WorldWideScience

Sample records for resembling dendritic growth

  1. Isothermal Dendritic Growth Experiment - PVA Dendrites

    Science.gov (United States)

    1997-01-01

    The Isothermal Dendritic Growth Experiment (IDGE), flown on three Space Shuttle missions, is yielding new insights into virtually all industrially relevant metal and alloy forming operations. IDGE used transparent organic liquids that form dendrites (treelike structures) similar to those inside metal alloys. Comparing Earth-based and space-based dendrite growth velocity, tip size and shape provides a better understanding of the fundamentals of dentritic growth, including gravity's effects. Shalowgraphic images of pivalic acid (PVA) dendrites forming from the melt show the subtle but distinct effects of gravity-driven heat convection on dentritic growth. In orbit, the dendrite grows as its latent heat is liberated by heat conduction. This yields a blunt dendrite tip. On Earth, heat is carried away by both conduction and gravity-driven convection. This yields a sharper dendrite tip. In addition, under terrestrial conditions, the sidebranches growing in the direction of gravity are augmented as gravity helps carry heat out of the way of the growing sidebranches as opposed to microgravity conditions where no augmentation takes place. IDGE was developed by Rensselaer Polytechnic Institute and NASA/Glenn Research Center. Advanced follow-on experiments are being developed for flight on the International Space Station. Photo Credit: NASA/Glenn Research Center

  2. Dendritic growth forms of borax crystals

    International Nuclear Information System (INIS)

    Takoo, R.K.; Patel, B.R.; Joshi, M.S.

    1983-01-01

    A variety of dendritic forms of borax grown from solutions by the film formation method is given. The changing growth morphology is followed as a function of concentration and temperature. The initial, intermediate and final growth morphologies are described and discussed. Influence of evaporation rate and supersaturation on the mechanism of growth is assessed. It is suggested that under all crystallization conditions, borax crystals have dendritic form in the initial stages of growth. (author)

  3. Human XCR1+ dendritic cells derived in vitro from CD34+ progenitors closely resemble blood dendritic cells, including their adjuvant responsiveness, contrary to monocyte-derived dendritic cells.

    Science.gov (United States)

    Balan, Sreekumar; Ollion, Vincent; Colletti, Nicholas; Chelbi, Rabie; Montanana-Sanchis, Frédéric; Liu, Hong; Vu Manh, Thien-Phong; Sanchez, Cindy; Savoret, Juliette; Perrot, Ivan; Doffin, Anne-Claire; Fossum, Even; Bechlian, Didier; Chabannon, Christian; Bogen, Bjarne; Asselin-Paturel, Carine; Shaw, Michael; Soos, Timothy; Caux, Christophe; Valladeau-Guilemond, Jenny; Dalod, Marc

    2014-08-15

    Human monocyte-derived dendritic cell (MoDC) have been used in the clinic with moderately encouraging results. Mouse XCR1(+) DC excel at cross-presentation, can be targeted in vivo to induce protective immunity, and share characteristics with XCR1(+) human DC. Assessment of the immunoactivation potential of XCR1(+) human DC is hindered by their paucity in vivo and by their lack of a well-defined in vitro counterpart. We report in this study a protocol generating both XCR1(+) and XCR1(-) human DC in CD34(+) progenitor cultures (CD34-DC). Gene expression profiling, phenotypic characterization, and functional studies demonstrated that XCR1(-) CD34-DC are similar to canonical MoDC, whereas XCR1(+) CD34-DC resemble XCR1(+) blood DC (bDC). XCR1(+) DC were strongly activated by polyinosinic-polycytidylic acid but not LPS, and conversely for MoDC. XCR1(+) DC and MoDC expressed strikingly different patterns of molecules involved in inflammation and in cross-talk with NK or T cells. XCR1(+) CD34-DC but not MoDC efficiently cross-presented a cell-associated Ag upon stimulation by polyinosinic-polycytidylic acid or R848, likewise to what was reported for XCR1(+) bDC. Hence, it is feasible to generate high numbers of bona fide XCR1(+) human DC in vitro as a model to decipher the functions of XCR1(+) bDC and as a potential source of XCR1(+) DC for clinical use. Copyright © 2014 by The American Association of Immunologists, Inc.

  4. Dendritic growth model of multilevel marketing

    Science.gov (United States)

    Pang, James Christopher S.; Monterola, Christopher P.

    2017-02-01

    Biologically inspired dendritic network growth is utilized to model the evolving connections of a multilevel marketing (MLM) enterprise. Starting from agents at random spatial locations, a network is formed by minimizing a distance cost function controlled by a parameter, termed the balancing factor bf, that weighs the wiring and the path length costs of connection. The paradigm is compared to an actual MLM membership data and is shown to be successful in statistically capturing the membership distribution, better than the previously reported agent based preferential attachment or analytic branching process models. Moreover, it recovers the known empirical statistics of previously studied MLM, specifically: (i) a membership distribution characterized by the existence of peak levels indicating limited growth, and (ii) an income distribution obeying the 80 - 20 Pareto principle. Extensive types of income distributions from uniform to Pareto to a "winner-take-all" kind are also modeled by varying bf. Finally, the robustness of our dendritic growth paradigm to random agent removals is explored and its implications to MLM income distributions are discussed.

  5. Mathematical foundations of the dendritic growth models.

    Science.gov (United States)

    Villacorta, José A; Castro, Jorge; Negredo, Pilar; Avendaño, Carlos

    2007-11-01

    At present two growth models describe successfully the distribution of size and topological complexity in populations of dendritic trees with considerable accuracy and simplicity, the BE model (Van Pelt et al. in J. Comp. Neurol. 387:325-340, 1997) and the S model (Van Pelt and Verwer in Bull. Math. Biol. 48:197-211, 1986). This paper discusses the mathematical basis of these models and analyzes quantitatively the relationship between the BE model and the S model assumed in the literature by developing a new explicit equation describing the BES model (a dendritic growth model integrating the features of both preceding models; Van Pelt et al. in J. Comp. Neurol. 387:325-340, 1997). In numerous studies it is implicitly presupposed that the S model is conditionally linked to the BE model (Granato and Van Pelt in Brain Res. Dev. Brain Res. 142:223-227, 2003; Uylings and Van Pelt in Network 13:397-414, 2002; Van Pelt, Dityatev and Uylings in J. Comp. Neurol. 387:325-340, 1997; Van Pelt and Schierwagen in Math. Biosci. 188:147-155, 2004; Van Pelt and Uylings in Network. 13:261-281, 2002; Van Pelt, Van Ooyen and Uylings in Modeling Dendritic Geometry and the Development of Nerve Connections, pp 179, 2000). In this paper we prove the non-exactness of this assumption, quantify involved errors and determine the conditions under which the BE and S models can be separately used instead of the BES model, which is more exact but considerably more difficult to apply. This study leads to a novel expression describing the BE model in an analytical closed form, much more efficient than the traditional iterative equation (Van Pelt et al. in J. Comp. Neurol. 387:325-340, 1997) in many neuronal classes. Finally we propose a new algorithm in order to obtain the values of the parameters of the BE model when this growth model is matched to experimental data, and discuss its advantages and improvements over the more commonly used procedures.

  6. Stress-driven lithium dendrite growth mechanism and dendrite mitigation by electroplating on soft substrates

    Science.gov (United States)

    Wang, Xu; Zeng, Wei; Hong, Liang; Xu, Wenwen; Yang, Haokai; Wang, Fan; Duan, Huigao; Tang, Ming; Jiang, Hanqing

    2018-03-01

    Problems related to dendrite growth on lithium-metal anodes such as capacity loss and short circuit present major barriers to next-generation high-energy-density batteries. The development of successful lithium dendrite mitigation strategies is impeded by an incomplete understanding of the Li dendrite growth mechanisms, and in particular, Li-plating-induced internal stress in Li metal and its effect on Li growth morphology are not well addressed. Here, we reveal the enabling role of plating residual stress in dendrite formation through depositing Li on soft substrates and a stress-driven dendrite growth model. We show that dendrite growth is mitigated on such soft substrates through surface-wrinkling-induced stress relaxation in the deposited Li film. We demonstrate that this dendrite mitigation mechanism can be utilized synergistically with other existing approaches in the form of three-dimensional soft scaffolds for Li plating, which achieves higher coulombic efficiency and better capacity retention than that for conventional copper substrates.

  7. Free dendritic growth in viscous melts - Cyclohexanol

    Science.gov (United States)

    Singh, N. B.; Glicksman, M. E.

    1989-01-01

    Experiments were carried out to measure the growth speed, V, and dendritic tip radius, R, of highly purified cyclohexanol. The data show that VR-squared = constant over the entire experimentally observed supercooling range, Delta T is between 0.1 and 1 K. The stability parameter estimated from this result indicates that sigma(asterisk) = 0.027, a value in good agreement with the values of sigma(asterisk) found for the cubic plastic crystals succinonitrile pivalic acid. Cyclohexanol differs from other carefully measured plastic crystals in that the viscosity of its melt at the melting point is about 20 times higher, so gravity-induced convection remains weak even at small supercoolings.

  8. Simulation of dendritic growth of magnesium alloys with fluid flow

    Directory of Open Access Journals (Sweden)

    Meng-wu Wu

    2017-11-01

    Full Text Available Fluid flow has a significant impact on the microstructure evolution of alloys during solidification. Based on the previous work relating simulation of the dendritic growth of magnesium alloys with hcp (hexagonal close-packed structure, an extension was made to the formerly established CA (cellular automaton model with the purpose of studying the effect of fluid flow on the dendritic growth of magnesium alloys. The modified projection method was used to solve the transport equations of flow field. By coupling the flow field with the solute field, simulation results of equiaxed and columnar dendritic growth of magnesium alloys with fluid flow were achieved. The simulated results were quantitatively compared with those without fluid flow. Moreover, a comparison was also made between the present work and previous works conducted by others. It can be concluded that a deep understanding of the dendritic growth of magnesium alloys with fluid flow can be obtained by applying the present numerical model.

  9. Dendritic gold nanowire growth observed in liquid with transmission electron microscopy.

    Science.gov (United States)

    Kraus, Tobias; de Jonge, Niels

    2013-07-02

    The growth of nanoscale gold dendrites was studied in situ in a thin liquid film with transmission electron microscopy (TEM) using a liquid cell with silicon nitride (SiN) windows. Gold nanoparticle seeds were covered by a thin liquid layer containing precursor solution. Dendrite nucleation was induced by the electron beam leading to an initial burst of growth. The growth then settled at tip velocities between 0.1 and 2.0 nm/s for different dendrites. Tip velocities fluctuated as different dendrite geometries grew from the tips. Those dendrites showing granularities in their structure experienced the largest growth speed. Comparison of the observed velocities with diffusion-limited growth rates suggests that dendrite growth in thin films at this scale is limited by diffusion. The described method may find application in research on the mechanisms behind dendrite growth and also to study other types of anisotropic growth of nanomaterials driven by crystal and twin geometries.

  10. Containerless Undercooled Melts: Ordering, Nucleation, and Dendrite Growth

    Science.gov (United States)

    Herlach, Dieter M.; Binder, Sven; Galenko, Peter; Gegner, Jan; Holland-Moritz, Dirk; Klein, Stefan; Kolbe, Matthias; Volkmann, Thomas

    2015-11-01

    Electromagnetic and electrostatic levitation are applied to containerless undercool and solidify metallic melts. A large undercooling range becomes accessible with the extra benefit that the freely suspended drop is accessible directly for in situ observation. The short-range order in undercooled melts is investigated by combining levitation with elastic neutron scattering and X-ray scattering using synchrotron radiation. Muon Spin Rotation ( µSR) experiments show magnetic ordering in deeply undercooled Co80Pd20 alloys. The onset of magnetic ordering stimulates nucleation. Results on nucleation undercooling of zirconium are presented showing the limit of maximum undercoolability set by the onset of homogeneous nucleation. Metastable phase diagrams are determined by applying energy-dispersive X-ray diffraction of Ni-V alloys with varying concentration. Nucleation is followed by crystal growth. Rapid dendrite growth velocity is measured on levitation-processed samples as a function of undercooling ∆ T by using high-speed video camera technique. Solute trapping in dilute solid solutions and disorder trapping in intermetallic compounds are experimentally verified. Measurements of glass-forming Cu-Zr alloy show a maximum in the V(∆ T) relation that is indicative for diffusion-controlled growth. The influence of convection on dendrite growth of Al50Ni50 is shown by comparative measurements of dendrite growth velocity on Earth and in reduced gravity. Eventually, faceting of a rough interface by convection is presented as observed on Ni2B alloys.

  11. Analyzing dendritic growth in a population of immature neurons in the adult dentate gyrus using laminar quantification of disjointed dendrites

    Directory of Open Access Journals (Sweden)

    Shira eRosenzweig

    2011-03-01

    Full Text Available In the dentate gyrus of the hippocampus, new granule neurons are continuously produced throughout adult life. A prerequisite for the successful synaptic integration of these neurons is the sprouting and extension of dendrites into the molecular layer of the dentate gyrus. Thus, studies aimed at investigating the developmental stages of adult neurogenesis often use dendritic growth as an important indicator of neuronal health and maturity. Based on the known topography of the dentate gyrus, characterized by distinct laminar arrangement of granule neurons and their extensions, we have developed a new method for analysis of dendritic growth in immature adult-born granule neurons. The method is comprised of laminar quantification of cell bodies, primary, secondary and tertiary dendrites separately and independently from each other. In contrast to most existing methods, laminar quantification of dendrites does not require the use of exogenous markers and does not involve arbitrary selection of individual neurons. The new method relies on immonuhistochemical detection of endogenous markers such as doublecortin to perform a comprehensive analysis of a sub-population of immature neurons. Disjointed, orphan dendrites that often appear in the thin histological sections are taken into account. Using several experimental groups of rats and mice, we demonstrate here the suitable techniques for quantifying neurons and dendrites, and explain how the ratios between the quantified values can be used in a comparative analysis to indicate variations in dendritic growth and complexity.

  12. Characteristics of the Dendrite Growth in the Electrochemical Alane Production Process

    Directory of Open Access Journals (Sweden)

    Park Hyun-Kyu

    2016-01-01

    Full Text Available The electrochemical alane production process was proposed for a feasible production of alane. The operation of process was difficult because of short circuit by a dendrite growth in the reactor. Therefore, characteristics of the dendrite growth in the process were investigated. We conducted the electrochemical alane production process using Teflon block for inhibition of the dendrite growth. The obtained dendrite was characterized by XRD, SEM and ICP-AES. It was concluded that the dendrite growth was attributed to a melting and agglomeration of Al fine particles existed in the solution.

  13. Dendrite Growth Kinetics in Undercooled Melts of Intermetallic Compounds

    Directory of Open Access Journals (Sweden)

    Dieter M. Herlach

    2015-09-01

    Full Text Available Solidification needs an undercooling to drive the solidification front. If large undercoolings are achieved, metastable solid materials are solidified from the undercooled melt. Containerless processing provides the conditions to achieve large undercoolings since heterogeneous nucleation on container walls is completely avoided. In the present contribution both electromagnetic and electrostatic levitation are applied. The velocity of rapidly advancing dendrites is measured as a function of undercooling by a High-Speed-Camera. The dendrite growth dynamics is investigated in undercooled melts of intermetallic compounds. The Al50Ni50 alloy is studied with respect to disorder trapping that leads to a disordered superlattice structure if the melt is undercooled beyond a critical undercooling. Disorder trapping is evidenced by in situ energy dispersive diffraction using synchrotron radiation of high intensity to record full diffraction pattern on levitated samples within a short time interval. Experiments on Ni2B using different processing techniques of varying the level of convection reveal convection-induced faceting of rapidly growing dendrites. Eventually, the growth velocity is measured in an undercooled melt of glass forming Cu50Zr50 alloy. A maximum in the growth velocity–undercooling relation is proved. This is understood by the fact that the temperature dependent diffusion coefficient counteracts the thermodynamic driving force for rapid growth if the temperature of the undercooled melt is approaching the temperature regime above the glass transition temperature. The analysis of this result allows for determining the activation energy of atomic attachment kinetics at the solid–liquid interface that is comparable to the activation energy of atomic diffusion as determined by independent measurements of the atomic diffusion in undercooled Cu50Zr50 alloy melt.

  14. Phase-field-lattice Boltzmann studies for dendritic growth with natural convection

    Science.gov (United States)

    Takaki, Tomohiro; Rojas, Roberto; Sakane, Shinji; Ohno, Munekazu; Shibuta, Yasushi; Shimokawabe, Takashi; Aoki, Takayuki

    2017-09-01

    Simulating dendritic growth with natural convection is challenging because of the size of the computational domain required when compared to the dendrite scale. In this study, a phase-field-lattice Boltzmann model was used to simulate dendritic growth in the presence of natural convection due to a difference in solute concentration. To facilitate and accelerate the large-scale simulation, a parallel computing code with multiple graphics processing units was developed. The effects of the computational domain size as well as those of gravity on the dendritic morphologies were examined by performing two-dimensional free dendritic growth simulations with natural convection. The effects of the gravity direction on the dendrite spacing and morphology were also investigated by simulating unidirectional solidification from multiple seeds.

  15. Selection criterion of stable dendritic growth at arbitrary Péclet numbers with convection.

    Science.gov (United States)

    Alexandrov, Dmitri V; Galenko, Peter K

    2013-06-01

    A free dendrite growth under forced fluid flow is analyzed for solidification of a nonisothermal binary system. Using an approach to dendrite growth developed by Bouissou and Pelcé [Phys. Rev. A 40, 6673 (1989)], the analysis is presented for the parabolic dendrite interface with small anisotropy of surface energy growing at arbitrary Péclet numbers. The stable growth mode is obtained from the solvability condition giving the stability criterion for the dendrite tip velocity V and dendrite tip radius ρ as a function of the growth Péclet number, flow Péclet number, and Reynolds number. In limiting cases, the obtained stability criterion presents known criteria for small and high growth Péclet numbers of the solidifying system with and without convective fluid flow.

  16. Measurements of Dendritic Growth Velocities in Undercooled Melts of Pure Nickel Under Static Magnetic Fields

    Science.gov (United States)

    Gao, Jianrong; Zhang, Zongning; Zhang, Yingjie

    2012-01-01

    Dendritic growth velocities in undercooled melts of pure Ni have been intensively studied over the past fifty years. However, the literature data are at marked variance with the prediction of the widely accepted model for rapid dendritic growth both at small and at large undercoolings. In the present work, bulk melts of pure Ni samples of high purity were undercooled by glass fluxing treatment under a static magnetic field. The recalescence processes of the samples at different undercoolings were recorded using a high-speed camera, and were modeled using a software to determine the dendritic growth velocities. The present data confirmed the effect of melt flow on dendritic growth velocities at undercoolings below 100 K. A comparison of the present data with previous measurements on a lower purity material suggested an effect of impurities on dendritic growth velocities at undercoolings larger than 200 K as well.

  17. Electroless Growth of Aluminum Dendrites in NaCl-AlCl3 Melts

    DEFF Research Database (Denmark)

    Li, Qingfeng; Hjuler, H.A.; Berg, Rolf W.

    1989-01-01

    The spontaneous growth of aluminum dendrites after deposition was observed and examined in sodium chloride-aluminumchloride melts. The concentration gradient of AlCl3 in the vicinity of the cathode surface resulting from electrolysisconstitutes a type of concentration cell with aluminum dendrites...... as electrodes. The short-circuit discharge of thecell is found to be the driving force for the growth of aluminum dendrites. Such a concentration gradient is proposed to beone of the causes for dendrite formation in the case of metal deposition....

  18. Reactive oxygen species are involved in BMP-induced dendritic growth in cultured rat sympathetic neurons.

    Science.gov (United States)

    Chandrasekaran, Vidya; Lea, Charlotte; Sosa, Jose Carlo; Higgins, Dennis; Lein, Pamela J

    2015-07-01

    Previous studies have shown that bone morphogenetic proteins (BMPs) promote dendritic growth in sympathetic neurons; however, the downstream signaling molecules that mediate the dendrite promoting activity of BMPs are not well characterized. Here we test the hypothesis that reactive oxygen species (ROS)-mediated signaling links BMP receptor activation to dendritic growth. In cultured rat sympathetic neurons, exposure to any of the three mechanistically distinct antioxidants, diphenylene iodinium (DPI), nordihydroguaiaretic acid (NGA) or desferroxamine (DFO), blocked de novo BMP-induced dendritic growth. Addition of DPI to cultures previously induced with BMP to extend dendrites caused dendritic retraction while DFO and NGA prevented further growth of dendrites. The inhibition of the dendrite promoting activity of BMPs by antioxidants was concentration-dependent and occurred without altering axonal growth or neuronal cell survival. Antioxidant treatment did not block BMP activation of SMAD 1,5 as determined by nuclear localization of these SMADs. While BMP treatment did not cause a detectable increase in intracellular ROS in cultured sympathetic neurons as assessed using fluorescent indicator dyes, BMP treatment increased the oxygen consumption rate in cultured sympathetic neurons as determined using the Seahorse XF24 Analyzer, suggesting increased mitochondrial activity. In addition, BMPs upregulated expression of NADPH oxidase 2 (NOX2) and either pharmacological inhibition or siRNA knockdown of NOX2 significantly decreased BMP-7 induced dendritic growth. Collectively, these data support the hypothesis that ROS are involved in the downstream signaling events that mediate BMP7-induced dendritic growth in sympathetic neurons, and suggest that ROS-mediated signaling positively modulates dendritic complexity in peripheral neurons. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. Numerical Simulation on Dendrite Growth During Solidification of Al-4%Cu Alloy

    Directory of Open Access Journals (Sweden)

    ZHANG Min

    2016-06-01

    Full Text Available A new two-dimensional cellular automata and finite difference (CA-FD model of dendritic growth was improved, which a perturbation function was introduced to control the growth of secondary and tertiary dendrite, the concentration of the solute was clearly defined as the liquid solute concentration and the solid-phase solute concentration in dendrite growth processes, and the eight moore calculations method was used to reduce the anisotropy caused by the shape of the grid in the process of redistribution and diffusion of solute. Single and multi equiaxed dendrites along different preferential direction, single and multi directions of columnar dendrites of Al-4% Cu alloy were simulated, as well as the distribution of liquid solute concentration and solid solute concentration. The simulation results show that the introduced perturbation function can promote the dendrite branching, liquid/solid phase solute calculation model is able to simulate the solute distribution of liquid/solid phase accurately in the process of dendritic growth, and the improved model can realize competitive growth of dendrite in any direction.

  20. A phase-field simulation of uranium dendrite growth on the cathode in the electrorefining process

    Science.gov (United States)

    Shibuta, Yasushi; Unoura, Seiji; Sato, Takumi; Shibata, Hiroki; Kurata, Masaki; Suzuki, Toshio

    2011-07-01

    The uranium dendrite growth on the cathode during the pyroprocessing of uranium is investigated using a novel phase-field model, in which electrodeposition of uranium and zirconium from the molten-salt is taken into account. The threshold concentration of zirconium in the molten salt demarcating the dendritic and planar growth is then estimated as a function of the current density. Moreover, the growth process of both the dendritic and planar electrodeposits has been demonstrated by way of varying the mobility of the phase field, which consists of the effect of attachment kinetics and diffusion.

  1. Glycan Sulfation Modulates Dendritic Cell Biology and Tumor Growth

    Directory of Open Access Journals (Sweden)

    Roland El Ghazal

    2016-05-01

    Full Text Available In cancer, proteoglycans have been found to play roles in facilitating the actions of growth factors, and effecting matrix invasion and remodeling. However, little is known regarding the genetic and functional importance of glycan chains displayed by proteoglycans on dendritic cells (DCs in cancer immunity. In lung carcinoma, among other solid tumors, tumor-associated DCs play largely subversive/suppressive roles, promoting tumor growth and progression. Herein, we show that targeting of DC glycan sulfation through mutation in the heparan sulfate biosynthetic enzyme N-deacetylase/N-sulfotransferase-1 (Ndst1 in mice increased DC maturation and inhibited trafficking of DCs to draining lymph nodes. Lymphatic-driven DC migration and chemokine (CCL21-dependent activation of a major signaling pathway required for DC migration (as measured by phospho-Akt were sensitive to Ndst1 mutation in DCs. Lewis lung carcinoma tumors in mice deficient in Ndst1 were reduced in size. Purified CD11c+ cells from the tumors, which contain the tumor-infiltrating DC population, showed a similar phenotype in mutant cells. These features were replicated in mice deficient in syndecan-4, the major heparan sulfate proteoglycan expressed on the DC surface: Tumors were growth-impaired in syndecan-4–deficient mice and were characterized by increased infiltration by mature DCs. Tumors on the mutant background also showed greater infiltration by NK cells and NKT cells. These findings indicate the genetic importance of DC heparan sulfate proteoglycans in tumor growth and may guide therapeutic development of novel strategies to target syndecan-4 and heparan sulfate in cancer.

  2. Compact seaweed growth of peritectic phase on confined, flat properitectic dendrites

    Science.gov (United States)

    Ludwig, A.; Mogeritsch, J.

    2016-12-01

    Peritectic alloys form a variety of different solidification morphologies at low growth rates. An alloy with a concentration that corresponds to the hyper-peritectic limit should show a cellular/dendritic solidification of the peritectic phase for growth velocities above the corresponding constitutional undercooling limit. However, due to nucleation retardation of the peritectic phase we observed growth of properitectic dendrites before cellular growth of the peritectic could established. The transition happened via an overgrowth of dendrites with a thin layer of peritectic phase. The observations were made using a transparent, metal-like solidifying peritectic system that was solidified directionally in thin samples. In the gap between the flat dendrites and the tubing walls, the peritectic phase grew with a compact seaweed morphology, whereas in the interdendritic spacing it formed small-curved bumps. At same distance behind the tip region, more and more polycrystalline-like objects appeared at the elongated traces of the compact seaweed morphology.

  3. A model for grain growth based on the novel description of dendrite shape

    OpenAIRE

    O. Wodo; N. Sczygiol

    2007-01-01

    We use novel description of dendritic shape in the micro solid phase growth model. The model describes evolution of both primary solid solution dendrite and eutectic that forms between arms and grains in the last stage of solidification. Obtained results show that our approach can be used in grain growth model to determine more reliable eutectic distribution. In the paper no kinetics connected with the eutectic transformation is taken into account. However, this does not affect the eutectic d...

  4. A three-dimensional cellular automaton model for dendritic growth in multi-component alloys

    International Nuclear Information System (INIS)

    Zhang Xianfei; Zhao, Jiuzhou; Jiang, Hongxiang; Zhu, Mingfang

    2012-01-01

    A three-dimensional (3-D) cellular automaton model for dendritic growth in multi-component alloys is developed. The velocity of advance of the solid/liquid (S/L) interface is calculated using the solute conservation relationship at the S/L interface. The effect of interactions between the alloying elements on the diffusion coefficient of solutes in the solid and liquid phases are considered. The model is first validated by comparing with the theoretical predictions for binary and ternary alloys, and then applied to simulate the solidification process of Al–Cu–Mg alloys by a coupling of thermodynamic and kinetic calculations. The numerical results obtained show both the free dendrite growth process as well as the directional solidification process. The calculated secondary dendrite arm spacing in the directionally solidified Al–Cu–Mg alloy is in good agreement with the experimental results. The effect of interactions between the various alloying elements on dendritic growth is discussed.

  5. ErbB2 resembles an autoinhibited invertebrate epidermal growth factor receptor

    Energy Technology Data Exchange (ETDEWEB)

    Alvarado, Diego; Klein, Daryl E.; Lemmon, Mark A.; (UPENN-MED)

    2009-09-25

    The orphan receptor tyrosine kinase ErbB2 (also known as HER2 or Neu) transforms cells when overexpressed, and it is an important therapeutic target in human cancer. Structural studies have suggested that the oncogenic (and ligand-independent) signalling properties of ErbB2 result from the absence of a key intramolecular 'tether' in the extracellular region that autoinhibits other human ErbB receptors, including the epidermal growth factor (EGF) receptor. Although ErbB2 is unique among the four human ErbB receptors, here we show that it is the closest structural relative of the single EGF receptor family member in Drosophila melanogaster (dEGFR). Genetic and biochemical data show that dEGFR is tightly regulated by growth factor ligands, yet a crystal structure shows that it, too, lacks the intramolecular tether seen in human EGFR, ErbB3 and ErbB4. Instead, a distinct set of autoinhibitory interdomain interactions hold unliganded dEGFR in an inactive state. All of these interactions are maintained (and even extended) in ErbB2, arguing against the suggestion that ErbB2 lacks autoinhibition. We therefore suggest that normal and pathogenic ErbB2 signalling may be regulated by ligands in the same way as dEGFR. Our findings have important implications for ErbB2 regulation in human cancer, and for developing therapeutic approaches that target novel aspects of this orphan receptor.

  6. Thermo-solutal growth of an anisotropic dendrite with six-fold symmetry

    Science.gov (United States)

    Alexandrov, D. V.; Galenko, P. K.

    2018-03-01

    A stable growth of dendritic crystal with the six-fold crystalline anisotropy is analyzed in a binary nonisothermal mixture. A selection criterion representing a relationship between the dendrite tip velocity and its tip diameter is derived on the basis of morphological stability analysis and solvability theory. A complete set of nonlinear equations, consisting of the selection criterion and undercooling balance condition, which determines implicit dependencies of the dendrite tip velocity and tip diameter as functions of the total undercooling, is formulated. Exact analytical solutions of these nonlinear equations are found in a parametric form. Asymptotic solutions describing the crystal growth at small Péclet numbers are determined. Theoretical predictions are compared with experimental data obtained for ice dendrites growing in binary water-ethylenglycol solutions as well as in pure water.

  7. Domain shape instabilities and dendrite domain growth in uniaxial ferroelectrics

    Science.gov (United States)

    Shur, Vladimir Ya.; Akhmatkhanov, Andrey R.

    2018-01-01

    The effects of domain wall shape instabilities and the formation of nanodomains in front of moving walls obtained in various uniaxial ferroelectrics are discussed. Special attention is paid to the formation of self-assembled nanoscale and dendrite domain structures under highly non-equilibrium switching conditions. All obtained results are considered in the framework of the unified kinetic approach to domain structure evolution based on the analogy with first-order phase transformation. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  8. Quantification of dendritic and axonal growth after injury to the auditory system of the adult cricket Gryllus bimaculatus

    Directory of Open Access Journals (Sweden)

    Alexandra ePfister

    2013-08-01

    Full Text Available Dendrite and axon growth and branching during development are regulated by a complex set of intracellular and external signals. However, the cues that maintain or influence adult neuronal morphology are less well understood. Injury and deafferentation tend to have negative effects on adult nervous systems. An interesting example of injury-induced compensatory growth is seen in the cricket, Gryllus bimaculatus. After unilateral loss of an ear in the adult cricket, auditory neurons within the central nervous system sprout to compensate for the injury. Specifically, after being deafferented, ascending neurons (AN-1 and AN-2 send dendrites across the midline of the prothoracic ganglion where they receive input from auditory afferents that project through the contralateral auditory nerve (N5. Deafferentation also triggers contralateral N5 axonal growth. In this study, we quantified AN dendritic and N5 axonal growth at 30 hours, as well as at 3, 5, 7, 14 and 20 days after deafferentation in adult crickets. Significant differences in the rates of dendritic growth between males and females were noted. In females, dendritic growth rates were non-linear; a rapid burst of dendritic extension in the first few days was followed by a plateau reached at 3 days after deafferentation. In males, however, dendritic growth rates were linear, with dendrites growing steadily over time and reaching lengths, on average, twice as long as in females. On the other hand, rates of N5 axonal growth showed no significant sexual dimorphism and were linear. Within each animal, the growth rates of dendrites and axons were not correlated, indicating that independent factors likely influence dendritic and axonal growth in response to injury in this system. Our findings provide a basis for future study of the cellular features that allow differing dendrite and axon growth patterns as well as sexually dimorphic dendritic growth in response to deafferentation.

  9. Suppressing Lithium Dendrite Growth with a Single-Component Coating.

    Science.gov (United States)

    Liu, Haodong; Zhou, Hongyao; Lee, Byoung-Sun; Xing, Xing; Gonzalez, Matthew; Liu, Ping

    2017-09-13

    A single-component coating was formed on lithium (Li) metal in a lithium iodide/organic carbonate [dimethyl carbonate (DMC) and ethylene carbonate (EC)] electrolyte. LiI chemically reacts with DMC to form lithium methyl carbonate (LMC), which precipitates and forms the chemically homogeneous coating layer on the Li surface. This coating layer is shown to enable dendrite-free Li cycling in a symmetric Li∥Li cell even at a current density of 3 mA cm -2 . Adding EC to DMC modulates the formation of LMC, resulting in a stable coating layer that is essential for long-term Li cycling stability. Furthermore, the coating can enable dendrite-free cycling after being transferred to common LiPF 6 /carbonate electrolytes, which are compatible with metal oxide cathodes.

  10. Equiaxed and columnar dendrite growth simulation in Al-7Si- Mg ternary alloys using cellular automaton method

    International Nuclear Information System (INIS)

    Chen, Rui; Xu, Qingyan; Liu, Baicheng

    2015-01-01

    In this paper, a modified cellular automaton (MCA) model allowing for the prediction of dendrite growth of Al-Si-Mg ternary alloys in two and three dimensions is presented. The growth kinetic of S/L interface is calculated based on the solute equilibrium approach. In order to describe the dendrite growth with arbitrarily crystallographic orientations, this model introduces a modified decentered octahedron algorithm for neighborhood tracking to eliminate the effect of mesh dependency on dendrite growth. The thermody namic and kinetic data needed for dendrite growth is obtained through coupling with Pandat software package in combination with thermodynamic/kinetic/equilibrium phase diagram calculation databases. The effect of interactions between various alloying elements on solute diffusion coefficient is considered in the model. This model has first been used to simulate Al-7Si (weight percent) binary dendrite growth followed by a validation using theoretical predictions. For ternary alloy, Al-7Si-0.5Mg dendrite simulation has been carried out and the effects of solute interactions on diffusion matrix as well as the differences of Si and Mg in solute distribution have been analyzed. For actual application, this model has been applied to simulate the equiaxed dendrite growth with various crystallographic orientations of Al-7Si-0.36Mg ternary alloy, and the predicted secondary dendrite arm spacing (SDAS) shows a reasonable agreement with the experimental ones. Furthermore, the columnar dendrite growth in directional solidification has also been simulated and the predicted primary dendrite arm spacing (PDAS) is in good agreement with experiments. The simulated results effectively demonstrate the abilities of the model in prediction of dendritic microstructure of Al-Si-Mg ternary alloy. (paper)

  11. Equiaxed and columnar dendrite growth simulation in Al-7Si- Mg ternary alloys using cellular automaton method

    Science.gov (United States)

    Chen, Rui; Xu, Qingyan; Liu, Baicheng

    2015-06-01

    In this paper, a modified cellular automaton (MCA) model allowing for the prediction of dendrite growth of Al-Si-Mg ternary alloys in two and three dimensions is presented. The growth kinetic of S/L interface is calculated based on the solute equilibrium approach. In order to describe the dendrite growth with arbitrarily crystallographic orientations, this model introduces a modified decentered octahedron algorithm for neighborhood tracking to eliminate the effect of mesh dependency on dendrite growth. The thermody namic and kinetic data needed for dendrite growth is obtained through coupling with Pandat software package in combination with thermodynamic/kinetic/equilibrium phase diagram calculation databases. The effect of interactions between various alloying elements on solute diffusion coefficient is considered in the model. This model has first been used to simulate Al-7Si (weight percent) binary dendrite growth followed by a validation using theoretical predictions. For ternary alloy, Al-7Si-0.5Mg dendrite simulation has been carried out and the effects of solute interactions on diffusion matrix as well as the differences of Si and Mg in solute distribution have been analyzed. For actual application, this model has been applied to simulate the equiaxed dendrite growth with various crystallographic orientations of Al-7Si-0.36Mg ternary alloy, and the predicted secondary dendrite arm spacing (SDAS) shows a reasonable agreement with the experimental ones. Furthermore, the columnar dendrite growth in directional solidification has also been simulated and the predicted primary dendrite arm spacing (PDAS) is in good agreement with experiments. The simulated results effectively demonstrate the abilities of the model in prediction of dendritic microstructure of Al-Si-Mg ternary alloy.

  12. Dendritic Zinc Growth in Acid Electrolyte: Effect of the pH

    Science.gov (United States)

    Bengoa, Leandro N.; Pary, Paola; Seré, Pablo R.; Conconi, M. Susana; Egli, Walter A.

    2018-03-01

    In this paper, dendritic growth at the edges of electrogalvanized steel strip has been studied using a specially designed rotating washer electrode which simulates the fluid dynamic conditions and the current density distribution at the steel strip edge found in a production line. The effect of electrolyte pH and current density on dendritic growth in an acidic zinc plating bath (ZnSO4 and H2SO4) was addressed. The temperature was kept constant at 60 °C. Solution pH was adjusted to 1, 2 or 3 using different amounts of H2SO4. In addition, the influence of temperature on the pH of the solution was determined. The current density was set at 40 or 60 A/dm2, similar to that used in the industry. Deposits were characterized using SEM and XRD. The results showed that pH strongly affects dendrites shape, length and texture. Furthermore, the morphology of dendrites at the washer edge and of deposits on the flat portion of the washer changed considerably as solution pH was increased from 1 to 3. It was found that the morphology of dendrites at the washer edge stems from the morphology of the deposit on its flat portion, which in turn determines their shape.

  13. Anisotropic corner diffusion as origin for dendritic growth on hexagonal substrates

    DEFF Research Database (Denmark)

    Brune, H.; Röder, H.; Bromann, K.

    1996-01-01

    and stick mechanism, form. Dendrites are characterized by preferential growth in the [2]-directions, i.e., perpendicular to A-steps. The key process for their formation has been found to be diffusion of one-fold comer atoms towards neighboring steps. Calculations with the effective medium...

  14. Effect of heat source on the growth of dendritic drying patterns

    Indian Academy of Sciences (India)

    2015-02-05

    Feb 5, 2015 ... Shining a tightly-focussed but low-powered laser beam on an absorber dispersed in a biological fluid gives rise to spectacular growth of dendritic patterns. These result from localized drying of the fluid because of efficient absorption and conduction of optical energy by the absorber. We have carried out ...

  15. Growth of tertiary dendritic arms during the transient directional solidification of hypoeutectic Pb-Sb alloys

    Science.gov (United States)

    Freitas, Emmanuelle S.; Rosa, Daniel M.; Garcia, Amauri; Spinelli, José E.

    2011-12-01

    Despite the importance of a complete characterization of dendritic patterns in castings, the availability of studies on the development of tertiary dendrite arms is scarce in the literature. In the present study, the tip cooling rate, local solidification time, primary and tertiary dendrite arm spacings have been determined in Pb-Sb alloys castings directionally solidified under unsteady-state heat flow conditions. The alloys compositions experimentally examined are widely used in the as-cast condition for the manufacture of positive and negative grids of lead-acid batteries. The initial growth of tertiary dendritic arms from the secondary branches was found to occur only for a Pb-3.5 wt% Sb alloy at cooling rates in the range 0.4-0.2 K/s, with no evidence of this spacing pattern for Pb-Sb alloys having lower solute content. Tertiary dendritic branches have been observed along the entire casting lengths for alloys of the Pb-Sb hypoeutectic range having compositions higher than 4.0 wt% Sb. It is shown that a power function experimental law with a characteristic -0.55 exponent is able to characterize the tertiary spacing evolution with the solidification cooling rate for alloys compositions ≥4.0 wt% Sb. The only exception was the Pb-3.5 wt% Sb alloy for which λ 3 exhibited significant lower values when compared with the experimental values obtained for the other Pb-Sb alloys for a same solidification cooling rate.

  16. Crystal nucleation and dendrite growth of metastable phases in undercooled melts

    International Nuclear Information System (INIS)

    Herlach, Dieter

    2011-01-01

    Research highlights: → Homogenous nucleation. → Effects of convection on dendrite growth kinetics. → Description of disorder trapping validated by experiment. - Abstract: An undercooled melt possesses an enhanced free enthalpy that opens up the possibility to crystallize metastable crystalline solids in competition with their stable counterparts. Crystal nucleation selects the crystallographic phase whereas the growth dynamics controls microstructure evolution. We apply containerless processing techniques such as electromagnetic and electrostatic levitation to containerlesss undercool and solidify metallic melts. Owing to the complete avoidance of heterogeneous nucleation on container-walls a large undercooling range becomes accessible with the extra benefit that the freely suspended drop is direct accessible for in situ observation of crystallization far away from equilibrium. Results of investigations of maximum undercoolability on pure zirconium are presented showing the limit of maximum undercoolability set by the onset of homogeneous nucleation. Rapid dendrite growth is measured as a function of undercooling by a high-speed camera and analysed within extended theories of non-equilibrium solidification. In such both supersaturated solid solutions and disordered superlattice structure of intermetallics are formed at high growth velocities. A sharp interface theory of dendrite growth is capable to describe the non-equilibrium solidification phenomena during rapid crystallization of deeply undercooled melts. Eventually, anomalous growth behaviour of Al-rich Al-Ni alloys is presented, which may be caused by forced convection.

  17. A model for grain growth based on the novel description of dendrite shape

    Directory of Open Access Journals (Sweden)

    O. Wodo

    2007-12-01

    Full Text Available We use novel description of dendritic shape in the micro solid phase growth model. The model describes evolution of both primary solid solution dendrite and eutectic that forms between arms and grains in the last stage of solidification. Obtained results show that our approach can be used in grain growth model to determine more reliable eutectic distribution. In the paper no kinetics connected with the eutectic transformation is taken into account. However, this does not affect the eutectic distribution because at the beginning of eutectic reaction all liquid phase was assumed to fully transform into eutectic. Results for solid phase growth model based on this description are presented. The obtained results of eutectic distribution are especially important in the hypoeutectic alloy solidification case, where the eutectic grains grow between formed solid solution grains. Thus, the distribution of solid solution grain becomes crucial due to its influence on the delay in solid fraction increase of eutectic grains.

  18. Microscopic properties of lithium, sodium, and magnesium battery anode materials related to possible dendrite growth

    International Nuclear Information System (INIS)

    Jäckle, Markus; Groß, Axel

    2014-01-01

    Lithium and magnesium exhibit rather different properties as battery anode materials with respect to the phenomenon of dendrite formation which can lead to short-circuits in batteries. Diffusion processes are the key to understanding structure forming processes on surfaces. Therefore, we have determined adsorption energies and barriers for the self-diffusion on Li and Mg using periodic density functional theory calculations and contrasted the results to Na which is also regarded as a promising electrode material in batteries. According to our calculations, magnesium exhibits a tendency towards the growth of smooth surfaces as it exhibits lower diffusion barriers than lithium and sodium, and as an hcp metal it favors higher-coordinated configurations in contrast to the bcc metals Li and Na. These characteristic differences are expected to contribute to the unequal tendencies of these metals with respect to dendrite growth

  19. Class 3 Semaphorin Mediates Dendrite Growth in Adult Newborn Neurons through Cdk5/FAK Pathway

    Science.gov (United States)

    Sohn, Jae Ho; Tan, Terence; Song, Hongjun; Ming, Guo-li; Goh, Eyleen L. K.

    2013-01-01

    Class 3 semaphorins are well-known axonal guidance cues during the embryonic development of mammalian nervous system. However, their activity on postnatally differentiated neurons in neurogenic regions of adult brains has not been characterized. We found that silencing of semaphorin receptors neuropilins (NRP) 1 or 2 in neural progenitors at the adult mouse dentate gyrus resulted in newly differentiated neurons with shorter dendrites and simpler branching in vivo. Tyrosine phosphorylation (Tyr 397) and serine phosphorylation (Ser 732) of FAK were essential for these effects. Semaphorin 3A and 3F mediate serine phosphorylation of FAK through the activation of Cdk5. Silencing of either Cdk5 or FAK in newborn neurons phenocopied the defects in dendritic development seen upon silencing of NRP1 or NRP2. Furthermore, in vivo overexpression of Cdk5 or FAK rescued the dendritic phenotypes seen in NRP1 and NRP2 deficient neurons. These results point to a novel role for class 3 semaphorins in promoting dendritic growth and branching during adult hippocampal neurogenesis through the activation of Cdk5-FAK signaling pathway. PMID:23762397

  20. Class 3 semaphorin mediates dendrite growth in adult newborn neurons through Cdk5/FAK pathway.

    Directory of Open Access Journals (Sweden)

    Teclise Ng

    Full Text Available Class 3 semaphorins are well-known axonal guidance cues during the embryonic development of mammalian nervous system. However, their activity on postnatally differentiated neurons in neurogenic regions of adult brains has not been characterized. We found that silencing of semaphorin receptors neuropilins (NRP 1 or 2 in neural progenitors at the adult mouse dentate gyrus resulted in newly differentiated neurons with shorter dendrites and simpler branching in vivo. Tyrosine phosphorylation (Tyr 397 and serine phosphorylation (Ser 732 of FAK were essential for these effects. Semaphorin 3A and 3F mediate serine phosphorylation of FAK through the activation of Cdk5. Silencing of either Cdk5 or FAK in newborn neurons phenocopied the defects in dendritic development seen upon silencing of NRP1 or NRP2. Furthermore, in vivo overexpression of Cdk5 or FAK rescued the dendritic phenotypes seen in NRP1 and NRP2 deficient neurons. These results point to a novel role for class 3 semaphorins in promoting dendritic growth and branching during adult hippocampal neurogenesis through the activation of Cdk5-FAK signaling pathway.

  1. Chlorpyrifos exerts opposing effects on axonal and dendritic growth in primary neuronal cultures

    International Nuclear Information System (INIS)

    Howard, Angela S.; Bucelli, Robert; Jett, David A.; Bruun, Donald; Yang, Dongren; Lein, Pamela J.

    2005-01-01

    Evidence that children are widely exposed to organophosphorus pesticides (OPs) and that OPs cause developmental neurotoxicity in animal models raises significant concerns about the risks these compounds pose to the developing human nervous system. Critical to assessing this risk is identifying specific neurodevelopmental events targeted by OPs. Observations that OPs alter brain morphometry in developing rodents and inhibit neurite outgrowth in neural cell lines suggest that OPs perturb neuronal morphogenesis. However, an important question yet to be answered is whether the dysmorphogenic effect of OPs reflects perturbation of axonal or dendritic growth. We addressed this question by quantifying axonal and dendritic growth in primary cultures of embryonic rat sympathetic neurons derived from superior cervical ganglia (SCG) following in vitro exposure to chlorpyrifos (CPF) or its metabolites CPF-oxon (CPFO) and trichloropyridinol (TCP). Axon outgrowth was significantly inhibited by CPF or CPFO, but not TCP, at concentrations ≥0.001 μM or 0.001 nM, respectively. In contrast, all three compounds enhanced BMP-induced dendritic growth. Acetylcholinesterase was inhibited only by the highest concentrations of CPF (≥1 μM) and CPFO (≥1 nM); TCP had no effect on this parameter. In summary, these compounds perturb neuronal morphogenesis via opposing effects on axonal and dendritic growth, and both effects are independent of acetylcholinesterase inhibition. These findings have important implications for current risk assessment practices of using acetylcholinesterase inhibition as a biomarker of OP neurotoxicity and suggest that OPs may disrupt normal patterns of neuronal connectivity in the developing nervous system

  2. Centella asiatica (L. Leaf Extract Treatment During the Growth Spurt Period Enhances Hippocampal CA3 Neuronal Dendritic Arborization in Rats

    Directory of Open Access Journals (Sweden)

    K. G. Mohandas Rao

    2006-01-01

    Full Text Available Centella asiatica (CeA is a creeping plant growing in damp places in India and other Asian countries. The leaves of CeA are used for memory enhancement in the Ayurvedic system of medicine, an alternative system of medicine in India. In this study, we have investigated the effect during the rat growth spurt period of CeA fresh leaf extract treatment on the dendritic morphology of hippocampal CA3 neurons, one of the regions of the brain concerned with learning and memory. Neonatal rat pups (7 days old were fed with 2, 4 or 6 ml kg−1 body weight of fresh leaf extract of CeA for 2, 4 or 6 weeks. After the treatment period the rats were killed, their brains were removed and the hippocampal neurons were impregnated with silver nitrate (Golgi staining. Hippocampal CA3 neurons were traced using a camera lucida, and dendritic branching points (a measure of dendritic arborization and intersections (a measure of dendritic length were quantified. These data were compared with data for age-matched control rats. The results showed a significant increase in the dendritic length (intersections and dendritic branching points along the length of both apical and basal dendrites in rats treated with 4 and 6 ml kg−1 body weight per day of CeA for longer periods of time (i.e. 4 and 6 weeks. We conclude that the constituents/active principles present in CeA fresh leaf extract have a neuronal dendritic growth stimulating property; hence, the extract can be used for enhancing neuronal dendrites in stress and neurodegenerative and memory disorders.

  3. Enhancement of Amygdaloid Neuronal Dendritic Arborization by Fresh Leaf Juice of Centella asiatica (Linn during Growth Spurt Period in Rats

    Directory of Open Access Journals (Sweden)

    K. G. Mohandas Rao

    2009-01-01

    Full Text Available Centella asiatica (CeA is a creeping herb, growing in moist places in India and other Asian Countries. Ayurvedic system of medicine, an alternate system of medicine in India, uses leaves of CeA for memory enhancement. Here, we have investigated the role of CeA fresh leaf juice treatment during growth spurt period of rats on dendritic morphology of amygdaloid neurons, one of the regions concerned with learning and memory. The present study was conducted on neonatal rat pups. The rat pups (7-days-old were fed with 2, 4 and 6 ml/kg body of fresh leaf juice of CeA for 2, 4 and 6 weeks. After the treatment period, the rats were killed, brains removed and amygdaloid neurons impregnated with Silver nitrate (Golgi staining. Amygdaloid neurons were traced using camera lucida and dendritic branching points (a measure of dendritic arborization and intersections (a measure dendritic length quantified. These data were compared with those of age-matched control rats. The results showed a significant increase in dendritic length (intersections and dendritic branching points along the length of dendrites of the amygdaloid neurons of rats treated with 4 and 6 ml/kg body weight/day of CeA for longer periods of time (i.e. 4 and 6 weeks. We conclude that constituents/active principles present in CeA fresh leaf juice has neuronal dendritic growth stimulating property; hence it can be used for enhancing neuronal dendrites in stress and other neurodegenerative and memory disorders.

  4. Influence of Forced Flow on the Dendritic Growth of Fe-C Alloy: 3D vs 2D Simulation

    Science.gov (United States)

    Wang, Weiling; Wang, Zhaohui; Luo, Sen; Ji, Cheng; Zhu, Miaoyong

    2017-12-01

    A 3D parallel cellular automaton-finite volume method (CA-FVM) model was used to simulate the equiaxed dendritic growth of an Fe-0.82 wt pct C alloy with xy- in- out and xyz- in- out type forced flows and the columnar dendritic growth with y- in- out type forced flow. In addition, the similarities and differences between the results of the 3D and 2D models are discussed and summarized in detail. The capabilities of the 3D and 2D CA-FVM models to predict the dendritic growth of the alloy with forced flow are validated through comparison with the boundary layer correction and Oseen-Ivanstov models, respectively. Because the forced flow can pass around perpendicular arms of the dendrites, the secondary arms at the sides upstream from the perpendicular arms are more developed than those on the upstream side of the upstream arms, especially at higher inlet velocities. In addition, compared to the xy- in- out case, the growth of the downstream arms is less inhibited and the secondary arms are more developed in the xyz- in- out case because of the greater lateral flow around their tips. Compared to the 3D case, the 2D equiaxed dendrites are more asymmetrical and lack secondary arms because of the thicker solute envelope. In the 3D case, the columnar dendrites on the upstream side (left one) are promoted, while the middle and downstream dendrites are inhibited in sequence. However, the sequential inhibition starts on the upstream side in the 2D case. This is mainly because the melt can pass around the upstream branch in 3D space. However, it can only climb over the upstream tip in 2D space. Additionally, the secondary arms show upstream development, which is more significant with increasing inlet velocity. The level of development of the secondary arms is also affected by the decay of the forced flow in the flow direction.

  5. Detachment of secondary dendrite arm in a directionally solidified Sn-Ni peritectic alloy under deceleration growth condition

    Science.gov (United States)

    Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie; Fu, Hengzhi

    2016-06-01

    In order to better understand the detachment mechanism of secondary dendrite arm during peritectic solidification, the detachment of secondary dendrite arm from the primary dendrite arms in directionally solidified Sn-36at.%Ni peritectic alloys is investigated at different deceleration rates. Extensive detachment of secondary dendrite arms from primary stem is observed below peritectic reaction temperature TP. And an analytical model is established to characterize the detachment process in terms of the secondary dendrite arm spacing λ2, the root radius of detached arms and the specific surface area (SV) of dendrites. It is found that the detachment mechanism is caused by not only curvature difference between the tips and roots of secondary branches, but also that between the thicker secondary branches and the thinner ones. Besides, this detachment process is significantly accelerated by the temperature gradient zone melting (TGZM) effect during peritectic solidification. It is demonstrated that the reaction constant (f) which is used to characterize the kinetics of peritectic reaction is crucial for the determination of the detachment process. The value of f not only changes with growth rate but also with solidification time at a given deceleration rate. In conclusion, these findings help the better understanding of the detachment mechanism.

  6. Thermoelectric magnetohydrodynamic effects on the crystal growth rate of undercooled Ni dendrites

    Science.gov (United States)

    Pericleous, K.

    2018-01-01

    In the undercooled solidification of pure metals, the dendrite tip velocity has been shown experimentally to have a strong dependence on the intensity of an external magnetic field, exhibiting several maxima and minima. In the experiments conducted in China, the undercooled solidification dynamics of pure Ni was studied using the glass fluxing method. Visual recordings of the progress of solidification are compared at different static fields up to 6 T. The introduction of microscopic convective transport through thermoelectric magnetohydrodynamics is a promising explanation for the observed changes of tip velocities. To address this problem, a purpose-built numerical code was used to solve the coupled equations representing the magnetohydrodynamic, thermal and solidification mechanisms. The underlying phenomena can be attributed to two competing flow fields, which were generated by orthogonal components of the magnetic field, parallel and transverse to the direction of growth. Their effects are either intensified or damped out with increasing magnetic field intensity, leading to the observed behaviour of the tip velocity. The results obtained reflect well the experimental findings. This article is part of the theme issue ‘From atomistic interfaces to dendritic patterns’. PMID:29311205

  7. Thermoelectric magnetohydrodynamic effects on the crystal growth rate of undercooled Ni dendrites

    Science.gov (United States)

    Kao, A.; Gao, J.; Pericleous, K.

    2018-01-01

    In the undercooled solidification of pure metals, the dendrite tip velocity has been shown experimentally to have a strong dependence on the intensity of an external magnetic field, exhibiting several maxima and minima. In the experiments conducted in China, the undercooled solidification dynamics of pure Ni was studied using the glass fluxing method. Visual recordings of the progress of solidification are compared at different static fields up to 6 T. The introduction of microscopic convective transport through thermoelectric magnetohydrodynamics is a promising explanation for the observed changes of tip velocities. To address this problem, a purpose-built numerical code was used to solve the coupled equations representing the magnetohydrodynamic, thermal and solidification mechanisms. The underlying phenomena can be attributed to two competing flow fields, which were generated by orthogonal components of the magnetic field, parallel and transverse to the direction of growth. Their effects are either intensified or damped out with increasing magnetic field intensity, leading to the observed behaviour of the tip velocity. The results obtained reflect well the experimental findings. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  8. Solution of Dendritic Growth in Steel by the Novel Point Automata Method

    International Nuclear Information System (INIS)

    Lorbiecka, A Z; Šarler, B

    2012-01-01

    The aim of this paper is the simulation of dendritic growth in steel in two dimensions by a coupled deterministic continuum mechanics heat and species transfer model and a stochastic localized phase change kinetics model taking into account the undercooling, curvature, kinetic, and thermodynamic anisotropy. The stochastic model receives temperature and concentration information from the deterministic model and the deterministic heat, and species diffusion equations receive the solid fraction information from the stochastic model. The heat and species transfer models are solved on a regular grid by the standard explicit Finite Difference Method (FDM). The phase-change kinetics model is solved by a novel Point Automata (PA) approach. The PA method was developed [1] in order to circumvent the mesh anisotropy problem, associated with the classical Cellular Automata (CA) method. The PA approach is established on randomly distributed points and neighbourhood configuration, similar as appears in meshless methods. A comparison of the PA and CA methods is shown. It is demonstrated that the results with the new PA method are not sensitive to the crystallographic orientations of the dendrite.

  9. A PKC-dependent recruitment of MMP-2 controls semaphorin-3A growth-promoting effect in cortical dendrites.

    Directory of Open Access Journals (Sweden)

    Bertrand Gonthier

    Full Text Available There is increasing evidence for a crucial role of proteases and metalloproteinases during axon growth and guidance. In this context, we recently described a functional link between the chemoattractive Sema3C and Matrix metalloproteinase 3 (MMP3. Here, we provide data demonstrating the involvement of MMP-2 to trigger the growth-promoting effect of Sema3A in cortical dendrites. The in situ analysis of MMP-2 expression and activity is consistent with a functional growth assay demonstrating in vitro that the pharmacological inhibition of MMP-2 reduces the growth of cortical dendrites in response to Sema3A. Hence, our results suggest that the selective recruitment and activation of MMP-2 in response to Sema3A requires a PKC alpha dependent mechanism. Altogether, we provide a second set of data supporting MMPs as effectors of the growth-promoting effects of semaphorins, and we identify the potential signalling pathway involved.

  10. Depletion of cutaneous macrophages and dendritic cells promotes growth of basal cell carcinoma in mice.

    Directory of Open Access Journals (Sweden)

    Simone König

    Full Text Available Basal cell carcinoma (BCC belongs to the group of non-melanoma skin tumors and is the most common tumor in the western world. BCC arises due to mutations in the tumor suppressor gene Patched1 (Ptch. Analysis of the conditional Ptch knockout mouse model for BCC reveals that macrophages and dendritic cells (DC of the skin play an important role in BCC growth restraining processes. This is based on the observation that a clodronate-liposome mediated depletion of these cells in the tumor-bearing skin results in significant BCC enlargement. The depletion of these cells does not modulate Ki67 or K10 expression, but is accompanied by a decrease in collagen-producing cells in the tumor stroma. Together, the data suggest that cutaneous macrophages and DC in the tumor microenvironment exert an antitumor effect on BCC.

  11. Design, fabrication and testing of an apparatus for in-situ investigation of free dendritic growth under an applied electric field

    Science.gov (United States)

    Nasresfahani, Mohamad Reza; Niroumand, Behzad; Kermanpur, Ahmad

    2015-04-01

    Modification of dendritic growth of primary phase during solidification has been a continuous quest for materials researchers during last decades. Use of electric current during solidification has been recently proposed as a suitable tool for refinement and modification of dendritic microstructures. Mechanisms by which an electric field could affect a dendritic morphology are not entirely clear as it is difficult to study the solidification phenomena during cooling. This paper reports the design, fabrication and testing of an instrument for in-situ study of the dendritic growth of transparent model materials in the presence of an applied electric field. The system consists of an isothermal bath, a growth chamber and an optical and imaging system. The structure of the growth chamber is designed to allow the growth of only a single dendrite under the applied electric field. In contrast to some previously made instruments which use two orthogonally placed cameras to take care of dendrite tilting or rotation errors, in this research a mathematical approach for calculating the actual dimensions and growth velocity of the dendrite using only one camera was suggested. This greatly simplifies the structure of the instrument. Solidification of a transparent model material, i.e. a succinonitrile alloy, was investigated as a case study under different applied electric fields using the instrument. The results of the study showed a reduction in the dendrite tip velocity in the presence of the electric field.

  12. Effect of Temperature and Fluid Flow on Dendrite Growth During Solidification of Al-3 Wt Pct Cu Alloy by the Two-Dimensional Cellular Automaton Method

    Science.gov (United States)

    Gu, Cheng; Wei, Yanhong; Liu, Renpei; Yu, Fengyi

    2017-12-01

    A two-dimensional cellular automaton-finite volume model was developed to simulate dendrite growth of Al-3 wt pct Cu alloy during solidification to investigate the effect of temperature and fluid flow on dendrite morphology, solute concentration distribution, and dendrite growth velocity. Different calculation conditions that may influence the results of the simulation, including temperature and flow, were considered. The model was also employed to study the effect of different undercoolings, applied temperature fields, and forced flow velocities on solute segregation and dendrite growth. The initial temperature and fluid flow have a significant impact on the dendrite morphologies and solute profiles during solidification. The release of energy is operated with solidification and results in the increase of temperature. A larger undercooling leads to larger solute concentration near the solid/liquid interface and solute concentration gradient at the same time-step. Solute concentration in the solid region tends to increase with the increase of undercooling. Four vortexes appear under the condition when natural flow exists: the two on the right of the dendrite rotate clockwise, and those on the left of the dendrite rotate counterclockwise. With the increase of forced flow velocity, the rejected solute in the upstream region becomes easier to be washed away and enriched in the downstream region, resulting in acceleration of the growth of the dendrite in the upstream and inhibiting the downstream dendrite growth. The dendrite perpendicular to fluid flow shows a coarser morphology in the upstream region than that of the downstream. Almost no secondary dendrite appears during the calculation process.

  13. Control of dendrite growth by a magnetic field during directional solidification

    Science.gov (United States)

    Dai, Yanchao; Du, Dafan; Hou, Long; Gagnoud, Annie; Ren, Zhongming; Fautrelle, Yves; Moreau, Rene; Li, Xi

    2016-04-01

    In this work, the alignment behavior of three kinds of dendrites (Al3Ni, α-Al and Al2Cu dendrites) with a remarkable crystalline anisotropy during directional solidification under an axial magnetic field is studied by the EBSD technology. Experimental results reveal that the magnetic field is capable of tailoring the dendrite alignment during directional solidification. Further, based on the crystalline anisotropy, a method to control the dendrite alignment by adjusting the angle between the magnetic field and the solidification direction is proposed.

  14. Activity-Dependent Dendritic Spine Shrinkage and Growth Involve Downregulation of Cofilin via Distinct Mechanisms

    Science.gov (United States)

    Calabrese, Barbara; Saffin, Jean-Michel; Halpain, Shelley

    2014-01-01

    A current model posits that cofilin-dependent actin severing negatively impacts dendritic spine volume. Studies suggested that increased cofilin activity underlies activity-dependent spine shrinkage, and that reduced cofilin activity induces activity-dependent spine growth. We suggest instead that both types of structural plasticity correlate with decreased cofilin activity. However, the mechanism of inhibition determines the outcome for spine morphology. RNAi in rat hippocampal cultures demonstrates that cofilin is essential for normal spine maintenance. Cofilin-F-actin binding and filament barbed-end production decrease during the early phase of activity-dependent spine shrinkage; cofilin concentration also decreases. Inhibition of the cathepsin B/L family of proteases prevents both cofilin loss and spine shrinkage. Conversely, during activity-dependent spine growth, LIM kinase stimulates cofilin phosphorylation, which activates phospholipase D-1 to promote actin polymerization. These results implicate novel molecular mechanisms and prompt a revision of the current model for how cofilin functions in activity-dependent structural plasticity. PMID:24740405

  15. Neuronal PTEN deletion in adult cortical neurons triggers progressive growth of cell bodies, dendrites, and axons.

    Science.gov (United States)

    Gallent, Erin A; Steward, Oswald

    2018-05-01

    Deletion of the phosphatase and tensin (PTEN) gene in neonatal mice leads to enlargement of the cell bodies of cortical motoneurons (CMNs) in adulthood (Gutilla et al., 2016). Here, we assessed whether PTEN deletion in adult mice would trigger growth of mature neurons. PTEN was deleted by injecting AAV-Cre into the sensorimotor cortex of adult transgenic mice with a lox-P flanked exon 5 of the PTEN gene and Cre-dependent reporter gene tdTomato. PTEN-deleted CMN's identified by tdT expression and retrograde labeling with fluorogold (FG) were significantly enlarged four months following PTEN deletion, and continued to increase in size through the latest time intervals examined (12-15 months post-deletion). Sholl analyses of tdT-positive pyramidal neurons revealed increases in dendritic branches at 6 months following adult PTEN deletion, and greater increases at 12 months. 12 months after adult PTEN deletion, axons in the medullary pyramids were significantly larger and G-ratios were higher. Mice with PTEN deletion exhibited no overt neurological symptoms and no seizures. Assessment of motor function on the rotarod and cylinder test revealed slight impairment of coordination with unilateral deletion; however, mice with bilateral PTEN deletion in the motor cortex performed better than controls on the rotarod at 8 and 10 months post-deletion. Our findings demonstrate that robust neuronal growth can be induced in fully mature cortical neurons long after the developmental period has ended and that this continuous growth occurs without obvious functional impairments. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Incorporating an extended dendritic growth model into the CAFE model for rapidly solidified non-dilute alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jie; Wang, Bo [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Zhao, Shunli [Research Institute, Baoshan Iron & Steel Co., Ltd, Shanghai 201900 (China); Wu, Guangxin [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Zhang, Jieyu, E-mail: zjy6162@staff.shu.edu.cn [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Yang, Zhiliang [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China)

    2016-05-25

    We have extended the dendritic growth model first proposed by Boettinger, Coriell and Trivedi (here termed EBCT) for microstructure simulations of rapidly solidified non-dilute alloys. The temperature-dependent distribution coefficient, obtained from calculations of phase equilibria, and the continuous growth model (CGM) were adopted in the present EBCT model to describe the solute trapping behaviors. The temperature dependence of the physical properties, which were not used in previous dendritic growth models, were also considered in the present EBCT model. These extensions allow the present EBCT model to be used for microstructure simulations of non-dilute alloys. The comparison of the present EBCT model with the BCT model proves that the considerations of the distribution coefficient and physical properties are necessary for microstructure simulations, especially for small particles with high undercoolings. Finally, the EBCT model was incorporated into the cellular automaton-finite element (CAFE) model to simulate microstructures of gas-atomized ASP30 high speed steel particles that were then compared with experimental results. Both the simulated and experimental results reveal that a columnar dendritic microstructure preferentially forms in small particles and an equiaxed microstructure forms otherwise. The applications of the present EBCT model provide a convenient way to predict the microstructure of non-dilute alloys. - Highlights: • A dendritic growth model was developed considering non-equilibrium distribution coefficient. • The physical properties with temperature dependence were considered in the extended model. • The extended model can be used to non-dilute alloys and the extensions are necessary in small particles. • Microstructure of ASP30 steel was investigated using the present model and verified by experiment.

