukemia cells lines, including acute myeloid leukemia (AML, chronic myeloid leukemia (CML, and acute lymphoblastic leukemia (ALL cells. We found that lapatinib inhibited the growth of human AML U937, HL-60, NB4, CML KU812, MEG-01, and ALL Jurkat T cells. Among these leukemia cell lines, lapatinib induced apoptosis in HL-60, NB4, and Jurkat cells, but induced nonapoptotic cell death in U937, K562, and MEG-01 cells. Moreover, lapatinib treatment caused autophagic cell death as shown by positive acridine orange staining, the massive formation of vacuoles as seen by electronic microscopy, and the upregulation of LC3-II, ATG5, and ATG7 in AML U937 cells. Furthermore, autophagy inhibitor 3-methyladenine and knockdown of ATG5, ATG7, and Beclin-1 using short hairpin RNA (shRNA partially rescued lapatinib-induced cell death. In addition, the induction of phagocytosis and ROS production as well as the upregulation of surface markers CD14 and CD68 was detected in lapatinib-treated U937 cells, suggesting the induction of

  8. Charge conjugation invariance of the spectator equations

    International Nuclear Information System (INIS)

    Gross, F.

    1999-01-01

    In response to recent criticism, the authors show how to define the spectator equations for negative energies so that charge conjugation invariance is preserved. The result, which emerges naturally from the application of spectator principles to systems of particles with negative energies, is to replace all factors of the external energies W iota by √ W 2 iota , insuring that the amplitudes are independent of the sign of the energies W iota

  9. Conjugated Linoleic Acid: good or bad nutrient

    Directory of Open Access Journals (Sweden)

    Gonçalves Daniela C

    2010-10-01

    Full Text Available Abstract Conjugated linoleic acid (CLA is a class of 28 positional and geometric isomers of linoleic acid octadecadienoic.Currently, it has been described many benefits related to the supplementation of CLA in animals and humans, as in the treatment of cancer, oxidative stress, in atherosclerosis, in bone formation and composition in obesity, in diabetes and the immune system. However, our results show that, CLA appears to be not a good supplement in patients with cachexia.

  10. M-step preconditioned conjugate gradient methods

    Science.gov (United States)

    Adams, L.

    1983-01-01

    Preconditioned conjugate gradient methods for solving sparse symmetric and positive finite systems of linear equations are described. Necessary and sufficient conditions are given for when these preconditioners can be used and an analysis of their effectiveness is given. Efficient computer implementations of these methods are discussed and results on the CYBER 203 and the Finite Element Machine under construction at NASA Langley Research Center are included.

  11. AMPK activation protects cells from oxidative stress-induced senescence via autophagic flux restoration and intracellular NAD(+) elevation.

    Science.gov (United States)

    Han, Xiaojuan; Tai, Haoran; Wang, Xiaobo; Wang, Zhe; Zhou, Jiao; Wei, Xiawei; Ding, Yi; Gong, Hui; Mo, Chunfen; Zhang, Jie; Qin, Jianqiong; Ma, Yuanji; Huang, Ning; Xiang, Rong; Xiao, Hengyi

    2016-06-01

    AMPK activation is beneficial for cellular homeostasis and senescence prevention. However, the molecular events involved in AMPK activation are not well defined. In this study, we addressed the mechanism underlying the protective effect of AMPK on oxidative stress-induced senescence. The results showed that AMPK was inactivated in senescent cells. However, pharmacological activation of AMPK by metformin and berberine significantly prevented the development of senescence and, accordingly, inhibition of AMPK by Compound C was accelerated. Importantly, AMPK activation prevented hydrogen peroxide-induced impairment of the autophagic flux in senescent cells, evidenced by the decreased p62 degradation, GFP-RFP-LC3 cancellation, and activity of lysosomal hydrolases. We also found that AMPK activation restored the NAD(+) levels in the senescent cells via a mechanism involving mostly the salvage pathway for NAD(+) synthesis. In addition, the mechanistic relationship of autophagic flux and NAD(+) synthesis and the involvement of mTOR and Sirt1 activities were assessed. In summary, our results suggest that AMPK prevents oxidative stress-induced senescence by improving autophagic flux and NAD(+) homeostasis. This study provides a new insight for exploring the mechanisms of aging, autophagy and NAD(+) homeostasis, and it is also valuable in the development of innovative strategies to combat aging. © 2016 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  12. T315 Decreases Acute Myeloid Leukemia Cell Viability through a Combination of Apoptosis Induction and Autophagic Cell Death

    Directory of Open Access Journals (Sweden)

    Chang-Fang Chiu

    2016-08-01

    Full Text Available T315, an integrin-linked kinase (ILK inhibitor, has been shown to suppress the proliferation of breast cancer, stomach cancer and chronic lymphocytic leukemia cells. Here we demonstrate that T315 decreases cell viability of acute myeloid leukemia (AML cell lines (HL-60 and THP-1 and primary leukemia cells from AML patients in a dose-responsive manner. Normal human bone marrow cells are less sensitive than leukemia cells to T315. T315 down regulates protein kinase B (Akt and p-Akt and induces caspase activation, poly-ADP-ribose polymerase (PARP cleavage, apoptosis and autophagy through an ILK-independent manner. Interestingly, pretreatment with autophagy inhibitors rescues cells from apoptosis and concomitant PARP cleavage, which implicates a key role of autophagic cell death in T315-mediated cytotoxicity. T315 also demonstrates efficacy in vivo, suppressing the growth of THP-1 xenograft tumors in athymic nude mice when administered intraperitoneally. This study shows that autophagic cell death and apoptosis cooperatively contribute to the anticancer activity of T315 in AML cells. In conclusion, the complementary roles of apoptotic and autophagic cell death should be considered in the future assessment of the translational value of T315 in AML therapy.

  13. Occurrence of Conjugated Linolenic Acids in Purified Soybean Oil

    OpenAIRE

    Kinami, Tomohisa; Horii, Naoto; Narayan, Bhaskar; Arato, Shingo; Hosokawa, Masashi; Miyashita, Kazuo; Negishi, Hironori; Ikuina, Junichi; Noda, Ryuji; Shirasawa, Seiichi

    2007-01-01

    A high-performance liquid chromatographic (HPLC) method is described for the determination of conjugated linoleic acids (CLA) and conjugated linolenic acids (CLN). Methyl esters prepared from purified lipid fractions of soybean oil were analyzed using an HPLC system equipped with photodiode-array detector to detect peaks having maximum absorption around 233 and 275 nm. These peaks were concentrated by AgNO3-silicic acid column chromatography and reversed-phase HPLC. The structural analysis, o...

  14. Block-conjugate-gradient method

    International Nuclear Information System (INIS)

    McCarthy, J.F.

    1989-01-01

    It is shown that by using the block-conjugate-gradient method several, say s, columns of the inverse Kogut-Susskind fermion matrix can be found simultaneously, in less time than it would take to run the standard conjugate-gradient algorithm s times. The method improves in efficiency relative to the standard conjugate-gradient algorithm as the fermion mass is decreased and as the value of the coupling is pushed to its limit before the finite-size effects become important. Thus it is potentially useful for measuring propagators in large lattice-gauge-theory calculations of the particle spectrum

  15. [Evaluation of safety of haemophilus influenza type b(Hib) conjugate vaccine in postmarketing based on the immunization information management system].

    Science.gov (United States)

    Wang, Zhiguo; Ma, Fubao; Zhang, Jinlin; Yu, Jing; Kang, Guodong; Gao, Jun

    2015-06-01

    To analyze the occurrence feature of adverse events following immunization (AEFI) of Hib conjugate vaccine (HibCV) and to evaluate the safety of HibCV in postmarketing. 2008-2013 HibCV AEFI data were collected through national AEFI information management system, which were downloaded in March 18, 2014.The demographic information and inoculation quantity of HibCV were from Immunization information management system in Jiangsu province. The incidence rate and 95% CI value of AEFI, common vaccine reaction and rare vaccine reaction following immunization of HibCV were calculated. The differences in the incidence rate of common vaccine reaction and rare vaccine reaction among sex, months of age, and number of injections were compared by means of (χ² tests. A total of 6.16 million doses of vaccine were administered in Jiangsu province during 2008-2013, and 4 718 vaccinees reported having adverse event, for a rate of 76.60/100 000 (95% CI: 74.42/100 000-78.79/100 000). The incidence rate of common vaccine reaction and rare vaccine reaction was 71.10/100 000 (95% CI: 68.99/100 000-73.20/100 000) and 5.16/100 000 (95% CI: 4.60/100 000-5.73/100 000), respectively. The main symptoms of common vaccine reactions were fever, swelling, indurations and gastrointestinal reactions. The incidence rates of them were 40.54/100 000, 35.09/100 000, 12.94/100 000 and 0.36/100 000 in turn. The main symptoms of rare vaccine reactions were anaphylactic rashes and angioedema, the incidence rates of which were 4.77/100 000 and 0.15/100 000 respectively. 91.39% (4 002/4 379) of common vaccine reactions and 88.36% (281/318) of rare vaccine reactions happened within 1 d after vaccination. Anaphylactic shock (3 cases) and laryngeal edema (1 case) all happened within 1 d after vaccination. The incidence rate of common vaccine reactions among boys (79.72/100 000, 2 641/3 313 071) was higher than that of girls (61.07/100 000, 1 738/2 846 001) (χ² = 74.92, P < 0.001). The incidence rate of common

  16. Less is More: A Comparison of Antibody-Gold Nanoparticle Conjugates of Different Ratios.

    Science.gov (United States)

    Byzova, Nadezhda A; Safenkova, Irina V; Slutskaya, Elvira S; Zherdev, Anatoly V; Dzantiev, Boris B

    2017-11-15

    This comprehensive study is related to gold nanoparticles (GNPs) conjugated with antibodies. The goal of the study is to determine the minimal concentration of antibodies for conjugate synthesis when the conjugates have high antigen-capturing activity. Two systems were studied: gold nanoparticles conjugated with monoclonal antibodies (mAb-GNP) specific to Helicobacter pylori and gold nanoparticles conjugated with polyclonal antibodies (pAb-GNP) specific to mouse immunoglobulins. Several conjugates were synthesized with different GNP-to-antibody molar ratios (from 1:1 to 1:245) through nondirectional and noncovalent immobilization on a surface of GNPs with a diameter of 25.3 ± 4.6 nm. The maximal antigen-capturing activities and equilibrium constants of the conjugates correlate with the formation of a constant hydrodynamic radius of the conjugates for mAb-GNP (GNP to antibody molar ratio 1:58) and with the stabilizing concentration by flocculation curves for pAb-GNP (GNP to antibody molar ratio 1:116). The application of the conjugates to the lateral flow immunoassay shows that the antibody concentrations used for the conjugation can be reduced (below the stabilizing concentration) without losing activity for the mAb-GNP conjugates. The findings highlight that the optimal concentration of antibodies immobilized on the surface of GNPs is not always equal to the stabilizing concentration determined by the flocculation curve.

  17. Studying p53 family proteins in yeast: Induction of autophagic cell death and modulation by interactors and small molecules

    Energy Technology Data Exchange (ETDEWEB)

    Leão, Mariana; Gomes, Sara; Bessa, Cláudia; Soares, Joana; Raimundo, Liliana [REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 164, 4050-313 Porto (Portugal); Monti, Paola; Fronza, Gilberto [Mutagenesis Unit, Istituto di Ricerca e Cura a Carattere Scientifico Azienda Ospedaliera Universitaria San Martino-IST-Istituto Nazionale per la Ricerca sul Cancro, 16132 Genoa (Italy); Pereira, Clara [REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 164, 4050-313 Porto (Portugal); Saraiva, Lucília, E-mail: lucilia.saraiva@ff.up.pt [REQUIMTE, Laboratório de Microbiologia, Departamento de Ciências Biológicas, Faculdade de Farmácia, Universidade do Porto, Rua de Jorge Viterbo Ferreira n. 164, 4050-313 Porto (Portugal)

    2015-01-01

    In this work, the yeast Saccharomyces cerevisiae was used to individually study human p53, p63 (full length and truncated forms) and p73. Using this cell system, the effect of these proteins on cell proliferation and death, and the influence of MDM2 and MDMX on their activities were analyzed. When expressed in yeast, wild-type p53, TAp63, ΔNp63 and TAp73 induced growth inhibition associated with S-phase cell cycle arrest. This growth inhibition was accompanied by reactive oxygen species production and autophagic cell death. Furthermore, they stimulated rapamycin-induced autophagy. On the contrary, none of the tested p53 family members induced apoptosis either per se or after apoptotic stimuli. As previously reported for p53, also TAp63, ΔNp63 and TAp73 increased actin expression levels and its depolarization, suggesting that ACT1 is also a p63 and p73 putative yeast target gene. Additionally, MDM2 and MDMX inhibited the activity of all tested p53 family members in yeast, although the effect was weaker on TAp63. Moreover, Nutlin-3a and SJ-172550 were identified as potential inhibitors of the p73 interaction with MDM2 and MDMX, respectively. Altogether, the yeast-based assays herein developed can be envisaged as a simplified cell system to study the involvement of p53 family members in autophagy, the modulation of their activities by specific interactors (MDM2 and MDMX), and the potential of new small molecules to modulate these interactions. - Highlights: • p53, p63 and p73 are individually studied in the yeast S. cerevisiae. • p53 family members induce ROS production, cell cycle arrest and autophagy in yeast. • p53 family members increase actin depolarization and expression levels in yeast. • MDM2 and MDMX inhibit the activity of p53 family members in yeast. • Yeast can be a useful tool to study the biology and drugability of p53, p63 and p73.

  18. Studying p53 family proteins in yeast: Induction of autophagic cell death and modulation by interactors and small molecules

    International Nuclear Information System (INIS)

    Leão, Mariana; Gomes, Sara; Bessa, Cláudia; Soares, Joana; Raimundo, Liliana; Monti, Paola; Fronza, Gilberto; Pereira, Clara; Saraiva, Lucília

    2015-01-01

    In this work, the yeast Saccharomyces cerevisiae was used to individually study human p53, p63 (full length and truncated forms) and p73. Using this cell system, the effect of these proteins on cell proliferation and death, and the influence of MDM2 and MDMX on their activities were analyzed. When expressed in yeast, wild-type p53, TAp63, ΔNp63 and TAp73 induced growth inhibition associated with S-phase cell cycle arrest. This growth inhibition was accompanied by reactive oxygen species production and autophagic cell death. Furthermore, they stimulated rapamycin-induced autophagy. On the contrary, none of the tested p53 family members induced apoptosis either per se or after apoptotic stimuli. As previously reported for p53, also TAp63, ΔNp63 and TAp73 increased actin expression levels and its depolarization, suggesting that ACT1 is also a p63 and p73 putative yeast target gene. Additionally, MDM2 and MDMX inhibited the activity of all tested p53 family members in yeast, although the effect was weaker on TAp63. Moreover, Nutlin-3a and SJ-172550 were identified as potential inhibitors of the p73 interaction with MDM2 and MDMX, respectively. Altogether, the yeast-based assays herein developed can be envisaged as a simplified cell system to study the involvement of p53 family members in autophagy, the modulation of their activities by specific interactors (MDM2 and MDMX), and the potential of new small molecules to modulate these interactions. - Highlights: • p53, p63 and p73 are individually studied in the yeast S. cerevisiae. • p53 family members induce ROS production, cell cycle arrest and autophagy in yeast. • p53 family members increase actin depolarization and expression levels in yeast. • MDM2 and MDMX inhibit the activity of p53 family members in yeast. • Yeast can be a useful tool to study the biology and drugability of p53, p63 and p73

  19. Fast optimal wavefront reconstruction for multi-conjugate adaptive optics using the Fourier domain preconditioned conjugate gradient algorithm.

    Science.gov (United States)

    Vogel, Curtis R; Yang, Qiang

    2006-08-21

    We present two different implementations of the Fourier domain preconditioned conjugate gradient algorithm (FD-PCG) to efficiently solve the large structured linear systems that arise in optimal volume turbulence estimation, or tomography, for multi-conjugate adaptive optics (MCAO). We describe how to deal with several critical technical issues, including the cone coordinate transformation problem and sensor subaperture grid spacing. We also extend the FD-PCG approach to handle the deformable mirror fitting problem for MCAO.

  20. Acupuncture promotes mTOR-independent autophagic clearance of aggregation-prone proteins in mouse brain.

    Science.gov (United States)

    Tian, Tian; Sun, Yanhong; Wu, Huangan; Pei, Jian; Zhang, Jing; Zhang, Yi; Wang, Lu; Li, Bin; Wang, Lihua; Shi, Jiye; Hu, Jun; Fan, Chunhai

    2016-01-21

    Acupuncture has historically been practiced to treat medical disorders by mechanically stimulating specific acupoints with fine needles. Despite its well-documented efficacy, its biological basis remains largely elusive. In this study, we found that mechanical stimulation at the acupoint of Yanglingquan (GB34) promoted the autophagic clearance of α-synuclein (α-syn), a well known aggregation-prone protein closely related to Parkinson's disease (PD), in the substantia nigra par compacta (SNpc) of the brain in a PD mouse model. We found the protein clearance arose from the activation of the autophagy-lysosome pathway (ALP) in a mammalian target of rapamycin (mTOR)-independent approach. Further, we observed the recovery in the activity of dopaminergic neurons in SNpc, and improvement in the motor function at the behavior level of PD mice. Whereas acupuncture and rapamycin, a chemical mTOR inhibitor, show comparable α-syn clearance and therapeutic effects in the PD mouse model, the latter adopts a distinctly different, mTOR-dependent, autophagy induction process. Due to this fundamental difference, acupuncture may circumvent adverse effects of the rapamycin treatment. The newly discovered connection between acupuncture and autophagy not only provides a new route to understanding the molecular mechanism of acupuncture but also sheds new light on cost-effective and safe therapy of neurodegenerative diseases.

  1. Ethambutol induces impaired autophagic flux and apoptosis in the rat retina

    Directory of Open Access Journals (Sweden)

    Shun-Ping Huang

    2015-08-01

    Full Text Available Ethambutol (EMB, an effective first-line antituberculosis agent, can cause serious visual impairment or irreversible vision loss in a significant number of patients. However, the mechanism underlying this ocular cytotoxicity remains to be elucidated. In this study, we found that there were statistically significant dose- and time-dependent increases in the number of cytoplasmic vacuoles and the level of cell death in EMB-treated RGC-5 cells (retinal ganglion cells. The protein kinase C (PKCδ inhibitor rottlerin markedly reduced the EMB-induced activation of caspase-3 and the subsequent apoptosis of RGC-5 cells. Western blot analysis revealed that the expression levels of class III PI3K, Beclin-1, p62 and LC3-II were upregulated, and LC3 immunostaining results showed activation of the early phase and inhibition of the late stage of autophagy in retinas of the EMB-intraperitoneal (IP-injected rat model. We further demonstrated that exposure to EMB induces autophagosome accumulation, which results from the impaired autophagic flux that is mediated by a PKCδ-dependent pathway, inhibits the PI3K/Akt/mTOR signaling pathway and leads to apoptotic death in retina neuronal cells. These results indicate that autophagy dysregulation in retinal neuronal cells might play a substantial role in EMB-induced optic neuroretinopathy.

  2. HAMLET (human alpha-lactalbumin made lethal to tumor cells) triggers autophagic tumor cell death.

    Science.gov (United States)

    Aits, Sonja; Gustafsson, Lotta; Hallgren, Oskar; Brest, Patrick; Gustafsson, Mattias; Trulsson, Maria; Mossberg, Ann-Kristin; Simon, Hans-Uwe; Mograbi, Baharia; Svanborg, Catharina

    2009-03-01

    HAMLET, a complex of partially unfolded alpha-lactalbumin and oleic acid, kills a wide range of tumor cells. Here we propose that HAMLET causes macroautophagy in tumor cells and that this contributes to their death. Cell death was accompanied by mitochondrial damage and a reduction in the level of active mTOR and HAMLET triggered extensive cytoplasmic vacuolization and the formation of double-membrane-enclosed vesicles typical of macroautophagy. In addition, HAMLET caused a change from uniform (LC3-I) to granular (LC3-II) staining in LC3-GFP-transfected cells reflecting LC3 translocation during macroautophagy, and this was blocked by the macroautophagy inhibitor 3-methyladenine. HAMLET also caused accumulation of LC3-II detected by Western blot when lysosomal degradation was inhibited suggesting that HAMLET caused an increase in autophagic flux. To determine if macroautophagy contributed to cell death, we used RNA interference against Beclin-1 and Atg5. Suppression of Beclin-1 and Atg5 improved the survival of HAMLET-treated tumor cells and inhibited the increase in granular LC3-GFP staining. The results show that HAMLET triggers macroautophagy in tumor cells and suggest that macroautophagy contributes to HAMLET-induced tumor cell death.

  3. Endo-lysosomal and autophagic dysfunction: a driving factor in Alzheimer's disease?

    Science.gov (United States)

    Whyte, Lauren S; Lau, Adeline A; Hemsley, Kim M; Hopwood, John J; Sargeant, Timothy J

    2017-03-01

    Alzheimer's disease (AD) is the most common cause of dementia, and its prevalence will increase significantly in the coming decades. Although important progress has been made, fundamental pathogenic mechanisms as well as most hereditary contributions to the sporadic form of the disease remain unknown. In this review, we examine the now substantial links between AD pathogenesis and lysosomal biology. The lysosome hydrolyses and processes cargo delivered by multiple pathways, including endocytosis and autophagy. The endo-lysosomal and autophagic networks are central to clearance of cellular macromolecules, which is important given there is a deficit in clearance of amyloid-β in AD. Numerous studies show prominent lysosomal dysfunction in AD, including perturbed trafficking of lysosomal enzymes and accumulation of the same substrates that accumulate in lysosomal storage disorders. Examination of the brain in lysosomal storage disorders shows the accumulation of amyloid precursor protein metabolites, which further links lysosomal dysfunction with AD. This and other evidence leads us to hypothesise that genetic variation in lysosomal genes modifies the disease course of sporadic AD. © 2016 International Society for Neurochemistry.

  4. Evaluation of the Cytotoxic and Autophagic Effects of Atorvastatin on MCF-7 Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Tuğba Alarcon Martinez

    2018-05-01

    Full Text Available Background: Recently, cytotoxic effects of statins on breast cancer cells have been reported. However, the mechanism of anti-proliferative effects is currently unknown. Autophagy is non-apoptotic programmed cell death, which is characterized by degradation of cytoplasmic components and as having a role in cancer pathogenesis. Aims: To investigate the anti-proliferative effects of atorvastatin on MCF-7 human breast adenocarcinoma cells with respect to both autophagy and apoptosis. Study Design: Cell culture study. Methods: Cell viability was analyzed using WST-1 cell proliferation assay. Apoptosis was determined by the TUNEL method, whereas autophagy was assessed by Beclin-1 and LC3B immunofluorescence staining. Ultrastructural analysis of cells was performed by electron microscopy. Results: Atorvastatin reduced MCF-7 cell proliferation in a dose- and time-dependent manner inducing TUNEL-, Beclin-1-, and LC3B-positive cells. Moreover, ultrastructural analysis showed apoptotic, autophagic, and necrotic morphological changes in treatment groups. A statistically significant increase in the apoptotic index was detected with higher concentrations of atorvastatin at 24 h and 48 h (p<0.05. Conclusion: The anti-proliferative effects of atorvastatin on breast cancer cells is mediated by the induction of both apoptosis and autophagy which shows statins as a potential treatment option for breast cancer.

  5. Eclalbasaponin II induces autophagic and apoptotic cell death in human ovarian cancer cells

    Directory of Open Access Journals (Sweden)

    Yoon Jin Cho

    2016-09-01

    Full Text Available Triterpenoids echinocystic acid and its glycosides, isolated from several Eclipta prostrata, have been reported to possess various biological activities such as anti-inflammatory, anti-bacterial, and anti-diabetic activity. However, the cytotoxicity of the triterpenoids in human cancer cells and their molecular mechanism of action are poorly understood. In the present study, we found that eclalbasaponin II with one glucose moiety has potent cytotoxicity in three ovarian cancer cells and two endometrial cancer cells compared to an aglycone echinocystic acid and eclalbasaponin I with two glucose moiety. Eclalbasaponin II treatment dose-dependently increased sub G1 population. Annexin V staining revealed that eclalbasaponin II induced apoptosis in SKOV3 and A2780 ovarian cancer cells. In addition, eclalbasaponin II-induced cell death was associated with characteristics of autophagy; an increase in acidic vesicular organelle content and elevation of the levels of LC3-II. Interestingly, autophagy inhibitor BaF1 suppressed the eclalbasaponin II-induced apoptosis. Moreover, eclalbasaponin II activated JNK and p38 signaling and inhibited the mTOR signaling. We further demonstrated that pre-treatment with a JNK and p38 inhibitor and mTOR activator attenuated the eclalbasaponin II-induced autophagy. This suggests that eclalbasaponin II induces apoptotic and autophagic cell death through the regulation of JNK, p38, and mTOR signaling in human ovarian cancer cells.

  6. Autophagic degradation of aquaporin-2 is an early event in hypokalemia-induced nephrogenic diabetes insipidus.

    Science.gov (United States)

    Khositseth, Sookkasem; Uawithya, Panapat; Somparn, Poorichaya; Charngkaew, Komgrid; Thippamom, Nattakan; Hoffert, Jason D; Saeed, Fahad; Michael Payne, D; Chen, Shu-Hui; Fenton, Robert A; Pisitkun, Trairak

    2015-12-17

    Hypokalemia (low serum potassium level) is a common electrolyte imbalance that can cause a defect in urinary concentrating ability, i.e., nephrogenic diabetes insipidus (NDI), but the molecular mechanism is unknown. We employed proteomic analysis of inner medullary collecting ducts (IMCD) from rats fed with a potassium-free diet for 1 day. IMCD protein quantification was performed by mass spectrometry using a label-free methodology. A total of 131 proteins, including the water channel AQP2, exhibited significant changes in abundance, most of which were decreased. Bioinformatic analysis revealed that many of the down-regulated proteins were associated with the biological processes of generation of precursor metabolites and energy, actin cytoskeleton organization, and cell-cell adhesion. Targeted LC-MS/MS and immunoblotting studies further confirmed the down regulation of 18 selected proteins. Electron microscopy showed autophagosomes/autophagolysosomes in the IMCD cells of rats deprived of potassium for only 1 day. An increased number of autophagosomes was also confirmed by immunofluorescence, demonstrating co-localization of LC3 and Lamp1 with AQP2 and several other down-regulated proteins in IMCD cells. AQP2 was also detected in autophagosomes in IMCD cells of potassium-deprived rats by immunogold electron microscopy. Thus, enhanced autophagic degradation of proteins, most notably including AQP2, is an early event in hypokalemia-induced NDI.

  7. Entanglements in Conjugated Polymers

    Science.gov (United States)

    Xie, Renxuan; Lee, Youngmin; Aplan, Melissa; Caggiano, Nick; Gomez, Enrique; Colby, Ralph

    Conjugated polymers, such as poly(3-hexylthiophene-2,5-diyl) (P3HT) and poly-((9,9-dioctylfluorene)-2,7-diyl-alt-[4,7-bis(thiophen-5-yl)-2,1,3-benzothiadiazole]-2',2''-diyl) (PFTBT), are widely used as hole and electron transport materials in a variety of electronic devices. However, fundamental knowledge regarding chain entanglements and nematic-to-isotropic transition is still lacking and are crucial to maximize charge transport properties. A systematic melt rheology study on P3HT with various molecular weights and regio regularities was performed. We find that the entanglement molecular weight Me is 5.0 kg/mol for regiorandom P3HT, but the apparent Me for regioregular P3HT is significantly higher. The difference is postulated to arise from the presence of a nematic phase only in regioregular P3HT. Analogously, PFTBT shows a clear rheological signature of the nematic-to-isotropic transition as a reversible sharp transition at 278 C. Shearing of this nematic phase leads to anisotropic crystalline order in PFTBT. We postulate that aligning the microstructure will impact charge transport and thereby advance the field of conducting polymers. National Science Foundation.

  8. Protein carriers of conjugate vaccines: characteristics, development, and clinical trials.

    Science.gov (United States)

    Pichichero, Michael E

    2013-12-01

    The immunogenicity of polysaccharides as human vaccines was enhanced by coupling to protein carriers. Conjugation transformed the T cell-independent polysaccharide vaccines of the past to T cell-dependent antigenic vaccines that were much more immunogenic and launched a renaissance in vaccinology. This review discusses the conjugate vaccines for prevention of infections caused by Hemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis. Specifically, the characteristics of the proteins used in the construction of the vaccines including CRM, tetanus toxoid, diphtheria toxoid, Neisseria meningitidis outer membrane complex, and Hemophilus influenzae protein D are discussed. The studies that established differences among and key features of conjugate vaccines including immunologic memory induction, reduction of nasopharyngeal colonization and herd immunity, and antibody avidity and avidity maturation are presented. Studies of dose, schedule, response to boosters, of single protein carriers with single and multiple polysaccharides, of multiple protein carriers with multiple polysaccharides and conjugate vaccines administered concurrently with other vaccines are discussed along with undesirable consequences of conjugate vaccines. The clear benefits of conjugate vaccines in improving the protective responses of the immature immune systems of young infants and the senescent immune systems of the elderly have been made clear and opened the way to development of additional vaccines using this technology for future vaccine products.

  9. The effect of changes in π-conjugated terthienyl systems using thienyl and ethylenedioxybenzene functionalized thieno[3,4-b]pyrazine precursors: Multicolored low band gap polymers

    International Nuclear Information System (INIS)

    Tarkuc, Simge; Unver, Elif Kose; Udum, Yasemin Arslan; Tanyeli, Cihangir; Toppare, Levent

    2010-01-01

    New classes of thieno[3,4-b]pyrazines containing thienyl and ethylenedioxy phenyl units on electron-withdrawing moieties of π-conjugated terthienyl were synthesized. The effect of structural differences on electrochemical and optoelectronic properties of the resulting polymers was investigated. Changes in the electronic nature of the functional groups enable to tune the electrochemical properties of the π-conjugated terthienyl monomers by lowering oxidation potential from 0.62 V (DTTP) to 0.56 V (DBTP). Spectroelectrochemical analyses revealed that the neutral polymer (PDBTP) is dark green in its neutral state revealing π-π* transitions in two well-separated bands at 410 and 751 nm. The electronic band gap of polymer, defined as the onset of the π-π* transition, is found to be 1.0 eV. Using the thienyl unit instead of ethylenedioxy phenyl, a red shift in the band gap (0.95 eV) is observed. The polymer, PDTTP, exhibits multicolor electrochromism and can be switched between a dark yellow neutral state, a green intermediate state, and a brown oxidized state. PDBTP also shows a multicolored electrochromic behavior with three distinct states: dark green at the neutral state, a brown intermediate state, and a brown-violet oxidized state.

  10. Chemo-enzymatic Synthesis of Propionyl-ester-linked Taxol-monosaccharide Conjugate and its Drug Delivery System Using Hybrid-Bio-nanocapsules Targeting Brain Glioma Cells

    Directory of Open Access Journals (Sweden)

    Hiroki Hamada

    2013-01-01

    Full Text Available Taxol is recognized as one of the most potent anticancer agents used in the treatment of breast and ovarian cancers, which are common cancers in women. To overcome its shortcomings, that is, its low water-solubility that reduces drug loading capacity of DDS carriers when incorporating taxol, chemo-enzymatic synthesis of ester-linked taxol-glucose conjugate, i.e., 7-propionyltaxol 2′- O -α-D-glucoside, as a water soluble taxol prodrug was achieved by using a-glucosidase as a glucosylation catalyst. The water-solubility of 7-propionyltaxol 2′- O -α-D-glucoside (25 mM was 63 fold higher than that of taxol (0.4 mM. The pre-S1 peptide which displays on the surface of bio-nanocapsules, which are nanoparticles composed of the hepatitis B virus surface antigen, was replaced with the antibody affinity motif of protein A. Conjugation of such bio-nanocapsules with anti-human epidermal growth factor receptor antibody gave hybrid bio-nanocapsules. The hybrid bio-nanocapsules were effective for delivering 7-propionyltaxol 2′- O -α-D-glucoside to human brain glioma cells. 7-Propionyltaxol 2′- O -α-D-glucoside was effectively hydrolyzed to give taxol in 95% by human glioma cells. The drug loading capacity of hybrid bio-nanocapsules incorporating 7-propionyltaxol 2′- O -α-D-glucoside was 120 times higher than that incorporating taxol itself.

  11. Conjugated Fatty Acid Synthesis

    Science.gov (United States)

    Rawat, Richa; Yu, Xiao-Hong; Sweet, Marie; Shanklin, John

    2012-01-01

    Conjugated linolenic acids (CLNs), 18:3 Δ9,11,13, lack the methylene groups found between the double bonds of linolenic acid (18:3 Δ9,12,15). CLNs are produced by conjugase enzymes that are homologs of the oleate desaturases FAD2. The goal of this study was to map the domain(s) within the Momordica charantia conjugase (FADX) responsible for CLN formation. To achieve this, a series of Momordica FADX-Arabidopsis FAD2 chimeras were expressed in the Arabidopsis fad3fae1 mutant, and the transformed seeds were analyzed for the accumulation of CLN. These experiments identified helix 2 and the first histidine box as a determinant of conjugase product partitioning into punicic acid (18:3 Δ9cis,11trans,13cis) or α-eleostearic acid (18:3 Δ9cis,11trans,13trans). This was confirmed by analysis of a FADX mutant containing six substitutions in which the sequence of helix 2 and first histidine box was converted to that of FAD2. Each of the six FAD2 substitutions was individually converted back to the FADX equivalent identifying residues 111 and 115, adjacent to the first histidine box, as key determinants of conjugase product partitioning. Additionally, expression of FADX G111V and FADX G111V/D115E resulted in an approximate doubling of eleostearic acid accumulation to 20.4% and 21.2%, respectively, compared with 9.9% upon expression of the native Momordica FADX. Like the Momordica conjugase, FADX G111V and FADX D115E produced predominantly α-eleostearic acid and little punicic acid, but the FADX G111V/D115E double mutant produced approximately equal amounts of α-eleostearic acid and its isomer, punicic acid, implicating an interactive effect of residues 111 and 115 in punicic acid formation. PMID:22451660

  12. Autophagic clearance of mitochondria in the kidney copes with metabolic acidosis.

    Science.gov (United States)

    Namba, Tomoko; Takabatake, Yoshitsugu; Kimura, Tomonori; Takahashi, Atsushi; Yamamoto, Takeshi; Matsuda, Jun; Kitamura, Harumi; Niimura, Fumio; Matsusaka, Taiji; Iwatani, Hirotsugu; Matsui, Isao; Kaimori, Junya; Kioka, Hidetaka; Isaka, Yoshitaka; Rakugi, Hiromi

    2014-10-01

    Metabolic acidosis, a common complication of CKD, causes mitochondrial stress by undefined mechanisms. Selective autophagy of impaired mitochondria, called mitophagy, contributes toward maintaining cellular homeostasis in various settings. We hypothesized that mitophagy is involved in proximal tubular cell adaptations to chronic metabolic acidosis. In transgenic mice expressing green fluorescent protein-tagged microtubule-associated protein 1 light chain 3 (GFP-LC3), NH4Cl loading increased the number of GFP puncta exclusively in the proximal tubule. In vitro, culture in acidic medium produced similar results in proximal tubular cell lines stably expressing GFP-LC3 and facilitated the degradation of SQSTM1/p62 in wild-type cells, indicating enhanced autophagic flux. Upon acid loading, proximal tubule-specific autophagy-deficient (Atg5-deficient) mice displayed significantly reduced ammonium production and severe metabolic acidosis compared with wild-type mice. In vitro and in vivo, acid loading caused Atg5-deficient proximal tubular cells to exhibit reduced mitochondrial respiratory chain activity, reduced mitochondrial membrane potential, and fragmented morphology with marked swelling in mitochondria. GFP-LC3-tagged autophagosomes colocalized with ubiquitinated mitochondria in proximal tubular cells cultured in acidic medium, suggesting that metabolic acidosis induces mitophagy. Furthermore, restoration of Atg5-intact nuclei in Atg5-deficient proximal tubular cells increased mitochondrial membrane potential and ammoniagenesis. In conclusion, metabolic acidosis induces autophagy in proximal tubular cells, which is indispensable for maintaining proper mitochondrial functions including ammoniagenesis, and thus for adapted urinary acid excretion. Our results provide a rationale for the beneficial effect of alkali supplementation in CKD, a condition in which autophagy may be reduced, and suggest a new therapeutic option for acidosis by modulating autophagy. Copyright

  13. ATG13: just a companion, or an executor of the autophagic program?

    Science.gov (United States)

    Alers, Sebastian; Wesselborg, Sebastian; Stork, Björn

    2014-06-01

    During the past 20 years, autophagy signaling has entered the main stage of the cell biological theater. Autophagy represents an intracellular degradation process that is involved in both the bulk recycling of cytoplasmic components and the selective removal of organelles, protein aggregates, or intracellular pathogens. The understanding of autophagy has been greatly facilitated by the characterization of the molecular machinery governing this process. In yeast, initiation of autophagy is controlled by the Atg1 kinase complex, which is composed of the Ser/Thr kinase Atg1, the adaptor protein Atg13, and the ternary complex of Atg17-Atg31-Atg29. In vertebrates, the orthologous ULK1 kinase complex contains the Ser/Thr kinase ULK1 and the accessory proteins ATG13, RB1CC1, and ATG101. Among these components, Atg1/ULK1 have gained major attention in the past, i.e., for the identification of upstream regulatory kinases, the characterization of downstream substrates controlling the autophagic flux, or as a druggable target for the modulation of autophagy. However, accumulating data indicate that the function of Atg13/ATG13 has been likely underestimated so far. In addition to ensuring proper Atg1/ULK1 recruitment and activity, this adaptor molecule has been implicated in ULK1-independent autophagy processes. Furthermore, recent data have identified additional binding partners of Atg13/ATG13 besides the components of the Atg1/ULK1 complex, e.g., Atg8 family proteins or acidic phospholipids. Therefore, in this review we will center the spotlight on Atg13/ATG13 and summarize the role that Atg13/ATG13 assumes in the autophagy stage play.

  14. Autophagic lysosome reformation dysfunction in glucocerebrosidase deficient cells: relevance to Parkinson disease.

    Science.gov (United States)

    Magalhaes, Joana; Gegg, Matthew E; Migdalska-Richards, Anna; Doherty, Mary K; Whitfield, Phillip D; Schapira, Anthony H V

    2016-08-15

    Glucocerebrosidase (GBA1) gene mutations increase the risk of Parkinson disease (PD). While the cellular mechanisms associating GBA1 mutations and PD are unknown, loss of the glucocerebrosidase enzyme (GCase) activity, inhibition of autophagy and increased α-synuclein levels have been implicated. Here we show that autophagy lysosomal reformation (ALR) is compromised in cells lacking functional GCase. ALR is a cellular process controlled by mTOR which regenerates functional lysosomes from autolysosomes formed during macroautophagy. A decrease in phopho-S6K levels, a marker of mTOR activity, was observed in models of GCase deficiency, including primary mouse neurons and the PD patient derived fibroblasts with GBA1 mutations, suggesting that ALR is compromised. Importantly Rab7, a GTPase crucial for endosome-lysosome trafficking and ALR, accumulated in GCase deficient cells, supporting the notion that lysosomal recycling is impaired. Recombinant GCase treatment reversed ALR inhibition and lysosomal dysfunction. Moreover, ALR dysfunction was accompanied by impairment of macroautophagy and chaperone-mediated autophagy, increased levels of total and phosphorylated (S129) monomeric α-synuclein, evidence of amyloid oligomers and increased α-synuclein release. Concurrently, we found increased cholesterol and altered glucosylceramide homeostasis which could compromise ALR. We propose that GCase deficiency in PD inhibits lysosomal recycling. Consequently neurons are unable to maintain the pool of mature and functional lysosomes required for the autophagic clearance of α-synuclein, leading to the accumulation and spread of pathogenic α-synuclein species in the brain. Since GCase deficiency and lysosomal dysfunction occur with ageing and sporadic PD pathology, the decrease in lysosomal reformation may be a common feature in PD. © The Author 2016. Published by Oxford University Press.

  15. Intense pseudotransport of a cationic drug mediated by vacuolar ATPase: Procainamide-induced autophagic cell vacuolization

    International Nuclear Information System (INIS)

    Morissette, Guillaume; Lodge, Robert; Marceau, Francois

    2008-01-01

    Cationic drugs frequently exhibit large apparent volumes of distribution, consistent with various forms of cellular sequestration. The contributions of organelles and metabolic processes that may mimic drug transport were defined in human vascular smooth muscle cells. We hypothesized that procainamide-induced vacuolar cytopathology is driven by intense pseudotransport mediated by the vacuolar (V)-ATPase and pursued the characterization of vesicular trafficking alterations in this model. Large amounts of procainamide were taken up by intact cells (maximal in 2 h, reversible upon washout, apparent K M 4.69 mM; fluorometric determination of cell-associated drug). Procainamide uptake was extensively prevented or reversed by pharmacological inhibition of the V-ATPase with bafilomycin A1 or FR 167356, decreased at low extracellular pH and preceded vacuolar cell morphology. However, the uptake of procainamide was unaffected by mitochondrial poisons that reduced the uptake of rhodamine 6G. Large vacuoles induced by millimolar procainamide were labeled with the late endosome/lysosome markers Rab7 and CD63 and the autophagy effector LC3; their osmotic formation (but not procainamide uptake) was reduced by extracellular mannitol and parallel to LC3 II formation. Procainamide-induced vacuolization is associated with defective endocytosis of fluorophore-labeled bovine serum albumin, but not with induction of the unfolded protein response. The contents of a vacuole subset slowly (≥ 24 h) become positive for Nile red staining (phospholipidosis-like response). V-ATPase-driven ion trapping is a form of intense cation pseudotransport that concerns the uncharged form of the drugs, and is associated with a vacuolar, autophagic and evolutive cytopathology and profound effects on vesicular trafficking

  16. Research study of conjugate materials; Conjugate material no chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    The paper reported an introductory research on possibilities of new glass `conjugate materials.` The report took up the structure and synthetic process of conjugate materials to be researched/developed, classified them according to structural elements on molecular, nanometer and cluster levels, and introduced the structures and functions. Further, as glasses with new functions to be proposed, the paper introduced transparent and high-strength glass used for houses and vehicles, light modulation glass which realizes energy saving and optical data processing, and environmentally functional glass which realizes environmental cleaning or high performance biosensor. An initial survey was also conducted on rights of intellectual property to be taken notice of in Japan and abroad in the present situation. Reports were summed up and introduced of Osaka National Research Institute, Electrotechnical Laboratory, and National Industrial Research Institute of Nagoya which are all carrying out leading studies of conjugate materials. 235 refs., 135 figs., 6 tabs.

  17. Numerical Modeling of Conjugate Thermogravitational Convection in a Closed System with a Radiant Energy Source in Conditions of Convective-Radiative Heat Exchange at the External Boundary

    Directory of Open Access Journals (Sweden)

    Nee Alexander

    2016-01-01

    Full Text Available Mathematical modeling of conjugate natural convection in a closed rectangular cavity with a radiant energy source in conditions of convective-radiative heat exchange at the external boundary was conducted. The radiant energy distribution was set by the Lambert’s law. Conduction and convection processes analysis showed that the air masses flow pattern is modified slightly over the time. The temperature increases in the gas cavity, despite the heat removal from the one of the external boundary. According to the results of the integral heat transfer analysis were established that the average Nusselt number (Nuav increasing occurs up to τ = 200 (dimensionless time. Further Nuav has changed insignificantly due to the temperature field equalization near the interfaces “gas – wall”.

  18. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi

    2017-03-16

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  19. Conjugated polymer nanoparticles, methods of using, and methods of making

    KAUST Repository

    Habuchi, Satoshi; Piwonski, Hubert Marek; Michinobu, Tsuyoshi

    2017-01-01

    Embodiments of the present disclosure provide for conjugated polymer nanoparticle, method of making conjugated polymer nanoparticles, method of using conjugated polymer nanoparticle, polymers, and the like.

  20. Conjugated polymer zwitterions and solar cells comprising conjugated polymer zwitterions

    Science.gov (United States)

    Emrick, Todd; Russell, Thomas; Page, Zachariah; Liu, Yao

    2018-06-05

    A conjugated polymer zwitterion includes repeating units having structure (I), (II), or a combination thereof ##STR00001## wherein Ar is independently at each occurrence a divalent substituted or unsubstituted C3-30 arylene or heteroarylene group; L is independently at each occurrence a divalent C1-16 alkylene group, C6-30arylene or heteroarylene group, or alkylene oxide group; and R1 is independently at each occurrence a zwitterion. A polymer solar cell including the conjugated polymer zwitterion is also disclosed.