  17. Cellular Automaton Study of Hydrogen Porosity Evolution Coupled with Dendrite Growth During Solidification in the Molten Pool of Al-Cu Alloys

    Science.gov (United States)

    Gu, Cheng; Wei, Yanhong; Yu, Fengyi; Liu, Xiangbo; She, Lvbo

    2017-09-01

    Welding porosity defects significantly reduce the mechanical properties of welded joints. In this paper, the hydrogen porosity evolution coupled with dendrite growth during solidification in the molten pool of Al-4.0 wt pct Cu alloy was modeled and simulated. Three phases, including a liquid phase, a solid phase, and a gas phase, were considered in this model. The growth of dendrites and hydrogen gas pores was reproduced using a cellular automaton (CA) approach. The diffusion of solute and hydrogen was calculated using the finite difference method (FDM). Columnar and equiaxed dendrite growth with porosity evolution were simulated. Competitive growth between different dendrites and porosities was observed. Dendrite morphology was influenced by porosity formation near dendrites. After solidification, when the porosities were surrounded by dendrites, they could not escape from the liquid, and they made pores that existed in the welded joints. With the increase in the cooling rate, the average diameter of porosities decreased, and the average number of porosities increased. The average diameter of porosities and the number of porosities in the simulation results had the same trend as the experimental results.

  18. Tocotrienol-adjuvanted dendritic cells inhibit tumor growth and metastasis: a murine model of breast cancer.

    Directory of Open Access Journals (Sweden)

    Sitti Rahma Abdul Hafid

    Full Text Available Tocotrienol-rich fraction (TRF from palm oil is reported to possess anti-cancer and immune-enhancing effects. In this study, TRF supplementation was used as an adjuvant to enhance the anti-cancer effects of dendritic cells (DC-based cancer vaccine in a syngeneic mouse model of breast cancer. Female BALB/c mice were inoculated with 4T1 cells in mammary pad to induce tumor. When the tumor was palpable, the mice in the experimental groups were injected subcutaneously with DC-pulsed with tumor lysate (TL from 4T1 cells (DC+TL once a week for three weeks and fed daily with 1 mg TRF or vehicle. Control mice received unpulsed DC and were fed with vehicle. The combined therapy of using DC+TL injections and TRF supplementation (DC+TL+TRF inhibited (p<0.05 tumor growth and metastasis. Splenocytes from the DC+TL+TRF group cultured with mitomycin-C (MMC-treated 4T1 cells produced higher (p<0.05 levels of IFN-γ and IL-12. The cytotoxic T-lymphocyte (CTL assay also showed enhanced tumor-specific killing (p<0.05 by CD8(+ T-lymphocytes isolated from mice in the DC+TL+TRF group. This study shows that TRF has the potential to be used as an adjuvant to enhance effectiveness of DC-based vaccines.

  19. Anomaly in dendritic growth data — effect of density change upon solidification

    Science.gov (United States)

    Pines, Vladimir; Chait, Arnon; Zlatkowski, Marianne

    1996-12-01

    We examine recent dendritic growth data obtained by Glicksman and co-workers [M.E. Glicksman, M.B. Koss and E.A. Winsa, Phys. Rev. Lett. 73 (1994) 573; M.E. Glicksman, M.B. Koss, L.T. Bushnell, J.C. LaCombe and E.A. Winsa, ISIJ Int. 35 (1995) 1216; MRS Fall Meeting, Symp. P, Boston, MA, 1995, in press; M.E. Glicksman, M.B. Koss, L.T. Bushnell and J.C. LaCombe, in: Modelling of Casting, Welding and Advanced Solidification Processes VII, Eds. M. Cross and J. Campbell, (The Minerals, Metals and Materials Society, 1995); private communication] in microgravity. These authors have pointed out an anomaly in the data, when compared with theoretical predictions. In particular, a systematic deviation of the growth Péclet number from an Ivantsov's theory was noted at the intermediate supercooling range. This work considers effects due to density change upon solidification. This requires a careful reexamination of the definition of material parameters, and an evaluation of effects due to the solidification-induced fluid flow ("Stefan wind"). A consistent application of carefully obtained material parameters clearly eliminates the discrepancy between the theory and experimental data. However, the effect of fluid flow due to the solid-melt density change is shown to be of minor importance to the particular experiment and material under consideration. We conclude by presenting an Ivantsov's theory modified for the wall proximity effect and corrected for density change upon solidification that matches the entire range of supercooling levels used in Glicksman's experiments.

  20. Dual effect of serotonin on the dendritic growth of cultured hippocampal neurons: Involvement of 5-HT1A and 5-HT7 receptors.

    Science.gov (United States)

    Rojas, P S; Aguayo, F; Neira, D; Tejos, M; Aliaga, E; Muñoz, J P; Parra, C S; Fiedler, J L

    2017-12-01

    Serotonin acts through its receptors (5-HTRs) to shape brain networks during development and modulates essential functions in mature brain. The 5-HT 1A R is mainly located at soma of hippocampal neurons early during brain development and its expression gradually shifts to dendrites during postnatal development. The 5-HT 7 R expressed early during hippocampus development, shows a progressive reduction in its expression postnatally. Considering these changes during development, we evaluated in cultured hippocampal neurons whether the 5-HT 1A R and 5-HT 7 R change their expression, modulate dendritic growth, and activate signaling pathways such as ERK1/2, AKT/GSK3β and LIMK/cofilin, which may sustain dendrite outgrowth by controlling cytoskeleton dynamics. We show that mRNA levels of both receptors increase between 2 and 7 DIV; however only protein levels of 5-HT 7 R increase significantly at 7 DIV. The 5-HT 1A R is preferentially distributed in the soma, while 5-HT 7 R displays a somato-dendritic localization at 7 DIV. Through stimulation with 5-HT at 7 DIV during 24h and using specific antagonists, we determined that 5-HT 1A R decreases the number of primary and secondary dendrites and restricts the growth of primary dendrites. The activation of 5-HT 1A R and 5-HT 7 R promotes the growth of short secondary dendrites and triggers ERK1/2 and AKT phosphorylation through MEK and PI3K activation respectively; without changes in the phosphorylation of LIMK and cofilin. We conclude that 5-HT 1A R restricts dendritogenesis and outgrowth of primary dendrites, but that both 5-HT 1A R and 5-HT 7 R promote secondary dendrite outgrowth. These data support the role of 5-HT in neuronal outgrowth during development and provide insight into cellular basis of neurodevelopmental disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Thermo-solutal and kinetic modes of stable dendritic growth with different symmetries of crystalline anisotropy in the presence of convection

    Science.gov (United States)

    Alexandrov, Dmitri V.; Galenko, Peter K.; Toropova, Lyubov V.

    2018-01-01

    Motivated by important applications in materials science and geophysics, we consider the steady-state growth of anisotropic needle-like dendrites in undercooled binary mixtures with a forced convective flow. We analyse the stable mode of dendritic evolution in the case of small anisotropies of growth kinetics and surface energy for arbitrary Péclet numbers and n-fold symmetry of dendritic crystals. On the basis of solvability and stability theories, we formulate a selection criterion giving a stable combination between dendrite tip diameter and tip velocity. A set of nonlinear equations consisting of the solvability criterion and undercooling balance is solved analytically for the tip velocity V and tip diameter ρ of dendrites with n-fold symmetry in the absence of convective flow. The case of convective heat and mass transfer mechanisms in a binary mixture occurring as a result of intensive flows in the liquid phase is detailed. A selection criterion that describes such solidification conditions is derived. The theory under consideration comprises previously considered theoretical approaches and results as limiting cases. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  2. Chronic Ampakine Treatments Stimulate Dendritic Growth and Promote Learning in Middle-Aged Rats

    Science.gov (United States)

    Lauterborn, Julie C.; Palmer, Linda C.; Jia, Yousheng; Pham, Danielle T.; Hou, Bowen; Wang, Weisheng; Trieu, Brian H.; Cox, Conor D.; Kantorovich, Svetlana

    2016-01-01

    Positive allosteric modulators of AMPA-type glutamate receptors (ampakines) have been shown to rescue synaptic plasticity and reduce neuropathology in rodent models of cognitive disorders. Here we tested whether chronic ampakine treatment offsets age-related dendritic retraction in middle-aged (MA) rats. Starting at 10 months of age, rats were housed in an enriched environment and given daily treatment with a short half-life ampakine or vehicle for 3 months. Dendritic branching and spine measures were collected from 3D reconstructions of Lucifer yellow-filled CA1 pyramidal cells. There was a substantial loss of secondary branches, relative to enriched 2.5-month-old rats, in apical and basal dendritic fields of vehicle-treated, but not ampakine-treated, 13-month-old rats. Baseline synaptic responses in CA1 were only subtly different between the two MA groups, but long-term potentiation was greater in ampakine-treated rats. Unsupervised learning of a complex environment was used to assess treatment effects on behavior. Vehicle- and drug-treated rats behaved similarly during a first 30 min session in the novel environment but differed markedly on subsequent measures of long-term memory. Markov sequence analysis uncovered a clear increase in the predictability of serial movements between behavioral sessions 2 and 3 in the ampakine, but not vehicle, group. These results show that a surprising degree of dendritic retraction occurs by middle age and that this can be mostly offset by pharmacological treatments without evidence for unwanted side effects. The functional consequences of rescue were prominent with regard to memory but also extended to self-organization of behavior. SIGNIFICANCE STATEMENT Brain aging is characterized by a progressive loss of dendritic arbors and the emergence of impairments to learning-related synaptic plasticity. The present studies show that dendritic losses are evident by middle age despite housing in an enriched environment and can be

  3. Protracted dendritic growth in the typically developing human amygdala and increased spine density in young ASD brains.

    Science.gov (United States)

    Weir, R K; Bauman, M D; Jacobs, B; Schumann, C M

    2018-02-01

    The amygdala is a medial temporal lobe structure implicated in social and emotional regulation. In typical development (TD), the amygdala continues to increase volumetrically throughout childhood and into adulthood, while other brain structures are stable or decreasing in volume. In autism spectrum disorder (ASD), the amygdala undergoes rapid early growth, making it volumetrically larger in children with ASD compared to TD children. Here we explore: (a) if dendritic arborization in the amygdala follows the pattern of protracted growth in TD and early overgrowth in ASD and (b), if spine density in the amygdala in ASD cases differs from TD from youth to adulthood. The amygdala from 32 postmortem human brains (7-46 years of age) were stained using a Golgi-Kopsch impregnation. Ten principal neurons per case were selected in the lateral nucleus and traced using Neurolucida software in their entirety. We found that both ASD and TD individuals show a similar pattern of increasing dendritic length with age well into adulthood. However, spine density is (a) greater in young ASD cases compared to age-matched TD controls (ASD age into adulthood, a phenomenon not found in TD. Therefore, by adulthood, there is no observable difference in spine density in the amygdala between ASD and TD age-matched adults (≥18 years old). Our findings highlight the unique growth trajectory of the amygdala and suggest that spine density may contribute to aberrant development and function of the amygdala in children with ASD. © 2017 Wiley Periodicals, Inc.

  4. High-Yield Synthesis of Janus Dendritic Mesoporous Silica@Resorcinol-Formaldehyde Nanoparticles: A Competing Growth Mechanism.

    Science.gov (United States)

    Qu, Lili; Hu, Huicheng; Yu, Jiaqi; Yu, Xiaoya; Liu, Jian; Xu, Yong; Zhang, Qiao

    2017-05-30

    Recently, Janus nanostructures that possess two or more different surface functions have attracted enormous attention because of their unique structures and promising applications in diverse fields. In this work, we present that Janus structured dendritic mesoporous silica@resorcinol-formaldehyde (DMS@RF) nanoparticles can be prepared through a simple one-pot colloidal method. The Janus DMS@RF nanoparticle shows a bonsai-like morphology which consists of a dendritic mesoporous silica part and a spherical RF part. After a systematic study on the growth process, we proposed a competing growth mechanism that accounts for the formation of Janus nanostructures. It is believed that suitable polymerization rate of silica and RF resin is critical. Based on the competing growth mechanism, eccentric and concentric core-shell nanostructures have been successfully prepared by tuning the polymerization rates of silica and RF, respectively. Metal-contained ternary Janus nanoparticles that might be used for catalysis have also been prepared. This research may pave the way for the practical applications of delicate nanomaterials with desired structures and properties.

  5. Degenerate seaweed to tilted dendrite transition and their growth dynamics in directional solidification of non-axially oriented crystals: a phase-field study

    Science.gov (United States)

    Xing, Hui; Dong, Xianglei; Wu, Hongjing; Hao, Guanhua; Wang, Jianyuan; Chen, Changle; Jin, Kexin

    2016-05-01

    We report the results of a phase-field study of degenerate seaweed to tilted dendrite transition and their growth dynamics during directional solidification of a binary alloy. Morphological selection maps in the planes of (G, Vp) and (ε4, Vp) show that lower pulling velocity, weaker anisotropic strength and higher thermal gradient can enhance the formation of the degenerate seaweed. The tip undercooling shows oscillations in seaweed growth, but it keeps at a constant value in dendritic growth. The M-S instability on the tips and the surface tension anisotropy of the solid-liquid interface are responsible for the formation of the degenerate seaweed. It is evidenced that the place where the interfacial instability occurs determines the morphological transition. The transient transition from degenerate seaweed to tilted dendrite shows that dendrites are dynamically preferred over seaweed. For the tilted dendritic arrays with a large tilted angle, primary spacing is investigated by comparing predicted results with the classical scaling power law, and the growth direction is found to be less sensitive to the pulling velocity and the primary spacing. Furthermore, the effect of the initial interface wavelength on the morphological transition is investigated to perform the history dependence of morphological selection.

  6. Dendritic design as an archetype for growth patterns in Nature: fractal and constructal views

    Directory of Open Access Journals (Sweden)

    Antonio F. Miguel

    2014-02-01

    Full Text Available The occurrence of configuration (design, shape, structure, rhythm is a universal phenomenon that occurs in every flow system. Dendritic configuration (or tree-shaped configurations is ubiquitous in nature and likely to arise in both animate and inanimate flow systems. Why is it so important? Is there a principle from which this configuration can be deduced? In this review paper we show that these systems own two of the most important properties of fractals that are self-similarity and scaling. Their configuration do not develop by chance. It´s occurrence is a universal phenomenon of physics covered by a principle. Here we also show that the emergence of dendritic configuration in flow systems constitutes a basic supportive flow path along which order need to persist is propagated.

  7. RAB-10 Regulates Dendritic Branching by Balancing Dendritic Transport

    Science.gov (United States)

    Taylor, Caitlin A.; Yan, Jing; Howell, Audrey S.; Dong, Xintong; Shen, Kang

    2015-01-01

    The construction of a large dendritic arbor requires robust growth and the precise delivery of membrane and protein cargoes to specific subcellular regions of the developing dendrite. How the microtubule-based vesicular trafficking and sorting systems are regulated to distribute these dendritic development factors throughout the dendrite is not well understood. Here we identify the small GTPase RAB-10 and the exocyst complex as critical regulators of dendrite morphogenesis and patterning in the C. elegans sensory neuron PVD. In rab-10 mutants, PVD dendritic branches are reduced in the posterior region of the cell but are excessive in the distal anterior region of the cell. We also demonstrate that the dendritic branch distribution within PVD depends on the balance between the molecular motors kinesin-1/UNC-116 and dynein, and we propose that RAB-10 regulates dendrite morphology by balancing the activity of these motors to appropriately distribute branching factors, including the transmembrane receptor DMA-1. PMID:26633194

  8. Does facial resemblance enhance cooperation?

    Directory of Open Access Journals (Sweden)

    Trang Giang

    Full Text Available Facial self-resemblance has been proposed to serve as a kinship cue that facilitates cooperation between kin. In the present study, facial resemblance was manipulated by morphing stimulus faces with the participants' own faces or control faces (resulting in self-resemblant or other-resemblant composite faces. A norming study showed that the perceived degree of kinship was higher for the participants and the self-resemblant composite faces than for actual first-degree relatives. Effects of facial self-resemblance on trust and cooperation were tested in a paradigm that has proven to be sensitive to facial trustworthiness, facial likability, and facial expression. First, participants played a cooperation game in which the composite faces were shown. Then, likability ratings were assessed. In a source memory test, participants were required to identify old and new faces, and were asked to remember whether the faces belonged to cooperators or cheaters in the cooperation game. Old-new recognition was enhanced for self-resemblant faces in comparison to other-resemblant faces. However, facial self-resemblance had no effects on the degree of cooperation in the cooperation game, on the emotional evaluation of the faces as reflected in the likability judgments, and on the expectation that a face belonged to a cooperator rather than to a cheater. Therefore, the present results are clearly inconsistent with the assumption of an evolved kin recognition module built into the human face recognition system.

  9. In-situ study of the dendritic growth in lithium/polymer electrolyte-salt/lithium cells; Etude in-situ de la croissance dendritique dans des cellules lithium/POE-sel/lithium

    Energy Technology Data Exchange (ETDEWEB)

    Brissot, C.; Rosso, M.; Chazalviel, J.N. [Ecole Polytechnique, 91 - Palaiseau (France); Baudry, P.; Lascaud, S. [Electricite de France, 77 - Moret sur Loing (France). Direction des Etudes et Recherches

    1996-12-31

    The in-situ observation of dendritic growth in lithium/polymer electrolyte-LiTFSI/lithium battery cells shows that dendrites grow up with about the same rate as anion migration. Memory effects have been evidenced in cycling experiments and limit the dendrites length. An overall movement of the electrolyte due to variations of electrolyte concentration in the vicinity of the electrodes has been observed too. (J.S.) 13 refs.

  10. A single amino acid substitution is sufficient to modify the mitogenic properties of the epidermal growth factor receptor to resemble that of gp185erbB-2

    DEFF Research Database (Denmark)

    Di Fiore, P P; Helin, K; Kraus, M H

    1992-01-01

    The epidermal growth factor (EGF) receptor (EGFR) and the erbB-2 gene product, gp185erbB-2, exhibit distinct abilities to stimulate mitogenesis in different target cells. By using chimeric molecules between these two receptors, we have previously shown that their intracellular juxtamembrane regio...

  11. Developmental hypothyroxinaemia and hypothyroidism limit dendritic growth of cerebellar Purkinje cells in rat offspring: involvement of microtubule-associated protein 2 (MAP2) and stathmin.

    Science.gov (United States)

    Wang, Yuan; Wang, Yi; Dong, Jing; Wei, Wei; Song, Binbin; Min, Hui; Teng, Weiping; Chen, Jie

    2014-06-01

    Iodine is essential for the synthesis of thyroid hormone. Iodine deficiency (ID)-induced hypothyroxinaemia and hypothyroidism during developmental period contribute to impairments of function in the brain, such as psychomotor and motor alterations. However, the mechanisms are still unclear. Therefore, the present research is to study the effects of developmental hypothyroxinaemia caused by mild ID and developmental hypothyroidism caused by severe ID or methimazole (MMZ) on dendritic growth in filial cerebellar Purkinje cells (PCs) and the underlying mechanisms. A maternal hypothyroxinaemia model was established in Wistar rats using a mild ID diet, and two maternal hypothyroidism models were developed with either severe ID diet or MMZ water. We examined the total dendritic length using immunofluorescence, and Western blot analysis was conducted to investigate the activity of microtubule-associated protein 2 (MAP2), stathmin and calcium/calmodulin-dependent protein kinase II (CaMKII). Hypothyroxinaemia and hypothyroidism reduced the total dendritic length of cerebellar PCs, decreased MAP2 and its phosphorylation, increased stathmin but reduced its phosphorylation and down-regulated the activity of CaMKII and its phosphorylation in cerebellar PCs on postnatal day (PN) 7, PN14 and PN21. Developmental hypothyroxinaemia induced by mild ID and hypothyroidism induced by severe ID or MMZ limit PCs dendritic growth, which may involve in the disturbance of MAP2 and stathmin in a CaMKII-dependent manner. It suggests a potential mechanism of motor coordination impairments caused by developmental hypothyroxinaemia and hypothyroidism. © 2013 British Neuropathological Society.

  12. An inverse approach for elucidating dendritic function

    Directory of Open Access Journals (Sweden)

    Benjamin Torben-Nielsen

    2010-09-01

    Full Text Available We outline an inverse approach for investigating dendritic function-structure relationships by optimizing dendritic trees for a-priori chosen computational functions. The inverse approach can be applied in two different ways. First, we can use it as a `hypothesis generator' in which we optimize dendrites for a function of general interest. The optimization yields an artificial dendrite that is subsequently compared to real neurons. This comparison potentially allows us to propose hypotheses about the function of real neurons. In this way, we investigated dendrites that optimally perform input-order detection. Second, we can use it as a `function confirmation' by optimizing dendrites for functions hypothesized to be performed by classes of neurons. If the optimized, artificial, dendrites resemble the dendrites of real neurons the artificial dendrites corroborate the hypothesized function of the real neuron. Moreover, properties of the artificial dendrites can lead to predictions about yet unmeasured properties. In this way, we investigated wide-field motion integration performed by the VS cells of the fly visual system. In outlining the inverse approach and two applications, we also elaborate on the nature of dendritic function. We furthermore discuss the role of optimality in assigning functions to dendrites and point out interesting future directions.

  13. Histamine Promotes the Development of Monocyte-Derived Dendritic Cells and Reduces Tumor Growth by Targeting the Myeloid NADPH Oxidase

    Science.gov (United States)

    Wiktorin, Hanna G.; Lenox, Brianna; Ewald Sander, Frida; Aydin, Ebru; Aurelius, Johan; Thorén, Fredrik B.; Ståhlberg, Anders; Hermodsson, Svante; Hellstrand, Kristoffer

    2015-01-01

    The efficiency of immune-mediated clearance of cancer cells is hampered by immunosuppressive mediators in the malignant microenvironment, including NADPH oxidase–derived reactive oxygen species. We aimed at defining the effects of histamine, an inhibitor of the myeloid NADPH oxidase/NOX2, on the development of Ag-presenting dendritic cells (DCs) from myeloid precursors and the impact of these mechanisms for tumor growth. Histamine was found to promote the maturation of human DCs from monocytes by increasing the expression of HLA-DR and costimulatory molecules, which resulted in improved induction of Th cells with Th0 polarity. Experiments using wild-type and NOX2-deficient myelomonoblastic cells showed that histamine facilitated myeloid cell maturation only in cells capable of generating reactive oxygen species. Treatment of mice with histamine reduced the growth of murine EL-4 lymphomas in parallel with an increment of tumor-infiltrating DCs in NOX2-sufficient mice but not in NOX2-deficient (gp91phox−/−) mice. We propose that strategies to target the myeloid NADPH oxidase may facilitate the development of endogenous DCs in cancer. PMID:25870245

  14. TGF-β Signaling in Dopaminergic Neurons Regulates Dendritic Growth, Excitatory-Inhibitory Synaptic Balance, and Reversal Learning

    Directory of Open Access Journals (Sweden)

    Sarah X. Luo

    2016-12-01

    Full Text Available Neural circuits involving midbrain dopaminergic (DA neurons regulate reward and goal-directed behaviors. Although local GABAergic input is known to modulate DA circuits, the mechanism that controls excitatory/inhibitory synaptic balance in DA neurons remains unclear. Here, we show that DA neurons use autocrine transforming growth factor β (TGF-β signaling to promote the growth of axons and dendrites. Surprisingly, removing TGF-β type II receptor in DA neurons also disrupts the balance in TGF-β1 expression in DA neurons and neighboring GABAergic neurons, which increases inhibitory input, reduces excitatory synaptic input, and alters phasic firing patterns in DA neurons. Mice lacking TGF-β signaling in DA neurons are hyperactive and exhibit inflexibility in relinquishing learned behaviors and re-establishing new stimulus-reward associations. These results support a role for TGF-β in regulating the delicate balance of excitatory/inhibitory synaptic input in local microcircuits involving DA and GABAergic neurons and its potential contributions to neuropsychiatric disorders.

  15. Phase-field modelling of β(Ti) solidification in Ti-45at.%Al: columnar dendrite growth at various gravity levels

    Science.gov (United States)

    Viardin, A.; Berger, R.; Sturz, L.; Apel, M.; Hecht, U.

    2016-03-01

    The effect of solutal convection on the solidification of γ titanium aluminides, specifically on β(Ti) dendrite growth, is not well known. With the aim of supporting directional solidification experiments under hyper-gravity using a large diameter centrifuge, 2D-phase field simulations of β(Ti) dendrite growth have been performed for the binary alloy Ti-45at.%Al and various gravity scenarios. Both, the direction and magnitude of the gravity vector were varied systematically in order to reveal the subtle interplay between the convective flow pattern and mushy zone characteristics. In this presentation, gravity effects are discussed for early dendrite growth. For selected cases the evolution on longer timescales is also analyse of and oscillatory modes leading to dynamically stable steady state growth are outlined. In a dedicated simulation series forced flow is superimposed, as to mimic thermally driven fluid flow expected to establish on the macroscopic scale (sample size) in the centrifugal experiments. Above a certain threshold this flow turns dominant and precludes solutally driven convective effects.

  16. Antibacterial compounds of Canadian honeys target bacterial cell wall inducing phenotype changes, growth inhibition and cell lysis that resemble action of β-lactam antibiotics.

    Science.gov (United States)

    Brudzynski, Katrina; Sjaarda, Calvin

    2014-01-01

    Honeys show a desirable broad spectrum activity against Gram-positive and negative bacteria making antibacterial activity an intrinsic property of honey and a desirable source for new drug development. The cellular targets and underlying mechanism of action of honey antibacterial compounds remain largely unknown. To facilitate the target discovery, we employed a method of phenotypic profiling by directly comparing morphological changes in Escherichia coli induced by honeys to that of ampicillin, the cell wall-active β-lactam of known mechanism of action. Firstly, we demonstrated the purity of tested honeys from potential β-lactam contaminations using quantitative LC-ESI-MS. Exposure of log-phase E. coli to honey or ampicillin resulted in time- and concentration-dependent changes in bacterial cell shape with the appearance of filamentous phenotypes at sub-inhibitory concentrations and spheroplasts at the MBC. Cell wall destruction by both agents, clearly visible on microscopic micrographs, was accompanied by increased permeability of the lipopolysaccharide outer membrane as indicated by fluorescence-activated cell sorting (FACS). More than 90% E. coli exposed to honey or ampicillin became permeable to propidium iodide. Consistently with the FACS results, both honey-treated and ampicillin-treated E. coli cells released lipopolysaccharide endotoxins at comparable levels, which were significantly higher than controls (ptransformed with the ampicillin-resistance gene (β-lactamase) remained sensitive to honey, displayed the same level of cytotoxicity, cell shape changes and endotoxin release as ampicillin-sensitive cells. As expected, β-lactamase protected the host cell from antibacterial action of ampicillin. Thus, both honey and ampicillin induced similar structural changes to the cell wall and LPS and that this ability underlies antibacterial activities of both agents. Since the cell wall is critical for cell growth and survival, honey active compounds would be

  17. Antibacterial compounds of Canadian honeys target bacterial cell wall inducing phenotype changes, growth inhibition and cell lysis that resemble action of β-lactam antibiotics.

    Directory of Open Access Journals (Sweden)

    Katrina Brudzynski

    Full Text Available Honeys show a desirable broad spectrum activity against Gram-positive and negative bacteria making antibacterial activity an intrinsic property of honey and a desirable source for new drug development. The cellular targets and underlying mechanism of action of honey antibacterial compounds remain largely unknown. To facilitate the target discovery, we employed a method of phenotypic profiling by directly comparing morphological changes in Escherichia coli induced by honeys to that of ampicillin, the cell wall-active β-lactam of known mechanism of action. Firstly, we demonstrated the purity of tested honeys from potential β-lactam contaminations using quantitative LC-ESI-MS. Exposure of log-phase E. coli to honey or ampicillin resulted in time- and concentration-dependent changes in bacterial cell shape with the appearance of filamentous phenotypes at sub-inhibitory concentrations and spheroplasts at the MBC. Cell wall destruction by both agents, clearly visible on microscopic micrographs, was accompanied by increased permeability of the lipopolysaccharide outer membrane as indicated by fluorescence-activated cell sorting (FACS. More than 90% E. coli exposed to honey or ampicillin became permeable to propidium iodide. Consistently with the FACS results, both honey-treated and ampicillin-treated E. coli cells released lipopolysaccharide endotoxins at comparable levels, which were significantly higher than controls (p<0.0001. E. coli cells transformed with the ampicillin-resistance gene (β-lactamase remained sensitive to honey, displayed the same level of cytotoxicity, cell shape changes and endotoxin release as ampicillin-sensitive cells. As expected, β-lactamase protected the host cell from antibacterial action of ampicillin. Thus, both honey and ampicillin induced similar structural changes to the cell wall and LPS and that this ability underlies antibacterial activities of both agents. Since the cell wall is critical for cell growth and

  18. Growth differentiation factor-15 suppresses maturation and function of dendritic cells and inhibits tumor-specific immune response.

    Directory of Open Access Journals (Sweden)

    Zhizhong Zhou

    Full Text Available Dendritic cells (DCs play a key role in the initiation stage of an antigen-specific immune response. A variety of tumor-derived factors (TDFs can suppress DC maturation and function, resulting in defects in the tumor-specific immune response. To identify unknown TDFs that may suppress DCs maturation and function, we established a high-throughput screening technology based on a human liver tumor T7 phage cDNA library and screened all of the proteins derived from hepatoma cells that potentially interact with immature DCs. Growth/differentiation factor-15 (GDF-15 was detected and chosen for further study. By incubation of DCs cultures with GDF-15, we demonstrate that GDF-15 can inhibit surface protrusion formation during DC maturation; suppress the membrane expression of CD83, CD86 and HLA-DR on DCs; enhance phagocytosis by DCs; reduce IL-12 and elevate TGF-β1 secretion by DCs; inhibit T cell stimulation and cytotoxic T lymphocyte (CTL activation by DCs. By building tumor-bearing mouse models, we demonstrate that GDF-15 can inhibit the ability of DCs to stimulate a tumor-specific immune response in vivo. These results indicate that GDF-15 may be one of the critical molecules that inhibit DC maturation and function and are involved in tumor immune escape. Thus, GDF-15 may be a novel target in tumor immunotherapy.

  19. Biophysical Properties and Motility of Human Mature Dendritic Cells Deteriorated by Vascular Endothelial Growth Factor through Cytoskeleton Remodeling

    Directory of Open Access Journals (Sweden)

    Zu-Quan Hu

    2016-10-01

    Full Text Available Dendritic cells (DCs, the most potent antigen-presenting cells, play a central role in the initiation, regulation, and maintenance of the immune responses. Vascular endothelial growth factor (VEGF is one of the important cytokines in the tumor microenvironment (TME and can inhibit the differentiation and functional maturation of DCs. To elucidate the potential mechanisms of DC dysfunction induced by VEGF, the effects of VEGF on the biophysical characteristics and motility of human mature DCs (mDCs were investigated. The results showed that VEGF had a negative influence on the biophysical properties, including electrophoretic mobility, osmotic fragility, viscoelasticity, and transmigration. Further cytoskeleton structure analysis by confocal microscope and gene expression profile analyses by gene microarray and real-time PCR indicated that the abnormal remodeling of F-actin cytoskeleton may be the main reason for the deterioration of biophysical properties, motility, and stimulatory capability of VEGF-treated mDCs. This is significant for understanding the biological behavior of DCs and the immune escape mechanism of tumors. Simultaneously, the therapeutic efficacies may be improved by blocking the signaling pathway of VEGF in an appropriate manner before the deployment of DC-based vaccinations against tumors.

  20. Growth kinetics of NaCl crystals in a drying drop of gelatin: transition from faceted to dendritic growth

    Science.gov (United States)

    Dutta Choudhury, Moutushi; Dutta, Tapati; Tarafdar, Sujata

    We report a study on the kinetics of drying of a droplet of aqueous gelatin containing sodium chloride. The process of drying recorded on video, clearly shows different regimes of growth leading to a variety of crystalline patterns. Large faceted crystals of $\\sim$mm size form in the early stages of evaporation, followed by highly branched multi-fractal patterns with micron sized features. We simulate the growth using a simple algorithm incorporating aggregation and evaporation, which reproduces the cross-over between the two growth regimes. As evaporation proceeds, voids form in the gel film. The time development of the fluid-void system can be characterized by an Euler number. A minimum in the Euler number marks the transition between the two regimes of growth.

  1. Deletion of the NMDA receptor GluN2A subunit significantly decreases dendritic growth in maturing dentate granule neurons.

    Directory of Open Access Journals (Sweden)

    Timal S Kannangara

    Full Text Available It is known that NMDA receptors can modulate adult hippocampal neurogenesis, but the contribution of specific regulatory GluN2 subunits has been difficult to determine. Here we demonstrate that mice lacking GluN2A (formerly NR2A do not show altered cell proliferation or neuronal differentiation, but present significant changes in neuronal morphology in dentate granule cells. Specifically, GluN2A deletion significantly decreased total dendritic length and dendritic complexity in DG neurons located in the inner granular zone. Furthermore, the absence of GluN2A also resulted in a localized increase in spine density in the middle molecular layer, a region innervated by the medial perforant path. Interestingly, alterations in dendritic morphology and spine density were never seen in dentate granule cells located in the outer granular zone, a region that has been hypothesized to contain older, more mature, neurons. These results indicate that although the GluN2A subunit is not critical for the cell proliferation and differentiation stages of the neurogenic process, it does appear to play a role in establishing synaptic and dendritic morphology in maturing dentate granule cells localized in the inner granular zone.

  2. Treatment of transplanted CT26 tumour with dendritic cell vaccine in combination with blockade of vascular endothelial growth factor receptor 2 and CTLA-4

    DEFF Research Database (Denmark)

    Pedersen, Anders Elm; Buus, S; Claesson, M H

    2005-01-01

    We investigated the anti CT26 tumour effect of dendritic cell based vaccination with the MuLV gp70 envelope protein-derived peptides AH1 and p320-333. Vaccination lead to generation of AH1 specific cytotoxic lymphocytes (CTL) and some decrease in tumour growth of simultaneously inoculated CT26...... of mice with already established tumours was only obtained after combination of vaccination, DC101 and 9H10 treatment in which setting 80% of the mice rejected their tumours....

  3. A cellular automaton - finite volume method for the simulation of dendritic and eutectic growth in binary alloys using an adaptive mesh refinement

    Science.gov (United States)

    Dobravec, Tadej; Mavrič, Boštjan; Šarler, Božidar

    2017-11-01

    A two-dimensional model to simulate the dendritic and eutectic growth in binary alloys is developed. A cellular automaton method is adopted to track the movement of the solid-liquid interface. The diffusion equation is solved in the solid and liquid phases by using an explicit finite volume method. The computational domain is divided into square cells that can be hierarchically refined or coarsened using an adaptive mesh based on the quadtree algorithm. Such a mesh refines the regions of the domain near the solid-liquid interface, where the highest concentration gradients are observed. In the regions where the lowest concentration gradients are observed the cells are coarsened. The originality of the work is in the novel, adaptive approach to the efficient and accurate solution of the posed multiscale problem. The model is verified and assessed by comparison with the analytical results of the Lipton-Glicksman-Kurz model for the steady growth of a dendrite tip and the Jackson-Hunt model for regular eutectic growth. Several examples of typical microstructures are simulated and the features of the method as well as further developments are discussed.

  4. Recrystallization phenomena of solution grown paraffin dendrites

    NARCIS (Netherlands)

    Hollander, F.F.A.; Hollander, F.; Stasse, O.; van Suchtelen, J.; van Enckevort, W.J.P.

    2001-01-01

    Paraffin crystals were grown from decane solutions using a micro-Bridgman set up for in-situ observation of the morphology at the growth front. It is shown that for large imposed velocities, dendrites are obtained. After dendritic growth, aging or recrystallization processes set in rather quickly,

  5. Dendritic cells modified by vitamin D

    DEFF Research Database (Denmark)

    Pedersen, Ayako Wakatsuki; Claesson, Mogens Helweg; Zocca, Mai-Britt

    2011-01-01

    Dendritic cells (DCs), the most potent antigen-presenting cells of the immune system, express nuclear receptors for 1,25-dihydroxyvitamin D(3) (VD3) and they are one of its main targets. In the presence of VD3, DCs differentiate into a phenotype that resembles semimature DCs, with reduced T cell...

  6. Dendritic cells pulsed with tumor cells killed by high hydrostatic pressure inhibit prostate tumor growth in TRAMP mice

    Czech Academy of Sciences Publication Activity Database

    Mikyšková, Romana; Indrová, Marie; Štěpánek, Ivan; Kanchev, Ivan; Bieblová, Jana; Vošahlíková, Š.; Moserová, I.; Truxová, I.; Fučíková, J.; Bartunkova, J.; Spisek, R.; Sedláček, Radislav; Reiniš, Milan

    2017-01-01

    Roč. 6, č. 12 (2017), č. článku e1362528. ISSN 2162-402X R&D Projects: GA MŠk(CZ) LM2015040; GA MŠk(CZ) ED1.1.00/02.0109; GA MŠk ED2.1.00/19.0395; GA ČR GA15-24769S Institutional support: RVO:68378050 Keywords : dendritic cells * docetaxel * high hydrostatic pressure * immunotherapy * prostate cancer Subject RIV: EB - Genetics ; Molecular Biology OBOR OECD: Immunology Impact factor: 7.719, year: 2016

  7. Dendritic outgrowth of myenteric plexus neurons in primary culture.

    Science.gov (United States)

    Mulholland, M W; Romanchuk, G; Flowe, K

    1992-04-01

    Myenteric plexus neurons derived from neonatal guinea pigs, when exposed to serum, demonstrated a characteristic pattern of growth, including a proliferating outgrowth zone of glial cells, peripheral extension of dendritic processes, and progressive dendritic growth. Serum effects upon dendritic growth, measured morphometrically, was strongly dose- and temporally dependent. Dendritic density was increased 10-fold (120 hr) by the addition of 6% serum, while mean dendritic length was increased 3-fold. Development of cholinergic function was reflected by release of [3H]ACh in response to cholecystokinin octapeptide, vasoactive intestinal peptide, substance P, and calcitonin gene-related peptide (10(-10) and 10(-8) M).

  8. Facile fabrication of dendritic silver structures and their surface ...

    Indian Academy of Sciences (India)

    A simple and efficient approach was developed to fabricate silver dendrites by Cu reducing Ag+ in AgNO3 solution. The growth speed, morphologies and structures of the silver dendrites strongly depend on AgNO3 concentration and reaction time. The silver dendrites were formed from nanosheets and the crystal structure ...

  9. Monocyte-derived dendritic cells from patients with dermatophytosis restrict the growth of Trichophyton rubrum and induce CD4-T cell activation.

    Directory of Open Access Journals (Sweden)

    Karla Santiago

    Full Text Available Dermatophytes are the most common agents of superficial mycoses that are caused by mold fungi. Trichophyton rubrum is the most common pathogen causing dermatophytosis. The immunology of dermatophytosis is currently poorly understood. Recently, our group investigated the interaction of T. rubrum conidia with peritoneal mouse macrophages. We found that macrophages phagocytose T. rubrum conidia resulted in a down-modulation of class II major histocompatibility complex (MHC antigens and in the expression of co-stimulatory molecules. Furthermore, it induced the production of IL-10, and T. rubrum conidia differentiated into hyphae that grew and killed the macrophages after 8 hrs of culture. This work demonstrated that dendritic cells (DCs and macrophages, from patients or normal individuals, avidly interact with pathogenic fungus T. rubrum. The dermatophyte has two major receptors on human monocyte-derived DC: DC-SIGN and mannose receptor. In contrast macrophage has only mannose receptor that participates in the phagocytosis or bound process. Another striking aspect of this study is that unlike macrophages that permit rapid growth of T. rubrum, human DC inhibited the growth and induces Th activation. The ability of DC from patients to interact and kill T. rubrum and to present Ags to T cells suggests that DC may play an important role in the host response to T. rubrum infection by coordinating the development of cellular immune response.

  10. Models for growth, decline and regrowth of the dendrites of rat Purkinje cells induced from magnitude and link-length analysis.

    Science.gov (United States)

    Woldenberg, M J; O'Neill, M P; Quackenbush, L J; Pentney, R J

    1993-06-21

    This study examines Purkinje neurons of rats aged 1, 10, 18 and 28 months to investigate growth and decline in the magnitude of the dendritic tree, i.e. the number of exterior links (terminal segments) per cell. Growth in the mean number of exterior links was observed from 1 to 10 months, decline at 18 months and regrowth at 28 months. At 10, 28, and especially at 18 months, the cell size frequency distribution indicates two groups of cells, one of small and the other of large sized cells. The study also examines the relationship of age to lengths of topologically defined links of various types. For each age group we find that exterior links are longer than interior links (non-terminal or intermediate segments). Analysis of the geometric mean lengths of subtypes of exterior and interior links at maturity (10 months) indicates that they follow a Fibonacci series of link lengths, such that mean lengths of topologically defined types of mean exterior links are either about 13 or 8 microns long, while interior links are about 5 microns long. A sequential growth model for adding exterior links is suggested to illustrate a style of growth which could account for the various mean link lengths and the Fibonacci ratio (1.618) between their lengths. Interior link lengths are also dependent on the generation of exterior links from the sides of pre-existing interior links. If the Strahler branching ratio, Rb, should increase owing to growth of terminals from interior links, then mean interior link length would decline. During a period of regression, mean exterior link lengths become shorter and mean interior link lengths become longer. Changes in mean interior link length are much less affected by changes in Rb during regression than is the situation during growth. Finally, the changes in link lengths dictate that the ratio of mean exterior to mean interior link length increases during growth phases from 1 to 10 and 18 to 28 months, and declines during regression from 10 to 28

  11. From atomistic interfaces to dendritic patterns

    Science.gov (United States)

    Galenko, P. K.; Alexandrov, D. V.

    2018-01-01

    Transport processes around phase interfaces, together with thermodynamic properties and kinetic phenomena, control the formation of dendritic patterns. Using the thermodynamic and kinetic data of phase interfaces obtained on the atomic scale, one can analyse the formation of a single dendrite and the growth of a dendritic ensemble. This is the result of recent progress in theoretical methods and computational algorithms calculated using powerful computer clusters. Great benefits can be attained from the development of micro-, meso- and macro-levels of analysis when investigating the dynamics of interfaces, interpreting experimental data and designing the macrostructure of samples. The review and research articles in this theme issue cover the spectrum of scales (from nano- to macro-length scales) in order to exhibit recently developing trends in the theoretical analysis and computational modelling of dendrite pattern formation. Atomistic modelling, the flow effect on interface dynamics, the transition from diffusion-limited to thermally controlled growth existing at a considerable driving force, two-phase (mushy) layer formation, the growth of eutectic dendrites, the formation of a secondary dendritic network due to coalescence, computational methods, including boundary integral and phase-field methods, and experimental tests for theoretical models-all these themes are highlighted in the present issue. This article is part of the theme issue `From atomistic interfaces to dendritic patterns'.

  12. Transforming growth factor beta-activated kinase 1 (TAK1)-dependent checkpoint in the survival of dendritic cells promotes immune homeostasis and function.

    Science.gov (United States)

    Wang, Yanyan; Huang, Gonghua; Vogel, Peter; Neale, Geoffrey; Reizis, Boris; Chi, Hongbo

    2012-02-07

    Homeostatic control of dendritic cell (DC) survival is crucial for adaptive immunity, but the molecular mechanism is not well defined. Moreover, how DCs influence immune homeostasis under steady state remains unclear. Combining DC-specific and -inducible deletion systems, we report that transforming growth factor beta-activated kinase 1 (TAK1) is an essential regulator of DC survival and immune system homeostasis and function. Deficiency of TAK1 in CD11c(+) cells induced markedly elevated apoptosis, leading to the depletion of DC populations, especially the CD8(+) and CD103(+) DC subsets in lymphoid and nonlymphoid tissues, respectively. TAK1 also contributed to DC development by promoting the generation of DC precursors. Prosurvival signals from Toll-like receptors, CD40 and receptor activator of nuclear factor-κB (RANK) are integrated by TAK1 in DCs, which in turn mediated activation of downstream NF-κB and AKT-Foxo pathways and established a gene-expression program. TAK1 deficiency in DCs caused a myeloid proliferative disorder characterized by expansion of neutrophils and inflammatory monocytes, disrupted T-cell homeostasis, and prevented effective T-cell priming and generation of regulatory T cells. Moreover, TAK1 signaling in DCs was required to prevent myeloid proliferation even in the absence of lymphocytes, indicating a previously unappreciated regulatory mechanism of DC-mediated control of myeloid cell-dependent inflammation. Therefore, TAK1 orchestrates a prosurvival checkpoint in DCs that affects the homeostasis and function of the immune system.

  13. Randomly oriented twin domains in electrodeposited silver dendrites

    Directory of Open Access Journals (Sweden)

    Ivanović Evica R.

    2015-01-01

    Full Text Available Silver dendrites were prepared by electrochemical deposition. The structures of Ag dendrites, the type of twins and their distribution were investigated by scanning electron microscopy (SEM, Z-contrast high angle annular dark field transmission electron microscopy (HAADF, and crystallografically sensitive orientation imaging microscopy (OIM. The results revealed that silver dendrites are characterized by the presence of randomly distributed 180° rotational twin domains. The broad surface of dendrites was of the {111} type. Growth directions of the main dendrite stem and all branches were of type. [Projekat Ministarstva nauke Republike Srbije, br. 172054

  14. Breast cancer vaccines delivered by dendritic cell-targeted lentivectors induce potent antitumor immune responses and protect mice from mammary tumor growth.

    Science.gov (United States)

    Bryson, Paul D; Han, Xiaolu; Truong, Norman; Wang, Pin

    2017-10-13

    Breast cancer immunotherapy is a potent treatment option, with antibody therapies such as trastuzumab increasing 2-year survival rates by 50%. However, active immunotherapy through vaccination has generally been clinically ineffective. One potential means of improving vaccine therapy is by delivering breast cancer antigens to dendritic cells (DCs) for enhanced antigen presentation. To accomplish this in vivo, we pseudotyped lentiviral vector (LV) vaccines with a modified Sindbis Virus glycoprotein so that they could deliver genes encoding the breast cancer antigen alpha-lactalbumin (Lalba) or erb-b2 receptor tyrosine kinase 2 (ERBB2 or HER2) directly to resident DCs. We hypothesized that utilizing these DC-targeting lentiviral vectors asa breast cancer vaccine could lead to an improved immune response against self-antigens found in breast cancer tumors. Indeed, single injections of the vaccine vectors were able to amplify antigen-specific CD8T cells 4-6-fold over naïve mice, similar to the best published vaccine regimens. Immunization of these mice completely inhibited tumor growth in a foreign antigen environment (LV-ERBB2 in wildtype mice), and it reduced the rate of tumor growth in a self-antigen environment (LV-Lalba in wildtype or LV-ERBB2 in MMTV-huHER2 transgenic). These results show that a single injection with targeted lentiviral vectors can be an effective immunotherapy for breast cancer. Furthermore, they could be combined with other immunotherapeutic regimens to improve outcomes for patients with breast cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Antigen-presenting dendritic cells as regulators of the growth of thyrocytes: a role of interleukin-1beta and interleukin-6

    NARCIS (Netherlands)

    P.J. Simons (Peter); F.G. Delemarre; H.A. Drexhage (Hemmo)

    1998-01-01

    textabstractAn accumulation of antigen-presenting dendritic cells (DC) in the thyroid gland, followed by thyroid autoimmune reactivity, occurs in normal Wistar rats during iodine deficiency, and spontaneously in diabetic-prone Biobreeding rats. This intrathyroidal DC

  16. RAB-10-Dependent Membrane Transport Is Required for Dendrite Arborization

    Science.gov (United States)

    Zou, Wei; Yadav, Smita; DeVault, Laura; Jan, Yuh Nung; Sherwood, David R.

    2015-01-01

    Formation of elaborately branched dendrites is necessary for the proper input and connectivity of many sensory neurons. Previous studies have revealed that dendritic growth relies heavily on ER-to-Golgi transport, Golgi outposts and endocytic recycling. How new membrane and associated cargo is delivered from the secretory and endosomal compartments to sites of active dendritic growth, however, remains unknown. Using a candidate-based genetic screen in C. elegans, we have identified the small GTPase RAB-10 as a key regulator of membrane trafficking during dendrite morphogenesis. Loss of rab-10 severely reduced proximal dendritic arborization in the multi-dendritic PVD neuron. RAB-10 acts cell-autonomously in the PVD neuron and localizes to the Golgi and early endosomes. Loss of function mutations of the exocyst complex components exoc-8 and sec-8, which regulate tethering, docking and fusion of transport vesicles at the plasma membrane, also caused proximal dendritic arborization defects and led to the accumulation of intracellular RAB-10 vesicles. In rab-10 and exoc-8 mutants, the trans-membrane proteins DMA-1 and HPO-30, which promote PVD dendrite stabilization and branching, no longer localized strongly to the proximal dendritic membranes and instead were sequestered within intracellular vesicles. Together these results suggest a crucial role for the Rab10 GTPase and the exocyst complex in controlling membrane transport from the secretory and/or endosomal compartments that is required for dendritic growth. PMID:26394140

  17. Resemblances in the Wedding and Natal Customs

    OpenAIRE

    Reneta Zlateva; Zlatozhivka Zdravkova

    2011-01-01

    The present article describes the natal rites and customs of the Azerbaijan and Bulgarian nations. Special attention is paid to the resemblances in the practicing and understanding of the traditions. Despite the fact that the two nations live in regions remote from each other, they have common beliefs and strive to provide prosperity for the home, family and children.

  18. On the resemblance of synapse formation and CNS myelination.

    Science.gov (United States)

    Almeida, R G; Lyons, D A

    2014-09-12

    The myelination of axons in the central nervous system (CNS) is essential for nervous system formation, function and health. CNS myelination continues well into adulthood, but not all axons become myelinated. Unlike the peripheral nervous system, where we know of numerous axon-glial signals required for myelination, we have a poor understanding of the nature or identity of such molecules that regulate which axons are myelinated in the CNS. Recent studies have started to elucidate cell behavior during myelination in vivo and indicate that the choice of which axons are myelinated is made prior to myelin sheath generation. Here we propose that interactions between axons and the exploratory processes of oligodendrocyte precursor cells (OPCs) lead to myelination and may be similar to those between dendrites and axons that prefigure and lead to synapse formation. Indeed axons and OPCs form synapses with striking resemblance to those of neurons, suggesting a similar mode of formation. We discuss families of molecules with specific functions at different stages of synapse formation and address studies that implicate the same factors during axon-OPC synapse formation and myelination. We also address the possibility that the function of such synapses might directly regulate the myelinating behavior of oligodendrocyte processes in vivo. In the future it may be of benefit to consider these similarities when taking a candidate-based approach to dissect mechanisms of CNS myelination. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

  19. The effect of fluid flow due to the crystal-melt density change on the growth of a parabolic isothermal dendrite

    Science.gov (United States)

    Mcfadden, G. B.; Coriell, S. R.

    1986-01-01

    The Ivantsov (1947) analysis of an isolated isothermal dendrite (with zero surface tension) growing into a supercooled liquid is extended to include the effects of the fluid flow due to volume contraction or expansion upon solidification. For an axisymmetric paraboloidal dendrite, an analytic solution to the Navier-Stokes equations is obtained. The magnitude of the flow is proportional to the relative density change epsilon, and the flow becomes negligible far from the surface of the dendrite. The temperature field consistent with this flow can also be found explicitly. The well-known expression that relates the dimensionless supercooling to the Peclet number in the absence of fluid flow is modified for nonzero epsilon, but the effect is of order epsilon and hence is seen to be minor for most values of epsilon and dimensionless supercooling that occur in practice.

  20. Social perception of facial resemblance in humans.

    Science.gov (United States)

    DeBruine, Lisa M; Jones, Benedict C; Little, Anthony C; Perrett, David I

    2008-02-01

    Two lines of reasoning predict that highly social species will have mechanisms to influence behavior toward individuals depending on their degree of relatedness. First, inclusive fitness theory leads to the prediction that organisms will preferentially help closely related kin over more distantly related individuals. Second, evaluation of the relative costs and potential benefits of inbreeding suggests that the degree of kinship should also be considered when choosing a mate. In order to behaviorally discriminate between individuals with different levels of relatedness, organisms must be able to discriminate cues of kinship. Facial resemblance is one such potential cue in humans. Computer-graphic manipulation of face images has made it possible to experimentally test hypotheses about human kin recognition by facial phenotype matching. We review recent experimental evidence that humans respond to facial resemblance in ways consistent with inclusive fitness theory and considerations of the costs of inbreeding, namely by increasing prosocial behavior and positive attributions toward self-resembling images and selectively tempering attributions of attractiveness to other-sex faces in the context of a sexual relationship.

  1. Dendritic cell vaccines.

    Science.gov (United States)

    Mosca, Paul J; Lyerly, H Kim; Clay, Timothy M; Morse, Michael A; Lyerly, H Kim

    2007-05-01

    Dendritic cells are antigen-presenting cells that have been shown to stimulate tumor antigen-specific T cell responses in preclinical studies. Consequently, there has been intense interest in developing dendritic cell based cancer vaccines. A variety of methods for generating dendritic cells, loading them with tumor antigens, and administering them to patients have been described. In recent years, a number of early phase clinical trials have been performed and have demonstrated the safety and feasibility of dendritic cell immunotherapies. A number of these trials have generated valuable preliminary data regarding the clinical and immunologic response to DC-based immunotherapy. The emphasis of dendritic cell immunotherapy research is increasingly shifting toward the development of strategies to increase the potency of dendritic cell vaccine preparations.

  2. Excess of nerve growth factor in the ovary causes a polycystic ovary-like syndrome in mice, which closely resembles both reproductive and metabolic aspects of the human syndrome.

    Science.gov (United States)

    Wilson, Jenny L; Chen, Weiyi; Dissen, Gregory A; Ojeda, Sergio R; Cowley, Michael A; Garcia-Rudaz, Cecilia; Enriori, Pablo J

    2014-11-01

    Polycystic ovarian syndrome (PCOS), the most common female endocrine disorder of unknown etiology, is characterized by reproductive abnormalities and associated metabolic conditions comprising insulin resistance, type 2 diabetes mellitus, and dyslipidemia. We previously reported that transgenic overexpression of nerve growth factor (NGF), a marker of sympathetic hyperactivity, directed to the ovary by the mouse 17α-hydroxylase/C17-20 lyase promoter (17NF mice), results in ovarian abnormalities similar to those seen in PCOS women. To investigate whether ovarian overproduction of NGF also induces common metabolic alterations of PCOS, we assessed glucose homeostasis by glucose tolerance test, plasma insulin levels, and body composition by dual-energy x-ray absorptiometry scan in young female 17NF mice and wild-type mice. 17NF mice exhibited increased body weight and alterations in body fat distribution with a greater accumulation of visceral fat compared with sc fat (P ovary may suffice to cause both reproductive and metabolic alterations characteristic of PCOS and support the hypothesis that sympathetic hyperactivity may contribute to the development and/or progression of PCOS.

  3. Surface energy-driven growth of crystalline PbS octahedra and dendrites in the presence of cyclodextrin–surfactant supramolecular complexes

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Pradip, E-mail: pkgangwar84@gmail.com; Kim, Whi Dong; Lee, Seokwon; Lee, Dennis T. [Korea Advanced Institute of Science and Technology (KAIST), Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury (Korea, Republic of); Lee, Kangtaek [Yonsei University, Department of Chemical and Biomolecular Engineering (Korea, Republic of); Lee, Doh C., E-mail: dclee@kaist.edu [Korea Advanced Institute of Science and Technology (KAIST), Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury (Korea, Republic of)

    2015-02-15

    PbS crystals of cubic, octahedral, and dendritic shapes are synthesized in an aqueous solution that contains supramolecular complexes of β-cyclodextrin (CD) and hexadecyltrimethylammonium bromide (CTAB). The morphology of the PbS crystals depends on the concentration of CD or CTAB in the reaction solution; for example, the branched dendritic structures evolve with an appropriate molar ratio of CD/CTAB supramolecular complexes and reaction time. Regardless of the CD/CTAB molar ratios, octahedral PbS crystals are observed at all compositions of CD/CTAB for the reaction times of 1–5 h, while self-assembled branched/dendritic structures are obtained only for CD/CTAB molar ratios of 0.5, 1, and 2 after a prolonged reaction, e.g., for 24–48 h. Systematic investigation reveals that both reaction time and CD/CTAB molar ratio are responsible for self-assembled branched/dendritic structures of octahedral crystals.

  4. Dendritic thickness: a morphometric parameter to classify mouse retinal ganglion cells

    Directory of Open Access Journals (Sweden)

    L.D. Loopuijt

    2007-10-01

    Full Text Available To study the dendritic morphology of retinal ganglion cells in wild-type mice we intracellularly injected these cells with Lucifer yellow in an in vitro preparation of the retina. Subsequently, quantified values of dendritic thickness, number of branching points and level of stratification of 73 Lucifer yellow-filled ganglion cells were analyzed by statistical methods, resulting in a classification into 9 groups. The variables dendritic thickness, number of branching points per cell and level of stratification were independent of each other. Number of branching points and level of stratification were independent of eccentricity, whereas dendritic thickness was positively dependent (r = 0.37 on it. The frequency distribution of dendritic thickness tended to be multimodal, indicating the presence of at least two cell populations composed of neurons with dendritic diameters either smaller or larger than 1.8 µm ("thin" or "thick" dendrites, respectively. Three cells (4.5% were bistratified, having thick dendrites, and the others (95.5% were monostratified. Using k-means cluster analysis, monostratified cells with either thin or thick dendrites were further subdivided according to level of stratification and number of branching points: cells with thin dendrites were divided into 2 groups with outer stratification (0-40% and 2 groups with inner (50-100% stratification, whereas cells with thick dendrites were divided into one group with outer and 3 groups with inner stratification. We postulate, that one group of cells with thin dendrites resembles cat ß-cells, whereas one group of cells with thick dendrites includes cells that resemble cat a-cells.

  5. Multiple ureterolithiasis resembling steinstrasse: An unusual presentation

    Directory of Open Access Journals (Sweden)

    Praveen Kumar Pandey

    2014-12-01

    Full Text Available Steinstrasse or “stone street” is an expected complication after extracorporeal shock wave lithotripsy in patients with high stone burden. However, there are published reports of multiple ureterolithiasis resembling steinstrasse in patients with distal renal tubular acidosis. Here we report an uncommon case of a 60-year-old woman who presented with right renal calculi. Her right ureter was studded with multiple calculi up to the vesicoureteric junction. The affected right kidney was nonfunctional and was managed by nephroureterectomy.

  6. Facile fabrication of dendritic silver structures and their surface ...

    Indian Academy of Sciences (India)

    in AgNO3 solution. The growth speed, morphologies and structures of the silver dendrites strongly depend on AgNO3 concentration and reaction time. The silver dendrites were formed from nanosheets and the crystal structure is face-centered cubic. Rhodamine 6G was used as probe molecule to show that the silver ...

  7. Body elimination attitude family resemblance in Kuwait.

    Science.gov (United States)

    Al-Fayez, Ghenaim; Awadalla, Abdelwahid; Arikawa, Hiroko; Templer, Donald I; Hutton, Shane

    2009-12-01

    The purpose of the present study was to determine the family resemblance of attitude toward body elimination in Kuwaiti participants. This study was conceptualized in the context of the theories of moral development, importance of cleanliness in the Muslim religion, cross-cultural differences in personal hygiene practices, previous research reporting an association between family attitudes and body elimination attitude, and health implications. The 24-item Likert-type format Body Elimination Attitude Scale-Revised was administered to 277 Kuwaiti high school students and 437 of their parents. Females scored higher, indicating greater disgust, than the males. Moreover, sons' body elimination attitude correlated more strongly with fathers' attitude (r = .85) than with that of the mothers (r = .64). Daughters' attitude was similarly associated with the fathers' (r = .89) and the mothers' attitude (r = .86). The high correlations were discussed within the context of Kuwait having a collectivistic culture with authoritarian parenting style. The higher adolescent correlations, and in particular the boys' correlation with fathers than with mothers, was explained in terms of the more dominant role of the Muslim father in the family. Public health and future research implications were suggested. A theoretical formulation was advanced in which "ideal" body elimination attitude is relative rather than absolute, and is a function of one's life circumstances, one's occupation, one's culture and subculture, and the society that one lives in.

  8. Spiny Neurons of Amygdala, Striatum and Cortex Use Dendritic Plateau Potentials to Detect Network UP States

    Directory of Open Access Journals (Sweden)

    Katerina D Oikonomou

    2014-09-01

    Full Text Available Spiny neurons of amygdala, striatum, and cerebral cortex share four interesting features: [1] they are the most abundant cell type within their respective brain area, [2] covered by thousands of thorny protrusions (dendritic spines, [3] possess high levels of dendritic NMDA conductances, and [4] experience sustained somatic depolarizations in vivo and in vitro (UP states. In all spiny neurons of the forebrain, adequate glutamatergic inputs generate dendritic plateau potentials (dendritic UP states characterized by (i fast rise, (ii plateau phase lasting several hundred milliseconds and (iii abrupt decline at the end of the plateau phase. The dendritic plateau potential propagates towards the cell body decrementally to induce a long-lasting (longer than 100 ms, most often 200 – 800 ms steady depolarization (~20 mV amplitude, which resembles a neuronal UP state. Based on voltage-sensitive dye imaging, the plateau depolarization in the soma is precisely time-locked to the regenerative plateau potential taking place in the dendrite. The somatic plateau rises after the onset of the dendritic voltage transient and collapses with the breakdown of the dendritic plateau depolarization. We hypothesize that neuronal UP states in vivo reflect the occurrence of dendritic plateau potentials (dendritic UP states. We propose that the somatic voltage waveform during a neuronal UP state is determined by dendritic plateau potentials. A mammalian spiny neuron uses dendritic plateau potentials to detect and transform coherent network activity into a ubiquitous neuronal UP state. The biophysical properties of dendritic plateau potentials allow neurons to quickly attune to the ongoing network activity, as well as secure the stable amplitudes of successive UP states.

  9. Dendritic cell neoplasms: an overview.

    Science.gov (United States)

    Kairouz, Sebastien; Hashash, Jana; Kabbara, Wadih; McHayleh, Wassim; Tabbara, Imad A

    2007-10-01

    Dendritic cell neoplasms are rare tumors that are being recognized with increasing frequency. They were previously classified as lymphomas, sarcomas, or histiocytic neoplasms. The World Health Organization (WHO) classifies dendritic cell neoplasms into five groups: Langerhans' cell histiocytosis, Langerhans' cell sarcoma, Interdigitating dendritic cell sarcoma/tumor, Follicular dendritic cell sarcoma/tumor, and Dendritic cell sarcoma, not specified otherwise (Jaffe, World Health Organization classification of tumors 2001; 273-289). Recently, Pileri et al. provided a comprehensive immunohistochemical classification of histiocytic and dendritic cell tumors (Pileri et al., Histopathology 2002;59:161-167). In this article, a concise overview regarding the pathological, clinical, and therapeutic aspects of follicular dendritic, interdigitating dendritic, and Langerhans' cell tumors is presented.

  10. Modification of dendritic development.

    Science.gov (United States)

    Feria-Velasco, Alfredo; del Angel, Alma Rosa; Gonzalez-Burgos, Ignacio

    2002-01-01

    Since 1890 Ramón y Cajal strongly defended the theory that dendrites and their processes and spines had a function of not just nutrient transport to the cell body, but they had an important conductive role in neural impulse transmission. He extensively discussed and supported this theory in the Volume 1 of his extraordinary book Textura del Sistema Nervioso del Hombre y de los Vertebrados. Also, Don Santiago significantly contributed to a detailed description of the various neural components of the hippocampus and cerebral cortex during development. Extensive investigation has been done in the last Century related to the functional role of these complex brain regions, and their association with learning, memory and some limbic functions. Likewise, the organization and expression of neuropsychological qualities such as memory, exploratory behavior and spatial orientation, among others, depend on the integrity and adequate functional activity of the cerebral cortex and hippocampus. It is known that brain serotonin synthesis and release depend directly and proportionally on the availability of its precursor, tryptophan (TRY). By using a chronic TRY restriction model in rats, we studied their place learning ability in correlation with the dendritic spine density of pyramidal neurons in field CA1 of the hippocampus during postnatal development. We have also reported alterations in the maturation pattern of the ability for spontaneous alternation and task performance evaluating short-term memory, as well as adverse effects on the density of dendritic spines of hippocampal CA1 field pyramidal neurons and on the dendritic arborization and the number of dendritic spines of pyramidal neurons from the third layer of the prefrontal cortex using the same model of TRY restriction. The findings obtained in these studies employing a modified Golgi method, can be interpreted as a trans-synaptic plastic response due to understimulation of serotoninergic receptors located in the

  11. Dendritic maturation in cat retinal ganglion cells: a Lucifer yellow study.

    Science.gov (United States)

    Dann, J F; Buhl, E H; Peichl, L

    1987-09-11

    The dendritic morphology of developing cat alpha- and beta-retinal ganglion cells was investigated by intracellular injection of Lucifer yellow. In both cell classes the basic pattern of adult morphology was present at birth. However, the presence of transient small spiny protrusions along the dendrites was characteristic of early postnatal cells. Many alpha-cells were further distinguished by a small degree of dendritic bi-stratification which disappeared within the first 5 postnatal days. Therefore during the period before the eyes opened (P7-P10) there was a considerable degree of modification and maturation in dendritic morphology in both classes of retinal ganglion cells. alpha- and beta-cells exhibited differing temporal patterns of dendritic growth, which argues against a 'passive-stretching' hypothesis that explains dendritic field enlargement solely as an effect of retinal areal growth.

  12. Parental Investment and Resemblance: Replications, Refinements, and Revisions

    Directory of Open Access Journals (Sweden)

    Anthony A. Volk

    2007-01-01

    Full Text Available Evolutionary theory predicts that men should be more concerned with issues of false paternity than women should be concerned with false maternity. In an earlier study (Volk and Quinsey, 2002, we studied how infant cues of resemblance influenced adults' hypothetical adoption decisions. We found that self-perceived cues of resemblance were significantly more important in men's decisions than in women's. Since that study was published, conflicting results have been reported regarding a sex-difference in the importance of cues of resemblance for adoption preference. We therefore sought to replicate our findings in three new studies. In all three studies, we replicated the initial finding of a larger correlation between ratings of resemblance and ratings of adoption preference among men than among women. We also found a trend towards slightly higher global resemblance scores in younger children, suggesting that adults view infants as more anonymous and/or less uniquely distinctive than older children. However, there was wide variance in both the global resemblance and developmental changes in resemblance amongst the different child stimuli used.

  13. Magnetic and dendritic catalysts.

    Science.gov (United States)

    Wang, Dong; Deraedt, Christophe; Ruiz, Jaime; Astruc, Didier

    2015-07-21

    The recovery and reuse of catalysts is a major challenge in the development of sustainable chemical processes. Two methods at the frontier between homogeneous and heterogeneous catalysis have recently emerged for addressing this problem: loading the catalyst onto a dendrimer or onto a magnetic nanoparticle. In this Account, we describe representative examples of these two methods, primarily from our research group, and compare them. We then describe new chemistry that combines the benefits of these two methods of catalysis. Classic dendritic catalysis has involved either attaching the catalyst covalently at the branch termini or within the dendrimer core. We have used chelating pyridyltriazole ligands to insolubilize catalysts at the termini of dendrimers, providing an efficient, recyclable heterogeneous catalysts. With the addition of dendritic unimolecular micelles olefin metathesis reactions catalyzed by commercial Grubbs-type ruthenium-benzylidene complexes in water required unusually low amounts of catalyst. When such dendritic micelles include intradendritic ligands, both the micellar effect and ligand acceleration promote faster catalysis in water. With these types of catalysts, we could carry out azide alkyne cycloaddition ("click") chemistry with only ppm amounts of CuSO4·5H2O and sodium ascorbate under ambient conditions. Alternatively we can attach catalysts to the surface of superparamagnetic iron oxide nanoparticles (SPIONs), essentially magnetite (Fe3O4) or maghemite (γ-Fe2O3), offering the opportunity to recover the catalysts using magnets. Taking advantage of the merits of both of these strategies, we and others have developed a new generation of recyclable catalysts: dendritic magnetically recoverable catalysts. In particular, some of our catalysts with a γ-Fe2O3@SiO2 core and 1,2,3-triazole tethers and loaded with Pd nanoparticles generate strong positive dendritic effects with respect to ligand loading, catalyst loading, catalytic activity and

  14. Core-Shell-structured Dendritic Mesoporous Silica Nanoparticles for Combined Photodynamic Therapy and Antibody Delivery.

    Science.gov (United States)

    Abbaraju, Prasanna Lakshmi; Yang, Yannan; Yu, Meihua; Fu, Jianye; Xu, Chun; Yu, Chengzhong

    2017-07-04

    Multifunctional core-shell-structured dendritic mesoporous silica nanoparticles with a fullerene-doped silica core, a dendritic silica shell and large pores have been prepared. The combination of photodynamic therapy and antibody therapeutics significantly inhibits the cancer cell growth by effectively reducing the level of anti-apoptotic proteins. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. The correlation between dendritic microstructure and mechanical properties of directionally solidified hypoeutectic Al-Ni alloys

    Science.gov (United States)

    Canté, Manuel V.; Spinelli, José E.; Cheung, Noé; Garcia, Amauri

    2010-02-01

    Al-Ni hypoeutectic alloys were directionally solidified under upward transient heat flow conditions. The aim of the present study is to set up correlations between the as-cast microstructure and the resulting mechanical properties of these alloys. The dependence of primary and secondary dendrite arm spacing on the alloy solute content and on solidification thermal parameters is also analyzed. The results include transient metal/mold heat transfer coefficient, tip growth rate, cooling rate, dendrite arm spacing, ultimate tensile strength, yield tensile strength and elongation. Expressions relating dendrite spacing to solidification thermal parameters and mechanical properties to the scale of the dendritic microstructure have been determined. It was found that the ultimate tensile strength and the yield tensile strength increase with increasing alloy solute content and with decreasing primary and secondary dendrite arm spacing. In contrast, the elongation was found to be independent of both alloy composition and dendritic arrangement.

  16. The unfolded protein response is required for dendrite morphogenesis

    Science.gov (United States)

    Wei, Xing; Howell, Audrey S; Dong, Xintong; Taylor, Caitlin A; Cooper, Roshni C; Zhang, Jianqi; Zou, Wei; Sherwood, David R; Shen, Kang

    2015-01-01

    Precise patterning of dendritic fields is essential for the formation and function of neuronal circuits. During development, dendrites acquire their morphology by exuberant branching. How neurons cope with the increased load of protein production required for this rapid growth is poorly understood. Here we show that the physiological unfolded protein response (UPR) is induced in the highly branched Caenorhabditis elegans sensory neuron PVD during dendrite morphogenesis. Perturbation of the IRE1 arm of the UPR pathway causes loss of dendritic branches, a phenotype that can be rescued by overexpression of the ER chaperone HSP-4 (a homolog of mammalian BiP/ grp78). Surprisingly, a single transmembrane leucine-rich repeat protein, DMA-1, plays a major role in the induction of the UPR and the dendritic phenotype in the UPR mutants. These findings reveal a significant role for the physiological UPR in the maintenance of ER homeostasis during morphogenesis of large dendritic arbors. DOI: http://dx.doi.org/10.7554/eLife.06963.001 PMID:26052671

  17. Dendrite Injury Triggers DLK-Independent Regeneration

    Directory of Open Access Journals (Sweden)

    Michelle C. Stone

    2014-01-01

    Full Text Available Axon injury triggers regeneration through activation of a conserved kinase cascade, which includes the dual leucine zipper kinase (DLK. Although dendrites are damaged during stroke, traumatic brain injury, and seizure, it is not known whether mature neurons monitor dendrite injury and initiate regeneration. We probed the response to dendrite damage using model Drosophila neurons. Two larval neuron types regrew dendrites in distinct ways after all dendrites were removed. Dendrite regeneration was also triggered by injury in adults. Next, we tested whether dendrite injury was initiated with the same machinery as axon injury. Surprisingly, DLK, JNK, and fos were dispensable for dendrite regeneration. Moreover, this MAP kinase pathway was not activated by injury to dendrites. Thus, neurons respond to dendrite damage and initiate regeneration without using the conserved DLK cascade that triggers axon regeneration.

  18. Macrophages as APC and the dendritic cell myth.

    Science.gov (United States)

    Hume, David A

    2008-11-01

    Dendritic cells have been considered an immune cell type that is specialized for the presentation of Ag to naive T cells. Considerable effort has been applied to separate their lineage, pathways of differentiation, and effectiveness in Ag presentation from those of macrophages. This review summarizes evidence that dendritic cells are a part of the mononuclear phagocyte system and are derived from a common precursor, responsive to the same growth factors (including CSF-1), express the same surface markers (including CD11c), and have no unique adaptation for Ag presentation that is not shared by other macrophages.

  19. Spousal resemblance in psychopathology: A comparison of parents of children with and without psychopathology

    NARCIS (Netherlands)

    Wesseldijk, L. W.; Dieleman, G. C.; Lindauer, R. J. L.; Bartels, M.; Willemsen, G.; Hudziak, J. J.; Boomsma, D. I.; Middeldorp, C. M.

    2016-01-01

    Spouses resemble each other for psychopathology, but data regarding spousal resemblance in externalizing psychopathology, and data regarding spousal resemblance across different syndromes (e.g. anxiety in wives and attention deficit/hyperactivity disorder [ADHD] in husbands) are limited. Moreover,

  20. A Model of Dendritic Cell Therapy for Melanoma

    Directory of Open Access Journals (Sweden)

    Ami eRadunskaya

    2013-03-01

    Full Text Available Dendritic cells are a promising immunotherapy tool for boosting an individual's antigen specific immune response to cancer. We develop a mathematical model using differential and delay-differential equations to describe the interactions between dendritic cells, effector-immune cells and tumor cells. We account for the trafficking of immune cells between lymph, blood, and tumor compartments. Our model reflects experimental results both for dendritic-cell trafficking and for immune suppression of tumor growth in mice. In addition, in silico experiments suggest more effective immunotherapy treatment protocols can be achieved by modifying dose location and schedule. A sensitivity analysis of the model reveals which patient-specific parameters have the greatest impact on treatment efficacy.

  1. RESEMBLANCE OF INDIRECTNESS IN POLITENESS OF EFL LEARNERS’ REQUEST REALIZATIONS

    Directory of Open Access Journals (Sweden)

    Indawan Syahri

    2013-07-01

    Full Text Available Abstract: Politeness principles are universally utilized by the speakers of any language when realizing various speech acts. However, the speakers of particular languages relatively apply politeness due to the cultural norms embedded. The present study attempts to delineate how the Indonesian learners of English (ILE apply the politeness principles in request realizations. Specifically it devotes to the types of politeness strategies applied and resemblance of the indirectness in politeness strategies in requesting acts. The FTAs and indirectness are the theoretical bases used to trace the typologies of both politeness and request strategies. The data werere collected by means of certain elicitation techniques, i.e. DCTs and Role-plays. The analyses werere done through three stages; determining request strategies, politeness strategies, and resemblance of indirectness in politeness. The results show that the indirectness generally is parallel to politeness. Besides, some pragmatic transfers are found in terms of applying native-culture norms in realizing target speech acts.

  2. Homophilic Protocadherin Cell-Cell Interactions Promote Dendrite Complexity

    Directory of Open Access Journals (Sweden)

    Michael J. Molumby

    2016-05-01

    Full Text Available Growth of a properly complex dendrite arbor is a key step in neuronal differentiation and a prerequisite for neural circuit formation. Diverse cell surface molecules, such as the clustered protocadherins (Pcdhs, have long been proposed to regulate circuit formation through specific cell-cell interactions. Here, using transgenic and conditional knockout mice to manipulate γ-Pcdh repertoire in the cerebral cortex, we show that the complexity of a neuron’s dendritic arbor is determined by homophilic interactions with other cells. Neurons expressing only one of the 22 γ-Pcdhs can exhibit either exuberant or minimal dendrite complexity, depending only on whether surrounding cells express the same isoform. Furthermore, loss of astrocytic γ-Pcdhs, or disruption of astrocyte-neuron homophilic matching, reduces dendrite complexity cell non-autonomously. Our data indicate that γ-Pcdhs act locally to promote dendrite arborization via homophilic matching, and they confirm that connectivity in vivo depends on molecular interactions between neurons and between neurons and astrocytes.

  3. Allergic Contact Dermatitis to Benzoyl Peroxide Resembling Impetigo.

    Science.gov (United States)

    Kim, Changhyun; Craiglow, Brittany G; Watsky, Kalman L; Antaya, Richard J

    2015-01-01

    A 17-year-old boy presented with recurring severe dermatitis of the face of 5-months duration that resembled impetigo. He had been treated with several courses of antibiotics without improvement. Biopsy showed changes consistent with allergic contact dermatitis and patch testing later revealed sensitization to benzoyl peroxide, which the patient had been using for the treatment of acne vulgaris. © 2015 Wiley Periodicals, Inc.

  4. Native valve endocarditis caused by an organism resembling Corynebacterium striatum.

    OpenAIRE

    Markowitz, S M; Coudron, P E

    1990-01-01

    An organism resembling Corynebacterium striatum was isolated from the blood of a patient with acute aortic valvular insufficiency and no history of valvular heart disease. At autopsy, histopathologic examination of the aortic valve revealed pleomorphic gram-positive bacilli and destruction of valvular tissue. Our isolate differed from other nondiphtherial corynebacteria, including the type strain of C. striatum (ATCC 6940), in its ability to reduce nitrite. Nitrite reduction may be useful for...

  5. Detecting analogical resemblance without retrieving the source analogy.

    Science.gov (United States)

    Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

    2010-06-01

    We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory.

  6. Dendritic Homeostasis Disruption in a Novel Frontotemporal Dementia Mouse Model Expressing Cytoplasmic Fused in Sarcoma

    Directory of Open Access Journals (Sweden)

    Gen Shiihashi

    2017-10-01

    Full Text Available Cytoplasmic aggregation of fused in sarcoma (FUS is detected in brain regions affected by amyotrophic lateral sclerosis (ALS and frontotemporal dementia (FTD, which compose the disease spectrum, FUS proteinopathy. To understand the pathomechanism of ALS-FTD-associated FUS, we examined the behavior and cellular properties of an ALS mouse model overexpressing FUS with nuclear localization signal deletion. Mutant FUS transgenic mice showed hyperactivity, social interactional deficits, and impaired fear memory retrieval, all of which are compatible with FTD phenotypes. Histological analyses showed decreased dendritic spine and synaptic density in the frontal cortex before neuronal loss. Examination of cultured cells confirmed that mutant but not wild-type FUS was associated with decreased dendritic growth, mRNA levels, and protein synthesis in dendrites. These data suggest that cytoplasmic FUS aggregates impair dendritic mRNA trafficking and translation, in turn leading to dendritic homeostasis disruption and the development of FTD phenotypes.

  7. Turtle functions downstream of Cut in differentially regulating class specific dendrite morphogenesis in Drosophila.

    Directory of Open Access Journals (Sweden)

    Mikolaj J Sulkowski

    Full Text Available Dendritic morphology largely determines patterns of synaptic connectivity and electrochemical properties of a neuron. Neurons display a myriad diversity of dendritic geometries which serve as a basis for functional classification. Several types of molecules have recently been identified which regulate dendrite morphology by acting at the levels of transcriptional regulation, direct interactions with the cytoskeleton and organelles, and cell surface interactions. Although there has been substantial progress in understanding the molecular mechanisms of dendrite morphogenesis, the specification of class-specific dendritic arbors remains largely unexplained. Furthermore, the presence of numerous regulators suggests that they must work in concert. However, presently, few genetic pathways regulating dendrite development have been defined.The Drosophila gene turtle belongs to an evolutionarily conserved class of immunoglobulin superfamily members found in the nervous systems of diverse organisms. We demonstrate that Turtle is differentially expressed in Drosophila da neurons. Moreover, MARCM analyses reveal Turtle acts cell autonomously to exert class specific effects on dendritic growth and/or branching in da neuron subclasses. Using transgenic overexpression of different Turtle isoforms, we find context-dependent, isoform-specific effects on mediating dendritic branching in class II, III and IV da neurons. Finally, we demonstrate via chromatin immunoprecipitation, qPCR, and immunohistochemistry analyses that Turtle expression is positively regulated by the Cut homeodomain transcription factor and via genetic interaction studies that Turtle is downstream effector of Cut-mediated regulation of da neuron dendrite morphology.Our findings reveal that Turtle proteins differentially regulate the acquisition of class-specific dendrite morphologies. In addition, we have established a transcriptional regulatory interaction between Cut and Turtle, representing

  8. Resemblance operations and conceptual complexity in animal metaphors

    Directory of Open Access Journals (Sweden)

    Aneider Iza Ervitia

    2012-07-01

    Full Text Available For over thirty years cognitive linguists have devoted much effort to the study of metaphors based on the correlation of events in human experience to the detriment of the more traditional notion of resemblance metaphor, which exploits perceived similarities among objects. Grady (1999 draws attention to this problem and calls for a more serious study of the latter type of metaphor. The present paper takes up this challenge on the basis of a small corpus of ‘animal’ metaphors in English, which are essentially based on resemblance. Contrary to previous analyses by cognitive linguists (e.g. Lakoff & Turner 1989, Ruiz de Mendoza Ibáñez, 1998, who claim that such metaphors are based on a single mapping generally involving comparable behavioral attributes, I will argue that we have a more complex situation which involves different patterns of conceptual interaction. In this respect, I have identified cases of (i animal metaphors interacting with high-level (i.e. grammatical metaphors and metonymies, of (ii (situational animal metaphors whose source domains are constructed metonymically (cf. Goossens 1990; Ruiz de Mendoza Ibáñez & Díez Velasco 2002, and of (iii animal metaphors interacting with other metaphors thereby giving rise to metaphoric amalgams (cf. Ruiz de Mendoza Ibáñez & Galera Masegosa 2011.

  9. Primary Dendrite Array Morphology: Observations from Ground-based and Space Station Processed Samples

    Science.gov (United States)

    Tewari, Surendra; Rajamure, Ravi; Grugel, Richard; Erdmann, Robert; Poirier, David

    2012-01-01

    Influence of natural convection on primary dendrite array morphology during directional solidification is being investigated under a collaborative European Space Agency-NASA joint research program, "Microstructure Formation in Castings of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions (MICAST)". Two Aluminum-7 wt pct Silicon alloy samples, MICAST6 and MICAST7, were directionally solidified in microgravity on the International Space Station. Terrestrially grown dendritic monocrystal cylindrical samples were remelted and directionally solidified at 18 K/cm (MICAST6) and 28 K/cm (MICAST7). Directional solidification involved a growth speed step increase (MICAST6-from 5 to 50 micron/s) and a speed decrease (MICAST7-from 20 to 10 micron/s). Distribution and morphology of primary dendrites is currently being characterized in these samples, and also in samples solidified on earth under nominally similar thermal gradients and growth speeds. Primary dendrite spacing and trunk diameter measurements from this investigation will be presented.

  10. Tumour tissue microenvironment can inhibit dendritic cell maturation in colorectal cancer.

    LENUS (Irish Health Repository)

    Michielsen, Adriana J

    2011-01-01

    Inflammatory mediators in the tumour microenvironment promote tumour growth, vascular development and enable evasion of anti-tumour immune responses, by disabling infiltrating dendritic cells. However, the constituents of the tumour microenvironment that directly influence dendritic cell maturation and function are not well characterised. Our aim was to identify tumour-associated inflammatory mediators which influence the function of dendritic cells. Tumour conditioned media obtained from cultured colorectal tumour explant tissue contained high levels of the chemokines CCL2, CXCL1, CXCL5 in addition to VEGF. Pre-treatment of monocyte derived dendritic cells with this tumour conditioned media inhibited the up-regulation of CD86, CD83, CD54 and HLA-DR in response to LPS, enhancing IL-10 while reducing IL-12p70 secretion. We examined if specific individual components of the tumour conditioned media (CCL2, CXCL1, CXCL5) could modulate dendritic cell maturation or cytokine secretion in response to LPS. VEGF was also assessed as it has a suppressive effect on dendritic cell maturation. Pre-treatment of immature dendritic cells with VEGF inhibited LPS induced upregulation of CD80 and CD54, while CXCL1 inhibited HLA-DR. Interestingly, treatment of dendritic cells with CCL2, CXCL1, CXCL5 or VEGF significantly suppressed their ability to secrete IL-12p70 in response to LPS. In addition, dendritic cells treated with a combination of CXCL1 and VEGF secreted less IL-12p70 in response to LPS compared to pre-treatment with either cytokine alone. In conclusion, tumour conditioned media strongly influences dendritic cell maturation and function.

  11. Tumour tissue microenvironment can inhibit dendritic cell maturation in colorectal cancer.

    Directory of Open Access Journals (Sweden)

    Adriana J Michielsen

    Full Text Available Inflammatory mediators in the tumour microenvironment promote tumour growth, vascular development and enable evasion of anti-tumour immune responses, by disabling infiltrating dendritic cells. However, the constituents of the tumour microenvironment that directly influence dendritic cell maturation and function are not well characterised. Our aim was to identify tumour-associated inflammatory mediators which influence the function of dendritic cells. Tumour conditioned media obtained from cultured colorectal tumour explant tissue contained high levels of the chemokines CCL2, CXCL1, CXCL5 in addition to VEGF. Pre-treatment of monocyte derived dendritic cells with this tumour conditioned media inhibited the up-regulation of CD86, CD83, CD54 and HLA-DR in response to LPS, enhancing IL-10 while reducing IL-12p70 secretion. We examined if specific individual components of the tumour conditioned media (CCL2, CXCL1, CXCL5 could modulate dendritic cell maturation or cytokine secretion in response to LPS. VEGF was also assessed as it has a suppressive effect on dendritic cell maturation. Pre-treatment of immature dendritic cells with VEGF inhibited LPS induced upregulation of CD80 and CD54, while CXCL1 inhibited HLA-DR. Interestingly, treatment of dendritic cells with CCL2, CXCL1, CXCL5 or VEGF significantly suppressed their ability to secrete IL-12p70 in response to LPS. In addition, dendritic cells treated with a combination of CXCL1 and VEGF secreted less IL-12p70 in response to LPS compared to pre-treatment with either cytokine alone. In conclusion, tumour conditioned media strongly influences dendritic cell maturation and function.

  12. Modeling of Dendritic Evolution of Continuously Cast Steel Billet with Cellular Automaton

    Science.gov (United States)

    Wang, Weiling; Ji, Cheng; Luo, Sen; Zhu, Miaoyong

    2018-02-01

    In order to predict the dendritic evolution during the continuous steel casting process, a simple mechanism to connect the heat transfer at the macroscopic scale and the dendritic growth at the microscopic scale was proposed in the present work. As the core of the across-scale simulation, a two-dimensional cell automaton (CA) model with a decentered square algorithm was developed and parallelized. Apart from nucleation undercooling and probability, a temperature gradient was introduced to deal with the columnar-to-equiaxed transition (CET) by considering its variation during continuous casting. Based on the thermal history, the dendritic evolution in a 4 mm × 40 mm region near the centerline of a SWRH82B steel billet was predicted. The influences of the secondary cooling intensity, superheat, and casting speed on the dendritic structure of the billet were investigated in detail. The results show that the predicted equiaxed dendritic solidification of Fe-5.3Si alloy and columnar dendritic solidification of Fe-0.45C alloy are consistent with in situ experimental results [Yasuda et al. Int J Cast Metals Res 22:15-21 (2009); Yasuda et al. ISIJ Int 51:402-408 (2011)]. Moreover, the predicted dendritic arm spacing and CET location agree well with the actual results in the billet. The primary dendrite arm spacing of columnar dendrites decreases with increasing secondary cooling intensity, or decreasing superheat and casting speed. Meanwhile, the CET is promoted as the secondary cooling intensity and superheat decrease. However, the CET is not influenced by the casting speed, owing to the adjusting of the flow rate of secondary spray water. Compared with the superheat and casting speed, the secondary cooling intensity can influence the cooling rate and temperature gradient in deeper locations, and accordingly exerts a more significant influence on the equiaxed dendritic structure.

  13. A case of cervical radiation radiculopathy resembling motor neuron disease

    International Nuclear Information System (INIS)

    Mitsunaga, Yoshihiro; Yoshimura, Takeo; Hara, Hideo; Yamada, Takeshi; Kira, Jun-ichi; Kobayashi, Takuro

    1998-01-01

    A 67-year-old man developed slowly progressive muscular weakness in the bilateral upper extremities (C5-7 regions) without signs of sensory deficit following the cervical radiation therapy (70.5 Gy) for right laryngeal cancer 4 years before. These clinical signs resembled those of lower motor neuron disease. MRI with gadolinium-DTPA, however, showed enhancement in the bilateral C5 and C6 anterior roots, suggesting the cervical radiculopathy due to radiotherapy. It is known that radiation to the spinal cord can lead to ''selective anterior horn cell injury''. This is the first case report of the cervical radiation radiculopathy, which, if without MRI, might be classified into selective anterior horn cell injury. Suggestion is made for the hypothesis that the spinal motoneuron loss in radiation myelopathy would be caused by retrograde degeneration due to anterior root damages. (author)

  14. A case of cervical radiation radiculopathy resembling motor neuron disease

    Energy Technology Data Exchange (ETDEWEB)

    Mitsunaga, Yoshihiro; Yoshimura, Takeo; Hara, Hideo; Yamada, Takeshi; Kira, Jun-ichi; Kobayashi, Takuro [Kyushu Univ., Fukuoka (Japan). Faculty of Medicine

    1998-05-01

    A 67-year-old man developed slowly progressive muscular weakness in the bilateral upper extremities (C5-7 regions) without signs of sensory deficit following the cervical radiation therapy (70.5 Gy) for right laryngeal cancer 4 years before. These clinical signs resembled those of lower motor neuron disease. MRI with gadolinium-DTPA, however, showed enhancement in the bilateral C5 and C6 anterior roots, suggesting the cervical radiculopathy due to radiotherapy. It is known that radiation to the spinal cord can lead to ``selective anterior horn cell injury``. This is the first case report of the cervical radiation radiculopathy, which, if without MRI, might be classified into selective anterior horn cell injury. Suggestion is made for the hypothesis that the spinal motoneuron loss in radiation myelopathy would be caused by retrograde degeneration due to anterior root damages. (author)

  15. RESEMBLANCE OPERATIONS AND CONCEPTUAL COMPLEXY IN ANIMAL METAPHORS

    Directory of Open Access Journals (Sweden)

    Aneider Iza Ervitia

    2012-07-01

    Full Text Available

    For over thirty years cognitive linguists have devoted much effort to the study of metaphors based on the correlation of events in human experience to the detriment of the more traditional notion of resemblance metaphor, which exploits perceived similarities among objects. Grady (1999 draws attention to this problem and calls for a more serious study of the latter type of metaphor. The present paper takes up this challenge on the basis of a small corpus of ‘animal’ metaphors in English, which are essentially based on resemblance. Contrary to previous analyses by cognitive linguists (e.g. Lakoff & Turner 1989, Ruiz de Mendoza Ibáñez, 1998, who claim that such metaphors are based on a single mapping generally involving comparable behavioral attributes, I will argue that we have a more complex situation which involves different patterns of conceptual interaction. In this respect, I have identified cases of (i animal metaphors interacting with high-level (i.e. grammatical metaphors and metonymies, of (ii (situational animal metaphors whose source domains are constructed metonymically (cf. Goossens 1990; Ruiz de Mendoza Ibáñez & Díez Velasco 2002, and of (iii animal metaphors interacting with other metaphors thereby giving rise to metaphoric amalgams (cf. Ruiz de Mendoza Ibáñez & Galera Masegosa 2011.

  16. A Para-Canalicular Abscess Resembling an Inflamed Chalazion

    Directory of Open Access Journals (Sweden)

    Diamantis Almaliotis

    2013-01-01

    Full Text Available Background. Lacrimal infections by Actinomyces are rare and commonly misdiagnosed for long periods of time. They account for 2% of all lacrimal diseases. Case Report. We report a case of a 70-year-old female patient suffering from a para-canalicular abscess in the medial canthus of the left eye, beside the lower punctum lacrimale, resembling a chalazion. Purulence exited from the punctum lacrimale due to inflammation of the inferior canaliculus (canaliculitis. When pressure was applied to the mass, a second exit of purulence was also observed under the palpebral conjunctiva below the lacrimal caruncle. A surgical excision was performed followed by administration of local antibiotic therapy. The histopathological examination of the extracted mass revealed the existence of actinomycosis. Conclusion. Persistent or recurrent infections and lumps of the eyelids should be thoroughly investigated. Actinomyces as a causative agent should be considered. Differential diagnosis is broad and should include canaliculitis, chalazion, and multiple types of neoplasias. For this reason, in nonconclusive cases, a histopathological examination should be performed.

  17. A para-canalicular abscess resembling an inflamed chalazion.

    Science.gov (United States)

    Almaliotis, Diamantis; Nakos, Elias; Siempis, Thomas; Koletsa, Triantafyllia; Kostopoulos, Ioannis; Chatzipantazi, Maria; Karampatakis, Vasileios

    2013-01-01

    Background. Lacrimal infections by Actinomyces are rare and commonly misdiagnosed for long periods of time. They account for 2% of all lacrimal diseases. Case Report. We report a case of a 70-year-old female patient suffering from a para-canalicular abscess in the medial canthus of the left eye, beside the lower punctum lacrimale, resembling a chalazion. Purulence exited from the punctum lacrimale due to inflammation of the inferior canaliculus (canaliculitis). When pressure was applied to the mass, a second exit of purulence was also observed under the palpebral conjunctiva below the lacrimal caruncle. A surgical excision was performed followed by administration of local antibiotic therapy. The histopathological examination of the extracted mass revealed the existence of actinomycosis. Conclusion. Persistent or recurrent infections and lumps of the eyelids should be thoroughly investigated. Actinomyces as a causative agent should be considered. Differential diagnosis is broad and should include canaliculitis, chalazion, and multiple types of neoplasias. For this reason, in nonconclusive cases, a histopathological examination should be performed.

  18. Autosomal dominant syndrome resembling Coffin-Siris syndrome.

    Science.gov (United States)

    Flynn, Maureen A; Milunsky, Jeff M

    2006-06-15

    Coffin-Siris syndrome is a multiple congenital anomaly/mental retardation syndrome with phenotypic variability [OMIM 135900]. The diagnosis is based solely on clinical findings, as there is currently no molecular, biochemical, or cytogenetic analysis available to confirm a diagnosis. Although typically described as an autosomal recessive disorder, autosomal dominant inheritance has also been infrequently reported. We describe a mother and her two daughters who all have features that resemble Coffin-Siris syndrome. However, this is not a completely convincing diagnosis given that hypertelorism is not a feature of Coffin-Siris syndrome and the family is relatively mildly affected. Yet, this family provides further evidence of an autosomal dominant mode of inheritance for a likely variant of Coffin-Siris syndrome (at least in some families). In addition, Sibling 1 had premature thelarche. She is the second reported individual within the spectrum of Coffin-Siris syndrome to have premature thelarche, indicating that it may be a rare clinical feature. Copyright 2006 Wiley-Liss, Inc.

  19. Atypical mycobacterial infection resembles sporotrichosis in elderly patient

    Directory of Open Access Journals (Sweden)

    Siti Nurani Fauziah

    2016-06-01

    Full Text Available Atypical mycobacterial (AM infection is caused by Mycobacterium species other than M.tuberculosis. AM skin infection has clinical manifestations that resemble M. tuberculosis infection and deep fungal infection. Laboratory workup is necessary to confirm the diagnosis. An 83-year old female came with a painful lump and swelling on her right lower extremity since three months before admission. Physical examination revealed a plaque consisting, of multiple erythematous and hyperpigmented papules and nodules, diffuse erythematous lesion, and shallow ulcers partially covered with pus and crust. Histopathological features showed tuberculoid granuloma. Direct test and periodic acid-Schiff (PAS staining of the skin biopsy found no fungal element nor acid-fast bacilli (AFB. Culture and polymerase chain reaction (PCR of M. tuberculosis were negative. The working diagnosis was atypical mycobacterial infection and treatment with 450 mg rifampicin and 100 mg minocycline daily were administered accordingly. In two months observation following the treatment, the pain was no longer exist, the ulcers were completely healed, and some nodules were in the process of healing Among other Mycobacterium spp, M.marinum is the most common cause of AM infrections. Clinical manifestation of M. marinum infection may present as solitary or multiple nodules on the hands, feet, elbows and knees with sporotrichoid spreading patern. The diagnosis of AM was established based on clinical and laboratory examination. The diagnosis was also confirmed by good clinical response to minocycline and rifampicin.

  20. Lung irradiation induces pulmonary vascular remodelling resembling pulmonary arterial hypertension.

    Science.gov (United States)

    Ghobadi, G; Bartelds, B; van der Veen, S J; Dickinson, M G; Brandenburg, S; Berger, R M F; Langendijk, J A; Coppes, R P; van Luijk, P

    2012-04-01

    Pulmonary arterial hypertension (PAH) is a commonly fatal pulmonary vascular disease that is often diagnosed late and is characterised by a progressive rise in pulmonary vascular resistance resulting from typical vascular remodelling. Recent data suggest that vascular damage plays an important role in the development of radiation-induced pulmonary toxicity. Therefore, the authors investigated whether irradiation of the lung also induces pulmonary hypertension. Different sub-volumes of the rat lung were irradiated with protons known to induce different levels of pulmonary vascular damage. Early loss of endothelial cells and vascular oedema were observed in the irradiation field and in shielded parts of the lung, even before the onset of clinical symptoms. 8 weeks after irradiation, irradiated volume-dependent vascular remodelling was observed, correlating perfectly with pulmonary artery pressure, right ventricle hypertrophy and pulmonary dysfunction. The findings indicate that partial lung irradiation induces pulmonary vascular remodelling resulting from acute pulmonary endothelial cell loss and consequential pulmonary hypertension. Moreover, the close resemblance of the observed vascular remodelling with vascular lesions in PAH makes partial lung irradiation a promising new model for studying PAH.

  1. Extended retroperitoneal necrotizing fasciitis with genital involvement, resembling fournier gangrene.

    Science.gov (United States)

    Sugimoto, Motokazu; Matsuura, Kenji; Takayama, Hiroshi; Kayo, Munefumi; Ie, Tomotsugu

    2010-10-01

    Necrotizing fasciitis is a serious infection that originates in the subcutaneous tissues. Although many reports have been published about necrotizing infections of other anatomical sites, retroperitoneal necrotizing soft tissue infection is a rare entity that has been described in only a few case reports. The etiology and clinical course of retroperitoneal necrotizing fasciitis can be variable and it is often difficult to identify the etiology of the infective process. We report a 58-year-old man with rapidly progressive, gas-producing, necrotizing inflammation in the retroperitoneum, complicated with genital involvement resembling Fournier gangrene. The patient was managed successfully by aggressive drainage, debridement, and sequential laparotomies to track and control the extensive necrosis of the retroperitoneum and perineum, in addition to systemic care to control sepsis. After his general condition stabilized, early rectosigmoid adenocarcinoma was identified and resected curatively. He remained well at follow up, six months after discharge. In retrospect, the trigger of the disease process was unclear. Although it was believed possibly to be due to the colon lesion, adenocarcinoma of the rectosigmoid colon was identified and the patient was managed successfully. Similar to necrotizing infections at other anatomical sites, early diagnosis and timely surgical intervention and systemic antimicrobial therapy are mandatory for treating patients with retroperitoneal necrotizing fasciitis.

  2. Neurogenesis in Aplysia californica resembles nervous system formation in vertebrates

    International Nuclear Information System (INIS)

    Jacob, M.H.

    1984-01-01

    The pattern of neurogenesis of the central nervous system of Aplysia californica was investigated by [ 3 H]thymidine autoradiography. Large numbers of animals at a series of early developmental stages were labeled with [ 3 H]thymidine for 24 or 48 hr and were subsequently sampled at specific intervals throughout the life cycle. I found that proliferative zones, consisting of columnar and placodal ectodermal cells, are established in regions of the body wall adjacent to underlying mesodermal cells. Mitosis in the proliferative zones generates a population of cells which leave the surface and migrate inward to join the nearby forming ganglia. Tracing specific [ 3 H]thymidine-labeled cells from the body wall to a particular ganglion and within the ganglion over time suggests that the final genomic replication of the neuronal precursors occurs before the cells join the ganglion while glial cell precursors and differentiating glial cells continue to divide within the ganglion for some time. Ultrastructural examination of the morphological features of the few mitosing cells observed within the Aplysia central nervous system supports this interpretation. The pattern of neurogenesis in the Aplysia central nervous system resembles the proliferation of cells in the neural tube and the migration of neural crest and ectodermal placode cells in the vertebrate nervous system but differs from the pattern described for other invertebrates

  3. Extrinsic Repair of Injured Dendrites as a Paradigm for Regeneration by Fusion in Caenorhabditis elegans

    Science.gov (United States)

    Oren-Suissa, Meital; Gattegno, Tamar; Kravtsov, Veronika; Podbilewicz, Benjamin

    2017-01-01

    Injury triggers regeneration of axons and dendrites. Research has identified factors required for axonal regeneration outside the CNS, but little is known about regeneration triggered by dendrotomy. Here, we study neuronal plasticity triggered by dendrotomy and determine the fate of complex PVD arbors following laser surgery of dendrites. We find that severed primary dendrites grow toward each other and reconnect via branch fusion. Simultaneously, terminal branches lose self-avoidance and grow toward each other, meeting and fusing at the tips via an AFF-1-mediated process. Ectopic branch growth is identified as a step in the regeneration process required for bypassing the lesion site. Failure of reconnection to the severed dendrites results in degeneration of the distal end of the neuron. We discover pruning of excess branches via EFF-1 that acts to recover the original wild-type arborization pattern in a late stage of the process. In contrast, AFF-1 activity during dendritic auto-fusion is derived from the lateral seam cells and not autonomously from the PVD neuron. We propose a model in which AFF-1-vesicles derived from the epidermal seam cells fuse neuronal dendrites. Thus, EFF-1 and AFF-1 fusion proteins emerge as new players in neuronal arborization and maintenance of arbor connectivity following injury in Caenorhabditis elegans. Our results demonstrate that there is a genetically determined multi-step pathway to repair broken dendrites in which EFF-1 and AFF-1 act on different steps of the pathway. EFF-1 is essential for dendritic pruning after injury and extrinsic AFF-1 mediates dendrite fusion to bypass injuries. PMID:28283540

  4. DIXDC1 Phosphorylation and Control of Dendritic Morphology Are Impaired by Rare Genetic Variants

    Directory of Open Access Journals (Sweden)

    Vickie Kwan

    2016-11-01

    Full Text Available The development of neural connectivity is essential for brain function, and disruption of this process is associated with autism spectrum disorders (ASDs. DIX domain containing 1 (DIXDC1 has previously been implicated in neurodevelopmental disorders, but its role in postnatal brain function remains unknown. Using a knockout mouse model, we determined that DIXDC1 is a regulator of excitatory neuron dendrite development and synapse function in the cortex. We discovered that MARK1, previously linked to ASDs, phosphorylates DIXDC1 to regulate dendrite and spine development through modulation of the cytoskeletal network in an isoform-specific manner. Finally, rare missense variants in DIXDC1 were identified in ASD patient cohorts via genetic sequencing. Interestingly, the variants inhibit DIXDC1 isoform 1 phosphorylation, causing impairment to dendrite and spine growth. These data reveal that DIXDC1 is a regulator of cortical dendrite and synaptic development and provide mechanistic insight into morphological defects associated with neurodevelopmental disorders.

  5. Disruption of an Aligned Dendritic Network by Bubbles During Re-Melting in a Microgravity Environment

    Science.gov (United States)

    Grugel, Richard N.; Brush, Lucien N.; Anilkumar, Amrutur V.

    2012-01-01

    The quiescent Microgravity environment can be quite dynamic. Thermocapillary flow about "large" static bubbles on the order of 1mm in diameter was easily observed by following smaller tracer bubbles. The bubble induced flow was seen to disrupt a large dendritic array, effectively distributing free branches about the solid-liquid interface. "Small" dynamic bubbles were observed to travel at fast velocities through the mushy zone with the implication of bringing/detaching/redistributing dendrite arm fragments at the solid-liquid interface. Large and small bubbles effectively re-orient/re-distribute dendrite branches/arms/fragments at the solid liquid interface. Subsequent initiation of controlled directional solidification results in growth of dendrites having random orientations which significantly compromises the desired science.

  6. Do general radiographic examinations resemble a person-centred environment?

    International Nuclear Information System (INIS)

    Hayre, C.M.; Blackman, S.; Eyden, A.

    2016-01-01

    Aim and objective: It is argued whether general radiographic examinations adhere to a person-centred approach within the direct digital radiography (DDR) environment. General radiographic examinations continue to increase and constitute approximately 90% of all examinations undertaken in the clinical environment. This study explored the potential impact patients experience whilst undergoing general imaging examinations. Method: An ethnographic methodology provided insight of two general radiography environments in the United Kingdom (UK) using participant observation and semi-structured interviews. Findings: The findings highlighted an ‘in and out’ culture whereby patients are ‘hurried’ and ‘rushed’ out of X-ray rooms in response to increasing time pressures experienced by diagnostic radiographers. In addition, this study challenged that patients may begin to rank ‘speed’ and ‘waiting times’ above other elements of radiographic care thus presenting new challenges for radiographers within the clinical environment. Conclusion: It is asserted that radiographers should remain holistic healthcare professionals and not begin to resemble operators on the production line. Further, it challenges whether patients are beginning to rank aspects of radiographic care within contemporary practices. Advances in knowledge: Few studies have explored the radiographer–patient relationship within the DDR environment, yet this study provides insight of person-centred practices within contemporary practices. - Highlights: • Challenges whether the use of DDR conforms to a person-centred approach. • Challenges whether radiographers are ‘treating patients as persons’ using DDR. • Patients may begin to rank ‘speed’ and ‘waiting times’ above other aspects of radiographic care.

  7. Predator-Resembling Aversive Conditioning for Managing Habituated Wildlife

    Directory of Open Access Journals (Sweden)

    Elsabé Louise Kloppers

    2005-06-01

    Full Text Available Wildlife habituation near urban centers can disrupt natural ecological processes, destroy habitat, and threaten public safety. Consequently, management of habituated animals is typically invasive and often includes translocation of these animals to remote areas and sometimes even their destruction. Techniques to prevent or reverse habituation and other forms of in situ management are necessary to balance ecological and social requirements, but they have received very little experimental attention to date. This study compared the efficacy of two aversive conditioning treatments that used either humans or dogs to create sequences resembling chases by predators, which, along with a control category, were repeatedly and individually applied to 24 moderately habituated, radio-collared elk in Banff National Park during the winter of 2001-2002. Three response variables were measured before and after treatment. Relative to untreated animals, the distance at which elk fled from approaching humans, i.e., the flight response distance, increased following both human and dog treatments, but there was no difference between the two treatments. The proportion of time spent in vigilance postures decreased for all treatment groups, without differences among groups, suggesting that this behavior responded mainly to seasonal effects. The average distance between elk locations and the town boundary, measured once daily by telemetry, significantly increased for human-conditioned elk. One of the co-variates we measured, wolf activity, exerted counteracting effects on conditioning effects; flight response distances and proximity to the town site were both lower when wolf activity was high. This research demonstrates that it is possible to temporarily modify aspects of the behavior of moderately habituated elk using aversive conditioning, suggests a method for reducing habituation in the first place, and provides a solution for Banff and other jurisdictions to manage

  8. Gait analysis in a mouse model resembling Leigh disease.

    Science.gov (United States)

    de Haas, Ria; Russel, Frans G; Smeitink, Jan A

    2016-01-01

    Leigh disease (LD) is one of the clinical phenotypes of mitochondrial OXPHOS disorders and also known as sub-acute necrotizing encephalomyelopathy. The disease has an incidence of 1 in 77,000 live births. Symptoms typically begin early in life and prognosis for LD patients is poor. Currently, no clinically effective treatments are available. Suitable animal and cellular models are necessary for the understanding of the neuropathology and the development of successful new therapeutic strategies. In this study we used the Ndufs4 knockout (Ndufs4(-/-)) mouse, a model of mitochondrial complex I deficiency. Ndusf4(-/-) mice exhibit progressive neurodegeneration, which closely resemble the human LD phenotype. When dissecting behavioral abnormalities in animal models it is of great importance to apply translational tools that are clinically relevant. To distinguish gait abnormalities in patients, simple walking tests can be assessed, but in animals this is not easy. This study is the first to demonstrate automated CatWalk gait analysis in the Ndufs4(-/-) mouse model. Marked differences were noted between Ndufs4(-/-) and control mice in dynamic, static, coordination and support parameters. Variation of walking speed was significantly increased in Ndufs4(-/-) mice, suggesting hampered and uncoordinated gait. Furthermore, decreased regularity index, increased base of support and changes in support were noted in the Ndufs4(-/-) mice. Here, we report the ability of the CatWalk system to sensitively assess gait abnormalities in Ndufs4(-/-) mice. This objective gait analysis can be of great value for intervention and drug efficacy studies in animal models for mitochondrial disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. Low Power Dendritic Computation for Wordspotting

    Directory of Open Access Journals (Sweden)

    Stephen Nease

    2013-05-01

    Full Text Available In this paper, we demonstrate how a network of dendrites can be used to build the state decoding block of a wordspotter similar to a Hidden Markov Model (HMM classifier structure. We present simulation and experimental data for a single line dendrite and also experimental results for a dendrite-based classifier structure. This work builds on previously demonstrated building blocks of a neural network: the channel, synapses and dendrites using CMOS circuits. These structures can be used for speech and pattern recognition. The computational efficiency of such a system is >10 MMACs/μW as compared to Digital Systems which perform 10 MMACs/mW.

  10. Dendritic Branch Intersections Are Structurally Regulated Targets for Efficient Axonal Wiring and Synaptic Clustering

    Science.gov (United States)

    Pinchas, Monika; Baranes, Danny

    2013-01-01

    Synaptic clustering on dendritic branches enhances plasticity, input integration and neuronal firing. However, the mechanisms guiding axons to cluster synapses at appropriate sites along dendritic branches are poorly understood. We searched for such a mechanism by investigating the structural overlap between dendritic branches and axons in a simplified model of neuronal networks - the hippocampal cell culture. Using newly developed software, we converted images of meshes of overlapping axonal and dendrites into topological maps of intersections, enabling quantitative study of overlapping neuritic geometry at the resolution of single dendritic branch-to-branch and axon-to-branch crossings. Among dendro-dendritic crossing configurations, it was revealed that the orientations through which dendritic branches cross is a regulated attribute. While crossing angle distribution among branches thinner than 1 µm appeared to be random, dendritic branches 1 µm or wider showed a preference for crossing each other at angle ranges of either 50°–70° or 80°–90°. It was then found that the dendro-dendritic crossings themselves, as well as their selective angles, both affected the path of axonal growth. Axons displayed 4 fold stronger tendency to traverse within 2 µm of dendro-dendritic intersections than at farther distances, probably to minimize wiring length. Moreover, almost 70% of the 50°–70° dendro-denritic crossings were traversed by axons from the obtuse angle’s zone, whereas only 15% traversed through the acute angle’s zone. By contrast, axons showed no orientation restriction when traversing 80°–90° crossings. When such traverse behavior was repeated by many axons, they converged in the vicinity of dendro-dendritic intersections, thereby clustering their synaptic connections. Thus, the vicinity of dendritic branch-to-branch crossings appears to be a regulated structure used by axons as a target for efficient wiring and as a preferred site for synaptic

  11. Three-dimensional morphologies of inclined equiaxed dendrites growing under forced convection by phase-field-lattice Boltzmann method

    Science.gov (United States)

    Sakane, Shinji; Takaki, Tomohiro; Ohno, Munekazu; Shibuta, Yasushi; Shimokawabe, Takashi; Aoki, Takayuki

    2018-02-01

    Three-dimensional growth morphologies of equiaxed dendrites growing under forced convection, with their preferred growth direction inclined from the flow direction, were investigated by performing large-scale phase-field lattice Boltzmann simulations on a graphical-processing-unit supercomputer. The tip velocities of the dendrite arms with their preferred growth directions inclined toward the upstream and downstream directions increased and decreased, respectively, as a result of forced convection. In addition, the tip velocities decreased monotonically as the angle between the preferred growth direction and the upstream direction increased. Here, the degree of acceleration of the upstream tips was larger than the degree of deceleration of the downstream tips. The angles between the actual tip growth directions and the preferred growth direction of the dendrite arms exhibited a characteristic change with two local maxima and two local minima.

  12. LMTK1 regulates dendritic formation by regulating movement of Rab11A-positive endosomes.

    Science.gov (United States)

    Takano, Tetsuya; Urushibara, Tomoki; Yoshioka, Nozomu; Saito, Taro; Fukuda, Mitsunori; Tomomura, Mineko; Hisanaga, Shin-Ichi

    2014-06-01

    Neurons extend two types of neurites-axons and dendrites-that differ in structure and function. Although it is well understood that the cytoskeleton plays a pivotal role in neurite differentiation and extension, the mechanisms by which membrane components are supplied to growing axons or dendrites is largely unknown. We previously reported that the membrane supply to axons is regulated by lemur kinase 1 (LMTK1) through Rab11A-positive endosomes. Here we investigate the role of LMTK1 in dendrite formation. Down-regulation of LMTK1 increases dendrite growth and branching of cerebral cortical neurons in vitro and in vivo. LMTK1 knockout significantly enhances the prevalence, velocity, and run length of anterograde movement of Rab11A-positive endosomes to levels similar to those expressing constitutively active Rab11A-Q70L. Rab11A-positive endosome dynamics also increases in the cell body and growth cone of LMTK1-deficient neurons. Moreover, a nonphosphorylatable LMTK1 mutant (Ser34Ala, a Cdk5 phosphorylation site) dramatically promotes dendrite growth. Thus LMTK1 negatively controls dendritic formation by regulating Rab11A-positive endosomal trafficking in a Cdk5-dependent manner, indicating the Cdk5-LMTK1-Rab11A pathway as a regulatory mechanism of dendrite development as well as axon outgrowth. © 2014 Takano et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).

  13. Interfacial wave theory for dendritic structure of a growing needle crystal. I - Local instability mechanism. II - Wave-emission mechanism at the turning point

    Science.gov (United States)

    Xu, Jian-Jun

    1989-01-01

    The complicated dendritic structure of a growing needle crystal is studied on the basis of global interfacial wave theory. The local dispersion relation for normal modes is derived in a paraboloidal coordinate system using the multiple-variable-expansion method. It is shown that the global solution in a dendrite growth process incorporates the morphological instability factor and the traveling wave factor.

  14. Fast generation of dendritic cells

    DEFF Research Database (Denmark)

    Kvistborg, P; Bøgh, Marie; Pedersen, A W

    2009-01-01

    Dendritic cells (DC) are potent antigen presenting cells capable of inducing immune responses. DC are widely used as vaccine adjuvant in experimental clinical settings. DC-based vaccines are normally generated using a standard 8day DC protocol (SDDC). In attempts to shorten the vaccine production...... SDDC to the IL-10 inducing stimulus of TLR ligands (R848 and LPS). Thus to determine the clinical relevance of fast DC protocols in cancer settings, small phase I trials should be conducted monitoring regulatory T cells carefully....

  15. Targeting vaccines to dendritic cells

    DEFF Research Database (Denmark)

    Foged, Camilla; Sundblad, Anne; Hovgaard, Lars

    2002-01-01

    Dendritic cells (DC) are specialized antigen presenting cells (APC) with a remarkable ability to take up antigens and stimulate major histocompatibility complex (MHC)-restricted specific immune responses. Recent discoveries have shown that their role in initiating primary immune responses seems...... to be far superior to that of B-cells and macrophages. DC are localized at strategic places in the body at sites used by pathogens to enter the organism, and are thereby in an optimal position to capture antigens. In general, vaccination strategies try to mimic the invasiveness of the pathogens. DC...

  16. Effect of the dendritic morphology on hot tearing of carbon steels

    International Nuclear Information System (INIS)

    Ridolfi, M R

    2016-01-01

    Hot tears form during solidification in the brittle region of the dendritic front. Most hot tearing criteria are based on solid and fluid mechanics, being the phenomenon strictly depending on the solid resistance to applied strains and on the liquid capability of filling the void spaces. Modelling both mechanisms implies the precise description of the dendritic morphology. To this scope, the theory of coalescence of the dendritic arms at grain boundaries of Rappaz et al. has been applied, in this work, to the columnar growth of carbon steels by means of a simple mathematical model. Depending on the alloy composition, solid bridging starts at solid fractions down to about 0.8 and up to above 0.995 (very low carbon). The morphology of the brittle region changes drastically with increasing carbon and adding other solutes. In particular, ferritic dendrites, typical of low carbon steels, tend to offer short and wide interdendritic spaces to the surrounding liquid making possible their complete filling, and few solid bridges; peritectic steels show the rise of austenite growing and bridging rapidly in the interdendritic spaces, preventing void formation; austenitic dendrites form long and narrow interdendritic spaces difficult to reach for the liquid and with a lot of solid bridges. Sulphur addition mainly acts in delaying the coalescence end, more markedly in ferritic dendrites. (paper)

  17. The Origin of Spousal Resemblance for Alcohol Use Disorder.

    Science.gov (United States)

    Kendler, Kenneth S; Lönn, Sara Larsson; Salvatore, Jessica; Sundquist, Jan; Sundquist, Kristina

    2018-03-01

    Although spouses strongly resemble one another in their risk for alcohol use disorder (AUD), the causes of this association remain unclear. To examine longitudinally, in first marriages, the association of a first registration for AUD in one spouse with risk of registration in his or her partner and to explore changes in the risk for AUD registration in individuals with multiple marriages as they transition from a spouse with AUD to one without or vice versa. Population-wide Swedish registries were used to identify individuals born in Sweden between 1960 and 1990 who were married before the end of study follow-up on December 31, 2013. The study included 8562 marital pairs with no history of AUD registration prior to their first marriage and an AUD registration in 1 spouse during marriage and 4891 individuals with multiple marriages whose first spouse had no AUD registration and second spouse did or vice versa. Final statistical analyses were conducted from August 15 to September 1, 2017. A spousal onset or history of AUD registration. Alcohol use disorder registration in national medical, criminal, or pharmacy registries. Among the 8562 marital pairs (5883 female probands and 2679 male probands; mean [SD] age at marriage, 29.2 [5.7] years) in first marriages, the hazard ratio of AUD registration in wives immediately after the first AUD registration in their husbands was 13.82, which decreased 2 years later to 3.75. The hazard ratio of AUD registration in husbands after the first AUD registration in their wives was 9.21, which decreased 2 years later to 3.09. Among the 4891 individuals with multiple marriages (1439 women and 3452 men; mean [SD] age at first marriage, 25.5 [4.2] years), when individuals transitioned from a first marriage to a spouse with AUD to a second marriage to a spouse without AUD, the hazard ratio for AUD registration was 0.50 (95% CI, 0.42-0.59) in women and 0.51 (95% CI, 0.44-0.59) in men. After a first marriage to a spouse without AUD, the

  18. Phenotypic and functional markers for 1alpha,25-dihydroxyvitamin D(3)-modified regulatory dendritic cells

    DEFF Research Database (Denmark)

    Pedersen, A W; Holmstrøm, K; Jensen, S S

    2009-01-01

    be measured with simple methods to identify regulatory DCs that are applicable for future clinical studies. Human DCs were generated from peripheral blood monocytes in the presence of 1alpha,25-dihydroxyvitamin D(3) (VD3), which gave rise to a phenotype that resembles immature DCs, with the exception of high......The clinical use of dendritic cells (DCs) to induce antigen-specific immune tolerance has been hampered by the lack of a widely acknowledged method for generating human regulatory DCs but even more so by the non-existence of reliable markers. Thus, we set out to find reliable markers that can...

  19. Packing of sedimenting equiaxed dendrites

    Science.gov (United States)

    Olmedilla, Antonio; Založnik, Miha; Rouat, Bernard; Combeau, Hervé

    2018-01-01

    The packing of free-floating crystal grains during solidification has a strong impact on the phase-change process as well as on the structure and the defects in the solidified material. The packing fraction is affected by the particular dendritic morphology of the grains and by their low inertia resulting from the small density difference between solid and liquid. Understanding the grain packing phenomenon during metal alloy solidification is not experimentally possible since packing is coupled to many other phenomena. We therefore investigate the packing of equiaxed dendrites on a model system, consisting of fixed-shape nonconvex model particles sedimenting in conditions hydrodynamically similar to those encountered in solidifying metals. We perform numerical simulations by a discrete-element model and experiments with transparent liquids in a sedimentation column. The combination of experiments and simulations enables us to determine the packing fraction as a function of (i) the grain morphology, expressed by a shape parameter, and (ii) the hydrodynamic conditions, expressed by the particle Stokes number.

  20. Synthesis of Dendritic Silver Nanoparticles and Their Applications as SERS Substrates

    Directory of Open Access Journals (Sweden)

    Jinshan Yu

    2013-01-01

    Full Text Available The silver nanoparticles are synthesized by electrodeposition in ultradilute Ag+ concentration electrolyte under high overpotential. The as prepared Ag nanoparticles, with the sizes ranging from 20 to 30 nm, are arrayed orderly and formed dendritic morphology. The formation of this special dendritic nanoparticle structure can be contributed to the relatively high growth rate and the preferential growth directions along 111 due to the high overpotential, as well as the relative small number of Ag+ ions arriving at the Ag crystal surface per unit time due to the ultradilute Ag+ concentration. Surface enhanced Raman scattering (SERS experiments reveal that the as-prepared dendritic Ag nanoparticles possess high SERS properties and can be used as a candidate substrate for practical SERS applications to detect the Rhodamine 6G molecules.

  1. Overview of the Tusas Code for Simulation of Dendritic Solidification

    Energy Technology Data Exchange (ETDEWEB)

    Trainer, Amelia J. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Newman, Christopher Kyle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Francois, Marianne M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-07

    The aim of this project is to conduct a parametric investigation into the modeling of two dimensional dendrite solidification, using the phase field model. Specifically, we use the Tusas code, which is for coupled heat and phase-field simulation of dendritic solidification. Dendritic solidification, which may occur in the presence of an unstable solidification interface, results in treelike microstructures that often grow perpendicular to the rest of the growth front. The interface may become unstable if the enthalpy of the solid material is less than that of the liquid material, or if the solute is less soluble in solid than it is in liquid, potentially causing a partition [1]. A key motivation behind this research is that a broadened understanding of phase-field formulation and microstructural developments can be utilized for macroscopic simulations of phase change. This may be directly implemented as a part of the Telluride project at Los Alamos National Laboratory (LANL), through which a computational additive manufacturing simulation tool is being developed, ultimately to become part of the Advanced Simulation and Computing Program within the U.S. Department of Energy [2].

  2. The actin-binding protein capulet genetically interacts with the microtubule motor kinesin to maintain neuronal dendrite homeostasis.

    Directory of Open Access Journals (Sweden)

    Paul M B Medina

    Full Text Available BACKGROUND: Neurons require precise cytoskeletal regulation within neurites, containing microtubule tracks for cargo transport in axons and dendrites or within synapses containing organized actin. Due to the unique architecture and specialized function of neurons, neurons are particularly susceptible to perturbation of the cytoskeleton. Numerous actin-binding proteins help maintain proper cytoskeletal regulation. METHODOLOGY/PRINCIPAL FINDINGS: From a Drosophila forward genetic screen, we identified a mutation in capulet--encoding a conserved actin-binding protein--that causes abnormal aggregates of actin within dendrites. Through interaction studies, we demonstrate that simultaneous genetic inactivation of capulet and kinesin heavy chain, a microtubule motor protein, produces elongate cofilin-actin rods within dendrites but not axons. These rods resemble actin-rich structures induced in both mammalian neurodegenerative and Drosophila Alzheimer's models, but have not previously been identified by loss of function mutations in vivo. We further demonstrate that mitochondria, which are transported by Kinesin, have impaired distribution along dendrites in a capulet mutant. While Capulet and Cofilin may biochemically cooperate in certain circumstances, in neuronal dendrites they genetically antagonize each other. CONCLUSIONS/SIGNIFICANCE: The present study is the first molecularly defined loss of function demonstration of actin-cofilin rods in vivo. This study suggests that simultaneous, seemingly minor perturbations in neuronal dendrites can synergize producing severe abnormalities affecting actin, microtubules and mitochondria/energy availability in dendrites. Additionally, as >90% of Alzheimer's and Parkinson's cases are sporadic this study suggests mechanisms by which multiple mutations together may contribute to neurodegeneration instead of reliance on single mutations to produce disease.

  3. Structural homeostasis: compensatory adjustments of dendritic arbor geometry in response to variations of synaptic input.

    Directory of Open Access Journals (Sweden)

    Marco Tripodi

    2008-10-01

    Full Text Available As the nervous system develops, there is an inherent variability in the connections formed between differentiating neurons. Despite this variability, neural circuits form that are functional and remarkably robust. One way in which neurons deal with variability in their inputs is through compensatory, homeostatic changes in their electrical properties. Here, we show that neurons also make compensatory adjustments to their structure. We analysed the development of dendrites on an identified central neuron (aCC in the late Drosophila embryo at the stage when it receives its first connections and first becomes electrically active. At the same time, we charted the distribution of presynaptic sites on the developing postsynaptic arbor. Genetic manipulations of the presynaptic partners demonstrate that the postsynaptic dendritic arbor adjusts its growth to compensate for changes in the activity and density of synaptic sites. Blocking the synthesis or evoked release of presynaptic neurotransmitter results in greater dendritic extension. Conversely, an increase in the density of presynaptic release sites induces a reduction in the extent of the dendritic arbor. These growth adjustments occur locally in the arbor and are the result of the promotion or inhibition of growth of neurites in the proximity of presynaptic sites. We provide evidence that suggest a role for the postsynaptic activity state of protein kinase A in mediating this structural adjustment, which modifies dendritic growth in response to synaptic activity. These findings suggest that the dendritic arbor, at least during early stages of connectivity, behaves as a homeostatic device that adjusts its size and geometry to the level and the distribution of input received. The growing arbor thus counterbalances naturally occurring variations in synaptic density and activity so as to ensure that an appropriate level of input is achieved.