  1. Peptide π-Electron Conjugates: Organic Electronics for Biology?

    Science.gov (United States)

    Ardoña, Herdeline Ann M; Tovar, John D

    2015-12-16

    Highly ordered arrays of π-conjugated molecules are often viewed as a prerequisite for effective charge-transporting materials. Studies involving these materials have traditionally focused on organic electronic devices, with more recent emphasis on biological systems. In order to facilitate the transition to biological environments, biomolecules that can promote hierarchical ordering and water solubility are often covalently appended to the π-electron unit. This review highlights recent work on π-conjugated systems bound to peptide moieties that exhibit self-assembly and aims to provide an overview on the development and emerging applications of peptide-based supramolecular π-electron systems.

  2. Polysaccharide from Fuzi protects against Ox-LDL-induced calcification of human vascular smooth muscle cells by increasing autophagic activity

    Science.gov (United States)

    Liao, Lizhen; Zhuang, Xiaodong; Li, Weidong; Su, Qibiao; Zhao, Jie; Liu, Ying

    2018-01-01

    Polysaccharide from Fuzi (FPS) is a water-soluble polysaccharide isolated from the traditional Chinese herbal medicine Fuzi. It has been demonstrated to protect hepatocytes against ischemia-reperfusion injury through its potent antioxidant effects, and to attenuate starvation-induced cytotoxicity in H9c2 cells by increasing autophagic activity. In the present study, Alizarin Red S staining was used to detect mineral deposition and reverse transcription-quantitative polymerase chain reaction was used to detect the core binding factor α1 and smooth muscle 22α mRNA expression. To analyze autophagic activity, western blotting was used to detect microtubule-associated protein 1A/1B light chain 3 and nucleoporin P62 expression. In addition, green fluorescent protein-LC3 dots-per-cell was observed by fluorescence microscopy. It was demonstrated that oxidized low-density lipoprotein (Ox-LDL) could increase the calcification of human vascular smooth muscle cells (VSMCs) in a concentration-dependent manner, and that FPS treatment had a significant protective effect against Ox-LDL-induced calcification of human VSMCs. Furthermore, FPS treatment alleviated the Ox-LDL-induced downregulation of autophagic activity, and the protective effect of FPS on Ox-LDL-induced calcification was attenuated by the autophagy inhibitor 3-methyladenine. In conclusion, the present study demonstrated for the first time to the best of the authors' knowledge that FPS can protect against Ox-LDL-induced vascular calcification in human VSMCs, and that this likely occurs via the activation of autophagy. This supports the hypothesis that autophagy may be an endogenous protective mechanism counteracting vascular calcification, and that FPS may be used as a potential therapeutic for vascular calcification. PMID:29393437

  3. Lysosomotropic cationic drugs induce cytostatic and cytotoxic effects: Role of liposolubility and autophagic flux and antagonism by cholesterol ablation

    Energy Technology Data Exchange (ETDEWEB)

    Parks, Alexandre; Marceau, François, E-mail: francois.marceau@crchul.ulaval.ca

    2016-08-15

    Cation trapping in acidic cell compartments determines an antiproliferative effect that has a potential interest in oncology, as shown by clinical data and trials involving chloroquine and hydroxychloroquine. To further characterize the mechanism of this effect, we studied a series of 6 substituted triethylamine (s-Et{sub 3}N) drugs that encompasses a wide range of liposolubility (amiodarone, quinacrine, chloroquine, hydroxychloroquine, lidocaine, and procainamide). Three tumor cell lines and primary human endothelial cells were exploited in proliferation assays (48 h, cell counts). Accumulation of the autophagic effector LC3 II and the apoptotic marker cleaved PARP1 (immunoblots), cytotoxicity, cell cycle analysis and endocytic function were further tested in the p53-null histiocytic lymphoma U937 line. A profound and desynchronized antiproliferative effect was observed in response to all s-Et{sub 3}Ns with essentially no cell type specificity. Predictors of s-Et{sub 3}N potency were liposolubility and the acute accumulation of the autophagic effector LC3 II (6 h-treatments). For each s-Et{sub 3}N, there was an antiproliferative concentration range where cytotoxicity and apoptosis were not triggered in U937 cells (24–48 h-treatments). Quinacrine was the most potent cytostatic drug (1–5 μM). Co-treatment of cells with inhibitors of cholesterol, β-cyclodextrin or lovastatin, partially reversed the antiproliferative effect of each s-Et{sub 3}N. The cytopathology induced by cationic drug accumulation includes a cytostatic effect. Its intensity is cell type- and p53-independent, but predicted by the inhibition of autophagic flux and by the liposolubility of individual drugs and alleviated by cholesterol ablation. The superiority of quinacrine, biomarker value of LC3 II and antagonism by a statin may be clinically relevant. - Highlights: • Cation trapping in acidic cell compartments induces a cytostatic effect. • A series of substituted triethylamines has been

  4. Interference with the Autophagic Process as a Viral Strategy to Escape from the Immune Control: Lesson from Gamma Herpesviruses

    Directory of Open Access Journals (Sweden)

    Roberta Santarelli

    2015-01-01

    Full Text Available We summarized the most recent findings on the role of autophagy in antiviral immune response. We described how viruses have developed strategies to subvert the autophagic process. A particular attention has been given to Epstein-Barr and Kaposi’s sarcoma associated Herpesvirus, viruses studied for many years in our laboratory. These two viruses belong to γ-Herpesvirus subfamily and are associated with several human cancers. Besides the effects on the immune response, we have described how autophagy subversion by viruses may also concur to the enhancement of their replication and to viral tumorigenesis.

  5. Lysosomotropic cationic drugs induce cytostatic and cytotoxic effects: Role of liposolubility and autophagic flux and antagonism by cholesterol ablation

    International Nuclear Information System (INIS)

    Parks, Alexandre; Marceau, François

    2016-01-01

    Cation trapping in acidic cell compartments determines an antiproliferative effect that has a potential interest in oncology, as shown by clinical data and trials involving chloroquine and hydroxychloroquine. To further characterize the mechanism of this effect, we studied a series of 6 substituted triethylamine (s-Et 3 N) drugs that encompasses a wide range of liposolubility (amiodarone, quinacrine, chloroquine, hydroxychloroquine, lidocaine, and procainamide). Three tumor cell lines and primary human endothelial cells were exploited in proliferation assays (48 h, cell counts). Accumulation of the autophagic effector LC3 II and the apoptotic marker cleaved PARP1 (immunoblots), cytotoxicity, cell cycle analysis and endocytic function were further tested in the p53-null histiocytic lymphoma U937 line. A profound and desynchronized antiproliferative effect was observed in response to all s-Et 3 Ns with essentially no cell type specificity. Predictors of s-Et 3 N potency were liposolubility and the acute accumulation of the autophagic effector LC3 II (6 h-treatments). For each s-Et 3 N, there was an antiproliferative concentration range where cytotoxicity and apoptosis were not triggered in U937 cells (24–48 h-treatments). Quinacrine was the most potent cytostatic drug (1–5 μM). Co-treatment of cells with inhibitors of cholesterol, β-cyclodextrin or lovastatin, partially reversed the antiproliferative effect of each s-Et 3 N. The cytopathology induced by cationic drug accumulation includes a cytostatic effect. Its intensity is cell type- and p53-independent, but predicted by the inhibition of autophagic flux and by the liposolubility of individual drugs and alleviated by cholesterol ablation. The superiority of quinacrine, biomarker value of LC3 II and antagonism by a statin may be clinically relevant. - Highlights: • Cation trapping in acidic cell compartments induces a cytostatic effect. • A series of substituted triethylamines has been studied in 4 cell

  6. {sup 186}Re-maSGS-Z{sub HER2:342}, a potential affibody conjugate for systemic therapy of HER2-expressing tumours

    Energy Technology Data Exchange (ETDEWEB)

    Orlova, Anna; Tran, Thuy A. [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden); Ekblad, Torun; Karlstroem, Amelie Eriksson [Royal Institute of Technology, School of Biotechnology, Division of Molecular Biotechnology, Stockholm (Sweden); Tolmachev, Vladimir [Uppsala University, Division of Biomedical Radiation Sciences, Rudbeck Laboratory, Uppsala (Sweden); Uppsala University, Division of Nuclear Medicine, Department of Medical Sciences, Uppsala (Sweden)

    2010-02-15

    Affibody molecules are a novel class of tumour-targeting proteins, which combine small size (7 kDa) and picomolar affinities. The Affibody molecule Z{sub HER2:342} has been suggested for imaging of HER2 expression in order to select patients for trastuzumab therapy. When optimizing chelators for {sup 99m}Tc-labelling, we have found that synthetic Z{sub HER2:342} conjugated with mercaptoacetyl-glycyl-glycyl-glycyl (maGGG) and mercaptoacetyl-glycyl-seryl-glycyl (maGSG) chelators provides relatively low renal uptake of radioactivity and could be suitable for therapy. maGGG-Z{sub HER2:342} and maGSG-Z{sub HER2:342} were labelled with {sup 186}Re and their biodistribution was studied in normal mice. Dosimetric evaluation and tumour targeting to HER2-overexpressed xenografts (SKOV-3) by {sup 186}Re-maGSG-Z{sub HER2:342} were studied. Gluconate-mediated labelling of maGGG-Z{sub HER2:342} and maGSG-Z{sub HER2:342} with {sup 186}Re provided a yield of more than 95% within 60 min. The conjugates were stable and demonstrated specific binding to HER2-expressing SKOV-3 cells. Biodistribution in normal mice demonstrated rapid blood clearance, low accumulation of radioactivity in the kidney and other organs, accumulating free perrhenate. Both {sup 186}Re-maGGG-Z{sub HER2:342} and {sup 186}Re-maGSG-Z{sub HER2:342} demonstrated lower renal uptake than their {sup 99m}Tc-labelled counterparts. {sup 186}Re-maGSG-Z{sub HER2:342} provided the lowest uptake in healthy tissues. Biodistribution of {sup 186}Re-maGSG-Z{sub HER2:342} in nude mice bearing SKOV-3 xenografts showed specific targeting of tumours. Tumour uptake 24 h after injection (5.84{+-}0.54%ID/g) exceeded the concentration in blood by more than 500-fold, and uptake in kidneys by about 8-fold. Preliminary dosimetric evaluation showed that dose-to-tumour should exceed dose-to-kidney by approximately 5-fold. Optimization of chelators improves biodistribution properties of rhenium-labelled small scaffold proteins and enables

  7. Conjugated polymer photovoltaic devices and materials

    International Nuclear Information System (INIS)

    Mozer, A.J.; Niyazi, Serdar Sariciftci

    2006-01-01

    The science and technology of conjugated polymer-based photovoltaic devices (bulk heterojunction solar cells) is highlighted focusing on three major issues, i.e. (i) nano-morphology optimization, (ii) improving charge carrier mobility, (iii) improving spectral sensitivity. Successful strategies towards improved photovoltaic performance are presented using various novel materials, including double-cable polymers, regioregular polymers and low bandgap polymers. The examples presented herein demonstrate that the bulk heterojunction concept is a viable approach towards developing photovoltaic systems by inexpensive solution-based fabrication technologies. (authors)

  8. Benzyl isothiocyanate causes FoxO1-mediated autophagic death in human breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Dong Xiao

    Full Text Available Benzyl isothiocyanate (BITC, a constituent of edible cruciferous vegetables, inhibits growth of breast cancer cells but the mechanisms underlying growth inhibitory effect of BITC are not fully understood. Here, we demonstrate that BITC treatment causes FoxO1-mediated autophagic death in cultured human breast cancer cells. The BITC-treated breast cancer cells (MDA-MB-231, MCF-7, MDA-MB-468, BT-474, and BRI-JM04 and MDA-MB-231 xenografts from BITC-treated mice exhibited several features characteristic of autophagy, including appearance of double-membrane vacuoles (transmission electron microscopy and acidic vesicular organelles (acridine orange staining, cleavage of microtubule-associated protein 1 light chain 3 (LC3, and/or suppression of p62 (p62/SQSTM1 or sequestosome 1 expression. On the other hand, a normal human mammary epithelial cell line (MCF-10A was resistant to BITC-induced autophagy. BITC-mediated inhibition of MDA-MB-231 and MCF-7 cell viability was partially but statistically significantly attenuated in the presence of autophagy inhibitors 3-methyl adenine and bafilomycin A1. Stable overexpression of Mn-superoxide dismutase, which was fully protective against apoptosis, conferred only partial protection against BITC-induced autophagy. BITC treatment decreased phosphorylation of mTOR and its downstream targets (P70s6k and 4E-BP1 in cultured MDA-MB-231 and MCF-7 cells and MDA-MB-231 xenografts, but activation of mTOR by transient overexpression of its positive regulator Rheb failed to confer protection against BITC-induced autophagy. Autophagy induction by BITC was associated with increased expression and acetylation of FoxO1. Furthermore, autophagy induction and cell growth inhibition resulting from BITC exposure were significantly attenuated by small interfering RNA knockdown of FoxO1. In conclusion, the present study provides novel insights into the molecular circuitry of BITC-induced cell death involving FoxO1-mediated autophagy.

  9. Conjugate adaptive optics with remote focusing in multiphoton microscopy

    Science.gov (United States)

    Tao, Xiaodong; Lam, Tuwin; Zhu, Bingzhao; Li, Qinggele; Reinig, Marc R.; Kubby, Joel

    2018-02-01

    The small correction volume for conventional wavefront shaping methods limits their application in biological imaging through scattering media. In this paper, we take advantage of conjugate adaptive optics (CAO) and remote focusing (CAORF) to achieve three-dimensional (3D) scanning through a scattering layer with a single correction. Our results show that the proposed system can provide 10 times wider axial field of view compared with a conventional conjugate AO system when 16,384 segments are used on a spatial light modulator. We demonstrate two-photon imaging with CAORF through mouse skull. The fluorescent microspheres embedded under the scattering layers can be clearly observed after applying the correction.

  10. Social behaviour and decision making in bacterial conjugation

    Directory of Open Access Journals (Sweden)

    Günther eKoraimann

    2014-04-01

    Full Text Available Bacteria frequently acquire novel genes by HGT (horizontal gene transfer. HGT through the process of bacterial conjugation is highly efficient and depends on the presence of conjugative plasmids (CPs or integrated conjugative elements (ICEs that provide the necessary genes for DNA transmission. This review focuses on recent advancements in our understanding of ssDNA transfer systems and regulatory networks ensuring timely and spatially controlled DNA transfer (tra gene expression. As will become obvious by comparing different systems, by default, tra genes are shut off in cells in which conjugative elements are present. Only when conditions are optimal, donor cells – through epigenetic alleviation of negatively acting roadblocks and direct stimulation of DNA transfer genes – become transfer competent. These transfer competent cells have developmentally transformed into specialized cells capable of secreting ssDNA via a T4S (type IV secretion complex directly into recipient cells. Intriguingly, even under optimal conditions, only a fraction of the population undergoes this transition, a finding that indicates specialization and cooperative, social behavior. Thereby, at the population level, the metabolic burden and other negative consequences of tra gene expression are greatly reduced without compromising the ability to horizontally transfer genes to novel bacterial hosts. This undoubtedly intelligent strategy may explain why conjugative elements – CPs and ICEs – have been successfully kept in and evolved with bacteria to constitute a major driving force of bacterial evolution.

  11. Acute high-caffeine exposure increases autophagic flux and reduces protein synthesis in C2C12 skeletal myotubes.

    Science.gov (United States)

    Hughes, M A; Downs, R M; Webb, G W; Crocker, C L; Kinsey, S T; Baumgarner, Bradley L

    2017-04-01

    Caffeine is a highly catabolic dietary stimulant. High caffeine concentrations (1-10 mM) have previously been shown to inhibit protein synthesis and increase protein degradation in various mammalian cell lines. The purpose of this study was to examine the effect of short-term caffeine exposure on cell signaling pathways that regulate protein metabolism in mammalian skeletal muscle cells. Fully differentiated C2C12 skeletal myotubes either received vehicle (DMSO) or 5 mM caffeine for 6 h. Our analysis revealed that caffeine promoted a 40% increase in autolysosome formation and a 25% increase in autophagic flux. In contrast, caffeine treatment did not significantly increase the expression of the skeletal muscle specific ubiquitin ligases MAFbx and MuRF1 or 20S proteasome activity. Caffeine treatment significantly reduced mTORC1 signaling, total protein synthesis and myotube diameter in a CaMKKβ/AMPK-dependent manner. Further, caffeine promoted a CaMKII-dependent increase in myostatin mRNA expression that did not significantly contribute to the caffeine-dependent reduction in protein synthesis. Our results indicate that short-term caffeine exposure significantly reduced skeletal myotube diameter by increasing autophagic flux and promoting a CaMKKβ/AMPK-dependent reduction in protein synthesis.

  12. Conjugal Pairing in Escherichia Coli

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 8. Conjugal Pairing in Escherichia Coli. Joshua Lederberg. Classics Volume 13 Issue 8 August 2008 pp 793-794. Fulltext. Click here to view fulltext PDF. Permanent link: https://www.ias.ac.in/article/fulltext/reso/013/08/0793-0794 ...

  13. Persistence Mechanisms of Conjugative Plasmids

    DEFF Research Database (Denmark)

    Bahl, Martin Iain; Hansen, Lars H.; Sørensen, Søren Johannes

    2009-01-01

    Are plasmids selfish parasitic DNA molecules or an integrated part of the bacterial genome? This chapter reviews the current understanding of the persistence mechanisms of conjugative plasmids harbored by bacterial cells and populations. The diversity and intricacy of mechanisms affecting the suc...

  14. Orderings for conjugate gradient preconditionings

    Science.gov (United States)

    Ortega, James M.

    1991-01-01

    The effect of orderings on the rate of convergence of the conjugate gradient method with SSOR or incomplete Cholesky preconditioning is examined. Some results also are presented that help to explain why red/black ordering gives an inferior rate of convergence.

  15. REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy ...

    African Journals Online (AJOL)

    REVIEW ARTICLE Conjugated Hyperbilirubinaemia in Early Infancy. AOK Johnson. Abstract. Conjugated hyperbilirubinaemia exists when the conjugated serum bilirubin level is more than 2 mg/dl or more than 20 per cent of the total serum bilirubin. It is always pathological in early infancy. The causes are many and diverse ...

  16. Purification of SUMO conjugating enzymes and kinetic analysis of substrate conjugation

    Science.gov (United States)

    Yunus, Ali A.; Lima, Christopher D.

    2009-01-01

    SUMO conjugation to protein substrates requires the concerted action of a dedicated E2 ubiquitin conjugation enzyme (Ubc9) and associated E3 ligases. Although Ubc9 can directly recognize and modify substrate lysine residues that occur within a consensus site for SUMO modification, E3 ligases can redirect specificity and enhance conjugation rates during SUMO conjugation in vitro and in vivo. In this chapter, we will describe methods utilized to purify SUMO conjugating enzymes and model substrates which can be used for analysis of SUMO conjugation in vitro. We will also describe methods to extract kinetic parameters during E3-dependent or E3-independent substrate conjugation. PMID:19107417

  17. Solar multi-conjugate adaptive optics performance improvement

    Science.gov (United States)

    Zhang, Zhicheng; Zhang, Xiaofang; Song, Jie

    2015-08-01

    In order to overcome the effect of the atmospheric anisoplanatism, Multi-Conjugate Adaptive Optics (MCAO), which was developed based on turbulence correction by means of several deformable mirrors (DMs) conjugated to different altitude and by which the limit of a small corrected FOV that is achievable with AO is overcome and a wider FOV is able to be corrected, has been widely used to widen the field-of-view (FOV) of a solar telescope. With the assistance of the multi-threaded Adaptive Optics Simulator (MAOS), we can make a 3D reconstruction of the distorted wavefront. The correction is applied by one or more DMs. This technique benefits from information about atmospheric turbulence at different layers, which can be used to reconstruct the wavefront extremely well. In MAOS, the sensors are either simulated as idealized wavefront gradient sensors, tip-tilt sensors based on the best Zernike fit, or a WFS using physical optics and incorporating user specified pixel characteristics and a matched filter pixel processing algorithm. Only considering the atmospheric anisoplanatism, we focus on how the performance of a solar MCAO system is related to the numbers of DMs and their conjugate heights. We theoretically quantify the performance of the tomographic solar MCAO system. The results indicate that the tomographic AO system can improve the average Strehl ratio of a solar telescope by only employing one or two DMs conjugated to the optimum altitude. And the S.R. has a significant increase when more deformable mirrors are used. Furthermore, we discuss the effects of DM conjugate altitude on the correction achievable by the MCAO system, and present the optimum DM conjugate altitudes.

  18. Molecules with linear pi-conjugated pathways between all substituents : Omniconjugation

    NARCIS (Netherlands)

    van der Veen, M.H.; Rispens, M.T; Jonkman, H.T.; Hummelen, J.C.

    In this paper, omniconjugation is introduced as a topological phenomenon in pi-conjugated systems. Omniconjugated molecules are defined by the fact that they provide direct and fully pi-conjugated pathways between all subdstituents attached to them. Surprisingly, until now such topologies have never

  19. Molecules with Linear π-Conjugated Pathways between All Substituents : Omniconjugation

    NARCIS (Netherlands)

    Veen, Marleen H. van der; Rispens, Minze T.; Jonkman, Harry T.; Hummelen, Jan C.

    2004-01-01

    In this paper, omniconjugation is introduced as a topological phenomenon in π-conjugated systems. Omniconjugated molecules are defined by the fact that they provide direct and fully π-conjugated pathways between all substituents attached to them. Surprisingly, until now such topologies have never

  20. Dynamical Approach to Multiequilibria Problems for Mixtures of Acids and Their Conjugated Bases

    Science.gov (United States)

    Glaser, Rainer E.; Delarosa, Marco A.; Salau, Ahmed Olasunkanmi; Chicone, Carmen

    2014-01-01

    Mathematical methods are described for the determination of steady-state concentrations of all species in multiequilibria systems consisting of several acids and their conjugated bases in aqueous solutions. The main example consists of a mixture of a diprotic acid H[subscript 2]A, a monoprotic acid HB, and their conjugate bases. The reaction…

  1. Cholesterol-conjugated supramolecular assemblies of low generations polyamidoamine dendrimers for enhanced EGFP plasmid DNA transfection

    Energy Technology Data Exchange (ETDEWEB)

    Golkar, Nasim; Samani, Soliman Mohammadi; Tamaddon, Ali Mohammad, E-mail: amtamadon@gmail.com [Shiraz University of Medical Sciences, Department of Pharmaceutics, School of Pharmacy (Iran, Islamic Republic of)

    2016-05-15

    Aimed to prepare an enhanced gene delivery system with low cytotoxicity and high transfection efficiency, various cholesterol-conjugated derivates of low generation polyamidoamine (PAMAM) dendrimers were prepared. The conjugates were characterized by TNBS assay, FTIR, and {sup 1}H-NMR spectroscopy. Self-assembly of the dendrimer conjugates (G1-Chol, G2-Chol, and G3-Chol) was investigated by pyrene assay. Following formation of the complexes between enhanced green fluorescence protein plasmid and the dendrimer conjugates at various N (primary amine)/P (phosphate) mole ratios, plasmid condensation, biologic stability, cytotoxicity, and protein expression were investigated. The conjugates self-assembled into micellar dispersions with the critical micelle concentration values (<50 µg/ml) depending on the dendrimer generation and cholesterol/amine mole ratio. Cholesterol conjugation resulted in higher resistance of the condensed plasmid DNA in a competition assay with heparin sulfate. Also, the transfection efficiency was determined higher for the cholesterol conjugates than unmodified dendrimers in HepG2 cells, showing the highest for G2-Chol at 40 % degree of cholesterol modification (G2-Chol{sub 40 %}) among various dendrimer generations. Interestingly, such conjugate showed a complete protection of plasmid against serum nucleases. Our results confirmed that the cholesterol conjugation to PAMAM dendrimers of low generations bearing little cytotoxicity improves their several physicochemical and biological characteristics required for an enhanced delivery of plasmid DNA into cells.

  2. Rhenium 188 labelling of peptide conjugates

    International Nuclear Information System (INIS)

    Melendez-Alafort, Laura

    2001-01-01

    Many human tumours express high levels, of somatostatin receptors. In order to make possible a radiotherapeutic treatment of this kind for tumour a series of somatostatin analogues that can tightly chelate beta emitting isotopes have been developed in recent years. The work carried out for this thesis has been aimed towards development of a new therapeutic radiopharmaceutical for treatment of somatostatin receptor positive tumours. The first chapters describe work with technetium-99m to establish the labelling and analytical conditions for a somatostatin analogue, [Tyr 3 ]-octreotide (TOC), as a precursor to undertaking labelling studies with the beta emitter rhenium-188. 6-Hydrazinopyridine-3-carboxylic acid (HYNIC) was conjugated to TOC and labelled with 99m using different coligands. Then the stability, receptor binding and biodistribution of each complex were assessed. 99m Tc-HYNIC-TOC using EDDA as coligand showed the best characteristics, and was superior for tumour imaging in humans than the commercially available 111 In-DTPA-octreotide. The conditions for labelling the HYNIC-TOC conjugate with 188 Re were then optimised using tricine as a co-ligand. A labelling yield of ∼80% was achieved. After purification however, the stability of the complex was low. The use of other coligand systems which had proved useful for 99m Tc labelling was explored, but yields were very poor. Other chelators such as diethylenetriamine pentaacetic acid (DTPA), dimercaptosuccinic acid (DMSA) and mercaptoacetyltriglycine (MAG 3 ) were studied as potential co-ligand agents to label the HYNIC-TOC conjugate with 188 Re but, again low yields of the labelled peptide complexes were achieved. A novel 188 Re-HYNIC complex was prepared in high yields using N-N-disubstituted dithiocarbamates as coligands. However to date, the specific activities achieved with this system are relatively low. The use of the [ 99m Tc(CO) 3 (H 2 O) 3 ] complex to label the HYNIC-TOC conjugate was investigated

  3. Development of surface-engineered PLGA nanoparticulate-delivery system of Tet1-conjugated nattokinase enzyme for inhibition of Aβ40 plaques in Alzheimer’s disease

    Science.gov (United States)

    Bhatt, Prakash Chandra; Verma, Amita; Al-Abbasi, Fahad A; Anwar, Firoz; Kumar, Vikas; Panda, Bibhu Prasad

    2017-01-01

    According to the World Health Organization, globally there are around 18 million patients suffering from Alzheimer’s disease (AD), and this number is expected to double by 2025. The pathophysiology of AD includes selective deposition of Aβ peptide in the mitochondria of cells, which inhibits uptake of glucose by neurons and key enzyme functions. Current drug treatments for AD are unable to rectify the underlying pathology of the disease; they only provide short-term symptomatic relief, so there is a need for the development of newer treatment regimes. The antiamyloid activity, antifibrinolytic activity, and antithrombotic activity of nattokinase holds potential for the treatment of AD. As nattokinase is a protein, its stability restricts its usage to a greater extent, but this limitation can be overcome by nanoencapsulation. In this work, we successfully synthesized polymeric nanoparticles of nattokinase and characterized its use by different techniques: transmission electron microscopy, scanning electron microscopy, DTS Nano, differential scanning calorimetry, Fourier-transform infrared spectroscopy, thioflavin T-binding assay, in vitro drug release, antifibrinolytic activity, and in vivo antiamyloid activity. As brain targeting of hydrophilic drugs is complicated due to the stringent nature of blood–brain barrier, in the current experimental study, we conjugated poly(lactic-co-glycolic acid) (PLGA)-encapsulated nattokinase with Tet1 peptide, which exhibits retrograde transportation properties because of its affinity to neurons. Our study suggests that PLGA-encapsulated nattokinase polymeric nanoparticles are able to downregulate amyloid aggregation and exhibit antifibrinolytic activity. The encapsulation of nattokinase in PLGA did not affect its enzyme activity, so the prepared nanoformulation containing nattokinase can be used as an effective drug treatment against AD. PMID:29263666

  4. Development of surface-engineered PLGA nanoparticulate-delivery system of Tet1-conjugated nattokinase enzyme for inhibition of Aβ40 plaques in Alzheimer's disease.

    Science.gov (United States)

    Bhatt, Prakash Chandra; Verma, Amita; Al-Abbasi, Fahad A; Anwar, Firoz; Kumar, Vikas; Panda, Bibhu Prasad

    2017-01-01

    According to the World Health Organization, globally there are around 18 million patients suffering from Alzheimer's disease (AD), and this number is expected to double by 2025. The pathophysiology of AD includes selective deposition of Aβ peptide in the mitochondria of cells, which inhibits uptake of glucose by neurons and key enzyme functions. Current drug treatments for AD are unable to rectify the underlying pathology of the disease; they only provide short-term symptomatic relief, so there is a need for the development of newer treatment regimes. The antiamyloid activity, antifibrinolytic activity, and antithrombotic activity of nattokinase holds potential for the treatment of AD. As nattokinase is a protein, its stability restricts its usage to a greater extent, but this limitation can be overcome by nanoencapsulation. In this work, we successfully synthesized polymeric nanoparticles of nattokinase and characterized its use by different techniques: transmission electron microscopy, scanning electron microscopy, DTS Nano, differential scanning calorimetry, Fourier-transform infrared spectroscopy, thioflavin T-binding assay, in vitro drug release, antifibrinolytic activity, and in vivo antiamyloid activity. As brain targeting of hydrophilic drugs is complicated due to the stringent nature of blood-brain barrier, in the current experimental study, we conjugated poly(lactic- co -glycolic acid) (PLGA)-encapsulated nattokinase with Tet1 peptide, which exhibits retrograde transportation properties because of its affinity to neurons. Our study suggests that PLGA-encapsulated nattokinase polymeric nanoparticles are able to downregulate amyloid aggregation and exhibit antifibrinolytic activity. The encapsulation of nattokinase in PLGA did not affect its enzyme activity, so the prepared nanoformulation containing nattokinase can be used as an effective drug treatment against AD.

  5. Quantitative clinical uptake measurements using conjugate counting

    International Nuclear Information System (INIS)

    Lathrop, K.A.; Bartlett, R.D.; Chen, C.T.; Chou, J.S.; Faulhaber, P.F.; Harper, P.V.; Stark, V.J.

    1986-01-01

    While the use of conjugate counting for determination of organ uptake in human subjects has been extensively described, in the present study the determination of the organ uptake of ortho-iodohippurate presented several opportunities for validation of the in vivo counting data. Ortho-iodohippurate is distributed in the extracellular space, is largely extracted on each pass through the kidneys, and is not significantly deiodinated in vivo. Thus, the kidney uptake rate should be proportional to the blood level, the appearance rate of activity in the bladder is equal to the disappearance rate from the kidneys, and direct measurement of activity in the urine after voiding provides an internal standard for imaging measurements of bladder activity. Since the activity levels in the kidneys, bladder, and remainder of the body changed fairly rapidly, especially in the first 20 to 30 minutes following injection, posterior images of the trunk including kidneys and bladder were obtained continuously using a gamma camera fitted with a diverging collimator for 30 minutes and then at intervals for several hours. Simultaneous conjugate counting determinations were made using a whole body scanning system previously described at these meetings. Imaging data corrected for decay and adjacent background were fitted by least squares methods to curves representing a sum of exponentials, and the curves were normalized to the conjugate uptake measurements. The uptake curves of the kidneys and bladder matched well with the direct measurements of the urinary excretion. Data were collected in 16 normal subjects, and the estimated absorbed dose was calculated for the kidneys, the bladder and the remainder of the body for seven radioisotopes of iodine. 4 references, 6 figures, 2 tables

  6. Experiments with conjugate gradient algorithms for homotopy curve tracking

    Science.gov (United States)

    Irani, Kashmira M.; Ribbens, Calvin J.; Watson, Layne T.; Kamat, Manohar P.; Walker, Homer F.

    1991-01-01

    There are algorithms for finding zeros or fixed points of nonlinear systems of equations that are globally convergent for almost all starting points, i.e., with probability one. The essence of all such algorithms is the construction of an appropriate homotopy map and then tracking some smooth curve in the zero set of this homotopy map. HOMPACK is a mathematical software package implementing globally convergent homotopy algorithms with three different techniques for tracking a homotopy zero curve, and has separate routines for dense and sparse Jacobian matrices. The HOMPACK algorithms for sparse Jacobian matrices use a preconditioned conjugate gradient algorithm for the computation of the kernel of the homotopy Jacobian matrix, a required linear algebra step for homotopy curve tracking. Here, variants of the conjugate gradient algorithm are implemented in the context of homotopy curve tracking and compared with Craig's preconditioned conjugate gradient method used in HOMPACK. The test problems used include actual large scale, sparse structural mechanics problems.

  7. ER Stress and Autophagic Perturbations Lead to Elevated Extracellular α-Synuclein in GBA-N370S Parkinson's iPSC-Derived Dopamine Neurons

    DEFF Research Database (Denmark)

    Fernandes, H. J. R.; Hartfield, E. M.; Christian Kjeldsen, Hans

    2016-01-01

    -derived neuronal culture medium, which was not associated with exosomes. Overall, ER stress, autophagic/lysosomal perturbations, and elevated extracellular α-synuclein likely represent critical early cellular phenotypes of PD, which might offer multiple therapeutic targets. © 2016 The Authors....

  8. Mild hypothermia protects hippocampal neurons against oxygen-glucose deprivation/reperfusion-induced injury by improving lysosomal function and autophagic flux.

    Science.gov (United States)

    Zhou, Tianen; Liang, Lian; Liang, Yanran; Yu, Tao; Zeng, Chaotao; Jiang, Longyuan

    2017-09-15

    Mild hypothermia has been proven to be useful to treat brain ischemia/reperfusion injury. However, the underlying mechanisms have not yet been fully elucidated. The present study was undertaken to determine whether mild hypothermia protects hippocampal neurons against oxygen-glucose deprivation/reperfusion(OGD/R)-induced injury via improving lysosomal function and autophagic flux. The results showed that OGD/R induced the occurrence of autophagy, while the acidic environment inside the lysosomes was altered. The autophagic flux assay with RFP-GFP tf-LC3 was impeded in hippocampal neurons after OGD/R. Mild hypothermia recovered the lysosomal acidic fluorescence and the lysosomal marker protein expression of LAMP2, which decreased after OGD/R.Furthermore, we found that mild hypothermia up-regulated autophagic flux and promoted the fusion of autophagosomes and lysosomes in hippocampal neurons following OGD/R injury, but could be reversed by treatment with chloroquine, which acts as a lysosome inhibitor. We also found that mild hypothermia improved mitochondrial autophagy in hippocampal neurons following OGD/R injury. Finally,we found that chloroquine blocked the protective effects of mild hypothermia against OGD/R-induced cell death and injury. Taken together, the present study indicates that mild hypothermia protects hippocampal neurons against OGD/R-induced injury by improving lysosomal function and autophagic flux. Copyright © 2017. Published by Elsevier Inc.

  9. The extended regulatory networks of SXT/R391 integrative and conjugative elements and IncA/C conjugative plasmids.

    Science.gov (United States)

    Poulin-Laprade, Dominic; Carraro, Nicolas; Burrus, Vincent

    2015-01-01

    Nowadays, healthcare systems are challenged by a major worldwide drug resistance crisis caused by the massive and rapid dissemination of antibiotic resistance genes and associated emergence of multidrug resistant pathogenic bacteria, in both clinical and environmental settings. Conjugation is the main driving force of gene transfer among microorganisms. This mechanism of horizontal gene transfer mediates the translocation of large DNA fragments between two bacterial cells in direct contact. Integrative and conjugative elements (ICEs) of the SXT/R391 family (SRIs) and IncA/C conjugative plasmids (ACPs) are responsible for the dissemination of a broad spectrum of antibiotic resistance genes among diverse species of Enterobacteriaceae and Vibrionaceae. The biology, diversity, prevalence and distribution of these two families of conjugative elements have been the subject of extensive studies for the past 15 years. Recently, the transcriptional regulators that govern their dissemination through the expression of ICE- or plasmid-encoded transfer genes have been described. Unrelated repressors control the activation of conjugation by preventing the expression of two related master activator complexes in both types of elements, i.e., SetCD in SXT/R391 ICEs and AcaCD in IncA/C plasmids. Finally, in addition to activating ICE- or plasmid-borne genes, these master activators have been shown to specifically activate phylogenetically unrelated mobilizable genomic islands (MGIs) that also disseminate antibiotic resistance genes and other adaptive traits among a plethora of pathogens such as Vibrio cholerae and Salmonella enterica.

  10. The extended regulatory networks of SXT/R391 integrative and conjugative elements and IncA/C conjugative plasmids.

    Directory of Open Access Journals (Sweden)

    Dominic ePoulin-Laprade

    2015-08-01

    Full Text Available Nowadays, healthcare systems are challenged by a major worldwide drug resistance crisis caused by the massive and rapid dissemination of antibiotic resistance genes and associated emergence of multidrug resistant pathogenic bacteria, in both clinical and environmental settings. Conjugation is the main driving force of gene transfer among microorganisms. This mechanism of horizontal gene transfer mediates the translocation of large DNA fragments between two bacterial cells in direct contact. Integrative and conjugative elements (ICEs of the SXT/R391 family (SRIs and IncA/C conjugative plasmids (ACPs are responsible for the dissemination of a broad spectrum of antibiotic resistance genes among diverse species of Enterobacteriaceae and Vibrionaceae. The biology, diversity, prevalence and distribution of these two families of conjugative elements have been the subject of extensive studies for the past 15 years. Recently, the transcriptional regulators that govern their dissemination through the expression of ICE- or plasmid-encoded transfer genes have been described. Unrelated repressors control the activation of conjugation by preventing the expression of two related master activator complexes in both types of elements, i.e. SetCD in SXT/R391 ICEs and AcaCD in IncA/C plasmids. Finally, in addition to activating ICE- or plasmid-borne genes, these master activators have been shown to specifically activate phylogenetically unrelated mobilizable genomic islands (MGIs that also disseminate antibiotic resistance genes and other adaptive traits among a plethora of pathogens such as Vibrio cholerae and Salmonella enterica.

  11. Human Intestinal Cells Modulate Conjugational Transfer of Multidrug Resistance Plasmids between Clinical Escherichia coli Isolates

    DEFF Research Database (Denmark)

    Machado, Ana Manuel; Sommer, Morten

    2014-01-01

    Bacterial conjugation in the human gut microbiota is believed to play a major role in the dissemination of antibiotic resistance genes and virulence plasmids. However, the modulation of bacterial conjugation by the human host remains poorly understood and there is a need for controlled systems...... to study this process. We established an in vitro co-culture system to study the interaction between human intestinal cells and bacteria. We show that the conjugation efficiency of a plasmid encoding an extended spectrum beta-lactamase is reduced when clinical isolates of Escherichia coli are co...... of the intestinal cells exposed to bacteria leading to a two-fold reduction in conjugation efficiency. These results show that human gut epithelial cells can modulate bacterial conjugation and may have relevance to gene exchange in the gut....

  12. A fast, preconditioned conjugate gradient Toeplitz solver

    Science.gov (United States)

    Pan, Victor; Schrieber, Robert

    1989-01-01

    A simple factorization is given of an arbitrary hermitian, positive definite matrix in which the factors are well-conditioned, hermitian, and positive definite. In fact, given knowledge of the extreme eigenvalues of the original matrix A, an optimal improvement can be achieved, making the condition numbers of each of the two factors equal to the square root of the condition number of A. This technique is to applied to the solution of hermitian, positive definite Toeplitz systems. Large linear systems with hermitian, positive definite Toeplitz matrices arise in some signal processing applications. A stable fast algorithm is given for solving these systems that is based on the preconditioned conjugate gradient method. The algorithm exploits Toeplitz structure to reduce the cost of an iteration to O(n log n) by applying the fast Fourier Transform to compute matrix-vector products. Matrix factorization is used as a preconditioner.

  13. Development of surface-engineered PLGA nanoparticulate-delivery system of Tet-1-conjugated nattokinase enzyme for inhibition of Aβ40 plaques in Alzheimer’s disease

    Directory of Open Access Journals (Sweden)

    Bhatt PC

    2017-12-01

    release, antifibrinolytic activity, and in vivo antiamyloid activity. As brain targeting of hydrophilic drugs is complicated due to the stringent nature of blood–brain barrier, in the current experimental study, we conjugated poly(lactic-co-glycolic acid (PLGA-encapsulated nattokinase with Tet1 peptide, which exhibits retrograde transportation properties because of its affinity to neurons. Our study suggests that PLGA-encapsulated nattokinase polymeric nanoparticles are able to downregulate amyloid aggregation and exhibit antifibrinolytic activity. The encapsulation of nattokinase in PLGA did not affect its enzyme activity, so the prepared nanoformulation containing nattokinase can be used as an effective drug treatment against AD. Keywords: nattokinase, PLGA, Aβ40, Alzheimer’s disease, surface modification, TEM, Tet1 peptide 

  14. Morphological Priming by Itself: A Study of Portuguese Conjugations

    Science.gov (United States)

    Verissimo, Joao; Clahsen, Harald

    2009-01-01

    Does the language processing system make use of abstract grammatical categories and representations that are not directly visible from the surface form of a linguistic expression? This study examines stem-formation processes and conjugation classes, a case of "pure" morphology that provides insight into the role of grammatical structure in…

  15. QM/MM-MD simulations of conjugated polyelectrolytes

    DEFF Research Database (Denmark)

    Sjöqvist, Jonas; Linares, Mathieu; Mikkelsen, Kurt Valentin

    2014-01-01

    A methodological development is reported for the study of luminescence properties of conjugated polyelectrolytes, encompassing systems in which dihedral rotational barriers are easily overcome at room temperature. The components of the model include (i) a molecular mechanics (MM) force field desc...

  16. Self-assembly behaviour of conjugated terthiophene surfactants in water

    NARCIS (Netherlands)

    van Rijn, Patrick; Janeliunas, Dainius; Brizard, Aurelie M.; Stuart, Marc C. A.; Koper, Ger J. M.; Eelkema, Rienk; van Esch, Jan H.

    2011-01-01

    Conjugated self-assembled systems in water are of great interest because of their potential application in biocompatible supramolecular electronics, but so far their supramolecular chemistry remains almost unexplored. Here we present amphiphilic terthiophenes as a general self-assembling platform

  17. Bio-degradable highly fluorescent conjugated polymer nanoparticles for bio-medical imaging applications.

    Science.gov (United States)

    Repenko, Tatjana; Rix, Anne; Ludwanowski, Simon; Go, Dennis; Kiessling, Fabian; Lederle, Wiltrud; Kuehne, Alexander J C

    2017-09-07

    Conjugated polymer nanoparticles exhibit strong fluorescence and have been applied for biological fluorescence imaging in cell culture and in small animals. However, conjugated polymer particles are hydrophobic and often chemically inert materials with diameters ranging from below 50 nm to several microns. As such, conjugated polymer nanoparticles cannot be excreted through the renal system. This drawback has prevented their application for clinical bio-medical imaging. Here, we present fully conjugated polymer nanoparticles based on imidazole units. These nanoparticles can be bio-degraded by activated macrophages. Reactive oxygen species induce scission of the conjugated polymer backbone at the imidazole unit, leading to complete decomposition of the particles into soluble low molecular weight fragments. Furthermore, the nanoparticles can be surface functionalized for directed targeting. The approach opens a wide range of opportunities for conjugated polymer particles in the fields of medical imaging, drug-delivery, and theranostics.Conjugated polymer nanoparticles have been applied for biological fluorescence imaging in cell culture and in small animals, but cannot readily be excreted through the renal system. Here the authors show fully conjugated polymer nanoparticles based on imidazole units that can be bio-degraded by activated macrophages.

  18. MicroRNA-20a inhibits autophagic process by targeting ATG7 and ATG16L1 and favors mycobacterial survival in macrophage cells.

    Directory of Open Access Journals (Sweden)

    Le Guo

    2016-10-01

    Full Text Available Autophagy plays important roles in the host immune response against mycobacterial infection. Mycobacterium tuberculosis (M. tuberculosis can live in macrophages owing to its ability to evade attacks by regulating autophagic response. MicroRNAs (miRNAs are small noncoding, endogenously encoded RNA which plays critical roles in precise regulation of macrophage functions. Whether miRNAs specifically influence the activation of macrophage autophagy during M. tuberculosis infection are largely unknown. In this study, we demonstrate that BCG infection of macrophages resulted in enhanced expression of miRNA-20a, which inhibits autophagic process by targeting ATG7 and ATG16L1 and promotes BCG survival in macrophages. Forced overexpression of miR-20a decreased the expression levels of LC3-II and the number of LC3 puncta in macrophages, and promoted BCG survival in macrophages, while transfection with miR-20a inhibitor had the opposite effect. Moreover, the inhibitory effect of miR-20a on autophagy was further confimed by transmission electron microscopy (TEM analysis. Quantification of autophagosomes per cellular cross-section revealed a significant reduction upon transfection with miR-20a mimic, but transfection with miR-20a inhibitor increased the number of autophagosomes per cellular cross-section. Moreover, silencing of ATG7 significantly inhibited autophagic response, and transfection with ATG7 siRNA plus miR-20a mimic could further decrease autophagic response. Collectively, our data reveal that miR-20a inhibits autophagic response and promotes BCG survival in macrophages by targeting ATG7 and ATG16L1, which may have implications for a better understanding of pathogenesis of M. tuberculosis infection.

  19. microRNA-20a Inhibits Autophagic Process by Targeting ATG7 and ATG16L1 and Favors Mycobacterial Survival in Macrophage Cells.

    Science.gov (United States)

    Guo, Le; Zhao, Jin; Qu, Yuliang; Yin, Runting; Gao, Qian; Ding, Shuqin; Zhang, Ying; Wei, Jun; Xu, Guangxian

    2016-01-01

    Autophagy plays important roles in the host immune response against mycobacterial infection. Mycobacterium tuberculosis ( M. tuberculosis ) can live in macrophages owing to its ability to evade attacks by regulating autophagic response. MicroRNAs (miRNAs) are small noncoding, endogenously encoded RNA which plays critical roles in precise regulation of macrophage functions. Whether miRNAs specifically influence the activation of macrophage autophagy during M. tuberculosis infection are largely unknown. In this study, we demonstrate that BCG infection of macrophages resulted in enhanced expression of miRNA-20a, which inhibits autophagic process by targeting ATG7 and ATG16L1 and promotes BCG survival in macrophages. Forced overexpression of miR-20a decreased the expression levels of LC3-II and the number of LC3 puncta in macrophages, and promoted BCG survival in macrophages, while transfection with miR-20a inhibitor had the opposite effect. Moreover, the inhibitory effect of miR-20a on autophagy was further confirmed by transmission electron microscopy (TEM) analysis. Quantification of autophagosomes per cellular cross-section revealed a significant reduction upon transfection with miR-20a mimic, but transfection with miR-20a inhibitor increased the number of autophagosomes per cellular cross-section. Moreover, silencing of ATG7 significantly inhibited autophagic response, and transfection with ATG7 siRNA plus miR-20a mimic could further decrease autophagic response. Collectively, our data reveal that miR-20a inhibits autophagic response and promotes BCG survival in macrophages by targeting ATG7 and ATG16L1, which may have implications for a better understanding of pathogenesis of M. tuberculosis infection.

  20. In vivo effect of an antilipolytic drug (3,5'-dimethylpyrazole) on autophagic proteolysis and autophagy-related gene expression in rat liver

    International Nuclear Information System (INIS)

    Donati, Alessio; Ventruti, Annamaria; Cavallini, Gabriella; Masini, Matilde; Vittorini, Simona; Chantret, Isabelle; Codogno, Patrice; Bergamini, Ettore

    2008-01-01

    Autophagy is an intracellular pathway induced by starvation, inhibited by nutrients, that is responsible for degradation of long-lived proteins and altered cell organelles. This process is involved in cell maintenance could be induced by antilipolytic drugs and may have anti-aging effects [A. Donati, The involvement of macroautophagy in aging and anti-aging interventions, Mol. Aspects Med. 27 (2006) 455-470]. We analyzed the effect of an intraperitoneal injection of an antilipolytic agent (3,5'-dimethylpyrazole, DMP, 12 mg/kg b.w.), that mimics nutrient shortage on autophagy and expression of autophagic genes in the liver of male 3-month-old Sprague-Dawley albino rats. Autophagy was evaluated by observing electron micrographs of the liver autophagosomal compartment and by monitoring protein degradation assessed by the release of valine into the bloodstream. LC3 gene expression, whose product is one of the best known markers of autophagy, was also monitored. As expected, DMP decreased the plasma levels of free fatty acids, glucose, and insulin and increased autophagic vacuoles and proteolysis. DMP treatment caused an increase in the expression of the LC3 gene although this occurred later than the induction of authophagic proteolysis caused by DMP. Glucose treatment rescued the effects caused by DMP on glucose and insulin plasma levels and negatively affected the rate of autophagic proteolysis, but did not suppress the positive regulatory effect on LC3 mRNA levels. In conclusion, antilipolytic drugs may induce both autophagic proteolysis and higher expression of an autophagy-related gene and the effect on autophagy gene expression might not be secondary to the stimulation of autophagic proteolysis

  1. Antibody-Conjugated Nanoparticles for Biomedical Applications

    Directory of Open Access Journals (Sweden)

    Manuel Arruebo

    2009-01-01

    Full Text Available Nanoscience and Nanotechnology have found their way into the fields of Biotechnology and Medicine. Nanoparticles by themselves offer specific physicochemical properties that they do not exhibit in bulk form, where materials show constant physical properties regardless of size. Antibodies are nanosize biological products that are part of the specific immune system. In addition to their own properties as pathogens or toxin neutralizers, as well as in the recruitment of immune elements (complement, improving phagocytosis, cytotoxicity antibody dependent by natural killer cells, etc., they could carry several elements (toxins, drugs, fluorochroms, or even nanoparticles, etc. and be used in several diagnostic procedures, or even in therapy to destroy a specific target. The conjugation of antibodies to nanoparticles can generate a product that combines the properties of both. For example, they can combine the small size of nanoparticles and their special thermal, imaging, drug carrier, or magnetic characteristics with the abilities of antibodies, such as specific and selective recognition. The hybrid product will show versatility and specificity. In this review, we analyse both antibodies and nanoparticles, focusing especially on the recent developments for antibody-conjugated nanoparticles, offering the researcher an overview of the different applications and possibilities of these hybrid carriers.

  2. Prospective Preliminary In Vitro Investigation of a Magnetic Iron Oxide Nanoparticle Conjugated with Ligand CD80 and VEGF Antibody As a Targeted Drug Delivery System for the Induction of Cell Death in Rodent Osteosarcoma Cells

    Directory of Open Access Journals (Sweden)

    Anne Marie Kay Kovach

    2016-10-01

    Full Text Available Target drug deliveries using nanotechnology are a novel consideration in the treatment of cancer. We present herein an in vitro mouse model for the preliminary investigation of the efficacy of an iron oxide nanoparticle complex conjugated to vascular endothelial growth factor (VEGF antibody and ligand cluster of differentiation 80 (CD80 for the purpose of eventual translational applications in the treatment of human osteosarcoma (OSA. The 35 nm diameter iron oxide magnetic nanoparticles are functionalized with an n-hydroxysuccinimide biocompatible coating and are conjugated on the surface to proteins VEGF antibody and ligand CD80. Combined, these proteins have the ability to target OSA cells and induce apoptosis. The proposed system was tested on a cancerous rodent osteoblast cell line (ATCCTMNPO CRL-2836 at four different concentrations (0.1, 1.0, 10.0, and 100.0 μg/mL of ligand CD80 alone, VEGF antibody alone, and a combination thereof (CD80+VEGF. Systems were implemented every 24 h over different sequential treatment timelines: 24, 48, and 72 h, to find the optimal protein concentration required for a reduction in cell proliferation. Results demonstrated that a combination of ligand CD80 and VEGF antibody was consistently most effective at reducing aberrant osteoblastic proliferation for both the 24- and 72-h timelines. At 48 h, however, an increase in cell proliferation was documented for the 0.1 and 1 μg/mL groups. For the 24- and 72-h tests, concentrations of 1.0 μg/mL of CD80+VEGF and 0.1 μg/mL of VEGF antibody were most effective. Concentrations of 10.0 and 100.0 μg/mL of CD80+VEGF reduced cell proliferation, but not as remarkably as the 1.0 μg/mL concentration. In addition, cell proliferation data showed that multiple treatments (72-h test induced cell death in the osteoblasts better than a single treatment. Future targeted drug delivery system research includes trials in OSA cell lines from greater phylum

  3. Fusobacterium nucleatum-Induced Impairment of Autophagic Flux Enhances the Expression of Proinflammatory Cytokines via ROS in Caco-2 Cells.

    Directory of Open Access Journals (Sweden)

    Bin Tang

    Full Text Available Fusobacterium nucleatum (F. nucleatum plays a critical role in gastrointestinal inflammation. However, the exact mechanism by which F. nucleatum contributes to inflammation is unclear. In the present study, it was revealed that F. nucleatum could induce the production of proinflammatory cytokines (IL-8, IL-1β and TNF-α and reactive oxygen species (ROS in Caco-2 colorectal adenocarcinoma cells. Furthermore, ROS scavengers (NAC or Tiron could decrease the production of proinflammatory cytokines during F. nucleatum infection. In addition, we observed that autophagy is impaired in Caco-2 cells after F. nucleatum infection. The production of proinflammatory cytokines and ROS induced by F. nucleatum was enhanced with either autophagy pharmacologic inhibitors (3-methyladenine, bafilomycin A1 or RNA interference in essential autophagy genes (ATG5 or ATG12 in Caco-2 cells. Taken together, these results indicate that F. nucleatum-induced impairment of autophagic flux enhances the expression of proinflammatory cytokines via ROS in Caco-2 Cells.

  4. Oxygen-Glucose-Deprivation/Reoxygenation-Induced Autophagic Cell Death Depends on JNK-Mediated Phosphorylation of Bcl-2

    Directory of Open Access Journals (Sweden)

    Jin Fan

    2016-03-01

    Full Text Available Background/Aims: The purpose of this study was to investigate the role of autophagy in oxygen-glucose-deprivation/reoxygenation (OGD/R injury in rat neurons. Methods and results: Cortical neurons were isolated from Sprague-Dawley rats and identified by immunofluorescence. The cortical neurons were randomly assigned to one of four groups: control group (I, experimental group (OGD/R group, II, JNK inhibitor pretreatment group (III and JNK inhibitor pretreatment + OGD/R group (IV. Neuronal cell viability significantly decreased after 6h and 12h of reoxygenation in Group IV (P P Conclusion: The regulation of the JNK/Bcl-2/Beclin-1 signaling pathway may be one of the mechanisms underlying the OGD/R-induced autophagic cell death of neurons.

  5. In Vivo Evidence for Lysosome Depletion and Impaired Autophagic Clearance in Hereditary Spastic Paraplegia Type SPG11.

    Directory of Open Access Journals (Sweden)

    Rita-Eva Varga

    2015-08-01

    Full Text Available Hereditary spastic paraplegia (HSP is characterized by a dying back degeneration of corticospinal axons which leads to progressive weakness and spasticity of the legs. SPG11 is the most common autosomal-recessive form of HSPs and is caused by mutations in SPG11. A recent in vitro study suggested that Spatacsin, the respective gene product, is needed for the recycling of lysosomes from autolysosomes, a process known as autophagic lysosome reformation. The relevance of this observation for hereditary spastic paraplegia, however, has remained unclear. Here, we report that disruption of Spatacsin in mice indeed causes hereditary spastic paraplegia-like phenotypes with loss of cortical neurons and Purkinje cells. Degenerating neurons accumulate autofluorescent material, which stains for the lysosomal protein Lamp1 and for p62, a marker of substrate destined to be degraded by autophagy, and hence appears to be related to autolysosomes. Supporting a more generalized defect of autophagy, levels of lipidated LC3 are increased in Spatacsin knockout mouse embryonic fibrobasts (MEFs. Though distinct parameters of lysosomal function like processing of cathepsin D and lysosomal pH are preserved, lysosome numbers are reduced in knockout MEFs and the recovery of lysosomes during sustained starvation impaired consistent with a defect of autophagic lysosome reformation. Because lysosomes are reduced in cortical neurons and Purkinje cells in vivo, we propose that the decreased number of lysosomes available for fusion with autophagosomes impairs autolysosomal clearance, results in the accumulation of undegraded material and finally causes death of particularly sensitive neurons like cortical motoneurons and Purkinje cells in knockout mice.

  6. HEPES activates a MiT/TFE-dependent lysosomal-autophagic gene network in cultured cells: A call for caution.

    Science.gov (United States)

    Tol, Marc J; van der Lienden, Martijn J C; Gabriel, Tanit L; Hagen, Jacob J; Scheij, Saskia; Veenendaal, Tineke; Klumperman, Judith; Donker-Koopman, Wilma E; Verhoeven, Arthur J; Overkleeft, Hermen; Aerts, Johannes M; Argmann, Carmen A; van Eijk, Marco

    2018-01-01

    In recent years, the lysosome has emerged as a highly dynamic, transcriptionally regulated organelle that is integral to nutrient-sensing and metabolic rewiring. This is coordinated by a lysosome-to-nucleus signaling nexus in which MTORC1 controls the subcellular distribution of the microphthalmia-transcription factor E (MiT/TFE) family of "master lysosomal regulators". Yet, despite the importance of the lysosome in cellular metabolism, the impact of traditional in vitro culture media on lysosomal dynamics and/or MiT/TFE localization has not been fully appreciated. Here, we identify HEPES, a chemical buffering agent that is broadly applied in cell culture, as a potent inducer of lysosome biogenesis. Supplementation of HEPES to cell growth media is sufficient to decouple the MiT/TFE family members-TFEB, TFE3 and MITF-from regulatory mechanisms that control their cytosolic retention. Increased MiT/TFE nuclear import in turn drives the expression of a global network of lysosomal-autophagic and innate host-immune response genes, altering lysosomal dynamics, proteolytic capacity, autophagic flux, and inflammatory signaling. In addition, siRNA-mediated MiT/TFE knockdown effectively blunted HEPES-induced lysosome biogenesis and gene expression profiles. Mechanistically, we show that MiT/TFE activation in response to HEPES requires its macropinocytic ingestion and aberrant lysosomal storage/pH, but is independent of MTORC1 signaling. Altogether, our data underscore the cautionary use of chemical buffering agents in cell culture media due to their potentially confounding effects on experimental results.

  7. Paraquat, but not maneb, induces synucleinopathy and tauopathy in striata of mice through inhibition of proteasomal and autophagic pathways.

    Directory of Open Access Journals (Sweden)

    Jonathan Wills

    Full Text Available SNCA and MAPT genes and environmental factors are important risk factors of Parkinson's disease [PD], the second-most common neurodegenerative disease. The agrichemicals maneb and paraquat selectively target dopaminergic neurons, leading to parkinsonism, through ill-defined mechanisms. In the current studies we have analyzed the ability of maneb and paraquat, separately and together, to induce synucleinopathy and tauopathy in wild type mice. Maneb was ineffective in increasing α-synuclein [α-Syn] or p-Tau levels. By contrast, paraquat treatment of mice resulted in robust accumulation of α-Syn and hyperphosphorylation of Tau in striata, through activation of p-GSK-3β, a major Tau kinase. Co-treatment with maneb did not enhance the effects of paraquat. Increased hyperacetylation of α-tubulin was observed in paraquat-treated mice, suggesting cytoskeleton remodeling. Paraquat, but not maneb, inhibited soluble proteasomal activity on a peptide substrate but this was not associated with a decreased expression of 26S proteasome subunits. Both paraquat and maneb treatments increased levels of the autophagy inhibitor, mammalian target of rapamycin, mTOR, suggesting impaired axonal autophagy, despite increases in certain autophagic proteins, such as beclin 1 and Agt12. Autophagic flux was also impaired, as ratios of LC3 II to LC3 I were reduced in treated animals. Increased mTOR was also observed in postmortem human PD striata, where there was a reduction in the LC3 II to LC3 I ratio. Heat shock proteins were either increased or unchanged upon paraquat-treatment suggesting that chaperone-mediated autophagy is not hampered by the agrichemicals. These studies provide novel insight into the mechanisms of action of these agrichemicals, which indicate that paraquat is much more toxic than maneb, via its inhibitory effects on proteasomes and autophagy, which lead to accumulation of α-Syn and p-Tau.

  8. Andrographolide alleviates imiquimod-induced psoriasis in mice via inducing autophagic proteolysis of MyD88.

    Science.gov (United States)

    Shao, Fenli; Tan, Tao; Tan, Yang; Sun, Yang; Wu, Xingxin; Xu, Qiang

    2016-09-01

    Psoriasis is a chronic inflammatory skin disease with excessive activation of toll-like receptors (TLRs), which play important roles in developing psoriasis. Targeting TLR signaling remains a challenge for treating psoriasis. Here, we found that andrographolide (Andro), a small-molecule natural product, alleviated imiquimod- but not interleukin 23 (IL-23)-induced psoriasis in mice with reducing expressions of IL-23 and IL-1β in the skin. The improvement in imiquimod-induced psoriasis by Andro was not observed in microtubule-associated protein 1 light chain 3 beta (MAP1LC3B) knockout mice. Furthermore, Andro inhibited mRNA expressions of IL-23, IL-6 and IL-1β but not CD80 and CD86 in bone-marrow derived dendritic cells (BMDCs) treated with lipopolysaccharide (LPS) in a MAP1LC3B-dependent manner. In addition, Andro inhibited imiquimod-induced mRNA expressions of IL-23, IL-6, IL-1β, CD80 and CD86 in BMDCs from mice. Interestingly, Andro induced a degradation of myeloid differentiation factor 88 (MyD88) and blocked the recruitment of TNF receptor-associated factor 6 (TRAF6) to MyD88 upon LPS stimulation in BMDCs from mice. Blockade of autophagic proteolysis using NH4Cl or MAP1LC3B(-/-) BMDCs abolished the Andro-induced MyD88 degradation. In conclusion, Andro controls activation of MyD88-dependent cytokines and alleviates psoriasis in mice via inducing autophagic proteolysis of MyD88, which could be a novel strategy to treat psoriasis. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. SET overexpression in HEK293 cells regulates mitochondrial uncoupling proteins levels within a mitochondrial fission/reduced autophagic flux scenario

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Luciana O.; Goto, Renata N. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Neto, Marinaldo P.C. [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Sousa, Lucas O. [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Curti, Carlos [Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil); Leopoldino, Andréia M., E-mail: andreiaml@usp.br [Department of Clinical Analyses, Toxicology and Food Sciences, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil)

    2015-03-06

    We hypothesized that SET, a protein accumulated in some cancer types and Alzheimer disease, is involved in cell death through mitochondrial mechanisms. We addressed the mRNA and protein levels of the mitochondrial uncoupling proteins UCP1, UCP2 and UCP3 (S and L isoforms) by quantitative real-time PCR and immunofluorescence as well as other mitochondrial involvements, in HEK293 cells overexpressing the SET protein (HEK293/SET), either in the presence or absence of oxidative stress induced by the pro-oxidant t-butyl hydroperoxide (t-BHP). SET overexpression in HEK293 cells decreased UCP1 and increased UCP2 and UCP3 (S/L) mRNA and protein levels, whilst also preventing lipid peroxidation and decreasing the content of cellular ATP. SET overexpression also (i) decreased the area of mitochondria and increased the number of organelles and lysosomes, (ii) increased mitochondrial fission, as demonstrated by increased FIS1 mRNA and FIS-1 protein levels, an apparent accumulation of DRP-1 protein, and an increase in the VDAC protein level, and (iii) reduced autophagic flux, as demonstrated by a decrease in LC3B lipidation (LC3B-II) in the presence of chloroquine. Therefore, SET overexpression in HEK293 cells promotes mitochondrial fission and reduces autophagic flux in apparent association with up-regulation of UCP2 and UCP3; this implies a potential involvement in cellular processes that are deregulated such as in Alzheimer's disease and cancer. - Highlights: • SET, UCPs and autophagy prevention are correlated. • SET action has mitochondrial involvement. • UCP2/3 may reduce ROS and prevent autophagy. • SET protects cell from ROS via UCP2/3.

  10. 17-AAG post-treatment ameliorates memory impairment and hippocampal CA1 neuronal autophagic death induced by transient global cerebral ischemia.

    Science.gov (United States)

    Li, Jianxiong; Yang, Fei; Guo, Jia; Zhang, Rongrong; Xing, Xiangfeng; Qin, Xinyue

    2015-06-12

    Neuro-inflammation plays an important role in global cerebral ischemia (GCI). The 72-kDa heat shock protein (Hsp70) has been reported to be involved in the inflammatory response of many central nervous system diseases. Preclinical findings implicate that 17-allylamino-demethoxygeldanamycin (17-AAG), an anticancer drug in clinical, provide neuroprotection actions in a rat model of traumatic brain injury, and the beneficial effects of 17-AAG were specifically due to up-regulation of Hsp70. However, no experiments have tested whether 17-AAG has beneficial or harmful effects in the setting of GCI. The present study was designed to determine the hypothesis that administration of 17-AAG could attenuate cerebral infarction and improve neuronal survival, thereby ameliorating memory impairment in a rat model of GCI. Furthermore, to test whether any neuroprotective effect of 17-AAG was associated with inflammatory response and neuronal autophagy, we examined the expression of multiplex inflammatory cytokine levels as well as autophagy-associate protein in hippocampal CA1 of rat brain. Our results showed that post-GCI administration of 17-AAG significantly protected rats against GCI induced brain injury, and 17-AAG is also an effective antagonist of the inflammatory response and thereby ameliorates hippocampal CA1 neuronal autophagic death. We therefore believe that the present study provides novel clues in understanding the mechanisms by which 17-AAG exerts its neuroprotective activity in GCI. All data reveal that 17-AAG might be a potential neuroprotective agent for ischemic stroke. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Comparison of preconditioned generalized conjugate gradient methods to two-dimensional neutron and photon transport equation

    International Nuclear Information System (INIS)

    Chen, G.S.

    1997-01-01

    We apply and compare the preconditioned generalized conjugate gradient methods to solve the linear system equation that arises in the two-dimensional neutron and photon transport equation in this paper. Several subroutines are developed on the basis of preconditioned generalized conjugate gradient methods for time-independent, two-dimensional neutron and photon transport equation in the transport theory. These generalized conjugate gradient methods are used. TFQMR (transpose free quasi-minimal residual algorithm), CGS (conjuage gradient square algorithm), Bi-CGSTAB (bi-conjugate gradient stabilized algorithm) and QMRCGSTAB (quasi-minimal residual variant of bi-conjugate gradient stabilized algorithm). These sub-routines are connected to computer program DORT. Several problems are tested on a personal computer with Intel Pentium CPU. (author)

  12. Conjugate Gradient like methods and their application to fixed source neutron diffusion problems

    International Nuclear Information System (INIS)

    Suetomi, Eiichi; Sekimoto, Hiroshi

    1989-01-01

    This paper presents a number of fast iterative methods for solving systems of linear equations appearing in fixed source problems for neutron diffusion. We employed the conjugate gradient and conjugate residual methods. In order to accelerate the conjugate residual method, we proposed the conjugate residual squared method by transforming the residual polynomial of the conjugate residual method. Since the convergence of these methods depends on the spectrum of coefficient matrix, we employed the incomplete Choleski (IC) factorization and the modified IC (MIC) factorization as preconditioners. These methods were applied to some neutron diffusion problems and compared with the successive overrelaxation (SOR) method. The results of these numerical experiments showed superior convergence characteristics of the conjugate gradient like method with MIC factorization to the SOR method, especially for a problem involving void region. The CPU time of the MICCG, MICCR and MICCRS methods showed no great difference. In order to vectorize the conjugate gradient like methods based on (M)IC factorization, the hyperplane method was used and implemented on the vector computers, the HITAC S-820/80 and ETA10-E (one processor mode). Significant decrease of the CPU times was observed on the S-820/80. Since the scaled conjugate gradient (SCG) method can be vectorized with no manipulation, it was also compared with the above methods. It turned out the SCG method was the fastest with respect to the CPU times on the ETA10-E. These results suggest that one should implement suitable algorithm for different vector computers. (author)

  13. Conjugated Polymers for Energy Production

    DEFF Research Database (Denmark)

    Livi, Francesco

    This dissertation is aimed at developing materials for flexible, large area, ITO-free polymer solar cells (PSCs) fully printed under ambient conditions. A large screening of conjugated polymers, both novel and well-known materials, has been carried out in order to find suitable candidates...... polymerization method for industrial production of polymers. Several DArP protocols have been employed for the synthesis of PPDTBT leading to polymers with high structural regularity and photovoltaic performances comparable with the same materials synthesized via Stille cross-coupling polymerization...

  14. Novel ?-cyclodextrin?eosin conjugates

    OpenAIRE

    Benkovics, G?bor; Afonso, Damien; Darcsi, Andr?s; B?ni, Szabolcs; Conoci, Sabrina; Fenyvesi, ?va; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy an...

  15. Test of charge conjugation invariance

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.; Prakhov, S.; Gaardestig, A.; Clajus, M.; Marusic, A.; McDonald, S.; Phaisangittisakul, N.; Price, J.W.; Starostin, A.; Tippens, W.B.; Allgower, C.E.; Spinka, H.; Bekrenev, V.; Koulbardis, A.; Kozlenko, N.; Kruglov, S.; Lopatin, I.; Briscoe, W.J.; Shafi, A.; Comfort, J.R.

    2005-01-01

    We report on the first determination of upper limits on the branching ratio (BR) of η decay to π 0 π 0 γ and to π 0 π 0 π 0 γ. Both decay modes are strictly forbidden by charge conjugation (C) invariance. Using the Crystal Ball multiphoton detector, we obtained BR(η→π 0 π 0 γ) -4 at the 90% confidence level, in support of C invariance of isoscalar electromagnetic interactions of the light quarks. We have also measured BR(η→π 0 π 0 π 0 γ) -5 at the 90% confidence level, in support of C invariance of isovector electromagnetic interactions

  16. Ternary complexes of folate-PEG-appended dendrimer (G4)/α-cyclodextrin conjugate, siRNA and low-molecular-weight polysaccharide sacran as a novel tumor-selective siRNA delivery system.

    Science.gov (United States)

    Ohyama, Ayumu; Higashi, Taishi; Motoyama, Keiichi; Arima, Hidetoshi

    2017-06-01

    We previously developed a tumor-selective siRNA carrier by preparing polyamidoamine dendrimer (generation 4, G4) conjugates with α-cyclodextrin and folate-polyethylene glycol (Fol-PαC (G4)). In the present study, we developed ternary complexes of Fol-PαC (G4)/siRNA with low-molecular-weight-sacrans to achieve more effective siRNA transfer activity. Among the different molecular-weight sacrans, i.e. sacran 100, 1000 and 10,000 (MW 44,889Da, 943,692Da and 1,488,281Da, respectively), sacran 100 significantly increased the cellular uptake and the RNAi effects of Fol-PαC (G4)/siRNA binary complex with negligible cytotoxicity in KB cells (folate receptor-α positive cells). In addition, the ζ-potential and particle size of Fol-PαC (G4)/siRNA complex were decreased by the ternary complexation with sacran 100. Importantly, the in vivo RNAi effect of the ternary complex after the intravenous administration to tumor-bearing BALB/c mice was significantly higher than that of the binary complex. In conclusion, Fol-PαC (G4)/siRNA/sacran 100 ternary complex has a potential as a novel tumor-selective siRNA delivery system. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Conjugated Polymers Atypically Prepared in Water

    Science.gov (United States)

    Invernale, Michael A.; Pendergraph, Samuel A.; Yavuz, Mustafa S.; Ombaba, Matthew; Sotzing, Gregory A.

    2010-01-01

    Processability remains a fundamental issue for the implementation of conducting polymer technology. A simple synthetic route towards processable precursors to conducting polymers (main chain and side chain) was developed using commercially available materials. These soluble precursor systems were converted to conjugated polymers electrochemically in aqueous media, offering a cheaper and greener method of processing. Oxidative conversion in aqueous and organic media each produced equivalent electrochromics. The precursor method enhances the yield of the electrochromic polymer obtained over that of electrodeposition, and it relies on a less corruptible electrolyte bath. However, electrochemical conversion of the precursor polymers often relies on organic salts and solvents. The ability to achieve oxidative conversion in brine offers a less costly and a more environmentally friendly processing step. It is also beneficial for biological applications. The electrochromics obtained herein were evaluated for electronic, spectral, and morphological properties. PMID:20959869

  18. Conjugation of the CRM197-inulin conjugate significantly increases the immunogenicity of Mycobacterium tuberculosis CFP10-TB10.4 fusion protein.

    Science.gov (United States)

    Hu, Shun; Yu, Weili; Hu, Chunyang; Wei, Dong; Shen, Lijuan; Hu, Tao; Yi, Youjin

    2017-11-01

    Mycobacterium tuberculosis (Mtb) is a serious fatal pathogen that causes tuberculosis (TB). Effective vaccination is urgently needed to deal with the serious threat from TB. Mtb-secreted protein antigens are important virulence determinants of Mtb with poor immunogenicity. Adjuvants and antigen delivery systems are thus highly desired to improve the immunogenicity of protein antigens. Inulin is a biocompatible polysaccharide (PS) adjuvant that can stimulate a strong cellular and humoral immunity. Bacterial capsular PS and haptens have been conjugated with cross-reacting material 197 (CRM 197 ) to improve their immunogenicity. CFP10 and TB10.4 were two Mtb-secreted immunodominant protein antigens. A CFP10-TB10.4 fusion protein (CT) was used as the antigen for covalent conjugation with the CRM 197 -inulin conjugate (CRM-inu). The resultant conjugate (CT-CRM-inu) elicited high CT-specific IgG titers, stimulated splenocyte proliferation and provoked the secretion of Th1-type and Th2-type cytokines. Conjugation with CRM-inu significantly prolonged the systemic circulation of CT and exposure to the immune system. Moreover, CT-CRM-inu showed no apparent toxicity to cardiac, hepatic and renal functions. Thus, conjugation of CT with CRM-inu provided an effective strategy for development of protein-based vaccines against Mtb infection. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Conjugated polymers developed from alkynes

    Institute of Scientific and Technical Information of China (English)

    Yajing Liu; Jacky W.Y.Lam; Ben Zhong Tang

    2015-01-01

    The numerous merits of conjugated polymers(CPs) have encouraged scientists to develop a variety of synthetic routes to CPs with diverse structures and functionalities. Among the large scope of substrates,alkyne plays an important role in constructing polymers with conjugated backbones. In addition to some well-developed reactions including Glaser–Hay and Sonogashira coupling, azide/thiol-yne click reaction and cyclotrimerization, some novel alkyne-based reactions have also been explored such as oxidative polycoupling, decarbonylative polycoupling and multicomponent tandem polymerizations. his review focuses on the recent progress on the synthetic methodology of CPs in the last ive years using monomers with two or more triple bonds and some of their high-technological applications. Selected examples of materials properties of these CPs are given in this review, such as luorescence response to chemical or physical stimuli, magnetism, white light emission, cell imaging and bioprobing. Finally, a short perspective is raised in regard to the outlook of the preparation methodologies, functionalities as well as potential applications of CPs in the future.

  20. Subgap Absorption in Conjugated Polymers

    Science.gov (United States)

    Sinclair, M.; Seager, C. H.; McBranch, D.; Heeger, A. J; Baker, G. L.

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination.

  1. Subgap absorption in conjugated polymers

    Energy Technology Data Exchange (ETDEWEB)

    Sinclair, M.; Seager, C.H. (Sandia National Labs., Albuquerque, NM (USA)); McBranch, D.; Heeger, A.J. (California Univ., Santa Barbara, CA (USA)); Baker, G.L. (Bell Communications Research, Inc., Red Bank, NJ (USA))

    1991-01-01

    Along with X{sup (3)}, the magnitude of the optical absorption in the transparent window below the principal absorption edge is an important parameter which will ultimately determine the utility of conjugated polymers in active integrated optical devices. With an absorptance sensitivity of < 10{sup {minus}5}, Photothermal Deflection Spectroscopy (PDS) is ideal for determining the absorption coefficients of thin films of transparent'' materials. We have used PDS to measure the optical absorption spectra of the conjugated polymers poly(1,4-phenylene-vinylene) (and derivitives) and polydiacetylene-4BCMU in the spectral region from 0.55 eV to 3 eV. Our spectra show that the shape of the absorption edge varies considerably from polymer to polymer, with polydiacetylene-4BCMU having the steepest absorption edge. The minimum absorption coefficients measured varied somewhat with sample age and quality, but were typically in the range 1 cm{sup {minus}1} to 10 cm{sup {minus}1}. In the region below 1 eV, overtones of C-H stretching modes were observed, indicating that further improvements in transparency in this spectral region might be achieved via deuteration of fluorination. 11 refs., 4 figs.

  2. Parallel conjugate gradient algorithms for manipulator dynamic simulation

    Science.gov (United States)

    Fijany, Amir; Scheld, Robert E.

    1989-01-01

    Parallel conjugate gradient algorithms for the computation of multibody dynamics are developed for the specialized case of a robot manipulator. For an n-dimensional positive-definite linear system, the Classical Conjugate Gradient (CCG) algorithms are guaranteed to converge in n iterations, each with a computation cost of O(n); this leads to a total computational cost of O(n sq) on a serial processor. A conjugate gradient algorithms is presented that provide greater efficiency using a preconditioner, which reduces the number of iterations required, and by exploiting parallelism, which reduces the cost of each iteration. Two Preconditioned Conjugate Gradient (PCG) algorithms are proposed which respectively use a diagonal and a tridiagonal matrix, composed of the diagonal and tridiagonal elements of the mass matrix, as preconditioners. Parallel algorithms are developed to compute the preconditioners and their inversions in O(log sub 2 n) steps using n processors. A parallel algorithm is also presented which, on the same architecture, achieves the computational time of O(log sub 2 n) for each iteration. Simulation results for a seven degree-of-freedom manipulator are presented. Variants of the proposed algorithms are also developed which can be efficiently implemented on the Robot Mathematics Processor (RMP).

  3. A nanodiamond-fluorescein conjugate for cell studies

    Science.gov (United States)

    Pedroso-Santana, Seidy; Fleitas-Salazar, Noralvis; Sarabia-Sainz, Andrei; Silva-Campa, Erika; Burgara-Estrella, Alexel; Angulo-Molina, Aracely; Melendrez, Rodrigo; Pedroza-Montero, Martin; Riera, Raul

    2018-03-01

    The use of nanodiamonds in studies with living systems generally involves the modification of their surfaces with functional groups. Fluorescent molecules can be attached to these groups, so that one can know the exact position of the particles in each moment of the interaction with the cells. Here we modify the surface of detonation nanodiamonds and nitrogen-vacancy center nanodiamonds using carboxylation and hydroxylation procedures. Subsequent reactions with silicates and cysteine, before addition of fluorescein allow to obtain fluorescent nano-conjugates. We used confocal microscopy to observe the position of nanodiamonds interacting with HeLa cells. At 3 h post-incubation the green fluorescence is localized in extracellular rounded like-vesicles assemblies while at 24 h the conjugates can be observed inside the cells. The measurement of the fluorescence emitted by both conjugates allowed to find an enhanced emission of fluorescein isothiocyanate (FITC) when the nitrogen-vacancy center is present. We propose the existence of a fluorescence enhancement by electron transference process. The procedure described in this work allows the functionalization of nanodiamonds with FITC and other molecules using functional surface groups and small size mediators. Also, as was proved in our work, the nanodiamond-fluorescein conjugates can be used to track nanoparticles position within the cell. Localization studies are particularly important for drug delivery applications of nanodiamonds.

  4. Target binding improves relaxivity in aptamer-gadolinium conjugates.

    Science.gov (United States)

    Bernard, Elyse D; Beking, Michael A; Rajamanickam, Karunanithi; Tsai, Eve C; Derosa, Maria C

    2012-12-01

    MRI contrast agents (CA) have been heavily used over the past several decades to enhance the diagnostic value of the obtained images. From a design perspective, two avenues to improve the efficacy of contrast agents are readily evident: optimization of magnetic properties of the CA, and optimization of the pharmacokinetics and distribution of the CA in the patient. Contrast agents consisting of DNA aptamer-gadolinium(III) conjugates provide a single system in which these factors can be addressed simultaneously. In this proof-of-concept study, the 15mer thrombin aptamer was conjugated to diethylenetriaminepentaacetic (DTPA) dianhydride to form a monoamide derivative of the linear open-chain chelate present in the commonly used contrast agent Magnevist(®). The stability of the conjugated DNA aptamer-DTPA-Gd(III) chelate in a transmetallation study using Zn(II) was found to be similar to that reported for DTPA-Gd(III). Relaxivity enhancements of 35 ± 4 and 20 ± 1 % were observed in the presence of thrombin compared to a control protein at fields of 9.4 and 1.5 T, respectively. The inclusion of spacers between the aptamer and the DTPA to eliminate possible steric effects was also investigated but not found to improve the relaxation enhancement achieved in comparison to the unaltered aptamer conjugate.

  5. Production of carrier-peptide conjugates using chemically reactive unnatural amino acids

    Science.gov (United States)

    Young, Travis; Schultz, Peter G

    2013-12-17

    Provided are methods of making carrier polypeptide that include incorporating a first unnatural amino acid into a carrier polypeptide variant, incorporating a second unnatural amino acid into a target polypeptide variant, and reacting the first and second unnatural amino acids to produce the conjugate. Conjugates produced using the provided methods are also provided. In addition, orthogonal translation systems in methylotrophic yeast and methods of using these systems to produce carrier and target polypeptide variants comprising unnatural amino acids are provided.

  6. Uptake of Single-Walled Carbon Nanotubes Conjugated with DNA by Microvascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Joseph Harvey

    2012-01-01

    Full Text Available Single-walled carbon nanotubes (SWCNTs have been proposed to have great therapeutic potential. SWCNTs conjugated with drugs or genes travel in the systemic circulation to reach target cells or tissues following extravasation from microvessels although the interaction between SWCNT conjugates and the microvascular endothelial cells (ECs remains unknown. We hypothesized that SWCNT-DNA conjugates would be taken up by microvascular ECs and that this process would be facilitated by SWCNTs compared to facilitation by DNA alone. ECs were treated with various concentrations of SWCNT-DNA-FITC conjugates, and the uptake and intracellular distribution of these conjugates were determined by a confocal microscope imaging system followed by quantitative analysis of fluorescence intensity. The uptake of SWCNT-DNA-FITC conjugates (2 μg/mL by microvascular ECs was significantly greater than that of DNA-FITC (2 μg/mL, observed at 6 hrs after treatment. For the intracellular distribution, SWCNT-DNA-FITC conjugates were detected in the nucleus of ECs, while DNA-FITC was restricted to the cytoplasm. The fluorescence intensity and distribution of SWCNTs were concentration and time independent. The findings demonstrate that SWCNTs facilitate DNA delivery into microvascular ECs, thus suggesting that SWCNTs serving as drug and gene vehicles have therapeutic potential.

  7. Preconditioning the modified conjugate gradient method ...

    African Journals Online (AJOL)

    In this paper, the convergence analysis of the conventional conjugate Gradient method was reviewed. And the convergence analysis of the modified conjugate Gradient method was analysed with our extension on preconditioning the algorithm. Convergence of the algorithm is a function of the condition number of M-1A.

  8. DENDRIMER CONJUGATES FOR SELECTIVE OF PROTEIN AGGREGATES

    DEFF Research Database (Denmark)

    2004-01-01

    Dendrimer conjugates are presented, which are formed between a dendrimer and a protein solubilising substance. Such dendrimer conjugates are effective in the treatment of protein aggregate-related diseases (e.g. prion-related diseases). The protein solubilising substance and the dendrimer together...

  9. Tetrafullerene conjugates for all-organic photovoltaics

    NARCIS (Netherlands)

    Fernández, G.; Sánchez, L.; Veldman, D.; Wienk, M.M.; Atienza, C.M.; Guldi, D.M.; Janssen, R.A.J.; Martin, N.

    2008-01-01

    The synthesis of two new tetrafullerene nanoconjugates in which four C60 units are covalently connected through different -conjugated oligomers (oligo(p-phenylene ethynylene) and oligo(p-phenylene vinylene)) is described. The photovoltaic (PV) response of these C60-based conjugates was evaluated by

  10. CONJUGATED BLOCK-COPOLYMERS FOR ELECTROLUMINESCENT DIODES

    NARCIS (Netherlands)

    Hilberer, A; Gill, R.E; Herrema, J.K; Malliaras, G.G; Wildeman, J.; Hadziioannou, G

    In this article we review results obtained in our laboratory on the design and study of new light-emitting polymers. We are interested in the synthesis and characterisation of block copolymers with regularly alternating conjugated and non conjugated sequences. The blocks giving rise to luminescence

  11. The Conjugate Acid-Base Chart.

    Science.gov (United States)

    Treptow, Richard S.

    1986-01-01

    Discusses the difficulties that beginning chemistry students have in understanding acid-base chemistry. Describes the use of conjugate acid-base charts in helping students visualize the conjugate relationship. Addresses chart construction, metal ions, buffers and pH titrations, and the organic functional groups and nonaqueous solvents. (TW)

  12. Bio-Conjugates for Nanoscale Applications

    DEFF Research Database (Denmark)

    Villadsen, Klaus

    Bio-conjugates for Nanoscale Applications is the title of this thesis, which covers three different projects in chemical bio-conjugation research, namely synthesis and applications of: Lipidated fluorescent peptides, carbohydrate oxime-azide linkers and N-aryl O-R2 oxyamine derivatives. Lipidated...

  13. Class, Kinship Density, and Conjugal Role Segregation.

    Science.gov (United States)

    Hill, Malcolm D.

    1988-01-01

    Studied conjugal role segregation in 150 married women from intact families in working-class community. Found that, although involvement in dense kinship networks was associated with conjugal role segregation, respondents' attitudes toward marital roles and phase of family cycle when young children were present were more powerful predictors of…

  14. Misonidazole-glutathione conjugates in CHO cells

    International Nuclear Information System (INIS)

    Varghese, A.J.; Whitmore, G.F.

    1984-01-01

    Misonidazole, after reduction to the hydroxylamine derivative, reacts with glutathione (GSH) under physiological conditions. The reaction product has been identified as a mixture of two isomeric conjugates. When water soluble extracts of CHO cells exposed to misonidazole under hypoxic conditions are subjected to HPLC analysis, misonidazole derivatives, having the same chromatographic properties as the GSH-MISO conjugates, were detected. When CHO cells were incubated with misonidazole in the presence of added GSH, a substantial increase in the amount of the conjugate was detected. When extracts of CHO cells exposed to misonidazole under hypoxia were subsequently exposed to GSH, an increased formation of the conjugate was observed. A rearrangement product of the hydroxylamine derivative of misonidazole is postulated as the reactive intermediate responsible for the formation of the conjugate

  15. Identification of novel autophagic Radix Polygalae fraction by cell membrane chromatography and UHPLC-(Q)TOF-MS for degradation of neurodegenerative disease proteins

    OpenAIRE

    An-Guo Wu; Vincent Kam-Wai Wong; Wu Zeng; Liang Liu; Betty Yuen-Kwan Law

    2015-01-01

    With its traditional use in relieving insomnia and anxiety, our previous study has identified onjisaponin B from Radix Polygalae (RP), as a novel autophagic enhancer with potential neuroprotective effects. In current study, we have further identified a novel active fraction from RP, contains 17 major triterpenoid saponins including the onjisaponin B, by the combinational use of cell membrane chromatography (CMC) and ultra-performance liquid chromatography coupled to (quadrupole) time-of-fligh...

  16. Beneficial Autophagic Activities, Mitochondrial Function, and Metabolic Phenotype Adaptations Promoted by High-Intensity Interval Training in a Rat Model

    Directory of Open Access Journals (Sweden)

    Fang-Hui Li

    2018-05-01

    Full Text Available The effects of high-intensity interval (HIIT and moderate-intensity continuous training (MICT on basal autophagy and mitochondrial function in cardiac and skeletal muscle and plasma metabolic phenotypes have not been clearly characterized. Here, we investigated how 10-weeks HIIT and MICT differentially modify basal autophagy and mitochondrial markers in cardiac and skeletal muscle and conducted an untargeted metabolomics study with proton nuclear magnetic resonance (1H NMR spectroscopy and multivariate statistical analysis of plasma metabolic phenotypes. Male Sprague–Dawley rats were separated into three groups: sedentary control (SED, MICT, and HIIT. Rats underwent evaluation of exercise performance, including exercise tolerance and grip strength, and blood lactate levels were measured immediately after an incremental exercise test. Plasma samples were analyzed by 1H NMR. The expression of autophagy and mitochondrial markers and autophagic flux (LC3II/LC3-I ratio in cardiac, rectus femoris, and soleus muscle were analyzed by western blotting. Time to exhaustion and grip strength increased significantly following HIIT compared with that in both SED and MICT groups. Compared with those in the SED group, blood lactate level, and the expression of SDH, COX-IV, and SIRT3 significantly increased in rectus femoris and soleus muscle of both HIIT and MICT groups. Meanwhile, SDH and COX-IV content of cardiac muscle and COX-IV and SIRT3 content of rectus femoris and soleus muscle increased significantly following HIIT compared with that following MICT. The expression of LC3-II, ATG-3, and Beclin-1 and LC3II/LC3-I ratio were significantly increased only in soleus and cardiac muscle following HIIT. These data indicate that HIIT was more effective for improving physical performance and facilitating cardiac and skeletal muscle adaptations that increase mitochondrial function and basal autophagic activities. Moreover, 1H NMR spectroscopy and multivariate

  17. Beneficial Autophagic Activities, Mitochondrial Function, and Metabolic Phenotype Adaptations Promoted by High-Intensity Interval Training in a Rat Model.