  4. Dendritic Cells in the Cancer Microenvironment

    Directory of Open Access Journals (Sweden)

    Yang Ma, Galina V. Shurin, Zhu Peiyuan, Michael R. Shurin

    2013-01-01

    Full Text Available The complexity of the tumor immunoenvironment is underscored by the emergence and discovery of different subsets of immune effectors and regulatory cells. Tumor-induced polarization of immune cell differentiation and function makes this unique environment even more intricate and variable. Dendritic cells (DCs represent a special group of cells that display different phenotype and activity at the tumor site and exhibit differential pro-tumorigenic and anti-tumorigenic functions. DCs play a key role in inducing and maintaining the antitumor immunity, but in the tumor environment their antigen-presenting function may be lost or inefficient. DCs might be also polarized into immunosuppressive/tolerogenic regulatory DCs, which limit activity of effector T cells and support tumor growth and progression. Although various factors and signaling pathways have been described to be responsible for abnormal functioning of DCs in cancer, there are still no feasible therapeutic modalities available for preventing or reversing DC malfunction in tumor-bearing hosts. Thus, better understanding of DC immunobiology in cancer is pivotal for designing novel or improved therapeutic approaches that will allow proper functioning of DCs in patients with cancer.

  5. Nonbilayer Phospholipid Arrangements Are Toll-Like Receptor-2/6 and TLR-4 Agonists and Trigger Inflammation in a Mouse Model Resembling Human Lupus

    Science.gov (United States)

    Wong-Baeza, Carlos; Tescucano, Alonso; Astudillo, Horacio; Reséndiz, Albany; Landa, Carla; España, Luis; Serafín-López, Jeanet; Estrada-García, Iris; Estrada-Parra, Sergio; Flores-Romo, Leopoldo; Wong, Carlos; Baeza, Isabel

    2015-01-01

    Systemic lupus erythematosus is characterized by dysregulated activation of T and B cells and autoantibodies to nuclear antigens and, in some cases, lipid antigens. Liposomes with nonbilayer phospholipid arrangements induce a disease resembling human lupus in mice, including IgM and IgG antibodies against nonbilayer phospholipid arrangements. As the effect of these liposomes on the innate immune response is unknown and innate immune system activation is necessary for efficient antibody formation, we evaluated the effect of these liposomes on Toll-like receptor (TLR) signaling, cytokine production, proinflammatory gene expression, and T, NKT, dendritic, and B cells. Liposomes induce TLR-4- and, to a lesser extent, TLR-2/TLR-6-dependent signaling in TLR-expressing human embryonic kidney (HEK) cells and bone marrow-derived macrophages. Mice with the lupus-like disease had increased serum concentrations of proinflammatory cytokines, C3a and C5a; they also had more TLR-4-expressing splenocytes, a higher expression of genes associated with TRIF-dependent TLR-4-signaling and complement activation, and a lower expression of apoptosis-related genes, compared to healthy mice. The percentage of NKT and the percentage and activation of dendritic and B2 cells were also increased. Thus, TLR-4 and TLR-2/TLR-6 activation by nonbilayer phospholipid arrangements triggers an inflammatory response that could contribute to autoantibody production and the generation of a lupus-like disease in mice. PMID:26568960

  6. Nonbilayer Phospholipid Arrangements Are Toll-Like Receptor-2/6 and TLR-4 Agonists and Trigger Inflammation in a Mouse Model Resembling Human Lupus

    Directory of Open Access Journals (Sweden)

    Carlos Wong-Baeza

    2015-01-01

    Full Text Available Systemic lupus erythematosus is characterized by dysregulated activation of T and B cells and autoantibodies to nuclear antigens and, in some cases, lipid antigens. Liposomes with nonbilayer phospholipid arrangements induce a disease resembling human lupus in mice, including IgM and IgG antibodies against nonbilayer phospholipid arrangements. As the effect of these liposomes on the innate immune response is unknown and innate immune system activation is necessary for efficient antibody formation, we evaluated the effect of these liposomes on Toll-like receptor (TLR signaling, cytokine production, proinflammatory gene expression, and T, NKT, dendritic, and B cells. Liposomes induce TLR-4- and, to a lesser extent, TLR-2/TLR-6-dependent signaling in TLR-expressing human embryonic kidney (HEK cells and bone marrow-derived macrophages. Mice with the lupus-like disease had increased serum concentrations of proinflammatory cytokines, C3a and C5a; they also had more TLR-4-expressing splenocytes, a higher expression of genes associated with TRIF-dependent TLR-4-signaling and complement activation, and a lower expression of apoptosis-related genes, compared to healthy mice. The percentage of NKT and the percentage and activation of dendritic and B2 cells were also increased. Thus, TLR-4 and TLR-2/TLR-6 activation by nonbilayer phospholipid arrangements triggers an inflammatory response that could contribute to autoantibody production and the generation of a lupus-like disease in mice.

  7. Dendritic Cell-Targeted Vaccines

    Science.gov (United States)

    Cohn, Lillian; Delamarre, Lélia

    2014-01-01

    Despite significant effort, the development of effective vaccines inducing strong and durable T-cell responses against intracellular pathogens and cancer cells has remained a challenge. The initiation of effector CD8+ T-cell responses requires the presentation of peptides derived from internalized antigen on class I major histocompatibility complex molecules by dendritic cells (DCs) in a process called cross-presentation. A current strategy to enhance the effectiveness of vaccination is to deliver antigens directly to DCs. This is done via selective targeting of antigen using monoclonal antibodies directed against endocytic receptors on the surface of the DCs. In this review, we will discuss considerations relevant to the design of such vaccines: the existence of DC subsets with specialized functions, the impact of the antigen intracellular trafficking on cross-presentation, and the influence of maturation signals received by DCs on the outcome of the immune response. PMID:24910635

  8. Modulation of dendritic spine development and plasticity by BDNF and vesicular trafficking: fundamental roles in neurodevelopmental disorders associated with mental retardation and autism.

    Science.gov (United States)

    Chapleau, Christopher A; Larimore, Jennifer L; Theibert, Anne; Pozzo-Miller, Lucas

    2009-09-01

    The process of axonal and dendritic development establishes the synaptic circuitry of the central nervous system (CNS) and is the result of interactions between intrinsic molecular factors and the external environment. One growth factor that has a compelling function in neuronal development is the neurotrophin brain-derived neurotrophic factor (BDNF). BDNF participates in axonal and dendritic differentiation during embryonic stages of neuronal development, as well as in the formation and maturation of dendritic spines during postnatal development. Recent studies have also implicated vesicular trafficking of BDNF via secretory vesicles, and both secretory and endosomal trafficking of vesicles containing synaptic proteins, such as neurotransmitter and neurotrophin receptors, in the regulation of axonal and dendritic differentiation, and in dendritic spine morphogenesis. Several genes that are either mutated or deregulated in neurodevelopmental disorders associated with mental retardation have now been identified, and several mouse models of these disorders have been generated and characterized. Interestingly, abnormalities in dendritic and synaptic structure are consistently observed in human neurodevelopmental disorders associated with mental retardation, and in mouse models of these disorders as well. Abnormalities in dendritic and synaptic differentiation are thought to underlie altered synaptic function and network connectivity, thus contributing to the clinical outcome. Here, we review the roles of BDNF and vesicular trafficking in axonal and dendritic differentiation in the context of dendritic and axonal morphological impairments commonly observed in neurodevelopmental disorders associated with mental retardation.

  9. TGFβR signalling controls CD103+CD11b+ dendritic cell development in the intestine

    NARCIS (Netherlands)

    L.J. Bain (Lisa); Montgomery, J. (J.); C.L. Scott (C.); J.M. Kel (Junda); M.J.H. Girard-Madoux (Mathilde); L. Martens (Liesbet); Zangerle-Murray, T.F.P. (T. F.P.); J.L. Ober-Blöbaum (Julia); D.J. Lindenbergh-Kortleve (Dicky); J.N. Samsom (Janneke); S. Henri (Sandrine); T. Lawrence (Toby); Y. Saeys (Yvan); B. Malissen (Bernard); M. Dalod (Marc); B.E. Clausen (Bjorn); Mowat, A.M. (A. McI.)

    2017-01-01

    textabstractCD103+CD11b+ dendritic cells (DCs) are unique to the intestine, but the factors governing their differentiation are unclear. Here we show that transforming growth factor receptor 1 (TGFβR1) has an indispensable, cell intrinsic role in the development of these cells. Deletion of Tgfbr1

  10. Dendritic ion channelopathy in acquired epilepsy

    Science.gov (United States)

    Poolos, Nicholas P.; Johnston, Daniel

    2012-01-01

    Summary Ion channel dysfunction or “channelopathy” is a proven cause of epilepsy in the relatively uncommon genetic epilepsies with Mendelian inheritance. But numerous examples of acquired channelopathy in experimental animal models of epilepsy following brain injury have also been demonstrated. Our understanding of channelopathy has grown due to advances in electrophysiology techniques that have allowed the study of ion channels in the dendrites of pyramidal neurons in cortex and hippocampus. The apical dendrites of pyramidal neurons comprise the vast majority of neuronal surface membrane area, and thus the majority of the neuronal ion channel population. Investigation of dendritic ion channels has demonstrated remarkable plasticity in ion channel localization and biophysical properties in epilepsy, many of which produce hyperexcitability and may contribute to the development and maintenance of the epileptic state. Here we review recent advances in dendritic physiology and cell biology, and their relevance to epilepsy. PMID:23216577

  11. Sequence learning in differentially activated dendrites

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2003-01-01

    Differentially activated areas of a dendrite permit the existence of zones with distinct rates of synaptic modification, and such areas can be individually accessed using a reference signal which localizes synaptic plasticity and memory trace retrieval to certain subregions of the dendrite....... It is proposed that the neural machinery required in such a learning/retrieval mechanism could involve the NMDA receptor, in conjunction with the ability of dendrites to maintain differentially activated regions. In particular, it is suggested that such a parcellation of the dendrite allows the neuron...... to participate in multiple sequences, which can be learned without suffering from the 'wash-out' of synaptic efficacy associated with superimposition of training patterns. This is a biologically plausible solution to the stability-plasticity dilemma of learning in neural networks....

  12. Dendritic cells in autoimmune thyroid disease.

    Science.gov (United States)

    Kabel, P J; Voorbij, H A; van der Gaag, R D; Wiersinga, W M; de Haan, M; Drexhage, H A

    1987-01-01

    Dendritic cells form a morphologically distinct class of cells characterized by shape, reniform nucleus, absent to weak acid-phosphatase activity and strong Class II MHC determinant positivity. Functionally they are the most efficient cells in antigen presentation to T-lymphocytes which indicates their role in the initiation of an immune response. Using immunehistochemical techniques we studied the presence of dendritic cells in normal Wistar rat and human thyroids, in thyroids of BBW rats developing thyroid autoimmunity and in Graves' goitres. Dendritic cells could be identified in all thyroids studied and were positioned underneath the thyrocytes in between the follicles. Skin dendritic cells travel via lymphatics to draining lymph nodes, thus forming an antigen presenting cell system. It is likely that a similar cell system exists on the level of the thyroid for dendritic cells have also been detected in thyroid draining lymph nodes. In normal thyroid tissue of both human and rat dendritic cells were relatively scarce. During the initial phases of the thyroid autoimmune response in the BBW rat (before the appearance of Tg-antibodies in the circulation) numbers of thyroid dendritic cells increased. Intrathyroidal T-helper cells, B-cells or plasma cells could not be found. The thyroid draining lymph node contained large numbers of plasma cells. During the later stages of the thyroid autoimmune response in the BB/W rat (after the appearance of Tg-antibodies in the circulation) and in Graves' goitres dendritic cells were not only present in high number, but 20-30% were seen in contact with now-present intrathyroidal T-helper lymphocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Human CD141+ Dendritic Cell and CD1c+ Dendritic Cell Undergo Concordant Early Genetic Programming after Activation in Humanized Mice In Vivo

    Directory of Open Access Journals (Sweden)

    Yoshihito Minoda

    2017-10-01

    Full Text Available Human immune cell subsets develop in immunodeficient mice following reconstitution with human CD34+ hematopoietic stem cells. These “humanized” mice are useful models to study human immunology and human-tropic infections, autoimmunity, and cancer. However, some human immune cell subsets are unable to fully develop or acquire full functional capacity due to a lack of cross-reactivity of many growth factors and cytokines between species. Conventional dendritic cells (cDCs in mice are categorized into cDC1, which mediate T helper (Th1 and CD8+ T cell responses, and cDC2, which mediate Th2 and Th17 responses. The likely human equivalents are CD141+ DC and CD1c+ DC subsets for mouse cDC1 and cDC2, respectively, but the extent of any interspecies differences is poorly characterized. Here, we exploit the fact that human CD141+ DC and CD1c+ DC develop in humanized mice, to further explore their equivalency in vivo. Global transcriptome analysis of CD141+ DC and CD1c+ DC isolated from humanized mice demonstrated that they closely resemble those in human blood. Activation of DC subsets in vivo, with the TLR3 ligand poly I:C, and the TLR7/8 ligand R848 revealed that a core panel of genes consistent with DC maturation status were upregulated by both subsets. R848 specifically upregulated genes associated with Th17 responses by CD1c+ DC, while poly I:C upregulated IFN-λ genes specifically by CD141+ DC. MYCL expression, known to be essential for CD8+ T cell priming by mouse DC, was specifically induced in CD141+ DC after activation. Concomitantly, CD141+ DC were superior to CD1c+ DC in their ability to prime naïve antigen-specific CD8+ T cells. Thus, CD141+ DC and CD1c+ DC share a similar activation profiles in vivo but also have induce unique signatures that support specialized roles in CD8+ T cell priming and Th17 responses, respectively. In combination, these data demonstrate that humanized mice provide an attractive and tractable model to study

  14. Dendritic solidification in undercooled Ni-Zr-Al melts: Experiments and modeling

    Energy Technology Data Exchange (ETDEWEB)

    Galenko, P.K., E-mail: Peter.Galenko@dlr.de [Institut fuer Materialsphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), D-51170 Koeln (Germany); Reutzel, S.; Herlach, D.M. [Institut fuer Materialsphysik im Weltraum, Deutsches Zentrum fuer Luft- und Raumfahrt (DLR), D-51170 Koeln (Germany); Fries, S.G. [ICAMS, Ruhr-Universitaet Bochum, Stiepeler Strasse 129, D-44780 Bochum (Germany)] [SGF Scientific Consultancy, Arndtstr 9, D-52064 Aachen (Germany); Steinbach, I. [ICAMS, Ruhr-Universitaet Bochum, Stiepeler Strasse 129, D-44780 Bochum (Germany); Apel, M. [ACCESS eV, Intzestrasse 5, D-52072 Aachen (Germany)

    2009-12-15

    The kinetics of dendritic solidification in a ternary Ni{sub 98}Zr{sub 1}Al{sub 1} alloy is investigated experimentally in a range of melt undercoolings 40K{<=}{Delta}T{<=}320K. The growth velocity is measured for samples processed by the electromagnetic levitation technique using a high-speed video camera. With {Delta}T{<=}220K the measured growth rates are the same as those of a binary Ni{sub 99}Zr{sub 1} alloy. In the regime of rapid solidification, especially within the regime of thermal dendritic growth at {Delta}T{>=}220K, growth rates are decreased. Sharp-interface modeling predicts growth rates over the whole range of undercooling. Phase-field simulations give quantitative predictions for the dendritic growth velocity in the solute-controlled growth regime. Results show that the composition and temperature dependency of the thermodynamic data, e.g. liquidus slope and solute partition coefficient, are important for describing the alloys. Our findings give improved sharp-interface model predictions compared to calculations based on an approximation of the thermodynamic data derived from binary phase diagrams.

  15. Synaptic Control of Secretory Trafficking in Dendrites

    Directory of Open Access Journals (Sweden)

    Cyril Hanus

    2014-06-01

    Full Text Available Localized signaling in neuronal dendrites requires tight spatial control of membrane composition. Upon initial synthesis, nascent secretory cargo in dendrites exits the endoplasmic reticulum (ER from local zones of ER complexity that are spatially coupled to post-ER compartments. Although newly synthesized membrane proteins can be processed locally, the mechanisms that control the spatial range of secretory cargo transport in dendritic segments are unknown. Here, we monitored the dynamics of nascent membrane proteins in dendritic post-ER compartments under regimes of low or increased neuronal activity. In response to activity blockade, post-ER carriers are highly mobile and are transported over long distances. Conversely, increasing synaptic activity dramatically restricts the spatial scale of post-ER trafficking along dendrites. This activity-induced confinement of secretory cargo requires site-specific phosphorylation of the kinesin motor KIF17 by Ca2+/calmodulin-dependent protein kinases (CaMK. Thus, the length scales of early secretory trafficking in dendrites are tuned by activity-dependent regulation of microtubule-dependent transport.

  16. Somal and dendritic development of human CA3 pyramidal neurons from midgestation to middle childhood: a quantitative Golgi study.

    Science.gov (United States)

    Lu, Dahua; He, Lixin; Xiang, Wei; Ai, Wei-Min; Cao, Ye; Wang, Xiao-Sheng; Pan, Aihua; Luo, Xue-Gang; Li, Zhiyuan; Yan, Xiao-Xin

    2013-01-01

    The CA3 area serves a key relay on the tri-synaptic loop of the hippocampal formation which supports multiple forms of mnemonic processing, especially spatial learning and memory. To date, morphometric data about human CA3 pyramidal neurons are relatively rare, with little information available for their pre- and postnatal development. Herein, we report a set of developmental trajectory data, including somal growth, dendritic elongation and branching, and spine formation, of human CA3 pyramidal neurons from midgestation stage to middle childhood. Golgi-impregnated CA3 pyramidal neurons in fetuses at 19, 20, 26, 35, and 38 weeks of gestation (GW) and a child at 8 years of age (Y) were analyzed by Neurolucida morphometry. Somal size of the impregnated CA3 cells increased age-dependently among the cases. The length of the apical and basal dendrites of these neurons increased between 26 GW to 38 GW, and appeared to remain stable afterward until 8 Y. Dendritic branching points increased from 26 GW to 38 GW, with that on the apical dendrites slightly reduced at 8 Y. Spine density on the apical and basal dendrites increased progressively from 26 GW to 8 Y. These data suggest that somal growth and dendritic arborization of human CA3 pyramidal neurons occur largely during the second to third trimester. Spine development and likely synaptogenesis on CA3 pyramidal cells progress during the third prenatal trimester and may continue throughout childhood. Copyright © 2012 Wiley Periodicals, Inc.

  17. Embryonic origins of a motor system: motor dendrites form a myotopic map in Drosophila.

    Directory of Open Access Journals (Sweden)

    Matthias Landgraf

    2003-11-01

    Full Text Available The organisational principles of locomotor networks are less well understood than those of many sensory systems, where in-growing axon terminals form a central map of peripheral characteristics. Using the neuromuscular system of the Drosophila embryo as a model and retrograde tracing and genetic methods, we have uncovered principles underlying the organisation of the motor system. We find that dendritic arbors of motor neurons, rather than their cell bodies, are partitioned into domains to form a myotopic map, which represents centrally the distribution of body wall muscles peripherally. While muscles are segmental, the myotopic map is parasegmental in organisation. It forms by an active process of dendritic growth independent of the presence of target muscles, proper differentiation of glial cells, or (in its initial partitioning competitive interactions between adjacent dendritic domains. The arrangement of motor neuron dendrites into a myotopic map represents a first layer of organisation in the motor system. This is likely to be mirrored, at least in part, by endings of higher-order neurons from central pattern-generating circuits, which converge onto the motor neuron dendrites. These findings will greatly simplify the task of understanding how a locomotor system is assembled. Our results suggest that the cues that organise the myotopic map may be laid down early in development as the embryo subdivides into parasegmental units.

  18. Recognition of Aspergillus fumigatus hyphae by human plasmacytoid dendritic cells is mediated by dectin-2 and results in formation of extracellular traps.

    Directory of Open Access Journals (Sweden)

    Flávio V Loures

    2015-02-01

    Full Text Available Plasmacytoid dendritic cells (pDCs were initially considered as critical for innate immunity to viruses. However, our group has shown that pDCs bind to and inhibit the growth of Aspergillus fumigatus hyphae and that depletion of pDCs renders mice hypersusceptible to experimental aspergillosis. In this study, we examined pDC receptors contributing to hyphal recognition and downstream events in pDCs stimulated by A. fumigatus hyphae. Our data show that Dectin-2, but not Dectin-1, participates in A. fumigatus hyphal recognition, TNF-α and IFN-α release, and antifungal activity. Moreover, Dectin-2 acts in cooperation with the FcRγ chain to trigger signaling responses. In addition, using confocal and electron microscopy we demonstrated that the interaction between pDCs and A. fumigatus induced the formation of pDC extracellular traps (pETs containing DNA and citrullinated histone H3. These structures closely resembled those of neutrophil extracellular traps (NETs. The microarray analysis of the pDC transcriptome upon A. fumigatus infection also demonstrated up-regulated expression of genes associated with apoptosis as well as type I interferon-induced genes. Thus, human pDCs directly recognize A. fumigatus hyphae via Dectin-2; this interaction results in cytokine release and antifungal activity. Moreover, hyphal stimulation of pDCs triggers a distinct pattern of pDC gene expression and leads to pET formation.

  19. Lymphoid Aggregates That Resemble Tertiary Lymphoid Organs Define a Specific Pathological Subset in Metal-on-Metal Hip Replacements

    Science.gov (United States)

    Barone, Francesca; Hardie, Debbie L.; Matharu, Gulraj S.; Davenport, Alison J.; Martin, Richard A.; Grant, Melissa; Mosselmans, Frederick; Pynsent, Paul; Sumathi, Vaiyapuri P.; Addison, Owen; Revell, Peter A.; Buckley, Christopher D.

    2013-01-01

    Aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL) has been used to describe the histological lesion associated with metal-on-metal (M-M) bearings. We tested the hypothesis that the lymphoid aggregates, associated with ALVAL lesions resemble tertiary lymphoid organs (TLOs). Histopathological changes were examined in the periprosthetic tissue of 62 M-M hip replacements requiring revision surgery, with particular emphasis on the characteristics and pattern of the lymphocytic infiltrate. Immunofluorescence and immunohistochemistry were used to study the classical features of TLOs in cases where large organized lymphoid follicles were present. Synchrotron X-ray fluorescence (XRF) measurements were undertaken to detect localisation of implant derived ions/particles within the samples. Based on type of lymphocytic infiltrates, three different categories were recognised; diffuse aggregates (51%), T cell aggregates (20%), and organised lymphoid aggregates (29%). Further investigation of tissues with organised lymphoid aggregates showed that these tissues recapitulate many of the features of TLOs with T cells and B cells organised into discrete areas, the presence of follicular dendritic cells, acquisition of high endothelial venule like phenotype by blood vessels, expression of lymphoid chemokines and the presence of plasma cells. Co-localisation of implant-derived metals with lymphoid aggregates was observed. These findings suggest that in addition to the well described general foreign body reaction mediated by macrophages and a T cell mediated type IV hypersensitivity response, an under-recognized immunological reaction to metal wear debris involving B cells and the formation of tertiary lymphoid organs occurs in a distinct subset of patients with M-M implants. PMID:23723985

  20. Nonuniform alteration of dendritic development in the cerebral cortex following prenatal cocaine exposure.

    Science.gov (United States)

    Jones, L; Fischer, I; Levitt, P

    1996-01-01

    reached a nadir of 50% in the cocaine-exposed animals, indicative of a change in the organization of the apical dendrites compared to the control animals. Dendritic profiles of anterior cingulate neurons, filled by 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine percholate (Dil), confirmed that in the cocaine offspring, the dendrites coursed in an irregular, wavy manner from deep to superficial layers, suggestive of dendrites that were longer than normal, although cortical thickness was unchanged. The altered dendritic profiles also were seen in Golgi-impregnated neurons. The data indicate that prenatal exposure to cocaine can lead to specific alterations of neuronal growth that are long lasting. The lack of dendritic changes in visual cortex suggests that the drug does not modify development of cortical regions uniformly. This study also provides a new focus on the anterior cingulate cortex as a site in which aberrant structure-function relationships following prenatal cocaine exposure should be examined in both animal models and clinically.

  1. Dendritic cell-based immunotherapy.

    Science.gov (United States)

    Osada, Takuya; Clay, Timothy M; Woo, Christopher Y; Morse, Michael A; Lyerly, H Kim

    2006-01-01

    Dendritic cells (DCs) play a crucial role in the induction of antigen-specific T-cell responses, and therefore their use for the active immunotherapy of malignancies has been studied with considerable interest. More than a decade has passed since the publication of the first clinical data of DC-based vaccines, and through this and subsequent studies, a number of important developmental insights have been gleaned. These include the ideal source and type of DCs, the discovery of novel antigens and methods of loading DCs, the role of DC maturation, and the most efficient route of immunization. The generation of immune responses against tumor antigens after DC immunization has been demonstrated, and favorable clinical responses have been reported in some patients; however, it is difficult to pool the results as a whole, and thus the body of data remains inconclusive, in part because of varying DC preparation and vaccination protocols, the use of different forms of antigens, and, most importantly, a lack of rigorous criteria for defining clinical responses. As such, the standardization of clinical and immunologic criteria utilized, as well as DC preparations employed, will allow for the comparison of results across multiple clinical studies and is required in order for future trials to measure the true value and role of this treatment modality. In addition, issues regarding the optimal dose and clinical setting for the application of DC vaccines remain to be resolved, and recent clinical studies have been designed to begin to address these questions.

  2. Lipopolysaccharide-induced expression of TRAIL promotes dendritic cell differentiation.

    Science.gov (United States)

    Cho, Young S; Challa, Sreerupa; Clancy, Lauren; Chan, Francis K-M

    2010-08-01

    Tumour necrosis factor-related apoptosis inducing ligand (TRAIL) is a death-inducing cytokine whose physiological function is not well understood. Here, we show that TRAIL has a role in programming human dendritic cell (DC) differentiation. TRAIL expression was strongly induced in DCs upon stimulation with lipopolysaccharide (LPS) or Polyinosine-polycytidylic acid (poly(I:C)) stimulation. Blockade of TRAIL with neutralizing antibody partially inhibited LPS-induced up-regulation of co-stimulatory molecules and the expression of inflammatory cytokines including interleukin-12 (IL-12) p70. In addition, neutralization of TRAIL in LPS-treated DCs inhibited the DC-driven differentiation of T cells into interferon-gamma (IFN-gamma) -producing effectors. The effects of TRAIL neutralization in poly(I:C)-treated DCs were similar, except that IL-12 production and the differentiation of effector T cells into IFN-gamma producers were not inhibited. Strikingly, TRAIL stimulation alone was sufficient to induce morphological changes resembling DC maturation, up-regulation of co-stimulatory molecules, and enhancement of DC-driven allogeneic T-cell proliferation. However, TRAIL alone did not induce inflammatory cytokine production. We further show that the effects of TRAIL on DC maturation were not the result of the induction of apoptosis, but may involve p38 activation. Hence, our data demonstrate that TRAIL co-operates with other cytokines to facilitate DC functional maturation in response to Toll-like receptor activation.

  3. [Clustering analysis of karyotype resemblance-near coefficient for 6 Bupleurum species].

    Science.gov (United States)

    Song, Yun; Qiao, Yonggang; Wu, Yuxiang

    2012-04-01

    To explore the genetic evolutionary distance between plants by using karyotype parameters identification of medicinal plants. The cluster analysis of karyotype resemblance-near coefficient and evolutionary distance was used for 6 Bupleurum species. The results showed that there were the biggest karyotype resemblance-near coefficient (0.9920) and the smallest evolutionary distance (D(e) = 0.0080) between B. scorzonerifolium and B. chinense, indicating the closest relationship, and the minimum karyotype resemblance-near coefficient (0.4794) and the maximum evolutionary distance (D(e) = 0.7352) between B. smityii and B. falcatum, indicating the most distant relationship. Karyotype was an important parameter for identification of medicinal plants because karyotype was stabilized for species. The genetic distance between in 6 species of Bupleurum species was obtained by karyotype clustering analysis of karyotype resemblance-near coefficient. There was the bigger evolutionary distance between the species which had different chromosome number.

  4. The effects of early-life seizures on hippocampal dendrite development and later-life learning and memory.

    Science.gov (United States)

    Casanova, J R; Nishimura, Masataka; Swann, John W

    2014-04-01

    Severe childhood epilepsy is commonly associated with intellectual developmental disabilities. The reasons for these cognitive deficits are likely multifactorial and will vary between epilepsy syndromes and even among children with the same syndrome. However, one factor these children have in common is the recurring seizures they experience - sometimes on a daily basis. Supporting the idea that the seizures themselves can contribute to intellectual disabilities are laboratory results demonstrating spatial learning and memory deficits in normal mice and rats that have experienced recurrent seizures in infancy. Studies reviewed here have shown that seizures in vivo and electrographic seizure activity in vitro both suppress the growth of hippocampal pyramidal cell dendrites. A simplification of dendritic arborization and a resulting decrease in the number and/or properties of the excitatory synapses on them could help explain the observed cognitive disabilities. There are a wide variety of candidate mechanisms that could be involved in seizure-induced growth suppression. The challenge is designing experiments that will help focus research on a limited number of potential molecular events. Thus far, results suggest that growth suppression is NMDA receptor-dependent and associated with a decrease in activation of the transcription factor CREB. The latter result is intriguing since CREB is known to play an important role in dendrite growth. Seizure-induced dendrite growth suppression may not occur as a single process in which pyramidal cells dendrites simply stop growing or grow slower compared to normal neurons. Instead, recent results suggest that after only a few hours of synchronized epileptiform activity in vitro dendrites appear to partially retract. This acute response is also NMDA receptor dependent and appears to be mediated by the Ca(+2)/calmodulin-dependent phosphatase, calcineurin. An understanding of the staging of seizure-induced growth suppression and the

  5. Different roles of the small GTPases Rac1, Cdc42, and RhoG in CALEB/NGC-induced dendritic tree complexity.

    Science.gov (United States)

    Schulz, Jana; Franke, Kristin; Frick, Manfred; Schumacher, Stefan

    2016-10-01

    Rho GTPases play prominent roles in the regulation of cytoskeletal reorganization. Many aspects have been elaborated concerning the individual functions of Rho GTPases in distinct signaling pathways leading to cytoskeletal rearrangements. However, major questions have yet to be answered regarding the integration and the signaling hierarchy of different Rho GTPases in regulating the cytoskeleton in fundamental physiological events like neuronal process differentiation. Here, we investigate the roles of the small GTPases Rac1, Cdc42, and RhoG in defining dendritic tree complexity stimulated by the transmembrane epidermal growth factor family member CALEB/NGC. Combining gain-of-function and loss-of-function analysis in primary hippocampal neurons, we find that Rac1 is essential for CALEB/NGC-mediated dendritic branching. Cdc42 reduces the complexity of dendritic trees. Interestingly, we identify the palmitoylated isoform of Cdc42 to adversely affect dendritic outgrowth and dendritic branching, whereas the prenylated Cdc42 isoform does not. In contrast to Rac1, CALEB/NGC and Cdc42 are not directly interconnected in regulating dendritic tree complexity. Unlike Rac1, the Rac1-related GTPase RhoG reduces the complexity of dendritic trees by acting upstream of CALEB/NGC. Mechanistically, CALEB/NGC activates Rac1, and RhoG reduces the amount of CALEB/NGC that is located at the right site for Rac1 activation at the cell membrane. Thus, Rac1, Cdc42, and RhoG perform very specific and non-redundant functions at different levels of hierarchy in regulating dendritic tree complexity induced by CALEB/NGC. Rho GTPases play a prominent role in dendritic branching. CALEB/NGC is a transmembrane member of the epidermal growth factor (EGF) family that mediates dendritic branching, dependent on Rac1. CALEB/NGC stimulates Rac1 activity. RhoG inhibits CALEB/NGC-mediated dendritic branching by decreasing the amount of CALEB/NGC at the plasma membrane. Palmitoylated, but not prenylated form

  6. A synthetic NOD2 agonist, muramyl dipeptide (MDP)-Lys (L18) and IFN-β synergistically induce dendritic cell maturation with augmented IL-12 production and suppress melanoma growth.

    Science.gov (United States)

    Fujimura, Taku; Yamasaki, Kenshi; Hidaka, Takanori; Ito, Yumiko; Aiba, Setsuya

    2011-05-01

    A synthetic NOD2 agonist, muramyl dipeptide (MDP)-Lys (L18), mimics the bacterial peptidoglycan moiety and acts as a powerful adjuvant that induces cell-mediated immunity. To investigate the induction of antitumor immune response for malignant melanoma by IFN-β in combination with MDP-Lys (L18) (IFN-MDP-Lys (L18)). Human monocyte-derived DCs (MoDCs) are stimulated with IFN-MDP-Lys (L18) in vitro. We assess the expression of costimulatory molecules on MoDCs by FACS. Moreover, we investigate the induction of Th1 cytokines by real time PCR and ELISA. Further to confirm the anti tumor immune response of IFN-MDP-Lys (L18) therapy, we examine the growth of B16F10 melanoma in vivo. The stimulation of human MoDCs with IFN-MDP-Lys (L18) significantly augmented the production of IL-12p70, TNF-α, and IL-6 compared to that with MDP or that with IFN-β alone. IFN-MDP-Lys (L18) increased the expression of IL-12p35, IL-12p40, IL-10, TNF-α, IL-6 and IL-1β mRNA by MoDC using real-time PCR. The expression of CD83 and costimulatory molecules CD40, CD80, and CD86 was also augmented in MoDC treated with IFN-MDP-Lys (L18), which resulted in their augmented allogeneic T cell stimulation. In vivo, the administration of IFN-MDP-Lys (L18) significantly suppressed the growth of B16F10 melanoma, while the monotherapy of IFN-β or MDP-Lys (L18) did not significantly affect the tumor growth. These findings suggest that IFN-MDP-Lys (L18) can be a promising adjuvant therapy for malignant melanoma. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  7. Self-referential forces are sufficient to explain different dendritic morphologies

    Science.gov (United States)

    Memelli, Heraldo; Torben-Nielsen, Benjamin; Kozloski, James

    2013-01-01

    Dendritic morphology constrains brain activity, as it determines first which neuronal circuits are possible and second which dendritic computations can be performed over a neuron's inputs. It is known that a range of chemical cues can influence the final shape of dendrites during development. Here, we investigate the extent to which self-referential influences, cues generated by the neuron itself, might influence morphology. To this end, we developed a phenomenological model and algorithm to generate virtual morphologies, which are then compared to experimentally reconstructed morphologies. In the model, branching probability follows a Galton–Watson process, while the geometry is determined by “homotypic forces” exerting influence on the direction of random growth in a constrained space. We model three such homotypic forces, namely an inertial force based on membrane stiffness, a soma-oriented tropism, and a force of self-avoidance, as directional biases in the growth algorithm. With computer simulations we explored how each bias shapes neuronal morphologies. We show that based on these principles, we can generate realistic morphologies of several distinct neuronal types. We discuss the extent to which homotypic forces might influence real dendritic morphologies, and speculate about the influence of other environmental cues on neuronal shape and circuitry. PMID:23386828

  8. Self-referential forces are sufficient to explain different dendritic morphologies

    Directory of Open Access Journals (Sweden)

    Heraldo eMemelli

    2013-01-01

    Full Text Available Dendritic morphology constrains brain activity, as it determines first which neuronal circuits are possible and second which dendritic computations can be performed over a neuron's inputs. It is known that a range of chemical cues can influence the final shape of dendrites during development. Here, we investigate the extent to which self-referential influences, cues generated by the neuron itself, might influence morphology. To this end, we developed a phenomenological model and algorithm to generate virtual morphologies, which are then compared to experimentally reconstructed morphologies. In the model, branching probability follows a Galton-Watson process, while the geometry is determined by "homotypic forces" exerting influence on the direction of random growth in a constrained space. We model three such homotypic forces, namely an inertial force based on membrane stiffness, a soma-oriented tropism, and a force of self avoidance, as directional biases in the growth algorithm. With computer simulations we explored how each bias shapes neuronal morphologies. We show that based on these principles, we can generate realistic morphologies of several distinct neuronal types. We discuss the extent to which homotypic forces might influence real dendritic morphologies, and speculate about the influence of other environmental cues on neuronal shape and circuitry.

  9. A bifunctional electrolyte additive for separator wetting and dendrite suppression in lithium metal batteries

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Hao; Xie, Yong; Xiang, Hongfa; Shi, Pengcheng; Liang, Xin; Xu, Wu

    2018-04-01

    Reformulation of electrolyte systems and improvement of separator wettability are vital to electrochemical performances of rechargeable lithium (Li) metal batteries, especially for suppressing Li dendrites. In this work we report a bifunctional electrolyte additive that improves separator wettability and suppresses Li dendrite growth in LMBs. A triblock polyether (Pluronic P123) was introduced as an additive into a commonly used carbonate-based electrolyte. It was found that addition of 0.2~1% (by weight) P123 into the electrolyte could effectively enhance the wettability of polyethylene separator. More importantly, the adsorption of P123 on Li metal surface can act as an artificial solid electrolyte interphase layer and contribute to suppress the growth of Li dendrites. A smooth and dendritic-free morphology can be achieved in the electrolyte with 0.2% P123. The Li||Li symmetric cells with the 0.2% P123 containing electrolyte exhibit a relatively stable cycling stability at high current densities of 1.0 and 3.0 mA cm-2.

  10. Emerging Roles of Filopodia and Dendritic Spines in Motoneuron Plasticity during Development and Disease

    Directory of Open Access Journals (Sweden)

    Refik Kanjhan

    2016-01-01

    Full Text Available Motoneurons develop extensive dendritic trees for receiving excitatory and inhibitory synaptic inputs to perform a variety of complex motor tasks. At birth, the somatodendritic domains of mouse hypoglossal and lumbar motoneurons have dense filopodia and spines. Consistent with Vaughn’s synaptotropic hypothesis, we propose a developmental unified-hybrid model implicating filopodia in motoneuron spinogenesis/synaptogenesis and dendritic growth and branching critical for circuit formation and synaptic plasticity at embryonic/prenatal/neonatal period. Filopodia density decreases and spine density initially increases until postnatal day 15 (P15 and then decreases by P30. Spine distribution shifts towards the distal dendrites, and spines become shorter (stubby, coinciding with decreases in frequency and increases in amplitude of excitatory postsynaptic currents with maturation. In transgenic mice, either overexpressing the mutated human Cu/Zn-superoxide dismutase (hSOD1G93A gene or deficient in GABAergic/glycinergic synaptic transmission (gephyrin, GAD-67, or VGAT gene knockout, hypoglossal motoneurons develop excitatory glutamatergic synaptic hyperactivity. Functional synaptic hyperactivity is associated with increased dendritic growth, branching, and increased spine and filopodia density, involving actin-based cytoskeletal and structural remodelling. Energy-dependent ionic pumps that maintain intracellular sodium/calcium homeostasis are chronically challenged by activity and selectively overwhelmed by hyperactivity which eventually causes sustained membrane depolarization leading to excitotoxicity, activating microglia to phagocytose degenerating neurons under neuropathological conditions.

  11. Daam1a mediates asymmetric habenular morphogenesis by regulating dendritic and axonal outgrowth

    Science.gov (United States)

    Colombo, Alicia; Palma, Karina; Armijo, Lorena; Mione, Marina; Signore, Iskra A.; Morales, Camila; Guerrero, Néstor; Meynard, Margarita M.; Pérez, Ramón; Suazo, José; Marcelain, Katherine; Briones, Luis; Härtel, Steffen; Wilson, Stephen W.; Concha, Miguel L.

    2013-01-01

    Although progress has been made in resolving the genetic pathways that specify neuronal asymmetries in the brain, little is known about genes that mediate the development of structural asymmetries between neurons on left and right. In this study, we identify daam1a as an asymmetric component of the signalling pathways leading to asymmetric morphogenesis of the habenulae in zebrafish. Daam1a is a member of the Formin family of actin-binding proteins and the extent of Daam1a expression in habenular neuron dendrites mirrors the asymmetric growth of habenular neuropil between left and right. Local loss and gain of Daam1a function affects neither cell number nor subtype organisation but leads to a decrease or increase of neuropil, respectively. Daam1a therefore plays a key role in the asymmetric growth of habenular neuropil downstream of the pathways that specify asymmetric cellular domains in the habenulae. In addition, Daam1a mediates the development of habenular efferent connectivity as local loss and gain of Daam1a function impairs or enhances, respectively, the growth of habenular neuron terminals in the interpeduncular nucleus. Abrogation of Daam1a disrupts the growth of both dendritic and axonal processes and results in disorganised filamentous actin and α-tubulin. Our results indicate that Daam1a plays a key role in asymmetric habenular morphogenesis mediating the growth of dendritic and axonal processes in dorsal habenular neurons. PMID:24046318

  12. Neurotrophin-mediated dendrite-to-nucleus signaling revealed by microfluidic compartmentalization of dendrites.

    Science.gov (United States)

    Cohen, Michael S; Bas Orth, Carlos; Kim, Hyung Joon; Jeon, Noo Li; Jaffrey, Samie R

    2011-07-05

    Signaling from dendritic synapses to the nucleus regulates important aspects of neuronal function, including synaptic plasticity. The neurotrophin brain-derived neurotrophic factor (BDNF) can induce long-lasting strengthening of synapses in vivo and this effect is dependent on transcription. However, the mechanism of signaling to the nucleus is not well understood. Here we describe a microfluidic culture device to investigate dendrite-to-nucleus signaling. Using these microfluidic devices, we demonstrate that BDNF can act directly on dendrites to elicit an anterograde signal that induces transcription of the immediate early genes, Arc and c-Fos. Induction of Arc is dependent on dendrite- and cell body-derived calcium, whereas induction of c-Fos is calcium-independent. In contrast to retrograde neurotrophin-mediated axon-to-nucleus signaling, which is MEK5-dependent, BDNF-mediated anterograde dendrite-to-nucleus signaling is dependent on MEK1/2. Intriguingly, the activity of TrkB, the BDNF receptor, is required in the cell body for the induction of Arc and c-Fos mediated by dendritically applied BDNF. These results are consistent with the involvement of a signaling endosome-like pathway that conveys BDNF signals from the dendrite to the nucleus.

  13. Preparation of dendritic Ag/Au bimetallic nanostructures and their application in surface-enhanced Raman scattering

    International Nuclear Information System (INIS)

    Yi Zao; Chen Shanjun; Chen Yan; Luo Jiangshan; Wu Weidong; Yi Yougen; Tang Yongjian

    2012-01-01

    Dendritic Ag/Au bimetallic nanostructures have been synthesized via a multi-stage galvanic replacement reaction of Ag dendrites in a chlorauric acid (HAuCl 4 ) solution at room temperature. After five stages of replacement reaction, one obtains structures with protruding nanocubes; these will mature into many porous structures with a few Ag atoms that are left over dendrites. The morphological and compositional changes which evolved with reaction stages were analyzed by using scanning electron microscopy, transmission electron microscopy, UV–visible spectroscopy, selected area electron diffraction and energy-dispersive X-ray spectrometry. The replacement of Ag with Au was confirmed. A formation mechanism involving the original development of Ag dendrites into porous structures with the growth of Au nanocubes on this underlying structure as the number of reaction stages is proposed. This was confirmed by surface-enhanced Raman scattering (SERS). The dendritic Ag/Au bimetallic nanostructures could be used as efficient SERS active substrates. It was found that the SERS enhancement ability was dependent on the stage of galvanic replacement reaction. - Highlights: ► Dendritic Ag/Au bimetallic nanostructures have been synthesized. ► Protruding cubic nanostructures obtained after 5 stages mature into porous structures. ► SERS results allow confirm the proposed formation mechanism. ► The nanostructures could be used as efficient SERS active substrates.

  14. Sequence learning in differentially activated dendrites

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2003-01-01

    to participate in multiple sequences, which can be learned without suffering from the 'wash-out' of synaptic efficacy associated with superimposition of training patterns. This is a biologically plausible solution to the stability-plasticity dilemma of learning in neural networks........ It is proposed that the neural machinery required in such a learning/retrieval mechanism could involve the NMDA receptor, in conjunction with the ability of dendrites to maintain differentially activated regions. In particular, it is suggested that such a parcellation of the dendrite allows the neuron...

  15. Regeneration of Drosophila sensory neuron axons and dendrites is regulated by the Akt pathway involving Pten and microRNA bantam

    Science.gov (United States)

    Song, Yuanquan; Ori-McKenney, Kassandra M.; Zheng, Yi; Han, Chun; Jan, Lily Yeh; Jan, Yuh Nung

    2012-01-01

    Both cell-intrinsic and extrinsic pathways govern axon regeneration, but only a limited number of factors have been identified and it is not clear to what extent axon regeneration is evolutionarily conserved. Whether dendrites also regenerate is unknown. Here we report that, like the axons of mammalian sensory neurons, the axons of certain Drosophila dendritic arborization (da) neurons are capable of substantial regeneration in the periphery but not in the CNS, and activating the Akt pathway enhances axon regeneration in the CNS. Moreover, those da neurons capable of axon regeneration also display dendrite regeneration, which is cell type-specific, developmentally regulated, and associated with microtubule polarity reversal. Dendrite regeneration is restrained via inhibition of the Akt pathway in da neurons by the epithelial cell-derived microRNA bantam but is facilitated by cell-autonomous activation of the Akt pathway. Our study begins to reveal mechanisms for dendrite regeneration, which depends on both extrinsic and intrinsic factors, including the PTEN–Akt pathway that is also important for axon regeneration. We thus established an important new model system—the fly da neuron regeneration model that resembles the mammalian injury model—with which to study and gain novel insights into the regeneration machinery. PMID:22759636

  16. Amyloid plaque formation precedes dendritic spine loss.

    Science.gov (United States)

    Bittner, Tobias; Burgold, Steffen; Dorostkar, Mario M; Fuhrmann, Martin; Wegenast-Braun, Bettina M; Schmidt, Boris; Kretzschmar, Hans; Herms, Jochen

    2012-12-01

    Amyloid-beta plaque deposition represents a major neuropathological hallmark of Alzheimer's disease. While numerous studies have described dendritic spine loss in proximity to plaques, much less is known about the kinetics of these processes. In particular, the question as to whether synapse loss precedes or follows plaque formation remains unanswered. To address this question, and to learn more about the underlying kinetics, we simultaneously imaged amyloid plaque deposition and dendritic spine loss by applying two-photon in vivo microscopy through a cranial window in double transgenic APPPS1 mice. As a result, we first observed that the rate of dendritic spine loss in proximity to plaques is the same in both young and aged animals. However, plaque size only increased significantly in the young cohort, indicating that spine loss persists even many months after initial plaque appearance. Tracking the fate of individual spines revealed that net spine loss is caused by increased spine elimination, with the rate of spine formation remaining constant. Imaging of dendritic spines before and during plaque formation demonstrated that spine loss around plaques commences at least 4 weeks after initial plaque formation. In conclusion, spine loss occurs, shortly but with a significant time delay, after the birth of new plaques, and persists in the vicinity of amyloid plaques over many months. These findings hence give further hope to the possibility that there is a therapeutic window between initial amyloid plaque deposition and the onset of structural damage at spines.

  17. Molecular characterization of interdigitating dendritic cell sarcoma

    Directory of Open Access Journals (Sweden)

    Glen J. Weiss

    2010-08-01

    Full Text Available Interdigitating dendritic cell sarcoma is an extremely rare cancer that lacks a standard treatment approach. We report on a patient who was surgically resected and remains disease-free. The tumor was assessed for druggable targets using immunohistochemical staining to identify potential agents that could be used in the event of disease recurrence.

  18. Maximizing dendritic cell migration in cancer immunotherapy

    NARCIS (Netherlands)

    Verdijk, Pauline; Aarntzen, Erik H. J. G.; Punt, Cornelis J. A.; de Vries, I. Jolanda M.; Figdor, Carl G.

    2008-01-01

    The success of dendritic cell (DC)-based immunotherapy in inducing cellular immunity against tumors is highly dependent on accurate delivery and trafficking of the DC to T-cell-rich areas of secondary lymphoid tissues. To provide an overview of DC migration in vivo and how migration to peripheral

  19. Maximizing dendritic cell migration in cancer immunotherapy.

    NARCIS (Netherlands)

    Verdijk, P.; Aarntzen, E.H.J.G.; Punt, C.J.A.; Vries, I.J.M. de; Figdor, C.G.

    2008-01-01

    BACKGROUND: The success of dendritic cell (DC)-based immunotherapy in inducing cellular immunity against tumors is highly dependent on accurate delivery and trafficking of the DC to T-cell-rich areas of secondary lymphoid tissues. OBJECTIVE: To provide an overview of DC migration in vivo and how

  20. Antigen dynamics of follicular dendritic cells

    NARCIS (Netherlands)

    Heesters, B.A.

    2015-01-01

    Stromal-derived follicular dendritic cells (FDCs) are a major depot for antigen that are essential for formation of germinal centers, the site where memory and effector B cells differentiate and high-affinity antibody production takes place. Historically, FDCs have been characterized as ‘accessory’

  1. Characterization of chicken dendritic cell markers

    Science.gov (United States)

    Animal and Natural Resources Institute, ARS-USDA, Beltsville, MD, USA. New mouse monoclonal antibodies which detect CD80 and CD83 were developed to characterize chicken dendritic cells (DCs). The characteristics of these molecules have been studied in human, swine, ovine, feline, and canine but not ...

  2. Ins and outs of dendritic cells.

    NARCIS (Netherlands)

    Schuurhuis, D.H.; Fu, N.; Ossendorp, F.; Melief, C.J.

    2006-01-01

    Dendritic cells (DC) are professional antigen-presenting cells which are strategically positioned at the boundaries between the inner and the outside world, in this way bridging innate and adaptive immunity. DC can initiate T cell responses against microbial pathogens and tumors due to their

  3. Targeting nanoparticles to dendritic cells for immunotherapy.

    NARCIS (Netherlands)

    Cruz, L.J.; Tacken, P.J.; Rueda, F.; Domingo, J.C.; Albericio, F.; Figdor, C.G.

    2012-01-01

    Dendritic cells (DCs) are key players in the initiation of adaptive immune responses and are currently exploited in immunotherapy for treatment of cancer and infectious diseases. Development of targeted nanodelivery systems carrying vaccine components, including antigens and adjuvants, to DCs in

  4. MRI findings of uterine tumor resembling ovarian sex-cord tumor: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung Hwan; Kim, Hee Jin; Han, Hyun Young; Hwang, In Taek; Kim, Ju Heon; Lee, Seung Yeon [Eulji University Hospital, Eulji University School of Medicine, Daejeon (Korea, Republic of)

    2017-04-15

    Uterine tumor resembling ovarian sex-cord tumor is a very rare uterine neoplasm that was first described by Clement and Scully in 1976. Since then, approximately 70 cases have been reported. However, these case reports have mainly described and discussed the pathologic and clinical features, and few radiologic findings have been presented. We experienced a case of a uterine tumor resembling ovarian sex-cord tumor, which was considered a uterine leiomyoma or leiomyosarcoma upon initial impression at preoperative evaluation including transvaginal ultrasonography and pelvic magnetic resonance imaging. Its diagnosis was pathologically confirmed after total abdominal hysterectomy.

  5. Primary Dendrite Arm Spacings in Al-7Si Alloy Directionally Solidified on the International Space Station

    Science.gov (United States)

    Angart, Samuel; Lauer, Mark; Poirier, David; Tewari, Surendra; Rajamure, Ravi; Grugel, Richard

    2015-01-01

    Samples from directionally solidified Al- 7 wt. % Si have been analyzed for primary dendrite arm spacing (lambda) and radial macrosegregation. The alloy was directionally solidified (DS) aboard the ISS to determine the effect of mitigating convection on lambda and macrosegregation. Samples from terrestrial DS-experiments thermal histories are discussed for comparison. In some experiments, lambda was measured in microstructures that developed during the transition from one speed to another. To represent DS in the presence of no convection, the Hunt-Lu model was used to represent diffusion controlled growth under steady-state conditions. By sectioning cross-sections throughout the entire length of a solidified sample, lambda was measured and calculated using the model. During steady-state, there was reasonable agreement between the measured and calculated lambda's in the space-grown samples. In terrestrial samples, the differences between measured and calculated lambda's indicated that the dendritic growth was influenced by convection.

  6. Mechanisms of Dendritic Cell Lysosomal Killing of Cryptococcus

    Science.gov (United States)

    Hole, Camaron R.; Bui, Hoang; Wormley, Floyd L.; Wozniak, Karen L.

    2012-10-01

    Cryptococcus neoformans is an opportunistic pulmonary fungal pathogen that disseminates to the CNS causing fatal meningitis in immunocompromised patients. Dendritic cells (DCs) phagocytose C. neoformans following inhalation. Following uptake, cryptococci translocate to the DC lysosomal compartment and are killed by oxidative and non-oxidative mechanisms. DC lysosomal extracts kill cryptococci in vitro; however, the means of antifungal activity remain unknown. Our studies determined non-oxidative antifungal activity by DC lysosomal extract. We examined DC lysosomal killing of cryptococcal strains, anti-fungal activity of purified lysosomal enzymes, and mechanisms of killing against C. neoformans. Results confirmed DC lysosome fungicidal activity against all cryptococcal serotypes. Purified lysosomal enzymes, specifically cathepsin B, inhibited cryptococcal growth. Interestingly, cathepsin B combined with its enzymatic inhibitors led to enhanced cryptococcal killing. Electron microscopy revealed structural changes and ruptured cryptococcal cell walls following treatment. Finally, additional studies demonstrated that osmotic lysis was responsible for cryptococcal death.

  7. A multi-protein receptor-ligand complex underlies combinatorial dendrite guidance choices in C. elegans

    Science.gov (United States)

    Zou, Wei; Shen, Ao; Dong, Xintong; Tugizova, Madina; Xiang, Yang K; Shen, Kang

    2016-01-01

    Ligand receptor interactions instruct axon guidance during development. How dendrites are guided to specific targets is less understood. The C. elegans PVD sensory neuron innervates muscle-skin interface with its elaborate dendritic branches. Here, we found that LECT-2, the ortholog of leukocyte cell-derived chemotaxin-2 (LECT2), is secreted from the muscles and required for muscle innervation by PVD. Mosaic analyses showed that LECT-2 acted locally to guide the growth of terminal branches. Ectopic expression of LECT-2 from seam cells is sufficient to redirect the PVD dendrites onto seam cells. LECT-2 functions in a multi-protein receptor-ligand complex that also contains two transmembrane ligands on the skin, SAX-7/L1CAM and MNR-1, and the neuronal transmembrane receptor DMA-1. LECT-2 greatly enhances the binding between SAX-7, MNR-1 and DMA-1. The activation of DMA-1 strictly requires all three ligands, which establishes a combinatorial code to precisely target and pattern dendritic arbors. DOI: http://dx.doi.org/10.7554/eLife.18345.001 PMID:27705746

  8. Schwannoma of the Lower Eyelid Resembling a Recurrent Chalazion : A Case Report

    OpenAIRE

    Fukuyama, Junichiro; Hayasaka, Seiji; Setogawa, Tomoichi

    1990-01-01

    A 55-year-old man complained of foreign body sensation and a solid mass in the lower eyelid of the right eye. Clinically, the lesion resembled a chalazion, and it was excised. Histopathologic examination of the excised specimen revealed a schwannoma (neurilemmoma). We believe that this is a rare case of a schwannoma of the lower eyelid simulating a chalazion.

  9. Family resemblance in fat intake, nutrition attitudes and beliefs : a study among three generations of women

    NARCIS (Netherlands)

    Stafleu, A.

    1994-01-01

    In this thesis nutrition attitudes, beliefs, and fat intake in three generations of women are described. The aim of the study was twofold: the development of methods, and to study family resemblance in food habits. Based on literature study and qualitative pilot studies a questionnaire on

  10. Resemblances of Parents and Twins in Sport Participation and Heart Rate

    NARCIS (Netherlands)

    Boomsma, D.I.; van den Bree, M.B.; Orlebeke, J.F.; Molenaar, P.C.M.

    1989-01-01

    A model to analyze resemblances of twins and parents using LISREL is outlined and applied to sports participation and heart-rate data. Sports participation and heart rate were measured in 44 monozygotic and 46 dizygotic adolescent twin pairs and in their parents. Genetic factors influence variation

  11. Startle eye-blink modulation by facial self-resemblance and current mood.

    Science.gov (United States)

    Finke, Johannes B; Larra, Mauro F; Schilling, Thomas M; Lass-Hennemann, Johanna; Blumenthal, Terry D; Schächinger, Hartmut

    2015-06-01

    Although salient stimuli are known to modulate startle eye-blink responses, and one's own face is considered of particular salience, effects of facial self-resemblance on startle responsiveness have not been systematically investigated. For the present study, pictures from the FACES database (rated as neutral) were digitally morphed to resemble the participants' (N=37) faces to varying degrees (25-50-75%). Perceptually matched geometrical shapes served as a control condition. At SOAs of either 300ms or 3000ms after picture onset, startle responses were elicited by white noise (50ms, 105dB), and recorded at the orbicularis oculi via EMG. Prior to the experiment, self-reported mood was assessed by means of the PANAS. Relative to non-face stimuli, the presentation of faces reduced startle magnitude at short, but not long, lead intervals. Furthermore, for probes presented at a SOA of 300ms, a linear decrease in startle magnitude with higher levels of self-resemblance was observed, presumably reflecting higher salience of the self-face. The startle modulating effect of self-resembling faces during longer lead intervals was moderated by the participants' current mood: negative affect predicted stronger patterns of attenuation, which might be interpreted as an increase in self-focus resulting from more negative mood. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Familial neurofibromatosis type 1 associated with an overgrowth syndrome resembling Weaver syndrome

    NARCIS (Netherlands)

    van Asperen, C. J.; Overweg-Plandsoen, W. C.; Cnossen, M. H.; van Tijn, D. A.; Hennekam, R. C.

    1998-01-01

    The simultaneous occurrence of familial neurofibromatosis type 1 (NF1) and an overgrowth syndrome resembling Weaver syndrome was observed in two related cases (a mother and her son). NF1 was confirmed by molecular genetic analysis showing a large deletion at 17q11.2, encompassing the entire NF1

  13. Descriptive Understandings of the Nature of Science: Examining the Consensual and Family Resemblance Approaches

    Science.gov (United States)

    do Nascimento Rocha, Maristela; Gurgel, Ivã

    2017-01-01

    This paper performs a critical analysis of the consensual and family resemblance approaches to the nature of science. Despite the debate that surrounds them, between a pragmatic consensus and a more comprehensive understanding, both approaches have in common the goal of helping students to "internalize" knowledge about science in a…

  14. Central nervous system and vertebral malformation resembling the Arnold-Chiari syndrome in a Simmental calf.

    OpenAIRE

    LeClerc, S; López, A; Illanes, O

    1997-01-01

    Multiple congenital anomalies were identified in a stillborn calf, including severe cerebellar hypoplasia and central nervous system abnormalities resembling the Arnold-Chiari syndrome of malformation of calves. The Arnold-Chiari malformation occurs sporadically and has little economic impact, whereas cerebellar hypoplasia implies the presence of BVD virus in the herd.

  15. Central nervous system and vertebral malformation resembling the Arnold-Chiari syndrome in a Simmental calf.

    Science.gov (United States)

    LeClerc, S; López, A; Illanes, O

    1997-01-01

    Multiple congenital anomalies were identified in a stillborn calf, including severe cerebellar hypoplasia and central nervous system abnormalities resembling the Arnold-Chiari syndrome of malformation of calves. The Arnold-Chiari malformation occurs sporadically and has little economic impact, whereas cerebellar hypoplasia implies the presence of BVD virus in the herd. Images Figure 1. PMID:9167880

  16. Repositioning of Somatic Golgi Apparatus Is Essential for the Dendritic Establishment of Adult-Born Hippocampal Neurons.

    Science.gov (United States)

    Rao, Sneha; Kirschen, Gregory W; Szczurkowska, Joanna; Di Antonio, Adrian; Wang, Jia; Ge, Shaoyu; Shelly, Maya

    2018-01-17

    New dentate granule cells (DGCs) are continuously generated, and integrate into the preexisting hippocampal network in the adult brain. How an adult-born neuron with initially simple spindle-like morphology develops into a DGC, consisting of a single apical dendrite with further branches, remains largely unknown. Here, using retroviruses to birth date and manipulate newborn neurons, we examined initial dendritic formation and possible underlying mechanisms. We found that GFP-expressing newborn cells began to establish a DGC-like morphology at ∼7 d after birth, with a primary dendrite pointing to the molecular layer, but at this stage, with several neurites in the neurogenic zone. Interestingly, the Golgi apparatus, an essential organelle for neurite growth and maintenance, was dynamically repositioning in the soma of newborn cells during this initial integration stage. Two weeks after birth, by which time most neurites in the neurogenic zone were eliminated, a compact Golgi apparatus was positioned exclusively at the base of the primary dendrite. We analyzed the presence of Golgi-associated genes using single-cell transcriptomes of newborn DGCs, and among Golgi-related genes, found the presence of STK25 and STRAD , regulators of embryonic neuronal development. When we knocked down either of these two proteins, we found Golgi mislocalization and extensive aberrant dendrite formation. Furthermore, overexpression of a mutated form of STRAD, underlying the disorder polyhydramnios, megalencephaly, and symptomatic epilepsy, characterized by abnormal brain development and intractable epilepsy, caused similar defects in Golgi localization and dendrite formation in adult-born neurons. Together, our findings reveal a role for Golgi repositioning in regulating the initial integration of adult-born DGCs. SIGNIFICANCE STATEMENT Since the discovery of the continuous generation of new neurons in the adult hippocampus, extensive effort was directed toward understanding the

  17. The Proprotein Convertase KPC-1/Furin Controls Branching and Self-avoidance of Sensory Dendrites in Caenorhabditis elegans

    Science.gov (United States)

    Bülow, Hannes E.

    2014-01-01

    Animals sample their environment through sensory neurons with often elaborately branched endings named dendritic arbors. In a genetic screen for genes involved in the development of the highly arborized somatosensory PVD neuron in C. elegans, we have identified mutations in kpc-1, which encodes the homolog of the proprotein convertase furin. We show that kpc-1/furin is necessary to promote the formation of higher order dendritic branches in PVD and to ensure self-avoidance of sister branches, but is likely not required during maintenance of dendritic arbors. A reporter for kpc-1/furin is expressed in neurons (including PVD) and kpc-1/furin can function cell-autonomously in PVD neurons to control patterning of dendritic arbors. Moreover, we show that kpc-1/furin also regulates the development of other neurons in all major neuronal classes in C. elegans, including aspects of branching and extension of neurites as well as cell positioning. Our data suggest that these developmental functions require proteolytic activity of KPC-1/furin. Recently, the skin-derived MNR-1/menorin and the neural cell adhesion molecule SAX-7/L1CAM have been shown to act as a tripartite complex with the leucine rich transmembrane receptor DMA-1 on PVD mechanosensory to orchestrate the patterning of dendritic branches. Genetic analyses show that kpc-1/furin functions in a pathway with MNR-1/menorin, SAX-7/L1CAM and DMA-1 to control dendritic branch formation and extension of PVD neurons. We propose that KPC-1/furin acts in concert with the ‘menorin’ pathway to control branching and growth of somatosensory dendrites in PVD. PMID:25232734

  18. Dendritic spread and functional coverage of starburst amacrine cells.

    Science.gov (United States)

    Keeley, Patrick W; Whitney, Irene E; Raven, Mary A; Reese, Benjamin E

    2007-12-10

    The network of starburst amacrine cells plays a fundamental role in the neural circuitry underlying directional selectivity within the retina. Individual sectors of the starburst dendritic field are directionally selective by virtue of a mutually inhibitory relationship between starburst amacrine cells with overlapping dendrites. These features of the starburst amacrine cell network suggest that starburst cells regulate their dendritic overlap to ensure a uniform coverage of the retinal surface. The present study has compared the dendritic morphology of starburst amacrine cells in two different strains of mice that differ in starburst amacrine cell number. The A/J (A) strain contains about one-quarter fewer starburst amacrine cells than does the C57BL/6J (B6) strain, although the mosaics of starburst amacrine cells in both strains are comparably patterned. Dendritic field size, however, does not compensate for the difference in density, the A strain having a slightly smaller dendritic field relative to the B6 strain, yielding a significantly larger dendritic coverage factor for individual cells in the B6 strain. The area of the distal (output) annulus of the dendritic field occupies a comparable proportion of the overall field area in the two strains, but overlapping annuli establish a finer meshwork of co-fasciculating processes in the B6 strain. These results would suggest that the architecture of the dendritic network, rather than the overall size of the dendritic field, is dependent on the density of starburst amacrine cells. (c) 2007 Wiley-Liss, Inc.