    Science.gov (United States)

    Li, Fang-Hui; Li, Tao; Ai, Jing-Yi; Sun, Lei; Min, Zhu; Duan, Rui; Zhu, Ling; Liu, Yan-Ying; Liu, Timon Cheng-Yi

    2018-01-01

    The effects of high-intensity interval (HIIT) and moderate-intensity continuous training (MICT) on basal autophagy and mitochondrial function in cardiac and skeletal muscle and plasma metabolic phenotypes have not been clearly characterized. Here, we investigated how 10-weeks HIIT and MICT differentially modify basal autophagy and mitochondrial markers in cardiac and skeletal muscle and conducted an untargeted metabolomics study with proton nuclear magnetic resonance ( 1 H NMR) spectroscopy and multivariate statistical analysis of plasma metabolic phenotypes. Male Sprague-Dawley rats were separated into three groups: sedentary control (SED), MICT, and HIIT. Rats underwent evaluation of exercise performance, including exercise tolerance and grip strength, and blood lactate levels were measured immediately after an incremental exercise test. Plasma samples were analyzed by 1 H NMR. The expression of autophagy and mitochondrial markers and autophagic flux (LC3II/LC3-I ratio) in cardiac, rectus femoris, and soleus muscle were analyzed by western blotting. Time to exhaustion and grip strength increased significantly following HIIT compared with that in both SED and MICT groups. Compared with those in the SED group, blood lactate level, and the expression of SDH, COX-IV, and SIRT3 significantly increased in rectus femoris and soleus muscle of both HIIT and MICT groups. Meanwhile, SDH and COX-IV content of cardiac muscle and COX-IV and SIRT3 content of rectus femoris and soleus muscle increased significantly following HIIT compared with that following MICT. The expression of LC3-II, ATG-3, and Beclin-1 and LC3II/LC3-I ratio were significantly increased only in soleus and cardiac muscle following HIIT. These data indicate that HIIT was more effective for improving physical performance and facilitating cardiac and skeletal muscle adaptations that increase mitochondrial function and basal autophagic activities. Moreover, 1 H NMR spectroscopy and multivariate statistical

  18. The integral membrane protein ITM2A, a transcriptional target of PKA-CREB, regulates autophagic flux via interaction with the vacuolar ATPase.

    Science.gov (United States)

    Namkoong, Sim; Lee, Kang Il; Lee, Jin I; Park, Rackhyun; Lee, Eun-Ju; Jang, Ik-Soon; Park, Junsoo

    2015-01-01

    The PKA-CREB signaling pathway is involved in many cellular processes including autophagy. Recent studies demonstrated that PKA-CREB inhibits autophagy in yeast; however, the role of PKA-CREB signaling in mammalian cell autophagy has not been fully characterized. Here, we report that the integral membrane protein ITM2A expression is positively regulated by PKA-CREB signaling and ITM2A expression interferes with autophagic flux by interacting with vacuolar ATPase (v-ATPase). The ITM2A promoter contains a CRE element, and mutation at the CRE consensus site decreases the promoter activity. Forskolin treatment and PKA expression activate the ITM2A promoter confirming that ITM2A expression is dependent on the PKA-CREB pathway. ITM2A expression results in the accumulation of autophagosomes and interferes with autolysosome formation by blocking autophagic flux. We demonstrated that ITM2A physically interacts with v-ATPase and inhibits lysosomal function. These results support the notion that PKA-CREB signaling pathway regulates ITM2A expression, which negatively regulates autophagic flux by interfering with the function of v-ATPase.

  19. Fluoxetine induces autophagic cell death via eEF2K-AMPK-mTOR-ULK complex axis in triple negative breast cancer.

    Science.gov (United States)

    Sun, Dejuan; Zhu, Lingjuan; Zhao, Yuqian; Jiang, Yingnan; Chen, Lixia; Yu, Yang; Ouyang, Liang

    2018-04-01

    Triple negative breast cancer (TNBC) is a complex and intrinsically aggressive tumour with poor prognosis, and the discovery of targeted small-molecule drugs for TNBC treatment still remains in its infancy. In this study, we aimed to discover a small-molecule agent for TNBC treatment and illuminate its potential mechanisms. Cell viability was detected by using methylthiazoltetrazolium (MTT) assay. Electron microscopy, GFP-LC3 transfection, monodansylcadaverine staining and apoptosis assay were performed to determine Fluoxetine-induced autophagy and apoptosis. Western blotting and siRNA transfection were carried out to investigate the mechanisms of Fluoxetine-induced autophagy. iTRAQ-based proteomics analysis was used to explore the underlying mechanisms. We have demonstrated that Fluoxetine had remarkable anti-proliferative activities and induced autophagic cell death in MDA-MB-231 and MDA-MB-436 cells. The mechanism for Fluoxetine-induced autophagic cell death was associated with inhibition of eEF2K and activation of AMPK-mTOR-ULK complex axis. Further iTRAQ-based proteomics and network analyses revealed that Fluoxetine-induced mechanism was involved in BIRC6, BNIP1, SNAP29 and Bif-1. These results demonstrate that Fluoxetine induces apoptosis and autophagic cell death in TNBC, which will hold a promise for the future TNBC therapy. © 2017 John Wiley & Sons Ltd.

  20. PF-4708671, a specific inhibitor of p70 ribosomal S6 kinase 1, activates Nrf2 by promoting p62-dependent autophagic degradation of Keap1

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jeong Su [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Kang, Dong Hoon [Department of Life Science and Ewha Research Center for Systems Biology (Korea, Republic of); The Research Center for Cell Homeostasis, Ewha Womans University, Seoul 127-750 (Korea, Republic of); Lee, Da Hyun [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of); Bae, Soo Han, E-mail: soohanbae@yuhs.ac [Severance Biomedical Science Institute (Korea, Republic of); Yonsei Biomedical Research Institute, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-752 (Korea, Republic of)

    2015-10-23

    p70 ribosomal S6 kinase 1 (S6K1) is an important serine/threonine kinase and downstream target of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway. PF-4708671 is a specific inhibitor of S6K1, and prevents S6K1-mediated phosphorylation of the S6 protein. PF-4708671 treatment often leads to apoptotic cell death. However, the protective mechanism against PF-4708671-induced cell death has not been elucidated. The nuclear factor erythroid 2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway is essential for protecting cells against oxidative stress. p62, an adaptor protein in the autophagic process, enhances Nrf2 activation through the impairment of Keap1 activity. In this study, we showed that PF-4708671 induces autophagic Keap1 degradation-mediated Nrf2 activation in p62-dependent manner. Furthermore, p62-dependent Nrf2 activation plays a crucial role in protecting cells from PF-4708671-mediated apoptosis. - Highlights: • PF-4708671, a S6K1-specific inhibitor, prevents S6K1-mediated S6 phosphorylation. • However, PF-4708671 treatment often leads to apoptotic cell death. • Protective mechanism against PF-4708671-induced cell death remains to be elucidated. • PF-4708671 induced p62-dependent, autophagic Keap1 degradation-mediated Nrf2 activation. • p62-dependent Nrf2 activation protects cells from PF-4708671-mediated apoptosis.

  1. Lipidation of BmAtg8 is required for autophagic degradation of p62 bodies containing ubiquitinated proteins in the silkworm, Bombyx mori.

    Science.gov (United States)

    Ji, Ming-Ming; Lee, Jae Man; Mon, Hiroaki; Iiyama, Kazuhiro; Tatsuke, Tsuneyuki; Morokuma, Daisuke; Hino, Masato; Yamashita, Mami; Hirata, Kazuma; Kusakabe, Takahiro

    2017-10-01

    p62/Sequestosome-1 (p62/SQSTM1, hereafter referred to as p62) is a major adaptor that allows ubiquitinated proteins to be degraded by autophagy, and Atg8 homologs are required for p62-mediated autophagic degradation, but their relationship is still not understood in Lepidopteran insects. Here it is clearly demonstrated that the silkworm homolog of mammalian p62, Bombyx mori p62 (Bmp62), forms p62 bodies depending on its Phox and Bem1p (PB1) and ubiquitin-associated (UBA) domains. These two domains are associated with Bmp62 binding to ubiquitinated proteins to form the p62 bodies, and the UBA domain is essential for the binding, but Bmp62 still self-associates without the PB1 or UBA domain. The p62 bodies in Bombyx cells are enclosed by BmAtg9-containing membranes and degraded via autophagy. It is revealed that the interaction between the Bmp62 AIM motif and BmAtg8 is critical for the autophagic degradation of the p62 bodies. Intriguingly, we further demonstrate that lipidation of BmAtg8 is required for the Bmp62-mediated complete degradation of p62 bodies by autophagy. Our results should be useful in future studies of the autophagic mechanism in Lepidopteran insects. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. AoAtg26, a putative sterol glucosyltransferase, is required for autophagic degradation of peroxisomes, mitochondria, and nuclei in the filamentous fungus Aspergillus oryzae.

    Science.gov (United States)

    Kikuma, Takashi; Tadokoro, Takayuki; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

    2017-02-01

    Autophagy is a conserved process in eukaryotic cells for degradation of cellular proteins and organelles. In filamentous fungi, autophagic degradation of organelles such as peroxisomes, mitochondria, and nuclei occurs in basal cells after the prolonged culture, but its mechanism is not well understood. Here, we functionally analyzed the filamentous fungus Aspergillus oryzae AoAtg26, an ortholog of the sterol glucosyltransferase PpAtg26 involved in pexophagy in the yeast Pichia pastoris. Deletion of Aoatg26 caused a severe decrease in conidiation and aerial hyphae formation, which is typically observed in the autophagy-deficient A. oryzae strains. In addition, cup-shaped AoAtg8-positive membrane structures were accumulated in the Aoatg26 deletion strain, indicating that autophagic process is impaired. Indeed, the Aoatg26 deletion strain was defective in the degradation of peroxisomes, mitochondria, and nuclei. Taken together, AoAtg26 plays an important role for autophagic degradation of organelles in A. oryzae, which may physiologically contribute to the differentiation in filamentous fungi.

  3. Diclofenac in Arabidopsis cells: Rapid formation of conjugates.

    Science.gov (United States)

    Fu, Qiuguo; Ye, Qingfu; Zhang, Jianbo; Richards, Jaben; Borchardt, Dan; Gan, Jay

    2017-03-01

    Pharmaceutical and personal care products (PPCPs) are continuously introduced into the soil-plant system, through practices such as agronomic use of reclaimed water and biosolids containing these trace contaminants. Plants may accumulate PPCPs from soil, serving as a conduit for human exposure. Metabolism likely controls the final accumulation of PPCPs in plants, but is in general poorly understood for emerging contaminants. In this study, we used diclofenac as a model compound, and employed 14 C tracing, and time-of-flight (TOF) and triple quadruple (QqQ) mass spectrometers to unravel its metabolism pathways in Arabidopsis thaliana cells. We further validated the primary metabolites in Arabidopsis seedlings. Diclofenac was quickly taken up into A. thaliana cells. Phase I metabolism involved hydroxylation and successive oxidation and cyclization reactions. However, Phase I metabolites did not accumulate appreciably; they were instead rapidly conjugated with sulfate, glucose, and glutamic acid through Phase II metabolism. In particular, diclofenac parent was directly conjugated with glutamic acid, with acyl-glutamatyl-diclofenac accounting for >70% of the extractable metabolites after 120-h incubation. In addition, at the end of incubation, >40% of the spiked diclofenac was in the non-extractable form, suggesting extensive sequestration into cell matter. The rapid formation of non-extractable residue and dominance of diclofenac-glutamate conjugate uncover previously unknown metabolism pathways for diclofenac. In particular, the rapid conjugation of parent highlights the need to consider conjugates of emerging contaminants in higher plants, and their biological activity and human health implications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Naked-eye 3D imaging employing a modified MIMO micro-ring conjugate mirrors

    Science.gov (United States)

    Youplao, P.; Pornsuwancharoen, N.; Amiri, I. S.; Thieu, V. N.; Yupapin, P.

    2018-03-01

    In this work, the use of a micro-conjugate mirror that can produce the 3D image incident probe and display is proposed. By using the proposed system together with the concept of naked-eye 3D imaging, a pixel and a large volume pixel of a 3D image can be created and displayed as naked-eye perception, which is valuable for the large volume naked-eye 3D imaging applications. In operation, a naked-eye 3D image that has a large pixel volume will be constructed by using the MIMO micro-ring conjugate mirror system. Thereafter, these 3D images, formed by the first micro-ring conjugate mirror system, can be transmitted through an optical link to a short distance away and reconstructed via the recovery conjugate mirror at the other end of the transmission. The image transmission is performed by the Fourier integral in MATLAB and compares to the Opti-wave program results. The Fourier convolution is also included for the large volume image transmission. The simulation is used for the manipulation, where the array of a micro-conjugate mirror system is designed and simulated for the MIMO system. The naked-eye 3D imaging is confirmed by the concept of the conjugate mirror in both the input and output images, in terms of the four-wave mixing (FWM), which is discussed and interpreted.

  5. Adverse events following quadrivalent meningococcal CRM-conjugate vaccine (Menveo®) reported to the Vaccine Adverse Event Reporting system (VAERS), 2010-2015.

    Science.gov (United States)

    Myers, Tanya R; McNeil, Michael M; Ng, Carmen S; Li, Rongxia; Lewis, Paige W; Cano, Maria V

    2017-03-27

    Limited data are available describing the post-licensure safety of meningococcal vaccines, including Menveo®. We reviewed reports of adverse events (AEs) to the Vaccine Adverse Event Reporting System (VAERS) to assess safety in all age groups. VAERS is a national spontaneous vaccine safety surveillance system co-administered by the Centers for Disease Control and Prevention and the US Food and Drug Administration. We searched the VAERS database for US reports of adverse events in persons who received Menveo from 1 January 2010 through 31 December 2015. We clinically reviewed reports and available medical records for serious AEs, selected pre-specified outcomes, and vaccination during pregnancy. We used empirical Bayesian data mining to identify AEs that were disproportionately reported after receipt of Menveo. During the study period, VAERS received 2614 US reports after receipt of Menveo. Of these, 67 were classified as serious, including 1 report of death. Adolescents (aged 11-18years) accounted for 74% of reports. Most of the reported AEs were non-serious and described AEs consistent with data from pre-licensure studies. Anaphylaxis and syncope were the two most common events in the serious reports. We did not identify any new safety concerns after review of AEs that exceeded the data mining threshold, although we did observe disproportionate reporting for terms that were not associated with an adverse event (e.g., "incorrect drug dosage form administered", "wrong technique in drug usage process"). Although reports were limited, we did not find any evidence for concern regarding the use of Menveo during pregnancy. In our review of VAERS reports, findings of AEs were consistent with the data from pre-licensure studies. Vaccine providers should continue to emphasize and adhere to proper administration of the vaccine. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Crystal structure of an iridium(III complex of the [C(dppm2] PCP pincer ligand system and its conjugate CH acid form

    Directory of Open Access Journals (Sweden)

    Christian Reitsamer

    2018-05-01

    Full Text Available After the successful creation of the newly designed PCP carbodiphosphorane (CDP ligand [Reitsamer et al. (2012. Dalton Trans. 41, 3503–3514; Stallinger et al. (2007. Chem. Commun. pp. 510–512], the treatment of this PCP pincer system with the transition metal iridium and further the analysis of the structures by single-crystal diffraction and by NMR spectroscopy were of major interest. Two different iridium complexes, namely (bis{[(diphenylphosphanylmethyl]diphenylphosphanylidene}methane-κ3P,C,P′carbonylchloridohydridoiridium(III chloride dichloromethane trisolvate, [IrIII(CO{C(dppm2-κ3P,C,P′}ClH]Cl·3CH2Cl2 (1 and the closely related (bis{[(diphenylphosphanylmethyl]diphenylphosphanylidene}methanide(1+-κ3P,C,P′carbonylchloridohydridoiridium(III dichloride–hydrochloric acid–water (1/2/5.5, [IrIII(CO{CH(dppm2-κ3P,C,P′ClH]Cl}2 (2, have been designed and both complexes show a slightly distorted octahedral coordinated IrIII centre. The PCP pincer ligand system is arranged in a meridional manner, the CO ligand is located trans to the central PCP carbon and a hydride and chloride are located perpendicular above and below the P2C2 plane. With an Ir—CCDP distance of 2.157 (5 Å, an Ir—CO distance of 1.891 (6 Å and a quite short C—O distance of 1.117 (7 Å, complex 1 presents a strong carbonyl bond. Complex 2, the corresponding CH acid of 1, shows an additionally attached proton at the carbodiphosphorane carbon atom located antiperiplanar to the hydride of the metal centre. In comparison with complex 1, the Ir—CCDP distance of 2.207 (3 Å is lengthened and the Ir—C—O values indicate a weaker trans influence of the central carbodiphosphorane carbon atom.

  7. Synthesis, characterization, mucoadhesion and biocompatibility of thiolated carboxymethyl dextran-cysteine conjugate.

    Science.gov (United States)

    Shahnaz, G; Perera, G; Sakloetsakun, D; Rahmat, D; Bernkop-Schnürch, A

    2010-05-21

    This study was aimed at improving the mucoadhesive properties of carboxymethyl dextran by the covalent attachment of cysteine. Mediated by a carbodiimide, l-cysteine was covalently attached to the polymer. The resulting CMD-cysteine conjugate (CMD-(273) conjugate) displayed 273+/-20 micromol thiol groups per gram of polymer (mean+/-S.D.; n=3). Within 2h the viscosity of an aqueous mucus/CMD-(273) conjugate mixture pH 7.4 increased at 37 degrees C by more than 85% compared to a mucus/carboxymethyl dextran mixture indicating enlarged interactions between the mucus and the thiolated polymer. Due to the immobilization of cysteine, the swelling velocity of the polymer was significantly accelerated (ppolymer disintegrated within 15 min, whereas tablets of the CMD-(273) conjugate remained stable for 160 min (means+/-S.D.; n=3). Results from LDH and MTT assays on Caco-2 cells revealed 4.96+/-0.98% cytotoxicity and 94.1+/-0.9% cell viability for the CMD-(273) conjugate, respectively. Controlled release of model compound from CMD-(273) conjugate tablets was observed over 6h. These findings suggest that CMD-(273) conjugate is a promising novel polymer for drug delivery systems providing improved mucoadhesive and cohesive properties, greater stability and biocompatibility. Copyright 2010 Elsevier B.V. All rights reserved.

  8. Peptide- and saccharide-conjugated dendrimers for targeted drug delivery: a concise review

    Science.gov (United States)

    Liu, Jie; Gray, Warren D.; Davis, Michael E.; Luo, Ying

    2012-01-01

    Dendrimers comprise a category of branched materials with diverse functions that can be constructed with defined architectural and chemical structures. When decorated with bioactive ligands made of peptides and saccharides through peripheral chemical groups, dendrimer conjugates are turned into nanomaterials possessing attractive binding properties with the cognate receptors. At the cellular level, bioactive dendrimer conjugates can interact with cells with avidity and selectivity, and this function has particularly stimulated interests in investigating the targeting potential of dendrimer materials for the design of drug delivery systems. In addition, bioactive dendrimer conjugates have so far been studied for their versatile capabilities to enhance stability, solubility and absorption of various types of therapeutics. This review presents a brief discussion on three aspects of the recent studies to use peptide- and saccharide-conjugated dendrimers for drug delivery: (i) synthesis methods, (ii) cell- and tissue-targeting properties and (iii) applications of conjugated dendrimers in drug delivery nanodevices. With more studies to elucidate the structure–function relationship of ligand–dendrimer conjugates in transporting drugs, the conjugated dendrimers hold promise to facilitate targeted delivery and improve drug efficacy for discovery and development of modern pharmaceutics. PMID:23741608

  9. Ti-Catalyzed Hydroamination for the Synthesis of Amine-Containing π-Conjugated Materials.

    Science.gov (United States)

    Hao, Han; Thompson, Kyle A; Hudson, Zachary M; Schafer, Laurel L

    2018-04-11

    A series of conjugated enamines were prepared by Ti catalyzed anti-Markovnikov hydroamination. The synthetic route is efficient with yields of up to 94 % and the 100 % atom efficiency of the reaction means that these products are easily isolated and purified. Due to the extended conjugated system, the enamine tautomers were observed exclusively in both solid and solution phases, as determined by X-ray crystallography and NMR spectroscopy. These new conjugated molecules, with N incorporated into the backbone, show interesting photophysical properties including photo-luminescent quantum yields of up to 0.26. Notably, through the incorporation of B to give a donor-acceptor π-conjugated system, a redshift of approximately 100 nm is observed for the emission maximum along with the anticipated solvatochromic shifts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Application of heat-balance integral method to conjugate thermal explosion

    Directory of Open Access Journals (Sweden)

    Novozhilov Vasily

    2009-01-01

    Full Text Available Conjugate thermal explosion is an extension of the classical theory, proposed and studied recently by the author. The paper reports application of heat-balance integral method for developing phase portraits for systems undergoing conjugate thermal explosion. The heat-balance integral method is used as an averaging method reducing partical differential equation problem to the set of first-order ordinary differential equations. The latter reduced problem allows natural interpretation in appropriately chosen phase space. It is shown that, with the help of heat-balance integral technique, conjugate thermal explosion problem can be described with a good accuracy by the set of non-linear first-order differential equations involving complex error function. Phase trajectories are presented for typical regimes emerging in conjugate thermal explosion. Use of heat-balance integral as a spatial averaging method allows efficient description of system evolution to be developed.

  11. DNA-templated antibody conjugation for targeted drug delivery to cancer cells

    DEFF Research Database (Denmark)

    Liu, Tianqiang

    2016-01-01

    -templated organic synthesis due to the wide existence of the 3-histidine cluster in most wild-type proteins. In this thesis, three projects that relate to targeted drug delivery to cancer cells based on the DTPC method is described. The first project was a delivery system which uses transferrin as the targeting....... The study shows that DNA is a highly useful tool for the assembly of proteins with potential therapeutic applications. The DNA-templated protein conjugation shows a promising application in constructing antibody-toxin conjugates or antibody-drug conjugates. In addition, DNA strands used for antibody...... either antibody engineering or special expression systems and are both time and labor consuming. To avoid the drawbacks caused by conventional chemical modification and recombinant methodologies, an ideal site specific conjugation technique would use natural amino acid residues to the protein by a new...

  12. The Role of Neurotrophic Factors Conjugated to Iron Oxide Nanoparticles in Peripheral Nerve Regeneration: In Vitro Studies

    Directory of Open Access Journals (Sweden)

    Ofra Ziv-Polat

    2014-01-01

    Full Text Available Local delivery of neurotrophic factors is a pillar of neural repair strategies in the peripheral nervous system. The main disadvantage of the free growth factors is their short half-life of few minutes. In order to prolong their activity, we have conjugated to iron oxide nanoparticles three neurotrophic factors: nerve growth factor (βNGF, glial cell-derived neurotrophic factor (GDNF, and basic fibroblast growth factor (FGF-2. Comparative stability studies of free versus conjugated factors revealed that the conjugated neurotrophic factors were significantly more stable in tissue cultures and in medium at 37°C. The biological effects of free versus conjugated neurotrophic factors were examined on organotypic dorsal root ganglion (DRG cultures performed in NVR-Gel, composed mainly of hyaluronic acid and laminin. Results revealed that the conjugated neurotrophic factors enhanced early nerve fiber sprouting compared to the corresponding free factors. The most meaningful result was that conjugated-GDNF, accelerated the onset and progression of myelin significantly earlier than the free GDNF and the other free and conjugated factors. This is probably due to the beneficial and long-acting effect that the stabilized conjugated-GDNF had on neurons and Schwann cells. These conclusive results make NVR-Gel enriched with conjugated-GDNF, a desirable scaffold for the reconstruction of severed peripheral nerve.

  13. A theranostic prodrug delivery system based on Pt(IV) conjugated nano-graphene oxide with synergistic effect to enhance the therapeutic efficacy of Pt drug.

    Science.gov (United States)

    Li, Jingwen; Lyv, Zhonglin; Li, Yanli; Liu, Huan; Wang, Jinkui; Zhan, Wenjun; Chen, Hong; Chen, Huabing; Li, Xinming

    2015-05-01

    Due to their high NIR-optical absorption and high specific surface area, graphene oxide and graphene oxide-based nanocomposites have great potential in both drug delivery and photothermal therapy. In the work reported herein we successfully integrate a Pt(IV) complex (c,c,t-[Pt(NH3)2Cl2(OH)2]), PEGylated nano-graphene oxide (PEG-NGO), and a cell apoptosis sensor into a single platform to generate a multifunctional nanocomposite (PEG-NGO-Pt) which shows potential for targeted drug delivery and combined photothermal-chemotherapy under near infrared laser irradiation (NIR), and real-time monitoring of its therapeutic efficacy. Non-invasive imaging using a fluorescent probe immobilized on the GO shows an enhanced therapeutic effect of PEG-NGO-Pt in cancer treatment via apoptosis and cell death. Due to the enhanced cytotoxicity of cisplatin and the highly specific tumor targeting of PEG-NGO-Pt at elevated temperatures, this nanocomposite displays a synergistic effect in improving the therapeutic efficacy of the Pt drug with complete destruction of tumors, no tumor recurrence and minimal systemic toxicity in comparison with chemotherapy or photothermal treatment alone, highlighting the advantageous effects of integrating Pt(IV) with GO for anticancer treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Symmetrized density matrix renormalization group algorithm for low-lying excited states of conjugated carbon systems: Application to 1,12-benzoperylene and polychrysene

    Science.gov (United States)

    Prodhan, Suryoday; Ramasesha, S.

    2018-05-01

    The symmetry adapted density matrix renormalization group (SDMRG) technique has been an efficient method for studying low-lying eigenstates in one- and quasi-one-dimensional electronic systems. However, the SDMRG method had bottlenecks involving the construction of linearly independent symmetry adapted basis states as the symmetry matrices in the DMRG basis were not sparse. We have developed a modified algorithm to overcome this bottleneck. The new method incorporates end-to-end interchange symmetry (C2) , electron-hole symmetry (J ) , and parity or spin-flip symmetry (P ) in these calculations. The one-to-one correspondence between direct-product basis states in the DMRG Hilbert space for these symmetry operations renders the symmetry matrices in the new basis with maximum sparseness, just one nonzero matrix element per row. Using methods similar to those employed in the exact diagonalization technique for Pariser-Parr-Pople (PPP) models, developed in the 1980s, it is possible to construct orthogonal SDMRG basis states while bypassing the slow step of the Gram-Schmidt orthonormalization procedure. The method together with the PPP model which incorporates long-range electronic correlations is employed to study the correlated excited-state spectra of 1,12-benzoperylene and a narrow mixed graphene nanoribbon with a chrysene molecule as the building unit, comprising both zigzag and cove-edge structures.

  15. Synthesis and electrochemical characterization of new optoelectronic materials based on conjugated donor-acceptor system containing oligo-tri(heteroaryl)-1,3,5-triazines

    International Nuclear Information System (INIS)

    Idzik, Krzysztof R.; Rapta, Peter; Cywinski, Piotr J.; Beckert, Rainer; Dunsch, Lothar

    2010-01-01

    A series of novel oligoarylenes based on donor-acceptor system, containing triazine moiety as an electron-transporting central core, have been prepared by electrochemical polymerization. The redox behaviour of poly(2,4,6-tri[p-(2-(3,4-ethylenedioxythienyl))-phenyl]-1,3,5-triazine) was studied by cyclic voltammetry and triple in situ ESR/UV-vis-NIR spectroelectrochemistry to get more details on the type of charge carriers within the film. To obtain desired oligoarylenes, triazine-core monomers possessing various electrochromic side groups have been synthesized by the Stille cross-coupling methodology. The structures have been confirmed by 1 H NMR, 13 C NMR, and elemental analysis. Monomers show good chemical stability in common organic solvents such as chloroform, dichloromethane or toluene and also exhibit excellent thermal stability over wide range of temperatures. Furthermore, their photophysical properties have been established with the use of fluorescence spectroscopy. Electrochemical results accompanied with fluorescence spectroscopy suggest that these derivatives of triazine can be successfully used in the fabrication of organic light-emitting diodes (OLEDs).

  16. Formation of primary sperm conjugates in a haplogyne spider (Caponiidae, Araneae) with remarks on the evolution of sperm conjugation in spiders.

    Science.gov (United States)

    Lipke, Elisabeth; Michalik, Peter

    2012-11-01

    Sperm conjugation, where two or more sperm are physically united, is a rare but widespread pheno-menon across the animal kingdom. One group well known for its different types of sperm conjugation are spiders. Particularly, haplogyne spiders show a high diversity of sperm traits. Besides individual cleistospermia, primary (synspermia) and secondary (coenospermia, "spermatophore") sperm conjugation occurs. However, the evolution of sperm conjugates and sperm is not understood in this group. Here, we look at how sperm are transferred in Caponiidae (Haplogynae) in pursuit of additional information about the evolution of sperm transfer forms in spiders. Additionally, we investigated the male reproductive system and spermatozoa using light- and transmission electron-microscopy and provide a 3D reconstruction of individual as of well as conjugated spermatozoa. Mature spermatozoa are characterized by an extremely elongated, helical nucleus resulting in the longest spider sperm known to date. At the end of spermiogenesis, synspermia are formed by complete fusion of four spermatids. Thus, synspermia might have evolved early within ecribellate Haplogynae. The fused sperm cells are surrounded by a prominent vesicular area. The function of the vesicular area remains still unknown but might be correlated with the capacitation process inside the female. Further phylogenetic and functional implications of the spermatozoa and sperm conjugation are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Andrographolide Induces Autophagic Cell Death and Inhibits Invasion and Metastasis of Human Osteosarcoma Cells in An Autophagy-Dependent Manner

    Directory of Open Access Journals (Sweden)

    Ying Liu

    2017-11-01

    Full Text Available Background/Aims: Osteosarcoma (OS is the most common primary malignant tumor of bone tissue. Although treatment effectiveness has improved, the OS survival rate has fluctuated in recent years. Andrographolide (AG has been reported to have antitumor activity against a variety of tumors. Our aim was to investigate the effects and potential mechanisms of AG in human osteosarcoma. Methods: Cell viability and morphological changes were assessed by MTT and live/dead assays. Apoptosis was detected using Annexin V-FITC/PI double staining, DAPI, and caspase-3 assays. Autophagy was detected with mRFP-GFP-LC3 adenovirus transfection and western blot. Cell migration and invasion were detected by wound healing assay and Transwell® experiments. Results: AG dose-dependently reduced the viability of osteosarcoma cells. No increase in apoptosis was detected in AG-treated human OS MG-63 and U-2OS cells, and the pan-caspase inhibitor z-VAD did not attenuate AG-induced cell death. However, AG induced autophagy by suppressing PI3K/Akt/mTOR and enhancing JNK signaling pathways. 3-MA and Beclin-1 siRNA could reverse the cytotoxic effects of AG. In addition, AG inhibited the invasion and metastasis of OS, and this effect could be reversed with Beclin-1 siRNA. Conclusion: AG inhibits viability and induces autophagic death in OS cells. AG-induced autophagy inhibits the invasion and metastasis of OS.

  18. Tetherin Suppresses Type I Interferon Signaling by Targeting MAVS for NDP52-Mediated Selective Autophagic Degradation in Human Cells.

    Science.gov (United States)

    Jin, Shouheng; Tian, Shuo; Luo, Man; Xie, Weihong; Liu, Tao; Duan, Tianhao; Wu, Yaoxing; Cui, Jun

    2017-10-19

    Tetherin (BST2/CD317) is an interferon-inducible antiviral factor known for its ability to block the release of enveloped viruses from infected cells. Yet its role in type I interferon (IFN) signaling remains poorly defined. Here, we demonstrate that Tetherin is a negative regulator of RIG-I like receptor (RLR)-mediated type I IFN signaling by targeting MAVS. The induction of Tetherin by type I IFN accelerates MAVS degradation via ubiquitin-dependent selective autophagy in human cells. Moreover, Tetherin recruits E3 ubiquitin ligase MARCH8 to catalyze K27-linked ubiquitin chains on MAVS at lysine 7, which serves as a recognition signal for NDP52-dependent autophagic degradation. Taken together, our findings reveal a negative feedback loop of RLR signaling generated by Tetherin-MARCH8-MAVS-NDP52 axis and provide insights into a better understanding of the crosstalk between selective autophagy and optimal deactivation of type I IFN signaling. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Huaier Extract Induces Autophagic Cell Death by Inhibiting the mTOR/S6K Pathway in Breast Cancer Cells.

    Directory of Open Access Journals (Sweden)

    Xiaolong Wang

    Full Text Available Huaier extract is attracting increased attention due to its biological activities, including antitumor, anti-parasite and immunomodulatory effects. Here, we investigated the role of autophagy in Huaier-induced cytotoxicity in MDA-MB-231, MDA-MB-468 and MCF7 breast cancer cells. Huaier treatment inhibited cell viability in all three cell lines and induced various large membranous vacuoles in the cytoplasm. In addition, electron microscopy, MDC staining, accumulated expression of autophagy markers and flow cytometry revealed that Huaier extract triggered autophagy. Inhibition of autophagy attenuated Huaier-induced cell death. Furthermore, Huaier extract inhibited the mammalian target of the rapamycin (mTOR/S6K pathway in breast cancer cells. After implanting MDA-MB-231 cells subcutaneously into the right flank of BALB/c nu/nu mice, Huaier extract induced autophagy and effectively inhibited xenograft tumor growth. This study is the first to show that Huaier-induced cytotoxicity is partially mediated through autophagic cell death in breast cancer cells through suppression of the mTOR/S6K pathway.

  20. Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.

    Science.gov (United States)

    Schiebler, Mark; Brown, Karen; Hegyi, Krisztina; Newton, Sandra M; Renna, Maurizio; Hepburn, Lucy; Klapholz, Catherine; Coulter, Sarah; Obregón-Henao, Andres; Henao Tamayo, Marcela; Basaraba, Randall; Kampmann, Beate; Henry, Katherine M; Burgon, Joseph; Renshaw, Stephen A; Fleming, Angeleen; Kay, Robert R; Anderson, Karen E; Hawkins, Phillip T; Ordway, Diane J; Rubinsztein, David C; Floto, Rodrigo Andres

    2015-02-01

    Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection. © 2014 The Authors. Published under the terms of the CC BY 4.0 license.

  1. Cell survival under nutrient stress is dependent on metabolic conditions regulated by Akt and not by autophagic vacuoles.

    Science.gov (United States)

    Bruno, P; Calastretti, A; Priulla, M; Asnaghi, L; Scarlatti, F; Nicolin, A; Canti, G

    2007-10-01

    Akt activation assists tumor cell survival and promotes resistance to chemotherapy. Here we show that constitutively active Akt (CA-Akt) cells are highly sensitized to cell death induced by nutrient and growth factor deprivation, whereas dominant-negative Akt (DN-Akt) cells have a high rate of survival. The content of autophagosomes in starved CA-Akt cells was high, while DN-Akt cells expressed autophagic vacuoles constitutively, independently of nutrition conditions. Thus Akt down-regulation and downstream events can induce autophagosomes which were not directly determinants of cell death. Biochemical analysis in Akt-mutated cells show that (i) Akt and mTOR proteins were degraded more rapidly than the housekeeping proteins, (ii) mTOR phosphorylation at position Thr(2446) was relatively high in DN-Akt and low in CA-Akt cells, induced by starvation in mock cells only, which suggests reduced autoregulation of these pathways in Akt-mutated cells, (iii) both protein synthesis and protein degradation were significantly higher in starved CA-Akt cells than in starved DN-Akt cells or mock cells. In conclusion, constitutively active Akt, unable to control synthesis and wasting of proteins, accelerates the death of starved cells.

  2. Dopaminergic neuronal loss, reduced neurite complexity and autophagic abnormalities in transgenic mice expressing G2019S mutant LRRK2.

    Directory of Open Access Journals (Sweden)

    David Ramonet

    2011-04-01

    Full Text Available Mutations in the leucine-rich repeat kinase 2 (LRRK2 gene cause late-onset, autosomal dominant familial Parkinson's disease (PD and also contribute to idiopathic PD. LRRK2 mutations represent the most common cause of PD with clinical and neurochemical features that are largely indistinguishable from idiopathic disease. Currently, transgenic mice expressing wild-type or disease-causing mutants of LRRK2 have failed to produce overt neurodegeneration, although abnormalities in nigrostriatal dopaminergic neurotransmission have been observed. Here, we describe the development and characterization of transgenic mice expressing human LRRK2 bearing the familial PD mutations, R1441C and G2019S. Our study demonstrates that expression of G2019S mutant LRRK2 induces the degeneration of nigrostriatal pathway dopaminergic neurons in an age-dependent manner. In addition, we observe autophagic and mitochondrial abnormalities in the brains of aged G2019S LRRK2 mice and markedly reduced neurite complexity of cultured dopaminergic neurons. These new LRRK2 transgenic mice will provide important tools for understanding the mechanism(s through which familial mutations precipitate neuronal degeneration and PD.

  3. Megestrol acetate improves cardiac function in a model of cancer cachexia-induced cardiomyopathy by autophagic modulation.

    Science.gov (United States)

    Musolino, Vincenzo; Palus, Sandra; Tschirner, Anika; Drescher, Cathleen; Gliozzi, Micaela; Carresi, Cristina; Vitale, Cristiana; Muscoli, Carolina; Doehner, Wolfram; von Haehling, Stephan; Anker, Stefan D; Mollace, Vincenzo; Springer, Jochen

    2016-12-01

    Cachexia is a complex metabolic syndrome associated with cancer. One of the features of cachexia is the loss of muscle mass, characterized by an imbalance between protein synthesis and protein degradation. Muscle atrophy is caused by the hyperactivation of some of the main cellular catabolic pathways, including autophagy. Cachexia also affects the cardiac muscle. As a consequence of the atrophy of the heart, cardiac function is impaired and mortality is increased. Anti-cachectic therapy in patients with cancer cachexia is so far limited to nutritional support and anabolic steroids. The use of the appetite stimulant megestrol acetate (MA) has been discussed as a treatment for cachexia. In this study the effects of MA were tested in cachectic tumour-bearing rats (Yoshida AH-130 ascites hepatoma). Rats were treated daily with 100 mg/kg of MA or placebo starting one day after tumour inoculation, and for a period of 16 days. Body weight and body composition were assessed at baseline and at the end of the study. Cardiac function was analysed by echocardiography at baseline and at day 11. Locomotor activity and food intake were assessed before tumour inoculation and at day 11. Autophagic markers were assessed in gastrocnemius muscle and heart by western blot analysis. Treatment with 100 mg/kg/day MA significantly attenuated the loss of body weight (-9 ± 12%, P  cachexia-induced cardiomyopathy.

  4. Calcium(ii)-catalyzed enantioselective conjugate additions of amines.

    Science.gov (United States)

    Uno, Brice E; Dicken, Rachel D; Redfern, Louis R; Stern, Charlotte M; Krzywicki, Greg G; Scheidt, Karl A

    2018-02-14

    The direct enantioselective chiral calcium(ii)·phosphate complex (Ca[CPA] 2 )-catalyzed conjugate addition of unprotected alkyl amines to maleimides was developed. This mild catalytic system represents a significant advance towards the general convergent asymmetric amination of α,β-unsaturated electrophiles, providing medicinally relevant chiral aminosuccinimide products in high yields and enantioselectivities. Furthermore, the catalyst can be reused directly from a previously chromatographed reaction and still maintain both high yield and selectivity.

  5. A possibility for generation of two species of charge carriers along main-chain and side-chains for a π-conjugated polymer

    International Nuclear Information System (INIS)

    Kudo, Yuki; Kawabata, Kohsuke; Goto, Hiromasa

    2013-01-01

    Iodide doping produces charge carriers in π-conjugated polymers. Solitons can be generated in the case of polyacetylene, and polarons in the case of aromatic-type conjugated polymers. We synthesized a conjugated main-chain/side-chain polymer, which consists of polyene in the main-chain and aromatic-type conjugated units in the side-chains. Based on the SSH (Su, Schrieffer, Heeger) theoretical model of solitons in one-dimensional conjugated polymers, we experimentally carried out chemical doping to the main-chain/side-chains conjugated polymer. Generation of the charge carriers was examined by electron spin resonance spectroscopy. This study may lead to realization of a dual doping system of solitons and polarons in π-conjugation expanded to two-dimensional directions in polymers.

  6. Conjugative Plasmid Transfer in Xylella fastidiosa Is Dependent on tra and trb Operon Functions

    OpenAIRE

    Burbank, Lindsey P.; Van Horn, Christopher R.

    2017-01-01

    The insect-transmitted plant pathogen Xylella fastidiosa is capable of efficient horizontal gene transfer (HGT) and recombination. Natural transformation occurs at high rates in X. fastidiosa, but there also is evidence that certain strains of X. fastidiosa carry native plasmids equipped with transfer and mobilization genes, suggesting conjugation as an additional mechanism of HGT in some instances. Two operons, tra and trb, putatively encoding a conjugative type IV secretion system, are foun...

  7. Safety and immunogenicity of meningococcal A and C polysaccharide conjugate vaccine in adults.

    OpenAIRE

    Anderson, E L; Bowers, T; Mink, C M; Kennedy, D J; Belshe, R B; Harakeh, H; Pais, L; Holder, P; Carlone, G M

    1994-01-01

    A meningococcal vaccine containing group A and C polysaccharides conjugated to CRM197 was evaluated in 50 adults. Vaccinees were entered into one of five groups: 30 adults received a single dose of either 22, 11, or 5.5 micrograms of the conjugated A-C vaccine; 10 received an approved meningococcal vaccine; and 10 received saline injections. Local and systemic reactions to vaccines were recorded, and immune responses were determined. The experimental meningococcal vaccine was well tolerated, ...

  8. Novel Aflatoxin Derivatives and Protein Conjugates

    Directory of Open Access Journals (Sweden)

    Reinhard Niessner

    2007-03-01

    Full Text Available Aflatoxins, a group of structurally related mycotoxins, are well known for their toxic and carcinogenic effects in humans and animals. Aflatoxin derivatives and protein conjugates are needed for diverse analytical applications. This work describes a reliable and fast synthesis of novel aflatoxin derivatives, purification by preparative HPLC and characterisation by ESI-MS and one- and two-dimensional NMR. Novel aflatoxin bovine serum albumin conjugates were prepared and characterised by UV absorption and MALDI-MS. These aflatoxin protein conjugates are potentially interesting as immunogens for the generation of aflatoxin selective antibodies with novel specificities.

  9. An Integrated Solution for Performing Thermo-fluid Conjugate Analysis

    Science.gov (United States)

    Kornberg, Oren

    2009-01-01

    A method has been developed which integrates a fluid flow analyzer and a thermal analyzer to produce both steady state and transient results of 1-D, 2-D, and 3-D analysis models. The Generalized Fluid System Simulation Program (GFSSP) is a one dimensional, general purpose fluid analysis code which computes pressures and flow distributions in complex fluid networks. The MSC Systems Improved Numerical Differencing Analyzer (MSC.SINDA) is a one dimensional general purpose thermal analyzer that solves network representations of thermal systems. Both GFSSP and MSC.SINDA have graphical user interfaces which are used to build the respective model and prepare it for analysis. The SINDA/GFSSP Conjugate Integrator (SGCI) is a formbase graphical integration program used to set input parameters for the conjugate analyses and run the models. The contents of this paper describes SGCI and its thermo-fluids conjugate analysis techniques and capabilities by presenting results from some example models including the cryogenic chill down of a copper pipe, a bar between two walls in a fluid stream, and a solid plate creating a phase change in a flowing fluid.

  10. Polyvinyl alcohol composite nanofibres containing conjugated levofloxacin-chitosan for controlled drug release

    International Nuclear Information System (INIS)

    Jalvandi, Javid; White, Max; Gao, Yuan; Truong, Yen Bach; Padhye, Rajiv; Kyratzis, Ilias Louis

    2017-01-01

    A range of biodegradable drug-nanofibres composite mats have been reported as drug delivery systems. However, their main disadvantage is the rapid release of the drug immediately after application. This paper reports an improved system based on the incorporation of drug conjugated-chitosan into polyvinyl alcohol (PVA) nanofibers. The results showed that controlled release of levofloxacin (LVF) could be achieved by covalently binding LVF to low molecular weight chitosan (CS) via a cleavable amide bond and then blending the conjugated CS with polyvinyl alcohol (PVA) nanofibres prior to electrospinning. PVA/LVF and PVA-CS/LVF nanofibres were fabricated as controls. The conjugated CS-LVF was characterized by FTIR, DSC, TGA and 1 H NMR. Scanning electron microscopy (SEM) showed that the blended CS-PVA nanofibres had a reduced fibre diameter compared to the controls. Drug release profiles showed that burst release was decreased from 90% in the control PVA/LVF electrospun mats to 27% in the PVA/conjugated CS-LVF mats after 8 h in phosphate buffer at 37 °C. This slower release is due to the cleavable bond between LVF and CS that slowly hydrolysed over time at neutral pH. The results indicate that conjugation of the drug to the polymer backbone is an effective way of minimizing burst release behaviour and achieving sustained release of the drug, LVF. - Highlights: • A novel drug delivery system for controlled release of drug was designed. • Composite PVA/conjugated CS-LVF nanofibres was fabricated by electrospinning. • Conjugated chitosan and composite nanofibres were characterized by various techniques. • Release profiles of drug were significantly improved in composite nanofibres containing drug conjugated chitosan.

  11. Polyvinyl alcohol composite nanofibres containing conjugated levofloxacin-chitosan for controlled drug release

    Energy Technology Data Exchange (ETDEWEB)

    Jalvandi, Javid, E-mail: Javid.jlv@gmail.com [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia); School of Fashion and Textiles, College of Design and Social Context, RMIT University, 25 Dawson Street, Brunswick, Victoria 3056 (Australia); White, Max, E-mail: tamrak@bigpond.com [School of Fashion and Textiles, College of Design and Social Context, RMIT University, 25 Dawson Street, Brunswick, Victoria 3056 (Australia); Gao, Yuan, E-mail: Yuan.Gao@csiro.au [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia); Truong, Yen Bach, E-mail: Yen.truong@csiro.au [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia); Padhye, Rajiv, E-mail: rajiv.padhye@rmit.edu.au [School of Fashion and Textiles, College of Design and Social Context, RMIT University, 25 Dawson Street, Brunswick, Victoria 3056 (Australia); Kyratzis, Ilias Louis, E-mail: Louis.kyratzis@csiro.au [CSIRO, Manufacturing Flagship, Bayview Ave, Clayton, Victoria 3168 (Australia)

    2017-04-01

    A range of biodegradable drug-nanofibres composite mats have been reported as drug delivery systems. However, their main disadvantage is the rapid release of the drug immediately after application. This paper reports an improved system based on the incorporation of drug conjugated-chitosan into polyvinyl alcohol (PVA) nanofibers. The results showed that controlled release of levofloxacin (LVF) could be achieved by covalently binding LVF to low molecular weight chitosan (CS) via a cleavable amide bond and then blending the conjugated CS with polyvinyl alcohol (PVA) nanofibres prior to electrospinning. PVA/LVF and PVA-CS/LVF nanofibres were fabricated as controls. The conjugated CS-LVF was characterized by FTIR, DSC, TGA and {sup 1}H NMR. Scanning electron microscopy (SEM) showed that the blended CS-PVA nanofibres had a reduced fibre diameter compared to the controls. Drug release profiles showed that burst release was decreased from 90% in the control PVA/LVF electrospun mats to 27% in the PVA/conjugated CS-LVF mats after 8 h in phosphate buffer at 37 °C. This slower release is due to the cleavable bond between LVF and CS that slowly hydrolysed over time at neutral pH. The results indicate that conjugation of the drug to the polymer backbone is an effective way of minimizing burst release behaviour and achieving sustained release of the drug, LVF. - Highlights: • A novel drug delivery system for controlled release of drug was designed. • Composite PVA/conjugated CS-LVF nanofibres was fabricated by electrospinning. • Conjugated chitosan and composite nanofibres were characterized by various techniques. • Release profiles of drug were significantly improved in composite nanofibres containing drug conjugated chitosan.

  12. Evaluation of iodovinyl antibody conjugates: Comparison with a p-iodobenzoyl conjugate and direct radioiodination

    International Nuclear Information System (INIS)

    Hadley, S.W.; Wilbur, D.S.

    1990-01-01

    The preparations and conjugations of 2,3,5,6-tetrafluorophenyl 5-[125I/131I]iodo-4-pentenoate (7a) and 2,3,5,6-tetrafluorophenyl 3,3-dimethyl-5-[125I/131I]iodo-4-pentenoate (7b) to monoclonal antibodies are reported. Reagents 7a and 7b were prepared in high radiochemical yield by iododestannylation of their corresponding 5-tri-n-butylstannyl precursors. Radioiodinated antibody conjugates were prepared by reaction of 7a or 7b with the protein at basic pH. Evaluation of these conjugates by several in vitro procedures demonstrated that the radiolabel was attached to the antibody in a stable manner and that the conjugates maintained immunoreactivity. Comparative dual-isotope biodistribution studies of a monoclonal antibody Fab fragment conjugate of 7a and 7b with the same Fab fragment labeled with N-succinimidyl p-[131I]iodobenzoate (PIB, p-iodobenzoate, 2) or directly radioiodinated have been carried out in tumor-bearing nude mice. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 2 demonstrated that the biodistributions were similar in most organs, except the neck tissue (thyroid-containing) and the stomach, which contained substantially increased levels of the 7a label. Coinjection of the Fab conjugate of 7a with the Fab fragment radioiodinated by using the chloramine-T method demonstrated that the biodistributions were remarkably similar, suggesting roughly equivalent in vivo deiodination of these labeled antibody fragments. Coinjection of the Fab conjugate of 7a with the Fab conjugate of 7b indicated that there was ∼ a 2-fold reduction in the amount of in vivo deiodination of the 7b conjugate as compared to the 7a conjugate

  13. Reductive nanocomplex encapsulation of cRGD-siRNA conjugates for enhanced targeting to cancer cells

    Directory of Open Access Journals (Sweden)

    Zhou Z

    2017-10-01

    Full Text Available Zhaoxiu Zhou,* Shuang Liu,* Yanfen Zhang, Xiantao Yang, Yuan Ma, Zhu Guan, Yun Wu, Lihe Zhang, Zhenjun Yang State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, People’s Republic of China *These authors contributed equally to this work Abstract: In this study, through covalent conjugation and lipid material entrapment, a combined modification strategy was established for effective delivery of small interfering RNA (siRNA. Single strands of siRNA targeting to BRAFV600E gene (siMB3 conjugated with cRGD peptide at 3'-terminus or 5'-terminus via cleavable disulfide bond was synthesized and then annealed with corresponding strands to obtain single and bis-cRGD-siRNA conjugates. A cationic lipid material (CLD developed by our laboratory was mixed with the conjugates to generate nanocomplexes; their uniformity and electrical property were revealed by particle size and zeta potential measurement. Compared with CLD/siBraf, CLD/cRGD-siBraf achieved higher cell uptake and more excellent tumor-targeting ability, especially 21 (sense-5′/antisense-3″-cRGD-congjugate nanocomplex. Moreover, they can regulate multiple pathways to varying degree and reduce acidification of endosome. Compared with the gene silencing of different conjugates, single or bis-cRGD-conjugated siRNA showed little differences except 22 (5/5 which cRGD was conjugated at 5'-terminus of antisense strand and sense strand. However bis-cRGD conjugate 21 nanocomplex exhibited better specific target gene silencing at multiple time points. Furthermore, the serum stabilities of the bis-cRGD conjugates were higher than those of the single-cRGD conjugates. In conclusion, all these data suggested that CLD/bis-conjugates, especially CLD/21, can be an effective system for delivery of siRNA to target BRAFV600E gene for therapy of melanoma. Keywords: cRGD-siRNA conjugates, cationic lipids, targeting, silencing, intracellular pathways

  14. Conjugate descent formulation of backpropagation error in ...

    African Journals Online (AJOL)

    nique of backpropagation was popularized in a paper by Rumelhart, et al. ... the training of a multilayer neural network using a gradient descent approach applied to a .... superior convergence of the conjugate descent method over a standard ...

  15. All solid-state SBS phase conjugate mirror

    Science.gov (United States)

    Dane, C.B.; Hackel, L.A.

    1999-03-09

    A stimulated Brillouin scattering (SBS) phase conjugate laser mirror uses a solid-state nonlinear gain medium instead of the conventional liquid or high pressure gas medium. The concept has been effectively demonstrated using common optical-grade fused silica. An energy threshold of 2.5 mJ and a slope efficiency of over 90% were achieved, resulting in an overall energy reflectivity of >80% for 15 ns, 1 um laser pulses. The use of solid-state materials is enabled by a multi-pass resonant architecture which suppresses transient fluctuations that would otherwise result in damage to the SBS medium. This all solid state phase conjugator is safer, more reliable, and more easily manufactured than prior art designs. It allows nonlinear wavefront correction to be implemented in industrial and defense laser systems whose operating environments would preclude the introduction of potentially hazardous liquids or high pressure gases. 8 figs.

  16. Application of Conjugate Gradient methods to tidal simulation

    Science.gov (United States)

    Barragy, E.; Carey, G.F.; Walters, R.A.

    1993-01-01

    A harmonic decomposition technique is applied to the shallow water equations to yield a complex, nonsymmetric, nonlinear, Helmholtz type problem for the sea surface and an accompanying complex, nonlinear diagonal problem for the velocities. The equation for the sea surface is linearized using successive approximation and then discretized with linear, triangular finite elements. The study focuses on applying iterative methods to solve the resulting complex linear systems. The comparative evaluation includes both standard iterative methods for the real subsystems and complex versions of the well known Bi-Conjugate Gradient and Bi-Conjugate Gradient Squared methods. Several Incomplete LU type preconditioners are discussed, and the effects of node ordering, rejection strategy, domain geometry and Coriolis parameter (affecting asymmetry) are investigated. Implementation details for the complex case are discussed. Performance studies are presented and comparisons made with a frontal solver. ?? 1993.

  17. Conjugate heat transfer of laminar film condensation along a horizontal plate

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Euk Soo [Pusan National Univesity, Busan (Korea, Republic of)

    2006-03-15

    This paper proposes appropriate conjugate parameters and dimensionless temperatures to analysis the conjugate problem of heat conduction in solid wall coupled with laminar film condensation flow adjacent to horizontal flat plate. An efficient methods for some fluids are proposed for its solution. The momentum and energy balance equations are reduced to a nonlinear system of ordinary differential equations with four parameters: the Prandtl number, Pr, Modified Jacob number, Ja{sup *}/Pr, defined by an overall temperature difference, a property ratio {radical}{rho}{sub {iota}}{mu}{sub {iota}} {radical}{rho}{sub {upsilon}}{mu}{sub {upsilon}} and the conjugate parameter {zeta}. The obtained similarity solution reveals the effect of the conjugate parameter, and the results are compared with the simplified solution. The variations of the heat transfer rates as well as the interface temperature and frictions along the plate are shown explicitly.

  18. Diffeomorphisms Holder conjugate to Anosov diffeomorphisms

    OpenAIRE

    Gogolev, Andrey

    2008-01-01

    We show by means of a counterexample that a $C^{1+Lip}$ diffeomorphism Holder conjugate to an Anosov diffeomorphism is not necessarily Anosov. The counterexample can bear higher smoothness up to $C^3$. Also we include a result from the 2006 Ph.D. thesis of T. Fisher: a $C^{1+Lip}$ diffeomorphism Holder conjugate to an Anosov diffeomorphism is Anosov itself provided that Holder exponents of the conjugacy and its inverse are sufficiently large.

  19. Rapid modification of retroviruses using lipid conjugates

    International Nuclear Information System (INIS)

    Mukherjee, Nimisha G; Le Doux, Joseph M; Andrew Lyon, L

    2009-01-01

    Methods are needed to manipulate natural nanoparticles. Viruses are particularly interesting because they can act as therapeutic cellular delivery agents. Here we examine a new method for rapidly modifying retroviruses that uses lipid conjugates composed of a lipid anchor (1,2-distearoyl-sn-glycero-3-phosphoethanolamine), a polyethylene glycol chain, and biotin. The conjugates rapidly and stably modified retroviruses and enabled them to bind streptavidin. The implication of this work for modifying viruses for gene therapy and vaccination protocols is discussed.

  20. A pH-responsive carboxymethyl dextran-based conjugate as a carrier of docetaxel for cancer therapy.

    Science.gov (United States)

    Han, Hwa Seung; Lee, Minchang; An, Jae Yoon; Son, Soyoung; Ko, Hyewon; Lee, Hansang; Chae, Yee Soo; Kang, Young Mo; Park, Jae Hyung

    2016-05-01

    Although docetaxel is available for the treatment of various cancers, its clinical applications are limited by its poor water solubility and toxicity to normal cells, resulting in severe adverse effects. In this study, we synthesized a polymeric conjugate with an acid-labile ester linkage, consisting of carboxymethyl dextran (CMD) and docetaxel (DTX), as a potential anticancer drug delivery system. The conjugate exhibited sustained release of DTX in physiological buffer (pH 7.4), whereas its release rate increased remarkably under mildly acidic conditions (pH < 6.5), mimicking the intracellular environment. Cytotoxicity tests conducted in vitro demonstrated that the conjugate exhibited much higher toxicity to cancer cells under mildly acidic conditions than at physiological buffer (pH 7.4). These results implied that the ester linkage in the conjugate allowed for selective release of biologically active DTX under mildly acidic conditions. The in vivo biodistribution of a Cy5.5-labeled conjugate was observed using the noninvasive optical imaging technique after its systemic administration into tumor-bearing mice. The conjugate was effectively accumulated into the tumor site, which may have been because of an enhanced permeability and retention effect. In addition, in vivo antitumor efficacy of the conjugate was significantly higher than that of free DTX. Overall, the CMD-based conjugate might have promising potential as a carrier of DTX for cancer therapy. © 2015 Wiley Periodicals, Inc.

  1. Calpain Determines the Propensity of Adult Hippocampal Neural Stem Cells to Autophagic Cell Death Following Insulin Withdrawal.

    Science.gov (United States)

    Chung, Kyung Min; Park, Hyunhee; Jung, Seonghee; Ha, Shinwon; Yoo, Seung-Jun; Woo, Hanwoong; Lee, Hyang Ju; Kim, Seong Who; Kim, Eun-Kyoung; Moon, Cheil; Yu, Seong-Woon

    2015-10-01

    Programmed cell death (PCD) has significant effects on the function of neural stem cells (NSCs) during brain development and degeneration. We have previously reported that adult rat hippocampal neural stem (HCN) cells underwent autophagic cell death (ACD) rather than apoptosis following insulin withdrawal despite their intact apoptotic capabilities. Here, we report a switch in the mode of cell death in HCN cells with calpain as a critical determinant. In HCN cells, calpain 1 expression was barely detectable while calpain 2 was predominant. Inhibition of calpain in insulin-deprived HCN cells further augmented ACD. In contrast, expression of calpain 1 switched ACD to apoptosis. The proteasome inhibitor lactacystin blocked calpain 2 degradation and elevated the intracellular Ca(2+) concentration. In combination, these effects potentiated calpain activity and converted the mode of cell death to apoptosis. Our results indicate that low calpain activity, due to absence of calpain 1 and degradation of calpain 2, results in a preference for ACD over apoptosis in insulin-deprived HCN cells. On the other hand, conditions leading to high calpain activity completely switch the mode of cell death to apoptosis. This is the first report on the PCD mode switching mechanism in NSCs. The dynamic change in calpain activity through the proteasome-mediated modulation of the calpain and intracellular Ca(2+) levels may be the critical contributor to the demise of NSCs. Our findings provide a novel insight into the complex mechanisms interconnecting autophagy and apoptosis and their roles in the regulation of NSC death. © 2015 AlphaMed Press.

  2. Update on the use of meningococcal serogroup C CRM₁₉₇-conjugate vaccine (Meningitec) against meningitis.

    Science.gov (United States)

    Badahdah, Al-Mamoon; Rashid, Harunor; Khatami, Ameneh

    2016-01-01

    Meningitec is a CRM197-conjugated meningococcal serogroup C (MenC) vaccine, first licensed in 1999. It has been used as a primary and booster vaccine in infants, toddlers, older children and adults, and has been shown to be immunogenic and well-tolerated in all age groups, including premature infants. Vaccine effectiveness has been demonstrated using combined data on all three licensed MenC conjugate vaccines. Evidence from clinical trials, however, suggests that the different MenC conjugate vaccines behave differently with respect to the induction and persistence of bactericidal antibody and generation of immune memory. It appears that Meningitec has a less favorable immunologic profile compared particularly to tetanus toxoid (TT) MenC conjugate vaccines. Data from comparative trials have raised interesting questions on priming of the immune system by conjugate vaccines, particularly in infants. The results from these and other studies are reviewed here with specific focus on Meningitec.

  3. Effect of different hapten-carrier conjugation ratios and molecular orientations on antibody affinity against a peptide antigen

    DEFF Research Database (Denmark)

    Pedersen, M. K.; Sørensen, Nanna Skall; Heegaard, Peter M. H.

    2006-01-01

    -based assay systems and in deciding whether a vaccine-induced antibody response will be protective. With ovalbumin as a carrier protein and a peptide (7.2NY) representing a 19 ammo acid sequence from the E. coli-derived Verotoxin 2e as a model hapten we investigated whether it was possible to influence...... ten dines at two-weeks intervals with low doses of the eight conjugates, Blood samples collected between each immunisation were analysed by ELISA for specific antibody titres and relative affinities. With both types of conjugations, the anti-peptide antibody titres increased in response to increasing...... for terminal conjugation. Thus, it appears that the molar ratio of a peptide and its carrier may affect the resulting antibody affinities, and that a conjugation ratio between a terminally Conjugated peptide and its carrier approaching one will result in relatively high antibody affinities. Furthermore...

  4. In vitro results of conjugation of arabinagalactan and pegulated avidin

    International Nuclear Information System (INIS)

    Lichtenstein, L.; Salehi, N.; Doukarellis, C.

    1998-01-01

    Full text: The principles of avidin - biotin tumor targeting system were described at the Society of Nuclear Medicine in 1995. The preparation and use of the pegulated avidin to prolong circulation of avidin and therefore its uptake into tumour was reported in 1997. The biodistribution of radioactivity, tumour to blood, liver and bone T: B1 = 6.3, T: Li - 0.32 and T: B - 10.9 showed that the pegulation ( PEG) of avidin increased its circulation time which resulted in the high activity in the blood circulation and that the Dextran - Biotin conjugate was used to aggregate the PEG - Avidin, failed to facilitate its desired clearance out of the blood pool. Aim: We attempted to couple the 9 KDa fragment of 37 KDa polysaccharide arabinogalactan ( AG 37 KDa) with pegulated avidin to facilitate its hepatic clearance and thus increase the uptake of radiolabelled Tc - 99m - DTPA - Biocytinamide in all tissues including tumour. Method: AG (9 KDa) fragment was isolated from AG (37 KDa) by autoclaving at 121deg C and separated using a 10 KDa centricon ultrafiltration membrane. The average molecular weight was determined by HPLC at UV absorbance 280 nm. The AG 9kDa sample was oxidised by adding NaIO4, 30 minutes after incubation the solution was purified and coupled to Biotin - Hydrazide at (1:1) molar ratio, 2hrs after incubation, the coupled agent was radiolabelled with Tc-99m. The instant thin - layer chromatography (ITLC strips), with M.E.K and N.S. as eluants showed a LE = 91 %. The radiolabelled product was coupled to pegulated avidin at (1:1) for 1 hr at RT. The conjugated agent was separated by using 50 KDa ultrafiltration membrane. Results: > 95 % of AG - Biotin - Tc -99m- pegulated avidin remained unfiltered hence conjugated Conclusion: The results obtained from in vitro conjugation is encouraging and will be experimented for in vivo studies

  5. Folate coupled poly(ethyleneglycol) conjugates of anionic poly(amidoamine) dendrimer for inflammatory tissue specific drug delivery.

    Science.gov (United States)

    Chandrasekar, Durairaj; Sistla, Ramakrishna; Ahmad, Farhan J; Khar, Roop K; Diwan, Prakash V

    2007-07-01

    Folate receptor is overexpressed on the activated (but not quiescent) macrophages in both animal models and human patients with naturally occurring rheumatoid arthritis. The aim of this study was to prepare folate targeted poly(ethylene glycol) (PEG) conjugates of anionic dendrimer (G3.5 PAMAM) as targeted drug delivery systems to inflammation and to investigate its biodistribution pattern in arthritic rats. Folate-PEG-PAMAM conjugates, with different degrees of substitution were synthesized by a two-step reaction through a carbodiimide-mediated coupling reaction and loaded with indomethacin. Folate-PEG conjugation increased the drug loading efficiency by 10- to 20-fold and the in vitro release profile indicated controlled release of drug. The plasma pharmacokinetic parameters indicated an increased AUC, circulatory half-life and mean residence time for the folate-PEG conjugates. The tissue distribution studies revealed significantly lesser uptake by stomach for the folate-PEG conjugates, thereby limiting gastric-related side effect. The time-averaged relative drug exposure (r(e)) of the drug in paw for the folate-PEG conjugates ranged from 1.81 to 2.37. The overall drug targeting efficiency (T(e)) was highest for folate-PEG conjugate (3.44) when compared to native dendrimer (1.72). The folate-PEG-PAMAM conjugates are the ideal choice for targeted delivery of antiarthritic drugs to inflammation with reduced side-effects and higher targeting efficiency. Copyright 2007 Wiley Periodicals, Inc.

  6. Mobility of the native Bacillus subtilis conjugative plasmid pLS20 is regulated by intercellular signaling.

    Science.gov (United States)

    Singh, Praveen K; Ramachandran, Gayetri; Ramos-Ruiz, Ricardo; Peiró-Pastor, Ramón; Abia, David; Wu, Ling J; Meijer, Wilfried J J

    2013-10-01

    Horizontal gene transfer mediated by plasmid conjugation plays a significant role in the evolution of bacterial species, as well as in the dissemination of antibiotic resistance and pathogenicity determinants. Characterization of their regulation is important for gaining insights into these features. Relatively little is known about how conjugation of Gram-positive plasmids is regulated. We have characterized conjugation of the native Bacillus subtilis plasmid pLS20. Contrary to the enterococcal plasmids, conjugation of pLS20 is not activated by recipient-produced pheromones but by pLS20-encoded proteins that regulate expression of the conjugation genes. We show that conjugation is kept in the default "OFF" state and identified the master repressor responsible for this. Activation of the conjugation genes requires relief of repression, which is mediated by an anti-repressor that belongs to the Rap family of proteins. Using both RNA sequencing methodology and genetic approaches, we have determined the regulatory effects of the repressor and anti-repressor on expression of the pLS20 genes. We also show that the activity of the anti-repressor is in turn regulated by an intercellular signaling peptide. Ultimately, this peptide dictates the timing of conjugation. The implications of this regulatory mechanism and comparison with other mobile systems are discussed.

  7. Micelle-like nanoassemblies based on polymer-drug conjugates as an emerging platform for drug delivery.

    Science.gov (United States)

    Liu, Zhihong; Wang, Yutao; Zhang, Na

    2012-07-01

    During the past decades, polymer-drug conjugates are one of the hottest topics in novel drug development fields. Amphiphilic polymer-drug conjugates in aqueous solution could form micelles or micelle-like nanoassemblies. Compared with polymer-drug conjugates and the micelles into which drugs are physically entrapped, micelles or micelle-like nanoassemblies based on polymer-drug conjugates bring several additional advantages, including increased drug-loading capacity, enhanced intracellular uptake, reduced systemic toxicity, and improved therapeutic efficacy. This review focuses on recent progress achieved in the research field of micelles or micelle-like nanoassemblies based on polymer-drug conjugates. Firstly, properties of polymers, drugs, and linkers which could be used to build polymer-drug conjugate micelles or micelle-like nanoassemblies are summarized. Then, the characterization methods are described. Finally, the drug-targeting mechanisms are discussed. Micelles or micelle-like nanoassemblies based on polymer-drug conjugates as an emerging platform have the potential to achieve medical treatments with enhanced therapeutic effect. The application of micelles or micelle-like nanoassemblies based on polymer-drug conjugates may give new life to old active compounds abandoned due to their low solubility problems. For clinical application, there is a need to further optimize the properties of the polymer, drug, and linker.

  8. Autophagic effects of Hibiscus sabdariffa leaf polyphenols and epicatechin gallate (ECG) against oxidized LDL-induced injury of human endothelial cells.

    Science.gov (United States)

    Chen, Jing-Hsien; Lee, Ming-Shih; Wang, Chi-Ping; Hsu, Cheng-Chin; Lin, Hui-Hsuan

    2017-08-01

    Oxidized low-density lipoprotein (ox-LDL) contributes to the pathogenesis of atherosclerosis by promoting vascular endothelial cell injury. Hibiscus sabdariffa leaf polyphenols (HLP), rich in flavonoids, have been shown to possess antioxidant and antiatherosclerotic activities. In this study, we examined the protective role of HLP and its main compound (-)-epicatechin gallate (ECG) in human umbilical vein endothelial cells (HUVECs) exposed to ox-LDL in vitro. In a model of ox-LDL-impaired HUVECs, assessments of cell viability, cytotoxicity, cell proliferation, apoptosis, and autophagy were detected. To highlight the mechanisms of the antiapoptotic effects of HLP and ECG, the expressions of molecular proteins were measured by Western blotting, real-time PCR, and so on. HLP or ECG improved the survival of HUVECs from ox-LDL-induced viability loss. In addition, HLP or ECG showed potential in reducing ox-LDL-dependent apoptosis. Next, the ox-LDL-induced formation of acidic vesicular organelles and upregulation of the autophagy-related genes were increased by HLP or ECG. The HLP-triggered autophagic flux was further confirmed by increasing the LC3-II level under the pretreatment of an autophagy inhibitor chloroquine. Molecular data indicated the autophagic effect of HLP or ECG might be mediated via class III PI3K/Beclin-1 and PTEN/class I PI3K/Akt cascade signaling, as demonstrated by the usage of a class III PI3K inhibitor 3-methyladenine (3-MA) and a PTEN inhibitor SF1670. Our data imply that ECG-enriched HLP upregulates the autophagic pathway, which in turn led to reduce ox-LDL-induced HUVECs injury and apoptosis and provide a new mechanism for its antiatherosclerotic activity.

  9. Targeted delivery of polyamidoamine-paclitaxel conjugate functionalized with anti-human epidermal growth factor receptor 2 trastuzumab

    Directory of Open Access Journals (Sweden)

    Ma P

    2015-03-01

    Full Text Available Pengkai Ma,1 Xuemei Zhang,1 Ling Ni,2 Jinming Li,2 Fengpu Zhang,1 Zheng Wang,1 Shengnan Lian,1 Kaoxiang Sun1 1School of Pharmacy, Yantai University, Yantai, Shandong Province, People’s Republic of China; 2State Key Laboratory of Long-acting and Targeting Drug Delivery System, Yantai, Shandong Province, People’s Republic of China Background: Antibody-dendrimer conjugates have the potential to improve the targeting and release of chemotherapeutic drugs at the tumor site while reducing adverse side effects caused by drug accumulation in healthy tissues. In this study, trastuzumab (TMAB, which binds to human epidermal growth factor receptor 2 (HER2, was used as a targeting agent in a TMAB-polyamidoamine (PAMAM conjugate carrying paclitaxel (PTX specifically to cells overexpressing HER2. Methods: TMAB was covalently linked to a PAMAM dendrimer via bifunctional polyethylene glycol (PEG. PTX was conjugated to PAMAM using succinic anhydride as a cross-linker, yielding TMAB-PEG-PAMAM-PTX. Dynamic light scattering and transmission electron microscopy were used to characterize the conjugates. The cellular uptake and in vivo biodistribution were studied by fluorescence microscopy, flow cytometry, and Carestream In Vivo FX, respectively. Results: Nuclear magnetic resonance spectroscopy demonstrated that PEG, PTX, fluorescein isothiocyanate, and cyanine7 were conjugated to PAMAM. Ultraviolet-visible spectroscopy and sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated that TMAB was conjugated to PEG-PAMAM. Dynamic light scattering and transmission electron microscopy measurements revealed that the different conjugates ranged in size between 10 and 35 nm and had a spherical shape. In vitro cellular uptake demonstrated that the TMAB-conjugated PAMAM was taken up by HER2-overexpressing BT474 cells more efficiently than MCF-7 cells that expressed lower levels of HER2. Co-localization experiments indicated that TMAB-conjugated PAMAM was

  10. Identification of a Novel Conjugative Plasmid in Mycobacteria That Requires Both Type IV and Type VII Secretion

    KAUST Repository

    Ummels, R.

    2014-09-23

    Conjugative plasmids have been identified in a wide variety of different bacteria, ranging from proteobacteria to firmicutes, and conjugation is one of the most efficient routes for horizontal gene transfer. The most widespread mechanism of plasmid conjugation relies on different variants of the type IV secretion pathway. Here, we describe the identification of a novel type of conjugative plasmid that seems to be unique for mycobacteria. Interestingly, while this plasmid is efficiently exchanged between different species of slow-growing mycobacteria, including Mycobacterium tuberculosis, it could not be transferred to any of the fast-growing mycobacteria tested. Genetic analysis of the conjugative plasmid showed the presence of a locus containing homologues of three type IV secretion system components and a relaxase. In addition, a new type VII secretion locus was present. Using transposon insertion mutagenesis, we show that in fact both these secretion systems are essential for conjugation, indicating that this plasmid represents a new class of conjugative plasmids requiring two secretion machineries. This plasmid could form a useful new tool to exchange or introduce DNA in slow-growing mycobacteria. IMPORTANCE: Conjugative plasmids play an important role in horizontal gene transfer between different bacteria and, as such, in their adaptation and evolution. This effect is most obvious in the spread of antibiotic resistance genes. Thus far, conjugation of natural plasmids has been described only rarely for mycobacterial species. In fact, it is generally accepted that M. tuberculosis does not show any recent sign of horizontal gene transfer. In this study, we describe the identification of a new widespread conjugative plasmid that can also be efficiently transferred to M. tuberculosis. This plasmid therefore poses both a threat and an opportunity. The threat is that, through the acquisition of antibiotic resistance markers, this plasmid could start a rapid spread of

  11. Program generator for the Incomplete Cholesky Conjugate Gradient (ICCG) method

    International Nuclear Information System (INIS)

    Kuo-Petravic, G.; Petravic, M.

    1978-04-01

    The Incomplete Cholesky Conjugate Gradient (ICCG) method has been found very effective for the solution of sparse systems of linear equations. Its implementation on a computer, however, requires a considerable amount of careful coding to achieve good machine efficiency. Furthermore, the resulting code is necessarily inflexible and cannot be easily adapted to different problems. We present in this paper a code generator GENIC which, given a small amount of information concerning the sparsity pattern and size of the system of equations, generates a solver package. This package, called SOLIC, is tailor made for a particular problem and can be easily incorporated into any user program

  12. Parallel preconditioned conjugate gradient algorithm applied to neutron diffusion problem

    International Nuclear Information System (INIS)

    Majumdar, A.; Martin, W.R.

    1992-01-01

    Numerical solution of the neutron diffusion problem requires solving a linear system of equations such as Ax = b, where A is an n x n symmetric positive definite (SPD) matrix; x and b are vectors with n components. The preconditioned conjugate gradient (PCG) algorithm is an efficient iterative method for solving such a linear system of equations. In this paper, the authors describe the implementation of a parallel PCG algorithm on a shared memory machine (BBN TC2000) and on a distributed workstation (IBM RS6000) environment created by the parallel virtual machine parallelization software

  13. Rapamycin Influences the Efficiency of Fertilization and Development in the Mouse: A Role for Autophagic Activation

    Directory of Open Access Journals (Sweden)

    Geun-Kyung Lee

    2016-08-01

    Full Text Available The mammalian target of rapamycin (mTOR regulates cellular processes such as cell growth, metabolism, transcription, translation, and autophagy. Rapamycin is a selective inhibitor of mTOR, and induces autophagy in various systems. Autophagy contributes to clearance and recycling of macromolecules and organelles in response to stress. We previously reported that vitrified-warmed mouse oocytes show acute increases in autophagy during warming, and suggested that it is a natural response to cold stress. In this follow-up study, we examined whether the modulation of autophagy influences survival, fertilization, and developmental rates of vitrified-warmed mouse oocytes. We used rapamycin to enhance autophagy in metaphase II (MII oocytes before and after vitrification. The oocytes were then subjected to in vitro fertilization (IVF. The fertilization and developmental rates of vitrified-warmed oocytes after rapamycin treatment were significantly lower than those for control groups. Modulation of autophagy with rapamycin treatment shows that rapamycin-induced autophagy exerts a negative influence on fertilization and development of vitrified-warmed oocytes.

  14. Analytical characterization of polymer-drug conjugates

    International Nuclear Information System (INIS)

    Rizzo, V.; Gigli, M.; Pinciroli, V.

    1998-01-01

    A few polymeric conjugates of antitumor drugs have been recently developed in view of possible therapeutic advantages: solubilization of sparingly soluble drugs in water, improvement of therapeutic index, organ targeting through a second chemical species bound to the same polymeric chain. In this article it's described the analytical approach used in the characterization of the conjugates for chemical identity, purity and strength of the contained active ingredient. The techniques are: high field NMR and size exclusion chromatography with non-aqueous mobile phase for identity; selective hydrolysis and HPLC for strength and purity. A complete and reliable picture is thus obtained both for qualitative and for quantitative aspects. This is an important step forward in the direction of further development and marketing of polymer-drug conjugates [it

  15. Nonlinear conjugate gradient methods in micromagnetics

    Directory of Open Access Journals (Sweden)

    J. Fischbacher

    2017-04-01

    Full Text Available Conjugate gradient methods for energy minimization in micromagnetics are compared. The comparison of analytic results with numerical simulation shows that standard conjugate gradient method may fail to produce correct results. A method that restricts the step length in the line search is introduced, in order to avoid this problem. When the step length in the line search is controlled, conjugate gradient techniques are a fast and reliable way to compute the hysteresis properties of permanent magnets. The method is applied to investigate demagnetizing effects in NdFe12 based permanent magnets. The reduction of the coercive field by demagnetizing effects is μ0ΔH = 1.4 T at 450 K.

  16. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Science.gov (United States)

    Miller, Jacqueline M.; Mesaros, Narcisa; Van Der Wielen, Marie; Baine, Yaela

    2011-01-01

    Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT) designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles. PMID:21991444

  17. Conjugate Meningococcal Vaccines Development: GSK Biologicals Experience

    Directory of Open Access Journals (Sweden)

    Jacqueline M. Miller

    2011-01-01

    Full Text Available Meningococcal diseases are serious threats to global health, and new vaccines specifically tailored to meet the age-related needs of various geographical areas are required. This paper focuses on the meningococcal conjugate vaccines developed by GSK Biologicals. Two combined conjugate vaccines were developed to help protect infants and young children in countries where the incidence of meningococcal serogroup C or serogroup C and Y disease is important: Hib-MenC-TT vaccine, which offers protection against Haemophilus influenzae type b and Neisseria meningitidis serogroup C diseases, is approved in several countries; and Hib-MenCY-TT vaccine, which adds N. meningitidis serogroup Y antigen, is currently in the final stages of development. Additionally, a tetravalent conjugate vaccine (MenACWY-TT designed to help protect against four meningococcal serogroups is presently being evaluated for global use in all age groups. All of these vaccines were shown to be highly immunogenic and to have clinically acceptable safety profiles.

  18. 125I Radioimmunoassay of serum ursodeoxycholyl conjugates

    International Nuclear Information System (INIS)

    Hill, A.; Ross, P.E.; Bouchier, I.A.D.

    1983-01-01

    A radioimmunoassay for serum ursodeoxycholic conjugates using an iodine-125 ligand has been developed. The bile acid was present in normal fasting serum (0.19 +- SD 0.19 μmol/l, n=24) and 2-hour post-prandial serum (0.8 +- SD 0.8 μmol/l, n=16). Gallstone patients undergoing oral ursodeoxycholic acid therapy had significantly higher post-prandial serum levels (21.5 +- SD 14.0 μmol/l, n=15) by radioimmunoassay. Gas liquid chromatography analysis indicated that in normal serum ursodeoxycholic acid was totally conjugated, whereas sera from gallstone patients contained a proportion as the free bile acid (10.2 +- SD 8.1 μmol/l, n=15). Following an oral dose of ursodeoxycholic acid, both unconjugated and conjugated forms of the bile acid appeared in the serum of healthy individuals. (Auth.)

  19. Novel β-cyclodextrin–eosin conjugates

    Directory of Open Access Journals (Sweden)

    Gábor Benkovics

    2017-03-01

    Full Text Available Eosin B (EoB and eosin Y (EoY, two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin–EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin–EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  20. Novel β-cyclodextrin-eosin conjugates.

    Science.gov (United States)

    Benkovics, Gábor; Afonso, Damien; Darcsi, András; Béni, Szabolcs; Conoci, Sabrina; Fenyvesi, Éva; Szente, Lajos; Malanga, Milo; Sortino, Salvatore

    2017-01-01

    Eosin B (EoB) and eosin Y (EoY), two xanthene dye derivatives with photosensitizing ability were prepared in high purity through an improved synthetic route. The dyes were grafted to a 6-monoamino-β-cyclodextrin scaffold under mild reaction conditions through a stable amide linkage using the coupling agent 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride. The molecular conjugates, well soluble in aqueous medium, were extensively characterized by 1D and 2D NMR spectroscopy and mass spectrometry. Preliminary spectroscopic investigations showed that the β-cyclodextrin-EoY conjugate retains both the fluorescence properties and the capability to photogenerate singlet oxygen of the unbound chromophore. In contrast, the corresponding β-cyclodextrin-EoB conjugate did not show either relevant emission or photosensitizing activity probably due to aggregation in aqueous medium, which precludes any response to light excitation.

  1. Deciphering conjugative plasmid permissiveness in wastewater microbiomes

    DEFF Research Database (Denmark)

    Jacquiod, Samuel Jehan Auguste; Brejnrod, Asker Daniel; Milani, Stefan Morberg

    2017-01-01

    Wastewater treatment plants (WWTPs) are designed to robustly treat polluted water. They are characterized by ceaseless flows of organic, chemical and microbial matter, followed by treatment steps before environmental release. WWTPs are hotspots of horizontal gene transfer between bacteria via...... still remains largely uncharted. Furthermore, current in vitro methods used to assess conjugation in complex microbiomes do not include in situ behaviours of recipient cells, resulting in partial understanding of transfers. We investigated the in vitro conjugation capacities of WWTP microbiomes from...... inlet sewage and outlet treated water using the broad-host range IncP-1 conjugative plasmid, pKJK5. A thorough molecular approach coupling metagenomes to 16S rRNA DNA/cDNA amplicon sequencing was established to characterize microbiomes using the ecological concept of functional response groups. A broad...

  2. Conjugate gradient algorithms using multiple recursions

    Energy Technology Data Exchange (ETDEWEB)

    Barth, T.; Manteuffel, T.

    1996-12-31

    Much is already known about when a conjugate gradient method can be implemented with short recursions for the direction vectors. The work done in 1984 by Faber and Manteuffel gave necessary and sufficient conditions on the iteration matrix A, in order for a conjugate gradient method to be implemented with a single recursion of a certain form. However, this form does not take into account all possible recursions. This became evident when Jagels and Reichel used an algorithm of Gragg for unitary matrices to demonstrate that the class of matrices for which a practical conjugate gradient algorithm exists can be extended to include unitary and shifted unitary matrices. The implementation uses short double recursions for the direction vectors. This motivates the study of multiple recursion algorithms.

  3. Conjugated Polymers as Actuators: Modes of Actuation

    DEFF Research Database (Denmark)

    Skaarup, Steen

    2004-01-01

    The physical and chemical properties of conjugated polymers often depend very strongly on the degree of doping with anions or cations. The movement of ions in and out of the polymer matrix as it is redox cycled is also accompanied by mechanical changes. Both the volume and the stiffness can exhibit...... significant differences between the oxidized and reduced states. These effects form the basis of the use of conjugated polymers as actuators (or “artificial muscles”) controllable by a small (1-10 V) voltage. Three basic modes of actuation (bending, linear extension and stiffness change) have been proposed...

  4. Conjugated polymers as actuators: modes of actuation

    DEFF Research Database (Denmark)

    Skaarup, Steen

    2007-01-01

    The physical and chemical properties of conjugated polymers often depend very strongly on the degree of doping with anions or cations. The movement of ions in and out of the polymer matrix as it is redox cycled is also accompanied by mechanical changes. Both the volume and the stiffness can exhibit...... significant differences between the oxidized and reduced states. These effects form the basis of the use of conjugated polymers as actuators (or “artificial muscles”) controllable by a small (1-10 V) voltage. Three basic modes of actuation (bending, linear extension and stiffness change) have been proposed...

  5. Functionalized conjugated polyelectrolytes design and biomedical applications

    CERN Document Server

    Wang, Shu

    2014-01-01

    Functionalized Conjugated Polyelectrolytes presents a comprehensive review of these polyelectrolytes and their biomedical applications. Basic aspects like molecular design and optoelectronic properties are covered in the first chapter. Emphasis is placed on the various applications including sensing (chemical and biological), disease diagnosis, cell imaging, drug/gene delivery and disease treatment. This book explores a multi-disciplinary topic of interest to researchers working in the fields of chemistry, materials, biology and medicine. It also offers an integrated perspective on both basic research and application issues. Functionalized conjugated polyelectrolyte materials, which have already drawn considerable interest, will become a major new direction for biomedicine development.

  6. cAMP and EPAC are key players in the regulation of the signal transduction pathway involved in the α-hemolysin autophagic response.

    Directory of Open Access Journals (Sweden)

    María Belén Mestre

    Full Text Available Staphylococcus aureus is a microorganism that causes serious diseases in the human being. This microorganism is able to escape the phagolysosomal pathway, increasing intracellular bacterial survival and killing the eukaryotic host cell to spread the infection. One of the key features of S. aureus infection is the production of a series of virulence factors, including secreted enzymes and toxins. We have shown that the pore-forming toxin α-hemolysin (Hla is the S. aureus-secreted factor responsible for the activation of the autophagic pathway and that this response occurs through a PI3K/Beclin1-independent form. In the present report we demonstrate that cAMP has a key role in the regulation of this autophagic response. Our results indicate that cAMP is able to inhibit the autophagy induced by Hla and that PKA, the classical cAMP effector, does not participate in this regulation. We present evidence that EPAC and Rap2b, through calpain activation, are the proteins involved in the regulation of Hla-induced autophagy. Similar results were obtained in cells infected with different S. aureus strains. Interestingly, in this report we show, for the first time to our knowledge, that both EPAC and Rap2b are recruited to the S. aureus-containing phagosome. We believe that our findings have important implications in understanding innate immune processes involved in intracellular pathogen invasion of the host cell.

  7. Identification of novel autophagic Radix Polygalae fraction by cell membrane chromatography and UHPLC-(Q)TOF-MS for degradation of neurodegenerative disease proteins.

    Science.gov (United States)

    Wu, An-Guo; Wong, Vincent Kam-Wai; Zeng, Wu; Liu, Liang; Law, Betty Yuen-Kwan

    2015-11-24

    With its traditional use in relieving insomnia and anxiety, our previous study has identified onjisaponin B from Radix Polygalae (RP), as a novel autophagic enhancer with potential neuroprotective effects. In current study, we have further identified a novel active fraction from RP, contains 17 major triterpenoid saponins including the onjisaponin B, by the combinational use of cell membrane chromatography (CMC) and ultra-performance liquid chromatography coupled to (quadrupole) time-of-flight mass spectrometry {UHPLC-(Q)TOF-MS}. By exhibiting more potent autophagic effect in cells, the active fraction enhances the clearance of mutant huntingtin, and reduces protein level and aggregation of α-synuclein in a higher extent when compared with onjisaponin B. Here, we have reported for the first time the new application of cell-based CMC and UHPLC-(Q)TOF-MS analysis in identifying new autophagy inducers with neuroprotective effects from Chinese medicinal herb. This result has provided novel insights into the possible pharmacological actions of the active components present in the newly identified active fraction of RP, which may help to improve the efficacy of the traditional way of prescribing RP, and also provide new standard for the quality control of decoction of RP or its medicinal products in the future.

  8. HBV subgenotypes F1b and F4 replication induces an incomplete autophagic process in hepatocytes: Role of BCP and preCore mutations.

    Science.gov (United States)

    Elizalde, María Mercedes; Pérez, Paula Soledad; Sevic, Ina; Grasso, Daniel; Ropolo, Alejandro; Barbini, Luciana; Campos, Rodolfo Héctor; Vaccaro, María Inés; Flichman, Diego Martín

    2018-01-01

    Hepatitis B virus (HBV) genotypes and mutants have been associated with differences in clinical and virological characteristics. Autophagy is a cellular process that degrades long-lived proteins and damaged organelles. Viruses have evolved mechanisms to alter this process to survive in host cells. In this work, we studied the modulation of autophagy by the replication of HBV subgenotypes F1b and F4, and the naturally occurring mutants BCP and preCore. HBV subgenotypes F1b and F4 replication induced accumulation of autophagosomes in hepatoma cells. However, no autophagic protein degradation was observed, indicating a blockage of autophagic flux at later stages. This inhibition of autophagy flux might be due to an impairment of lysosomal acidification in hepatoma cells. Moreover, HBV-mediated autophagy modulation was independent of the viral subgenotypes and enhanced in viruses with BCP and preCore naturally occurring mutations. These results contribute to understand the mechanisms by which different HBV variants contribute to the pathogenesis of HBV infections. In addition, this study is the first to describe the role that two highly prevalent naturally occurring mutations exert on the modulation of HBV-induced autophagy.