  19. Multidendritic sensory neurons in the adult Drosophila abdomen: origins, dendritic morphology, and segment- and age-dependent programmed cell death

    Directory of Open Access Journals (Sweden)

    Sugimura Kaoru

    2009-10-01

    Full Text Available Abstract Background For the establishment of functional neural circuits that support a wide range of animal behaviors, initial circuits formed in early development have to be reorganized. One way to achieve this is local remodeling of the circuitry hardwiring. To genetically investigate the underlying mechanisms of this remodeling, one model system employs a major group of Drosophila multidendritic sensory neurons - the dendritic arborization (da neurons - which exhibit dramatic dendritic pruning and subsequent growth during metamorphosis. The 15 da neurons are identified in each larval abdominal hemisegment and are classified into four categories - classes I to IV - in order of increasing size of their receptive fields and/or arbor complexity at the mature larval stage. Our knowledge regarding the anatomy and developmental basis of adult da neurons is still fragmentary. Results We identified multidendritic neurons in the adult Drosophila abdomen, visualized the dendritic arbors of the individual neurons, and traced the origins of those cells back to the larval stage. There were six da neurons in abdominal hemisegment 3 or 4 (A3/4 of the pharate adult and the adult just after eclosion, five of which were persistent larval da neurons. We quantitatively analyzed dendritic arbors of three of the six adult neurons and examined expression in the pharate adult of key transcription factors that result in the larval class-selective dendritic morphologies. The 'baseline design' of A3/4 in the adult was further modified in a segment-dependent and age-dependent manner. One of our notable findings is that a larval class I neuron, ddaE, completed dendritic remodeling in A2 to A4 and then underwent caspase-dependent cell death within 1 week after eclosion, while homologous neurons in A5 and in more posterior segments degenerated at pupal stages. Another finding is that the dendritic arbor of a class IV neuron, v'ada, was immediately reshaped during post

  20. Sleeping dendrites: fiber-optic measurements of dendritic calcium activity in freely moving and sleeping animals

    Directory of Open Access Journals (Sweden)

    Julie Seibt

    2014-03-01

    Full Text Available Dendrites are the post-synaptic sites of most excitatory and inhibitory synapses in the brain, making them the main location of cortical information processing and synaptic plasticity. Although current hypotheses suggest a central role for sleep in proper cognitive function and brain plasticity, virtually nothing is known about changes in dendritic activity across the sleep-wake cycle and how waking experience modifies this activity. To start addressing these questions, we developed a method that allows long-term recordings of EEGs/EMG combined with in vivo cortical calcium (Ca2+ activity in freely moving and sleeping rats. We measured Ca2+ activity from populations of dendrites of layer (L 5 pyramidal neurons (n = 13 rats that we compared with Ca2+ activity from populations of neurons in L2/3 (n = 11 rats. L5 and L2/3 neurons were labelled using bolus injection of OGB1-AM or GCaMP6 (1. Ca2+ signals were detected using a fiber-optic system (cannula diameter = 400µm, transmitting the changes in fluorescence to a photodiode. Ca2+ fluctuations could then be correlated with ongoing changes in brain oscillatory activity during 5 major brain states: active wake [AW], quiet wake [QW], NREM, REM and NREM-REM transition (or intermediate state, [IS]. Our Ca2+ recordings show large transients in L5 dendrites and L2/3 neurons that oscillate predominantly at frequencies In summary, we show that this technique is successful in monitoring fluctuations in ongoing dendritic Ca2+ activity during natural brain states and allows, in principle, to combine behavioral measurement with imaging from various brain regions (e.g. deep structures in freely behaving animals. Using this method, we show that Ca2+ transients from populations of L2/3 neurons and L5 dendrites are deferentially regulated across the sleep/wake cycle, with dendritic activity being the highest during the IS sleep. Our correlation analysis suggests that specific sleep EEG activity during NREM and IS

  1. Axon and dendrite geography predict the specificity of synaptic connections in a functioning spinal cord network

    Directory of Open Access Journals (Sweden)

    Borisyuk Roman

    2007-09-01

    Full Text Available Abstract Background How specific are the synaptic connections formed as neuronal networks develop and can simple rules account for the formation of functioning circuits? These questions are assessed in the spinal circuits controlling swimming in hatchling frog tadpoles. This is possible because detailed information is now available on the identity and synaptic connections of the main types of neuron. Results The probabilities of synapses between 7 types of identified spinal neuron were measured directly by making electrical recordings from 500 pairs of neurons. For the same neuron types, the dorso-ventral distributions of axons and dendrites were measured and then used to calculate the probabilities that axons would encounter particular dendrites and so potentially form synaptic connections. Surprisingly, synapses were found between all types of neuron but contact probabilities could be predicted simply by the anatomical overlap of their axons and dendrites. These results suggested that synapse formation may not require axons to recognise specific, correct dendrites. To test the plausibility of simpler hypotheses, we first made computational models that were able to generate longitudinal axon growth paths and reproduce the axon distribution patterns and synaptic contact probabilities found in the spinal cord. To test if probabilistic rules could produce functioning spinal networks, we then made realistic computational models of spinal cord neurons, giving them established cell-specific properties and connecting them into networks using the contact probabilities we had determined. A majority of these networks produced robust swimming activity. Conclusion Simple factors such as morphogen gradients controlling dorso-ventral soma, dendrite and axon positions may sufficiently constrain the synaptic connections made between different types of neuron as the spinal cord first develops and allow functional networks to form. Our analysis implies that

  2. Role of Dendritic Cells in Immune Dysfunction

    Science.gov (United States)

    Savary, Cherylyn A.

    1997-01-01

    Specific aims include: (1) Application of the bioreactor to enhance cytokine-regulated proliferation and maturation of dendritic cells (DC); (2) Based on clues from spaceflight: compare the frequency and function of DC in normal donors and immunocompromised cancer patients; and (3) Initiate studies on the efficiency of cytokine therapy and DC-assisted immunotherapy (using bioreactor-expanded DC) in animal models of experimental fungal infections.

  3. Argon gas atoms trapping by carbon dendrites

    Science.gov (United States)

    Danilaev, M. P.; Bogoslov, E. A.; Polskii, Y. E.

    2017-11-01

    The conditions of argon gas atoms trapping by carbon dendrites, which growing in atmospheric pressure gas-discharge plasma, are considered in that paper. It’s showing that the argons atoms trapping by the carbon diamond-like cell can occur in arc gas discharge with current density more than j 0 ∼ 45 mA/sm2 and provided that the eximer molecules of noble gas and carbon atoms (e.g., ArC) can be formed.

  4. Molecular identity of dendritic voltage-gated sodium channels.

    Science.gov (United States)

    Lorincz, Andrea; Nusser, Zoltan

    2010-05-14

    Active invasion of the dendritic tree by action potentials (APs) generated in the axon is essential for associative synaptic plasticity and neuronal ensemble formation. In cortical pyramidal cells (PCs), this AP back-propagation is supported by dendritic voltage-gated Na+ (Nav) channels, whose molecular identity is unknown. Using a highly sensitive electron microscopic immunogold technique, we revealed the presence of the Nav1.6 subunit in hippocampal CA1 PC proximal and distal dendrites. Here, the subunit density is lower by a factor of 35 to 80 than that found in axon initial segments. A gradual decrease in Nav1.6 density along the proximodistal axis of the dendritic tree was also detected without any labeling in dendritic spines. Our results reveal the characteristic subcellular distribution of the Nav1.6 subunit, identifying this molecule as a key substrate enabling dendritic excitability.

  5. Gastrointestinal symptoms resembling ulcerative proctitis caused by larvae of the drone fly Eristalis tenax.

    Science.gov (United States)

    Desoubeaux, Guillaume; Gaillard, Julien; Borée-Moreau, Diane; Bailly, Éric; Andres, Christian R; Chandenier, Jacques

    2014-04-01

    We report a case of facultative intestinal myiasis due to larvae of the drone fly Eristalis tenax, also named the rat-tailed maggots. The development of larvae in the lower bowel was responsible for non-specific gastrointestinal symptoms that resembled ulcerative proctitis. The diagnosis was established upon the observation of four spontaneously excreted mobile larvae. The definite identification of the E. tenax species was made possible by scanning electron microscopy. The clinical outcome was satisfactory.

  6. Corticomedullary mixed tumour resembling a small adrenal gland-involvement of cancer stem cells: case report

    OpenAIRE

    Duan, Lian; Fang, Fang; Fu, Wanlei; Fang, Zhenqiang; Wang, Hui; Yu, Shicang; Tang, Zili; Liu, Zhenqi; Zheng, Hongting

    2017-01-01

    Background Adrenal corticomedullary mixed tumours are very rare. Its mechanism is rarely reported. Here we report the first case of a corticomedullary mixed tumour resembling a ?small adrenal gland? with distinct arrangement of the cortical and medullary layers. We further hypothesize regarding the tumorigenic mechanism of this tumour. Case presentation A 58-year man had been diagnosed with diabetes and hypertension for 3?years. His 24-h urine vanillylmandelic acid (VMA) levels were slightly ...

  7. Which Football Player Bears Most Resemblance to Messi? A Statistical Analysis

    OpenAIRE

    Mazurek, Jiri

    2018-01-01

    Many pundits and fans ask themselves the same question: Which football player bears most resemblance to Lionel Messi? Is it Chelsea's Eden Hazard? Is it Paulo Dybala, the heir to Messi in the national team of Argentina? Or is the most alike player to Messi someone completely else? In general, the research on the evaluation of players' performances originated in the context of baseball in the USA, but, currently, it is of great importance in almost every team sport on the planet. Specifically,...

  8. Facial Resemblance Exaggerates Sex-Specific Jealousy-Based Decisions1

    Directory of Open Access Journals (Sweden)

    Steven M. Platek

    2007-01-01

    Full Text Available Sex differences in reaction to a romantic partner's infidelity are well documented and are hypothesized to be attributable to sex-specific jealousy mechanisms which are utilized to solve adaptive problems associated with risk of extra-pair copulation. Males, because of the risk of cuckoldry become more upset by sexual infidelity, while females, because of loss of resources and biparental investment tend to become more distressed by emotional infidelity. However, the degree to which these sex-specific reactions to jealousy interact with cues to kin are completely unknown. Here we investigated the interaction of facial resemblance with decisions about sex-specific jealousy scenarios. Fifty nine volunteers were asked to imagine that two different people (represented by facial composites informed them about their romantic partner's sexual or emotional infidelity. Consistent with previous research, males ranked sexual infidelity scenarios as most upsetting and females ranked emotional infidelity scenarios most upsetting. However, when information about the infidelity was provided by a face that resembled the subject, sex-specific reactions to jealousy were exaggerated. This finding highlights the use of facial resemblance as a putative self-referent phenotypic matching cue that impacts trusting behavior in sexual contexts.

  9. Immune monitoring using mRNA-transfected dendritic cells

    DEFF Research Database (Denmark)

    Borch, Troels Holz; Svane, Inge Marie; Met, Özcan

    2016-01-01

    Dendritic cells are known to be the most potent antigen presenting cell in the immune system and are used as cellular adjuvants in therapeutic anticancer vaccines using various tumor-associated antigens or their derivatives. One way of loading antigen into the dendritic cells is by m...... and understand the immunological impact of dendritic cell vaccination in order to improve clinical benefit. In this chapter, we describe a method for performing immune monitoring using peripheral blood mononuclear cells and autologous dendritic cells transfected with tumor-associated antigen-encoding mRNA....

  10. Tertiary dendritic instability in late stage solidification of Ni-based superalloys

    Science.gov (United States)

    Franke, M. M.; Singer, R. F.; Steinbach, I.

    2014-03-01

    Derivatives of the commercial alloy CMSX-4 were directionally solidified and characterized with respect to their final dendrite microstructure. The results indicate that Ni-based superalloys with high segregation levels show significant instability in secondary dendrite arms and an increased tendency for tertiary arm formation, respectively. Phase-field simulations were used to explore the impact of chemical composition on morphological instability and tertiary arm formation during the directional solidification of Ni-based superalloys. It is found that an increase in specific alloying elements in the overall alloy composition leads to pronounced segregation at the end of solidification. This causes strong growth restriction of the secondary arms and triggers tertiary arm formation. The proposed mechanism explains experimental microstructures found in modifications of the base alloy CMSX-4.

  11. The effect of gravity level on the average primary dendritic spacing of a directionally solidified superalloy

    Science.gov (United States)

    Mccay, M. H.; Lee, J. E.; Curreri, P. A.

    1986-01-01

    The effect of alternating low (0.01 g) and high (1.8 g) gravity force on the primary spacings in the dendrite structure in a directionally solidified Ni-based superalloy (PWA 1480, containing 5 pct Co, 10 pct Cr, 4 pct W, 12 pct Ta, 5 pct Al, 1.5 pct Ti, and the balance Ni) was investigated using samples solidified in a directional solidification furnace aboard the NASA KC-135 aircraft that made a series of low-g parabolas. The cross-section slices for each growth rate were polished and etched with Kallings II, and the primary dendritic arm spacings were measured using the method of Jacobi and Schwerdtfeger (1976). The arm spacings were found to fluctuate with gravity force, increasing as the gravity level decreased, and growing finer as gravity increased.

  12. Multi-Walled Carbon Nanotube-Assisted Electrodeposition of Silver Dendrite Coating as a Catalytic Film

    Directory of Open Access Journals (Sweden)

    Li Fu

    2017-12-01

    Full Text Available A multi-walled carbon nanotube (MWCNT-coated indium tin oxide (ITO slide was used as a platform for the growth of a silver dendrite (Ag-D film using cyclic voltammetry. The particular dendritic nanostructures were formed by the diffusion-limited-aggregation model due to the potential difference between the MWCNTs and the ITO surface. The Ag-D-coated ITO film was then used for the catalytic degradation of methyl orange (MO and methylene blue (MB under static aqueous conditions. The network structure of the Ag-D allows the efficient diffusion of MO and MB, and consequently enhances the catalytic performance. Since the thin film is much easier to use for the post-treatment of powder catalysts, the proposed method shows great potential in many catalytic applications.

  13. Interfacial wave theory of pattern formation in solidification dendrites, fingers, cells and free boundaries

    CERN Document Server

    Xu, Jian-Jun

    2017-01-01

    This comprehensive work explores interfacial instability and pattern formation in dynamic systems away from the equilibrium state in solidification and crystal growth. Further, this significantly expanded 2nd edition introduces and reviews the progress made during the last two decades. In particular, it describes the most prominent pattern formation phenomena commonly observed in material processing and crystal growth in the framework of the previously established interfacial wave theory, including free dendritic growth from undercooled melt, cellular growth and eutectic growth in directional solidification, as well as viscous fingering in Hele-Shaw flow. It elucidates the key problems, systematically derives their mathematical solutions by pursuing a unified, asymptotic approach, and finally carefully examines these results by comparing them with the available experimental results. The asymptotic approach described here will be useful for the investigation of pattern formation phenomena occurring in a much b...

  14. Nanofibrous nonwovens based on dendritic-linear-dendritic poly(ethylene glycol) hybrids

    DEFF Research Database (Denmark)

    Kikionis, Stefanos; Ioannou, Efstathia; Andren, Oliver C.J.

    2017-01-01

    unsuccessful. Nevertheless, when these DLD hybrids were blended with an array of different biodegradable polymers as entanglement enhancers, nanofibrous nonwovens were successfully prepared by electrospinning. The pseudogeneration degree of the DLDs, the nature of the co-electrospun polymer and the solvent...... nanofibers. Such dendritic nanofibrous scaffolds can be promising materials for biomedical applications due to their biocompatibility, biodegradability, multifunctionality, and advanced structural architecture....

  15. CTLA-4 blockade during dendritic cell based booster vaccination influences dendritic cell survival and CTL expansion

    DEFF Research Database (Denmark)

    Pedersen, Anders E; Ronchese, Franca

    2007-01-01

    Dendritic cells (DCs) are potent antigen-presenting cells and critical for the priming of CD8+ T cells. Therefore the use of these cells as adjuvant cells has been tested in a large number of experimental and clinical vaccination studies, in particular cancer vaccine studies. A number of protocols...

  16. Gliadin fragments promote migration of dendritic cells

    Czech Academy of Sciences Publication Activity Database

    Chládková, Barbara; Kamanová, Jana; Palová-Jelínková, Lenka; Cinová, Jana; Šebo, Peter; Tučková, Ludmila

    2011-01-01

    Roč. 15, č. 4 (2011), 938-948 ISSN 1582-1838 R&D Projects: GA ČR GA310/07/0414; GA ČR GD310/08/H077; GA ČR GA310/08/0447; GA AV ČR IAA500200801; GA AV ČR IAA500200914 Institutional research plan: CEZ:AV0Z50200510 Keywords : celiac disease * gliadin * dendritic cell Subject RIV: EC - Immunology Impact factor: 4.125, year: 2011

  17. Dendritic Cells as Danger-Recognizing Biosensors

    Directory of Open Access Journals (Sweden)

    Seokmann Hong

    2009-08-01

    Full Text Available Dendritic cells (DCs are antigen presenting cells that are characterized by a potent capacity to initiate immune responses. DCs comprise several subsets with distinct phenotypes. After sensing any danger(s to the host via their innate immune receptors such as Toll-like receptors, DCs become mature and subsequently present antigens to CD4+ T cells. Since DCs possess the intrinsic capacity to polarize CD4+ helper cells, it is critical to understand the immunological roles of DCs for clinical applications. Here, we review the different DC subsets, their danger-sensing receptors and immunological functions. Furthermore, the cytokine reporter mouse model for studying DC activation is introduced.

  18. Channelopathies and dendritic dysfunction in fragile X syndrome.

    Science.gov (United States)

    Brager, Darrin H; Johnston, Daniel

    2014-04-01

    Dendritic spine abnormalities and the metabotropic glutamate receptor theory put the focus squarely on synapses and protein synthesis as the cellular locus of fragile X syndrome. Synapses however, are only partly responsible for information processing in neuronal networks. Neurotransmitter triggered excitatory postsynaptic potentials (EPSPs) are shaped and integrated by dendritic voltage-gated ion channels. These EPSPs, and in some cases the resultant dendritic spikes, are further modified by dendritic voltage-gated ion channels as they propagate to the soma. If the resultant somatic depolarization is large enough, action potential(s) will be triggered and propagate both orthodromically down the axon, where it may trigger neurotransmitter release, and antidromically back into the dendritic tree, where it can activate and modify dendritic voltage-gated and receptor activated ion channels. Several channelopathies, both soma-dendritic (L-type calcium channels, Slack potassium channels, h-channels, A-type potassium channels) and axo-somatic (BK channels and delayed rectifier potassium channels) were identified in the fmr1-/y mouse model of fragile X syndrome. Pathological function of these channels will strongly influence the excitability of individual neurons as well as overall network function. In this chapter we discuss the role of voltage-gated ion channels in neuronal processing and describe how identified channelopathies in models of fragile X syndrome may play a role in dendritic pathophysiology. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Musical representation of dendritic spine distribution: a new exploratory tool.

    Science.gov (United States)

    Toharia, Pablo; Morales, Juan; de Juan, Octavio; Fernaud, Isabel; Rodríguez, Angel; DeFelipe, Javier

    2014-04-01

    Dendritic spines are small protrusions along the dendrites of many types of neurons in the central nervous system and represent the major target of excitatory synapses. For this reason, numerous anatomical, physiological and computational studies have focused on these structures. In the cerebral cortex the most abundant and characteristic neuronal type are pyramidal cells (about 85 % of all neurons) and their dendritic spines are the main postsynaptic target of excitatory glutamatergic synapses. Thus, our understanding of the synaptic organization of the cerebral cortex largely depends on the knowledge regarding synaptic inputs to dendritic spines of pyramidal cells. Much of the structural data on dendritic spines produced by modern neuroscience involves the quantitative analysis of image stacks from light and electron microscopy, using standard statistical and mathematical tools and software developed to this end. Here, we present a new method with musical feedback for exploring dendritic spine morphology and distribution patterns in pyramidal neurons. We demonstrate that audio analysis of spiny dendrites with apparently similar morphology may "sound" quite different, revealing anatomical substrates that are not apparent from simple visual inspection. These morphological/music translations may serve as a guide for further mathematical analysis of the design of the pyramidal neurons and of spiny dendrites in general.

  20. Barriers in the brain : resolving dendritic spine morphology and compartmentalization

    NARCIS (Netherlands)

    Adrian, Max; Kusters, Remy; Wierenga, Corette J; Storm, Cornelis; Hoogenraad, Casper C; Kapitein, Lukas C

    2014-01-01

    Dendritic spines are micron-sized protrusions that harbor the majority of excitatory synapses in the central nervous system. The head of the spine is connected to the dendritic shaft by a 50-400 nm thin membrane tube, called the spine neck, which has been hypothesized to confine biochemical and

  1. Facile fabrication of dendritic silver structures and their surface ...

    Indian Academy of Sciences (India)

    The dendritic or fractal Ag nanostructures have attracted the attention of scientists recently due to their attractive supramolecular structures, large surface area and excellent connectivity between the different parts of the structures. Significantly, it has been established that dendritic or fractal Ag nanostructures are an excel-.

  2. Modelling dendritic ecological networks in space: An integrated network perspective

    Science.gov (United States)

    Erin E. Peterson; Jay M. Ver Hoef; Dan J. Isaak; Jeffrey A. Falke; Marie-Josee Fortin; Chris E. Jordan; Kristina McNyset; Pascal Monestiez; Aaron S. Ruesch; Aritra Sengupta; Nicholas Som; E. Ashley Steel; David M. Theobald; Christian E. Torgersen; Seth J. Wenger

    2013-01-01

    Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships in other types of...

  3. Resembling a viper: implications of mimicry for conservation of the endangered smooth snake.

    Science.gov (United States)

    Valkonen, Janne K; Mappes, Johanna

    2014-12-01

    The phenomenon of Batesian mimicry, where a palatable animal gains protection against predation by resembling an unpalatable model, has been a core interest of evolutionary biologists for 150 years. An extensive range of studies has focused on revealing mechanistic aspects of mimicry (shared education and generalization of predators) and the evolutionary dynamics of mimicry systems (co-operation vs. conflict) and revealed that protective mimicry is widespread and is important for individual fitness. However, according to our knowledge, there are no case studies where mimicry theories have been applied to conservation of mimetic species. Theoretically, mimicry affects, for example, frequency dependency of predator avoidance learning and human induced mortality. We examined the case of the protected, endangered, nonvenomous smooth snake (Coronella austriaca) that mimics the nonprotected venomous adder (Vipera berus), both of which occur in the Åland archipelago, Finland. To quantify the added predation risk on smooth snakes caused by the rarity of vipers, we calculated risk estimates from experimental data. Resemblance of vipers enhances survival of smooth snakes against bird predation because many predators avoid touching venomous vipers. Mimetic resemblance is however disadvantageous against human predators, who kill venomous vipers and accidentally kill endangered, protected smooth snakes. We found that the effective population size of the adders in Åland is very low relative to its smooth snake mimic (28.93 and 41.35, respectively).Because Batesian mimicry is advantageous for the mimic only if model species exist in sufficiently high numbers, it is likely that the conservation program for smooth snakes will fail if adders continue to be destroyed. Understanding the population consequences of mimetic species may be crucial to the success of endangered species conservation. We suggest that when a Batesian mimic requires protection, conservation planners should

  4. Rupture Resemblance Score (RRS): toward risk stratification of unruptured intracranial aneurysms using hemodynamic-morphological discriminants.

    Science.gov (United States)

    Xiang, Jianping; Yu, Jihnhee; Choi, Hoon; Dolan Fox, Jennifer M; Snyder, Kenneth V; Levy, Elad I; Siddiqui, Adnan H; Meng, Hui

    2015-07-01

    We have previously developed three logistic regression models for discriminating intracranial aneurysm rupture status from 119 aneurysms based on hemodynamic-morphological parameters. In this study we exploit their use as a tool for predicting the risk of rupture of aneurysms with a defined Rupture Resemblance Score (RRS). We collected three-dimensional images of 85 consecutive aneurysms, applied the three regression models and compared model performance at predicting rupture status against anecdotal metrics (aneurysm size and aspect ratio). We then reinterpreted the model-predicted probability as RRS, where the higher the score the closer the resemblance to previously known rupture components, and applied the RRS prospectively to four unruptured aneurysms with borderline treatment decisions. All three models yielded excellent sensitivity (0.78-0.83) and specificity (0.78-0.84) at a cutoff score of 50%, whereas aneurysm size and aspect ratio showed poor sensitivities (0.28 and 0.33, respectively). Lowering the cutoff score to 30% improved sensitivity to 0.90. The RRS identified most of the ruptured aneurysms and also some unruptured ones that closely resembled ruptured aneurysms hemodynamically and/or morphologically. The prospective application of the RRS to unruptured aneurysms shows that it could provide additional insights for treatment decisions. Previous regression models based on hemodynamic-morphological parameters are able to discriminate rupture in a new cohort in the same population. A higher probability of rupture is associated with larger size ratio, lower normalized wall shear stress and higher oscillatory shear index. The RRS could potentially stratify rupture risk and assist in treatment decision-making for unruptured aneurysms. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  5. PrPSc accumulation in neuronal plasma membranes links Notch-1 activation to dendritic degeneration in prion diseases

    Directory of Open Access Journals (Sweden)

    DeArmond Stephen J

    2010-01-01

    Full Text Available Abstract Prion diseases are disorders of protein conformation in which PrPC, the normal cellular conformer, is converted to an abnormal, protease-resistant conformer rPrPSc. Approximately 80% of rPrPSc accumulates in neuronal plasma membranes where it changes their physical properties and profoundly affects membrane functions. In this review we explain how rPrPSc is transported along axons to presynaptic boutons and how we envision the conversion of PrPC to rPrPSc in the postsynaptic membrane. This information is a prerequisite to the second half of this review in which we present evidence that rPrPSc accumulation in synaptic regions links Notch-1 signaling with the dendritic degeneration. The hypothesis that the Notch-1 intracellular domain, NICD, is involved in prion disease was tested by treating prion-infected mice with the γ-secretase inhibitor (GSI LY411575, with quinacrine (Qa, and with the combination of GSI + Qa. Surprisingly, treatment with GSI alone markedly decreased NICD but did not prevent dendritic degeneration. Qa alone produced near normal dendritic trees. The combined GSI + Qa treatment resulted in a richer dendritic tree than in controls. We speculate that treatment with GSI alone inhibited both stimulators and inhibitors of dendritic growth. With the combined GSI + Qa treatment, Qa modulated the effect of GSI perhaps by destabilizing membrane rafts. GSI + Qa decreased PrPSc in the neocortex and the hippocampus by 95%, but only by 50% in the thalamus where disease was begun by intrathalamic inoculation of prions. The results of this study indicate that GSI + Qa work synergistically to prevent dendrite degeneration and to block formation of PrPSc.

  6. A Drosophila gene encoding a protein resembling the human β-amyloid protein precursor

    International Nuclear Information System (INIS)

    Rosen, D.R.; Martin-Morris, L.; Luo, L.; White, K.

    1989-01-01

    The authors have isolated genomic and cDNA clones for a Drosophila gene resembling the human β-amyloid precursor protein (APP). This gene produces a nervous system-enriched 6.5-kilobase transcript. Sequencing of cDNAs derived from the 6.5-kilobase transcript predicts an 886-amino acid polypeptide. This polypeptide contains a putative transmembrane domain and exhibits strong sequence similarity to cytoplasmic and extracellular regions of the human β-amyloid precursor protein. There is a high probability that this Drosophila gene corresponds to the essential Drosophila locus vnd, a gene required for embryonic nervous system development

  7. Charge on luminous bodies resembling natural ball lightning produced via electrical arcs through lump silicon

    Science.gov (United States)

    Porter, Christina L.; Miley, Galen P.; Griffiths, David J.; Sánchez, Erik

    2014-12-01

    A phenomenon resembling natural ball lightning can be produced via electrical arcing through silicon. We use lump silicon instead of silicon wafers to achieve higher production rates and larger, longer-lived luminous balls than previously reported. The luminous balls consist of a silicon core surrounded by a porous network of loosely bound silicon dioxide nanoparticles. We find that the balls carry a small net charge on the order of 10-12 C and propose that the nanoparticles are electrostatically bound to the core due to this charge.

  8. Consolation in the aftermath of robberies resembles post-aggression consolation in chimpanzees

    DEFF Research Database (Denmark)

    Lindegaard, Marie Rosenkrantz; Liebst, Lasse Suonperä; Bernasco, Wim

    2017-01-01

    Post-aggression consolation is assumed to occur in humans as well as in chimpanzees. While consolation following peer aggression has been observed in children, systematic evidence of consolation in human adults is rare. We used surveillance camera footage of the immediate aftermath of nonfatal...... to be consoled. Furthermore, we show that high levels of threat during the robbery increased the likelihood of receiving consolation afterwards. These patterns resemble post-aggression consolation in chimpanzees and suggest that emotions of empathic concern are involved in consolation across humans...... and chimpanzees....

  9. A case of secondary syphilis with HIV, resembling borderline lepromatous leprosy

    Science.gov (United States)

    Mani, Mohan Zachariah; Kanish, Bimal; Kwatra, Kanwardeep; Chaudhary, Paulina R.; Bhatia, Anuradha

    2015-01-01

    We are reporting an unusual case of secondary syphilis, in a homosexual male patient, which resembled borderline lepromatous leprosy, and in whom the diagnosis was considered on clinical grounds. The patient also had concomitant HIV infection, with asymptomatic neurosyphilis. His rapid plasma reagin test was reactive in 1:128 dilution. He improved with three standard, weekly injections of benzathine penicillin, along with 2 g of intravenous ceftriaxone daily for 15 days. This case is being reported to highlight the need for a high index of suspicion in diagnosing unusual cases of secondary syphilis, especially in those with concomitant HIV infection. PMID:26692613

  10. Dendritic spines form 'collars' in hippocampal granule cells.

    Science.gov (United States)

    Rusakov, D A; Stewart, M G; Sojka, M; Richter-Levin, G; Bliss, T V

    1995-07-31

    A quantitative study of the distribution of dendritic spines was carried out in three orders of dendritic branches of granule cells from the dentate gyrus of the rat hippocampus. Golgi-stained preparations (7-19 neurones in each of seven rats) were analysed using computerized microscopy. Identification of spines and quantification of stem-spine geometry was performed using a segmentation algorithm and a line skeleton transformation of dendritic images. Analysis of data using the statistics of point processes revealed that, in all three branch orders, the distribution of visible spines along dendrites was not evenly random, but included dense clusters of spines surrounding the dendritic stem (spine 'collars'). Three-dimensional reconstructions from serial ultrathin sections have confirmed the presence of such spine groups. We speculate the spine collars represent a functional element in which associative synaptic plasticity is fostered by the proximity of individual synapses.

  11. Dendritic Connectivity, Heterogeneity, and Scaling in Urban Stormwater Networks: Implications for Socio-Hydrology

    Science.gov (United States)

    Mejia, A.; Jovanovic, T.; Hale, R. L.; Gironas, J. A.

    2017-12-01

    Urban stormwater networks (USNs) are unique dendritic (tree-like) structures that combine both artificial (e.g., swales and pipes) and natural (e.g., streams and wetlands) components. They are central to stream ecosystem structure and function in urban watersheds. The emphasis of conventional stormwater management, however, has been on localized, temporal impacts (e.g., changes to hydrographs at discrete locations), and the performance of individual stormwater control measures. This is the case even though control measures are implemented to prevent impacts on the USN. We develop a modeling approach to retrospectively study hydrological fluxes and states in USNs and apply the model to an urban watershed in Scottsdale, Arizona, USA. Using outputs from the model, we analyze over space and time the network properties of dendritic connectivity, heterogeneity, and scaling. Results show that as the network growth over time, due to increasing urbanization, it tends to become more homogenous in terms of topological features but increasingly heterogeneous in terms of dynamic features. We further use the modeling results to address socio-hydrological implications for USNs. We find that the adoption over time of evolving management strategies (e.g., widespread implementation of vegetated swales and retention ponds versus pipes) may be locally beneficial to the USN but benefits may not propagate systematically through the network. The latter can be reinforced by sudden, perhaps unintended, changes to the overall dendritic connectivity.

  12. Towards an improved Global Antioxidant Response method (GAR+): Physiological-resembling in vitro antioxidant capacity methods.

    Science.gov (United States)

    Pérez-Burillo, S; Rufián-Henares, J A; Pastoriza, S

    2018-01-15

    Many methods have been developed to measure the antioxidant capacity of foods under non physiological-relevant conditions. In this study, three methods (TEAC OH , GEAC RED and TEAC AAPH ) are developed to measure antioxidant capacity at physiological pH, using indigo carmine as a redox dye. TEAC OH and TEAC AAPH determine foodstuffs' scavenging capacity against hydroxyl (OH) and AAPH radicals, while the third method measures the global reducing capacity of the sample. The results obtained for commercial teas, commercial beverages containing tea as the main ingredient and different solid foods (spinach, onion, salami, etc.) were compared with well-established protocols. The new methods demonstrated good linearity-reproducibility, providing reliable data about the antioxidant capacity of foods under physiological-resembling conditions. The new methods were also useful for evaluating the antioxidant capacity of human plasma after acute intake of tea. The physiological-resembling conditions of these assays and the use of absorbance readings make them suitable for application by any laboratory. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Familial resemblance of borderline personality disorder features: genetic or cultural transmission?

    Directory of Open Access Journals (Sweden)

    Marijn A Distel

    Full Text Available Borderline personality disorder is a severe personality disorder for which genetic research has been limited to family studies and classical twin studies. These studies indicate that genetic effects explain 35 to 45% of the variance in borderline personality disorder and borderline personality features. However, effects of non-additive (dominance genetic factors, non-random mating and cultural transmission have generally not been explored. In the present study an extended twin-family design was applied to self-report data of twins (N = 5,017 and their siblings (N = 1,266, parents (N = 3,064 and spouses (N = 939 from 4,015 families, to estimate the effects of additive and non-additive genetic and environmental factors, cultural transmission and non-random mating on individual differences in borderline personality features. Results showed that resemblance among biological relatives could completely be attributed to genetic effects. Variation in borderline personality features was explained by additive genetic (21%; 95% CI 17-26% and dominant genetic (24%; 95% CI 17-31% factors. Environmental influences (55%; 95% CI 51-60% explained the remaining variance. Significant resemblance between spouses was observed, which was best explained by phenotypic assortative mating, but it had only a small effect on the genetic variance (1% of the total variance. There was no effect of cultural transmission from parents to offspring.

  14. Loss of Dendritic Complexity Precedes Neurodegeneration in a Mouse Model with Disrupted Mitochondrial Distribution in Mature Dendrites

    Directory of Open Access Journals (Sweden)

    Guillermo López-Doménech

    2016-10-01

    Full Text Available Correct mitochondrial distribution is critical for satisfying local energy demands and calcium buffering requirements and supporting key cellular processes. The mitochondrially targeted proteins Miro1 and Miro2 are important components of the mitochondrial transport machinery, but their specific roles in neuronal development, maintenance, and survival remain poorly understood. Using mouse knockout strategies, we demonstrate that Miro1, as opposed to Miro2, is the primary regulator of mitochondrial transport in both axons and dendrites. Miro1 deletion leads to depletion of mitochondria from distal dendrites but not axons, accompanied by a marked reduction in dendritic complexity. Disrupting postnatal mitochondrial distribution in vivo by deleting Miro1 in mature neurons causes a progressive loss of distal dendrites and compromises neuronal survival. Thus, the local availability of mitochondrial mass is critical for generating and sustaining dendritic arbors, and disruption of mitochondrial distribution in mature neurons is associated with neurodegeneration.

  15. Using Dendritic Heat Maps to Simultaneously Display Genotype Divergence with Phenotype Divergence.

    Science.gov (United States)

    Kellom, Matthew; Raymond, Jason

    2016-01-01

    The advancement of techniques to visualize and analyze large-scale sequencing datasets is an area of active research and is rooted in traditional techniques such as heat maps and dendrograms. We introduce dendritic heat maps that display heat map results over aligned DNA sequence clusters for a range of clustering cutoffs. Dendritic heat maps aid in visualizing the effects of group differences on clustering hierarchy and relative abundance of sampled sequences. Here, we artificially generate two separate datasets with simplified mutation and population growth procedures with GC content group separation to use as example phenotypes. In this work, we use the term phenotype to represent any feature by which groups can be separated. These sequences were clustered in a fractional identity range of 0.75 to 1.0 using agglomerative minimum-, maximum-, and average-linkage algorithms, as well as a divisive centroid-based algorithm. We demonstrate that dendritic heat maps give freedom to scrutinize specific clustering levels across a range of cutoffs, track changes in phenotype inequity across multiple levels of sequence clustering specificity, and easily visualize how deeply rooted changes in phenotype inequity are in a dataset. As genotypes diverge in sample populations, clusters are shown to break apart into smaller clusters at higher identity cutoff levels, similar to a dendrogram. Phenotype divergence, which is shown as a heat map of relative abundance bin response, may or may not follow genotype divergences. This joined view highlights the relationship between genotype and phenotype divergence for treatment groups. We discuss the minimum-, maximum-, average-, and centroid-linkage algorithm approaches to building dendritic heat maps and make a case for the divisive "top-down" centroid-based clustering methodology as being the best option visualize the effects of changing factors on clustering hierarchy and relative abundance.

  16. Using Dendritic Heat Maps to Simultaneously Display Genotype Divergence with Phenotype Divergence.

    Directory of Open Access Journals (Sweden)

    Matthew Kellom

    Full Text Available The advancement of techniques to visualize and analyze large-scale sequencing datasets is an area of active research and is rooted in traditional techniques such as heat maps and dendrograms. We introduce dendritic heat maps that display heat map results over aligned DNA sequence clusters for a range of clustering cutoffs. Dendritic heat maps aid in visualizing the effects of group differences on clustering hierarchy and relative abundance of sampled sequences. Here, we artificially generate two separate datasets with simplified mutation and population growth procedures with GC content group separation to use as example phenotypes. In this work, we use the term phenotype to represent any feature by which groups can be separated. These sequences were clustered in a fractional identity range of 0.75 to 1.0 using agglomerative minimum-, maximum-, and average-linkage algorithms, as well as a divisive centroid-based algorithm. We demonstrate that dendritic heat maps give freedom to scrutinize specific clustering levels across a range of cutoffs, track changes in phenotype inequity across multiple levels of sequence clustering specificity, and easily visualize how deeply rooted changes in phenotype inequity are in a dataset. As genotypes diverge in sample populations, clusters are shown to break apart into smaller clusters at higher identity cutoff levels, similar to a dendrogram. Phenotype divergence, which is shown as a heat map of relative abundance bin response, may or may not follow genotype divergences. This joined view highlights the relationship between genotype and phenotype divergence for treatment groups. We discuss the minimum-, maximum-, average-, and centroid-linkage algorithm approaches to building dendritic heat maps and make a case for the divisive "top-down" centroid-based clustering methodology as being the best option visualize the effects of changing factors on clustering hierarchy and relative abundance.

  17. Electrochemical fabrication of clean dendritic Au supported Pt clusters for electrocatalytic oxidation of formic acid

    International Nuclear Information System (INIS)

    Xia Yue; Liu Jun; Huang Wei; Li Zelin

    2012-01-01

    Highlights: ► A smooth Au surface was rebuilt into clean dendrite via square wave potential pulses. ► It was performed in blank H 2 SO 4 solution without Au(III) species and other additives. ► Dendritic Au provided certain advantage for dispersing Pt due to its unique structure. ► Pt-decorated dendritic Au demonstrated high activity for the HCOOH electrooxidation. - Abstract: We report here the fabrication of clean dendritic gold (DG) directly on a smooth Au electrode via square wave potential pulses (SWPPs) in a blank H 2 SO 4 solution containing no Au(III) species and additives. The effects of potential range, frequency and duration time of SWPPs and H 2 SO 4 concentration on the construction of DG were systematically investigated. A possible mechanism was proposed to explain the growth of DG. The whole process was templateless and surfactantless, and therefore effectively avoided possible contaminations that occurred in other synthetic routes. Further, the prepared DG electrode functioned as a scaffold to support electrodeposited Pt clusters, producing Pt-decorated DG (Pt-DG) electrodes. The electrocatalytic properties of Pt-DG electrodes with various Pt loadings were examined for the oxidation of formic acid. The low Pt loading Pt-DG demonstrated different electrochemical behavior from that on Pt-decorated smooth gold (Pt-SG) and on Pt-decorated gold nanoparticles because there were more defect sites like steps and edges on the DG surface. Ensemble effect, as well as electronic effect, accounts for the improved electrocatalytic activity of low Pt loading Pt-DG.

  18. Oscillating-Crucible Technique for Silicon Growth

    Science.gov (United States)

    Daud, T.; Dumas, K. A.; Kim, K. M.; Schwuttke, G. H.; Smetana, P.

    1984-01-01

    Technique yields better mixing of impurities and superior qualiity crystals. Accellerated motion stirs melt which reduces temperature gradients and decreases boundary layer for diffusion of impurities near growing surface. Results better mixing of impurities into melt, decrease in tendency for dendritic growth or cellular growth and crystals with low dislocation density. Applied with success to solution growth and Czochralski growth, resulting in large crystals of superior quality.

  19. Linking Memories across Time via Neuronal and Dendritic Overlaps in Model Neurons with Active Dendrites

    Directory of Open Access Journals (Sweden)

    George Kastellakis

    2016-11-01

    Full Text Available Memories are believed to be stored in distributed neuronal assemblies through activity-induced changes in synaptic and intrinsic properties. However, the specific mechanisms by which different memories become associated or linked remain a mystery. Here, we develop a simplified, biophysically inspired network model that incorporates multiple plasticity processes and explains linking of information at three different levels: (1 learning of a single associative memory, (2 rescuing of a weak memory when paired with a strong one, and (3 linking of multiple memories across time. By dissecting synaptic from intrinsic plasticity and neuron-wide from dendritically restricted protein capture, the model reveals a simple, unifying principle: linked memories share synaptic clusters within the dendrites of overlapping populations of neurons. The model generates numerous experimentally testable predictions regarding the cellular and sub-cellular properties of memory engrams as well as their spatiotemporal interactions.

  20. Adolescent cocaine exposure simplifies orbitofrontal cortical dendritic arbors

    Directory of Open Access Journals (Sweden)

    Lauren M DePoy

    2014-10-01

    Full Text Available Cocaine and amphetamine remodel dendritic spines within discrete cortico-limbic brain structures including the orbitofrontal cortex (oPFC. Whether dendrite structure is similarly affected, and whether pre-existing cellular characteristics influence behavioral vulnerabilities to drugs of abuse, remain unclear. Animal models provide an ideal venue to address these issues because neurobehavioral phenotypes can be defined both before, and following, drug exposure. We exposed mice to cocaine from postnatal days 31-35, corresponding to early adolescence, using a dosing protocol that causes impairments in an instrumental reversal task in adulthood. We then imaged and reconstructed excitatory neurons in deep-layer oPFC. Prior cocaine exposure shortened and simplified arbors, particularly in the basal region. Next, we imaged and reconstructed orbital neurons in a developmental-genetic model of cocaine vulnerability – the p190rhogap+/- mouse. p190RhoGAP is an actin cytoskeleton regulatory protein that stabilizes dendrites and dendritic spines, and p190rhogap+/- mice develop rapid and robust locomotor activation in response to cocaine. Despite this, oPFC dendritic arbors were intact in drug-naïve p190rhogap+/- mice. Together, these findings provide evidence that adolescent cocaine exposure has long-term effects on dendrite structure in the oPFC, and they suggest that cocaine-induced modifications in dendrite structure may contribute to the behavioral effects of cocaine more so than pre-existing structural abnormalities in this cell population.

  1. Dendritic mitochondria reach stable positions during circuit development

    Science.gov (United States)

    Faits, Michelle C; Zhang, Chunmeng; Soto, Florentina; Kerschensteiner, Daniel

    2016-01-01

    Mitochondria move throughout neuronal dendrites and localize to sites of energy demand. The prevailing view of dendritic mitochondria as highly motile organelles whose distribution is continually adjusted by neuronal activity via Ca2+-dependent arrests is based on observations in cultured neurons exposed to artificial stimuli. Here, we analyze the movements of mitochondria in ganglion cell dendrites in the intact retina. We find that whereas during development 30% of mitochondria are motile at any time, as dendrites mature, mitochondria all but stop moving and localize stably to synapses and branch points. Neither spontaneous nor sensory-evoked activity and Ca2+ transients alter motility of dendritic mitochondria; and pathological hyperactivity in a mouse model of retinal degeneration elevates rather than reduces motility. Thus, our findings indicate that dendritic mitochondria reach stable positions during a critical developmental period of high motility, and challenge current views about the role of activity in regulating mitochondrial transport in dendrites. DOI: http://dx.doi.org/10.7554/eLife.11583.001 PMID:26742087

  2. Dendritic cell-based vaccine efficacy: aiming for hot spots

    Directory of Open Access Journals (Sweden)

    Gabriela Andrea Pizzurro

    2015-03-01

    Full Text Available Many approaches for cancer immunotherapy have targeted dendritic cells (DC, directly or indirectly, for the induction of antitumor immune responses. DC-based vaccines have been developed using a wide variety of ex vivo DC culture conditions, antigen source and loading strategies, maturation agents and routes of vaccination. Adjuvants are used to activate innate immune cells at the vaccine injection site, to promote antigen transport to the draining lymph nodes (LNs and to model adaptive immune responses. Despite years of effort, the effective induction of strong and durable antitumor T cell responses in vaccinated patients remains a challenge. The study of vaccine interactions with other immune cells in the LNs and, more recently, in the injection site has opened new doors for understanding antitumor effector T cell licensing and function. In this review, we will briefly discuss the relevant sites and up-to-date facts regarding possible targets for antitumor vaccine refinement. We will focus on the processes taking place at the injection site, adjuvant combinations and their role in DC-based vaccines LN homing and modeling vaccine-induced immune responses capable of controlling tumor growth and generating immune memory.

  3. Wnt-5a/Frizzled9 Receptor Signaling through the Gαo-Gβγ Complex Regulates Dendritic Spine Formation*

    Science.gov (United States)

    Ramírez, Valerie T.; Ramos-Fernández, Eva; Henríquez, Juan Pablo; Lorenzo, Alfredo; Inestrosa, Nibaldo C.

    2016-01-01

    Wnt ligands play crucial roles in the development and regulation of synapse structure and function. Specifically, Wnt-5a acts as a secreted growth factor that regulates dendritic spine formation in rodent hippocampal neurons, resulting in postsynaptic development that promotes the clustering of the PSD-95 (postsynaptic density protein 95). Here, we focused on the early events occurring after the interaction between Wnt-5a and its Frizzled receptor at the neuronal cell surface. Additionally, we studied the role of heterotrimeric G proteins in Wnt-5a-dependent synaptic development. We report that FZD9 (Frizzled9), a Wnt receptor related to Williams syndrome, is localized in the postsynaptic region, where it interacts with Wnt-5a. Functionally, FZD9 is required for the Wnt-5a-mediated increase in dendritic spine density. FZD9 forms a precoupled complex with Gαo under basal conditions that dissociates after Wnt-5a stimulation. Accordingly, we found that G protein inhibition abrogates the Wnt-5a-dependent pathway in hippocampal neurons. In particular, the activation of Gαo appears to be a key factor controlling the Wnt-5a-induced dendritic spine density. In addition, we found that Gβγ is required for the Wnt-5a-mediated increase in cytosolic calcium levels and spinogenesis. Our findings reveal that FZD9 and heterotrimeric G proteins regulate Wnt-5a signaling and dendritic spines in cultured hippocampal neurons. PMID:27402827

  4. Phase-field simulation on dendritic to semi-circular morphology transition induced by forced liquid flow

    Science.gov (United States)

    Du, Lifei; Zhang, Peng; Yang, Shaomei; Gao, Zhongtang; Chen, Jie; Du, Huiling

    2018-02-01

    A 2-D phase-field model coupling with convection is implemented to investigate the dendritic morphology evolution of the Ni-40.8%Cu alloy during solidification with forced liquid flow. Simulation results indicate that liquid flow can significantly affect the distributions of temperature and concentration near the liquid-solid interface, leading to asymmetric formation of the dendritic microstructure. Increasing the liquid flow will enhance the asymmetry of dendrite morphology with much more suppressed growth in the downstream and intensified morphology development in the upstream, leading to a dendritic to semi-circular morphology transition in the microstructure formation. Based on the simulations, it can be concluded that the morphology changes with increasing flow velocity in this study is attributed to the difference of the constitutional supercooling near the solid-liquid interfaces, which is the result of the asymmetric solute diffusion induced by the liquid flow. Therefore, controlling the liquid flow during the solidification might lead to the microstructure optimization to achieve materials with excellent properties.

  5. Differential Regulation of Apical-basolateral Dendrite Outgrowth by Activity in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Yang eYuan

    2015-08-01

    Full Text Available Hippocampal pyramidal neurons have characteristic dendrite asymmetry, characterized by structurally and functionally distinct apical and basolateral dendrites. The ability of the neuron to generate and maintain dendrite asymmetry is vital, since synaptic inputs received are critically dependent on dendrite architecture. Little is known about the role of neuronal activity in guiding maintainance of dendrite asymmetry. Our data indicate that dendrite asymmetry is established and maintained early during development. Further, our results indicate that cell intrinsic and global alterations of neuronal activity have differential effects on net extension of apical and basolateral dendrites. Thus, apical and basolateral dendrite extension may be independently regulated by cell intrinsic and network neuronal activity during development, suggesting that individual dendrites may have autonomous control over net extension. We propose that regulated individual dendrite extension in response to cell intrinsic and neuronal network activity may allow temporal control of synapse specificity in the developing hippocampus.

  6. Anastellin, an FN3 Fragment with Fibronectin Polymerization Activity, Resembles Amyloid Fibril Precursors

    Energy Technology Data Exchange (ETDEWEB)

    Briknarova, Klara (The Burnham Institute); Akermann, Maria (The Burnham Institute); Hoyt, David W.(BATTELLE (PACIFIC NW LAB)); Ruoslahti, Erkki (The Burnham Institute); Ely, Kathryn R.(The Burnham Institute)

    2003-08-01

    Anastellin is a carboxy-terminal fragment of the 1st FN3 domain from human fibronectin. It is capable of polymerizing fibronectin in vitro, and it displays anti-tumor, antimetastatic and anti-angiogenic properties in vivo. We have determined the structure of anastellin using nuclear magnetic resonance spectroscopy and identified residues critical for its activity. Anastellin exhibits dynamic fluctuations and conformational exchange in solution. Its overall topology is very similar to the corresponding region of full-length FN3 domains. However, its hydrophobic core becomes solvent accessible and some of its -strands lose their protection against hydrogen bonding to -strands from other molecules. These features seem to be relevant for the fibronectin polymerization activity of anastellin and resemble the characteristics of amyloid fibril precursors. We suggest that this analogy is not random and may reflect similarities between fibronectin and amyloid fibril formation.

  7. A renal adenocarcinoma in a corn snake (Pantherophis guttatus) resembling human collecting duct carcinoma.

    Science.gov (United States)

    Kao, Chi-Fei; Chen, Jiun-Liang; Tsao, Wen-Tien; Lee, An-Hsing; Liu, Chen-Hsuan; Wang, Fun-In

    2016-09-01

    A 5-year-old male captive corn snake (Pantherophis guttatus) with caudal coelomic swelling was admitted for surgical treatment. Laparotomy revealed a 5 × 4 × 2.5 cm, firm, expansile, irregularly shaped mass arising from the middle portion of the right kidney with a mild lobulated pattern and mottled white-to-tan. Microscopically, the mass was composed of numerous bizarre angulated tubules of polygonal neoplastic cells separated by a scirrhous stroma with remarkable heterophilic infiltrates. The neoplastic cells were nonciliated and mucin secreting, with abundant brightly eosinophilic cytoplasm. There were marked cellular and nuclear atypia, frequent cell individualization, and stromal invasion, indicative of malignant behavior, which was confirmed by metastasis to the left kidney 1.5 months postoperatively. Both neoplastic epithelial cells and mesenchymal cells contributing to the scirrhous stroma had variable immunopositivity for pan-cytokeratin. The neoplasm was considered a renal adenocarcinoma resembling human collecting duct carcinoma. © 2016 The Author(s).

  8. Westermarck, Freud, and the incest taboo: does familial resemblance activate sexual attraction?

    Science.gov (United States)

    Fraley, R Chris; Marks, Michael J

    2010-09-01

    Evolutionary psychological theories assume that sexual aversions toward kin are triggered by a nonconscious mechanism that estimates the genetic relatedness between self and other. This article presents an alternative perspective that assumes that incest avoidance arises from consciously acknowledged taboos and that when awareness of the relationship between self and other is bypassed, people find individuals who resemble their kin more sexually appealing. Three experiments demonstrate that people find others more sexually attractive if they have just been subliminally exposed to an image of their opposite-sex parent (Experiment 1) or if the face being rated is a composite image based on the self (Experiment 2). This finding is reversed when people are aware of the implied genetic relationship (Experiment 3). These findings have implications for a century-old debate between E. Westermarck and S. Freud, as well as contemporary research on evolution, mate choice, and sexual imprinting.

  9. A case of Scabies with Lesions Resembling Perforating Folliculitis and Uremic Pruritus

    Directory of Open Access Journals (Sweden)

    Hülya Akgün

    2010-10-01

    Full Text Available Scabies is an infestation caused by Sarcoptes scabiei and characterised by polymorphous lesions that may include burrows, papules, pustules, crusts and excoriations. Several pruritic diseases may be confused with scabies. Herein, we present a case of scabies with lesions resembling perforating folliculitis diagnosed on the basis of both clinical and histopathological view. A 72-year-old man with type 2 diabetes mellitus and receiving hemodialysis for ten years due to end-stage renal disease was admitted to our dermatology department with a 6-month history of severe pruritus. Based on the results of skin biopsy revealing Sarcoptes scabiei in the epidermis, the patient was diagnosed as scabies and was successfully treated with 5% permethrin. This case is presented to emphasize that scabies should be considered in the differential diagnosis in cases of chronic pruritus.

  10. Menstrual blood closely resembles the uterine immune micro-environment and is clearly distinct from peripheral blood

    NARCIS (Netherlands)

    Molen, R.G. van der; Schutten, J.H.; Cranenbroek, B. van; Meer, M. ter; Donckers, J.; Scholten, R.R.; Heijden, O.W.H. van der; Spaanderman, M.E.A.; Joosten, I.

    2014-01-01

    STUDY QUESTION: Is menstrual blood a suitable source of endometrial derived lymphocytes? SUMMARY ANSWER: Mononuclear cells isolated from menstrual samples (menstrual blood mononuclear cells (MMC)) are clearly distinct from peripheral blood mononuclear cells (PBMC) and show a strong resemblance with

  11. Dendritic cells and aging: consequences for autoimmunity.

    Science.gov (United States)

    Agrawal, Anshu; Sridharan, Aishwarya; Prakash, Sangeetha; Agrawal, Harsh

    2012-01-01

    The immune system has evolved to mount immune responses against foreign pathogens and to remain silent against self-antigens. A balance between immunity and tolerance is required as any disturbance may result in chronic inflammation or autoimmunity. Dendritic cells (DCs) actively participate in maintaining this balance. Under steady-state conditions, DCs remain in an immature state and do not mount an immune response against circulating self-antigens in the periphery, which maintains a state of tolerance. By contrast, foreign antigens result in DC maturation and DC-induced T-cell activation. Inappropriate maturation of DCs due to infections or tissue injury may cause alterations in the balance between the tolerogenic and immunogenic functions of DCs and instigate the development of autoimmune diseases. This article provides an overview of the effects of advancing age on DC functions and their implications in autoimmunity.

  12. Towards deep learning with segregated dendrites.

    Science.gov (United States)

    Guerguiev, Jordan; Lillicrap, Timothy P; Richards, Blake A

    2017-12-05

    Deep learning has led to significant advances in artificial intelligence, in part, by adopting strategies motivated by neurophysiology. However, it is unclear whether deep learning could occur in the real brain. Here, we show that a deep learning algorithm that utilizes multi-compartment neurons might help us to understand how the neocortex optimizes cost functions. Like neocortical pyramidal neurons, neurons in our model receive sensory information and higher-order feedback in electrotonically segregated compartments. Thanks to this segregation, neurons in different layers of the network can coordinate synaptic weight updates. As a result, the network learns to categorize images better than a single layer network. Furthermore, we show that our algorithm takes advantage of multilayer architectures to identify useful higher-order representations-the hallmark of deep learning. This work demonstrates that deep learning can be achieved using segregated dendritic compartments, which may help to explain the morphology of neocortical pyramidal neurons.

  13. Induction of RNA interference in dendritic cells.

    Science.gov (United States)

    Li, Mu; Qian, Hua; Ichim, Thomas E; Ge, Wei-Wen; Popov, Igor A; Rycerz, Katarzyna; Neu, John; White, David; Zhong, Robert; Min, Wei-Ping

    2004-01-01

    Dendritic cells (DC) reside at the center of the immunological universe, possessing the ability both to stimulate and inhibit various types of responses. Tolerogenic/regulatory DC with therapeutic properties can be generated through various means of manipulations in vitro and in vivo. Here we describe several attractive strategies for manipulation of DC using the novel technique of RNA interference (RNAi). Additionally, we overview some of our data regarding yet undescribed characteristics of RNAi in DC such as specific transfection strategies, persistence of gene silencing, and multi-gene silencing. The advantages of using RNAi for DC genetic manipulation gives rise to the promise of generating tailor-made DC that can be used effectively to treat a variety of immunologically mediated diseases.

  14. Targeting dendritic cells--why bother?

    Science.gov (United States)

    Kreutz, Martin; Tacken, Paul J; Figdor, Carl G

    2013-04-11

    Vaccination is among the most efficient forms of immunotherapy. Although sometimes inducing lifelong protective B-cell responses, T-cell-mediated immunity remains challenging. Targeting antigen to dendritic cells (DCs) is an extensively explored concept aimed at improving cellular immunity. The identification of various DC subsets with distinct functional characteristics now allows for the fine-tuning of targeting strategies. Although some of these DC subsets are regarded as superior for (cross-) priming of naive T cells, controversies still remain about which subset represents the best target for immunotherapy. Because targeting the antigen alone may not be sufficient to obtain effective T-cell responses, delivery systems have been developed to target multiple vaccine components to DCs. In this Perspective, we discuss the pros and cons of targeting DCs: if targeting is beneficial at all and which vaccine vehicles and immunization routes represent promising strategies to reach and activate DCs.

  15. Harnessing Dendritic Cells for Tumor Antigen Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Nierkens, Stefan [Department of Tumor Immunology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Geert Grooteplein 28, Nijmegen 6525 GA (Netherlands); Janssen, Edith M., E-mail: edith.janssen@cchmc.org [Division of Molecular Immunology, Cincinnati Children' s Hospital Research Foundation, University of Cincinnati College of Medicine, 3333 Burnet Avenue, Cincinnati, OH 45229 (United States)

    2011-04-26

    Dendritic cells (DC) are professional antigen presenting cells that are crucial for the induction of anti-tumor T cell responses. As a consequence, research has focused on the harnessing of DCs for therapeutic interventions. Although current strategies employing ex vivo-generated and tumor-antigen loaded DCs have been proven feasible, there are still many obstacles to overcome in order to improve clinical trial successes and offset the cost and complexity of customized cell therapy. This review focuses on one of these obstacles and a pivotal step for the priming of tumor-specific CD8{sup +} and CD4{sup +} T cells; the in vitro loading of DCs with tumor antigens.

  16. Photoinduced electron transfer between the dendritic zinc phthalocyanines and anthraquinone

    Science.gov (United States)

    Chen, Kuizhi; Wen, Junri; Liu, Jiangsheng; Chen, Zhenzhen; Pan, Sujuan; Huang, Zheng; Peng, Yiru

    2015-03-01

    The intermolecular electron transfer between the novel dendritic zinc (II) phthalocyanines (G1-DPcB and G2-DPcB) and anthraquinone (AQ) was studied by steady-state fluorescence and UV/Vis absorption spectroscopic methods. The effect of dendron generation on intermolecular electron transfer was investigated. The results showed that the fluorescence emission of these dendritic phthalocyanines could be greatly quenched by AQ upon excitation at 610 nm. The Stern- Volmer constant (KSV) of electron transfer was decreased with increasing the dendron generations. Our study suggested that these novel dendritic phthalocyanines were effective new electron donors and transmission complexes and could be used as a potential artifical photosysthesis system.

  17. Development of two distinct dendritic-like APCs in the context of splenic stroma

    Directory of Open Access Journals (Sweden)

    Pravin ePeriasamy

    2013-03-01

    Full Text Available Murine splenic stroma has been found to provide an in vitro niche for hematopoiesis of dendritic-like APCs (APC. Two distinct cell types have been characterised. The novel ‘L-DC’ subset, has cross presenting capacity leading to activation of CD8+ T cells, but do not activate CD4+ T cells consistent with their CD11cloCD11bhiMHC-II- phenotype. For L-DC, an equivalent tissue-specific APC has been found only in spleen. A second population of CD11chiCD11bloMHC-II+ cells resembling conventional dendritic cells (cDC can activate both CD4 and CD8 T cells. Production of L-DC but not cDC-like cells is now shown to be dependent on contact between the L-DC progenitor and stroma such that the presence of a Transwell membrane can prevent L-DC development. Since L-DC can be produced continuously in vitro in stromal co-cultures overlaid with bone marrow (BM progenitors, it was hypothesised that L-DC progenitors are self-renewing. The L-DC progenitor is shown here to be defined by the Flt3-c-kit+Lin-Sca-1+ (F-KLS subset of adult BM which contains primitive HSC. Since the less primitive F+KLS HSC subset also contains L-DC progenitors, Flt3 does not appear to be a defining marker for this progenitor. Precursors of the cDC-like subset are found only within the F+KLS subset and seed production of a transient population of APC. All data identify differentiation of L-DC from HSC, and of cDC-like cells from DC precursors, which occurs independently of inflammatory signals and is dependent on a splenic stromal microenvironment.

  18. Specific and Novel microRNAs Are Regulated as Response to Fungal Infection in Human Dendritic Cells

    Science.gov (United States)

    Dix, Andreas; Czakai, Kristin; Leonhardt, Ines; Schäferhoff, Karin; Bonin, Michael; Guthke, Reinhard; Einsele, Hermann; Kurzai, Oliver; Löffler, Jürgen; Linde, Jörg

    2017-01-01

    Within the last two decades, the incidence of invasive fungal infections has been significantly increased. They are characterized by high mortality rates and are often caused by Candida albicans and Aspergillus fumigatus. The increasing number of infections underlines the necessity for additional anti-fungal therapies, which require extended knowledge of gene regulations during fungal infection. MicroRNAs are regulators of important cellular processes, including the immune response. By analyzing their regulation and impact on target genes, novel therapeutic and diagnostic approaches may be developed. Here, we examine the role of microRNAs in human dendritic cells during fungal infection. Dendritic cells represent the bridge between the innate and the adaptive immune systems. Therefore, analysis of gene regulation of dendritic cells is of particular significance. By applying next-generation sequencing of small RNAs, we quantify microRNA expression in monocyte-derived dendritic cells after 6 and 12 h of infection with C. albicans and A. fumigatus as well as treatment with lipopolysaccharides (LPS). We identified 26 microRNAs that are differentially regulated after infection by the fungi or LPS. Three and five of them are specific for fungal infections after 6 and 12 h, respectively. We further validated interactions of miR-132-5p and miR-212-5p with immunological relevant target genes, such as FKBP1B, KLF4, and SPN, on both RNA and protein level. Our results indicate that these microRNAs fine-tune the expression of immune-related target genes during fungal infection. Beyond that, we identified previously undiscovered microRNAs. We validated three novel microRNAs via qRT-PCR. A comparison with known microRNAs revealed possible relations with the miR-378 family and miR-1260a/b for two of them, while the third one features a unique sequence with no resemblance to known microRNAs. In summary, this study analyzes the effect of known microRNAs in dendritic cells during

  19. Functional Characterization of a Gene in Sedum alfredii Hance Resembling Rubber Elongation Factor Endowed with Functions Associated with Cadmium Tolerance.