  9. Effect of natural uranium on the UMR-106 osteoblastic cell line: impairment of the autophagic process as an underlying mechanism of uranium toxicity.

    Science.gov (United States)

    Pierrefite-Carle, Valérie; Santucci-Darmanin, Sabine; Breuil, Véronique; Gritsaenko, Tatiana; Vidaud, Claude; Creff, Gaelle; Solari, Pier Lorenzo; Pagnotta, Sophie; Al-Sahlanee, Rasha; Auwer, Christophe Den; Carle, Georges F

    2017-04-01

    Natural uranium (U), which is present in our environment, exerts a chemical toxicity, particularly in bone where it accumulates. Generally, U is found at oxidation state +VI in its oxocationic form [Formula: see text] in aqueous media. Although U(VI) has been reported to induce cell death in osteoblasts, the cells in charge of bone formation, the molecular mechanism for U(VI) effects in these cells remains poorly understood. The objective of our study was to explore U(VI) effect at doses ranging from 5 to 600 µM, on mineralization and autophagy induction in the UMR-106 model osteoblastic cell line and to determine U(VI) speciation after cellular uptake. Our results indicate that U(VI) affects mineralization function, even at subtoxic concentrations (metal exposure. We observed that U(VI) was able to rapidly activate autophagy but an inhibition of the autophagic flux was observed after 24 h. Thus, our results indicate that U(VI) perturbs osteoblastic functions by reducing mineralization capacity. Our study identifies for the first time U(VI) in the form of meta-autunite in mammalian cells. In addition, U(VI)-mediated inhibition of the autophagic flux may be one of the underlying mechanisms leading to the decreased mineralization and the toxicity observed in osteoblasts.

  10. ER Stress and Autophagic Perturbations Lead to Elevated Extracellular α-Synuclein in GBA-N370S Parkinson's iPSC-Derived Dopamine Neurons

    Directory of Open Access Journals (Sweden)

    Hugo J.R. Fernandes

    2016-03-01

    Full Text Available Heterozygous mutations in the glucocerebrosidase gene (GBA represent the strongest common genetic risk factor for Parkinson's disease (PD, the second most common neurodegenerative disorder. However, the molecular mechanisms underlying this association are still poorly understood. Here, we have analyzed ten independent induced pluripotent stem cell (iPSC lines from three controls and three unrelated PD patients heterozygous for the GBA-N370S mutation, and identified relevant disease mechanisms. After differentiation into dopaminergic neurons, we observed misprocessing of mutant glucocerebrosidase protein in the ER, associated with activation of ER stress and abnormal cellular lipid profiles. Furthermore, we observed autophagic perturbations and an enlargement of the lysosomal compartment specifically in dopamine neurons. Finally, we found increased extracellular α-synuclein in patient-derived neuronal culture medium, which was not associated with exosomes. Overall, ER stress, autophagic/lysosomal perturbations, and elevated extracellular α-synuclein likely represent critical early cellular phenotypes of PD, which might offer multiple therapeutic targets.

  11. Lithium chloride contributes to blood-spinal cord barrier integrity and functional recovery from spinal cord injury by stimulating autophagic flux.

    Science.gov (United States)

    Tong, Minji; He, Zili; Lin, Xiaoxiao; Zhou, Yulong; Wang, Qingqing; Zheng, Zengming; Chen, Jian; Xu, Huazi; Tian, Naifeng

    2018-01-22

    Blood-spinal cord barrier (BSCB) disruption following spinal cord injury (SCI) significantly compromises functional neuronal recovery. Autophagy is a potential therapeutic target when seeking to protect the BSCB. We explored the effects of lithium chloride (LiCl) on BSCB permeability and autophagy-induced SCI both in a rat model of SCI and in endothelial cells subjected to oxygen-glucose deprivation. We evaluated BSCB status using the Evans Blue dye extravasation test and measurement of tight junction (TJ) protein levels; we also assessed functional locomotor recovery. We detected autophagy-associated proteins in vivo and in vitro using both Western blotting and immunofluorescence staining. We found that, in a rat model of SCI, LiCl attenuated the elevation in BSCB permeability, improved locomotor recovery, and inhibited the degradation of TJ proteins including occludin and claudin-5. LiCl significantly induced the extent of autophagic flux after SCI by increasing LC3-II and ATG-5 levels, and abolishing p62 accumulation. In addition, a combination of LiCl and the autophagy inhibitor chloroquine not only partially eliminated the BSCB-protective effect of LiCl, but also exacerbated TJ protein degradation both in vivo and in vitro. Together, these findings suggest that LiCl treatment alleviates BSCB disruption and promotes locomotor recovery after SCI, partly by stimulating autophagic flux. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Autophagic cell death induced by reactive oxygen species is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells.

    Science.gov (United States)

    Yuan, Guang-Jin; Deng, Jun-Jian; Cao, De-Dong; Shi, Lei; Chen, Xin; Lei, Jin-Ju; Xu, Xi-Ming

    2017-08-14

    To investigate whether autophagic cell death is involved in hyperthermic sensitization to ionizing radiation in human hepatocellular carcinoma cells, and to explore the underlying mechanism. Human hepatocellular carcinoma cells were treated with hyperthermia and ionizing radiation. MTT and clonogenic assays were performed to determine cell survival. Cell autophagy was detected using acridine orange staining and flow cytometric analysis, and the expression of autophagy-associated proteins, LC3 and p62, was determined by Western blot analysis. Intracellular reactive oxygen species (ROS) were quantified using the fluorescent probe DCFH-DA. Treatment with hyperthermia and ionizing radiation significantly decreased cell viability and surviving fraction as compared with hyperthermia or ionizing radiation alone. Cell autophagy was significantly increased after ionizing radiation combined with hyperthermia treatment, as evidenced by increased formation of acidic vesicular organelles, increased expression of LC3II and decreased expression of p62. Intracellular ROS were also increased after combined treatment with hyperthermia and ionizing radiation. Pretreatment with N-acetylcysteine, an ROS scavenger, markedly inhibited the cytotoxicity and cell autophagy induced by hyperthermia and ionizing radiation. Autophagic cell death is involved in hyperthermic sensitization of cancer cells to ionizing radiation, and its induction may be due to the increased intracellular ROS.

  13. Carbon and nitrogen depletion-induced nucleophagy and selective autophagic sequestration of a whole nucleus in multinucleate cells of the filamentous fungus Aspergillus oryzae.

    Science.gov (United States)

    Kikuma, Takashi; Mitani, Takahiro; Kohara, Takahiro; Maruyama, Jun-Ichi; Kitamoto, Katsuhiko

    2017-05-12

    Autophagy is a conserved cellular degradation process in eukaryotes, in which cytoplasmic components and organelles are digested in vacuoles/lysosomes. Recently, autophagic degradation of nuclear materials, termed "nucleophagy", has been reported. In the multinucleate filamentous fungus Aspergillus oryzae, a whole nucleus is degraded by nucleophagy after prolonged culture. While developing an H2B-EGFP processing assay for the evaluation of nucleophagy in A. oryzae, we found that nucleophagy is efficiently induced by carbon or nitrogen depletion. Microscopic observations in a carbon depletion condition clearly demonstrated that autophagosomes selectively sequester a particular nucleus, despite the presence of multiple nuclei in the same cell. Furthermore, AoNsp1, the A. oryzae homolog of the yeast nucleoporin Nsp1p, mainly localized at the nuclear periphery, but its localization was restricted to the opposite side of the autophagosome being formed around a nucleus. In contrast, the perinuclear ER visualized with the calnexin AoClxA was not morphologically affected by nucleophagy. The findings of nucleophagy-inducing conditions enabled us to characterize the morphological process of autophagic degradation of a whole nucleus in multinucleate cells.

  14. The reverse-mode NCX1 activity inhibitor KB-R7943 promotes prostate cancer cell death by activating the JNK pathway and blocking autophagic flux.

    Science.gov (United States)

    Long, Zhou; Chen, BaiJun; Liu, Qian; Zhao, Jiang; Yang, ZhenXing; Dong, XingYou; Xia, LiuBin; Huang, ShengQuan; Hu, XiaoYan; Song, Bo; Li, LongKun

    2016-07-05

    We explored the effects of KB-R7943, an inhibitor of reverse-mode NCX1 activity, in prostate cancer (PCa). NCX1 was overexpressed in PCa tissues and cell lines, and higher NCX1 levels were associated higher PCa grades. At concentrations greater than 10 μM, KB-R7943 dose-dependently decreased PC3 and LNCaP cell viability. KB-R7943 also increased cell cycle G1/S phase arrest and induced apoptosis in PC3 cells. KB-R7943 increased autophagosome accumulation in PCa cells as indicated by increases in LC3-II levels and eGFP-LC3 puncta. Combined treatment with chloroquine (CQ) and KB-R7943 decreased P62 and increased LC3-II protein levels in PC3 cells, indicating that KB-R7943 blocked autophagic flux. KB-R7943 induced autophagosome accumulation mainly by downregulating the PI3K/AKT/m-TOR pathway and upregulating the JNK pathway. In xenograft experiments, KB-R7943 inhibited tumor growth. Combined treatment with KB-R7943 and an autophagy inhibitor inhibited growth and increased apoptosis. These results indicate that KB-R7943 promotes cell death in PCa by activating the JNK signaling pathway and blocking autophagic flux.

  15. The Ketone Body, β-Hydroxybutyrate Stimulates the Autophagic Flux and Prevents Neuronal Death Induced by Glucose Deprivation in Cortical Cultured Neurons.

    Science.gov (United States)

    Camberos-Luna, Lucy; Gerónimo-Olvera, Cristian; Montiel, Teresa; Rincon-Heredia, Ruth; Massieu, Lourdes

    2016-03-01

    Glucose is the major energy substrate in brain, however, during ketogenesis induced by starvation or prolonged hypoglycemia, the ketone bodies (KB), acetoacetate and β-hydroxybutyrate (BHB) can substitute for glucose. KB improve neuronal survival in diverse injury models, but the mechanisms by which KB prevent neuronal damage are still not well understood. In the present study we have investigated whether protection by the D isomer of BHB (D-BHB) against neuronal death induced by glucose deprivation (GD), is related to autophagy. Autophagy is a lysosomal-dependent degradation process activated during nutritional stress, which leads to the digestion of damaged proteins and organelles providing energy for cell survival. Results show that autophagy is activated in cortical cultured neurons during GD, as indicated by the increase in the levels of the lipidated form of the microtubule associated protein light chain 3 (LC3-II), and the number of autophagic vesicles. At early phases of glucose reintroduction (GR), the levels of p62 declined suggesting that the degradation of the autophagolysosomal content takes place at this time. In cultures exposed to GD and GR in the presence of D-BHB, the levels of LC3-II and p62 rapidly declined and remained low during GR, suggesting that the KB stimulates the autophagic flux preventing autophagosome accumulation and improving neuronal survival.

  16. Receptor-targeted aptamer-siRNA conjugate-directed transcriptional regulation of HIV-1

    Science.gov (United States)

    Zhou, Jiehua; Lazar, Daniel; Li, Haitang; Xia, Xin; Satheesan, Sangeetha; Charlins, Paige; O'Mealy, Denis; Akkina, Ramesh; Saayman, Sheena; Weinberg, Marc S.; Rossi, John J.; Morris, Kevin V.

    2018-01-01

    Gene-based therapies represent a promising therapeutic paradigm for the treatment of HIV-1, as they have the potential to maintain sustained viral inhibition with reduced treatment interventions. Such an option may represent a long-term treatment alternative to highly active antiretroviral therapy. Methods: We previously described a therapeutic approach, referred to as transcriptional gene silencing (TGS), whereby small noncoding RNAs directly inhibit the transcriptional activity of HIV-1 by targeting sites within the viral promoter, specifically the 5' long terminal repeat (LTR). TGS differs from traditional RNA interference (RNAi) in that it is characterized by concomitant silent-state epigenetic marks on histones and DNA. To deliver TGS-inducing RNAs, we developed functional RNA conjugates based on the previously reported dual function of the gp120 (A-1) aptamer conjugated to 27-mer Dicer-substrate anti-HIV-1 siRNA (dsiRNA), LTR-362. Results: We demonstrate here that high levels of processed guide RNAs localize to the nucleus in infected T lymphoblastoid CEM cell line and primary human CD4+ T-cells. Treatment of the aptamer-siRNA conjugates induced TGS with an ~10-fold suppression of viral p24 levels as measured at day 12 post infection. To explore the silencing efficacy of aptamer-siRNA conjugates in vivo, HIV-1-infected humanized NOD/SCID/IL2 rγnull mice (hu-NSG) were treated with the aptamer-siRNA conjugates. Systemic delivery of the A-1-stick-LTR-362 27-mer siRNA conjugates suppressed HIV-1 infection and protected CD4+ T cell levels in viremia hu-NSG mice. Principle conclusions: Collectively these data suggest that the gp120 aptamer-dsiRNA conjugate design is suitable for systemic delivery of small RNAs that can be used to suppress HIV-1. PMID:29556342

  17. Study of conjugation and radiolabeling of monoclonal antibody rituximab for use in radionuclide therapy

    International Nuclear Information System (INIS)

    Massicano, Adriana Vidal Fernandes

    2011-01-01

    Lymphomas are tumors originated from the transformation of a lymphocyte in the lymphatic system. The most common lymphoma is the Non-Hodgkin Lymphoma (NHL). Advances in immunology and molecular biology have been improving NHL's detection and treatment strategies development, such as Radioimmunotherapy (RIT). Rituximab is an anti-CD20 monoclonal antibody used as immunotherapeutic to treat refractory or relapsed NHL. The goal of the present work was to conjugate this antibody to DOTA-NHS-ester bifunctional chelator and to radiolabel it with 177 Lu radioisotope in order to develop a radio immunotherapeutic agent for NHL's treatment. Different rituximab to DOTA molar ratios (1:5, 1:10, 1:20, 1:50, 1:250, 1:500 and 1:1000) were evaluated in order to determine the best condition for obtaining the highest radiochemical purity of radio immunotherapeutic. The stability of the unlabeled immuno conjugated was evaluated by high performance liquid chromatography (HPLC) for up to 240 days in different storage conditions. The stability of the labeled preparations was evaluated either after storing at 2-8 degree C or incubation in human serum at 37 degree C. The binding to serum proteins was also determined. In vivo studies were performed in healthy Swiss mice, in order to characterize the biological properties of labeled conjugate. Finally, preliminary studies of radio immuno conjugated competitive binding to CD20 positive Raji cells were carried out in order to analyze if the process of conjugation and radiolabeling compromises the immunoreactivity of the antibody. The conjugation applying lower antibody to chelator molar ratios (1:5, 1:10 and 1:20) showed high stability when stored for up to 240 days in different conditions. The HPLC analysis showed that the monoclonal antibody conjugated in molar ratio 1:50 was labeled with higher radiochemical purity (> 95%) when purified in PD-10 column. This conjugate showed reasonable stability at 2-8 degree C. The analysis of the

  18. Data on atherosclerosis specific antibody conjugation to nanoemulsions

    Directory of Open Access Journals (Sweden)

    Geoffrey Prévot

    2017-12-01

    Full Text Available This article present data related to the publication entitled “Iron oxide core oil-in-water nanoemulsion as tracer for atherosclerosis MPI and MRI imaging” (Prévot et al., 2017 [1]. Herein we describe the engineering in the baculovirus-insect cell system and purification processes of the human scFv-Fc TEG4-2C antibody, specific of platelets within the atheroma plaque. For molecular targeting purpose, atheroma specific antibody was conjugated to nanoemulsions (NEs using a heterobifunctional linker (DSPE-PEG-maleimide. Atheroma labelling was assayed by immunochemistry on arterial sections from rabbits.

  19. A finite element conjugate gradient FFT method for scattering

    Science.gov (United States)

    Collins, Jeffery D.; Ross, Dan; Jin, J.-M.; Chatterjee, A.; Volakis, John L.

    1991-01-01

    Validated results are presented for the new 3D body of revolution finite element boundary integral code. A Fourier series expansion of the vector electric and mangnetic fields is employed to reduce the dimensionality of the system, and the exact boundary condition is employed to terminate the finite element mesh. The mesh termination boundary is chosen such that is leads to convolutional boundary operatores of low O(n) memory demand. Improvements of this code are discussed along with the proposed formulation for a full 3D implementation of the finite element boundary integral method in conjunction with a conjugate gradiant fast Fourier transformation (CGFFT) solution.

  20. Nanostructured Conjugated Polymers for Energy-Related Applications beyond Solar Cells.

    Science.gov (United States)

    Xie, Jian; Zhao, Cui-E; Lin, Zong-Qiong; Gu, Pei-Yang; Zhang, Qichun

    2016-05-20

    To meet the ever-increasing requirements for the next generation of sustainable and versatile energy-related devices, conjugated polymers, which have potential advantages over small molecules and inorganic materials, are among the most promising types of green candidates. The properties of conjugated polymers can be tuned through modification of the structure and incorporation of different functional moieties. In addition, superior performances can be achieved as a result of the advantages of nanostructures, such as their large surface areas and the shortened pathways for charge transfer. Therefore, nanostructured conjugated polymers with different properties can be obtained to be applied in different energy-related organic devices. This review focuses on the application and performance of the recently reported nanostructured conjugated polymers for high-performance devices, including rechargeable lithium batteries, microbial fuel cells (MFCs), thermoelectric generators, and photocatalytic systems. The design strategies, reaction mechanisms, advantages, and limitations of nanostructured conjugated polymers are further discussed in each section. Finally, possible routes to improve the performances of the current systems are also included in the conclusion. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Comparison of linoleic and conjugated linoleic acids in enzymatic acidolysis of tristearin

    DEFF Research Database (Denmark)

    Yang, Tiankui; Xu, Xuebing; Li, L.T.

    2001-01-01

    tristearin (SSS) and linoleic (L) or conjugated linoleic (cL) acids (1:6, mol/mol). The other was between tristearin and the mixture of linoleic and conjugated linoleic acids (1:3:3, mol/mol/mol). Acyl incorporation and migration together with triacylglycerol composition of the products were monitored...... with gas chromatography, pancreatic lipase hydrolysis, and high performance liquid chromatography. Both acyl incorporation and migration of linoleic acid were faster than those of conjugated linoleic acid. At 5 h reaction, there were 13.0% LLL, 46.5% LSL, 27.7% LSS, and 5.6% SSS in the product for a system...... between tristearin and linoleic acid; whereas there were 2.4% cLcLcL, 10.4% cLScL, 50.9% cLSS, and 36.2% SSS in the product for a system between tristearin and conjugated linoleic acid. The results suggest that linoleic acid was more reactive than conjugated linoleic acid in the enzymatic acidolysis...

  2. Self-Assembly and Crystallization of Conjugated Block Copolymers

    Science.gov (United States)

    Davidson, Emily Catherine

    melting regimes are identified. A structural model of the conjugated block melting process is proposed, consisting of (I) excluded-chain relaxation followed by (II) chain inter-digitation during melt-recrystallization, and finally (III) complete melting independent of the initial crystallization conditions. These detailed studies of the impact of processing conditions suggest that crystallization processes coupled to temperature-dependent diffusion and nucleation are critical for determining the final crystalline state in confinement. They also suggest that, surprisingly, improvement in conjugated polymer crystallinity may correspond to a more compact structure along the chain dimension. Throughout this dissertation, we consider how key parameters governing structure formation impact self-assembly and crystallization. In particular, we consider the driving forces for crystallization versus microphase separation, the impact of conformational asymmetry, the drive for extended chain crystallites, and finally the role of detailed crystallization processes. The findings presented here demonstrate the biases introduced by conjugated polymers for the self-assembly and crystallization of such systems, and suggest design rules for the targeted creation of block copolymers containing high-performing conjugated polymers. (Abstract shortened by ProQuest.).

  3. Solving implicit multi-mesh flow and conjugate heat transfer problems with RELAP-7

    International Nuclear Information System (INIS)

    Zou, L.; Peterson, J.; Zhao, H.; Zhang, H.; Andrs, D.; Martineau, R.

    2013-01-01

    The fully implicit simulation capability of RELAP-7 to solve multi-mesh flow and conjugate heat transfer problems for reactor system safety analysis is presented. Compared to general single-mesh simulations, the reactor system safety analysis-type of code has unique challenges due to its highly simplified, interconnected, one-dimensional, and zero-dimensional flow network describing multiple physics with significantly different time and length scales. To use the Jacobian-free Newton Krylov-type of solver, preconditioning is generally required for the Krylov method. The uniqueness of the reactor safety analysis-type of code in treating the interconnected flow network and conjugate heat transfer also introduces challenges in providing preconditioning matrix. Typical flow and conjugate heat transfer problems involved in reactor safety analysis using RELAP-7, as well as the special treatment on the preconditioning matrix are presented in detail. (authors)

  4. Poly(ethylene glycol-Prodrug Conjugates: Concept, Design, and Applications

    Directory of Open Access Journals (Sweden)

    Shashwat S. Banerjee

    2012-01-01

    Full Text Available Poly(ethylene glycol (PEG is the most widely used polymer in delivering anticancer drugs clinically. PEGylation (i.e., the covalent attachment of PEG of peptides proteins, drugs, and bioactives is known to enhance the aqueous solubility of hydrophobic drugs, prolong circulation time, minimize nonspecific uptake, and achieve specific tumor targetability through the enhanced permeability and retention effect. Numerous PEG-based therapeutics have been developed, and several have received market approval. A vast amount of clinical experience has been gained which has helped to design PEG prodrug conjugates with improved therapeutic efficacy and reduced systemic toxicity. However, more efforts in designing PEG-based prodrug conjugates are anticipated. In light of this, the current paper highlights the synthetic advances in PEG prodrug conjugation methodologies with varied bioactive components of clinical relevance. In addition, this paper discusses FDA-approved PEGylated delivery systems, their intended clinical applications, and formulations under clinical trials.

  5. Comparison of eosin and fluorescein conjugates for the photoinitiation of cell-compatible polymer coatings.

    Directory of Open Access Journals (Sweden)

    Jacob L Lilly

    Full Text Available Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more sensitive initiation of gelation. However at higher functionalization densities, the thickness of fluorescein polymer films begins to rival that of eosin. Commercial fluorescein-conjugated antibodies are also capable of generating conformal, protective coatings on mammalian cells with similar viability and encapsulation efficiency as eosin systems.

  6. Comparison of eosin and fluorescein conjugates for the photoinitiation of cell-compatible polymer coatings.

    Science.gov (United States)

    Lilly, Jacob L; Gottipati, Anuhya; Cahall, Calvin F; Agoub, Mohamed; Berron, Brad J

    2018-01-01

    Targeted photopolymerization is the basis for multiple diagnostic and cell encapsulation technologies. While eosin is used in conjunction with tertiary amines as a water-soluble photoinitiation system, eosin is not widely sold as a conjugate with antibodies and other targeting biomolecules. Here we evaluate the utility of fluorescein-labeled bioconjugates to photopolymerize targeted coatings on live cells. We show that although fluorescein conjugates absorb approximately 50% less light energy than eosin in matched photopolymerization experiments using a 530 nm LED lamp, appreciable polymer thicknesses can still be formed in cell compatible environments with fluorescein photosensitization. At low photoinitiator density, eosin allows more sensitive initiation of gelation. However at higher functionalization densities, the thickness of fluorescein polymer films begins to rival that of eosin. Commercial fluorescein-conjugated antibodies are also capable of generating conformal, protective coatings on mammalian cells with similar viability and encapsulation efficiency as eosin systems.

  7. Plasmid transfer by conjugation in Xylella fastidiosa.

    Science.gov (United States)

    Recombination and horizontal gene transfer have been implicated in the adaption of Xylella fastidiosa (Xf) to infect a wide variety of different plant species. There is evidence that certain strains of Xf carry native plasmids equipped with transfer and mobilization genes, suggesting conjugation as ...

  8. Theory of periodic conjugate heat transfer

    CERN Document Server

    Zudin, Yuri B

    2016-01-01

    This book presents the theory of periodic conjugate heat transfer in detail. It offers a simplified description of the interaction between a solid body and a fluid as a boundary value problem of the heat conduction equation for the solid body.

  9. Stochastic differential equations used to model conjugation

    DEFF Research Database (Denmark)

    Philipsen, Kirsten Riber; Christiansen, Lasse Engbo

    Stochastic differential equations (SDEs) are used to model horizontal transfer of antibiotic resis- tance by conjugation. The model describes the concentration of donor, recipient, transconjugants and substrate. The strength of the SDE model over the traditional ODE models is that the noise can...

  10. Immunogenicity of novel sulfadimethoxide conjugates | Chen ...

    African Journals Online (AJOL)

    Immunogenicity of novel sulfadimethoxide conjugates. L Chen, J Su, X Zhang, L Li, X He. Abstract. Sulfadimethoxine (SDM) is an antibiotic commonly added to animal feeds. Anti-SDM antibodies are useful for the detection of residual SDM in foods, feeds and biological fluids by ELISA. In this study, we show that SDM is ...

  11. Women experiencing the intergenerationality of conjugal violence

    Directory of Open Access Journals (Sweden)

    Gilvânia Patrícia do Nascimento Paixão

    2015-10-01

    Full Text Available Objective: to analyze the family relationship, in childhood and adolescence, of women who experience conjugal violence.Method: qualitative study. Interviews were held with 19 women, who were experiencing conjugal violence, and who were resident in a community in Salvador, Bahia, Brazil. The project was approved by the Research Ethics Committee (N. 42/2011.Results: the data was organized using the Discourse of the Collective Subject, identifying the summary central ideas: they witnessed violence between their parents; they suffered repercussions from the violence between their parents: they were angry about the mother's submission to her partner; and they reproduced the conjugal violence. The discourse showed that the women witnessed, in childhood and adolescence, violence between their parents, and were injured both physically and psychologically. As a result of the mother's submission, feelings of anger arose in the children. However, in the adult phase of their own lives, they noticed that their conjugal life resembled that of their parents, reproducing the violence.Conclusion: investment is necessary in strategies designed to break inter-generational violence, and the health professionals are important in this process, as it is a phenomenon with repercussions in health. Because they work in the Family Health Strategy, which focuses on the prevention of harm and illness, health promotion and interdepartmentality, the nurses are essential in the process of preventing and confronting this phenomenon.

  12. Integrated circuits based on conjugated polymer monolayer.

    Science.gov (United States)

    Li, Mengmeng; Mangalore, Deepthi Kamath; Zhao, Jingbo; Carpenter, Joshua H; Yan, Hongping; Ade, Harald; Yan, He; Müllen, Klaus; Blom, Paul W M; Pisula, Wojciech; de Leeuw, Dago M; Asadi, Kamal

    2018-01-31

    It is still a great challenge to fabricate conjugated polymer monolayer field-effect transistors (PoM-FETs) due to intricate crystallization and film formation of conjugated polymers. Here we demonstrate PoM-FETs based on a single monolayer of a conjugated polymer. The resulting PoM-FETs are highly reproducible and exhibit charge carrier mobilities reaching 3 cm 2  V -1  s -1 . The high performance is attributed to the strong interactions of the polymer chains present already in solution leading to pronounced edge-on packing and well-defined microstructure in the monolayer. The high reproducibility enables the integration of discrete unipolar PoM-FETs into inverters and ring oscillators. Real logic functionality has been demonstrated by constructing a 15-bit code generator in which hundreds of self-assembled PoM-FETs are addressed simultaneously. Our results provide the state-of-the-art example of integrated circuits based on a conjugated polymer monolayer, opening prospective pathways for bottom-up organic electronics.

  13. Conjugate problems in convective heat transfer

    CERN Document Server

    Dorfman, Abram S

    2009-01-01

    The conjugate heat transfer (CHT) problem takes into account the thermal interaction between a body and fluid flowing over or through it, a key consideration in both mechanical and aerospace engineering. Presenting more than 100 solutions of non-isothermal and CHT problems, this title considers the approximate solutions of CHT problems.

  14. Compositions for directed alignment of conjugated polymers

    Science.gov (United States)

    Kim, Jinsang; Kim, Bong-Gi; Jeong, Eun Jeong

    2016-04-19

    Conjugated polymers (CPs) achieve directed alignment along an applied flow field and a dichroic ratio of as high as 16.67 in emission from well-aligned thin films and fully realized anisotropic optoelectronic properties of CPs in field-effect transistor (FET).

  15. Conjugated Polymer Actuators: Prospects and Limitations

    DEFF Research Database (Denmark)

    Skaarup, Steen

    2007-01-01

    Actuators constructed with a conjugated polymer as the active part have been predicted to have a number of highly desirable properties: Large mechanical strength, high power density, i.e. high actuation speeds possible, sufficient maximum strain values, high reversibility and safe, low voltages (1...

  16. Some aspects of geomagnetically conjugate phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Rycroft, M.J.

    1987-12-01

    Both charged particles and waves convey information about the thermosphere, ionosphere and magnetosphere from the Northern to the Southern Hemisphere and vice versa, along geomagnetic flux tubes.The interhemispheric travel time of electrons or ions, being dependent upon L-value , pitch angle and energy (which may lie between less than or equal to 1 eV and greater than or equal to 1 MeV) may be many hours, ranging down to less than or equal to 1 s. However, the one-hop propagation time for magnetohydrodynamic or whistler mode waves generally lies between 10/sup 2/s and 1 s. Such times, therefore, give the time scales of transient phenomena that are geomagnetically conjugate and of changes in steady-state plasma processes occurring in geomagnetically conjugate regions. Contrasting examples are presented of conjugate physical phenomena, obtained using satellite, rocket, aircraft and ground-based observations; the latter capitalise upon the rather rare disposition of land - rather than ocean - at each end of a geophysically interesting flux tube. Particular attention is paid to the interactions between whistler mode waves and energetic electrons. Geomagnetic, radio, optical and plasma observations, taken together with model computations, provide a wealth of knowledge on conjugate phenomena and their dependence on conditions in the solar wind, substorms, L-value, etc... Finally, some suggestions are made for future lines of research.

  17. Cross-Conjugated n-Dopable Aromatic Polyketone

    NARCIS (Netherlands)

    Voortman, Thomas P.; Bartesaghi, Davide; Koster, L. Jan Anton; Chiechi, Ryan C.

    2015-01-01

    This paper describes the synthesis and characterization of a high molecular weight cross-conjugated polyketone synthesized via scalable Friedel Crafts chemistry. Cross-conjugated polyketones are precursors to conjugated polyions; they become orders of magnitude more conductive after a two-electron

  18. Bis-polymer lipid-peptide conjugates and nanoparticles thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Ting; Dong, He; Shu, Jessica; Dube, Nikhil

    2018-04-24

    The present invention provides bis-polymer lipid-peptide conjugates containing a hydrophobic block and headgroup containing a helical peptide and two polymer blocks. The conjugates can self-assemble to form helix bundle subunits, which in turn assemble to provide micellar nanocarriers for drug cargos and other agents. Particles containing the conjugates and methods for forming the particles are also disclosed.

  19. Comparison of preconditioned generalized conjugate gradient methods to two-dimensional neutron and photon transport equation

    International Nuclear Information System (INIS)

    Chen, G.S.; Yang, D.Y.

    1998-01-01

    We apply and compare the preconditioned generalized conjugate gradient methods to solve the linear system equation that arises in the two-dimensional neutron and photon transport equation in this paper. Several subroutines are developed on the basis of preconditioned generalized conjugate gradient methods for time-independent, two-dimensional neutron and photon transport equation in the transport theory. These generalized conjugate gradient methods are used: TFQMR (transpose free quasi-minimal residual algorithm) CGS (conjugate gradient square algorithm), Bi-CGSTAB (bi-conjugate gradient stabilized algorithm) and QMRCGSTAB (quasi-minimal residual variant of bi-conjugate gradient stabilized algorithm). These subroutines are connected to computer program DORT. Several problems are tested on a personal computer with Intel Pentium CPU. The reasons to choose the generalized conjugate gradient methods are that the methods have better residual (equivalent to error) control procedures in the computation and have better convergent rate. The pointwise incomplete LU factorization ILU, modified pointwise incomplete LU factorization MILU, block incomplete factorization BILU and modified blockwise incomplete LU factorization MBILU are the preconditioning techniques used in the several testing problems. In Bi-CGSTAB, CGS, TFQMR and QMRCGSTAB method, we find that either CGS or Bi-CGSTAB method combined with preconditioner MBILU is the most efficient algorithm in these methods in the several testing problems. The numerical solution of flux by preconditioned CGS and Bi-CGSTAB methods has the same result as those from Cray computer, obtained by either the point successive relaxation method or the line successive relaxation method combined with Gaussian elimination

  20. Tumour eradication using synchronous thermal ablation and Hsp90 chemotherapy with protein engineered triblock biopolymer-geldanamycin conjugates.

    Science.gov (United States)

    Chen, Yizhe; Youn, Pilju; Pysher, Theodore J; Scaife, Courtney L; Furgeson, Darin Y

    2014-12-01

    Hepatocellular carcinoma (HCC) suffers high tumour recurrence rate after thermal ablation. Heat shock protein 90 (Hsp90) induced post-ablation is critical for tumour survival and progression. A combination therapy of thermal ablation and polymer conjugated Hsp90 chemotherapy was designed and evaluated for complete tumour eradication of HCC. A thermo-responsive, elastin-like polypeptide (ELP)-based tri-block biopolymer was developed and conjugated with a potent Hsp90 inhibitor, geldanamycin (GA). The anti-cancer efficacy of conjugates was evaluated in HCC cell cultures with and without hyperthermia (43 °C). The conjugates were also administered twice weekly in a murine HCC model as a single treatment or in combination with single electrocautery as the ablation method. ELP-GA conjugates displayed enhanced cytotoxicity in vitro and effective heat shock inhibition under hyperthermia. The conjugates alone significantly slowed the tumour growth without systemic toxicity. Four doses of thermo-responsive ELP-GA conjugates with concomitant simple electrocautery accomplished significant Hsp90 inhibition and sustained tumour suppression. Hsp90 inhibition plays a key role in preventing the recurrence of HCC, and the combination of ablation with targeted therapy holds great potential to improve prognosis and survival of HCC patients.

  1. Elucidation of the Structure Formation of Polymer-Conjugated Proteins in Solution and Block Copolymer Templates

    Science.gov (United States)

    Ferebee, Rachel L.

    The broader technical objective of this work is to contribute to the development of enzyme-functionalized nanoporous membranes that can function as autonomous and target selective dynamic separators. The scientific objective of the research performed within this thesis is to elucidate the parameters that control the mixing of proteins in organic host materials and in block copolymers templates in particular. A "biomimetic" membrane system that uses enzymes to selectively neutralize targets and trigger a change in permeability of nanopores lined with a pH-responsive polymer has been fabricated and characterized. Mechanical and functional stability, as well as scalability, have been demonstrated for this system. Additional research has focused on the role of polymeric ligands on the solubility characteristics of the model protein, Bovine Serum Albumin (BSA). For this purpose BSA was conjugated with poly(ethylene glycol) (PEG) ligands of varied degree of polymerization and grafting density. Combined static and dynamic light scattering was used (in conjunction with MALDI-TOF) to determine the second virial coefficient in PBS solutions. At a given mass fraction PEG or average number of grafts, the solubility of BSA-PEG conjugates is found to increase with the degree of polymerization of conjugated PEG. This result informs the synthesis of protein-conjugate systems that are optimized for the fabrication of block copolymer blend materials with maximum protein loading. Blends of BSA-PEG conjugates and block copolymer (BCP) matrices were fabricated to evaluate the dispersion morphology and solubility limits in a model system. Electron microscopy was used to evaluate the changes in lamellar spacing with increased filling fraction of BSA-PEG conjugates.

  2. Generation of a CRISPR database for Yersinia pseudotuberculosis complex and role of CRISPR-based immunity in conjugation.

    Science.gov (United States)

    Koskela, Katja A; Mattinen, Laura; Kalin-Mänttäri, Laura; Vergnaud, Gilles; Gorgé, Olivier; Nikkari, Simo; Skurnik, Mikael

    2015-11-01

    The clustered regularly interspaced short palindromic repeat - CRISPR-associated genes (CRISPR-Cas) system is used by bacteria and archaea against invading conjugative plasmids or bacteriophages. Central to this immunity system are genomic CRISPR loci that contain fragments of invading DNA. These are maintained as spacers in the CRISPR loci between direct repeats and the spacer composition in any bacterium reflects its evolutionary history. We analysed the CRISPR locus sequences of 335 Yersinia pseudotuberculosis complex strains. Altogether 1902 different spacer sequences were identified and these were used to generate a database for the spacer sequences. Only ∼10% of the spacer sequences found matching sequences. In addition, surprisingly few spacers were shared by Yersinia pestis and Y. pseudotuberculosis strains. Interestingly, 32 different protospacers were present in the conjugative plasmid pYptb32953. The corresponding spacers were identified from 35 different Y. pseudotuberculosis strains indicating that these strains had encountered pYptb32953 earlier. In conjugation experiments, pYptb32953-specific spacers generally prevented conjugation with spacer-positive and spacer-free strains. However, some strains with one to four spacers were invaded by pYptb32953 and some spacer-free strains were fully resistant. Also some spacer-positive strains were intermediate resistant to conjugation. This suggests that one or more other defence systems are determining conjugation efficiency independent of the CRISPR-Cas system. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. Honokiol induces autophagic cell death in malignant glioma through reactive oxygen species-mediated regulation of the p53/PI3K/Akt/mTOR signaling pathway

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Chien-Ju [Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan (China); Comprehensive Cancer Center, Taipei Medical University, Taipei, Taiwan (China); Chen, Ta-Liang [Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan (China); Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan (China); Tseng, Yuan-Yun [Department of Neurosurgery, Shuang-Ho Hospital, Taipei Medical University, Taipei, Taiwan (China); Wu, Gong-Jhe [Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan (China); Hsieh, Ming-Hui [Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan (China); Department of Anesthesiology, Taipei Medical University Hospital, Taipei, Taiwan (China); Lin, Yung-Wei [Brain Disease Research Center, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan (China); Chen, Ruei-Ming, E-mail: rmchen@tmu.edu.tw [Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan (China); Anesthetics and Toxicology Research Center, Taipei Medical University Hospital, Taipei, Taiwan (China); Brain Disease Research Center, Taipei Medical University Wan-Fang Hospital, Taipei, Taiwan (China); Comprehensive Cancer Center, Taipei Medical University, Taipei, Taiwan (China)

    2016-08-01

    Honokiol, an active constituent extracted from the bark of Magnolia officinalis, possesses anticancer effects. Apoptosis is classified as type I programmed cell death, while autophagy is type II programmed cell death. We previously proved that honokiol induces cell cycle arrest and apoptosis of U87 MG glioma cells. Subsequently in this study, we evaluated the effect of honokiol on autophagy of glioma cells and examined the molecular mechanisms. Administration of honokiol to mice with an intracranial glioma increased expressions of cleaved caspase 3 and light chain 3 (LC3)-II. Exposure of U87 MG cells to honokiol also induced autophagy in concentration- and time-dependent manners. Results from the addition of 3-methyladenine, an autophagy inhibitor, and rapamycin, an autophagy inducer confirmed that honokiol-induced autophagy contributed to cell death. Honokiol decreased protein levels of PI3K, phosphorylated (p)-Akt, and p-mammalian target of rapamycin (mTOR) in vitro and in vivo. Pretreatment with a p53 inhibitor or transfection with p53 small interfering (si)RNA suppressed honokiol-induced autophagy by reversing downregulation of p-Akt and p-mTOR expressions. In addition, honokiol caused generation of reactive oxygen species (ROS), which was suppressed by the antioxidant, vitamin C. Vitamin C also inhibited honokiol-induced autophagic and apoptotic cell death. Concurrently, honokiol-induced alterations in levels of p-p53, p53, p-Akt, and p-mTOR were attenuated following vitamin C administration. Taken together, our data indicated that honokiol induced ROS-mediated autophagic cell death through regulating the p53/PI3K/Akt/mTOR signaling pathway. - Highlights: • Exposure of mice with intracranial gliomas to honokiol induces cell apoptosis and autophagy. • Honokiol triggers autophagy of human glioma cells via the PISK/AKT/mTOR signaling pathway. • P53 induces autophagy via regulating the AKT/mTOR pathway in honokiol-treated glioma cells. • ROS participates

  4. Nonlinear piezoelectricity in PZT ceramics for generating ultrasonic phase conjugate waves

    Science.gov (United States)

    Yamamoto; Kokubo; Sakai; Takagi

    2000-03-01

    We have succeeded in the generation of acoustic phase conjugate waves with nonlinear PZT piezoelectric ceramics and applied them to ultrasonic imaging systems. Our aim is to make a phase conjugator with 100% efficiency. For this purpose, it is important to clarify the mechanism of acoustic phase conjugation through nonlinear piezoelectricity. The process is explained by the parametric interaction via the third-order nonlinear piezoelectricity between the incident acoustic wave at angular frequency omega and the pump electric field at 2 omega. We solved the coupling equations including the third-ordered nonlinear piezoelectricity and theoretically derived the amplitude efficiency of the acoustic phase conjugation. We compared the efficiencies between the theoretical and experimental values for PZT ceramics with eight different compositions. Pb[(Zn1/3Nb2/3)(1 - x)Tix]O3 (X = 0.09, PZNT91/9) piezoelectric single crystals have been investigated for high-performance ultrasonic transducer application, because these have large piezoelectric constants, high electrical-mechanical coupling factors and high dielectric constants. We found that they have third-order nonlinear piezoelectric constants much larger than PZT and are hopeful that the material as a phase conjugator has over 100% efficiency.

  5. Cytotoxicity Effects of Different Surfactant Molecules Conjugated to Carbon Nanotubes on Human Astrocytoma Cells

    Science.gov (United States)

    Dong, Lifeng; Witkowski, Colette M.; Craig, Michael M.; Greenwade, Molly M.; Joseph, Katherine L.

    2009-12-01

    Phase contrast and epifluorescence microscopy were utilized to monitor morphological changes in human astrocytoma cells during a time-course exposure to single-walled carbon nanotube (SWCNT) conjugates with different surfactants and to investigate sub-cellular distribution of the nanotube conjugates, respectively. Experimental results demonstrate that cytotoxicity of the nanotube/surfactant conjugates is related to the toxicity of surfactant molecules attached on the nanotube surfaces. Both sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (SDBS) are toxic to cells. Exposure to CNT/SDS conjugates (0.5 mg/mL) for less than 5 min caused changes in cell morphology resulting in a distinctly spherical shape compared to untreated cells. In contrast, sodium cholate (SC) and CNT/SC did not affect cell morphology, proliferation, or growth. These data indicate that SC is an environmentally friendly surfactant for the purification and dispersion of SWCNTs. Epifluorescence microscopy analysis of CNT/DNA conjugates revealed distribution in the cytoplasm of cells and did not show adverse effects on cell morphology, proliferation, or viability during a 72-h incubation. These observations suggest that the SWCNTs could be used as non-viral vectors for diagnostic and therapeutic molecules across the blood-brain barrier to the brain and the central nervous system.

  6. alpha-Glucosidase-albumin conjugates: effect of chronic administration in mice

    International Nuclear Information System (INIS)

    Allen, T.M.; Murray, L.; Bhardwaj, D.; Poznansky, M.J.

    1985-01-01

    Enzyme albumin conjugates have been proposed as a means of increasing the efficacy of enzyme use in vivo and decreasing immune response to the enzyme. Particulate drug carriers, however, have a pronounced tendency to localize in the mononuclear phagocyte (reticuloendothelial) system. The authors have examined in mice the effect on phagocytic index, tissue distribution and organ size of continued administration of conjugates of alpha-glucosidase with either homologous or heterologous albumin. Mice received 10 X 2-mg injections of bovine serum albumin (BSA) or mouse serum albumin (MSA), either free, polymerized or conjugated with alpha-glucosidase. Experiments involving BSA had to be terminated before the end of the experiment because of anaphylaxis, but these reactions were less severe to the polymerized albumin than to free albumin. Free BSA, BSA polymer and BSA-enzyme conjugates all caused a decrease in phagocytic index after six injections. Mice receiving MSA showed no evidence of anaphylaxis, but mice receiving six or more injections of free MSA, MSA polymer or MSA-enzyme conjugate had significantly decreased phagocytic indices as compared to controls. Phagocytic indices had returned to normal by 7 days after the final injection. Tissue distribution of 125 I-labeled albumin preparations was determined in either naive or chronically injected mice

  7. Identification of quinone imine containing glutathione conjugates of diclofenac in rat bile.

    Science.gov (United States)

    Waldon, Daniel J; Teffera, Yohannes; Colletti, Adria E; Liu, Jingzhou; Zurcher, Danielle; Copeland, Katrina W; Zhao, Zhiyang

    2010-12-20

    High-resolution accurate MS with an LTQ-Orbitrap was used to identify quinone imine metabolites derived from the 5-hydroxy (5-OH) and 4 prime-hydroxy (4'-OH) glutathione conjugates of diclofenac in rat bile. The initial quinone imine metabolites formed by oxidation of diclofenac have been postulated to be reactive intermediates potentially involved in diclofenac-mediated hepatotoxicity; while these metabolites could be formed using in vitro systems, they have never been detected in vivo. This report describes the identification of secondary quinone imine metabolites derived from 5-OH and 4'-OH diclofenac glutathione conjugates in rat bile. To verify the proposed structures, the diclofenac quinone imine GSH conjugate standards were prepared synthetically and enzymatically. The novel metabolite peaks displayed the identical retention times, accurate mass MS/MS spectra, and the fragmentation patterns as the corresponding authentic standards. The formation of these secondary quinone metabolites occurs only under conditions where bile salt homeostasis was experimentally altered. Standard practice in biliary excretion experiments using bile duct-cannulated rats includes infusion of taurocholic acid and/or other bile acids to replace those lost due to continuous collection of bile; for this experiment, the rats received no replacement bile acid infusion. High-resolution accurate mass spectrometry data and comparison with chemically and enzymatically prepared quinone imines of diclofenac glutathione conjugates support the identification of these metabolites. A mechanism for the formation of these reactive quinone imine containing glutathione conjugates of diclofenac is proposed.

  8. Effect of Maillard Conjugates on the Physical Stability of Zein Nanoparticles Prepared by Liquid Antisolvent Coprecipitation.

    Science.gov (United States)

    Davidov-Pardo, Gabriel; Joye, Iris J; Espinal-Ruiz, Mauricio; McClements, David Julian

    2015-09-30

    Protein nanoparticles are often not very stable in a complex food matrix because they are primarily stabilized by electrostatic repulsion. In this study, we envisaged the stabilization of zein nanoparticles through Maillard conjugation reactions with polysaccharides of different molecular mass. Zein nanoparticles (0.5% w/v) containing resveratrol (0.025% w/v grape skin extract) were produced by liquid antisolvent precipitation and coated with Maillard conjugates (MC) of sodium caseinate and different molecular mass carbohydrates during particle production. Zein nanoparticles coated with conjugated polysaccharides of 2.8, 37, and 150 kDa had diameters of 198 ± 5, 176 ± 6, and 180 ± 3 nm, respectively. The encapsulation efficiency (∼83%) was not affected by conjugation, but the conjugates significantly improved particle stability against changes in pH (2.0-9.0), CaCl2 addition (up to 100 mM), and heat treatment (30-90 °C, 30 min). Zein nanoparticles coated by MC may therefore be suitable delivery systems for hydrophobic bioactive molecules in a wide range of commercial products.

  9. Multifunctional adhesive polymers: Preactivated thiolated chitosan-EDTA conjugates.

    Science.gov (United States)

    Netsomboon, Kesinee; Suchaoin, Wongsakorn; Laffleur, Flavia; Prüfert, Felix; Bernkop-Schnürch, Andreas

    2017-02-01

    The aim of this study was to synthesis preactivated thiolated chitosan-EDTA (Ch-EDTA-cys-2MNA) conjugates exhibiting in particular high mucoadhesive, cohesive and chelating properties. Thiol groups were coupled with chitosan by carbodiimide reaction and further preactivated by attachment with 2-mercaptonicotinic acid (2MNA) via disulfide bond formation. Determinations of primary amino and sulfhydryl groups were performed by TNBS and Ellman's tests, respectively. Cytotoxicity was screened by resazurin assay in Caco-2 cells. Mucoadhesive properties and bivalent cation binding capacity with Mg 2+ and Ca 2+ in comparison to chitosan-EDTA (Ch-EDTA) and thiolated Ch-EDTA (Ch-EDTA-cys) were evaluated. Determination of 2MNA and total sulfhydryl groups indicated that 80% of thiol groups were preactivated. The results from cytotoxicity studies demonstrated that Ch-EDTA-cys and Ch-EDTA-cys-2MNA were not toxic to the cells at the polymer test concentration of 0.25% (w/v) while cell viability decreased by increasing the concentration of Ch-EDTA. Although EDTA molecule was modified by thiolation and preactivation, approximately 50% of chelating properties of the conjugates were maintained compared to Ch-EDTA. Ch-EDTA-cys-2MNA adhered on freshly excised porcine intestinal mucosa up to 6h while Ch-EDTA adhered for just 1h. According to the combination of mucoadhesive and chelating properties of the conjugates synthesized in this study, Ch-EDTA-cys-2MNA might be useful for various mucosal drug delivery systems. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Numerical Modeling of Conjugate Heat Transfer in Fluid Network

    Science.gov (United States)

    Majumdar, Alok

    2004-01-01

    Fluid network modeling with conjugate heat transfer has many applications in Aerospace engineering. In modeling unsteady flow with heat transfer, it is important to know the variation of wall temperature in time and space to calculate heat transfer between solid to fluid. Since wall temperature is a function of flow, a coupled analysis of temperature of solid and fluid is necessary. In cryogenic applications, modeling of conjugate heat transfer is of great importance to correctly predict boil-off rate in propellant tanks and chill down of transfer lines. In TFAWS 2003, the present author delivered a paper to describe a general-purpose computer program, GFSSP (Generalized Fluid System Simulation Program). GFSSP calculates flow distribution in complex flow circuit for compressible/incompressible, with or without heat transfer or phase change in all real fluids or mixtures. The flow circuit constitutes of fluid nodes and branches. The mass, energy and specie conservation equations are solved at the nodes where as momentum conservation equations are solved at the branches. The proposed paper describes the extension of GFSSP to model conjugate heat transfer. The network also includes solid nodes and conductors in addition to fluid nodes and branches. The energy conservation equations for solid nodes solves to determine the temperatures of the solid nodes simultaneously with all conservation equations governing fluid flow. The numerical scheme accounts for conduction, convection and radiation heat transfer. The paper will also describe the applications of the code to predict chill down of cryogenic transfer line and boil-off rate of cryogenic propellant storage tank.

  11. Smaller Counter Cation for Higher Transconductance in Anionic Conjugated Polyelectrolytes

    KAUST Repository

    Schmidt, Martina M.

    2017-12-11

    Conjugated polyelectrolytes (CPEs) are a focus of research because combine their inherent electrical conductivity and the ability to interact with ions in aqueous solutions or biological systems. However, it is still not understood to what degree the counter ion in CPEs influences the properties of the CPE itself and the performance of electronic transducers. In order to investigate this, three different conjugated polyelectrolytes, poly(6-(thiophen-3-yl)hexane-1-sulfonate)s (PTHS−X+), are synthesized, which have the same polythiophene backbone but different X+ counter ions: the bulky tetrabutylammonium (TBA+), tetraethylammonium (TEA+), and the smallest tetramethylammonium (TMA+). At the interface with biological systems, thin CPE films have to be stable in an aqueous environment and should allow the inward and outward flow of ions from the electrolyte. Since the studied PTHS−X+ have different solubilities in water, the optical properties of pristine PTHS−X+ as well as of crosslinked PTHS−X+ via UV–vis absorption spectroscopy are investigated additionally. PTHS−TMA+ exhibits better aggregation, fast interdiffusion of ions, and fast recovery from the oxidized state. Additionally, spectroelectrochemical and cyclic voltammetric as well as electrochemical capacitance investigations show that PTHS−TMA+ can be oxidized to a higher degree. This leads to a better performance of PTHS−TMA+-based organic electrochemical transistors.

  12. Application of optical phase conjugation to plasma diagnostics (invited)

    International Nuclear Information System (INIS)

    Jahoda, F.C.; Anderson, B.T.; Forman, P.R.; Weber, P.G.

    1985-01-01

    Several possibilities for plasma diagnostics provided by optical phase conjugation and, in particular, self-pumped phase conjugation in barium titanate (BaTiO 3 ) are discussed. These include placing a plasma within a dye laser cavity equipped with a phase conjugate mirror for intracavity absorption measurements, time differential refractometry with high spatial resolution, and simplified real-time holographic interferometry. The principles of phase conjugation with particular reference to photorefractive media and the special advantages of self-pumped phase conjugation are reviewed prior to the discussion of the applications. Distinctions are made in the applications between those for which photorefractive conjugators are essential and those for which they only offer experimental simplification relative to other types of phase conjugators

  13. Niobium Pentachloride Activation of Enone Derivatives: Diels-Alder and Conjugate Addition Products

    Directory of Open Access Journals (Sweden)

    Gil Valdo José da Silva

    2002-05-01

    Full Text Available Niobium pentachloride has proven to be a powerful activating agent for Diels-Alder or conjugate addition reactions of cycloenones. The Diels-Alder product was obtained only with an unsubstituted enone (cyclohexenone and the highly reactive diene cyclopentadiene; substituents in the b-position of enones seem to prevent Diels-Alder reaction: oxygenated substituents favor the formation of vinyl chlorides (ethyl ether or dichloromethane as solvents or enol ethers (ethyl acetate as solvent, while a methyl substituent prevents any kind of transformation with NbCl5. Less reactive dienes, furan and 2-methylfuran gave the conjugate addition products of the furan ring to the enone system.

  14. Conjugate gradient filtering of instantaneous normal modes, saddles on the energy landscape, and diffusion in liquids.

    Science.gov (United States)

    Chowdhary, J; Keyes, T

    2002-02-01

    Instantaneous normal modes (INM's) are calculated during a conjugate-gradient (CG) descent of the potential energy landscape, starting from an equilibrium configuration of a liquid or crystal. A small number (approximately equal to 4) of CG steps removes all the Im-omega modes in the crystal and leaves the liquid with diffusive Im-omega which accurately represent the self-diffusion constant D. Conjugate gradient filtering appears to be a promising method, applicable to any system, of obtaining diffusive modes and facilitating INM theory of D. The relation of the CG-step dependent INM quantities to the landscape and its saddles is discussed.

  15. Necessary and sufficient conditions for the existence of a conjugate gradient method

    International Nuclear Information System (INIS)

    Faber, V.; Manteuffel, T.

    1984-01-01

    The authors characterize the class CG(s) of matrices A for which the linear system Ax = b can be solved by an s-term conjugate gradient method. The authors show that, except for a few anomalies, the class CG(s) consists of matrices A for which conjugate gradient methods are already known. These matrices are the Hermitian matrices, A* = A, and the matrices of the form A = e/sup i theta/(dI + B), with B* = -B. 7 references

  16. Antibody derivatization and conjugation strategies: application in preparation of stealth immunoliposome to target chemotherapeutics to tumor.

    Science.gov (United States)

    Manjappa, Arehalli S; Chaudhari, Kiran R; Venkataraju, Makam P; Dantuluri, Prudhviraju; Nanda, Biswarup; Sidda, Chennakesavulu; Sawant, Krutika K; Murthy, Rayasa S Ramachandra

    2011-02-28

    A great deal of effort has been made over the years to develop liposomes that have targeting vectors (oligosaccharides, peptides, proteins and vitamins) attached to the bilayer surface. Most studies have focused on antibody conjugates since procedures for producing highly specific monoclonal antibodies are well established. Antibody conjugated liposomes have recently attracted a great deal of interest, principally because of their potential use as targeted drug delivery systems and in diagnostic applications. A number of methods have been reported for coupling antibodies to the surface of stealth liposomes. The objective of this review is to enumerate various strategies which are employed in the modification and conjugation of antibodies to the surface of stealth liposomes. This review also describes various derivatization techniques of lipids prior and after their use in the preparation of liposomes. The use of single chain variable fragments and affibodies as targeting ligands in the preparation of immunoliposomes is also discussed. Copyright © 2010 Elsevier B.V. All rights reserved.

  17. Control of Helical Chirality of Ferrocene-Dipeptide Conjugates by the Secondary Structure of Dipeptide Chains.

    Science.gov (United States)

    Moriuchi, Toshiyuki; Nishiyama, Taiki; Nobu, Masaki; Hirao, Toshikazu

    2017-09-18

    Controlling helical chirality and creating protein secondary structures in cyclic/acyclic ferrocene-dipeptide bioorganometallic conjugates were achieved by adjusting the conformational flexibility of the dipeptide chains. In systems reported to date, the helical chirality of a conjugate was determined by the absolute configuration of the adjacent amino acid reside. In contrast, it was possible to induce both M- and P-helical chirality, even when the configuration of the adjacent amino acid was the same. It is particularly interesting to note that M-helical chirality was produced in a cyclic ferrocene-dipeptide conjugate composed of the l-Ala-d-Pro-cystamine-d-Pro-l-Ala dipeptide sequence (1), in which a type II β-turn-like secondary structure was established. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Cellular delivery and antisense effects of peptide nucleic acid conjugated to polyethyleneimine via disulfide linkers

    DEFF Research Database (Denmark)

    Berthold, Peter R; Shiraishi, Takehiko; Nielsen, Peter E

    2010-01-01

    Peptide nucleic acid (PNA) is potentially an attractive antisense and antigene agent for which more efficient cellular delivery systems are still warranted. The cationic polymer polyethylenimine (PEI) is commonly used for cellular transfection of DNA and RNA complexes, but is not readily applicable...... moiety) and further reacted this with a cysteine PNA. The level of modification was determined spectrophotometrically with high accuracy, and the PNA transfection efficiency of the conjugates was evaluated in an antisense luciferase splice-correction assay using HeLa pLuc705 cells. We find that PEI...... is an efficient vector for PNA delivery yielding significantly higher (up to 10-fold) antisense activity than an analogous PNA-octaarginine conjugate, even in the presence of chloroquine, which only slightly enhances the PEI-PNA activity. The PEI-PEG conjugates are preferred due to lower acute cellular toxicity...

  19. Application of conjugate gradient method to Commix-1B three-dimensional momentum equation

    International Nuclear Information System (INIS)

    King, J.B.; Domanus, H.

    1987-01-01

    Conjugate gradient method which is a special case of the variational method was implemented in the momentum section of the COMMIX-1B thermal hydraulics code. The comparisons between this method and the conventional iterative method of Successive Over Relation (S.O.R.) were made. Using COMMIX-1B, three steady state problems were analyzed. These problems were flow distribution in a scaled model of the Clinch River Fast Breeder Reactor outlet plenum, flow of coolant in the cold leg and downcomer of a PWR and isothermal air flow through a partially blocked pipe. It was found that if the conjugate gradient method is used, the execution time required to solve the resulting COMMIX-1B system of equations can be reduced by a factor of about 2 for the first two problems. For the isothermal air flow problem, the conjugate gradient method did not improve the execution time

  20. Functional Hybrid Biomaterials based on Peptide-Polymer Conjugates for Nanomedicine

    Science.gov (United States)

    Shu, Jessica Yo

    The focus of this dissertation is the design, synthesis and characterization of hybrid functional biomaterials based on peptide-polymer conjugates for nanomedicine. Generating synthetic materials with properties comparable to or superior than those found in nature has been a "holy grail" for the materials community. Man-made materials are still rather simplistic when compared to the chemical and structural complexity of a cell. Peptide-polymer conjugates have the potential to combine the advantages of the biological and synthetic worlds---that is they can combine the precise chemical structure and diverse functionality of biomolecules with the stability and processibility of synthetic polymers. As a new family of soft matter, they may lead to materials with novel properties that have yet to be realized with either of the components alone. In order for peptide-polymer conjugates to reach their full potential as useful materials, the structure and function of the peptide should be maintained upon polymer conjugation. The success in achieving desirable, functional assemblies relies on fundamentally understanding the interactions between each building block and delicately balancing and manipulating these interactions to achieve targeted assemblies without interfering with designed structures and functionalities. Such fundamental studies of peptide-polymer interactions were investigated as the nature of the polymer (hydrophilic vs. hydrophobic) and the site of its conjugation (end-conjugation vs. side-conjugation) were varied. The fundamental knowledge gained was then applied to the design of amphiphiles that self-assemble to form stable functional micelles. The micelles exhibited exceptional monodispersity and long-term stability, which is atypical of self-assembled systems. Thus such micelles based on amphiphilic peptide-polymer conjugates may meet many current demands in nanomedicine, in particular for drug delivery of hydrophobic anti-cancer therapeutics. Lastly

  1. Factors Affecting the Pharmacology of Antibody–Drug Conjugates

    Directory of Open Access Journals (Sweden)

    Andrew T. Lucas

    2018-02-01

    Full Text Available Major advances in therapeutic proteins, including antibody–drug conjugates (ADCs, have created revolutionary drug delivery systems in cancer over the past decade. While these immunoconjugate agents provide several advantages compared to their small-molecule counterparts, their clinical use is still in its infancy. The considerations in their development and clinical use are complex, and consist of multiple components and variables that can affect the pharmacologic characteristics. It is critical to understand the mechanisms employed by ADCs in navigating biological barriers and how these factors affect their biodistribution, delivery to tumors, efficacy, and toxicity. Thus, future studies are warranted to better understand the complex pharmacology and interaction between ADC carriers and biological systems, such as the mononuclear phagocyte system (MPS and tumor microenvironment. This review provides an overview of factors that affect the pharmacologic profiles of ADC therapies that are currently in clinical use and development.

  2. Stochastic Spectral and Conjugate Descent Methods

    KAUST Repository

    Kovalev, Dmitry

    2018-02-11

    The state-of-the-art methods for solving optimization problems in big dimensions are variants of randomized coordinate descent (RCD). In this paper we introduce a fundamentally new type of acceleration strategy for RCD based on the augmentation of the set of coordinate directions by a few spectral or conjugate directions. As we increase the number of extra directions to be sampled from, the rate of the method improves, and interpolates between the linear rate of RCD and a linear rate independent of the condition number. We develop and analyze also inexact variants of these methods where the spectral and conjugate directions are allowed to be approximate only. We motivate the above development by proving several negative results which highlight the limitations of RCD with importance sampling.

  3. Stochastic Spectral and Conjugate Descent Methods

    KAUST Repository

    Kovalev, Dmitry; Gorbunov, Eduard; Gasanov, Elnur; Richtarik, Peter

    2018-01-01

    The state-of-the-art methods for solving optimization problems in big dimensions are variants of randomized coordinate descent (RCD). In this paper we introduce a fundamentally new type of acceleration strategy for RCD based on the augmentation of the set of coordinate directions by a few spectral or conjugate directions. As we increase the number of extra directions to be sampled from, the rate of the method improves, and interpolates between the linear rate of RCD and a linear rate independent of the condition number. We develop and analyze also inexact variants of these methods where the spectral and conjugate directions are allowed to be approximate only. We motivate the above development by proving several negative results which highlight the limitations of RCD with importance sampling.

  4. Phase-conjugate optical coherence tomography

    International Nuclear Information System (INIS)

    Erkmen, Baris I.; Shapiro, Jeffrey H.

    2006-01-01

    Quantum optical coherence tomography (Q-OCT) offers a factor-of-2 improvement in axial resolution and the advantage of even-order dispersion cancellation when it is compared to conventional OCT (C-OCT). These features have been ascribed to the nonclassical nature of the biphoton state employed in the former, as opposed to the classical state used in the latter. Phase-conjugate OCT (PC-OCT) shows that nonclassical light is not necessary to reap Q-OCT's advantages. PC-OCT uses classical-state signal and reference beams, which have a phase-sensitive cross correlation, together with phase conjugation to achieve the axial resolution and even-order dispersion cancellation of Q-OCT with a signal-to-noise ratio that can be comparable to that of C-OCT

  5. Antibody conjugate radioimmunotherapy of superficial bladder cancer

    International Nuclear Information System (INIS)

    Perkins, Alan; Hopper, Melanie; Murray, Andrea; Frier, Malcolm; Bishop, Mike

    2002-01-01

    The administration of antibody conjugates for cancer therapy is now proving to be of clinical value. We are currently undertaking a programme of clinical studies using the monoclonal antibody C 595 (gG3) which reacts with the MUC1 glycoprotein antigen that is aberrantly expressed in a high proportion of bladder tumours. Radio immuno conjugates of the C 595 antibody have been produced with high radiolabelling efficiency and immuno reactivity using Tc-99 m and In-111 for diagnostic imaging, and disease staging and the cytotoxic radionuclides Cu-67 and Re-188 for therapy of superficial bladder cancer. A Phase I/II therapeutic trail involving the intravesical administration of antibody directly into the bladder has now begun. (author)

  6. High-mobility group box 1 released by autophagic cancer-associated fibroblasts maintains the stemness of luminal breast cancer cells.

    Science.gov (United States)

    Zhao, Xi-Long; Lin, Yong; Jiang, Jun; Tang, Zhuo; Yang, Shuai; Lu, Lu; Liang, Yan; Liu, Xue; Tan, Jiao; Hu, Xu-Gang; Niu, Qin; Fu, Wen-Juan; Yan, Ze-Xuan; Guo, De-Yu; Ping, Yi-Fang; Wang, Ji Ming; Zhang, Xia; Kung, Hsiang-Fu; Bian, Xiu-Wu; Yao, Xiao-Hong

    2017-11-01

    Cancer stem cells/cancer-initiating cells (CICs) and their microenvironmental niche play a vital role in malignant tumour recurrence and metastasis. Cancer-associated fibroblasts (CAFs) are major components of the niche of breast cancer-initiating cells (BCICs), and their interactions may profoundly affect breast cancer progression. Autophagy has been considered to be a critical process for CIC maintenance, but whether it is involved in the cross-talk between CAFs and CICs to affect tumourigenesis and pathological significance has not been determined. In this study, we found that the presence of CAFs containing high levels of microtubule-associated protein 1 light chain 3 (LC3II), a marker of autophagosomes, was associated with more aggressive luminal human breast cancer. CAFs in human luminal breast cancer tissues with high autophagy activity enriched BCICs with increased tumourigenicity. Mechanistically, autophagic CAFs released high-mobility group box 1 (HMGB1), which activated its receptor, Toll-like receptor (TLR) 4, expressed by luminal breast cancer cells, to enhance their stemness and tumourigenicity. Furthermore, immunohistochemistry of 180 luminal breast cancers revealed that high LC3II/TLR4 levels predicted an increased relapse rate and a poorer prognosis. Our findings demonstrate that autophagic CAFs play a critical role in promoting the progression of luminal breast cancer through an HMGB1-TLR4 axis, and that both autophagy in CAFs and TLR4 on breast cancer cells constitute potential therapeutic targets. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

  7. KrF laser amplifier with phase-conjugate Brillouin retroreflectors.

    Science.gov (United States)

    Gower, M C

    1982-09-01

    We have demonstrated the use of phase-conjugate stimulated Brillouin scattering mirrors to produce high-quality, short-pulse KrF laser beams from angular multiplexed and regenerative amplifiers. The mirror was also shown to isolate systems optically from amplifier spontaneous emission. Automatic alignment of targets using this mirror as a retroreflector was also demonstrated.

  8. Spectroscopic Investigation of the Ultrafast Photoinduced Dynamics in pi-Conjugated Terpyridines

    NARCIS (Netherlands)

    Siebert, R.; Akimov, D.; Schmitt, M.; Winter, A.; Schubert, U.S.; Dietzek, B.; Popp, J.

    2009-01-01

    Time-resolved spectroscopy is applied to investigate the ultrafast relaxation dynamics of several pi-conjugated mono-, bis-, tris- and tetrakis(terpyridine) derivs. This particular series of structurally closely related systems was prepd. applying efficient synthetic strategies and resembles key

  9. Two-level preconditioned conjugate gradient methods with applications to bubbly flow problems

    NARCIS (Netherlands)

    Tang, J.M.

    2008-01-01

    The Preconditioned Conjugate Gradient (PCG) method is one of the most popular iterative methods for solving large linear systems with a symmetric and positive semi-definite coefficient matrix. However, if the preconditioned coefficient matrix is ill-conditioned, the convergence of the PCG method

  10. A VAR2CSA:CSP conjugate capable of inducing dual specificity ...

    African Journals Online (AJOL)

    Background: Vaccine antigens targeting specific P. falciparum parasite stages are under pre-clinical and clinical development. It seems plausible that vaccine with multiple specificities will offer higher protection. With this hypothesis, we exploited the Spy- Tag/SpyCatcher conjugation system to make a, post expression, dual ...

  11. An M-step preconditioned conjugate gradient method for parallel computation

    Science.gov (United States)

    Adams, L.

    1983-01-01

    This paper describes a preconditioned conjugate gradient method that can be effectively implemented on both vector machines and parallel arrays to solve sparse symmetric and positive definite systems of linear equations. The implementation on the CYBER 203/205 and on the Finite Element Machine is discussed and results obtained using the method on these machines are given.

  12. Analysis and performance estimation of the Conjugate Gradient method on multiple GPUs

    NARCIS (Netherlands)

    Verschoor, M.; Jalba, A.C.

    2012-01-01

    The Conjugate Gradient (CG) method is a widely-used iterative method for solving linear systems described by a (sparse) matrix. The method requires a large amount of Sparse-Matrix Vector (SpMV) multiplications, vector reductions and other vector operations to be performed. We present a number of

  13. Separation of metronidazole, its major metabolites and their conjugates using dynamically modified silica

    DEFF Research Database (Denmark)

    Thomsen, U. G.; Cornett, Claus; Tjornelund, J.

    1995-01-01

    -performance liquid chromatographic (HPLC) system for the simultaneous determination of metronidazole, its major metabolites and their glucuronic acid conjugates in biological fluids. The separation is performed using bare silica dynamically modified with N-cetyl-N,N,N-trimethylammonium bromide contained...

  14. ADRIAMYCIN-LOADED ALBUMIN-HEPARIN CONJUGATE MICROSPHERES FOR INTRAPERITONEAL CHEMOTHERAPY

    NARCIS (Netherlands)

    CREMERS, HFM; SEYMOUR, LW; LAM, K; LOS, G; KWON, G; BAE, YH; KIM, SW; FEIJEN, J

    1994-01-01

    Adriamycin-loaded albumin-heparin conjugate microspheres (ADR-AHCMS) were evaluated as possible intraperitoneal (i.p.) delivery systems for site-specific cytotoxic action. The biocompatibility of the microspheres after intraperitoneal injection was tested first. 1 day after i.p. administration of

  15. SXT/R391 Integrative and Conjugative Elements (ICEs) Encode a Novel 'Trap-Door' Strategy for Mobile Element Escape.

    Science.gov (United States)

    Ryan, Michael P; Armshaw, Patricia; Pembroke, J Tony

    2016-01-01

    Integrative conjugative elements (ICEs) are a class of bacterial mobile elements that have the ability to mediate their own integration, excision, and transfer from one host genome to another by a mechanism of site-specific recombination, self-circularisation, and conjugative transfer. Members of the SXT/R391 ICE family of enterobacterial mobile genetic elements display an unusual UV-inducible sensitization function which results in stress induced killing of bacterial cells harboring the ICE. This sensitization has been shown to be associated with a stress induced overexpression of a mobile element encoded conjugative transfer gene, orf43, a traV homolog. This results in cell lysis and release of a circular form of the ICE. Induction of this novel system may allow transfer of an ICE, enhancing its survival potential under conditions not conducive to conjugative transfer.

  16. Improved cellular uptake of antisense Peptide nucleic acids by conjugation to a cell-penetrating Peptide and a lipid domain

    DEFF Research Database (Denmark)

    Shiraishi, Takehiko; Nielsen, Peter E

    2011-01-01

    based on a splicing correction of a mutated luciferase gene in HeLa pLuc705 cells by targeting antisense oligonucleotides to a cryptic splice site. Further improvement in the delivery of CatLip-PNA conjugates is achieved by using auxiliary agents/treatments (e.g., chloroquine, calcium ions......Unaided cellular uptake of RNA interference agents such as antisense oligonucleotides and siRNA is extremely poor, and in vivo bioavailability is also limited. Thus, effective delivery strategies for such potential drugs are in high demand. Recently, a novel approach using a class of short cationic....... We have found, however, that this low -bioavailability can be significantly improved by chemical conjugation to a lipid domain ("Lip," such as a fatty acid), thereby creating "CatLip"-conjugates. The cellular uptake of these conjugates is conveniently evaluated using a sensitive cellular assay system...

  17. Error Estimation in Preconditioned Conjugate Gradients

    Czech Academy of Sciences Publication Activity Database

    Strakoš, Zdeněk; Tichý, Petr

    2005-01-01

    Roč. 45, - (2005), s. 789-817 ISSN 0006-3835 R&D Projects: GA AV ČR 1ET400300415; GA AV ČR KJB1030306 Institutional research plan: CEZ:AV0Z10300504 Keywords : preconditioned conjugate gradient method * error bounds * stopping criteria * evaluation of convergence * numerical stability * finite precision arithmetic * rounding errors Subject RIV: BA - General Mathematics Impact factor: 0.509, year: 2005

  18. Conjugate gradient optimization programs for shuttle reentry

    Science.gov (United States)

    Powers, W. F.; Jacobson, R. A.; Leonard, D. A.

    1972-01-01

    Two computer programs for shuttle reentry trajectory optimization are listed and described. Both programs use the conjugate gradient method as the optimization procedure. The Phase 1 Program is developed in cartesian coordinates for a rotating spherical earth, and crossrange, downrange, maximum deceleration, total heating, and terminal speed, altitude, and flight path angle are included in the performance index. The programs make extensive use of subroutines so that they may be easily adapted to other atmospheric trajectory optimization problems.

  19. [Relationship between family variables and conjugal adjustment].

    Science.gov (United States)

    Jiménez-Picón, Nerea; Lima-Rodríguez, Joaquín-Salvador; Lima-Serrano, Marta

    2018-04-01

    To determine whether family variables, such as type of relationship, years of marriage, existence of offspring, number of members of family, stage of family life cycle, transition between stages, perceived social support, and/or stressful life events are related to conjugal adjustment. A cross-sectional and correlational study using questionnaires. Primary care and hospital units of selected centres in the province of Seville, Spain. Consecutive stratified sampling by quotas of 369 heterosexual couples over 18years of age, who maintained a relationship, with or without children, living in Seville. A self-report questionnaire for the sociodemographic variables, and the abbreviated version of the Dyadic Adjustment Scale, Questionnaire MOS Perceived Social Support, and Social Readjustment Rating Scale, were used. Descriptive and inferential statistics were performed with correlation analysis and multivariate regression. Statistically significant associations were found between conjugal adjustment and marriage years (r=-10: Pfamily life cycle (F=2.65; Pfamily life cycle stage (mature-aged stage) on conjugal adjustment (R2=.21; F=9.9; df=356; Prelationship. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

  20. Cancer Chemopreventive Ability of Conjugated Linolenic Acids

    Directory of Open Access Journals (Sweden)

    Kazuo Miyashita

    2011-11-01

    Full Text Available Conjugated fatty acids (CFA have received increased interest because of their beneficial effects on human health, including preventing cancer development. Conjugated linoleic acids (CLA are such CFA, and have been reviewed extensively for their multiple biological activities. In contrast to other types of CFAs including CLA that are found at low concentrations (less than 1% in natural products, conjugated linolenic acids (CLN are the only CFAs that occur in higher quantities in natural products. Some plant seeds contain a considerably high concentration of CLN (30 to 70 wt% lipid. Our research group has screened CLN from different plant seed oils to determine their cancer chemopreventive ability. This review describes the physiological functions of CLN isomers that occur in certain plant seeds. CLN are able to induce apoptosis through decrease of Bcl-2 protein in certain human cancer cell lines, increase expression of peroxisome proliferator-activated receptor (PPAR-γ, and up-regulate gene expression of p53. Findings in our preclinical animal studies have indicated that feeding with CLN resulted in inhibition of colorectal tumorigenesis through modulation of apoptosis and expression of PPARγ and p53. In this review, we summarize chemopreventive efficacy of CLN against cancer development, especially colorectal cancer.

  1. Nanodiamond-DGEA peptide conjugates for enhanced delivery of doxorubicin to prostate cancer

    Directory of Open Access Journals (Sweden)

    Amanee D Salaam

    2014-07-01

    Full Text Available The field of nanomedicine has emerged as an approach to enhance the specificity and efficacy of cancer treatments as stand-alone therapies and in combination with standard chemotherapeutic treatment regimens. The current standard of care for metastatic cancer, doxorubicin (DOX, is presented with challenges, namely toxicity due to a lack of specificity and targeted delivery. Nano-enabled targeted drug delivery systems can provide an avenue to overcome these issues. Nanodiamonds (ND, in particular, have been researched over the past five years for use in various drug delivery systems but minimal work has been done that incorporates targeting capability. In this study, a novel targeted drug delivery system for bone metastatic prostate cancer was developed, characterized, and evaluated in vitro. NDs were conjugated with the Asp–Gly–Glu–Ala (DGEA peptide to target α2β1 integrins over-expressed in prostate cancers during metastasis. To facilitate drug delivery, DOX was adsorbed to the surface of the ND-DGEA conjugates. Successful preparation of the ND-DGEA conjugates and the ND-DGEA+DOX system was confirmed with transmission electron microscopy, hydrodynamic size, and zeta potential measurements. Since traditional DOX treatment regimens lack specificity and increased toxicity to normal tissues, the ND-DGEA conjugates were designed to distinguish between cells that overexpress α2β1 integrin, bone metastatic prostate cancers cells (PC3, and cells that do not, human mesenchymal stem cells (hMSC. Utilizing the ND-DGEA+DOX system, the efficacy of 1 µg/mL and 2 µg/mL DOX doses increased from 2.5% to 12% cell death and 11% to 34% cell death, respectively. These studies confirmed that the delivery and efficacy of DOX were enhanced by ND-DGEA conjugates. Thus, the targeted ND-DGEA+DOX system provides a novel approach for decreasing toxicity and drug doses.

  2. Concanavalin A conjugated biodegradable nanoparticles for oral insulin delivery

    Science.gov (United States)

    Hurkat, Pooja; Jain, Aviral; Jain, Ashish; Shilpi, Satish; Gulbake, Arvind; Jain, Sanjay K.

    2012-11-01

    Major research issues in oral protein delivery include the stabilization of protein in delivery devices which could increase its oral bioavailability. The study deals with development of oral insulin delivery system utilizing biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and modifying its surface with Concanavalin A to increase lymphatic uptake. Surface-modified PLGA nanoparticles were characterized for conjugation efficiency of ligand, shape and surface morphology, particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro drug release. Stability of insulin in the developed formulation was confirmed by SDS-PAGE, and integrity of entrapped insulin was assessed using circular dichroism spectrum. Ex vivo study was performed on Wistar rats, which exhibited the higher intestinal uptake of Con A conjugated nanoparticles. In vivo study performed on streptozotocin-induced diabetic rats which indicate that a surface-modified nanoparticle reduces blood glucose level effectively within 4 h of its oral administration. In conclusion, the present work resulted in successful production of Con A NPs bearing insulin with sustained release profile, and better absorption and stability. The Con A NPs showed high insulin uptake, due to its relative high affinity for non-reducing carbohydrate residues i.e., fucose present on M cells and have the potential for oral insulin delivery in effective management of Type 1 diabetes condition.

  3. Guanidinylated Neomycin Conjugation Enhances Intranasal Enzyme Replacement in the Brain.

    Science.gov (United States)

    Tong, Wenyong; Dwyer, Chrissa A; Thacker, Bryan E; Glass, Charles A; Brown, Jillian R; Hamill, Kristina; Moremen, Kelley W; Sarrazin, Stéphane; Gordts, Philip L S M; Dozier, Lara E; Patrick, Gentry N; Tor, Yitzhak; Esko, Jeffrey D

    2017-12-06

    Iduronidase (IDUA)-deficient mice accumulate glycosaminoglycans in cells and tissues and exhibit many of the same neuropathological symptoms of patients suffering from Mucopolysaccharidosis I. Intravenous enzyme-replacement therapy for Mucopolysaccharidosis I ameliorates glycosaminoglycan storage and many of the somatic aspects of the disease but fails to treat neurological symptoms due to poor transport across the blood-brain barrier. In this study, we examined the delivery of IDUA conjugated to guanidinoneomycin (GNeo), a molecular transporter. GNeo-IDUA and IDUA injected intravenously resulted in reduced hepatic glycosaminoglycan accumulation but had no effect in the brain due to fast clearance from the circulation. In contrast, intranasally administered GNeo-IDUA entered the brain rapidly. Repetitive intranasal treatment with GNeo-IDUA reduced glycosaminoglycan storage, lysosome size and number, and neurodegenerative astrogliosis in the olfactory bulb and primary somatosensory cortex, whereas IDUA was less effective. The enhanced efficacy of GNeo-IDUA was not the result of increased nose-to-brain delivery or enzyme stability, but rather due to more efficient uptake into neurons and astrocytes. GNeo conjugation also enhanced glycosaminoglycan clearance by intranasally delivered sulfamidase to the brain of sulfamidase-deficient mice, a model of Mucopolysaccharidosis IIIA. These findings suggest the general utility of the guanidinoglycoside-based delivery system for restoring missing lysosomal enzymes in the brain. Copyright © 2017 The American Society of Gene and Cell Therapy. Published by Elsevier Inc. All rights reserved.

  4. Genetic engineering and chemical conjugation of potato virus X.

    Science.gov (United States)

    Lee, Karin L; Uhde-Holzem, Kerstin; Fischer, Rainer; Commandeur, Ulrich; Steinmetz, Nicole F

    2014-01-01

    Here we report the genetic engineering and chemical modification of potato virus X (PVX) for the presentation of various peptides, proteins, and fluorescent dyes, or other chemical modifiers. Three different ways of genetic engineering are described and by these means, peptides are successfully expressed not only when the foot and mouth disease virus (FMDV) 2A sequence or a flexible glycine-serine linker is included, but also when the peptide is fused directly to the PVX coat protein. When larger proteins or unfavorable peptide sequences are presented, a partial fusion via the FMDV 2A sequence is preferable. When these PVX chimeras retain the ability to assemble into viral particles and are thus able to infect plants systemically, they can be utilized to inoculate susceptible plants for isolation of sufficient amounts of virus particles for subsequent chemical modification. Chemical modification is required for the display of nonbiological ligands such as fluorophores, polymers, and small drug compounds. We present three methods of chemical bioconjugation. For direct conjugation of small chemical modifiers to solvent exposed lysines, N-hydroxysuccinimide chemistry can be applied. Bio-orthogonal reactions such as copper-catalyzed azide-alkyne cycloaddition or hydrazone ligation are alternatives to achieve more efficient conjugation (e.g., when working with high molecular weight or insoluble ligands). Furthermore, hydrazone ligation offers an attractive route for the introduction of pH-cleavable cargos (e.g., therapeutic molecules).

  5. Concanavalin A conjugated biodegradable nanoparticles for oral insulin delivery

    Energy Technology Data Exchange (ETDEWEB)

    Hurkat, Pooja; Jain, Aviral; Jain, Ashish; Shilpi, Satish; Gulbake, Arvind; Jain, Sanjay K., E-mail: drskjainin@yahoo.com [Dr. Hari Singh Gour Vishwavidyalaya, Pharmaceutics Research Projects Laboratory, Department of Pharmaceutical Sciences (India)

    2012-11-15

    Major research issues in oral protein delivery include the stabilization of protein in delivery devices which could increase its oral bioavailability. The study deals with development of oral insulin delivery system utilizing biodegradable poly(lactic-co-glycolic acid) (PLGA) nanoparticles and modifying its surface with Concanavalin A to increase lymphatic uptake. Surface-modified PLGA nanoparticles were characterized for conjugation efficiency of ligand, shape and surface morphology, particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro drug release. Stability of insulin in the developed formulation was confirmed by SDS-PAGE, and integrity of entrapped insulin was assessed using circular dichroism spectrum. Ex vivo study was performed on Wistar rats, which exhibited the higher intestinal uptake of Con A conjugated nanoparticles. In vivo study performed on streptozotocin-induced diabetic rats which indicate that a surface-modified nanoparticle reduces blood glucose level effectively within 4 h of its oral administration. In conclusion, the present work resulted in successful production of Con A NPs bearing insulin with sustained release profile, and better absorption and stability. The Con A NPs showed high insulin uptake, due to its relative high affinity for non-reducing carbohydrate residues i.e., fucose present on M cells and have the potential for oral insulin delivery in effective management of Type 1 diabetes condition.

  6. Material Selection for Microchannel Heatsink: Conjugate Heat Transfer Simulation

    Science.gov (United States)

    Uday Kumar, A.; Javed, Arshad; Dubey, Satish K.

    2018-04-01

    Heat dissipation during the operation of electronic devices causes rise in temperature, which demands an effective thermal management for their performance, life and reliability. Single phase liquid cooling in microchannels is an effective and proven technology for electronics cooling. However, due to the ongoing trends of miniaturization and developments in the microelectronics technology, the future needs of heat flux dissipation rate are expected to rise to 1 kW/cm2. Air cooled systems are unable to meet this demand. Hence, liquid cooled heatsinks are preferred. This paper presents conjugate heat transfer simulation of single phase flow in microchannels with application to electronic cooling. The numerical model is simulated for different materials: copper, aluminium and silicon as solid and water as liquid coolant. The performances of microchannel heatsink are analysed for mass flow rate range of 20-40 ml/min. The investigation has been carried out on same size of electronic chip and heat flux in order to have comparative study of different materials. This paper is divided into two sections: fabrication techniques and numerical simulation for different materials. In the first part, a brief discussion of fabrication techniques of microchannel heatsink have been presented. The second section presents conjugate heat transfer simulation and parametric investigation for different material microchannel heatsink. The presented study and findings are useful for selection of materials for microchannel heatsink.

  7. Fluorescent nanodiamond-bacteriophage conjugates maintain host specificity.

    Science.gov (United States)

    Trinh, Jimmy T; Alkahtani, Masfer H; Rampersaud, Isaac; Rampersaud, Arfaan; Scully, Marlan; Young, Ryland F; Hemmer, Philip; Zeng, Lanying

    2018-06-01

    Rapid identification of specific bacterial strains within clinical, environmental, and food samples can facilitate the prevention and treatment of disease. Fluorescent nanodiamonds (FNDs) are being developed as biomarkers in biology and medicine, due to their excellent imaging properties, ability to accept surface modifications, and lack of toxicity. Bacteriophages, the viruses of bacteria, can have exquisite specificity for certain hosts. We propose to exploit the properties of FNDs and phages to develop phages conjugated with FNDs as long-lived fluorescent diagnostic reagents. In this study, we develop a simple procedure to create such fluorescent probes by functionalizing the FNDs and phages with streptavidin and biotin, respectively. We find that the FND-phage conjugates retain the favorable characteristics of the individual components and can discern their proper host within a mixture. This technology may be further explored using different phage/bacteria systems, different FND color centers and alternate chemical labeling schemes for additional means of bacterial identification and new single-cell/virus studies. © 2018 Wiley Periodicals, Inc.

  8. Context Dependent Effects of Chimeric Peptide Morpholino Conjugates Contribute to Dystrophin Exon-skipping Efficiency.

    Science.gov (United States)

    Yin, Haifang; Boisguerin, Prisca; Moulton, Hong M; Betts, Corinne; Seow, Yiqi; Boutilier, Jordan; Wang, Qingsong; Walsh, Anthony; Lebleu, Bernard; Wood, Matthew Ja

    2013-09-24

    We have recently reported that cell-penetrating peptides (CPPs) and novel chimeric peptides containing CPP (referred as B peptide) and muscle-targeting peptide (referred as MSP) motifs significantly improve the systemic exon-skipping activity of morpholino phosphorodiamidate oligomers (PMOs) in dystrophin-deficient mdx mice. In the present study, the general mechanistic significance of the chimeric peptide configuration on the activity and tissue uptake of peptide conjugated PMOs in vivo was investigated. Four additional chimeric peptide-PMO conjugates including newly identified peptide 9 (B-9-PMO and 9-B-PMO) and control peptide 3 (B-3-PMO and 3-B-PMO) were tested in mdx mice. Immunohistochemical staining, RT-PCR and western blot results indicated that B-9-PMO induced significantly higher level of exon skipping and dystrophin restoration than its counterpart (9-B-PMO), further corroborating the notion that the activity of chimeric peptide-PMO conjugates is dependent on relative position of the tissue-targeting peptide motif within the chimeric peptide with respect to PMOs. Subsequent mechanistic studies showed that enhanced cellular uptake of B-MSP-PMO into muscle cells leads to increased exon-skipping activity in comparison with MSP-B-PMO. Surprisingly, further evidence showed that the uptake of chimeric peptide-PMO conjugates of both orientations (B-MSP-PMO and MSP-B-PMO) was ATP- and temperature-dependent and also partially mediated by heparan sulfate proteoglycans (HSPG), indicating that endocytosis is likely the main uptake pathway for both chimeric peptide-PMO conjugates. Collectively, our data demonstrate that peptide orientation in chimeric peptides is an important parameter that determines cellular uptake and activity when conjugated directly to oligonucleotides. These observations provide insight into the design of improved cell targeting compounds for future therapeutics studies.Molecular Therapy-Nucleic Acids (2013) 2, e124; doi:10.1038/mtna.2013

  9. N-succinyl-chitosan as a drug carrier: water-insoluble and water-soluble conjugates.

    Science.gov (United States)

    Kato, Yoshinori; Onishi, Hiraku; Machida, Yoshiharu

    2004-02-01

    N-succinyl-chitosan (Suc-Chi) has favourable properties as a drug carrier such as biocompatibility, low toxicity and long-term retention in the body. It was long retained in the systemic circulation after intravenous administration, and the plasma half-lives of Suc-Chi (MW: 3.4 x 10(5); succinylation degree: 0.81 mol/sugar unit; deacetylation degree: 1.0 mol/sugar unit) were ca. 100.3h in normal mice and 43 h in Sarcoma 180-bearing mice. The biodistribution of Suc-Chi into other tissues was trace apart from the prostate and lymph nodes. The maximum tolerable dose for the intraperitoneal injection of Suc-Chi to mice was greater than 2 g/kg. The water-insoluble and water-soluble conjugates could be prepared using a water-soluble carbodiimide and mitomycin C (MMC) or using an activated ester of glutaric MMC. In vitro release characteristics of these conjugates showed similar patterns, i.e. a pH-dependent manner, except that water-insoluble conjugates showed a slightly slower release of MMC than water-soluble ones. The conjugates of MMC with Suc-Chi showed good antitumour activities against various tumours such as murine leukaemias (L1210 and P388), B16 melanoma, Sarcoma 180 solid tumour, a murine liver metastatic tumour (M5076) and a murine hepatic cell carcinoma (MH134). This review summarizes the utilization of Suc-Chi as a drug carrier for macromolecular conjugates of MMC and the therapeutic efficacy of the conjugates against various tumours.