    Science.gov (United States)

    Liu, Mingying; Qiu, Wenming; He, Xuelian; Zheng, Liu; Song, Xixi; Han, Xiaojiao; Jiang, Jing; Qiao, Guirong; Sang, Jian; Liu, Mingqing; Zhuo, Renying

    2016-01-01

    Cadmium is a major toxic heavy-metal pollutant considering their bioaccumulation potential and persistence in the environment. The hyperaccumulating ecotype of Sedum alfredii Hance is a Zn/Cd co-hyperaccumulator inhabiting in a region of China with soils rich in Pb/Zn. Investigations into the underlying molecular regulatory mechanisms of Cd tolerance are of substantial interest. Here, library screening for genes related to cadmium tolerance identified a gene resembling the rubber elongation factor gene designated as SaREFl. The heterologous expression of SaREFl rescued the growth of a transformed Cd-sensitive strain (ycf1). Furthermore, SaREFl-expressing Arabidopsis plants were more tolerant to cadmium stress compared with wild type by measuring parameters of root length, fresh weight and physiological indexes. When under four different heavy metal treatments, we found that SaREFl responded most strongly to Cd and the root was the plant organ most sensitive to this heavy metal. Yeast two-hybrid screening of SaREFl as a bait led to the identification of five possible interacting targets in Sedum alfredii Hance. Among them, a gene annotated as prenylated Rab acceptor 1 (PRA1) domain protein was detected with a high frequency. Moreover, subcellular localization of SaREF1-GFP fusion protein revealed some patchy spots in cytosol suggesting potential association with organelles for its cellular functions. Our findings would further enrich the connotation of REF-like genes and provide theoretical assistance for the application in breeding heavy metal-tolerant plants.

  20. A simple approach to the synthesis of Cu1.8S dendrites with thiamine hydrochloride as a sulfur source and structure-directing agent

    Directory of Open Access Journals (Sweden)

    Xiaoliang Yan

    2015-04-01

    Full Text Available A facile, green and environmental-friendly method for preparing Cu1.8S dendrites was developed. Copper nitrate and thiamine hydrochloride were selected as the starting materials in the water phase under hydrothermal conditions. No addition of a surfactant or a complex reagent was required for the synthesis of the Cu1.8S dendrite structures. Thiamine hydrochloride was employed as a sulfur source and structure-directing agent. The growth mechanism of Cu1.8S is tentatively discussed based on the experimental and computational results.

  1. Molecule Matters-Dendritic Architecture-A Clever Route to ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 12; Issue 1. Molecule Matters - Dendritic Architecture - A Clever Route to Monodispersed Macromolecules. N Jayaraman. Feature Article Volume 12 Issue 1 January 2007 pp 60-66 ...

  2. Synthesis of novel starburst and dendritic polyhedral oligosilsesquioxanes.

    Science.gov (United States)

    Wada, Kenji; Watanabe, Naoki; Yamada, Koichi; Kondo, Teruyuki; Mitsudo, Take-aki

    2005-01-07

    The hydrosilylative reaction utilizing octakis(dimethylsiloxy)silsesquioxane and silsesquioxane disilanols bearing alkenylsilyl moieties produces a series of starburst-type giant silsesquioxanes and a second-generation dendritic molecule as well as a boron-containing one.

  3. Functional Compartmentalization within Starburst Amacrine Cell Dendrites in the Retina.

    Science.gov (United States)

    Poleg-Polsky, Alon; Ding, Huayu; Diamond, Jeffrey S

    2018-03-13

    Dendrites in many neurons actively compute information. In retinal starburst amacrine cells, transformations from synaptic input to output occur within individual dendrites and mediate direction selectivity, but directional signal fidelity at individual synaptic outputs and correlated activity among neighboring outputs on starburst dendrites have not been examined systematically. Here, we record visually evoked calcium signals simultaneously at many individual synaptic outputs within single starburst amacrine cells in mouse retina. We measure visual receptive fields of individual output synapses and show that small groups of outputs are functionally compartmentalized within starburst dendrites, creating distinct computational units. Inhibition enhances compartmentalization and directional tuning of individual outputs but also decreases the signal-to-noise ratio. Simulations suggest, however, that the noise underlying output signal variability is well tolerated by postsynaptic direction-selective ganglion cells, which integrate convergent inputs to acquire reliable directional information. Published by Elsevier Inc.

  4. Supramolecular effects in dendritic systems containing photoactive groups

    Directory of Open Access Journals (Sweden)

    GIANLUCA CAMILLO AZZELLINI

    2000-03-01

    Full Text Available In this article are described dendritic structures containing photoactive groups at the surface or in the core. The observed supramolecular effects can be attributed to the nature of the photoactive group and their location in the dendritic architecture. The peripheric azobenzene groups in these dendrimeric compounds can be regarded as single residues that retain the spectroscopic and photochemical properties of free azobenzene moiety. The E and Z forms of higher generation dendrimer, functionalized with azobenzene groups, show different host ability towards eosin dye, suggesting the possibility of using such dendrimer in photocontrolled host-guest systems. The photophysical properties of many dendritic-bipyridine ruthenium complexes have been investigated. Particularly in aerated medium more intense emission and a longer excited-state lifetime are observed as compared to the parent unsubstituted bipyridine ruthenium complexes. These differences can be attributed to a shielding effect towards dioxygen quenching originated by the dendritic branches.

  5. Use and abuse of dendritic cells by Toxoplasma gondii

    Science.gov (United States)

    Sanecka, Anna; Frickel, Eva-Maria

    2012-01-01

    The ubiquitous apicomplexan parasite Toxoplasma gondii stimulates its host’s immune response to achieve quiescent chronic infection. Central to this goal are host dendritic cells. The parasite exploits dendritic cells to disseminate through the body, produce pro-inflammatory cytokines, present its antigens to the immune system and yet at the same time subvert their signaling pathways in order to evade detection. This carefully struck balance by Toxoplasma makes it the most successful parasite on this planet. Recent progress has highlighted specific parasite and host molecules that mediate some of these processes particularly in dendritic cells and in other cells of the innate immune system. Critically, there are several important factors that need to be taken into consideration when concluding how the dendritic cells and the immune system deal with a Toxoplasma infection, including the route of administration, parasite strain and host genotype. PMID:23221473

  6. Dendritic biomimicry: microenvironmental hydrogen-bonding effects on tryptophan fluorescence.

    Science.gov (United States)

    Koenig, S; Müller, L; Smith, D K

    2001-03-02

    Two series of dendritically modified tryptophan derivatives have been synthesised and their emission spectra measured in a range of different solvents. This paper presents the syntheses of these novel dendritic structures and discusses their emission spectra in terms of both solvent and dendritic effects. In the first series of dendrimers, the NH group of the indole ring is available for hydrogen bonding, whilst in the second series, the indole NH group has been converted to NMe. Direct comparison of the emission wavelengths of analogous NH and NMe derivatives indicates the importance of the Kamlet-Taft solvent beta3 parameter, which reflects the ability of the solvent to accept a hydrogen bond from the NH group, an effect not possible for the NMe series of dendrimers. For the NH dendrimers, the attachment of a dendritic shell to the tryptophan subunit leads to a red shift in emission wavelength. This dendritic effect only operates in non-hydrogen-bonding solvents. For the NMe dendrimers, however, the attachment of a dendritic shell has no effect on the emission spectra of the indole ring. This proves the importance of hydrogen bonding between the branched shell and the indole NH group in causing the dendritic effect. This is the first time a dendritic effect has been unambiguously assigned to individual hydrogen-bonding interactions and indicates that such intramolecular interactions are important in dendrimers, just as they are in proteins. Furthermore, this paper sheds light on the use of tryptophan residues as a probe of the microenvironment within proteins--in particular, it stresses the importance of hydrogen bonds formed by the indole NH group.

  7. The chemoimmunotherapy based on dendritic cells and cisplatin in experiment

    OpenAIRE

    Gorbach, O.; Khranovska, N.; Skachkova, O.; Sydor, R.; Pozur, V.

    2014-01-01

    The aim of the study was to develop a scheme of combined chemoimmunotherapy and to investigate antitumor and immunomodulatory activity of chemoimmunotherapy regimen using the vaccine based on dendritic cells and low-doses of cisplatin in CBA mice with sarcoma-37. Maximal antitumor and immunomodulatory effects were observed after application of the vaccine based on dendritic cells in combination with doses of cisplatin concentration of 2 mg/kg. Among significant immunomodulatory effects of com...

  8. The dendritic cell niche in chronic obstructive pulmonary disease

    OpenAIRE

    Haczku, Angela

    2012-01-01

    Abstract The pulmonary innate immune system is heavily implicated in the perpetual airway inflammation and impaired host defense characterizing Chronic Obstructive Pulmonary Disease (COPD). The airways of patients suffering from COPD are infiltrated by various immune and inflammatory cells including macrophages, neutrophils, T lymphocytes, and dendritic cells. While the role of macrophages, neutrophils and T lymphocytes is well characterized, the contribution of dendritic cells to COPD pathog...

  9. Functional Compartmentalization within Starburst Amacrine Cell Dendrites in the Retina

    Directory of Open Access Journals (Sweden)

    Alon Poleg-Polsky

    2018-03-01

    Full Text Available Summary: Dendrites in many neurons actively compute information. In retinal starburst amacrine cells, transformations from synaptic input to output occur within individual dendrites and mediate direction selectivity, but directional signal fidelity at individual synaptic outputs and correlated activity among neighboring outputs on starburst dendrites have not been examined systematically. Here, we record visually evoked calcium signals simultaneously at many individual synaptic outputs within single starburst amacrine cells in mouse retina. We measure visual receptive fields of individual output synapses and show that small groups of outputs are functionally compartmentalized within starburst dendrites, creating distinct computational units. Inhibition enhances compartmentalization and directional tuning of individual outputs but also decreases the signal-to-noise ratio. Simulations suggest, however, that the noise underlying output signal variability is well tolerated by postsynaptic direction-selective ganglion cells, which integrate convergent inputs to acquire reliable directional information. : Poleg-Polsky et al. examine the directional signaling fidelity of individual synapses on starburst amacrine cell dendrites. They identify functionally and morphologically distinct signaling compartments within SAC dendrites and show that inhibition enhances reliable decoding by postsynaptic direction-selective ganglion cells. Keywords: retina, synaptic transmission, amacrine cell, correlation, visual processing, inhibition, direction selectivity

  10. Unc-51/ATG1 controls axonal and dendritic development via kinesin-mediated vesicle transport in the Drosophila brain.

    Directory of Open Access Journals (Sweden)

    Hiroaki Mochizuki

    2011-05-01

    Full Text Available Members of the evolutionary conserved Ser/Thr kinase Unc-51 family are key regulatory proteins that control neural development in both vertebrates and invertebrates. Previous studies have suggested diverse functions for the Unc-51 protein, including axonal elongation, growth cone guidance, and synaptic vesicle transport.In this work, we have investigated the functional significance of Unc-51-mediated vesicle transport in the development of complex brain structures in Drosophila. We show that Unc-51 preferentially accumulates in newly elongating axons of the mushroom body, a center of olfactory learning in flies. Mutations in unc-51 cause disintegration of the core of the developing mushroom body, with mislocalization of Fasciclin II (Fas II, an IgG-family cell adhesion molecule important for axonal guidance and fasciculation. In unc-51 mutants, Fas II accumulates in the cell bodies, calyx, and the proximal peduncle. Furthermore, we show that mutations in unc-51 cause aberrant overshooting of dendrites in the mushroom body and the antennal lobe. Loss of unc-51 function leads to marked accumulation of Rab5 and Golgi components, whereas the localization of dendrite-specific proteins, such as Down syndrome cell adhesion molecule (DSCAM and No distributive disjunction (Nod, remains unaltered. Genetic analyses of kinesin light chain (Klc and unc-51 double heterozygotes suggest the importance of kinesin-mediated membrane transport for axonal and dendritic development. Moreover, our data demonstrate that loss of Klc activity causes similar axonal and dendritic defects in mushroom body neurons, recapitulating the salient feature of the developmental abnormalities caused by unc-51 mutations.Unc-51 plays pivotal roles in the axonal and dendritic development of the Drosophila brain. Unc-51-mediated membrane vesicle transport is important in targeted localization of guidance molecules and organelles that regulate elongation and compartmentalization of

  11. Effect of facial self-resemblance on the startle response and subjective ratings of erotic stimuli in heterosexual men.

    Science.gov (United States)

    Lass-Hennemann, Johanna; Deuter, Christian E; Kuehl, Linn K; Schulz, Andre; Blumenthal, Terry D; Schachinger, Hartmut

    2011-10-01

    Cues of kinship are predicted to increase prosocial behavior due to the benefits of inclusive fitness, but to decrease approach motivation due to the potential costs of inbreeding. Previous studies have shown that facial resemblance, a putative cue of kinship, increases prosocial behavior. However, the effects of facial resemblance on mating preferences are equivocal, with some studies finding that facial resemblance decreases sexual attractiveness ratings, while other studies show that individuals choose mates partly on the basis of similarity. To further investigate this issue, a psychophysiological measure of affective processing, the startle response, was used in this study, assuming that differences in approach motivation to erotic pictures will modulate startle. Male volunteers (n = 30) viewed 30 pictures of erotic female nudes while startle eyeblink responses were elicited by acoustic noise probes. The female nude pictures were digitally altered so that the face either resembled the male participant or another participant, or were not altered. Non-nude neutral pictures were also included. Importantly, the digital alteration was undetected by the participants. Erotic pictures were rated as being pleasant and clearly reduced startle eyeblink magnitude as compared to neutral pictures. Participants showed greater startle inhibition to self-resembling than to other-resembling or non-manipulated female nude pictures, but subjective pleasure and arousal ratings did not differ among the three erotic picture categories. Our data suggest that visual facial resemblance of opposite-sex nudes increases approach motivation in men, and that this effect was not due to their conscious evaluation of the erotic stimuli.

  12. Dendritic cells recognize tumor-specific glycosylation of carcinoembryonic antigen on colorectal cancer cells through dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin

    NARCIS (Netherlands)

    van Gisbergen, Klaas P. J. M.; Aarnoudse, Corlien A.; Meijer, Gerrit A.; Geijtenbeek, Teunis B. H.; van Kooyk, Yvette

    2005-01-01

    Dendritic cells play a pivotal role in the induction of antitumor immune responses. Immature dendritic cells are located intratumorally within colorectal cancer and intimately interact with tumor cells, whereas mature dendritic cells are present peripheral to the tumor. The majority of colorectal

  13. Dendritic and axonic fields of Purkinje cells in developing and X-irradiated rat cerebellum. A comparative study using intracellular staining with horseradish peroxidase

    International Nuclear Information System (INIS)

    Crepel, F.; Delhaye-Bouchaud, N.; Dupont, J.L.; Sotelo, C.

    1980-01-01

    Intracellular staining of cerebellar Purkinje cells with horseradish peroxidase was achieved in normal developing rats (8-13 days old), in normal adult rats and in adult rats in which the cerebellum had been degranulated by X-ray treatment. The mono- and multiple innervation of Purkinje cells by climbing fibres was electrophysiologically determined and correlated with their dendritic pattern and axonal field. In immature rats, considerable variations in dendritic arborization were observed between cells at the same age, according to their position in the vermis. In adult X-irradiated animals, a large variety of dendritic shapes was found, confirming previous anatomical data, but no obvious correlation was found between the morphology of the dendrites of Purkinje cells and their synaptic investment by climbing fibres. As regards the axonal field, the adult branching pattern of recurrent axon collaterals was almost established by postnatal day 8, except for some cells which exhibited richer recurrent collaterals. On the other hand, in X-irradiated animals, profuse plexuses were the rule and they originated either from one collateral stem, or from several collaterals, also independently of the number of afferent climbing fibres. The existence of these enlarged recurrent collateral plexuses can be explained by the persistence of an immature stage, and certainly also by the collateral sprouting following the largely impaired innervation of the terminal field during development. These results emphasize the role of the cellular interactions that occur during Purkinje cell growth in the formation of both its axonal and dendritic fields. (author)

  14. Equine dendritic cells generated with horse serum have enhanced functionality in comparison to dendritic cells generated with fetal bovine serum

    OpenAIRE

    Ziegler, Anja; Everett, Helen; Hamza, Eman; Garbani, Mattia; Gerber, Vinzenz; Marti, Eliane; Steinbach, Falko

    2016-01-01

    BACKGROUND: Dendritic cells are professional antigen-presenting cells that play an essential role in the initiation and modulation of T cell responses. They have been studied widely for their potential clinical applications, but for clinical use to be successful, alternatives to xenogeneic substances like fetal bovine serum (FBS) in cell culture need to be found. Protocols for the generation of dendritic cells ex vivo from monocytes are well established for several species, including hor...

  15. Multiple modes of action potential initiation and propagation in mitral cell primary dendrite

    DEFF Research Database (Denmark)

    Chen, Wei R; Shen, Gongyu Y; Shepherd, Gordon M

    2002-01-01

    in the distal primary dendrite but failed to propagate to the soma. As the inhibition became weaker, a "double-spike" was often observed at the dendritic recording site, corresponding to a single action potential at the soma. Simulation demonstrated that, in the course of forward propagation of the first......-to-moderate olfactory nerve input, an action potential was initiated near the soma and then back-propagated into the primary dendrite. As olfactory nerve input increased, the initiation site suddenly shifted to the distal primary dendrite. Multi-compartmental modeling indicated that this abrupt shift of the spike...... dendritic spike, the action potential suddenly jumps from the middle of the dendrite to the axonal spike-initiation site, leaving the proximal part of primary dendrite unexcited by this initial dendritic spike. As Na(+) conductances in the proximal dendrite are not activated, they become available...

  16. Prion disease resembling frontotemporal dementia and parkinsonism linked to chromosome 17

    Directory of Open Access Journals (Sweden)

    Nitrini Ricardo

    2001-01-01

    Full Text Available OBJECTIVE: To compare the clinical features of a familial prion disease with those of frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17. BACKGROUND: Prion diseases are not usually considered in the differential diagnosis of FTDP-17, since familial Creutzfeldt-Jakob disease (CJD, the most common inherited prion disease, often manifests as a rapidly progressive dementia. Conversely, FTDP-17 usually has an insidious onset in the fifth decade, with abnormal behavior and parkinsonian features. METHOD: We present the clinical features of 12 patients from a family with CJD associated with a point mutation at codon 183 of the prion protein gene. RESULTS: The mean age at onset was 44.0 ± 3.7; the duration of the symptoms until death ranged from two to nine years. Behavioral disturbances were the predominant presenting symptoms. Nine patients were first seen by psychiatrists. Eight patients manifested parkinsonian signs. CONCLUSION: These clinical features bear a considerable resemblance to those described in FTDP-17.

  17. On Learning Natural-Science Categories That Violate the Family-Resemblance Principle.

    Science.gov (United States)

    Nosofsky, Robert M; Sanders, Craig A; Gerdom, Alex; Douglas, Bruce J; McDaniel, Mark A

    2017-01-01

    The general view in psychological science is that natural categories obey a coherent, family-resemblance principle. In this investigation, we documented an example of an important exception to this principle: Results of a multidimensional-scaling study of igneous, metamorphic, and sedimentary rocks (Experiment 1) suggested that the structure of these categories is disorganized and dispersed. This finding motivated us to explore what might be the optimal procedures for teaching dispersed categories, a goal that is likely critical to science education in general. Subjects in Experiment 2 learned to classify pictures of rocks into compact or dispersed high-level categories. One group learned the categories through focused high-level training, whereas a second group was required to simultaneously learn classifications at a subtype level. Although high-level training led to enhanced performance when the categories were compact, subtype training was better when the categories were dispersed. We provide an interpretation of the results in terms of an exemplar-memory model of category learning.

  18. Pulmonary Extramedullary Hematopoiesis in a Patient with Chronic Asthma Resembling Lung Cancer: A Case Report

    Directory of Open Access Journals (Sweden)

    Massood Hosseinzadeh

    2012-01-01

    Full Text Available Background. Extramedullary hematopoiesis is most often seen in reticuloendothelial organs specially spleen, liver, or lymph nodes, and it is rarely seen in lung parenchyma. Almost all reported cases of pulmonary extramedullary hematopoiesis occurred following myeloproliferative disorders specially myelofibrosis. Other less common underlying causes are thalassemia syndromes and other hemoglobinopathies. There was not any reported case of pulmonary extramedullary hematopoiesis in asthmatic patients in the medical literature. Case. Here we reported a 65-year-old lady who was a known case of bronchial asthma with recent developed right lower lobe lung mass. Chest X-ray and CT studies showed an infiltrating mass resembling malignancy. Fine needle aspiration cytology of mass revealed pulmonary extramedullary hematopoiesis. The patient followed for 10 months with serial physical examination and laboratory evaluations which were unremarkable. Conclusion. Extramedullary hematopoiesis of lung parenchyma can be mistaken for lung cancer radiologically. Although previous reported cases occurred with myelofibrosis or hemoglobinopathies, we are reporting the first case of asthma-associated extramedullary hematopoiesis.

  19. Nuclear security culture in comparison with nuclear safety culture. Resemblances and differences

    International Nuclear Information System (INIS)

    Kawata, Norio

    2015-01-01

    Since the terrorist attacks on the U.S. on September 11th, 2001, Nuclear Security has been focused on and treated as a global issue in the international community and it has also been discussed as a real and serious threat to nuclear power plants in the world since 'The Great East Japan Earthquake' in March, 2011. The International Atomic Energy Agency (IAEA) issued a document including Nuclear Security Recommendations (INFCIRC/225/Rev.5) (NSS 13) in the Nuclear Security Series and emphasized the necessity of fostering Nuclear Security Culture. Nuclear Security Culture has been frequently discussed at various kinds of seminars and events. Since the officials in charge of Nuclear Security are familiar with the area of Nuclear Safety, the relationships between Nuclear Safety Culture and Nuclear Security Culture have been the point in controversy. This paper clarifies relevance between Nuclear Safety and Security, considers resemblances and differences of their concepts and lessons learned for each culture from nuclear power plant accidents, and promotes deeper understanding of Nuclear Safety and Nuclear Security Culture. (author)

  20. Granular cell ameloblastoma: case report of a particular ameloblastoma histologically resembling oncocytoma.

    Science.gov (United States)

    Matsushita, Yuki; Fujita, Shuichi; Kawasaki, Goro; Hirota, Yoshinosuke; Rokutanda, Satoshi; Yamashita, Kentaro; Yanamoto, Souichi; Ikeda, Tohru; Umeda, Masahiro

    2015-01-01

    Granular cell ameloblastoma is classified as a histological subtype of solid/multicystic ameloblastoma. Usual granular cell ameloblastoma is histologically characterized by granular changes of stellate-like cells located in the inner portion of the epithelial follicles. Here we report a case of another type of granular cell ameloblastoma, showing predominant anastomosing double-stranded trabeculae of granular cells. This type of granular cell ameloblastoma is extremely rare, and the World Health Organization classification does not contain the entity. We tentatively termed it 'anastomosing granular cell ameloblastoma' in this report. The present case suggests the importance of differential diagnosis because the histology of 'anastomosing granular cell ameloblastoma' resembles that of salivary gland oncocytoma rather than that of usual granular cell ameloblastoma. The trabeculae observed in our case continued to the peripheral cells of a small amount of epithelial sheets of plexiform ameloblastoma, and the tumor cells were positive for CK19, which is regarded as an immunohistochemical marker of odontogenic epithelium. Similar to usual granular cell ameloblastoma, the tumor cells had CD68-positive granules. For precise diagnosis of this condition, immunohistochemistry using CK19 and CD68, as well as detailed histological observation, are recommended. © 2014 Japanese Society of Pathology and Wiley Publishing Asia Pty Ltd.

  1. Manganese Oxides Resembling Microbial Fabrics and Their Implications for Recognizing Inorganically Preserved Microfossils.

    Science.gov (United States)

    Muscente, A D; Czaja, Andrew D; Tuggle, James; Winkler, Christopher; Xiao, Shuhai

    2018-03-01

    In the search for microfossils of early life on Earth, the demonstration of biogenicity is paramount. Traditionally, only syngenetic structures with cellular elaboration, hollow sheaths/cell walls, and indigenous kerogen have been considered bona fide fossils. Recent reports of inorganically preserved microfossils represent a shift from this practice. Such a shift, if accompanied by a robust set of biogenicity criteria, could have profound implications for the identification of biosignatures on early Earth and extraterrestrial bodies. Here, we reaffirm the conventional criteria by examining aggregates of inorganic filaments from the Pilbara region of Western Australia. These aggregates are preserved in bedded chert, and the filaments measure up to 1 μm in diameter and 100 μm in length. The aggregates superficially resemble kerogenous microbial fabrics and mycelial organisms. However, the filaments consist of manganese oxide, lack cellular elaboration, and show no evidence for hollow sheaths or cell walls. We conclude that the filaments are fibrous minerals of abiotic origin. The similarities between these pseudofossils and some filamentous fossils highlight the need for strict application of the conventional criteria for recognizing microfossils. In the absence of kerogen, morphologically simple structures should, at least, show evidence of cellular features to be considered bona fide fossils. Key Words: Fossil-Manganese oxide-Pilbara-Precambrian-Pseudofossil. Astrobiology 18, 249-258.

  2. Ad-hoc KEEN-type Waves and their Occasional Resemblance to KdV Waveforms

    Science.gov (United States)

    Tyshetskiy, Yuriy; Afeyan, Bedros

    2005-10-01

    Nonlinear kinetic waves of the KEEN type [1] but constructed with two BGK recipes are tested with 1D Vlasov-Poisson simulation (1DVPS). One is that of Allis [2] as modified by Johnston (unpublished), the other is that of Eliasson and Shukla [3]. Strong kinetic waves survive well, but not weaker ones. The potential wave trains resemble those from the Korteweg-deVries equation. This proves to be natural when charge density variation with electrostatic potential is like a quadratic polynomial. For expositions on the physics of ponderomotively driven KEEN waves, consult presentations by Afeyan and Savchenko, this conference. (Part of this work was performed under the auspices of the U.S. Department of Energy under grant number DE-FG03-NA00059.) [1] B. Afeyan et al., ``Kinetic Electrostatic Electron Nonlinear (KEEN) Waves and their interactions driven by the ponderomotive force of crossing laser beams'', Proc. IFSA (Inertial Fusion Sciences and Applications 2003, Monterey, CA), 213, B. Hammel, D. Meyerhofer, J. Meyer-ter-Vehn and H. Azechi, editors, American Nuclear Society, 2004. [2] W.P. Allis, paper 3 (pp.21-42), in ``In Honor of Philip M. Morse'', ed. H. Feshbach and K. Ingard, MIT Press (1969). [3] B. Eliasson and P.K. Shukla, Phys. Rev. E 71, 046402 (2005)

  3. An unusual clinical presentation resembling superior vena cava syndrome post heart surgery

    Directory of Open Access Journals (Sweden)

    Pellegrini Ronald

    2005-10-01

    Full Text Available Abstract Background An unusual sequence of post operative events heralded by hemodynamic deterioration followed by dyspnea and rapidly progressive dilatation of superficial neck and facial veins, resembling a superior vena cava syndrome, two days post surgical resection of filamentous aortic valve masses, closure of a patent foramen ovale, and performance of a modified Maze procedure for atrial fibrillation in a patient that presented with transient neurologic findings is presented. Case Presentation Although both clinical findings and hemodynamic derangements completely resolved following tricuspid valve repair aimed to correct the new onset severe tricuspid regurgitation noted post operatively; a clear mechanism was not readily obvious and diagnostic testing data somewhat conflictive. We present a careful retrospective examination of all clinical data and review possible clinical entities that could have been implicated in this particular case and recognize that transesophageal echocardiographic findings were most useful in identifying the best course of action. Conclusion After reviewing all clinical data and despite the inconclusive nature of test results; the retrospective examination of transesophageal echocardiographic findings proved to be most useful in identifying the best course of action. We postulate that in our case, resolution of the suspected pulmonary embolism with anticoagulation and reestablishment of a normal right ventricular geometry with tricuspid valve repair worked in unison in restoring normal hemodynamics and resolving both dyspnea and venous dilatation.

  4. Phenotype-genotype discordance in congenital malformations with communication disorders resembling trisomy 18 (Edwards syndrome)

    Science.gov (United States)

    Pruszewicz, Antoni; Wiskirska-Woźnica, Bożena; Wojnowski, Waldemar; Czerniejewska, Hanna; Jackowska, Joanna; Jarmuż, Małgorzata; Szyfter, Krzysztof; Leszczyńska, Małgorzata

    2014-01-01

    Patient: Female, 6 Final Diagnosis: Phenotype-genotype discordance in congenital malformations with communication disorders resembling trisomy 18 (Edwards syndrome) Symptoms: — Medication: — Clinical Procedure: — Specialty: Otolaryngology Objective: Congenital defects Background: Communication process disorders are very frequent in rare cases of chromosomal aberrations (deletions, insertions, and trisomies) such as Down syndrome (trisomy 21), Turner syndrome, Edwards syndrome (trisomy 18), or Patau syndrome (trisomy 13). Sometimes phenotype may delusively correspond to the characteristic features of a given syndrome, but genotype tests do not confirm its presence. Case Report: We present the case of a 6-year-old girl admitted to the Clinic of Phoniatrics and Audiology for the assessment of communication in the course of congenital malformations with phenotype characteristic for trisomy 18 (Edwards syndrome). Immediately upon birth, dysmorphic changes suggesting trisomy 18 (Edwards syndrome) were observed, but trisomy 18 was excluded after karyotype test results were normal (46, XX). Conclusions: Disturbed articulation was diagnosed: deformed linguo-dental and palatal sounds, interdental realization with flat tongue of the /s/, /z/, /c/, /dz/, /ś/, /ź/, /ć/, /dz/ sounds (sigmatismus interdentalis). Hearing loss was confirmed. PMID:24478819

  5. Phenotype-genotype discordance in congenital malformations with communication disorders resembling trisomy 18 (Edwards syndrome).

    Science.gov (United States)

    Pruszewicz, Antoni; Wiskirska-Woźnica, Bożena; Wojnowski, Waldemar; Czerniejewska, Hanna; Jackowska, Joanna; Jarmuż, Małgorzata; Szyfter, Krzysztof; Leszczyńska, Małgorzata

    2014-01-01

    Female, 6 FINAL DIAGNOSIS: Phenotype-genotype discordance in congenital malformations with communication disorders resembling trisomy 18 (Edwards syndrome) Symptoms: - - Clinical Procedure: - Specialty: Otolaryngology. Congenital defects. Communication process disorders are very frequent in rare cases of chromosomal aberrations (deletions, insertions, and trisomies) such as Down syndrome (trisomy 21), Turner syndrome, Edwards syndrome (trisomy 18), or Patau syndrome (trisomy 13). Sometimes phenotype may delusively correspond to the characteristic features of a given syndrome, but genotype tests do not confirm its presence. We present the case of a 6-year-old girl admitted to the Clinic of Phoniatrics and Audiology for the assessment of communication in the course of congenital malformations with phenotype characteristic for trisomy 18 (Edwards syndrome). Immediately upon birth, dysmorphic changes suggesting trisomy 18 (Edwards syndrome) were observed, but trisomy 18 was excluded after karyotype test results were normal (46, XX). DISTURBED ARTICULATION WAS DIAGNOSED: deformed linguo-dental and palatal sounds, interdental realization with flat tongue of the /s/, /z/, /c/, /dz/, /ś/, /ź/, /ć/, /dz/ sounds (sigmatismus interdentalis). Hearing loss was confirmed.

  6. The MacBlue Binary Transgene (csf1r-gal4VP16/UAS-ECFP) Provides a Novel Marker for Visualisation of Subsets of Monocytes, Macrophages and Dendritic Cells and Responsiveness to CSF1 Administration

    Science.gov (United States)

    Sehgal, Anuj; Bain, Calum C.; Scott, Charlotte; Moffat, Lindsey; Rojo, Rocío; Stutchfield, Ben M.; Davies, Claire L.; Donaldson, David S.; Renault, Kathleen; McColl, Barry W.; Mowat, Alan M.; Serrels, Alan; Frame, Margaret C.; Mabbott, Neil A.; Hume, David A.

    2014-01-01

    The MacBlue transgenic mouse uses the Csf1r promoter and first intron to drive expression of gal4-VP16, which in turn drives a cointegrated gal4-responsive UAS-ECFP cassette. The Csf1r promoter region used contains a deletion of a 150 bp conserved region covering trophoblast and osteoclast-specific transcription start sites. In this study, we examined expression of the transgene in embryos and adult mice. In embryos, ECFP was expressed in the large majority of macrophages derived from the yolk sac, and as the liver became a major site of monocytopoiesis. In adults, ECFP was detected at high levels in both Ly6C+ and Ly6C- monocytes and distinguished them from Ly6C+, F4/80+, CSF1R+ immature myeloid cells in peripheral blood. ECFP was also detected in the large majority of microglia and Langerhans cells. However, expression was lost from the majority of tissue macrophages, including Kupffer cells in the liver and F4/80+ macrophages of the lung, kidney, spleen and intestine. The small numbers of positive cells isolated from the liver resembled blood monocytes. In the gut, ECFP+ cells were identified primarily as classical dendritic cells or blood monocytes in disaggregated cell preparations. Immunohistochemistry showed large numbers of ECFP+ cells in the Peyer's patch and isolated lymphoid follicles. The MacBlue transgene was used to investigate the effect of treatment with CSF1-Fc, a form of the growth factor with longer half-life and efficacy. CSF1-Fc massively expanded both the immature myeloid cell (ECFP−) and Ly6C+ monocyte populations, but had a smaller effect on Ly6C− monocytes. There were proportional increases in ECFP+ cells detected in lung and liver, consistent with monocyte infiltration, but no generation of ECFP+ Kupffer cells. In the gut, there was selective infiltration of large numbers of cells into the lamina propria and Peyer's patches. We discuss the use of the MacBlue transgene as a marker of monocyte/macrophage/dendritic cell differentiation

  7. The MacBlue binary transgene (csf1r-gal4VP16/UAS-ECFP) provides a novel marker for visualisation of subsets of monocytes, macrophages and dendritic cells and responsiveness to CSF1 administration.

    Science.gov (United States)

    Sauter, Kristin A; Pridans, Clare; Sehgal, Anuj; Bain, Calum C; Scott, Charlotte; Moffat, Lindsey; Rojo, Rocío; Stutchfield, Ben M; Davies, Claire L; Donaldson, David S; Renault, Kathleen; McColl, Barry W; Mowat, Alan M; Serrels, Alan; Frame, Margaret C; Mabbott, Neil A; Hume, David A

    2014-01-01

    The MacBlue transgenic mouse uses the Csf1r promoter and first intron to drive expression of gal4-VP16, which in turn drives a cointegrated gal4-responsive UAS-ECFP cassette. The Csf1r promoter region used contains a deletion of a 150 bp conserved region covering trophoblast and osteoclast-specific transcription start sites. In this study, we examined expression of the transgene in embryos and adult mice. In embryos, ECFP was expressed in the large majority of macrophages derived from the yolk sac, and as the liver became a major site of monocytopoiesis. In adults, ECFP was detected at high levels in both Ly6C+ and Ly6C- monocytes and distinguished them from Ly6C+, F4/80+, CSF1R+ immature myeloid cells in peripheral blood. ECFP was also detected in the large majority of microglia and Langerhans cells. However, expression was lost from the majority of tissue macrophages, including Kupffer cells in the liver and F4/80+ macrophages of the lung, kidney, spleen and intestine. The small numbers of positive cells isolated from the liver resembled blood monocytes. In the gut, ECFP+ cells were identified primarily as classical dendritic cells or blood monocytes in disaggregated cell preparations. Immunohistochemistry showed large numbers of ECFP+ cells in the Peyer's patch and isolated lymphoid follicles. The MacBlue transgene was used to investigate the effect of treatment with CSF1-Fc, a form of the growth factor with longer half-life and efficacy. CSF1-Fc massively expanded both the immature myeloid cell (ECFP-) and Ly6C+ monocyte populations, but had a smaller effect on Ly6C- monocytes. There were proportional increases in ECFP+ cells detected in lung and liver, consistent with monocyte infiltration, but no generation of ECFP+ Kupffer cells. In the gut, there was selective infiltration of large numbers of cells into the lamina propria and Peyer's patches. We discuss the use of the MacBlue transgene as a marker of monocyte/macrophage/dendritic cell differentiation.

  8. Cecum lymph node dendritic cells harbor slow-growing bacteria phenotypically tolerant to antibiotic treatment.

    Directory of Open Access Journals (Sweden)

    Patrick Kaiser

    2014-02-01

    Full Text Available In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN, the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%-20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103⁺CX₃CR1⁻CD11c⁺ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics.

  9. Cecum Lymph Node Dendritic Cells Harbor Slow-Growing Bacteria Phenotypically Tolerant to Antibiotic Treatment

    Science.gov (United States)

    Dolowschiak, Tamas; Wotzka, Sandra Y.; Lengefeld, Jette; Slack, Emma; Grant, Andrew J.; Ackermann, Martin; Hardt, Wolf-Dietrich

    2014-01-01

    In vivo, antibiotics are often much less efficient than ex vivo and relapses can occur. The reasons for poor in vivo activity are still not completely understood. We have studied the fluoroquinolone antibiotic ciprofloxacin in an animal model for complicated Salmonellosis. High-dose ciprofloxacin treatment efficiently reduced pathogen loads in feces and most organs. However, the cecum draining lymph node (cLN), the gut tissue, and the spleen retained surviving bacteria. In cLN, approximately 10%–20% of the bacteria remained viable. These phenotypically tolerant bacteria lodged mostly within CD103+CX3CR1−CD11c+ dendritic cells, remained genetically susceptible to ciprofloxacin, were sufficient to reinitiate infection after the end of the therapy, and displayed an extremely slow growth rate, as shown by mathematical analysis of infections with mixed inocula and segregative plasmid experiments. The slow growth was sufficient to explain recalcitrance to antibiotics treatment. Therefore, slow-growing antibiotic-tolerant bacteria lodged within dendritic cells can explain poor in vivo antibiotic activity and relapse. Administration of LPS or CpG, known elicitors of innate immune defense, reduced the loads of tolerant bacteria. Thus, manipulating innate immunity may augment the in vivo activity of antibiotics. PMID:24558351

  10. Directed growth of diameter-tunable nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, Birol; Talukdar, Ishan; Flanders, Bret N [Department of Physics, Oklahoma State University, 145 Physical Sciences II, Stillwater, OK 74078 (United States)

    2007-09-12

    This study characterizes a method for controlling the nanowire diameter in the directed electrochemical nanowire assembly technique, where alternating voltages applied to electrodes in simple salt solutions induce the crystallization of metallic wires. Dendritic solidification is identified as an important component of this technique. A characteristic of dendritic solidification is that the growth velocity and tip radius are anti-correlated. This relationship is exploited here to realize diameter-tunable nanowire growth. The experimental parameter that provides this control is {omega}, the frequency of the alternating voltage. Increasing {omega} effectively steepens the metal cation concentration gradient at the wire-solution interface, thereby increasing the growth velocity of the wire. For indium wires, increasing {omega} from 0.5 to 3.5 MHz increases their growth velocity from 11 to 78 {mu}m s{sup -1} and reduces their diameter from 770 to 114 nm. Gold wires exhibit diameter-tunability that ranges from 150 nm to 45 nm. Thus, it is possible to tune the wire diameter from the microscale down to the nanoscale. Moreover, this control is a consequence of non-stationary dendritic growth, which distinguishes this process from most previously studied examples of dendritic solidification.

  11. Stochastic hybrid model of spontaneous dendritic NMDA spikes

    International Nuclear Information System (INIS)

    Bressloff, Paul C; Newby, Jay M

    2014-01-01

    Following recent advances in imaging techniques and methods of dendritic stimulation, active voltage spikes have been observed in thin dendritic branches of excitatory pyramidal neurons, where the majority of synapses occur. The generation of these dendritic spikes involves both Na + ion channels and M-methyl-D-aspartate receptor (NMDAR) channels. During strong stimulation of a thin dendrite, the resulting high levels of glutamate, the main excitatory neurotransmitter in the central nervous system and an NMDA agonist, modify the current-voltage (I–V) characteristics of an NMDAR so that it behaves like a voltage-gated Na + channel. Hence, the NMDARs can fire a regenerative dendritic spike, just as Na + channels support the initiation of an action potential following membrane depolarization. However, the duration of the dendritic spike is of the order 100 ms rather than 1 ms, since it involves slow unbinding of glutamate from NMDARs rather than activation of hyperpolarizing K + channels. It has been suggested that dendritic NMDA spikes may play an important role in dendritic computations and provide a cellular substrate for short-term memory. In this paper, we consider a stochastic, conductance-based model of dendritic NMDA spikes, in which the noise originates from the stochastic opening and closing of a finite number of Na + and NMDA receptor ion channels. The resulting model takes the form of a stochastic hybrid system, in which membrane voltage evolves according to a piecewise deterministic dynamics that is coupled to a jump Markov process describing the opening and closing of the ion channels. We formulate the noise-induced initiation and termination of a dendritic spike in terms of a first-passage time problem, under the assumption that glutamate unbinding is negligible, which we then solve using a combination of WKB methods and singular perturbation theory. Using a stochastic phase-plane analysis we then extend our analysis to take proper account of the

  12. Histamine regulates murine primary dendritic cell functions.

    Science.gov (United States)

    Schenk, Heiko; Neumann, Detlef; Kloth, Christina

    2016-10-01

    The modulation of antigen uptake and activation of dendritic cells (DCs) by histamine may function as a regulator of inflammation. Therefore, we sought to determine the impact of histamine on antigen uptake by and activation of murine DCs. DCs from spleen and lung were either identified by flow cytometry or were immunomagnetically enriched. Cells were stimulated with histamine, and the regulation of MHC-II and co-stimulatory molecule expression (CD80, CD86, and ICOS-L) and antigen uptake were quantified by flow cytometry. Individual contributions of the histamine receptor subtypes were determined by using the antagonists mepyramine (histamine H1-receptor: H1R), famotidine (H2R), and JNJ 7777120 (H4R). Histamine accelerated the uptake of soluble antigen via the H1R, H2R, and H4R in splenic DCs. Co-stimulatory molecule expression was enhanced already by enrichment procedures, thus, the analyses were performed in unseparated cell populations. Histamine enhanced the expression of CD86 and ICOS-L while expression of CD80 was unaffected. Antagonism at H1R, H2R, and H4R and at H1R and H4R reduced the histamine-induced enhanced expression of CD86 and ICOS-L, respectively. Histamine contributes to the regulation of the immunological synapse by stimulation of antigen uptake and activation of DCs via H1R, H2R, and H4R.

  13. The role of dendritic cells in cancer

    DEFF Research Database (Denmark)

    Hansen, Morten; Andersen, Mads Hald

    2017-01-01

    Though present in low numbers, dendritic cells (DCs) are recognized as major players in the control of cancer by adaptive immunity. The roles of cytotoxic CD8+ T-cells and Th1 helper CD4+ T-cells are well-documented in murine models of cancer and associated with a profound prognostic impact when...... infiltrating human tumors, but less information is known about how these T-cells gain access to the tumor or how they are primed to become tumor-specific. Here, we highlight recent findings that demonstrate a vital role of CD103+ DCs, which have been shown to be experts in cross-priming and the induction...... of anti-tumor immunity. We also focus on two different mediators that impair the function of tumor-associated DCs: prostaglandin E2 and β-catenin. Both of these mediators seem to be important for the exclusion of T-cells in the tumor microenvironment and may represent key pathways to target in optimized...

  14. Deciphering dendritic cell heterogenity in immunity

    Directory of Open Access Journals (Sweden)

    Michaël eChopin

    2012-02-01

    Full Text Available Dendritic cells (DCs are specialized antigen presenting cells that are exquisitely adapted to sense pathogens and induce the development of adaptive immune responses. They form a complex network of phenotypically and functionally distinct subsets. Within this network, individual DC subsets display highly specific roles in local immunosurveillance, migration and antigen presentation. This division of labor amongst DCs offers great potential to tune the immune response by harnessing subset-specific attributes of DCs in the clinical setting. Until recently, our understanding of DC subsets has been limited and paralleled by poor clinical translation and efficacy. We have now begun to unravel how different DC subsets develop within a complex multilayered system. These finding open up exciting possibilities for targeted manipulation of DC subsets. Furthermore, ground-breaking developments overcoming a major translational obstacle – identification of similar DC populations in mouse and man – now set the stage for significant advances in the field. Here we explore the determinants that underpin cellular and transcriptional heterogeneity within the DC network, how these influence DC distribution and localization at steady-state, and the capacity of DCs to present antigens via direct or cross-presentation during pathogen infection.

  15. Murine Cytomegalovirus Spreads by Dendritic Cell Recirculation

    Directory of Open Access Journals (Sweden)

    Helen E. Farrell

    2017-10-01

    Full Text Available Herpesviruses have coevolved with their hosts over hundreds of millions of years and exploit fundamental features of their biology. Cytomegaloviruses (CMVs colonize blood-borne myeloid cells, and it has been hypothesized that systemic dissemination arises from infected stem cells in bone marrow. However, poor CMV transfer by stem cell transplantation argues against this being the main reservoir. To identify alternative pathways for CMV spread, we tracked murine CMV (MCMV colonization after mucosal entry. We show that following intranasal MCMV infection, lung CD11c+ dendritic cells (DC migrated sequentially to lymph nodes (LN, blood, and then salivary glands. Replication-deficient virus followed the same route, and thus, DC infected peripherally traversed LN to enter the blood. Given that DC are thought to die locally following their arrival and integration into LN, recirculation into blood represents a new pathway. We examined host and viral factors that facilitated this LN traverse. We show that MCMV-infected DC exited LN by a distinct route to lymphocytes, entering high endothelial venules and bypassing the efferent lymph. LN exit required CD44 and the viral M33 chemokine receptor, without which infected DC accumulated in LN and systemic spread was greatly reduced. Taken together, our studies provide the first demonstration of virus-driven DC recirculation. As viruses follow host-defined pathways, high endothelial venules may normally allow DC to pass from LN back into blood.

  16. Crosstalk between T lymphocytes and dendritic cells.

    Science.gov (United States)

    Hivroz, Claire; Chemin, Karine; Tourret, Marie; Bohineust, Armelle

    2012-01-01

    Dendritic cells (DCs) are professional antigen-presenting cells (APCs) with the unique property of inducing priming and differentiation of naïve CD4+ and CD8+ T cells into helper and cytotoxic effectors. Their efficiency is due to their unique ability to process antigen, express costimulatory molecules, secrete cytokines, and migrate to tissues or lymphoid organs to prime T cells. DCs also play an important role in T-cell peripheral tolerance. There is ample evidence that the DC ability to present antigens is regulated by CD4+ helper T cells. Indeed, interactions between surface receptors and ligands expressed respectively by T cells and DCs, as well as T-cell-derived cytokines modify DC functions. This T-cell-induced modification of DCs has been called "education" or "licensing." This intimate crosstalk between DCs and T lymphocytes is key in establishing appropriate adaptive immune responses. It requires cognate interactions between T lymphocytes and DCs, which are organized in time and space by structures called immunological synapses. Here we discuss the particular aspects of immunological synapses formed between T cells and DCs and the role these organized interactions have in T-cell-DC crosstalk.

  17. [Natural killer cells complot with dendritic cells].

    Science.gov (United States)

    Bielawska-Pohl, Aleksandra; Pajtasz-Piasecka, Elżbieta; Duś, Danuta

    2013-03-18

    Dendritic cells (DC) were initially considered as antigen presenting cells participating in the polarization of the immune response. Further understanding of their biology allowed determining their additional functions such as immunoregulatory and cytotoxicity. Until recently natural killer (NK) cells were known as a homogeneous population of lymphocytes capable of non-specific recognizing and eliminating target cells. Now it is widely accepted that NK cells, as a heterogeneous population, may also possess immunomodulatory functions. Moreover, the most recent analysis of the interactions between DC and NK cells revealed the exceptional functions of these cells. As a result of these studies the existence of bitypic cell population was postulated. The distinguishing features of these hybrid cells are: the expression of surface receptors typical for NK cells and DC, the cytotoxic activity, the production of interferons as well as their ability to present antigen after prior stimulation. Despite the lack of strong direct evidence that the same cell can be both cytotoxic and effectively present the antigen at the same time, there are experimental findings suggesting that generated ex vivo bitypic cells may be used in antitumor therapy. 

  18. New generation of dendritic cell vaccines.

    Science.gov (United States)

    Radford, Kristen J; Caminschi, Irina

    2013-02-01

    Dendritic cells (DC) play a pivotal role in the induction and regulation of immune responses, including the induction of cytotoxic T lymphocytes (CTL) responses. These are essential for the eradication of cancers and pathogens including HIV and malaria, for which there are currently no effective vaccines. New developments in our understanding of DC biology have identified the key DC subset responsible for CTL induction, which is now an attractive candidate to target for vaccination. These DC are characterized by expression of novel markers Clec9A and XCR1, and a specialized capacity to cross-present antigen (Ag) from tumors and pathogens that do not directly infect DC. New generation DC vaccines that specifically target the cross-presenting DC in vivo have already demonstrated potential in preclinical animal models but the challenge remains to translate these findings into clinically efficacous vaccines in man. This has been greatly facilitated by the recent identification of the equivalent Clec9A(+) XCR1(+) cross-presenting DC in human lymphoid tissues and peripheral tissues that are key sites for vaccination administration. These findings combined with further studies on DC subset biology have important implications for the design of new CTL-mediated vaccines.

  19. Dendritic spine changes associated with normal aging.

    Science.gov (United States)

    Dickstein, D L; Weaver, C M; Luebke, J I; Hof, P R

    2013-10-22

    Given the rapid rate of population aging and the increased incidence of cognitive decline and neurodegenerative diseases with advanced age, it is important to ascertain the determinants that result in cognitive impairment. It is also important to note that much of the aged population exhibit 'successful' cognitive aging, in which cognitive impairment is minimal. One main goal of normal aging studies is to distinguish the neural changes that occur in unsuccessful (functionally impaired) subjects from those of successful (functionally unimpaired) subjects. In this review, we present some of the structural adaptations that neurons and spines undergo throughout normal aging and discuss their likely contributions to electrophysiological properties and cognition. Structural changes of neurons and dendritic spines during aging, and the functional consequences of such changes, remain poorly understood. Elucidating the structural and functional synaptic age-related changes that lead to cognitive impairment may lead to the development of drug treatments that can restore or protect neural circuits and mediate cognition and successful aging. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  20. 3D Fiber-Network-Reinforced Bicontinuous Composite Solid Electrolyte for Dendrite-free Lithium Metal Batteries.

    Science.gov (United States)

    Li, Dan; Chen, Long; Wang, Tianshi; Fan, Li-Zhen

    2018-02-28

    Replacement of flammable organic liquid electrolytes with solid Li + conductors is a promising approach to realize excellent performance of Li metal batteries. However, ceramic electrolytes are either easily reduced by Li metal or penetrated by Li dendrites through their grain boundaries, and polymer electrolytes are also faced with instability on the electrode/electrolyte interface and weak mechanical property. Here, we report a three-dimensional fiber-network-reinforced bicontinuous solid composite electrolyte with flexible Li + -conductive network (lithium aluminum titanium phosphate (LATP)/polyacrylonitrile), which helps to enhance electrochemical stability on the electrode/electrolyte interface by isolating Li and LATP and suppress Li dendrites growth by mechanical reinforcement of fiber network for the composite solid electrolyte. The composite electrolyte shows an excellent electrochemical stability after 15 days of contact with Li metal and has an enlarged tensile strength (10.72 MPa) compared to the pure poly(ethylene oxide)-bistrifluoromethanesulfonimide lithium salt electrolyte, leading to a long-term stability and safety of the Li symmetric battery with a current density of 0.3 mA cm -2 for 400 h. In addition, the composite electrolyte also shows good electrochemical and thermal stability. These results provide such fiber-reinforced membranes that present stable electrode/electrolyte interface and suppress lithium dendrite growth for high-safety all-solid-state Li metal batteries.

  1. Household and familial resemblance in risk factors for type 2 diabetes and related cardiometabolic diseases in rural Uganda sample

    DEFF Research Database (Denmark)

    Nielsen, Jannie; Bahendeka, Silver K.; Whyte, Susan R.

    2017-01-01

    (ICC=0.24), HbA1c (ICC=0.18) and systolic blood pressure (ICC=0.11). Regarding dyadic resemblance, the highest standardised regression coefficient was seen in fitness status for spouses (0.54, 95% CI 0.32 to 0.76), parent–offspring (0.41, 95% CI 0.28 0.54) and siblings (0.41, 95% CI 0.25 to 0.......57). Overall, parent–offspring and sibling pairs were the dyads with strongest resemblance, followed by spouses. Conclusions The marked degree of resemblance in T2D risk factors at household level and between spouses, parent–offspring and sibling dyads suggest that shared behavioural and environmental factors...

  2. Mitotic motors coregulate microtubule patterns in axons and dendrites.

    Science.gov (United States)

    Lin, Shen; Liu, Mei; Mozgova, Olga I; Yu, Wenqian; Baas, Peter W

    2012-10-03

    Microtubules are nearly uniformly oriented in the axons of vertebrate neurons but are non-uniformly oriented in their dendrites. Studies to date suggest a scenario for establishing these microtubule patterns whereby microtubules are transported into the axon and nascent dendrites with plus-ends-leading, and then additional microtubules of the opposite orientation are transported into the developing dendrites. Here, we used contemporary tools to confirm that depletion of kinesin-6 (also called CHO1/MKLP1 or kif23) from rat sympathetic neurons causes a reduction in the appearance of minus-end-distal microtubules in developing dendrites, which in turn causes them to assume an axon-like morphology. Interestingly, we observed a similar phenomenon when we depleted kinesin-12 (also called kif15 or HKLP2). Both motors are best known for their participation in mitosis in other cell types, and both are enriched in the cell body and dendrites of neurons. Unlike kinesin-12, which is present throughout the neuron, kinesin-6 is barely detectable in the axon. Accordingly, depletion of kinesin-6, unlike depletion of kinesin-12, has no effect on axonal branching or navigation. Interestingly, depletion of either motor results in faster growing axons with greater numbers of mobile microtubules. Based on these observations, we posit a model whereby these two motors generate forces that attenuate the transport of microtubules with plus-ends-leading from the cell body into the axon. Some of these microtubules are not only prevented from moving into the axon but are driven with minus-ends-leading into developing dendrites. In this manner, these so-called "mitotic" motors coregulate the microtubule patterns of axons and dendrites.

  3. Characterization of dendritic cells subpopulations in skin and afferent lymph in the swine model.

    Directory of Open Access Journals (Sweden)

    Florian Marquet

    Full Text Available Transcutaneous delivery of vaccines to specific skin dendritic cells (DC subsets is foreseen as a promising strategy to induce strong and specific types of immune responses such as tolerance, cytotoxicity or humoral immunity. Because of striking histological similarities between human and pig skin, pig is recognized as the most suitable model to study the cutaneous delivery of medicine. Therefore improving the knowledge on swine skin DC subsets would be highly valuable to the skin vaccine field. In this study, we showed that pig skin DC comprise the classical epidermal langerhans cells (LC and dermal DC (DDC that could be divided in 3 subsets according to their phenotypes: (1 the CD163(neg/CD172a(neg, (2 the CD163(highCD172a(pos and (3 the CD163(lowCD172a(pos DDC. These subtypes have the capacity to migrate from skin to lymph node since we detected them in pseudo-afferent lymph. Extensive phenotyping with a set of markers suggested that the CD163(high DDC resemble the antibody response-inducing human skin DC/macrophages whereas the CD163(negCD172(low DDC share properties with the CD8(+ T cell response-inducing murine skin CD103(pos DC. This work, by showing similarities between human, mouse and swine skin DC, establishes pig as a model of choice for the development of transcutaneous immunisation strategies targeting DC.

  4. Parent–offspring resemblance in colony-specific adult survival of cliff swallows

    Science.gov (United States)

    Brown, Charles R.; Roche, Erin A.; Brown, Mary Bomberger

    2015-01-01

    Survival is a key component of fitness. Species that occupy discrete breeding colonies with different characteristics are often exposed to varying costs and benefits associated with group size or environmental conditions, and survival is an integrative net measure of these effects. We investigated the extent to which survival probability of adult (≥1-year old) cliff swallows (Petrochelidon pyrrhonota) occupying different colonies resembled that of their parental cohort and thus whether the natal colony had long-term effects on individuals. Individuals were cross-fostered between colonies soon after hatching and their presence as breeders monitored at colonies in the western Nebraska study area for the subsequent decade. Colony-specific adult survival probabilities of offspring born and reared in the same colony, and those cross-fostered away from their natal colony soon after birth, were positively and significantly related to subsequent adult survival of the parental cohort from the natal colony. This result held when controlling for the effect of natal colony size and the age composition of the parental cohort. In contrast, colony-specific adult survival of offspring cross-fostered to a site was unrelated to that of their foster parent cohort or to the cohort of non-fostered offspring with whom they were reared. Adult survival at a colony varied inversely with fecundity, as measured by mean brood size, providing evidence for a survival–fecundity trade-off in this species. The results suggest some heritable variation in adult survival, likely maintained by negative correlations between fitness components. The study provides additional evidence that colonies represent non-random collections of individuals.

  5. Image and Global Resemblance in the Light of Hadith “Who So Imitates other People Becomes One of Them”

    Directory of Open Access Journals (Sweden)

    SERDAR DEMİREL

    2016-06-01

    Full Text Available In today’s world, people from different countries, cities and institutions unprecedentedly resemble each other in every aspect of life. Likewise, the deeds and imagery aspirations of Oriental and Occidental people also resemble. In such an atmosphere, the local cultures rooted in history become accessories and lose their historical significance and metaphysical aspects in the edifice of the society. This study aims to analyze Prophet Muhammad’s (s.a.w. warning, “Who so imitates other people becomes one of them”, its layers of meaning and its relationship with “image and global resemblence”.

  6. JNK1 Controls Dendritic Field Size in L2/3 and L5 of the Motor Cortex, Constrains Soma Size and Influences Fine Motor Coordination

    Directory of Open Access Journals (Sweden)

    Emilia eKomulainen

    2014-09-01

    Full Text Available Genetic anomalies on the JNK pathway confer susceptibility to autism spectrum disorders, schizophrenia and intellectual disability. The mechanism whereby a gain or loss of function in JNK signaling predisposes to these prevalent dendrite disorders, with associated motor dysfunction, remains unclear. Here we find that JNK1 regulates the dendritic field of L2/3 and L5 pyramidal neurons of the mouse motor cortex (M1, the main excitatory pathway controlling voluntary movement. In Jnk1-/- mice, basal dendrite branching of L5 pyramidal neurons is increased in M1, as is cell soma size, whereas in L2/3, dendritic arborization is decreased. We show that JNK1 phosphorylates rat HMW-MAP2 on T1619, T1622 and T1625 (Uniprot P15146 corresponding to mouse T1617, T1620, T1623, to create a binding motif, that is critical for MAP2 interaction with and stabilization of microtubules, and dendrite growth control. Targeted expression in M1 of GFP-HMW-MAP2 that is pseudo-phosphorylated on T1619, T1622 and T1625 increases dendrite complexity in L2/3 indicating that JNK1 phosphorylation of HMW-MAP2 regulates the dendritic field. Consistent with the morphological changes observed in L2/3 and L5, Jnk1-/- mice exhibit deficits in limb placement and motor coordination, while stride length is reduced in older animals. In summary, JNK1 phosphorylates HMW-MAP2 to increase its stabilization of microtubules while at the same time controlling dendritic fields in the main excitatory pathway of M1. Moreover, JNK1 contributes to normal functioning of fine motor coordination. We report for the first time, a quantitative sholl analysis of dendrite architecture, and of motor behavior in Jnk1-/- mice. Our results illustrate the molecular and behavioral consequences of interrupted JNK1 signaling and provide new ground for mechanistic understanding of those prevalent neuropyschiatric disorders where genetic disruption of the JNK pathway is central.

  7. Facile synthesis of dendritic Cu by electroless reaction of Cu-Al alloys in multiphase solution

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ying; Liang, Shuhua, E-mail: liangxaut@gmail.com; Yang, Qing; Wang, Xianhui

    2016-11-30

    Highlights: • Nano- or micro-scale fractal dendritic copper (FDC) was synthesized by electroless immersing of Cu-Al alloys in CuCl{sub 2} + HCl. • FDC size increases with the increase of Al content in Cu-Al alloys immersed in CuCl{sub 2} + HCl solution. • Nanoscale Cu{sub 2}O was found at the edge of FDC. Nanoporous copper (NPC) can also be obtained by using Cu{sub 17}Al{sub 83} alloy. • The potential difference between CuAl{sub 2} and α-Al phase and the replacement reaction in multiphase solution are key factors. - Abstract: Two-dimensional nano- or micro-scale fractal dendritic coppers (FDCs) were synthesized by electroless immersing of Cu-Al alloys in hydrochloric acid solution containing copper chloride without any assistance of template or surfactant. The FDC size increases with the increase of Al content in Cu-Al alloys immersed in CuCl{sub 2} + HCl solution. Compared to Cu{sub 40}Al{sub 60} and Cu{sub 45}Al{sub 55} alloys, the FDC shows hierarchical distribution and homogeneous structures using Cu{sub 17}Al{sub 83} alloy as the starting alloy. The growth direction of the FDC is <110>, and all angles between the trunks and branches are 60°. Nanoscale Cu{sub 2}O was found at the edge of FDC. Interestingly, nanoporous copper (NPC) can also be obtained through Cu{sub 17}Al{sub 83} alloy. Studies showed that the formation of FDC depended on two key factors: the potential difference between CuAl{sub 2} intermetallic and α-Al phase of dual-phase Cu-Al alloys; a replacement reaction that usually occurs in multiphase solution. The electrochemical experiment further proved that the multi-branch dendritic structure is very beneficial to the proton transfer in the process of catalyzing methanol.

  8. BAFF and APRIL from Activin A-Treated Dendritic Cells Upregulate the Antitumor Efficacy of Dendritic Cells In Vivo.

    Science.gov (United States)

    Shurin, Michael R; Ma, Yang; Keskinov, Anton A; Zhao, Ruijing; Lokshin, Anna; Agassandian, Marianna; Shurin, Galina V

    2016-09-01

    The members of the TGFβ superfamily play a key role in regulating developmental and homeostasis programs by controlling differentiation, proliferation, polarization, and survival of different cell types. Although the role of TGFβ1 in inflammation and immunity is well evident, the contribution of other TGFβ family cytokines in the modulation of the antitumor immune response remains less documented. Here we show that activin A triggers SMAD2 and ERK1/2 pathways in dendritic cells (DC) expressing type I and II activin receptors, and upregulates production of the TNFα family cytokines BAFF (TALL-1, TNFSF13B) and APRIL (TALL-2, TNFSF13A), which is blocked by SMAD2 and ERK1/2 inhibitors, respectively. BAFF and APRIL derived from activin A-treated DCs upregulate proliferation and survival of T cells expressing the corresponding receptors, BAFF-R and TACI. In vivo, activin A-stimulated DCs demonstrate a significantly increased ability to induce tumor-specific CTLs and inhibit the growth of melanoma and lung carcinoma, which relies on DC-derived BAFF and APRIL, as knockdown of the BAFF and APRIL gene expression in activin A-treated DCs blocks augmentation of their antitumor potential. Although systemic administration of activin A, BAFF, or APRIL for the therapeutic purposes is not likely due to the pluripotent effects on malignant and nonmalignant cells, our data open a novel opportunity for improving the efficacy of DC vaccines. In fact, a significant augmentation of the antitumor activity of DC pretreated with activin A and the proven role of DC-derived BAFF and APRIL in the induction of antitumor immunity in vivo support this direction. Cancer Res; 76(17); 4959-69. ©2016 AACR. ©2016 American Association for Cancer Research.

  9. Human intestinal dendritic cells as controllers of mucosal immunity

    Directory of Open Access Journals (Sweden)

    David Bernardo

    2013-06-01

    Full Text Available Dendritic cells are the most potent, professional antigen-presenting cells in the body; following antigen presentation they control the type (proinflammatory/regulatory of immune response that will take place, as well as its location. Given their high plasticity and maturation ability in response to local danger signals derived from innate immunity, dendritic cells are key actors in the connection between innate immunity and adaptive immunity responses. In the gut dendritic cells control immune tolerance mechanisms against food and/or commensal flora antigens, and are also capable of initiating an active immune response in the presence of invading pathogens. Dendritic cells are thus highly efficient in controlling the delicate balance between tolerance and immunity in an environment so rich in antigens as the gut, and any factor involving these cells may impact their function, ultimately leading to the development of bowel conditions such as celiac disease or inflammatory bowel disease. In this review we shall summarize our understanding of human intestinal dendritic cells, their ability to express and induce migration markers, the various environmental factors modulating their properties, their subsets in the gut, and the problems entailed by their study, including identification strategies, differences between humans and murine models, and phenotypical variations along the gastrointestinal tract.

  10. Systems immunology allows a new view on human dendritic cells.

    Science.gov (United States)

    Schultze, Joachim L; Aschenbrenner, Anna C

    2018-02-24

    As the most important antigen-presenting cells, dendritic cells connect the innate and adaptive part of our immune system and play a pivotal role in our course of action against invading pathogens as well as during successful vaccination. Immunologists have therefore studied these cells in great detail using flow cytometry-based analyses, in vitro assays and in vivo models, both in murine models and in humans. Albeit, sophisticated, classical immunological, and molecular approaches were often unable to unequivocally determine the subpopulation structure of the dendritic cell lineage and not surprisingly, conflicting results about dendritic cell subsets co-existed throughout the last decades. With the advent of systems approaches and the most recent introduction of -omics approaches on the single cell level combined with multi-colour flow cytometry or mass cytometry, we now enter an era allowing us to define cell population structures with an unprecedented precision. We will report here on the most recent studies applying these technologies to human dendritic cells. Proper delineation of and definition of molecular signatures for the different human dendritic cell subsets will greatly facilitate studying these cells in the future: understanding their function under physiological as well as pathological conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. The dendritic cell niche in chronic obstructive pulmonary disease

    Directory of Open Access Journals (Sweden)

    Haczku Angela

    2012-09-01

    Full Text Available Abstract The pulmonary innate immune system is heavily implicated in the perpetual airway inflammation and impaired host defense characterizing Chronic Obstructive Pulmonary Disease (COPD. The airways of patients suffering from COPD are infiltrated by various immune and inflammatory cells including macrophages, neutrophils, T lymphocytes, and dendritic cells. While the role of macrophages, neutrophils and T lymphocytes is well characterized, the contribution of dendritic cells to COPD pathogenesis is still the subject of emerging research. A paper by Botelho and colleagues in the current issue of Respiratory Research investigates the importance of dendritic cell recruitment in cigarette-smoke induced acute and chronic inflammation in mice. Dendritic cells of the healthy lung parenchyma and airways perform an important sentinel function and regulate immune homeostasis. During inflammatory responses the function and migration pattern of these cells is dramatically altered but the underlying mechanisms are incompletely understood. Botelho and colleagues demonstrate here the importance of IL-1R1/IL-1α related mechanisms including CCL20 production in cigarette-smoke induced recruitment of dendritic cells and T cell activation in the mouse lung.

  12. Noise tolerant dendritic lattice associative memories

    Science.gov (United States)

    Ritter, Gerhard X.; Schmalz, Mark S.; Hayden, Eric; Tucker, Marc

    2011-09-01

    Linear classifiers based on computation over the real numbers R (e.g., with operations of addition and multiplication) denoted by (R, +, x), have been represented extensively in the literature of pattern recognition. However, a different approach to pattern classification involves the use of addition, maximum, and minimum operations over the reals in the algebra (R, +, maximum, minimum) These pattern classifiers, based on lattice algebra, have been shown to exhibit superior information storage capacity, fast training and short convergence times, high pattern classification accuracy, and low computational cost. Such attributes are not always found, for example, in classical neural nets based on the linear inner product. In a special type of lattice associative memory (LAM), called a dendritic LAM or DLAM, it is possible to achieve noise-tolerant pattern classification by varying the design of noise or error acceptance bounds. This paper presents theory and algorithmic approaches for the computation of noise-tolerant lattice associative memories (LAMs) under a variety of input constraints. Of particular interest are the classification of nonergodic data in noise regimes with time-varying statistics. DLAMs, which are a specialization of LAMs derived from concepts of biological neural networks, have successfully been applied to pattern classification from hyperspectral remote sensing data, as well as spatial object recognition from digital imagery. The authors' recent research in the development of DLAMs is overviewed, with experimental results that show utility for a wide variety of pattern classification applications. Performance results are presented in terms of measured computational cost, noise tolerance, classification accuracy, and throughput for a variety of input data and noise levels.

  13. Familial Resemblance in Dietary Intakes of Children, Adolescents, and Parents: Does Dietary Quality Play a Role?

    Science.gov (United States)

    Bogl, Leonie H; Silventoinen, Karri; Hebestreit, Antje; Intemann, Timm; Williams, Garrath; Michels, Nathalie; Molnár, Dénes; Page, Angie S; Pala, Valeria; Papoutsou, Stalo; Pigeot, Iris; Reisch, Lucia A; Russo, Paola; Veidebaum, Toomas; Moreno, Luis A; Lissner, Lauren; Kaprio, Jaakko

    2017-08-17

    Information on familial resemblance is important for the design of effective family-based interventions. We aimed to quantify familial correlations and estimate the proportion of variation attributable to genetic and shared environmental effects (i.e., familiality) for dietary intake variables and determine whether they vary by generation, sex, dietary quality, or by the age of the children. The study sample consisted of 1435 families (1007 mothers, 438 fathers, 1035 daughters, and 1080 sons) from the multi-center I.Family study. Dietary intake was assessed in parents and their 2-19 years old children using repeated 24-h dietary recalls, from which the usual energy and food intakes were estimated with the U.S. National Cancer Institute Method. Food items were categorized as healthy or unhealthy based on their sugar, fat, and fiber content. Interclass and intraclass correlations were calculated for relative pairs. Familiality was estimated using variance component methods. Parent-offspring ( r = 0.11-0.33), sibling ( r = 0.21-0.43), and spouse ( r = 0.15-0.33) correlations were modest. Parent-offspring correlations were stronger for the intake of healthy ( r = 0.33) than unhealthy ( r = 0.10) foods. Familiality estimates were 61% (95% CI: 54-68%) for the intake of fruit and vegetables and the sum of healthy foods and only 30% (95% CI: 23-38%) for the sum of unhealthy foods. Familial factors explained a larger proportion of the variance in healthy food intake (71%; 95% CI: 62-81%) in younger children below the age of 11 than in older children equal or above the age of 11 (48%; 95% CI: 38-58%). Factors shared by family members such as genetics and/or the shared home environment play a stronger role in shaping children's intake of healthy foods than unhealthy foods. This suggests that family-based interventions are likely to have greater effects when targeting healthy food choices and families with younger children, and that other sorts of intervention are needed to

  14. NALCN ion channels have alternative selectivity filters resembling calcium channels or sodium channels.

    Directory of Open Access Journals (Sweden)

    Adriano Senatore

    Full Text Available NALCN is a member of the family of ion channels with four homologous, repeat domains that include voltage-gated calcium and sodium channels. NALCN is a highly conserved gene from simple, extant multicellular organisms without nervous systems such as sponges and placozoans and mostly remains a single gene compared to the calcium and sodium channels which diversified into twenty genes in humans. The single NALCN gene has alternatively-spliced exons at exons 15 or exon 31 that splices in novel selectivity filter residues that resemble calcium channels (EEEE or sodium channels (EKEE or EEKE. NALCN channels with alternative calcium, (EEEE and sodium, (EKEE or EEKE -selective pores are conserved in simple bilaterally symmetrical animals like flatworms to non-chordate deuterostomes. The single NALCN gene is limited as a sodium channel with a lysine (K-containing pore in vertebrates, but originally NALCN was a calcium-like channel, and evolved to operate as both a calcium channel and sodium channel for different roles in many invertebrates. Expression patterns of NALCN-EKEE in pond snail, Lymnaea stagnalis suggest roles for NALCN in secretion, with an abundant expression in brain, and an up-regulation in secretory organs of sexually-mature adults such as albumen gland and prostate. NALCN-EEEE is equally abundant as NALCN-EKEE in snails, but is greater expressed in heart and other muscle tissue, and 50% less expressed in the brain than NALCN-EKEE. Transfected snail NALCN-EEEE and NALCN-EKEE channel isoforms express in HEK-293T cells. We were not able to distinguish potential NALCN currents from background, non-selective leak conductances in HEK293T cells. Native leak currents without expressing NALCN genes in HEK-293T cells are NMDG(+ impermeant and blockable with 10 µM Gd(3+ ions and are indistinguishable from the hallmark currents ascribed to mammalian NALCN currents expressed in vitro by Lu et al. in Cell. 2007 Apr 20;129(2:371-83.

  15. Imaging manifestations of acquired elastopathy resembling pseudoxanthoma elasticum in patients with beta thalassaemia major and sickle cell disease

    International Nuclear Information System (INIS)

    Narayana, Harish; Cheng, Ken; Lau, Ken; Harish, Radhika; Bowden, Donald K.

    2016-01-01

    Development of an acquired systemic elastopathy resembling pseudoxanthoma elasticum in patients with chronic haemoglobinopathies such as beta thalassaemia major and sickle cell disease is well documented. There is paucity of any comprehensive literature on the radiological manifestations of this entity. This pictorial review aims to describe and illustrate the multi system and multi modality imaging findings of this condition.

  16. What's in a child's face? : effects of facial resemblance, love withdrawal, empathy and context on behavioral and neural responses

    NARCIS (Netherlands)

    Heckendorf, E.

    2018-01-01

    The aim of this thesis is to increase our knowledge of individual differences in the neural processing and appraisal of children’s faces that differ in their degree of resemblance with the participant’s face. Chapter 2 focuses on participants’ neural responses to child faces that differ in

  17. CD163 positive subsets of blood dendritic cells

    DEFF Research Database (Denmark)

    Maniecki, Maciej Bogdan; Møller, Holger Jon; Moestrup, Søren Kragh

    2006-01-01

    expression in dendritic cells (DCs) was investigated using multicolor flow cytometry in peripheral blood from 31 healthy donors and 15 HIV-1 patients in addition to umbilical cord blood from 5 newborn infants. Total RNA was isolated from MACS purified DCs and CD163 mRNA was determined with real-time reverse...... transcriptase polymerase chain reaction. The effect of glucocorticoid and phorbol ester stimulation on monocyte and dendritic cell CD163 and CD91 expression was investigated in cell culture of mononuclear cells using multicolor flow cytometry. We identified two CD163+ subsets in human blood with dendritic cell...... characteristics, CD163lo and CD163hi, together constituting a substantial fraction of DCs. Both subsets were characterized as [lin]- CD4+ ILT3+ HLA-DR+ CD11c+ by flow cytometry, and CD163 mRNA was readily detectable in MACS purified human DCs. CD163 on DCs was upregulated by glucocorticoid, and treatment...

  18. Immunity and Tolerance Induced by Intestinal Mucosal Dendritic Cells

    Directory of Open Access Journals (Sweden)

    Julio Aliberti

    2016-01-01

    Full Text Available Dendritic cells present in the digestive tract are constantly exposed to environmental antigens, commensal flora, and invading pathogens. Under steady-state conditions, these cells have high tolerogenic potential, triggering differentiation of regulatory T cells to protect the host from unwanted proinflammatory immune responses to innocuous antigens or commensals. On the other hand, these cells must discriminate between commensal flora and invading pathogens and mount powerful immune response against pathogens. A potential result of unbalanced tolerogenic versus proinflammatory responses mediated by dendritic cells is associated with chronic inflammatory conditions, such as Crohn’s disease, ulcerative colitis, food allergies, and celiac disease. Herein, we review the dendritic cell population involved in mediating tolerance and immunity in mucosal surfaces, the progress in unveiling their development in vivo, and factors that can influence their functions.

  19. Electrical behaviour of dendritic spines as revealed by voltage imaging.

    Science.gov (United States)

    Popovic, Marko A; Carnevale, Nicholas; Rozsa, Balazs; Zecevic, Dejan

    2015-10-05

    Thousands of dendritic spines on individual neurons process information and mediate plasticity by generating electrical input signals using a sophisticated assembly of transmitter receptors and voltage-sensitive ion channel molecules. Our understanding, however, of the electrical behaviour of spines is limited because it has not been possible to record input signals from these structures with adequate sensitivity and spatiotemporal resolution. Current interpretation of indirect data and speculations based on theoretical considerations are inconclusive. Here we use an electrochromic voltage-sensitive dye which acts as a transmembrane optical voltmeter with a linear scale to directly monitor electrical signals from individual spines on thin basal dendrites. The results show that synapses on these spines are not electrically isolated by the spine neck to a significant extent. Electrically, they behave as if they are located directly on dendrites.

  20. Complete response of metastatic renal cancer with dendritic cell vaccine

    Directory of Open Access Journals (Sweden)

    Dall'Oglio Marcos

    2003-01-01

    Full Text Available INTRODUCTION: We report a case of metastatic renal cell carcinoma that presented involution following therapy with dendritic cells. CASE REPORT: Male, 51-year old patient underwent left radical nephrectomy in September 1999 due to renal cell carcinoma, evolved with recurrence of the neoplasia in January 2002, confirmed by resection of the lesion. A vaccine therapy based on dendritic cells was then performed during 5 months (4 applications. After this period, there was occurrence of new lesions, whose resection revealed areas of necrosis and inflammatory infiltrate. DISCUSSION: The outcome of renal cell carcinoma is influenced by prognostic factors that confer more aggressive tumor characteristics. However, in cases of recurrence, the systemic therapy with dendritic cells-based vaccine can be associated with a better outcome with regression of disease.

  1. The ?conscious pilot??dendritic synchrony moves through the brain to mediate consciousness

    OpenAIRE

    Hameroff, Stuart

    2009-01-01

    Cognitive brain functions including sensory processing and control of behavior are understood as ?neurocomputation? in axonal?dendritic synaptic networks of ?integrate-and-fire? neurons. Cognitive neurocomputation with consciousness is accompanied by 30- to 90-Hz gamma synchrony electroencephalography (EEG), and non-conscious neurocomputation is not. Gamma synchrony EEG derives largely from neuronal groups linked by dendritic?dendritic gap junctions, forming transient syncytia (?dendritic web...

  2. A Novel Forward Genetic Screen for Identifying Mutations Affecting Larval Neuronal Dendrite Development in Drosophila melanogaster

    OpenAIRE

    Medina, Paul Mark B.; Swick, Lance L.; Andersen, Ryan; Blalock, Zachary; Brenman, Jay E.

    2006-01-01

    Vertebrate and invertebrate dendrites are information-processing compartments that can be found on both central and peripheral neurons. Elucidating the molecular underpinnings of information processing in the nervous system ultimately requires an understanding of the genetic pathways that regulate dendrite formation and maintenance. Despite the importance of dendrite development, few forward genetic approaches have been used to analyze the latest stages of dendrite development, including the ...

  3. Age and Gender Differences in Facial Attractiveness, but Not Emotion Resemblance, Contribute to Age and Gender Stereotypes

    Directory of Open Access Journals (Sweden)

    Rocco Palumbo

    2017-09-01

    Full Text Available Considerable research has shown effects of facial appearance on trait impressions and group stereotypes. We extended those findings in two studies that investigated the contribution of resemblance to emotion expressions and attractiveness to younger adults (YA and older adults (OA age and gender stereotypes on the dimensions of warmth and competence. Using connectionist modeling of facial metrics of 240 neutral younger and older faces, Study 1 found that, neutral expression older faces or female faces showed greater structural resemblance to happy expressions and less resemblance to angry expressions than did younger or male faces, respectively. In addition, neutral female faces showed greater resemblance to surprise expressions. In Study 2, YA and OA rated the faces of Study 1 for attractiveness and for 4 traits that we aggregated on the dimensions of competence (competent, healthy and warmth (trustworthy, not shrewd. We found that YA, but not OA, age stereotypes replicated previous research showing higher perceived warmth and lower perceived competence in older adults. In addition, previously documented gender stereotypes were moderated by face age for both YA and OA. The greater attractiveness of younger than older faces and female than male faces influenced age and gender stereotypes, including these deviations from prior research findings using category labels rather than faces. On the other hand, face age and face sex differences in emotion resemblance did not influence age or gender stereotypes, contrary to prediction. Our results provide a caveat to conclusions about age and gender stereotypes derived from responses to category labels, and they reveal the importance of assessing stereotypes with a methodology that is sensitive to influences of group differences in appearance that can exacerbate or mitigate stereotypes in more ecologically valid contexts. Although the gender differences in attractiveness in the present study may not have

  4. Age and Gender Differences in Facial Attractiveness, but Not Emotion Resemblance, Contribute to Age and Gender Stereotypes.

    Science.gov (United States)

    Palumbo, Rocco; Adams, Reginald B; Hess, Ursula; Kleck, Robert E; Zebrowitz, Leslie

    2017-01-01

    Considerable research has shown effects of facial appearance on trait impressions and group stereotypes. We extended those findings in two studies that investigated the contribution of resemblance to emotion expressions and attractiveness to younger adults (YA) and older adults (OA) age and gender stereotypes on the dimensions of warmth and competence. Using connectionist modeling of facial metrics of 240 neutral younger and older faces, Study 1 found that, neutral expression older faces or female faces showed greater structural resemblance to happy expressions and less resemblance to angry expressions than did younger or male faces, respectively. In addition, neutral female faces showed greater resemblance to surprise expressions. In Study 2, YA and OA rated the faces of Study 1 for attractiveness and for 4 traits that we aggregated on the dimensions of competence (competent, healthy) and warmth (trustworthy, not shrewd). We found that YA, but not OA, age stereotypes replicated previous research showing higher perceived warmth and lower perceived competence in older adults. In addition, previously documented gender stereotypes were moderated by face age for both YA and OA. The greater attractiveness of younger than older faces and female than male faces influenced age and gender stereotypes, including these deviations from prior research findings using category labels rather than faces. On the other hand, face age and face sex differences in emotion resemblance did not influence age or gender stereotypes, contrary to prediction. Our results provide a caveat to conclusions about age and gender stereotypes derived from responses to category labels, and they reveal the importance of assessing stereotypes with a methodology that is sensitive to influences of group differences in appearance that can exacerbate or mitigate stereotypes in more ecologically valid contexts. Although the gender differences in attractiveness in the present study may not have generalizability

  5. Primary Dendrite Arm Spacing and Trunk Diameter in Al-7-Weight-Percentage Si Alloy Directionally Solidified Aboard the International Space Station

    Science.gov (United States)

    Ghods, M.; Tewari, S. N.; Lauer, M.; Poirier, D. R.; Grugel, R. N.

    2016-01-01

    Under a NASA-ESA collaborative research project, three Al-7-weight-percentage Si samples (MICAST-6, MICAST-7 and MICAST 2-12) were directionally solidified aboard the International Space Station to determine the effect of mitigating convection on the primary dendrite array. The samples were approximately 25 centimeters in length with a diameter of 7.8 millimeter-diameter cylinders that were machined from [100] oriented terrestrially grown dendritic Al-7Si samples and inserted into alumina ampoules within the Sample Cartridge Assembly (SCA) inserts of the Low Gradient Furnace (LGF). The feed rods were partially remelted in space and directionally solidified to effect the [100] dendrite-orientation. MICAST-6 was grown at 5 microns per second for 3.75 centimeters and then at 50 microns per second for its remaining 11.2 centimeters of its length. MICAST-7 was grown at 20 microns per second for 8.5 centimeters and then at 10 microns per second for 9 centimeters of its remaining length. MICAST2-12 was grown at 40 microns per second for 11 centimeters. The thermal gradient at the liquidus temperature varied from 22 to 14 degrees Kelvin per centimeter during growth of MICAST-6, from 26 to 24 degrees Kelvin per centimeter for MICAST-7 and from 33 to 31 degrees Kelvin per centimeter for MICAST2-12. Microstructures on the transverse sections along the sample length were analyzed to determine nearest-neighbor spacing of the primary dendrite arms and trunk diameters of the primary dendrite-arrays. This was done along the lengths where steady-state growth prevailed and also during the transients associated with the speed-changes. The observed nearest-neighbor spacings during steady-state growth of the MICAST samples show a very good agreement with predictions from the Hunt-Lu primary spacing model for diffusion controlled growth. The observed primary dendrite trunk diameters during steady-state growth of these samples also agree with predictions from a coarsening-based model

  6. Blastic plasmacytoid dendritic cell neoplasm with absolute monocytosis at presentation

    Directory of Open Access Journals (Sweden)

    Jaworski JM

    2015-02-01

    Full Text Available Joseph M Jaworski,1,2 Vanlila K Swami,1 Rebecca C Heintzelman,1 Carrie A Cusack,3 Christina L Chung,3 Jeremy Peck,3 Matthew Fanelli,3 Micheal Styler,4 Sanaa Rizk,4 J Steve Hou1 1Department of Pathology and Laboratory Medicine, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA; 2Department of Pathology, Mercy Fitzgerald Hospital, Darby, PA, USA; 3Department of Dermatology, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA; 4Department of Hematology/Oncology, Hahnemann University Hospital/Drexel University College of Medicine, Philadelphia, PA, USA Abstract: Blastic plasmacytoid dendritic cell neoplasm is an uncommon malignancy derived from precursors of plasmacytoid dendritic cells. Nearly all patients present initially with cutaneous manifestations, with many having extracutaneous disease additionally. While response to chemotherapy initially is effective, relapse occurs in most, with a leukemic phase ultimately developing. The prognosis is dismal. While most of the clinical and pathologic features are well described, the association and possible prognostic significance between peripheral blood absolute monocytosis (>1.0 K/µL and blastic plasmacytoid dendritic cell neoplasm have not been reported. We report a case of a 68-year-old man who presented with a rash for 4–5 months. On physical examination, there were multiple, dull-pink, indurated plaques on the trunk and extremities. Complete blood count revealed thrombocytopenia, absolute monocytosis of 1.7 K/µL, and a negative flow cytometry study. Biopsy of an abdominal lesion revealed typical features of blastic plasmacytoid dendritic cell neoplasm. Patients having both hematologic and nonhematologic malignancies have an increased incidence of absolute monocytosis. Recent studies examining Hodgkin and non-Hodgkin lymphoma patients have suggested that this is a negative prognostic factor. The association between

  7. Differential intensity-dependent effects of magnetic stimulation on the longest neurites and shorter dendrites in neuroscreen-1 cells

    Science.gov (United States)

    Lin, Ching-Yi; Huang, Whitney J.; Li, Kevin; Swanson, Roy; Cheung, Brian; Lin, Vernon W.; Lee, Yu-Shang

    2015-04-01

    Objective. Magnetic stimulation (MS) is a potential treatment for neuropsychiatric disorders. This study investigates whether MS-regulated neuronal activity can translate to specific changes in neuronal arborization and thus regulate synaptic activity and function. Approach. To test our hypotheses, we examined the effects of MS on neurite growth of neuroscreen-1 (NS-1) cells over the pulse frequencies of 1, 5 and 10 Hz at field intensities controlled via machine output (MO). Cells were treated with either 30% or 40% MO. Due to the nature of circular MS coils, the center region of the gridded coverslip (zone 1) received minimal (∼5%) electromagnetic current density while the remaining area (zone 2) received maximal (∼95%) current density. Plated NS-1 cells were exposed to MS twice per day for three days and then evaluated for length and number of neurites and expression of brain-derived neurotrophic factor (BDNF). Main results. We show that MS dramatically affects the growth of the longest neurites (axon-like) but does not significantly affect the growth of shorter neurites (dendrite-like). Also, MS-induced changes in the longest neurite growth were most evident in zone 1, but not in zone 2. MS effects were intensity-dependent and were most evident in bolstering longest neurite outgrowth, best seen in the 10 Hz MS group. Furthermore, we found that MS-increased BDNF expression and secretion was also frequency-dependent. Taken together, our results show that MS exerts distinct effects when different frequencies and intensities are applied to the neuritic compartments (longest neurite versus shorter dendrite(s)) of NS-1 cells. Significance. These findings support the concept that MS increases BDNF expression and signaling, which sculpts longest neurite arborization and connectivity by which neuronal activity is regulated. Understanding the mechanisms underlying MS is crucial for efficiently incorporating its use into potential therapeutic strategies.

  8. Modelling dendritic ecological networks in space: anintegrated network perspective

    Science.gov (United States)

    Peterson, Erin E.; Ver Hoef, Jay M.; Isaak, Dan J.; Falke, Jeffrey A.; Fortin, Marie-Josée; Jordon, Chris E.; McNyset, Kristina; Monestiez, Pascal; Ruesch, Aaron S.; Sengupta, Aritra; Som, Nicholas; Steel, E. Ashley; Theobald, David M.; Torgersen, Christian E.; Wenger, Seth J.

    2013-01-01

    Dendritic ecological networks (DENs) are a unique form of ecological networks that exhibit a dendritic network topology (e.g. stream and cave networks or plant architecture). DENs have a dual spatial representation; as points within the network and as points in geographical space. Consequently, some analytical methods used to quantify relationships in other types of ecological networks, or in 2-D space, may be inadequate for studying the influence of structure and connectivity on ecological processes within DENs. We propose a conceptual taxonomy of network analysis methods that account for DEN characteristics to varying degrees and provide a synthesis of the different approaches within

  9. Clinical application of dendritic cells in cancer vaccination therapy

    DEFF Research Database (Denmark)

    Svane, Inge Marie; Soot, Mette Line; Buus, Søren

    2003-01-01

    During the last decade use of dendritic cells (DC) has moved from murine and in vitro studies to clinical trials as adjuvant in cancer immunotherapy. Here they function as delivery vehicles for exogenous tumor antigens, promoting an efficient antigen presentation. The development of protocols...... for large-scale generation of dendritic cells for clinical applications has made possible phase I/II studies designed to analyze the toxicity, feasibility and efficacy of this approach. In clinical trials, DC-based vaccination of patients with advanced cancer has in many cases led to immunity...

  10. Butyrate and retinoic acid imprint mucosal-like dendritic cell development synergistically from bone marrow cells.

    Science.gov (United States)

    Qiang, Y; Xu, J; Yan, C; Jin, H; Xiao, T; Yan, N; Zhou, L; An, H; Zhou, X; Shao, Q; Xia, S

    2017-09-01

    Accumulating data show that the phenotypes and functions of distinctive mucosal dendritic cells (DCs) in the gut are regulated by retinoic acid (RA). Unfortunately, the exact role of butyrate in RA-mediated mucosal DC differentiation has not been elucidated thoroughly to date. Mucosal-like dendritic cell differentiation was completed in vitro by culturing bone marrow cells with growth factors [granulocyte-macrophage colony-stimulating factor (GM-CSF/interleukin (IL)-4], RA and/or butyrate. The phenotypes, cytokine secretion, immune functions and levels of retinal dehydrogenase of different DCs were detected using quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA) and flow cytometry, respectively. The results showed that RA-induced DCs (RA-DCs) showed mucosal DC properties, including expression of CD103 and gut homing receptor α 4 β 7 , low proinflammatory cytokine secretion and low priming capability to antigen-specific CD4 + T cells. Butyrate-treated RA-DCs (Bu-RA-DCs) decreased CD11c, but increased CD103 and α 4 β 7 expression. Moreover, the CD4 + T priming capability and the levels of retinal dehydrogenase of RA-DCs were suppressed significantly by butyrate. Thus, butyrate and retinoic acid have different but synergistic regulatory functions on mucosal DC differentiation, indicating that immune homeostasis in the gut depends largely upon RA and butyrate to imprint different mucosal DC subsets, both individually and collectively. © 2017 British Society for Immunology.

  11. Facile synthesis of dendritic Cu by electroless reaction of Cu-Al alloys in multiphase solution

    Science.gov (United States)

    Wang, Ying; Liang, Shuhua; Yang, Qing; Wang, Xianhui

    2016-11-01

    Two-dimensional nano- or micro-scale fractal dendritic coppers (FDCs) were synthesized by electroless immersing of Cu-Al alloys in hydrochloric acid solution containing copper chloride without any assistance of template or surfactant. The FDC size increases with the increase of Al content in Cu-Al alloys immersed in CuCl2 + HCl solution. Compared to Cu40Al60 and Cu45Al55 alloys, the FDC shows hierarchical distribution and homogeneous structures using Cu17Al83 alloy as the starting alloy. The growth direction of the FDC is , and all angles between the trunks and branches are 60°. Nanoscale Cu2O was found at the edge of FDC. Interestingly, nanoporous copper (NPC) can also be obtained through Cu17Al83 alloy. Studies showed that the formation of FDC depended on two key factors: the potential difference between CuAl2 intermetallic and α-Al phase of dual-phase Cu-Al alloys; a replacement reaction that usually occurs in multiphase solution. The electrochemical experiment further proved that the multi-branch dendritic structure is very beneficial to the proton transfer in the process of catalyzing methanol.

  12. File list: InP.Bld.05.AllAg.Dendritic_Cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Bld.05.AllAg.Dendritic_Cells mm9 Input control Blood Dendritic Cells SRX885956,...76,SRX122481,SRX667880,SRX667874,SRX667878 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/assembled/InP.Bld.05.AllAg.Dendritic_Cells.bed ...

  13. File list: Unc.Bld.50.AllAg.Dendritic_Cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Bld.50.AllAg.Dendritic_Cells hg19 Unclassified Blood Dendritic Cells SRX818200,...203,SRX818202,SRX818182,SRX818195,SRX818196,SRX818181 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.Bld.50.AllAg.Dendritic_Cells.bed ...

  14. File list: InP.Bld.10.AllAg.Dendritic_Cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available InP.Bld.10.AllAg.Dendritic_Cells hg19 Input control Blood Dendritic Cells SRX627429...,SRX627427 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/InP.Bld.10.AllAg.Dendritic_Cells.bed ...

  15. File list: Unc.Bld.20.AllAg.Dendritic_Cells [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Unc.Bld.20.AllAg.Dendritic_Cells hg19 Unclassified Blood Dendritic Cells SRX818200,...189,SRX818202,SRX818182,SRX818195,SRX818196,SRX818181 http://dbarchive.biosciencedbc.jp/kyushu-u/hg19/assembled/Unc.Bld.20.AllAg.Dendritic_Cells.bed ...

  16. Dendrite-free Li metal anode enabled by a 3D free-standing lithiophilic nitrogen-enriched carbon sponge

    Science.gov (United States)

    Hou, Guangmei; Ren, Xiaohua; Ma, Xiaoxin; Zhang, Le; Zhai, Wei; Ai, Qing; Xu, Xiaoyan; Zhang, Lin; Si, Pengchao; Feng, Jinkui; Ding, Fei; Ci, Lijie

    2018-05-01

    Lithium metal is considered as the ultimate anode material for high-energy Li battery systems. However, the commercial application of lithium anode is impeded by issues with safety and low coulombic efficiency induced by Li dendrite growth. Herein, a free-standing three-dimensional nitrogen-enriched graphitic carbon sponge with a high nitrogen content is proposed as a multifunctional current collect for Lithium accommodation. The abundant lithiophilic N-containing functional groups are served as preferred nucleation sites to guide a uniform Li deposition. In addition, the nitrogen-enriched graphitic carbon sponge with a high specific surface area can effectively reduce the local current density. As a result of the synergistic effect, the nitrogen-enriched graphitic carbon sponge electrode realizes a long-term stable cycling without dendrites formation. Notably, the as-obtained composite electrode can deliver an ultra-high specific capacity of ∼3175 mA h g-1. The nitrogen-enriched graphitic carbon sponge might provide innovative insights to design a superior matrix for dendrite-free Li anode.

  17. Phenotypes of non-attached Pseudomonas aeruginosa aggregates resemble surface attached biofilm.

    Directory of Open Access Journals (Sweden)

    Morten Alhede

    Full Text Available For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse conditions. However, microscopic investigations of samples isolated from sites of chronic infections seem to suggest that some bacteria do not need to be attached to surfaces in order to establish chronic infections. In this study we employed scanning electron microscopy, confocal laser scanning microscopy, RT-PCR as well as traditional culturing techniques to study the properties of Pseudomonas aeruginosa aggregates. We found that non-attached aggregates from stationary-phase cultures have comparable growth rates to surface attached biofilms. The growth rate estimations indicated that, independently of age, both aggregates and flow-cell biofilm had the same slow growth rate as a stationary phase shaking cultures. Internal structures of the aggregates matrix components and their capacity to survive otherwise lethal treatments with antibiotics (referred to as tolerance and resistance to phagocytes were also found to be strikingly similar to flow-cell biofilms. Our data indicate that the tolerance of both biofilms and non-attached aggregates towards antibiotics is reversible by physical disruption. We provide evidence that the antibiotic tolerance is likely to be dependent on both the physiological states of the aggregates and particular matrix components. Bacterial surface-attachment and subsequent biofilm formation are considered hallmarks of the capacity of microbes to cause persistent infections. We have observed non-attached aggregates in the lungs of cystic fibrosis patients; otitis media; soft tissue fillers and non-healing wounds, and we propose that aggregated cells exhibit enhanced survival in the hostile host environment, compared with non

  18. Dendritic orientation and branching distinguish a class of multifunctional turtle spinal interneurons

    Directory of Open Access Journals (Sweden)

    Jonathan R. Holmes

    2014-11-01

    Full Text Available Spinal interneurons can integrate diverse propriospinal and supraspinal inputs that trigger or modulate locomotion and other limb movements. These synaptic inputs can occur on distal dendrites and yet must remain effective at the soma. Active dendritic conductances may amplify distal dendritic inputs, but appear to play a minimal role during scratching, at least. Another possibility is that spinal interneurons that integrate inputs on distal dendrites have unusually simple dendritic trees that effectively funnel current to the soma. We previously described a class of spinal interneurons, called transverse interneurons (or T neurons, in adult turtles. T neurons were defined as having dendrites that extend further in the transverse plane than rostrocaudally and a soma that extends further mediolaterally than rostrocaudally. T neurons are multifunctional, as they were activated during both swimming and scratching motor patterns. T neurons had higher peak firing rates and larger membrane potential oscillations during scratching than scratch-activated interneurons with different dendritic morphologies (non-T neurons. These characteristics make T neurons good candidates to play an important role in integrating diverse inputs and generating or relaying rhythmic motor patterns.Here, we quantitatively investigated additional dendritic morphological characteristics of T neurons as compared to non-T neurons. We found that T neurons have less total dendritic length, a greater proportion of dendritic length in primary dendrites, and dendrites that are oriented more mediolaterally. Thus, T neuron dendritic trees extend far mediolaterally, yet are unusually simple, which may help channel synaptic current from distal dendrites in the lateral and ventral funiculi to the soma. In combination with T neuron physiological properties, these dendritic properties may help integrate supraspinal and propriospinal inputs and generate and/or modulate rhythmic limb

  19. Difference in trafficking of brain-derived neurotrophic factor between axons and dendrites of cortical neurons, revealed by live-cell imaging

    Directory of Open Access Journals (Sweden)

    Kohara Keigo

    2005-06-01

    Full Text Available Abstract Background Brain-derived neurotrophic factor (BDNF, which is sorted into a regulated secretory pathway of neurons, is supposed to act retrogradely through dendrites on presynaptic neurons or anterogradely through axons on postsynaptic neurons. Depending on which is the case, the pattern and direction of trafficking of BDNF in dendrites and axons are expected to be different. To address this issue, we analyzed movements of green fluorescent protein (GFP-tagged BDNF in axons and dendrites of living cortical neurons by time-lapse imaging. In part of the experiments, the expression of BDNF tagged with cyan fluorescent protein (CFP was compared with that of nerve growth factor (NGF tagged with yellow fluorescent protein (YFP, to see whether fluorescent protein-tagged BDNF is expressed in a manner specific to this neurotrophin. Results We found that BDNF tagged with GFP or CFP was expressed in a punctated manner in dendrites and axons in about two-thirds of neurons into which plasmid cDNAs had been injected, while NGF tagged with GFP or YFP was diffusely expressed even in dendrites in about 70% of the plasmid-injected neurons. In neurons in which BDNF-GFP was expressed as vesicular puncta in axons, 59 and 23% of the puncta were moving rapidly in the anterograde and retrograde directions, respectively. On the other hand, 64% of BDNF-GFP puncta in dendrites did not move at all or fluttered back and forth within a short distance. The rest of the puncta in dendrites were moving relatively smoothly in either direction, but their mean velocity of transport, 0.47 ± 0.23 (SD μm/s, was slower than that of the moving puncta in axons (0.73 ± 0.26 μm/s. Conclusion The present results show that the pattern and velocity of the trafficking of fluorescence protein-tagged BDNF are different between axons and dendrites, and suggest that the anterograde transport in axons may be the dominant stream of BDNF to release sites.

  20. Targeting of NF-κB to Dendritic Spines Is Required for Synaptic Signaling and Spine Development.

    Science.gov (United States)

    Dresselhaus, Erica C; Boersma, Matthew C H; Meffert, Mollie K

    2018-04-25

    Long-term forms of brain plasticity share a requirement for changes in gene expression induced by neuronal activity. Mechanisms that determine how the distinct and overlapping functions of multiple activity-responsive transcription factors, including nuclear factor κB (NF-κB), give rise to stimulus-appropriate neuronal responses remain unclear. We report that the p65/RelA subunit of NF-κB confers subcellular enrichment at neuronal dendritic spines and engineer a p65 mutant that lacks spine enrichment (p65ΔSE) but retains inherent transcriptional activity equivalent to wild-type p65. Wild-type p65 or p65ΔSE both rescue NF-κB-dependent gene expression in p65-deficient murine hippocampal neurons responding to diffuse (PMA/ionomycin) stimulation. In contrast, neurons lacking spine-enriched NF-κB are selectively impaired in NF-κB-dependent gene expression induced by elevated excitatory synaptic stimulation (bicuculline or glycine). We used the setting of excitatory synaptic activity during development that produces NF-κB-dependent growth of dendritic spines to test physiological function of spine-enriched NF-κB in an activity-dependent response. Expression of wild-type p65, but not p65ΔSE, is capable of rescuing spine density to normal levels in p65-deficient pyramidal neurons. Collectively, these data reveal that spatial localization in dendritic spines contributes unique capacities to the NF-κB transcription factor in synaptic activity-dependent responses. SIGNIFICANCE STATEMENT Extensive research has established a model in which the regulation of neuronal gene expression enables enduring forms of plasticity and learning. However, mechanisms imparting stimulus specificity to gene regulation, ensuring biologically appropriate responses, remain incompletely understood. NF-κB is a potent transcription factor with evolutionarily conserved functions in learning and the growth of excitatory synaptic contacts. Neuronal NF-κB is localized in both synapse and

  1. Excessive astrocyte-derived neurotrophin-3 contributes to the abnormal neuronal dendritic development in a mouse model of fragile X syndrome.

    Directory of Open Access Journals (Sweden)

    Qi Yang

    Full Text Available Fragile X syndrome (FXS is a form of inherited mental retardation in humans that results from expansion of a CGG repeat in the Fmr1 gene. Recent studies suggest a role of astrocytes in neuronal development. However, the mechanisms involved in the regulation process of astrocytes from FXS remain unclear. In this study, we found that astrocytes derived from a Fragile X model, the Fmr1 knockout (KO mouse which lacks FMRP expression, inhibited the proper elaboration of dendritic processes of neurons in vitro. Furthermore, astrocytic conditioned medium (ACM from KO astrocytes inhibited proper dendritic growth of both wild-type (WT and KO neurons. Inducing expression of FMRP by transfection of FMRP vectors in KO astrocytes restored dendritic morphology and levels of synaptic proteins. Further experiments revealed elevated levels of the neurotrophin-3 (NT-3 in KO ACM and the prefrontal cortex of Fmr1 KO mice. However, the levels of nerve growth factor (NGF, brain-derived neurotrophic factor (BDNF, glial cell-derived neurotrophic factor (GDNF, and ciliary neurotrophic factor (CNTF were normal. FMRP has multiple RNA-binding motifs and is involved in translational regulation. RNA-binding protein immunoprecipitation (RIP showed the NT-3 mRNA interacted with FMRP in WT astrocytes. Addition of high concentrations of exogenous NT-3 to culture medium reduced the dendrites of neurons and synaptic protein levels, whereas these measures were ameliorated by neutralizing antibody to NT-3 or knockdown of NT-3 expression in KO astrocytes through short hairpin RNAs (shRNAs. Prefrontal cortex microinjection of WT astrocytes or NT-3 shRNA infected KO astrocytes rescued the deficit of trace fear memory in KO mice, concomitantly decreased the NT-3 levels in the prefrontal cortex. This study indicates that excessive NT-3 from astrocytes contributes to the abnormal neuronal dendritic development and that astrocytes could be a potential therapeutic target for FXS.

  2. Monocyte-derived dendritic cells are essential for CD8+ T cell activation and anti-tumor responses after local immunotherapy

    Directory of Open Access Journals (Sweden)

    Sabine eKuhn

    2015-11-01

    Full Text Available Tumors harbor several populations of dendritic cells with the ability to prime tumor-specific T cells. However, these T cells mostly fail to differentiate into armed effectors and are unable to control tumor growth. We have previously shown that treatment with immunostimulatory agents at the tumor site can activate anti-tumor immune responses, and is associated with the appearance of a population of monocyte-derived dendritic cells in the tumor and tumor-draining lymph node. Here we use dendritic cell or monocyte depletion and monocyte transfer to show that these monocyte-derived dendritic cells are critical to the activation of anti-tumor immune responses. Treatment with the immunostimulatory agents Monosodium Urate crystals and Mycobacterium smegmatis induced the accumulation of monocytes in the draining lymph node, their upregulation of CD11c and MHCII, and expression of iNOS, TNFα and IL12p40. Blocking monocyte entry into the lymph node and tumor through neutralization of the chemokine CCL2 or inhibition of Colony Stimulating Factor-1 receptor signaling prevented the generation of monocyte-derived dendritic cells, the infiltration of tumor-specific T cells into the tumor, and anti-tumor responses. In a reciprocal fashion, monocytes transferred into mice depleted of CD11c+ cells were sufficient to rescue CD8+ T cell priming in lymph node and delay tumor growth. Thus monocytes exposed to the appropriate conditions become powerful activators of tumor-specific CD8+ T cells and anti-tumor immunity.

  3. Genetically modified dendritic cell-based cancer vaccines

    Czech Academy of Sciences Publication Activity Database

    Bubeník, Jan

    2001-01-01

    Roč. 47, č. 5 (2001), s. 153-155 ISSN 0015-5500 R&D Projects: GA MZd NC5526 Keywords : dendritic cells * cancer vaccines Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.519, year: 2001

  4. Dendritic and Axonal Wiring Optimization of Cortical GABAergic Interneurons.

    Science.gov (United States)

    Anton-Sanchez, Laura; Bielza, Concha; Benavides-Piccione, Ruth; DeFelipe, Javier; Larrañaga, Pedro

    2016-10-01

    The way in which a neuronal tree expands plays an important role in its functional and computational characteristics. We aimed to study the existence of an optimal neuronal design for different types of cortical GABAergic neurons. To do this, we hypothesized that both the axonal and dendritic trees of individual neurons optimize brain connectivity in terms of wiring length. We took the branching points of real three-dimensional neuronal reconstructions of the axonal and dendritic trees of different types of cortical interneurons and searched for the minimal wiring arborization structure that respects the branching points. We compared the minimal wiring arborization with real axonal and dendritic trees. We tested this optimization problem using a new approach based on graph theory and evolutionary computation techniques. We concluded that neuronal wiring is near-optimal in most of the tested neurons, although the wiring length of dendritic trees is generally nearer to the optimum. Therefore, wiring economy is related to the way in which neuronal arborizations grow irrespective of the marked differences in the morphology of the examined interneurons.

  5. Processing of MHC class II in dendritic cells

    NARCIS (Netherlands)

    ten Broeke, A.G.

    2012-01-01

    In the past years we performed studies to gain more insight into the processing of major histocompatibility class II (MHC class II) in dendritic cells. We focused on the sorting mechanisms of MHC class II, the degradation of its associated Ii and peptide loading at the endosomal system. In addition,

  6. Utilizing dendritic scaffold for feasible formation of naphthalene ...

    Indian Academy of Sciences (India)

    the effect of dendritic scaffolds on the feasibility of naphthalene excimer formation has not been reported in the literature. Here, we report synthesis and photophysical study of naphthalene functionalized zero and first genera- tion PAMAM dendrimers in order to understand the mechanism of excimer formation in the system.

  7. Circulating dendritic cells in pediatric patients with nephrotic syndrome

    African Journals Online (AJOL)

    Background: Dendritic cells (DCs) represent one of the most extensively studied topics in immunology, because of their central role in the induction and regulation of adaptive immunity, and because of their therapeutic potential for manipulating immune responses. Objectives: To evaluate circulating DC levels in pediatric ...

  8. Virosome-mediated delivery of protein antigens to dendritic cells

    NARCIS (Netherlands)

    Bungener, L; Serre, K; Bijl, L; Leserman, L; Wilschut, J; Daemen, T; Machy, P

    2002-01-01

    Virosomes are reconstituted viral membranes in which protein can be encapsulated. Fusion-active virosomes, fusion-inactive virosomes and liposomes were used to study the conditions needed for delivery of encapsulated protein antigen ovalbumin (OVA) to dendritic cells (DCs) for MHC class I and 11

  9. Modulation of cytokine production profiles in splenic dendritic cells ...

    African Journals Online (AJOL)

    We examined the role of splenic dendritic cells in immune response to Toxoplasma gondii infection in SAG1 (P30+) transgenic mice by investigating the kinetics of intracellular cytokines expression of IL-4, IL-10, IL-12 and IFN-γ by intracellular cytokine staining (ICS) using flow cytometry, and compared the results to those of ...

  10. Fractal analysis of electrolytically-deposited palladium hydride dendrites

    International Nuclear Information System (INIS)

    Bursill, L.A.; Julin, Peng; Xudong, Fan.

    1990-01-01

    The fractal scaling characteristics of the surface profile of electrolytically-deposited palladium hydride dendritic structures have been obtained using conventional and high resolution transmission electron microscopy. The results are in remarkable agreement with the modified diffusion-limited aggregation model. 19 refs., 3 tabs., 13 figs

  11. Modulation of synaptic potentials and cell excitability by dendritic ...

    Indian Academy of Sciences (India)

    The nucleus accumbens (NAc), a critical structure of the brain reward circuit, is implicated in normal goal-directed behaviour and learning as well as pathological conditions like schizophrenia and addiction. Its major cellular substrates, the medium spiny (MS) neurons, possess a wide variety of dendritic active conductances ...

  12. Dendritic cell-tumor cell hybrids and immunotherapy

    DEFF Research Database (Denmark)

    Cathelin, Dominique; Nicolas, Alexandra; Bouchot, André

    2011-01-01

    Dendritic cells (DC) are professional antigen-presenting cells currently being used as a cellular adjuvant in cancer immunotherapy strategies. Unfortunately, DC-based vaccines have not demonstrated spectacular clinical results. DC loading with tumor antigens and DC differentiation and activation...

  13. Cryotherapy in Dendritic Keratitis. | Mpyet | Nigerian Journal of ...

    African Journals Online (AJOL)

    This study evaluates the effectiveness of cryotherapy in the treatment of Dendritic Keratitis where antiviral agents are not available. The result show some improvement in visual acuity while one patient has a drop in vision. The extent of corneal scarring appears to depend on the duration of the disease and extent of stroma ...

  14. The effects of renal transplantation on circulating dendritic cells

    NARCIS (Netherlands)

    D.A. Hesselink (Dennis); L.M.B. Vaessen (Leonard); W.C.J. Hop (Wim); W. Schoordijk-Verschoor (Wenda); J.N.M. IJzermans (Jan); C.C. Baan (Carla); W. Weimar (Willem)

    2005-01-01

    textabstractThe effects of immunosuppressive agents on T cell function have been well characterized but virtually nothing is known about the effects of renal transplantation on human dendritic cells (DCs). With the use of flow cytometry, we studied the kinetics of myeloid and plasmacytoid DCs in

  15. Blastic Plasmacytoid Dendritic Cell Leukemia in a Black Malian

    African Journals Online (AJOL)

    2017-06-28

    Jun 28, 2017 ... (BPDCN) is an acute myeloblastic leukemia (AML) characterized by the clonal proliferation of precursors of plasmacytoid dendritic cells. It is categorized as an acute myeloid neoplasm by the 2008 world health organization classification of neoplasms. Over 90% of cases present with skin lesions in the form ...

  16. Dendritic cell vaccines in melanoma: from promise to proof?

    NARCIS (Netherlands)

    Lesterhuis, W. J.; Aarntzen, E. H. J. G.; de Vries, I. J. M.; Schuurhuis, D. H.; Figdor, C. G.; Adema, G. J.; Punt, C. J. A.

    2008-01-01

    Dendritic cells (DC) are the directors of the immune system, capable of inducing tumour antigen-specific T- and B-cell responses. As such, they are currently applied in clinical studies in cancer patients. Early small clinical trials showed promising results, with frequent induction of anti-cancer

  17. Genetically engineered dendritic cell-based cancer vaccines

    Czech Academy of Sciences Publication Activity Database

    Bubeník, Jan

    2001-01-01

    Roč. 18, č. 3 (2001), s. 475-478 ISSN 1019-6439 R&D Projects: GA MZd NC5526 Keywords : dendritic cells * tumour vaccines Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.330, year: 2001

  18. Modulation of synaptic potentials and cell excitability by dendritic

    Indian Academy of Sciences (India)

    Its major cellular substrates, the medium spiny (MS) neurons, possess a wide variety of dendritic active conductances that may modulate the excitatory post synaptic potentials (EPSPs) and cell excitability. We examine this issue using a biophysically detailed 189-compartment stylized model of the NAc MS neuron, ...

  19. Innate signaling and regulation of Dendritic cell immunity

    NARCIS (Netherlands)

    van Vliet, Sandra J.; den Dunnen, Jeroen; Gringhuis, Sonja I.; Geijtenbeek, Teunis Bh; van Kooyk, Yvette

    2007-01-01

    Dendritic cells are crucial in pathogen recognition and induction of specific immune responses to eliminate pathogens from the infected host. Host recognition of invading microorganisms relies on evolutionarily conserved, germline-encoded pattern-recognition receptors (PRRs) that are expressed by

  20. Dendritic cell subsets digested: RNA sensing makes the difference!

    NARCIS (Netherlands)

    Buschow, S.I.; Figdor, C.G.

    2010-01-01

    In this issue of Immunity, Luber et al. (2010) report a comprehensive quantitative proteome of in vivo mouse spleen dendritic cell (DC) subsets: a data set of encyclopedic value already revealing that DC subsets exploit different RNA sensors for virus recognition.

  1. Modulation of synaptic potentials and cell excitability by dendritic ...

    Indian Academy of Sciences (India)

    Modulation of synaptic potentials and cell excitability by dendritic. KIR and KAs channels in nucleus accumbens medium spiny neurons: A computational study. JESSY JOHN* and ROHIT MANCHANDA. Biomedical Engineering group, Department of Biosciences and Bioengineering, Indian Institute of Technology. Bombay ...

  2. Menage a trois: Borrelia, dendritic cells, and tick saliva interactions

    NARCIS (Netherlands)

    Mason, Lauren M. K.; Veerman, Christiaan C.; Geijtenbeek, Teunis B. H.; Hovius, Joppe W. R.

    2014-01-01

    Borrelia burgdorferi sensu lato, the causative agent of Lyme borreliosis, is inoculated into the skin during an lxodes tick bite where it is recognised and captured by dendritic cells (DCs). However, considering the propensity of Borrelia to disseminate, it would appear that DCs fall short in

  3. Investigating Human Dendritic Cell Immune Responses to Borrelia burgdorferi

    NARCIS (Netherlands)

    Mason, Lauren M. K.; Hovius, Joppe W. R.

    2018-01-01

    Dendritic cells (DCs) are professional antigen-presenting cells that recognize and phagocytose pathogens, and help to orchestrate adaptive immune responses to combat them. DCs are abundant in the skin where Borrelia burgdorferi first enters the body during a tick bite, and are thus critical in

  4. Cognitive restraint, uncontrolled eating and emotional eating: correlations between parent and adolescent. : Familial resemblance in eating behavior

    OpenAIRE

    De Lauzon-Guillain , Blandine; Romon , Monique; Musher-Eizenman , Dara; Heude , Barbara; Basdevant , Arnaud; Charles , Marie-Aline

    2009-01-01

    International audience; The purpose of this study was to examine, in a general population, the resemblance in eating behaviour between adolescents and their parents. This study was based on the first examination of a community-based epidemiological study in Northern France. Subjects were offspring aged 14-22 years (135 boys and 125 girls) and their parents (174 fathers and 205 mothers). The Three-Factor Eating Questionnaire Revised 18-item version (TFEQ-R18) identified three aspects of eating...

  5. Age and Gender Differences in Facial Attractiveness, but Not Emotion Resemblance, Contribute to Age and Gender Stereotypes

    OpenAIRE

    Palumbo, Rocco; Adams, Reginald B.; Hess, Ursula; Kleck, Robert E.; Zebrowitz, Leslie

    2017-01-01

    Considerable research has shown effects of facial appearance on trait impressions and group stereotypes. We extended those findings in two studies that investigated the contribution of resemblance to emotion expressions and attractiveness to younger adults (YA) and older adults (OA) age and gender stereotypes on the dimensions of warmth and competence. Using connectionist modeling of facial metrics of 240 neutral younger and older faces, Study 1 found that, neutral expression older faces or f...

  6. Dendritic development of Drosophila high order visual system neurons is independent of sensory experience

    Directory of Open Access Journals (Sweden)

    Reuter John E

    2003-06-01

    Full Text Available Abstract Background The complex and characteristic structures of dendrites are a crucial part of the neuronal architecture that underlies brain function, and as such, their development has been a focal point of recent research. It is generally believed that dendritic development is controlled by a combination of endogenous genetic mechanisms and activity-dependent mechanisms. Therefore, it is of interest to test the relative contributions of these two types of mechanisms towards the construction of specific dendritic trees. In this study, we make use of the highly complex Vertical System (VS of motion sensing neurons in the lobula plate of the Drosophila visual system to gauge the importance of visual input and synaptic activity to dendritic development. Results We find that the dendrites of VS1 neurons are unchanged in dark-reared flies as compared to control flies raised on a 12 hour light, 12 hour dark cycle. The dendrites of these flies show no differences from control in dendrite complexity, spine number, spine density, or axon complexity. Flies with genetically ablated eyes show a slight but significant reduction in the complexity and overall length of VS1 dendrites, although this effect may be due to a reduction in the overall size of the dendritic field in these flies. Conclusions Overall, our results indicate no role for visual experience in the development of VS dendrites, while spontaneous activity from photoreceptors may play at most a subtle role in the formation of fully complex dendrites in these high-order visual processing neurons.

  7. Phenotypes of Non-Attached Pseudomonas aeruginosa Aggregates Resemble Surface Attached Biofilm

    DEFF Research Database (Denmark)

    Alhede, Morten; Kragh, Kasper Nørskov; Qvortrup, Klaus

    2011-01-01

    For a chronic infection to be established, bacteria must be able to cope with hostile conditions such as low iron levels, oxidative stress, and clearance by the host defense, as well as antibiotic treatment. It is generally accepted that biofilm formation facilitates tolerance to these adverse co...... media; soft tissue fillers and non-healing wounds, and we propose that aggregated cells exhibit enhanced survival in the hostile host environment, compared with non-aggregated bacterial populations....... of age, both aggregates and flow-cell biofilm had the same slow growth rate as a stationary phase shaking cultures. Internal structures of the aggregates matrix components and their capacity to survive otherwise lethal treatments with antibiotics (referred to as tolerance) and resistance to phagocytes...

  8. Histamine receptor 2 modifies dendritic cell responses to microbial ligands.

    Science.gov (United States)

    Frei, Remo; Ferstl, Ruth; Konieczna, Patrycja; Ziegler, Mario; Simon, Tunde; Rugeles, Tulia Mateus; Mailand, Susanne; Watanabe, Takeshi; Lauener, Roger; Akdis, Cezmi A; O'Mahony, Liam

    2013-07-01

    The induction of tolerance and protective immunity to microbes is significantly influenced by host- and microbiota-derived metabolites, such as histamine. We sought to identify the molecular mechanisms for histamine-mediated modulation of pattern recognition receptor signaling. Human monocyte-derived dendritic cells (MDDCs), myeloid dendritic cells, and plasmacytoid dendritic cells were examined. Cytokine secretion, gene expression, and transcription factor activation were measured after stimulation with microbial ligands and histamine. Histamine receptor 2 (H₂R)-deficient mice, histamine receptors, and their signaling pathways were investigated. Histamine suppressed MDDC chemokine and proinflammatory cytokine secretion, nuclear factor κB and activator protein 1 activation, mitogen-activated protein kinase phosphorylation, and T(H)1 polarization of naive lymphocytes, whereas IL-10 secretion was enhanced in response to LPS and Pam3Cys. Histamine also suppressed LPS-induced myeloid dendritic cell TNF-α secretion and suppressed CpG-induced plasmacytoid dendritic cell IFN-α gene expression. H₂R signaling through cyclic AMP and exchange protein directly activated by cyclic AMP was required for the histamine effect on LPS-induced MDDC responses. Lactobacillus rhamnosus, which secretes histamine, significantly suppressed Peyer patch IL-2, IL-4, IL-5, IL-12, TNF-α, and GM-CSF secretion in wild-type but not H₂R-deficient animals. Both host- and microbiota-derived histamine significantly alter the innate immune response to microbes through H₂R. Copyright © 2013 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  9. Influence of Dendritic Cells on B-Cell Responses during HIV Infection

    Directory of Open Access Journals (Sweden)

    Johanne Poudrier

    2012-01-01

    Full Text Available Dendritic cells (DCs modulate B-cell differentiation, activation, and survival mainly through production of growth factors such as B lymphocyte stimulator (BLyS/BAFF. DC populations have been reported to be affected in number, phenotype and function during HIV infection and such alterations may contribute to the dysregulation of the B-cell compartment. Herein, we reflect on the potential impact of DC on the pathogenesis of HIV-related B cell disorders, and how DC status may modulate the outcome of mucosal B cell responses against HIV, which are pivotal to the control of disease. A concept that could be extrapolated to the overall outcome of HIV disease, whereby control versus progression may reside in the host’s capacity to maintain DC homeostasis at mucosal sites, where DC populations present an inherent capacity of modulating the balance between tolerance and protection, and are amongst the earliest cell types to be exposed to the virus.

  10. Effects of material non-linearity on the residual stresses in a dendritic silicon crystal ribbon

    Science.gov (United States)

    Ray, Sujit K.; Utku, Senol

    1990-01-01

    Thermal stresses developed in a dendritic silicon crystal ribbon have been shown to cause plastic deformation and residual stresses in the ribbon. This paper presents an implementation of a numerical model proposed for thermoelastoplastic behavior of a material. The model has been used to study the effects of plasticity of silicon on the residual stresses. The material properties required to implement this model are all assumed, and the response of the material to the variations in these assumed parameters of the constitutive law and in the finite element mesh is investigated. The steady state growth process is observed to be periodic with nonzero residual stresses. Numerical difficulties are also encountered in the computer solution process, resulting in sharp jumps and large oscillations in the stress responses.

  11. Effective antitumor immunity against murine gliomas using dendritic cells transduced with hTERTC27 recombinant adenovirus

    OpenAIRE

    GONG, HAN-XIAN; HE, LEI; LI, XIANG-PEN; WANG, YI-DONG; LI, YI; HUANG, JUN-JIAN; WANG, ZILING; XIE, DAN; KUNG, HSIANG-FU; PENG, YING

    2011-01-01

    hTERTC27, a 27-kDa hTERT C-terminal polypeptide has been demonstrated to cause hTERT-positive HeLa cell apoptosis and inhibits the growth of mouse melanoma. hTERTC27 has been associated with telomere dysfunction, regulation of gene-regulated apoptosis, the cell cycle and activation of natural killer (NK) cells, but its mechanism of action is not fully understood. Here, we report that dendritic cells (DCs) transduced with hTERTC27 can increase T-cell proliferation, and augment the concentratio...

  12. DC-SIGN, a C-type lectin on dendritic cells that unveils many aspects of dendritic cell biology

    NARCIS (Netherlands)

    Geijtenbeek, Teunis B. H.; Engering, Anneke; van Kooyk, Yvette

    2002-01-01

    Dendritic cells (DC) are present in essentially every tissue where they operate at the interface of innate and acquired immunity by recognizing pathogens and presenting pathogen-derived peptides to T cells. It is becoming clear that not all C-type lectins on DC serve as antigen receptors recognizing

  13. Equine dendritic cells generated with horse serum have enhanced functionality in comparison to dendritic cells generated with fetal bovine serum.

    Science.gov (United States)

    Ziegler, Anja; Everett, Helen; Hamza, Eman; Garbani, Mattia; Gerber, Vinzenz; Marti, Eliane; Steinbach, Falko

    2016-11-15

    Dendritic cells are professional antigen-presenting cells that play an essential role in the initiation and modulation of T cell responses. They have been studied widely for their potential clinical applications, but for clinical use to be successful, alternatives to xenogeneic substances like fetal bovine serum (FBS) in cell culture need to be found. Protocols for the generation of dendritic cells ex vivo from monocytes are well established for several species, including horses. Currently, the gold standard protocol for generating dendritic cells from monocytes across various species relies upon a combination of GM-CSF and IL-4 added to cell culture medium which is supplemented with FBS. The aim of this study was to substitute FBS with heterologous horse serum. For this purpose, equine monocyte-derived dendritic cells (eqMoDC) were generated in the presence of horse serum or FBS and analysed for the effect on morphology, phenotype and immunological properties. Changes in the expression of phenotypic markers (CD14, CD86, CD206) were assessed during dendritic cell maturation by flow cytometry. To obtain a more complete picture of the eqMoDC differentiation and assess possible differences between FBS- and horse serum-driven cultures, a transcriptomic microarray analysis was performed. Lastly, immature eqMoDC were primed with a primary antigen (ovalbumin) or a recall antigen (tetanus toxoid) and, after maturation, were co-cultured with freshly isolated autologous CD5 + T lymphocytes to assess their T cell stimulatory capacity. The microarray analysis demonstrated that eqMoDC generated with horse serum were indistinguishable from those generated with FBS. However, eqMoDC incubated with horse serum-supplemented medium exhibited a more characteristic dendritic cell morphology during differentiation from monocytes. A significant increase in cell viability was also observed in eqMoDC cultured with horse serum. Furthermore, eqMoDC generated in the presence of horse serum

  14. A novel low-temperature chemical solution route for straight and dendrite-like ZnO nanostructures

    International Nuclear Information System (INIS)

    Zhang Hui; Du Ning; Wu Jianbo; Ma, Xiangyang; Yang Deren; Zhang Xiaobin; Yang Zhiqing

    2007-01-01

    The straight and dendrite-like growths of ZnO have been completely and simply controlled by the status of ZnO seed instead of surfactant, template, oriented attachment, and ZnO buffer layer on the substrate in the chemical reaction synthesis of ZnO nanostructures. The monodisperse ZnO seeds, which are prepared by in situ quickly injecting the cool mixed zinc acetate and potassium hydrate ethanol solution into the hot matrix aqueous solution of zinc nitrate hydrate and diethylenetriamine at 95 deg. C, improve the straight growth and lots of uniform, straight, and single-crystalline ZnO nanorods with about 20-30 nm in diameter and 300 nm in length are achieved. While, the aggregated ZnO seeds, which are prepared by dropwise adding potassium hydrate ethanol solution into zinc acetate ethanol solution at 60 deg. C for 3 h, result in the dendrite-like growth and the bur-like ZnO nanostructures consisting of hundreds of nanorods with about 30-50 nm in diameter and several micrometers in length are formed. Furthermore, the approach presented here provides a simple, low-cost, environmental-friendly and high efficiency route to synthesize the high quality ZnO nanorods and bur-like ZnO nanostructures

  15. Pre-autoimmune thyroid abnormalities in the biobreeding diabetes-prone (BB-DP) rat: a possible relation with the intrathyroid accumulation of dendritic cells and the initiation of the thyroid autoimmune response

    NARCIS (Netherlands)

    P.J. Simons (Peter); F.G. Delemarre; P.H. Jeucken; H.A. Drexhage (Hemmo)

    1998-01-01

    textabstractThyroid autoimmune reactions start with an accumulation of mainly dendritic cells in the thyroid. There is increasing evidence that, apart from being antigen-presenting cells, they are also able to control the growth and hormone synthesis of neighbouring

  16. A Shigella boydii bacteriophage which resembles Salmonella phage ViI

    Directory of Open Access Journals (Sweden)

    She Yi-Min

    2011-05-01

    Full Text Available Abstract Background Lytic bacteriophages have been applied successfully to control the growth of various foodborne pathogens. Sequencing of their genomes is considered as an important preliminary step to ensure their safety prior to food applications. Results The lytic bacteriophage, ΦSboM-AG3, targets the important foodborne pathogen, Shigella. It is morphologically similar to phage ViI of Salmonella enterica serovar Typhi and a series of phages of Acinetobacter calcoaceticus and Rhizobium meliloti. The complete genome of ΦSboM-AG3 was determined to be 158 kb and was terminally redundant and circularly permuted. Two hundred and sixteen open reading frames (ORFs were identified and annotated, most of which displayed homology to proteins of Salmonella phage ViI. The genome also included four genes specifying tRNAs. Conclusions This is the first time that a Vi-specific phage for Shigella has been described. There is no evidence for the presence of virulence and lysogeny-associated genes. In conclusion, the genome analysis of ΦSboM-AG3 indicates that this phage can be safely used for biocontrol purposes.