  10. Context Dependent Effects of Chimeric Peptide Morpholino Conjugates Contribute to Dystrophin Exon-skipping Efficiency

    Directory of Open Access Journals (Sweden)

    HaiFang Yin

    2013-01-01

    Full Text Available We have recently reported that cell-penetrating peptides (CPPs and novel chimeric peptides containing CPP (referred as B peptide and muscle-targeting peptide (referred as MSP motifs significantly improve the systemic exon-skipping activity of morpholino phosphorodiamidate oligomers (PMOs in dystrophin-deficient mdx mice. In the present study, the general mechanistic significance of the chimeric peptide configuration on the activity and tissue uptake of peptide conjugated PMOs in vivo was investigated. Four additional chimeric peptide-PMO conjugates including newly identified peptide 9 (B-9-PMO and 9-B-PMO and control peptide 3 (B-3-PMO and 3-B-PMO were tested in mdx mice. Immunohistochemical staining, RT-PCR and western blot results indicated that B-9-PMO induced significantly higher level of exon skipping and dystrophin restoration than its counterpart (9-B-PMO, further corroborating the notion that the activity of chimeric peptide-PMO conjugates is dependent on relative position of the tissue-targeting peptide motif within the chimeric peptide with respect to PMOs. Subsequent mechanistic studies showed that enhanced cellular uptake of B-MSP-PMO into muscle cells leads to increased exon-skipping activity in comparison with MSP-B-PMO. Surprisingly, further evidence showed that the uptake of chimeric peptide-PMO conjugates of both orientations (B-MSP-PMO and MSP-B-PMO was ATP- and temperature-dependent and also partially mediated by heparan sulfate proteoglycans (HSPG, indicating that endocytosis is likely the main uptake pathway for both chimeric peptide-PMO conjugates. Collectively, our data demonstrate that peptide orientation in chimeric peptides is an important parameter that determines cellular uptake and activity when conjugated directly to oligonucleotides. These observations provide insight into the design of improved cell targeting compounds for future therapeutics studies.

  11. NIR photoregulated chemo- and photodynamic cancer therapy based on conjugated polyelectrolyte-drug conjugate encapsulated upconversion nanoparticles

    Science.gov (United States)

    Yuan, Youyong; Min, Yuanzeng; Hu, Qinglian; Xing, Bengang; Liu, Bin

    2014-09-01

    The design of nanoplatforms with target recognition and near-infrared (NIR) laser photoregulated chemo- and photodynamic therapy is highly desirable but remains challenging. In this work, we have developed such a system by taking advantage of a conjugated polyelectrolyte (CPE)-drug conjugate and upconversion nanoparticles (UCNPs). The poly(ethylene glycol) (PEG) grafted CPE not only serves as a polymer matrix for UCNP encapsulation, but also as a fluorescent imaging agent, a photosensitizer as well as a carrier for chemotherapeutic drug doxorubicin (DOX) through a UV-cleavable ortho-nitrobenzyl (NB) linker. Upon 980 nm laser irradiation, the UCNPs emit UV and visible light. The up-converted UV light is utilized for controlled drug release through the photocleavage of the ortho-nitrobenzyl linker, while the up-converted visible light is used to initiate the polymer photosensitizer to produce reactive oxygen species (ROS) for photodynamic therapy. The NIR photo-regulated UCNP@CPE-DOX showed high efficiency of ROS generation and controlled drug release in cancer cells upon single laser irradiation. In addition, the combination therapy showed enhanced inhibition of U87-MG cell growth as compared to sole treatments. As two light sources with different wavelengths are always needed for traditional photodynamic therapy and photoregulated drug release, the adoption of UCNPs as an NIR light switch is highly beneficial to combined chemo- and photodynamic therapy with enhanced therapeutic effects.

  12. Dye linked conjugated homopolymers: using conjugated polymer electroluminescence to optically pump porphyrin-dye emission

    DEFF Research Database (Denmark)

    Nielsen, K.T.; Spanggaard, H.; Krebs, Frederik C

    2004-01-01

    . Electroluminescent devices of the homopolymer itself and of the zinc-porphyrin containing polymer were prepared and the nature of the electroluminescence was characterized. The homopolymer segments were found to optically pump the emission of the zinc-porphyrin dye moities. The homopolymer exhibits blue......Zinc-porphyrin dye molecules were incorporated into the backbone of a conjugated polymer material by a method, which allowed for the incorporation of only one zinc-porphyrin dye molecule into the backbone of each conjugated polymer molecule. The electronic properties of the homopolymer were...

  13. Role of Many-Body Effects in Describing Low-Lying Excited States of pi-Conjugated Chromophores: High-Level Equation-of-Motion Coupled-Cluster Studies of Fused Porphyrin Systems

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, Karol; Olson, Ryan M.; Krishnamoorthy, Sriram; Tipparaju, Vinod; Apra, Edoardo

    2011-07-12

    The unusual photophysical properties of the pi-conjugated chrompohores makes them potential building blocks of various molecular devices. In particular, significant narrowing of the HOMO-LUMO gaps can be observed as an effect of functionalization chromophores with polycyclic aromatic hydrocabrons (PAHs). In this paper we present equation-of-motion coupled cluster calculations for vertical excitation energies of several functionalized forms of porphyrins. The results of free-base porphyrin (FBP) clearly demonstrate significant differences between functionalization of FBP with one- (anthracene) and two-dimensional (coronene) structures. We also compare the EOMCC results with the experimentally available results for the anthracene fused zinc porphyrin. The impact of various-type correlation effects is illustrated on several benchmark models where the comparison with the experiment is possible. In particular, we demonstrate that for all excited states considered in this paper, all of them being dominated by single excitations, the inclusion of triply excited configurations is crucial for attaining qualitative agreement with the experiment. We also demonstrate the parallel performance of the most computationally intensive part of the completely renormalized EOMCCSD(T) approach (CR-EOMCCSD(T)) across 120,000 cores.

  14. The role of many-body effects in describing low-lying excited states of pi-conjugated chromophores: high-level equation-of-motion coupled-cluster studies of fused porphyrin systems

    Energy Technology Data Exchange (ETDEWEB)

    Kowalski, Karol [Pacific Northwest National Laboratory (PNNL); Olson, Ryan M [Cray, Inc.; Krishnamoorthy, Sriram [Pacific Northwest National Laboratory (PNNL); Tipparaju, Vinod [ORNL; Apra, Edoardo [ORNL

    2011-01-01

    The unusual photophysical properties of the {pi}-conjugated chromophores make them potential building blocks of various molecular devices. In particular, significant narrowing of the HOMO-LUMO gaps can be observed as an effect of functionalization chromophores with polycyclic aromatic hydrocarbons (PAHs). In this paper we present equation-of-motion coupled cluster (EOMCC) calculations for vertical excitation energies of several functionalized forms of porphyrins. The results for free-base porphyrin (FBP) clearly demonstrate significant differences between functionalization of FBP with one- (anthracene) and two-dimensional (coronene) structures. We also compare the EOMCC results with the experimentally available results for anthracene fused zinc-porphyrin. The impact of various types of correlation effects is illustrated on several benchmark models, where the comparison with the experiment is possible. In particular, we demonstrate that for all excited states considered in this paper, all of them being dominated by single excitations, the inclusion of triply excited configurations is crucial for attaining qualitative agreement with experiment. We also demonstrate the parallel performance of the most computationally intensive part of the completely renormalized EOMCCSD(T) approach (CR-EOMCCSD(T)) across 120000 cores.

  15. Development and characterization of glutathione-conjugated albumin nanoparticles for improved brain delivery of hydrophilic fluorescent marker.

    Science.gov (United States)

    Patel, Prerak J; Acharya, Niyati S; Acharya, Sanjeev R

    2013-01-01

    The glutathione-conjugated bovine serum albumin (BSA) nanoparticles were constructed in the present exploration as a novel biodegradable carrier for brain-specific drug delivery with evaluation of its in vitro and in vivo delivery properties. BSA nanocarriers were activated and conjugated to the distal amine functions of the glutathione via carbodiimide chemistry using EDAC as a mediator. These nanoparticles were characterized for particle shape, average size, SPAN value, drug entrapment and in vitro drug release. Further, presence of glutathione on the surface of BSA nanoparticles was confirmed by Ellman's assay, which has suggested that approximately 750 units of glutathione were conjugated per BSA nanoparticle. To evaluate the brain delivery properties of the glutathione-conjugated BSA nanoparticles fluorescein sodium was used as a model hydrophilic compound. Permeability and neuronal uptake properties of developed formulations were evaluated against the MDCK-MDR1 endothelial and neuro-glial cells, respectively. The permeability of glutathione-conjugated BSA nanoparticles across the monolayer of MDCK-MDR1 endothelial tight junction was shown significantly higher than that of unconjugated nanoparticles and fluorescein sodium solution. Similarly, glutathione-conjugated nanoparticles exhibited considerably higher uptake by neuro-glial cells which was inferred by high fluorescence intensity under microscope in comparison to unconjugated nanoparticles and fluorescein sodium solution. Following an intravenous administration, nearly three folds higher fluorescein sodium was carried to the rat brain by glutathione-conjugated nanoparticles as compared to unconjugated nanoparticles. The significant in vitro and in vivo results suggest that glutathione-conjugated BSA nanoparticles is a promising brain drug delivery system with low toxicity.

  16. Direct Cytoplasmic Delivery and Nuclear Targeting Delivery of HPMA-MT Conjugates in a Microtubules Dependent Fashion.

    Science.gov (United States)

    Zhong, Jiaju; Zhu, Xi; Luo, Kui; Li, Lian; Tang, Manlin; Liu, Yanxi; Zhou, Zhou; Huang, Yuan

    2016-09-06

    As the hearts of tumor cells, the nucleus is the ultimate target of many chemotherapeutic agents and genes. However, nuclear drug delivery is always hampered by multiple intracellular obstacles, such as low efficiency of lysosome escape and insufficient nuclear trafficking. Herein, an N-(2-hydroxypropyl) methacrylamide (HPMA) polymer-based drug delivery system was designed, which could achieve direct cytoplasmic delivery by a nonendocytic pathway and transport into the nucleus in a microtubules dependent fashion. A special targeting peptide (MT), derived from an endogenic parathyroid hormone-related protein, was conjugated to the polymer backbone, which could accumulate into the nucleus a by microtubule-mediated pathway. The in vitro studies found that low temperature and NaN3 could not influence the cell internalization of the conjugates. Besides, no obvious overlay of the conjugates with lysosome demonstrated that the polymer conjugates could enter the tumor cell cytoplasm by a nonendocytic pathway, thus avoiding the drug degradation in the lysosome. Furthermore, after suppression of the microtubule dynamics with microtubule stabilizing docetaxel (DTX) and destabilizing nocodazole (Noc), the nuclear accumulation of polymeric conjugates was significantly inhibited. Living cells fluorescence recovery after photobleaching study found that the nuclear import rate of conjugates was 2-fold faster compared with the DTX and Noc treated groups. These results demonstrated that the conjugates transported into the nucleus in a microtubules dependent way. Therefore, in addition to direct cytoplasmic delivery, our peptide conjugated polymeric platform could simultaneously mediate nuclear drug accumulation, which may open a new path for further intracellular genes/peptides delivery.

  17. Minimizing inner product data dependencies in conjugate gradient iteration

    Science.gov (United States)

    Vanrosendale, J.

    1983-01-01

    The amount of concurrency available in conjugate gradient iteration is limited by the summations required in the inner product computations. The inner product of two vectors of length N requires time c log(N), if N or more processors are available. This paper describes an algebraic restructuring of the conjugate gradient algorithm which minimizes data dependencies due to inner product calculations. After an initial start up, the new algorithm can perform a conjugate gradient iteration in time c*log(log(N)).

  18. A complete implementation of the conjugate gradient algorithm on a reconfigurable supercomputer

    International Nuclear Information System (INIS)

    Dubois, David H.; Dubois, Andrew J.; Connor, Carolyn M.; Boorman, Thomas M.; Poole, Stephen W.

    2008-01-01

    The conjugate gradient is a prominent iterative method for solving systems of sparse linear equations. Large-scale scientific applications often utilize a conjugate gradient solver at their computational core. In this paper we present a field programmable gate array (FPGA) based implementation of a double precision, non-preconditioned, conjugate gradient solver for fmite-element or finite-difference methods. OUf work utilizes the SRC Computers, Inc. MAPStation hardware platform along with the 'Carte' software programming environment to ease the programming workload when working with the hybrid (CPUIFPGA) environment. The implementation is designed to handle large sparse matrices of up to order N x N where N <= 116,394, with up to 7 non-zero, 64-bit elements per sparse row. This implementation utilizes an optimized sparse matrix-vector multiply operation which is critical for obtaining high performance. Direct parallel implementations of loop unrolling and loop fusion are utilized to extract performance from the various vector/matrix operations. Rather than utilize the FPGA devices as function off-load accelerators, our implementation uses the FPGAs to implement the core conjugate gradient algorithm. Measured run-time performance data is presented comparing the FPGA implementation to a software-only version showing that the FPGA can outperform processors running up to 30x the clock rate. In conclusion we take a look at the new SRC-7 system and estimate the performance of this algorithm on that architecture.

  19. Methotrexate and epirubicin conjugates as potential antitumor drugs

    Directory of Open Access Journals (Sweden)

    Szymon Wojciech Kmiecik

    2017-07-01

    Full Text Available Introduction: The use of hybrid molecules has become one of the most significant approaches in new cytotoxic drug design. This study describes synthesis and characterization of conjugates consisting of two well-known and characterized chemotherapeutic agents: methotrexate (MTX and epirubicin (EPR. The synthesized conjugates combine two significant anticancer strategies: combinatory therapy and targeted therapy. These two drugs were chosen because they have different mechanisms of action, which can increase the anticancer effect of the obtained conjugates. MTX, which is a folic acid analog, has high cytotoxic properties and can serve as a targeting moiety that can reach folate receptors (FRs overexpresing tumor cells. Combination of nonselective drugs such as EPR with MTX can increase the selectivity of the obtained conjugates, while maintaining the high cytotoxic properties.Materials and methods: Conjugates were purified by RP-HPLC and the structure was investigated by MS and MS/MS methods. The effect of the conjugates on proliferation of LoVo, LoVo/Dx, MCF-7 and MV-4-11 human cancer cell lines was determined by SRB or MTT assay.Results: The conjugation reaction results in the formation of monosubstituted (α, γ and disubstituted MTX derivatives. In vitro proliferation data demonstrate that the conjugates synthesized in our study show lower cytotoxic properties than both chemotherapeutics used alone.Discussion: Epirubicin cytotoxicity was not observed in obtained conjugates. Effective drugs release after internalization needs further investigation.

  20. Poly(2-oxazoline)-Antibiotic Conjugates with Penicillins.

    Science.gov (United States)

    Schmidt, Martin; Bast, Livia K; Lanfer, Franziska; Richter, Lena; Hennes, Elisabeth; Seymen, Rana; Krumm, Christian; Tiller, Joerg C

    2017-09-20

    The conjugation of antibiotics with polymers is rarely done, but it might be a promising alternative to low-molecular-weight derivatization. The two penicillins penicillin G (PenG) and penicillin V (PenV) were attached to the end groups of different water-soluble poly(2-oxazoline)s (POx) via their carboxylic acid function. This ester group was shown to be more stable against hydrolysis than the β-lactam ring of the penicillins. The conjugates are still antimicrobially active and up to 20 times more stable against penicillinase catalyzed hydrolysis. The antibiotic activity of the conjugates against Staphylococcus aureus in the presence of penicillinase is up to 350 times higher compared with the free antibiotics. Conjugates with a second antimicrobial function, a dodecyltrimethylammonium group (DDA-X), at the starting end of the PenG and PenV POx conjugates are more antimicrobially active than the conjugates without DDA-X and show high activity in the presence of penicillinase. For example, the conjugates DDA-X-PEtOx-PenG and DDA-X-PEtOx-PenV are 200 to 350 times more active against S. aureus in the presence of penicillinase and almost as effective as the penicillinase stable cloxacollin (Clox) under these conditions. These conjugates show even greater activity compared to cloxacollin without this enzyme present. Further, both conjugates kill Escherichia coli more effectively than PenG and Clox.

  1. Sources and Bioactive Properties of Conjugated Dietary Fatty Acids.

    Science.gov (United States)

    Hennessy, Alan A; Ross, Paul R; Fitzgerald, Gerald F; Stanton, Catherine

    2016-04-01

    The group of conjugated fatty acids known as conjugated linoleic acid (CLA) isomers have been extensively studied with regard to their bioactive potential in treating some of the most prominent human health malignancies. However, CLA isomers are not the only group of potentially bioactive conjugated fatty acids currently undergoing study. In this regard, isomers of conjugated α-linolenic acid, conjugated nonadecadienoic acid and conjugated eicosapentaenoic acid, to name but a few, have undergone experimental assessment. These studies have indicated many of these conjugated fatty acid isomers commonly possess anti-carcinogenic, anti-adipogenic, anti-inflammatory and immune modulating properties, a number of which will be discussed in this review. The mechanisms through which these bioactivities are mediated have not yet been fully elucidated. However, existing evidence indicates that these fatty acids may play a role in modulating the expression of several oncogenes, cell cycle regulators, and genes associated with energy metabolism. Despite such bioactive potential, interest in these conjugated fatty acids has remained low relative to the CLA isomers. This may be partly attributed to the relatively recent emergence of these fatty acids as bioactives, but also due to a lack of awareness regarding sources from which they can be produced. In this review, we will also highlight the common sources of these conjugated fatty acids, including plants, algae, microbes and chemosynthesis.

  2. Complex conjugate poles and parton distributions

    International Nuclear Information System (INIS)

    Tiburzi, B.C.; Detmold, W.; Miller, G.A.

    2003-01-01

    We calculate parton and generalized parton distributions in Minkowski space using a scalar propagator with a pair of complex conjugate poles. Correct spectral and support properties are obtained only after careful analytic continuation from Euclidean space. Alternately the quark distribution function can be calculated from modified cutting rules, which put the intermediate state on its complex mass shells. Distribution functions agree with those resulting from the model's Euclidean space double distribution which we calculate via nondiagonal matrix elements of twist-two operators. Thus one can use a wide class of analytic parametrizations of the quark propagator to connect Euclidean space Green functions to light-cone dominated amplitudes

  3. PET regularization by envelope guided conjugate gradients

    International Nuclear Information System (INIS)

    Kaufman, L.; Neumaier, A.

    1996-01-01

    The authors propose a new way to iteratively solve large scale ill-posed problems and in particular the image reconstruction problem in positron emission tomography by exploiting the relation between Tikhonov regularization and multiobjective optimization to obtain iteratively approximations to the Tikhonov L-curve and its corner. Monitoring the change of the approximate L-curves allows us to adjust the regularization parameter adaptively during a preconditioned conjugate gradient iteration, so that the desired solution can be reconstructed with a small number of iterations

  4. The SXT conjugative element and linear prophage N15 encode toxin-antitoxin-stabilizing systems homologous to the tad-ata module of the Paracoccus aminophilus plasmid pAMI2.

    Science.gov (United States)

    Dziewit, Lukasz; Jazurek, Magdalena; Drewniak, Lukasz; Baj, Jadwiga; Bartosik, Dariusz

    2007-03-01

    A group of proteic toxin-antitoxin (TA) cassettes whose representatives are widely distributed among bacterial genomes has been identified. These cassettes occur in chromosomes, plasmids, bacteriophages, and noncomposite transposons, as well as in the SXT conjugative element of Vibrio cholerae. The following four homologous loci were subjected to detailed comparative studies: (i) tad-ata from plasmid pAMI2 of Paracoccus aminophilus (the prototype of this group), (ii) gp49-gp48 from the linear bacteriophage N15 of Escherichia coli, (iii) s045-s044 from SXT, and (iv) Z3230-Z3231 from the genomic island of enterohemorrhagic Escherichia coli O157:H7 strain EDL933. Functional analysis revealed that all but one of these loci (Z3230-Z3231) are able to stabilize heterologous replicons, although the host ranges varied. The TA cassettes analyzed have the following common features: (i) the toxins are encoded by the first gene of each operon; (ii) the antitoxins contain a predicted helix-turn-helix motif of the XRE family; and (iii) the cassettes have two promoters that are different strengths, one which is located upstream of the toxin gene and one which is located upstream of the antitoxin gene. All four toxins tested are functional in E. coli; overexpression of the toxins (in the absence of antitoxin) results in a bacteriostatic effect manifested by elongation of bacterial cells and growth arrest. The toxins have various effects on cell viability, which suggests that they may recognize different intracellular targets. Preliminary data suggest that different cellular proteases are involved in degradation of antitoxins encoded by the loci analyzed.

  5. Charge transport in conjugated polymers: a multiscale picture

    Science.gov (United States)

    Ruehle, Victor; Kirkpatrick, James; Kremer, Kurt; Andrienko, Denis

    2009-03-01

    A framework to study charge transport in conjugated polymers using realistic morphologies is developed. First, the atomistic force field is refined using first-principles calculations. Systematic coarse graining is then performed to extend simulation times and system sizes accessible to molecular dynamics simulations. Material morphologies are generated using the coarse grained and atomistic models. Finally, the charge mobility is obtained using temperature activated hopping picture for charge transport [1]. The framework is tested on neutral and oxidized polypyrrole with different structural ordering [2]. [4pt] [1] J. Kirkpatrick, V. Marcon, J. Nelson, K. Kremer, D. Andrienko, Phys. Rev. Lett. 98, 227402 (2007)[0pt] [2] V. Ruehle, J. Kirkpatrick, K. Kremer, D. Andrienko, Phys. Stat. Solidi B, 245, 844 (2008)

  6. Oxidative modifications of conjugated and unconjugated linoleic acid during heating.

    Science.gov (United States)

    Giua, L; Blasi, F; Simonetti, M S; Cossignani, L

    2013-10-15

    The oxidative stability of conjugated linoleic (CLA) and linoleic (LA) acids in different chemical forms (free acids, methyl esters and homogeneous triacylglycerols) was compared. All model systems were heated at 180°C for different times (15, 30, 45 and 60min). The primary oxidation products were evaluated by spectrophometric analysis, while the volatile compounds were determined by solid phase micro-extraction (SPME), coupled with gas chromatography-mass spectrometry (HRGC-MS). The isomer profile modifications were investigated by silver-ion high performance liquid chromatography (Ag(+)-HPLC) equipped with an UV detector. Generally, peroxide values decreased during the heating time. Among the volatiles, saturated aldehydes were the most represented compounds. Isomerization of cis,trans and trans,cis CLA to trans,trans isomers was observed mainly for the methyl form of CLA. The three different chemical forms of LA never showed isomerization phenomena. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. A conjugate thermo-electric model for a composite medium.

    Directory of Open Access Journals (Sweden)

    Oscar Chávez

    Full Text Available Electrical transmission signals have been used for decades to characterize the internal structure of composite materials. We theoretically analyze the transmission of an electrical signal through a composite material which consists of two phases with different chemical compositions. We assume that the temperature of the biphasic system increases as a result of Joule heating and its electrical resistivity varies linearly with temperature; this last consideration leads to simultaneously study the electrical and thermal effects. We propose a nonlinear conjugate thermo-electric model, which is solved numerically to obtain the current density and temperature profiles for each phase. We study the effect of frequency, resistivities and thermal conductivities on the current density and temperature. We validate the prediction of the model with comparisons with experimental data obtained from rock characterization tests.

  8. Preparation and characterization of a hetero functional system of gold nanoparticles labeled with 99mTc and conjugated to the sequence Arg-Gly-Asp for detection in vivo of angio genesis and evaluation of their toxicity in Hyalella aztec

    International Nuclear Information System (INIS)

    Morales A, E.

    2012-01-01

    Integrin s play critical roles in many physiological processes including angio genesis and also contribute to pathological events such as tumor invasion and metastasis. The α v β 3 integrin is expressed in normal endothelial cells but it is over-expressed in the tumor neo vasculature. Peptides based on the Arginine-Glycine-Aspartic acid (RGD) sequence have been reported as molecules with high affinity and selectivity for the α v β 3 integrin. Recent studies have demonstrated that conjugating peptides to gold nanoparticles (AuNP) produces biocompatible and stable multifunctional systems with target-specific molecular recognition due to multivalent effects produced by multiple simultaneous interactions between peptides and their receptors. The first aim of this research was to prepare a m ultimeric system of 99m Tc labeled gold particles conjugated to c[RGDfK(C)] and to evaluate its biological behavior as a potential radiopharmaceutical for molecular imaging of α v β 3 tumor expression. Hidrazinonicotinamide-G GC (HYNIC-G GC) and C[RGDfK(C)] peptides were synthesized and conjugated to AuNP (20 nm) by means of spontaneous reaction of the thiol groups of cysteine. The nano conjugate was characterized by transmission electron microscopy, Fourier transform-infrared, Ultraviolet-vis, X-ray photoelectron spectroscopy and Raman spectroscopy. To obtain 99m Tc-HYNIC-G GC-AuNP-c[RGDfK(C)], the 99m Tc-HYNIC-G GC radio peptide was first prepared and added to the AuNP solution followed by c[RGDfK(C)]. Radiochemical purity (Rp) was determined by size-exclusion HPLC and I TLC-Sg analyses. In vitro binding studies were carried out in α v β 3 receptor-positive C6 glioma cancer cells. Biodistribution studies were accomplished in athymic mice with C6-induced tumors with blocked and non blocked receptors, and images were obtained using a micro-SPECT/CT. Transmission electron microscopy and spectroscopy techniques demonstrated that AuNP were functionalized with peptides. Rp was

  9. Applications of phase conjugate mirror to Thomson scattering diagnostics (invited)

    International Nuclear Information System (INIS)

    Hatae, T.; Naito, O.; Nakatsuka, M.; Yoshida, H.

    2006-01-01

    A high performance phase conjugate mirror based on stimulated Brillouin scattering (SBS-PCM) has been applied to the Thomson scattering system in the JT-60U tokamak for the first time in order to improve the measurement performance. A SBS-PCM realized a high reflectivity of 95% at a high input power of 145 W (2.9 J, 50 Hz). Using the SBS-PCM, two methods have been developed to increase the intensity of scattered light. For the first method, we have developed a new optical design to provide a double-pass scattering method with the SBS-PCM. A laser beam passing through the plasma is reflected by the SBS-PCM. The reflected beam passes the plasma again along the same path by means of the phase conjugation of the optically nonlinear stimulated Brillouin scattering process. The double-pass Thomson scattering method using the SBS-PCM has demonstrated an increase of the scattered light by a factor of 1.6 compared with the single-pass scattering method in JT-60U. A multipass Thomson scattering method in which the laser beam can be confined between a couple of SBS-PCMs is also proposed. It is estimated that the multipass scattering method generates the scattered light more than several times as large as that of the single-pass scattering method. For the second method, a high-average-power yttrium aluminum garnet (Nd:YAG) laser system has been developed using the SBS-PCM. The SBS-PCM effectively compensated thermal degradation at two amplifier lines, and the average power was increased by a factor of >8 from 45 W (1.5 J, 30 Hz) to 373 W (7.46 J, 50 Hz). A Nd:YAG laser (5 J, 100 Hz) for the edge Thomson scattering in International Thermonuclear Experimental Reactor (ITER) has been designed based on the result

  10. In Vitro Evaluation of Third Generation PAMAM Dendrimer Conjugates

    Directory of Open Access Journals (Sweden)

    Mohammad Najlah

    2017-10-01

    Full Text Available The present study compares the use of high generation G3 and low generation G0 Polyamidoamine (PAMAM dendrimers as drug carriers of naproxen (NAP, a poorly water soluble drug. Naproxen was conjugated to G3 in different ratios and to G0 in a 1:1 ratio via a diethylene glycol linker. A lauroyl chain (L, a lipophilic permeability enhancer, was attached to G3 and G0 prodrugs. The G3 and G0 conjugates were more hydrophilic than naproxen as evaluated by the measurement of partitioning between 1-octanol and a phosphate buffer at pH 7.4 and pH 1.2. The unmodified surface PAMAM-NAP conjugates showed significant solubility enhancements of NAP at pH 1.2; however, with the number of NAP conjugated to G3, this was limited to 10 molecules. The lactate dehydrogenase (LDH assay indicated that the G3 dendrimer conjugates had a concentration dependent toxicity towards Caco-2 cells. Attaching naproxen to the surface of the dendrimer increased the IC50 of the resulting prodrugs towards Caco-2 cells. The lauroyl G3 conjugates showed the highest toxicity amongst the PAMAM dendrimer conjugates investigated and were significantly more toxic than the lauroyl-G0-naproxen conjugates. The permeability of naproxen across monolayers of Caco-2 cells was significantly increased by its conjugation to either G3 or G0 PAMAM dendrimers. Lauroyl-G0 conjugates displayed considerably lower cytotoxicity than G3 conjugates and may be preferable for use as a drug carrier for low soluble drugs such as naproxen.

  11. Long-distance transmission over standard fiber by use of mid-way phase conjugation

    DEFF Research Database (Denmark)

    Zhang, Xiupu; Ebskamp, Frank; Jørgensen, Bo Foged

    1995-01-01

    In this letter, we predict transmission over more than 6000 km using standard fiber with the application of mid-way phase-conjugation in a 1.55-μm, 10-Gb/s IM/DD system with in-line amplifiers for the power penalty at BER=10-9, which is less than 6 dB; the system must operate with an average powe...... into the fiber within the range of -5 to 5 dBm...

  12. Tetraspanin CD63 Bridges Autophagic and Endosomal Processes To Regulate Exosomal Secretion and Intracellular Signaling of Epstein-Barr Virus LMP1

    Science.gov (United States)

    Hurwitz, Stephanie N; Cheerathodi, Mujeeb R; Nkosi, Dingani; York, Sara B; Meckes, David G

    2018-03-01

    The tetraspanin protein CD63 has been recently described as a key factor in extracellular vesicle (EV) production and endosomal cargo sorting. In the context of Epstein-Barr virus (EBV) infection, CD63 is required for the efficient packaging of the major viral oncoprotein latent membrane protein 1 (LMP1) into exosomes and other EV populations and acts as a negative regulator of LMP1 intracellular signaling. Accumulating evidence has also pointed to intersections of the endosomal and autophagy pathways in maintaining cellular secretory processes and as sites for viral assembly and replication. Indeed, LMP1 can activate the mammalian target of rapamycin (mTOR) pathway to suppress host cell autophagy and facilitate cell growth and proliferation. Despite the growing recognition of cross talk between endosomes and autophagosomes and its relevance to viral infection, little is understood about the molecular mechanisms governing endosomal and autophagy convergence. Here, we demonstrate that CD63-dependent vesicle protein secretion directly opposes intracellular signaling activation downstream of LMP1, including mTOR-associated proteins. Conversely, disruption of normal autolysosomal processes increases LMP1 secretion and dampens signal transduction by the viral protein. Increases in mTOR activation following CD63 knockout are coincident with the development of serum-dependent autophagic vacuoles that are acidified in the presence of high LMP1 levels. Altogether, these findings suggest a key role of CD63 in regulating the interactions between endosomal and autophagy processes and limiting cellular signaling activity in both noninfected and virally infected cells. IMPORTANCE The close connection between extracellular vesicles and viruses is becoming rapidly and more widely appreciated. EBV, a human gamma herpesvirus that contributes to the progression of a multitude of lymphomas and carcinomas in immunocompromised or genetically susceptible populations, packages its major

  13. Attenuation of Aβ25–35-induced parallel autophagic and apoptotic cell death by gypenoside XVII through the estrogen receptor-dependent activation of Nrf2/ARE pathways

    International Nuclear Information System (INIS)

    Meng, Xiangbao; Wang, Min; Sun, Guibo; Ye, Jingxue; Zhou, Yanhui; Dong, Xi; Wang, Tingting; Lu, Shan; Sun, Xiaobo

    2014-01-01

    Amyloid-beta (Aβ) has a pivotal function in the pathogenesis of Alzheimer's disease. To investigate Aβ neurotoxicity, we used an in vitro model that involves Aβ 25–35 -induced cell death in the nerve growth factor-induced differentiation of PC12 cells. Aβ 25–35 (20 μM) treatment for 24 h caused apoptotic cell death, as evidenced by significant cell viability reduction, LDH release, phosphatidylserine externalization, mitochondrial membrane potential disruption, cytochrome c release, caspase-3 activation, PARP cleavage, and DNA fragmentation in PC12 cells. Aβ 25–35 treatment led to autophagic cell death, as evidenced by augmented GFP-LC3 puncta, conversion of LC3-I to LC3-II, and increased LC3-II/LC3-I ratio. Aβ 25–35 treatment induced oxidative stress, as evidenced by intracellular ROS accumulation and increased production of mitochondrial superoxide, malondialdehyde, protein carbonyl, and 8-OHdG. Phytoestrogens have been proved to be protective against Aβ-induced neurotoxicity and regarded as relatively safe targets for AD drug development. Gypenoside XVII (GP-17) is a novel phytoestrogen isolated from Gynostemma pentaphyllum or Panax notoginseng. Pretreatment with GP-17 (10 μM) for 12 h increased estrogen response element reporter activity, activated PI3K/Akt pathways, inhibited GSK-3β, induced Nrf2 nuclear translocation, augmented antioxidant responsive element enhancer activity, upregulated heme oxygenase 1 (HO-1) expression and activity, and provided protective effects against Aβ 25–35 -induced neurotoxicity, including oxidative stress, apoptosis, and autophagic cell death. In conclusion, GP-17 conferred protection against Aβ 25–35 -induced neurotoxicity through estrogen receptor-dependent activation of PI3K/Akt pathways, inactivation of GSK-3β and activation of Nrf2/ARE/HO-1 pathways. This finding might provide novel insights into understanding the mechanism for neuroprotective effects of phytoestrogens or gypenosides

  14. Paclitaxel and the dietary flavonoid fisetin: a synergistic combination that induces mitotic catastrophe and autophagic cell death in A549 non-small cell lung cancer cells.

    Science.gov (United States)

    Klimaszewska-Wisniewska, Anna; Halas-Wisniewska, Marta; Tadrowski, Tadeusz; Gagat, Maciej; Grzanka, Dariusz; Grzanka, Alina

    2016-01-01

    The use of the dietary polyphenols as chemosensitizing agents to enhance the efficacy of conventional cytostatic drugs has recently gained the attention of scientists and clinicians as a plausible approach for overcoming the limitations of chemotherapy (e.g. drug resistance and cytotoxicity). The aim of this study was to investigate whether a naturally occurring diet-based flavonoid, fisetin, at physiologically attainable concentrations, could act synergistically with clinically achievable doses of paclitaxel to produce growth inhibitory and/or pro-death effects on A549 non-small cell lung cancer cells, and if it does, what mechanisms might be involved. The drug-drug interactions were analyzed based on the combination index method of Chou and Talalay and the data from MTT assays. To provide some insights into the mechanism underlying the synergistic action of fisetin and paclitaxel, selected morphological, biochemical and molecular parameters were examined, including the morphology of cell nuclei and mitotic spindles, the pattern of LC3-II immunostaining, the formation of autophagic vacuoles at the electron and fluorescence microscopic level, the disruption of cell membrane asymmetry/integrity, cell cycle progression and the expression level of LC3-II, Bax, Bcl-2 and caspase-3 mRNA. Here, we reported the first experimental evidence for the existence of synergism between fisetin and paclitaxel in the in vitro model of non-small cell lung cancer. This synergism was, at least partially, ascribed to the induction of mitotic catastrophe. The switch from the cytoprotective autophagy to the autophagic cell death was also implicated in the mechanism of the synergistic action of fisetin and paclitaxel in the A549 cells. In addition, we revealed that the synergism between fisetin and paclitaxel was cell line-specific as well as that fisetin synergizes with arsenic trioxide, but not with mitoxantrone and methotrexate in the A549 cells. Our results provide rationale for

  15. π-Clamp-mediated cysteine conjugation

    Science.gov (United States)

    Zhang, Chi; Welborn, Matthew; Zhu, Tianyu; Yang, Nicole J.; Santos, Michael S.; van Voorhis, Troy; Pentelute, Bradley L.

    2016-02-01

    Site-selective functionalization of complex molecules is one of the most significant challenges in chemistry. Typically, protecting groups or catalysts must be used to enable the selective modification of one site among many that are similarly reactive, and general strategies that selectively tune the local chemical environment around a target site are rare. Here, we show a four-amino-acid sequence (Phe-Cys-Pro-Phe), which we call the ‘π-clamp’, that tunes the reactivity of its cysteine thiol for site-selective conjugation with perfluoroaromatic reagents. We use the π-clamp to selectively modify one cysteine site in proteins containing multiple endogenous cysteine residues. These examples include antibodies and cysteine-based enzymes that would be difficult to modify selectively using standard cysteine-based methods. Antibodies modified using the π-clamp retained binding affinity to their targets, enabling the synthesis of site-specific antibody-drug conjugates for selective killing of HER2-positive breast cancer cells. The π-clamp is an unexpected approach to mediate site-selective chemistry and provides new avenues to modify biomolecules for research and therapeutics.

  16. The multigrid preconditioned conjugate gradient method

    Science.gov (United States)

    Tatebe, Osamu

    1993-01-01

    A multigrid preconditioned conjugate gradient method (MGCG method), which uses the multigrid method as a preconditioner of the PCG method, is proposed. The multigrid method has inherent high parallelism and improves convergence of long wavelength components, which is important in iterative methods. By using this method as a preconditioner of the PCG method, an efficient method with high parallelism and fast convergence is obtained. First, it is considered a necessary condition of the multigrid preconditioner in order to satisfy requirements of a preconditioner of the PCG method. Next numerical experiments show a behavior of the MGCG method and that the MGCG method is superior to both the ICCG method and the multigrid method in point of fast convergence and high parallelism. This fast convergence is understood in terms of the eigenvalue analysis of the preconditioned matrix. From this observation of the multigrid preconditioner, it is realized that the MGCG method converges in very few iterations and the multigrid preconditioner is a desirable preconditioner of the conjugate gradient method.

  17. Thiolated polymers--thiomers: development and in vitro evaluation of chitosan-thioglycolic acid conjugates.

    Science.gov (United States)

    Kast, C E; Bernkop-Schnürch, A

    2001-09-01

    The aim of this study was to improve mucoadhesive properties of chitosan by the covalent attachment of thiol moieties to this cationic polymer. Mediated by a carbodiimide, thioglycolic acid (TGA) was covalently attached to chitosan. This was achieved by the formation of amide bonds between the primary amino groups of the polymer and the carboxylic acid group of TGA. Dependent on the pH-value and the weight ratio of polymer to TGA during the coupling reaction the resulting thiolated polymers, the so-called thiomers, displayed 6.58, 9.88, 27.44, and 38.23 micromole thiol groups per gram polymer. Tensile studies carried out with these chitosan-TGA conjugates on freshly excised porcine intestinal mucosa demonstrated a 6.3-, 8.6-, 8.9-, and 10.3-fold increase in the total work of adhesion (TWA) compared to the unmodified polymer, respectively. In contrast, the combination of chitosan and free unconjugated TGA showed almost no mucoadhesion. These data were in good correlation with further results obtained by another mucoadhesion test demonstrating a prolonged residence time of thiolated chitosan on porcine mucosa. The swelling behavior of all conjugates was thereby exactly in the same range as for an unmodified polymer pretreated in the same way. Furthermore, it could be shown that chitosan-TGA conjugates are still biodegradable by the glycosidase lysozyme. According to these results. chitosan-TGA conjugates represent a promising tool for the development of mucoadhesive drug delivery systems.

  18. Mitochondrial associated ubiquitin fold modifier-1 mediated protein conjugation in Leishmania donovani.

    Directory of Open Access Journals (Sweden)

    Sreenivas Gannavaram

    2011-01-01

    Full Text Available In this report, we demonstrate the existence of the ubiquitin fold modifier-1 (Ufm1 and its conjugation pathway in trypanosomatid parasite Leishmania donovani. LdUfm1 is activated by E1-like enzyme LdUba5. LdUfc1 (E2 specifically interacted with LdUfm1 and LdUba5 to conjugate LdUfm1 to proteinaceous targets. Mass spectrometry analysis revealed that LdUfm1 is conjugated to Leishmania protein targets that are associated with mitochondria. Immunofluorescence experiments showed that Leishmania Ufm1, Uba5 and Ufc1 are associated with the mitochondria. The demonstration that all the components of this system as well as the substrates are associated with mitochondrion suggests it may have physiological roles not yet described in any other organism. Overexpression of a non-conjugatable form of LdUfm1 and an active site mutant of LdUba5 resulted in reduced survival of Leishmania in the macrophage. Since mitochondrial activities are developmentally regulated in the life cycle of trypanosomatids, Ufm1 mediated modifications of mitochondrial proteins may be important in such regulation. Thus, Ufm1 conjugation pathway in Leishmania could be explored as a potential drug target in the control of Leishmaniasis.

  19. Solving Optimal Control Problem of Monodomain Model Using Hybrid Conjugate Gradient Methods

    Directory of Open Access Journals (Sweden)

    Kin Wei Ng

    2012-01-01

    Full Text Available We present the numerical solutions for the PDE-constrained optimization problem arising in cardiac electrophysiology, that is, the optimal control problem of monodomain model. The optimal control problem of monodomain model is a nonlinear optimization problem that is constrained by the monodomain model. The monodomain model consists of a parabolic partial differential equation coupled to a system of nonlinear ordinary differential equations, which has been widely used for simulating cardiac electrical activity. Our control objective is to dampen the excitation wavefront using optimal applied extracellular current. Two hybrid conjugate gradient methods are employed for computing the optimal applied extracellular current, namely, the Hestenes-Stiefel-Dai-Yuan (HS-DY method and the Liu-Storey-Conjugate-Descent (LS-CD method. Our experiment results show that the excitation wavefronts are successfully dampened out when these methods are used. Our experiment results also show that the hybrid conjugate gradient methods are superior to the classical conjugate gradient methods when Armijo line search is used.

  20. Thiolated polymers: synthesis and in vitro evaluation of polymer-cysteamine conjugates.

    Science.gov (United States)

    Bernkop-Schnürch, A; Clausen, A E; Hnatyszyn, M

    2001-09-11

    The purpose of the present study was to synthesize and characterize novel thiolated polymers. Mediated by a carbodiimide cysteamine was covalently linked to sodium carboxymethylcellulose (CMC) and polycarbophil (PCP). The resulting CMC-cysteamine conjugates displayed 77.9+/-6.7 and 365.1+/-8.7 micromol thiol groups per gram of polymer, whereas the PCP-cysteamine conjugates showed 26.3+/-1.9 and 122.7+/-3.8 micromol thiol groups per gram of polymer (mean+/-S.D.; n=3). In aqueous solutions above pH 5.0 both modified polymers were capable of forming inter- and/or intra-molecular disulfide bonds. The reaction velocity of this oxidation process was accelerated with a decrease in the proton concentration. The oxidation proceeded more rapidly within thiolated CMC than within thiolated PCP. Permeation studies carried out in Ussing-type chambers with freshly excised intestinal mucosa from guinea pigs utilizing sodium fluorescein as model drug for the paracellular uptake revealed an enhancement ratio (R=P(app) (conjugate)/P(app) (control)) of 1.15 and 1.41 (mean+/-S.D.; n=3) for the higher thiolated CMC-cysteamine (0.5%; m/v) and PCP-cysteamine conjugate (1.0%; m/v), respectively. The decrease in the transepithelial electrical resistance values was in good correlation with the enhancement ratios. Due to a high crosslinking tendency by the formation of disulfide bonds stabilizing drug carrier systems based on thiolated polymers and a permeation enhancing effect, CMC- and PCP-cysteamine conjugates represent promising excipients for the development of novel drug delivery systems.