  17. Analysis of growth characteristics in short-term divergently selected ...

    African Journals Online (AJOL)

    weeks of age body weight in divergent lines of Japanese quail. Growth curves for both sexes within each selection group resembled the general sigmoid shape of a typical growth curve. Gompertz model curves and the observed growth curves were ...

  18. Surfactant Protein D modulates HIV infection of both T-cells and dendritic cells.

    Directory of Open Access Journals (Sweden)

    Jens Madsen

    Full Text Available Surfactant Protein D (SP-D is an oligomerized C-type lectin molecule with immunomodulatory properties and involvement in lung surfactant homeostasis in the respiratory tract. SP-D binds to the enveloped viruses, influenza A virus and respiratory syncytial virus and inhibits their replication in vitro and in vivo. SP-D has been shown to bind to HIV via the HIV envelope protein gp120 and inhibit infectivity in vitro. Here we show that SP-D binds to different strains of HIV (BaL and IIIB and the binding occurs at both pH 7.4 and 5.0 resembling physiological relevant pH values found in the body and the female urogenital tract, respectively. The binding of SP-D to HIV particles and gp120 was inhibited by the presence of several hexoses with mannose found to be the strongest inhibitor. Competition studies showed that soluble CD4 and CVN did not interfere with the interaction between SP-D and gp120. However, soluble recombinant DC-SIGN was shown to inhibit the binding between SP-D and gp120. SP-D agglutinated HIV and gp120 in a calcium dependent manner. SP-D inhibited the infectivity of HIV strains at both pH values of 7.4 and 5.0 in a concentration dependent manner. The inhibition of the infectivity was abolished by the presence of mannose. SP-D enhanced the binding of HIV to immature monocyte derived dendritic cells (iMDDCs and was also found to enhance HIV capture and transfer to the T-cell like line PM1. These results suggest that SP-D can bind to and inhibit direct infection of T-cells by HIV but also enhance the transfer of infectious HIV particles from DCs to T-cells in vivo.

  19. CD9 Regulates Major Histocompatibility Complex Class II Trafficking in Monocyte-Derived Dendritic Cells.

    Science.gov (United States)

    Rocha-Perugini, Vera; Martínez Del Hoyo, Gloria; González-Granado, José María; Ramírez-Huesca, Marta; Zorita, Virginia; Rubinstein, Eric; Boucheix, Claude; Sánchez-Madrid, Francisco

    2017-08-01

    Antigen presentation by dendritic cells (DCs) stimulates naive CD4 + T cells, triggering T cell activation and the adaptive arm of the immune response. Newly synthesized major histocompatibility complex class II (MHC-II) molecules accumulate at MHC-II-enriched endosomal compartments and are transported to the plasma membrane of DCs after binding to antigenic peptides to enable antigen presentation. In DCs, MHC-II molecules are included in tetraspanin-enriched microdomains (TEMs). However, the role of tetraspanin CD9 in these processes remains largely undefined. Here, we show that CD9 regulates the T cell-stimulatory capacity of granulocyte-macrophage colony-stimulating factor (GM-CSF)-dependent bone marrow-derived DCs (BMDCs), without affecting antigen presentation by fms-like tyrosine kinase 3 ligand (Flt3L)-dependent BMDCs. CD9 knockout (KO) GM-CSF-dependent BMDCs, which resemble monocyte-derived DCs (MoDCs), induce lower levels of T cell activation than wild-type DCs, and this effect is related to a reduction in MHC-II surface expression in CD9-deficient MoDCs. Importantly, MHC-II targeting to the plasma membrane is largely impaired in immature CD9 KO MoDCs, in which MHC-II remains arrested in acidic intracellular compartments enriched in LAMP-1 (lysosome-associated membrane protein 1), and MHC-II internalization is also blocked. Moreover, CD9 participates in MHC-II trafficking in mature MoDCs, regulating its endocytosis and recycling. Our results demonstrate that the tetraspanin CD9 specifically regulates antigenic presentation in MoDCs through the regulation of MHC-II intracellular trafficking. Copyright © 2017 American Society for Microbiology.

  20. Leaf and floral heating in cold climates: do sub-Antarctic megaherbs resemble tropical alpine giants?

    Directory of Open Access Journals (Sweden)

    Lorna Little

    2016-08-01

    Full Text Available High latitude and altitude floras are characterized by low-statured, small, wind-pollinated plants, which mainly reproduce by self-pollination or asexual reproduction. However, at odds with this are some sub-Antarctic islands that have plant species with giant growth forms and large, brightly coloured flowers which require insect visitation for pollination. The size, colour and shape of the inflorescences and leaves of these megaherbs suggest thermal benefits similar to giant tropical alpine plants of equatorial Africa, South America and Hawaii. We evaluated whether heating occurs in sub-Antarctic megaherbs, and to what extent it is related to environmental variables. We measured leaf and inflorescence temperature in six sub-Antarctic megaherb species on Campbell Island, latitude 52.3°S, New Zealand Biological Region. Using thermal imaging techniques, in combination with measurement of solar radiation, ambient air temperature, wind speed, wind chill and humidity, we assessed environmental influences on leaf and floral heating. We found that leaf and inflorescence temperatures of all megaherbs were higher than simultaneously measured ambient temperatures. Greatest heating was seen in Pleurophyllum speciosum, with observed leaves 9°C higher, and inflorescences nearly 11°C higher, than ambient temperature. Heating was highly correlated with brief, unpredictable periods of solar radiation, and occurred most rapidly in species with hairy, corrugated leaves and darkly pigmented, densely packed inflorescences. This is the first evidence that floral and leaf heating occurs in sub-Antarctic megaherbs, and suggests that leaf hairiness, flower colour and shape could provide thermal benefits like those seen in tropical alpine megaherbs.

  1. REMOD: a computational tool for remodeling neuronal dendrites

    Directory of Open Access Journals (Sweden)

    Panagiotis Bozelos

    2014-05-01

    Full Text Available In recent years, several modeling studies have indicated that dendritic morphology is a key determinant of how individual neurons acquire a unique signal processing profile. The highly branched dendritic structure that originates from the cell body, explores the surrounding 3D space in a fractal-like manner, until it reaches a certain amount of complexity. Its shape undergoes significant alterations not only in various neuropathological conditions, but in physiological, too. Yet, despite the profound effect that these alterations can have on neuronal function, the causal relationship between structure and function remains largely elusive. The lack of a systematic approach for remodeling neuronal cells and their dendritic trees is a key limitation that contributes to this problem. In this context, we developed a computational tool that allows the remodeling of any type of neurons, given a set of exemplar morphologies. The tool is written in Python and provides a simple GUI that guides the user through various options to manipulate selected neuronal morphologies. It provides the ability to load one or more morphology files (.swc or .hoc and choose specific dendrites to operate one of the following actions: shrink, remove, extend or branch (as shown in Figure 1. The user retains complete control over the extent of each alteration and if a chosen action is not possible due to pre-existing structural constraints, appropriate warnings are produced. Importantly, the tool can also be used to extract morphology statistics for one or multiple morphologies, including features such as the total dendritic length, path length to the root, branch order, diameter tapering, etc. Finally, an experimental utility enables the user to remodel entire dendritic trees based on preloaded statistics from a database of cell-type specific neuronal morphologies. To our knowledge, this is the first tool that allows (a the remodeling of existing –as opposed to the de novo

  2. Cigarette smoke promotes dendritic cell accumulation in COPD; a Lung Tissue Research Consortium study

    Directory of Open Access Journals (Sweden)

    Yi Eunhee S

    2010-04-01

    Full Text Available Abstract Background Abnormal immune responses are believed to be highly relevant in the pathogenesis of chronic obstructive pulmonary disease (COPD. Dendritic cells provide a critical checkpoint for immunity by their capacity to both induce and suppress immunity. Although evident that cigarette smoke, the primary cause of COPD, significantly influences dendritic cell functions, little is known about the roles of dendritic cells in the pathogenesis of COPD. Methods The extent of dendritic cell infiltration in COPD tissue specimens was determined using immunohistochemical localization of CD83+ cells (marker of matured myeloid dendritic cells, and CD1a+ cells (Langerhans cells. The extent of tissue infiltration with Langerhans cells was also determined by the relative expression of the CD207 gene in COPD versus control tissues. To determine mechanisms by which dendritic cells accumulate in COPD, complimentary studies were conducted using monocyte-derived human dendritic cells exposed to cigarette smoke extract (CSE, and dendritic cells extracted from mice chronically exposed to cigarette smoke. Results In human COPD lung tissue, we detected a significant increase in the total number of CD83+ cells, and significantly higher amounts of CD207 mRNA when compared with control tissue. Human monocyte-derived dendritic cells exposed to CSE (0.1-2% exhibited enhanced survival in vitro when compared with control dendritic cells. Murine dendritic cells extracted from mice exposed to cigarette smoke for 4 weeks, also demonstrated enhanced survival compared to dendritic cells extracted from control mice. Acute exposure of human dendritic cells to CSE induced the cellular pro-survival proteins heme-oxygenase-1 (HO-1, and B cell lymphoma leukemia-x(L (Bcl-xL, predominantly through oxidative stress. Although activated human dendritic cells conditioned with CSE expressed diminished migratory CCR7 expression, their migration towards the CCR7 ligand CCL21 was not

  3. Toll-like receptor 7/8 agonists stimulate plasmacytoid dendritic cells to initiate TH17-deviated acute contact dermatitis in human subjects.

    Science.gov (United States)

    Garzorz-Stark, Natalie; Lauffer, Felix; Krause, Linda; Thomas, Jenny; Atenhan, Anne; Franz, Regina; Roenneberg, Sophie; Boehner, Alexander; Jargosch, Manja; Batra, Richa; Mueller, Nikola S; Haak, Stefan; Groß, Christina; Groß, Olaf; Traidl-Hoffmann, Claudia; Theis, Fabian J; Schmidt-Weber, Carsten B; Biedermann, Tilo; Eyerich, Stefanie; Eyerich, Kilian

    2018-04-01

    A standardized human model to study early pathogenic events in patients with psoriasis is missing. Activation of Toll-like receptor 7/8 by means of topical application of imiquimod is the most commonly used mouse model of psoriasis. We sought to investigate the potential of a human imiquimod patch test model to resemble human psoriasis. Imiquimod (Aldara 5% cream; 3M Pharmaceuticals, St Paul, Minn) was applied twice a week to the backs of volunteers (n = 18), and development of skin lesions was monitored over a period of 4 weeks. Consecutive biopsy specimens were taken for whole-genome expression analysis, histology, and T-cell isolation. Plasmacytoid dendritic cells (pDCs) were isolated from whole blood, stimulated with Toll-like receptor 7 agonist, and analyzed by means of extracellular flux analysis and real-time PCR. We demonstrate that imiquimod induces a monomorphic and self-limited inflammatory response in healthy subjects, as well as patients with psoriasis or eczema. The clinical and histologic phenotype, as well as the transcriptome, of imiquimod-induced inflammation in human skin resembles acute contact dermatitis rather than psoriasis. Nevertheless, the imiquimod model mimics the hallmarks of psoriasis. In contrast to classical contact dermatitis, in which myeloid dendritic cells sense haptens, pDCs are primary sensors of imiquimod. They respond with production of proinflammatory and T H 17-skewing cytokines, resulting in a T H 17 immune response with IL-23 as a key driver. In a proof-of-concept setting systemic treatment with ustekinumab diminished imiquimod-induced inflammation. In human subjects imiquimod induces contact dermatitis with the distinctive feature that pDCs are the primary sensors, leading to an IL-23/T H 17 deviation. Despite these shortcomings, the human imiquimod model might be useful to investigate early pathogenic events and prove molecular concepts in patients with psoriasis. Copyright © 2017 The Authors. Published by Elsevier

  4. Murine and Human Model Systems for the Study of Dendritic Cell Immunobiology.

    Science.gov (United States)

    Hargadon, Kristian M

    2016-01-01

    Dendritic cells are a population of innate immune cells that possess their own effector functions as well as numerous regulatory properties that shape the activity of other innate and adaptive cells of the immune system. Following their development from either lymphoid or myeloid progenitors, the function of dendritic cells is tightly linked to their maturation and activation status. Differentiation into specialized subsets of dendritic cells also contributes to the diverse immunologic functions of these cells. Because of the key role played by dendritic cells in the regulation of both immune tolerance and activation, significant efforts have been focused on understanding dendritic cell biology. This review highlights the model systems currently available to study dendritic cell immunobiology and emphasizes the advantages and disadvantages to each system in both murine and human settings. In particular, in vitro cell culture systems involving immortalized dendritic cell lines, ex vivo systems for differentiating and expanding dendritic cells from their precursor populations, and systems for expanding, ablating, and manipulating dendritic cells in vivo are discussed. Emphasis is placed on the contribution of these systems to our current understanding of the development, function, and immunotherapeutic applications of dendritic cells, and insights into how these models might be extended in the future to answer remaining questions in the field are discussed.

  5. Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases.

    Science.gov (United States)

    Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

    2009-11-01

    Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. Microparticles generated from endothelial cell lines, platelets or activated T cells were incubated with human plasmacytoid dendritic cells sorted from healthy donor blood or with monocyte-derived dendritic cells. Dendritic cell maturation was evaluated by flow cytometry, cytokine secretion as well as naive T-cell activation and polarization. Labeled microparticles were also used to study cellular interactions. Endothelial microparticles induced plasmacytoid dendritic cell maturation. In contrast, conventional dendritic cells were resistant to endothelial microparticle-induced maturation. In addition to upregulation of co-stimulatory molecules, endothelial microparticle-matured plasmacytoid dendritic cells secreted inflammatory cytokines (interleukins 6 and 8, but no interferon-alpha) and also induced allogeneic naive CD4(+) T cells to proliferate and to produce type 1 cytokines such as interferon-gamma and tumor necrosis factor-alpha. Endothelial microparticle endocytosis by plasmacytoid dendritic cells appeared to be required for plasmacytoid dendritic cell maturation. Importantly, the ability of endothelial microparticles to induce plasmacytoid dendritic cells to mature was specific as microparticles derived from activated T cells or platelets (the major source of circulating microparticules in healthy subjects) did not induce such plasmacytoid dendritic cell maturation. Our data show that endothelial microparticles specifically induce plasmacytoid dendritic cell maturation and production of inflammatory cytokines. This novel activation pathway may be implicated in various inflammatory disorders and

  6. Socioeconomic and Demographic Factors for Spousal Resemblance in Obesity Status and Habitual Physical Activity in the United States

    Directory of Open Access Journals (Sweden)

    Hsin-Jen Chen

    2014-01-01

    Full Text Available Studies suggested that the married population has an increased risk of obesity and assimilation between spouses’ body weight. We examined what factors may affect married spouses’ resemblance in weight status and habitual physical activity (HPA and the association of obesity/HPA with spouses’ sociodemoeconomic characteristics and lifestyles. Medical Expenditure Panel Survey data of 11,403 adult married couples in the US during years 2006–2008 were used. Absolute-scale difference and relative-scale resemblance indices (correlation and kappa coefficients in body mass index (BMI and HPA were estimated by couples’ socioeconomic and demographic characteristics. We found that spousal difference in BMI was smaller for couples with a lower household income, for who were both unemployed, and for older spouses. Correlation coefficient between spouses’ BMI was 0.24, differing by race/ethnicity and family size. Kappa coefficient for weight status (obesity: BMI ≥ 30, overweight: 30 > BMI ≥ 25 was 0.11 and 0.35 for HPA. Never-working women’s husbands had lower odds of obesity than employed women’s husbands (OR = 0.69 (95% CI = 0.53–0.89. Men’s unemployment status was associated with wives’ greater odds of obesity (OR = 1.31 (95% CI = 1.01–1.71. HPA was associated with men’s employment status and income level, but not with women’s. The population representative survey showed that spousal resemblance in weight status and HPA varied with socioeconomic and demographic factors.

  7. Synaptic clustering within dendrites: an emerging theory of memory formation.

    Science.gov (United States)

    Kastellakis, George; Cai, Denise J; Mednick, Sara C; Silva, Alcino J; Poirazi, Panayiota

    2015-03-01

    It is generally accepted that complex memories are stored in distributed representations throughout the brain, however the mechanisms underlying these representations are not understood. Here, we review recent findings regarding the subcellular mechanisms implicated in memory formation, which provide evidence for a dendrite-centered theory of memory. Plasticity-related phenomena which affect synaptic properties, such as synaptic tagging and capture, synaptic clustering, branch strength potentiation and spinogenesis provide the foundation for a model of memory storage that relies heavily on processes operating at the dendrite level. The emerging picture suggests that clusters of functionally related synapses may serve as key computational and memory storage units in the brain. We discuss both experimental evidence and theoretical models that support this hypothesis and explore its advantages for neuronal function. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. THE CHEMOIMMUNOTHERAPY BASED ON DENDRITIC CELLS AND CISPLATIN IN EXPERIMENT

    Directory of Open Access Journals (Sweden)

    Gorbach O. I.

    2014-08-01

    Full Text Available The aim of the study was to develop a scheme of combined chemoimmunotherapy and to investigate antitumor and immunomodulatory activity of chemoimmunotherapy regimen using the vaccine based on dendritic cells and low-doses of cisplatin in CBA mice with sarcoma-37. Maximal antitumor and immunomodulatory effects were observed after application of the vaccine based on dendritic cells in combination with doses of cisplatin concentration of 2 mg/kg. Among significant immunomodulatory effects of combination therapy it has to be noted the increased functional activity of natural immunity,in particular, enhancing of cytotoxic activity of natural killer cells and the ability of peritoneal macrophages, neutrophils and spleen macrophages to increase their absorbing activity and to produce the active oxygen forms. The obtained results prove the expediency of combining of chemo- and immunotherapeutic methods for the development of more effective approaches to prevent recurrence and metastasis after primary treatment of cancer patients.

  9. EphB/syndecan-2 signaling in dendritic spine morphogenesis

    DEFF Research Database (Denmark)

    Ethell, I M; Irie, F; Kalo, M S

    2001-01-01

    We previously reported that the cell surface proteoglycan syndecan-2 can induce dendritic spine formation in hippocampal neurons. We demonstrate here that the EphB2 receptor tyrosine kinase phosphorylates syndecan-2 and that this phosphorylation event is crucial for syndecan-2 clustering and spine...... formation. Syndecan-2 is tyrosine phosphorylated and forms a complex with EphB2 in mouse brain. Dominant-negative inhibition of endogenous EphB receptor activities blocks clustering of endogenous syndecan-2 and normal spine formation in cultured hippocampal neurons. This is the first evidence that Eph...... receptors play a physiological role in dendritic spine morphogenesis. Our observations suggest that spine morphogenesis is triggered by the activation of Eph receptors, which causes tyrosine phosphorylation of target molecules, such as syndecan-2, in presumptive spines....

  10. Building on Dendritic Cell Subsets to Improve Cancer Vaccines

    OpenAIRE

    Palucka, Karolina; Ueno, Hideki; Zurawski, Gerard; Fay, Joseph; Banchereau, Jacques

    2010-01-01

    T cells can reject established tumors when adoptively transferred into patients, thereby demonstrating that the immune system can be harnessed for cancer therapy. However, such passive immunotherapy is unlikely to maintain memory T cells that might control tumor outgrowth on the long term. Active immunotherapy with vaccines has the potential to induce tumor-specific effector and memory T cells. Vaccines act through dendritic cells (DCs) which induce, regulate and maintain T cell immunity. Cli...

  11. Immunohistochemical analysis of small plaque parapsoriasis: involvement of dendritic cells.

    Science.gov (United States)

    Zeybek, N Dilara; Asan, Esin; Erbil, A Hakan; Dagdeviren, Attila

    2008-01-01

    Small plaque parapsoriasis (SPP) is one of the cutaneous T-cell lymphoproliferative disorders. The aim of the present study was to show the antigenic profile of a subset of dendritic cells and lymphocytes in SPP in comparison with normal cells to provide data on the role of these two cell types in the pathogenesis of SPP. Skin biopsy specimens of lesions were obtained from 8 patients with SPP. Biopsies of the healthy skin from 9 control individuals were also analyzed. Immunohistochemistry was performed on the frozen tissue sections to reveal binding of anti-HLA Class II, anti-CD1a, anti-CD4, anti-CD8, anti-CD44, anti-CD45, and anti-CD68 monoclonal antibodies. There was a statistically significant increase in the number of CD1a(+), Langerhans cells (LCs), HLA-DR-immunoreactive and, CD1a-positive dermal dendritic cells and CD68(+) macrophages in the SPP group (p=0.008, 0.008, 0.002 and <0.0009, respectively). The number of lymphocytes positive for CD4, CD8 and CD45 was significantly higher than normal in the SPP group (p=0.015, <0.0009 and <0.0009, respectively). Our study demonstrates that both peptide- and lipid-based antigens are involved in the persistent antigenic exposure in SPP. Dendritic cells play a pivotal role in SPP by presenting antigens by both LC and dermal dendritic cells via MHC Class II and CD1a molecules. The CD68(+) macrophages are thought to be involved in the immune response in this pathology as an antigen-presenting cell.

  12. Utilization of oncoprotein-pulsed dendritic cells as tumor vaccines

    Czech Academy of Sciences Publication Activity Database

    Bubeník, Jan

    2001-01-01

    Roč. 127, č. 8 (2001), s. 463-466 ISSN 0171-5216 R&D Projects: GA MZd NC5526; GA MZd NC45011; GA ČR GA312/98/0826; GA ČR GA312/99/0542; GA ČR GA301/00/0114 Institutional research plan: CEZ:AV0Z5052915 Keywords : dendritic cells * tumor vaccines * oncoproteins Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.194, year: 2001

  13. Antithymocyte Globulin Induces a Tolerogenic Phenotype in Human Dendritic Cells

    OpenAIRE

    Roider, Tobias; Katzfu?, Michael; Matos, Carina; Singer, Katrin; Renner, Kathrin; Oefner, Peter J.; Dettmer-Wilde, Katja; Herr, Wolfgang; Holler, Ernst; Kreutz, Marina; Peter, Katrin

    2016-01-01

    Antithymocyte globulin (ATG) is used in the prevention of graft-versus-host disease during allogeneic hematopoietic stem cell transplantation. It is generally accepted that ATG mediates its immunosuppressive effect primarily via depletion of T cells. Here, we analyzed the impact of ATG-Fresenius (now Grafalon®) on human monocyte-derived dendritic cells (DC). ATG induced a semi-mature phenotype in DC with significantly reduced expression of CD14, increased expression of HLA-DR, and intermediat...

  14. The Thorny Side of Addiction: Adaptive Plasticity and Dendritic Spines

    Directory of Open Access Journals (Sweden)

    Patrick J. Mulholland

    2007-01-01

    Full Text Available Dendritic spines are morphologically specialized structures that receive the vast majority of central excitatory synaptic inputs. Studies have implicated changes in the size, shape, and number of dendritic spines in activity-dependent plasticity, and have further demonstrated that spine morphology is highly dependent on the dynamic organizational and scaffolding properties of its postsynaptic density (PSD. In vitro and in vivo models of experience-dependent plasticity have linked changes in the localization of glutamate receptors at the PSD with a molecular reorganization of the PSD and alterations in spine morphology. Chronic ethanol consumption results in adaptive changes in neuronal function that manifest as tolerance, physical dependence, and addiction. A potential mechanism supporting these adaptive changes that we recently identified is the homeostatic targeting of NR2B-containing NMDA receptors to the synapse. This increase is associated with and dependent on a corresponding increase in the localization of the scaffolding protein PSD-95 at the PSD, and with an actin-dependent increase in the size of dendritic spines. These observations led us to propose a molecular model for ethanol-induced plasticity at excitatory synapses in which increases in NR2B-containing NMDA receptors and PSD-95 at the PSD provide an expanded scaffolding platform for the recruitment and activation of signaling molecules that regulate spine actin dynamics, protein translation, and synaptic plasticity. This model is consistent with accumulating evidence that glutamatergic modulation of spine actin by the PSD plays a role in the aberrant plasticity of addiction.

  15. Dendritic-metasurface-based flexible broadband microwave absorbers

    Science.gov (United States)

    Wang, Mei; Weng, Bin; Zhao, Jing; Zhao, Xiaopeng

    2017-06-01

    Based on the dendritic metasurface model, a type of flexible and lightweight microwave absorber (MA) comprising resistance film array with dendritic slot (RFADS), dielectric material, and metal plate is proposed. A broadband absorptivity of >80% is obtained both from simulation and experiment at frequency ranges of 3.0-9.2 and 3.2-9.00 GHz, respectively. And the thickness of MA is 5 mm, which is only 0.05λ _{low}, or 0.15λ _ {high}, where the λ _{low} and the λ _{high} are the beginning and the end of the working frequency. By combining this metasurface-based MA with the dendritic-resistance-film-based microwave metasurface absorber (MMA), we designed a broadband MMA. The simulations and experiments showed that this kind of MMA can absorb the radiation effectively at a wide frequency range 4.5-17.5 GHz. And the thickness of this combined MMA is 4 mm. All the structures showed their insensitivity to the incident angle (0°-40°) and the polarization of the incident wave because of their structural symmetry. In addition, the small thickness, low apparent density, and flexibility made those structures possess the advantages of being applied in microwave stealth and radar cross-section (RCS) reduction.

  16. Spinal cord injury, dendritic spine remodeling, and spinal memory mechanisms.

    Science.gov (United States)

    Tan, Andrew M; Waxman, Stephen G

    2012-05-01

    Spinal cord injury (SCI) often results in the development of neuropathic pain, which can persist for months and years after injury. Although many aberrant changes to sensory processing contribute to the development of chronic pain, emerging evidence demonstrates that mechanisms similar to those underlying classical learning and memory can contribute to central sensitization, a phenomenon of amplified responsiveness to stimuli in nociceptive dorsal horn neurons. Notably, dendritic spines have emerged as major players in learning and memory, providing a structural substrate for how the nervous system modifies connections to form and store information. Until now, most information regarding dendritic spines has been obtained from studies in the brain. Recent experimental data in the spinal cord, however, demonstrate that Rac1-regulated dendritic spine remodeling occurs on second-order wide dynamic range neurons and accompanies neuropathic pain after SCI. Thus, SCI-induced synaptic potentiation engages a putative spinal memory mechanism. A compelling, novel possibility for pain research is that a synaptic model of long-term memory storage could explain the persistent nature of neuropathic pain. Such a conceptual bridge between pain and memory could guide the development of more effective strategies for treatment of chronic pain after injury to the nervous system. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Sarcomeres pattern proprioceptive sensory dendritic endings through Perlecan/UNC-52 in C. elegans

    Science.gov (United States)

    Liang, Xing; Dong, Xintong; Moerman, Donald G.; Shen, Kang; Wang, Xiangming

    2015-01-01

    Sensory dendrites innervate peripheral tissues through cell-cell interactions that are poorly understood. The proprioceptive neuron PVD in C. elegans extends regular terminal dendritic branches between muscle and hypodermis. We found that the PVD branch pattern was instructed by adhesion molecule SAX-7/L1CAM, which formed regularly spaced stripes on the hypodermal cell. The regularity of the SAX-7 pattern originated from the repeated and regularly spaced dense body of the sarcomeres in the muscle. The extracellular proteoglycan, UNC-52/Perlecan, links the dense body to the hemidesmosome on the hypodermal cells, which in turn instructed the SAX-7 stripes and PVD dendrites. Both UNC-52 and hemidesmosome components exhibited highly regular stripes that interdigitated with the SAX-7 stripe and PVD dendrites, reflecting the striking precision of subcellular patterning between muscle, hypodermis and dendrites. Hence, the muscular contractile apparatus provides the instructive cues to pattern proprioceptive dendrites. PMID:25982673

  18. Acute paretic syndrome in juvenile White Leghorn chickens resembles late stages of acute inflammatory demyelinating polyneuropathies in humans

    Directory of Open Access Journals (Sweden)

    Preisinger Rudolf

    2010-01-01

    Full Text Available Abstract Background Sudden limb paresis is a common problem in White Leghorn flocks, affecting about 1% of the chicken population before achievement of sexual maturity. Previously, a similar clinical syndrome has been reported as being caused by inflammatory demyelination of peripheral nerve fibres. Here, we investigated in detail the immunopathology of this paretic syndrome and its possible resemblance to human neuropathies. Methods Neurologically affected chickens and control animals from one single flock underwent clinical and neuropathological examination. Peripheral nervous system (PNS alterations were characterised using standard morphological techniques, including nerve fibre teasing and transmission electron microscopy. Infiltrating cells were phenotyped immunohistologically and quantified by flow cytometry. The cytokine expression pattern was assessed by quantitative real-time PCR (qRT-PCR. These investigations were accomplished by MHC genotyping and a PCR screen for Marek's disease virus (MDV. Results Spontaneous paresis of White Leghorns is caused by cell-mediated, inflammatory demyelination affecting multiple cranial and spinal nerves and nerve roots with a proximodistal tapering. Clinical manifestation coincides with the employment of humoral immune mechanisms, enrolling plasma cell recruitment, deposition of myelin-bound IgG and antibody-dependent macrophageal myelin-stripping. Disease development was significantly linked to a 539 bp microsatellite in MHC locus LEI0258. An aetiological role for MDV was excluded. Conclusions The paretic phase of avian inflammatory demyelinating polyradiculoneuritis immunobiologically resembles the late-acute disease stages of human acute inflammatory demyelinating polyneuropathy, and is characterised by a Th1-to-Th2 shift.

  19. Dendritic cells loaded with HeLa-derived exosomes simulate an antitumor immune response.

    Science.gov (United States)

    Ren, Guoping; Wang, Yanhong; Yuan, Shexia; Wang, Baolian

    2018-05-01

    The aim of the present study was to investigate the effect of loading dendritic cells (DCs) with HeLa-derived exosomes on cytotoxic T-lymphocyte (CTL) responses, and the cytotoxic effects of CTL responses on the HeLa cell line. Ultrafiltration centrifugation combined with sucrose density gradient ultracentrifugation was applied to isolate exosomes (HeLa-exo) from the supernatant of HeLa cells. Morphological features of HeLa-exo were identified by transmission electron microscopy (TEM), and the expression of cluster of differentiation (CD)63 was detected by western blotting. Next, monocytes were isolated from peripheral blood and cultured with the removal of adherent cells to induce DC proliferation. DCs were then phenotypically characterized by flow cytometry. Finally, MTT assays were performed to analyze the effects of DCs loaded with HeLa-exo on T cell proliferation and cytotoxicity assays to evaluate the effect of CTL responses on HeLa cells. TEM revealed that HeLa-exo exhibit typical cup-shaped morphology with a diameter range of 30-100 nm. It was also identified that the CD63 surface antigen is expressed on HeLa-exo. Furthermore, monocyte-derived DCs were able to express CD1a, suggesting that DC induction was a success. DCs exhibited hair-like protrusions and other typical dendritic cell morphology. Furthermore, DCs loaded with HeLa-exo could enhance CTL proliferation and the cytotoxic activity of CTLs compared with DCs without HeLa-exo (PHeLa-exo may promote T cell proliferation and induce CTL responses to inhibit the growth of cervical cancer cells in vitro .

  20. Leishmanicidal activity of synthetic antimicrobial peptides in an infection model with human dendritic cells.

    Science.gov (United States)

    Pérez-Cordero, José Julián; Lozano, José Manuel; Cortés, Jimena; Delgado, Gabriela

    2011-04-01

    Different species of Leishmania are responsible for cutaneous, mucocutaneous or visceral leishmaniasis infections in millions of people around the world [14]. The adverse reactions caused by antileishmanial drugs, emergence of resistance and lack of a vaccine have motivated the search for new therapeutic options to control this disease. Different sources of antimicrobial molecules are under study as antileishmanial agents, including peptides with antimicrobial and/or immunomodulatory activity, which have been considered to be potentially active against diverse species of Leishmania[7,39]. This study evaluated the cytotoxicity on dendritic cells, hemolytic activity, leishmanicidal properties on Leishmania panamensis and Leishmania major promastigotes and effectiveness on parasite intracellular forms (dendritic cells infected with L. panamensis and L. major promastigotes), when each parasite in culture was exposed to different concentrations of a group of synthetic peptides with previously reported antimicrobial properties, which were synthesized based on their naturally occurring reported sequences. Dermaseptin, Pr-2 and Pr-3 showed inhibitory activity on the growth of L. panamensis promastigotes, while Andropin and Cecropin A (with a selectivity index of 4 and 40, respectively) showed specific activity against intracellular forms of this species. The activities of Andropin and Cecropin A were exclusively against the intracellular forms of the parasite, therefore indicating the relevance of these two peptides as potential antileishmanial agents. In the case of L. major promastigotes, Melittin and Dermaseptin showed inhibitory activity, the latter also showed a selectivity index of 8 against intracellular forms. These findings suggest Andropin, Cecropin A and Dermaseptin as potential therapeutic tools to treat New and Old World cutaneous leishmaniasis. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Selective dendritic susceptibility to bioenergetic, excitotoxic and redox perturbations in cortical neurons.

    Science.gov (United States)

    Hasel, Philip; Mckay, Sean; Qiu, Jing; Hardingham, Giles E

    2015-09-01

    Neurodegenerative and neurological disorders are often characterised by pathological changes to dendrites, in advance of neuronal death. Oxidative stress, energy deficits and excitotoxicity are implicated in many such disorders, suggesting a potential vulnerability of dendrites to these situations. Here we have studied dendritic vs. somatic responses of primary cortical neurons to these types of challenges in real-time. Using a genetically encoded indicator of intracellular redox potential (Grx1-roGFP2) we found that, compared to the soma, dendritic regions exhibited more dramatic fluctuations in redox potential in response to sub-lethal ROS exposure, and existed in a basally more oxidised state. We also studied the responses of dendritic and somatic regions to excitotoxic NMDA receptor activity. Both dendritic and somatic regions experienced similar increases in cytoplasmic Ca²⁺. Interestingly, while mitochondrial Ca²⁺ uptake and initial mitochondrial depolarisation were similar in both regions, secondary delayed mitochondrial depolarisation was far weaker in dendrites, potentially as a result of less NADH depletion. Despite this, ATP levels were found to fall faster in dendritic regions. Finally we studied the responses of dendritic and somatic regions to energetically demanding action potential burst activity. Burst activity triggered PDH dephosphorylation, increases in oxygen consumption and cellular NADH:NAD ratio. Compared to somatic regions, dendritic regions exhibited a smaller degree of mitochondrial Ca²⁺ uptake, lower fold-induction of NADH and larger reduction in ATP levels. Collectively, these data reveal that dendritic regions of primary neurons are vulnerable to greater energetic and redox fluctuations than the cell body, which may contribute to disease-associated dendritic damage. This article is part of a Special Issue entitled: 13th European Symposium on Calcium. Copyright © 2014. Published by Elsevier B.V.

  2. Active action potential propagation but not initiation in thalamic interneuron dendrites

    Science.gov (United States)

    Casale, Amanda E.; McCormick, David A.

    2012-01-01

    Inhibitory interneurons of the dorsal lateral geniculate nucleus of the thalamus modulate the activity of thalamocortical cells in response to excitatory input through the release of inhibitory neurotransmitter from both axons and dendrites. The exact mechanisms by which release can occur from dendrites are, however, not well understood. Recent experiments using calcium imaging have suggested that Na/K based action potentials can evoke calcium transients in dendrites via local active conductances, making the back-propagating action potential a candidate for dendritic neurotransmitter release. In this study, we employed high temporal and spatial resolution voltage-sensitive dye imaging to assess the characteristics of dendritic voltage deflections in response to Na/K action potentials in interneurons of the mouse dorsal lateral geniculate nucleus. We found that trains or single action potentials elicited by somatic current injection or local synaptic stimulation led to action potentials that rapidly and actively back-propagated throughout the entire dendritic arbor and into the fine filiform dendritic appendages known to release GABAergic vesicles. Action potentials always appeared first in the soma or proximal dendrite in response to somatic current injection or local synaptic stimulation, and the rapid back-propagation into the dendritic arbor depended upon voltage-gated sodium and TEA-sensitive potassium channels. Our results indicate that thalamic interneuron dendrites integrate synaptic inputs that initiate action potentials, most likely in the axon initial segment, that then back-propagate with high-fidelity into the dendrites, resulting in a nearly synchronous release of GABA from both axonal and dendritic compartments. PMID:22171033

  3. The role of dendritic non-linearities in single neuron computation

    Directory of Open Access Journals (Sweden)

    Boris Gutkin

    2014-05-01

    Full Text Available Experiment has demonstrated that summation of excitatory post-synaptic protientials (EPSPs in dendrites is non-linear. The sum of multiple EPSPs can be larger than their arithmetic sum, a superlinear summation due to the opening of voltage-gated channels and similar to somatic spiking. The so-called dendritic spike. The sum of multiple of EPSPs can also be smaller than their arithmetic sum, because the synaptic current necessarily saturates at some point. While these observations are well-explained by biophysical models the impact of dendritic spikes on computation remains a matter of debate. One reason is that dendritic spikes may fail to make the neuron spike; similarly, dendritic saturations are sometime presented as a glitch which should be corrected by dendritic spikes. We will provide solid arguments against this claim and show that dendritic saturations as well as dendritic spikes enhance single neuron computation, even when they cannot directly make the neuron fire. To explore the computational impact of dendritic spikes and saturations, we are using a binary neuron model in conjunction with Boolean algebra. We demonstrate using these tools that a single dendritic non-linearity, either spiking or saturating, combined with somatic non-linearity, enables a neuron to compute linearly non-separable Boolean functions (lnBfs. These functions are impossible to compute when summation is linear and the exclusive OR is a famous example of lnBfs. Importantly, the implementation of these functions does not require the dendritic non-linearity to make the neuron spike. Next, We show that reduced and realistic biophysical models of the neuron are capable of computing lnBfs. Within these models and contrary to the binary model, the dendritic and somatic non-linearity are tightly coupled. Yet we show that these neuron models are capable of linearly non-separable computations.

  4. Ultrafast Photoresponsive Starburst and Dendritic Fullerenyl Nanostructures for Broadband Nonlinear Photonic Material Applications

    Science.gov (United States)

    2014-08-20

    AFRL-OSR-VA-TR-2014-0197 ULTRAFAST PHOTORESPONSIVE STARBURST AND DENDRITIC FULLERENYL NOSTRUCTURES FOR BROADBAND NONLINEAR PHOTONIC MATERIAL...Report 3. DATES COVERED (From - To) 03-01-2009 – 05-31-2014 4. TITLE AND SUBTITLE Ultrafast Photoresponsive Starburst and Dendritic Fullerenyl...photophysical properties of ultrafast photoresponsive starburst and dendritic C60/C70-light harvesting antenna-based organic nanostructures for broadband

  5. Contextual Learning Induces Dendritic Spine Clustering in Retrosplenial Cortex

    Directory of Open Access Journals (Sweden)

    Adam C Frank

    2014-03-01

    Full Text Available Molecular and electrophysiological studies find convergent evidence suggesting that plasticity within a dendritic tree is not randomly dispersed, but rather clustered into functional groups. Further, results from in silico neuronal modeling show that clustered plasticity is able to increase storage capacity 45 times compared to dispersed plasticity. Recent in vivo work utilizing chronic 2-photon microscopy tested the clustering hypothesis and showed that repetitive motor learning is able to induce clustered addition of new dendritic spines on apical dendrites of L5 neurons in primary motor cortex; moreover, clustered spines were found to be more stable than non-clustered spines, suggesting a physiological role for spine clustering. To further test this hypothesis we used in vivo 2-photon imaging in Thy1-YFP-H mice to chronically examine dendritic spine dynamics in retrosplenial cortex (RSC during spatial learning. RSC is a key component of an extended spatial learning and memory circuit that includes hippocampus and entorhinal cortex. Importantly, RSC is known from both lesion and immediate early gene studies to be critically involved in spatial learning and more specifically in contextual fear conditioning. We utilized a modified contextual fear conditioning protocol wherein animals received a mild foot shock each day for five days; this protocol induces gradual increases in context freezing over several days before the animals reach a behavioral plateau. We coupled behavioral training with four separate in vivo imaging sessions, two before training begins, one early in training, and a final session after training is complete. This allowed us to image spine dynamics before training as well as early in learning and after animals had reached behavioral asymptote. We find that this contextual learning protocol induces a statistically significant increase in the formation of clusters of new dendritic spines in trained animals when compared to home

  6. Nonlinear dendritic integration in CA1 pyramidal neurons during locomotion.

    Directory of Open Access Journals (Sweden)

    Jeff Magee

    2014-04-01

    Full Text Available Most neuronal circuits receive at least two functionally distinct input types (intrinsic vs. extrinsic; sensory vs. motor; etc. In many pyramidal neuron based microcircuits integration of these two input signals can proceed nonlinearly through the production of active dendritic voltage signals. For example, appropriately timed, perisomatically located, hippocampal (SC and distal dendrite targeting entorhinal (EC3 input produces a distal dendritic Ca2+ plateau potential that drives burst firing output from CA1 pyramidal neurons in vitro. Related signals have been observed in neocortical pyramidal neurons. Until recently it was unknown whether these events occurred in vivo and, if so, during what behavioral states. Here we used simultaneous whole-cell patch and field potential recordings in head-fixed mice running on a linear track treadmill to study this dendritic plateau driven burst firing (plateaus in CA1 neurons. We find that during locomotion dendritic plateau potentials occur within the neuron’s place field with initiation probability peaking near the peak of the firing field. Plateaus produce a large (32±4mV; n=12, slow (duration; 51±7ms somatic depolarization that appears similar to that measured in vitro. Interestingly, plateaus exhibit a dramatic level of theta-phase modulation (~97% that peaks late in the theta cycle (~330°. This late phase peak in plateau potential initiation is near the theta-phase preference of EC3 inputs, suggesting a theta-phase dependent interaction of SC and EC3 inputs. We tested this idea by manipulating the phase of SC inputs by injecting phase adjusted theta frequency currents into CA1 somas. Biasing AP firing earlier in the theta phase decreased plateau probability to ~48% of control whereas biasing AP firing later in phase increased plateau probability 276%. We next directly examined the role of EC3 inputs by inactivating the EC3 axons in CA1 via local light activation of axons expressing

  7. Dendritic Cell-Based Immunotherapy of Breast Cancer: Modulation by CpG

    National Research Council Canada - National Science Library

    Baar, Joseph

    2004-01-01

    ... in the United States in 2004. Thus, patients with MBC who fail conventional therapies are candidates for clinical trials using novel therapeutic approaches, including immunotherapy. Dendritic cells (DC...

  8. Conserved RNA-Binding Proteins Required for Dendrite Morphogenesis in Caenorhabditis elegans Sensory Neurons

    Science.gov (United States)

    Antonacci, Simona; Forand, Daniel; Wolf, Margaret; Tyus, Courtney; Barney, Julia; Kellogg, Leah; Simon, Margo A.; Kerr, Genevieve; Wells, Kristen L.; Younes, Serena; Mortimer, Nathan T.; Olesnicky, Eugenia C.; Killian, Darrell J.

    2015-01-01

    The regulation of dendritic branching is critical for sensory reception, cell−cell communication within the nervous system, learning, memory, and behavior. Defects in dendrite morphology are associated with several neurologic disorders; thus, an understanding of the molecular mechanisms that govern dendrite morphogenesis is important. Recent investigations of dendrite morphogenesis have highlighted the importance of gene regulation at the posttranscriptional level. Because RNA-binding proteins mediate many posttranscriptional mechanisms, we decided to investigate the extent to which conserved RNA-binding proteins contribute to dendrite morphogenesis across phyla. Here we identify a core set of RNA-binding proteins that are important for dendrite morphogenesis in the PVD multidendritic sensory neuron in Caenorhabditis elegans. Homologs of each of these genes were previously identified as important in the Drosophila melanogaster dendritic arborization sensory neurons. Our results suggest that RNA processing, mRNA localization, mRNA stability, and translational control are all important mechanisms that contribute to dendrite morphogenesis, and we present a conserved set of RNA-binding proteins that regulate these processes in diverse animal species. Furthermore, homologs of these genes are expressed in the human brain, suggesting that these RNA-binding proteins are candidate regulators of dendrite development in humans. PMID:25673135

  9. Grain growth and thermal stability accompanying recrystallization in undercooled Ni-3at.%Sn alloy

    International Nuclear Information System (INIS)

    Chen, Z.; Chen, Q.; Shen, C.J.; Liu, F.

    2015-01-01

    The grain growth and thermal stability after recrystallization in as-solidified highly undercooled Ni-3at.%Sn alloy melt were investigated. As for undercooled Ni-3at.%Sn alloy, a transition from dendritic to granular crystals occurred when ΔT≥ΔT * , which was induced by the plastic deformation of dendrites and subsequent recrystallization. On this basis, the subsequent grain growth and solute segregation accompanying recalescence were calculated by a recently proposed thermo-kinetic model, which showed close agreement with the experimental results. It is concluded that the grain growth process was interrelated to recalescence, solute trapping and solute segregation of Sn atoms captured by solute trapping, which was responsible for the reduction of grain boundary energy and improvement of thermal stability. - Highlights: • A transition from dendritic to granular crystals occurred when ΔT≥ΔT * . • The grain growth accompanying recalescence was calculated. • A close agreement with the experimental results was shown

  10. A cell adhesion molecule mimetic, FGL peptide, induces alterations in synapse and dendritic spine structure in the dentate gyrus of aged rats: a three-dimensional ultrastructural study

    DEFF Research Database (Denmark)

    Popov, Victor I; Medvedev, Nikolay I; Kraev, Igor V

    2008-01-01

    The FGL peptide is a neural cell adhesion molecule (NCAM) mimetic comprising a 15-amino-acid-long sequence of the FG loop region of the second fibronectin type III module of NCAM. It corresponds to the binding site of NCAM for the fibroblast growth factor receptor 1. FGL improves cognitive function...... through enhancement of synaptic function. We examined the effect of FGL on synaptic and dendritic structure in the brains of aged (22-month-old) rats that were injected subcutaneously (8 mg/kg) at 2-day intervals until 19 days after the start of the experiment. Animals were perfused with fixative, brains...... structure of synapses and dendritic spines in hippocampus of aged rats, complementing data showing its effect on cognitive processes....

  11. Molecular signatures of maturing dendritic cells: implications for testing the quality of dendritic cell therapies

    Directory of Open Access Journals (Sweden)

    Wang Ena

    2010-01-01

    Full Text Available Abstract Background Dendritic cells (DCs are often produced by granulocyte-macrophage colony-stimulating factor (GM-CSF and interleukin-4 (IL-4 stimulation of monocytes. To improve the effectiveness of DC adoptive immune cancer therapy, many different agents have been used to mature DCs. We analyzed the kinetics of DC maturation by lipopolysaccharide (LPS and interferon-γ (IFN-γ induction in order to characterize the usefulness of mature DCs (mDCs for immune therapy and to identify biomarkers for assessing the quality of mDCs. Methods Peripheral blood mononuclear cells were collected from 6 healthy subjects by apheresis, monocytes were isolated by elutriation, and immature DCs (iDCs were produced by 3 days of culture with GM-CSF and IL-4. The iDCs were sampled after 4, 8 and 24 hours in culture with LPS and IFN-γ and were then assessed by flow cytometry, ELISA, and global gene and microRNA (miRNA expression analysis. Results After 24 hours of LPS and IFN-γ stimulation, DC surface expression of CD80, CD83, CD86, and HLA Class II antigens were up-regulated. Th1 attractant genes such as CXCL9, CXCL10, CXCL11 and CCL5 were up-regulated during maturation but not Treg attractants such as CCL22 and CXCL12. The expression of classical mDC biomarker genes CD83, CCR7, CCL5, CCL8, SOD2, MT2A, OASL, GBP1 and HES4 were up-regulated throughout maturation while MTIB, MTIE, MTIG, MTIH, GADD45A and LAMP3 were only up-regulated late in maturation. The expression of miR-155 was up-regulated 8-fold in mDCs. Conclusion DCs, matured with LPS and IFN-γ, were characterized by increased levels of Th1 attractants as opposed to Treg attractants and may be particularly effective for adoptive immune cancer therapy.

  12. GM-CSF Monocyte-Derived Cells and Langerhans Cells As Part of the Dendritic Cell Family

    Directory of Open Access Journals (Sweden)

    Manfred B. Lutz

    2017-10-01

    Full Text Available Dendritic cells (DCs and macrophages (Mph share many characteristics as components of the innate immune system. The criteria to classify the multitude of subsets within the mononuclear phagocyte system are currently phenotype, ontogeny, transcription patterns, epigenetic adaptations, and function. More recently, ontogenetic, transcriptional, and proteomic research approaches uncovered major developmental differences between Flt3L-dependent conventional DCs as compared with Mphs and monocyte-derived DCs (MoDCs, the latter mainly generated in vitro from murine bone marrow-derived DCs (BM-DCs or human CD14+ peripheral blood monocytes. Conversely, in vitro GM-CSF-dependent monocyte-derived Mphs largely resemble MoDCs whereas tissue-resident Mphs show a common embryonic origin from yolk sac and fetal liver with Langerhans cells (LCs. The novel ontogenetic findings opened discussions on the terminology of DCs versus Mphs. Here, we bring forward arguments to facilitate definitions of BM-DCs, MoDCs, and LCs. We propose a group model of terminology for all DC subsets that attempts to encompass both ontogeny and function.

  13. Guinea-pig interpubic joint (symphysis pubica relaxation at parturition: Underlying cellular processes that resemble an inflammatory response

    Directory of Open Access Journals (Sweden)

    Muñoz-de-Toro Mónica

    2003-11-01

    Full Text Available Abstract Background At term, cervical ripening in coordination with uterine contractions becomes a prerequisite for a normal vaginal delivery. Currently, cervical ripening is considered to occur independently from uterine contractions. Many evidences suggest that cervical ripening resembles an inflammatory process. Comparatively little attention has been paid to the increased flexibility of the pelvic symphysis that occurs in many species to enable safe delivery. The aim of this study was to investigate whether the guinea-pig interpubic joint relaxation process observed during late pregnancy and parturition resembles an inflammatory process. Methods Samples of pubic symphysis were taken from pregnant guinea-pigs sacrificed along gestation, parturition and postpartum. Serial sections of paraffin-embedded tissues were used to measure the interpubic distance on digitalized images, stained with Giemsa to quantify leukocyte infiltration and to describe the vascular area changes, or studied by the picrosirius-polarization method to evaluate collagen remodeling. P4 and E2 serum levels were measured by a sequential immunometric assay. Results Data showed that the pubic relaxation is associated with an increase in collagen remodeling. In addition, a positive correlation between E2 serum levels and the increase in the interpubic distance was found. On the other hand, a leukocyte infiltration in the interpubic tissue around parturition was described, with the presence of almost all inflammatory cells types. At the same time, histological images show an increase in vascular area (angiogenesis. Eosinophils reached their highest level immediately before parturition; whereas for the neutrophilic and mononuclear infiltration higher values were recorded one day after parturition. Correlation analysis showed that eosinophils and mononuclear cells were positively correlated with E2 levels, but only eosinophilic infiltration was associated with collagen remodeling

  14. Dendritic multiporphyrin arrays as light-harvesting antennae: effects of generation number and morphology on intramolecular energy transfer.

    Science.gov (United States)

    Choi, Myung-Seok; Aida, Takuzo; Yamazaki, Tomoko; Yamazaki, Iwao

    2002-06-17

    A series of star- and cone-shaped dendritic multiporphyrin arrays, (nPZn)4PFB and (nPZn)1PFB, respectively, that contain energy-donating dendritic zinc porphyrin (PZn) wedges of different numbers (n = 1, 3, and 7) of the PZn units, attached to an energy-accepting free-base porphyrin (PFB) core, were synthesized by a convergent growth approach. For the cone-shaped series ((nPZn)1PFB), the efficiency of energy transfer (phi ENT) from the photoexcited PZn units to the focal PFB core, as evaluated from the fluorescence lifetimes of the PZn units, considerably decreased as the generation number increased: (1PZn)1PFB (86%), (3PZn)1PFB (66%), and (7PZn)1PFB (19%). In sharp contrast, the star-shaped series ((nPZn)4PFB) all showed high phi ENT values: (1PZn)4PFB (87%), (3PZn)4PFB (80%), and (7PZn)4PFB (71%). Energy transfer efficiencies of (3PZn)4-ester-PFB, (1PZn)4-ester-PFB, and (3PZn)1-ester-PFB, whose dendritic PZn wedges are connected by an ester linkage to the PFB core, were almost comparable to those of the corresponding ether-linked versions. Fluorescence depolarization (P) studies showed much lower P values for star-shaped (7PZn)4PFB and (3PZn)4PFB than cone-shaped (7PZn)1PFB and (3PZn)1PFB, respectively, indicating a highly efficient energy migration among the PZn units in the star-shaped series. Such a morphology-assisted photochemical event is probably responsible for the excellent light-harvesting activity of large (7PZn)4PFB molecules.

  15. Family Resemblances: Human Reproductive Cloning as an Example for Reconsidering the Mutual Relationships between Bioethics and Science Fiction.

    Science.gov (United States)

    Hansen, Solveig L

    2018-03-08

    In the traditions of narrative ethics and casuistry, stories have a well-established role. Specifically, illness narratives provide insight into patients' perspectives and histories. However, because they tend to see fiction as an aesthetic endeavour, practitioners in these traditions often do not realize that fictional stories are valuable moral sources of their own. In this paper I employ two arguments to show the mutual relationship between bioethics and fiction, specifically, science fiction. First, both discourses use imagination to set a scene and determine a perspective. Second, bioethics and science fiction share the family resemblance of expressing moral beliefs. I then consider how understanding bioethics and science fiction as interrelated discourses can be the basis of a methodology for inquiry into relational autonomy in the context of biotechnologies and medicine. As an example of this methodology, I analyse Fay Weldon's novel The Cloning of Joanna May (1989).

  16. 'Hair-on-end' skull changes resembling thalassemia caused by marrow expansion in uncorrected complex cyanotic heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Walor, David M.; Berdon, Walter E. [Columbia University Medical Center, Department of Radiology Children' s Hospital of New York, New York, NY (United States); Westra, Sjirk J. [Massachusetts General Hospital, Department of Radiology, Boston, MA (United States)

    2005-07-01

    ''Hair-on-end'' skull changes resembling thalassemia were rarely described in the 1950s and 1960s in children with cyanotic congenital heart diseases; these changes were described almost entirely in patients with tetralogy of Fallot or D-transposition of the great arteries. As these lesions have become correctable, the osseous changes, never common, seem now only to exist in a small number of patients with uncorrectable complex cyanotic congenital heart disease who survive in a chronic hypoxic state. We present two cases: a case of marked marrow expansion in the skull of a 5-year-old boy with uncorrectable cyanotic heart disease studied by CT, and a second case of an 8-year-old with tetralogy of Fallot and pulmonary atresia studied by plain skull radiographs. The true incidence of these findings is unknown. (orig.)

  17. 'Hair-on-end' skull changes resembling thalassemia caused by marrow expansion in uncorrected complex cyanotic heart disease

    International Nuclear Information System (INIS)

    Walor, David M.; Berdon, Walter E.; Westra, Sjirk J.

    2005-01-01

    ''Hair-on-end'' skull changes resembling thalassemia were rarely described in the 1950s and 1960s in children with cyanotic congenital heart diseases; these changes were described almost entirely in patients with tetralogy of Fallot or D-transposition of the great arteries. As these lesions have become correctable, the osseous changes, never common, seem now only to exist in a small number of patients with uncorrectable complex cyanotic congenital heart disease who survive in a chronic hypoxic state. We present two cases: a case of marked marrow expansion in the skull of a 5-year-old boy with uncorrectable cyanotic heart disease studied by CT, and a second case of an 8-year-old with tetralogy of Fallot and pulmonary atresia studied by plain skull radiographs. The true incidence of these findings is unknown. (orig.)

  18. An analysis on equal width quantization and linearly separable subcode encoding-based discretization and its performance resemblances

    Directory of Open Access Journals (Sweden)

    Lim Meng-Hui

    2011-01-01

    Full Text Available Abstract Biometric discretization extracts a binary string from a set of real-valued features per user. This representative string can be used as a cryptographic key in many security applications upon error correction. Discretization performance should not degrade from the actual continuous features-based classification performance significantly. However, numerous discretization approaches based on ineffective encoding schemes have been put forward. Therefore, the correlation between such discretization and classification has never been made clear. In this article, we aim to bridge the gap between continuous and Hamming domains, and provide a revelation upon how discretization based on equal-width quantization and linearly separable subcode encoding could affect the classification performance in the Hamming domain. We further illustrate how such discretization can be applied in order to obtain a highly resembled classification performance under the general Lp distance and the inner product metrics. Finally, empirical studies conducted on two benchmark face datasets vindicate our analysis results.

  19. Lynch Syndrome Associated Colon Adenocarcinoma Resembling Lymphoma on Fluoro-Deoxyglucose-Positron Emission Tomography/Computed Tomography

    International Nuclear Information System (INIS)

    Aparici, Carina Mari; Win, Aung Zaw

    2015-01-01

    The patient was a 46-year-old Asian male diagnosed with lynch syndrome associated colon adenocarcinoma in the right ascending colon. A presurgical staging 18-fluoro-deoxyglucose-positron emission tomography/computed tomography (FDG-PET/CT) found increased metabolic activity in the cervical, axillary, mediastinal, supraclavicular, para-aortic and mesenteric lymph nodes. This pattern of metastasis was very unusual for lynch syndrome associated colon adenocarcinoma and the involvement of those lymph nodes resembles the pattern of spread of lymphoma. He underwent right hemicolectomy and he was subsequently treated with 12 cycles of folinic acid (leucovorin), fluorouracil (5-FU), irinotecan. A restaging FDG-PET/CT at the end of the chemotherapy showed interval decrease in size and metabolic activity in the affected lymph nodes. FDG-PET/CT is a useful imaging modality in following-up the treatment response in colon adenocarcinoma

  20. Meningiomas with conventional MRI findings resembling intraaxial tumors: can perfusion-weighted MRI be helpful in differentiation?

    Energy Technology Data Exchange (ETDEWEB)

    Hakyemez, Bahattin [Uludag University Medical School, Department of Radiology, Bursa (Turkey); Bursa State Hospital, Department of Radiology, Bursa (Turkey); Yildirim, Nalan; Erdogan, Cueneyt; Parlak, Mufit [Uludag University Medical School, Department of Radiology, Bursa (Turkey); Kocaeli, Hasan; Korfali, Ender [Uludag University Medical School, Department of Neurosurgery, Bursa (Turkey)

    2006-10-15

    To investigate the contribution of perfusion-weighted MRI to the differentiation of meningiomas with atypical conventional MRI findings from intraaxial tumors. We retrospectively analyzed 54 meningiomas, 12 glioblastomas and 13 solitary metastases. We detected 6 meningiomas with atypical features on conventional MRI resembling intraaxial tumors. The regional cerebral blood flow (rCBV) ratios of all tumors were calculated via perfusion-weighted MRI. The signal intensity-time curves were plotted and three different curve patterns were observed. The type 1 curve resembled normal brain parenchyma or the postenhancement part was minimally below the baseline, the type 2 curve was similar to the type 1 curve but with the postenhancement part above the baseline, and the type 3 curve had the postenhancement part below the baseline accompanied by widening of the curve. Student's t-test was used for statistical analysis. On CBV images meningiomas were hypervascular and the mean rCBV ratio was 10.58{+-}2.00. For glioblastomas and metastatic lesions, the rCBV ratios were 5.02{+-}1.40 and 4.68{+-}1.54, respectively. There was a statistically significant difference in rCBV ratios between meningiomas and glioblastomas and metastases (P<0.001). Only one of the meningiomas displayed a type 2 curve while five showed a type 3 curve. Glioblastomas and metastases displayed either a type 1 or a type 2 curve. None of the meningiomas showed a type 1 curve and none of the glioblastomas or metastases showed a type 3 curve. (orig.)

  1. Pathogenesis of Candida albicans infections in the alternative chorio-allantoic membrane chicken embryo model resembles systemic murine infections.

    Directory of Open Access Journals (Sweden)

    Ilse D Jacobsen

    Full Text Available Alternative models of microbial infections are increasingly used to screen virulence determinants of pathogens. In this study, we investigated the pathogenesis of Candida albicans and C. glabrata infections in chicken embryos infected via the chorio-allantoic membrane (CAM and analyzed the virulence of deletion mutants. The developing immune system of the host significantly influenced susceptibility: With increasing age, embryos became more resistant and mounted a more balanced immune response, characterized by lower induction of proinflammatory cytokines and increased transcription of regulatory cytokines, suggesting that immunopathology contributes to pathogenesis. While many aspects of the chicken embryo response resembled murine infections, we also observed significant differences: In contrast to systemic infections in mice, IL-10 had a beneficial effect in chicken embryos. IL-22 and IL-17A were only upregulated after the peak mortality in the chicken embryo model occurred; thus, the role of the Th17 response in this model remains unclear. Abscess formation occurs frequently in murine models, whereas the avian response was dominated by granuloma formation. Pathogenicity of the majority of 15 tested C. albicans deletion strains was comparable to the virulence in mouse models and reduced virulence was associated with significantly lower transcription of proinflammatory cytokines. However, fungal burden did not correlate with virulence and for few mutants like bcr1Δ and tec1Δ different outcomes in survival compared to murine infections were observed. C. albicans strains locked in the yeast stage disseminated significantly more often from the CAM into the embryo, supporting the hypothesis that the yeast morphology is responsible for dissemination in systemic infections. These data suggest that the pathogenesis of C. albicans infections in the chicken embryo model resembles systemic murine infections but also differs in some aspects. Despite

  2. Dendritic compartmentalization of chloride cotransporters underlies directional responses of starburst amacrine cells in retina.

    Science.gov (United States)

    Gavrikov, Konstantin E; Nilson, James E; Dmitriev, Andrey V; Zucker, Charles L; Mangel, Stuart C

    2006-12-05

    The mechanisms in the retina that generate light responses selective for the direction of image motion remain unresolved. Recent evidence indicates that directionally selective light responses occur first in the retina in the dendrites of an interneuron, i.e., the starburst amacrine cell, and that these responses are highly sensitive to the activity of Na-K-2Cl (NKCC) and K-Cl (KCC), two types of chloride cotransporter that determine whether the neurotransmitter GABA depolarizes or hyperpolarizes neurons, respectively. We show here that selective blockade of the NKCC2 and KCC2 cotransporters located on starburst dendrites consistently hyperpolarized and depolarized the starburst cells, respectively, and greatly reduced or eliminated their directionally selective light responses. By mapping NKCC2 and KCC2 antibody staining on these dendrites, we further show that NKCC2 and KCC2 are preferentially located in the proximal and distal dendritic compartments, respectively. Finally, measurements of the GABA reversal potential in different starburst dendritic compartments indicate that the GABA reversal potential at the distal dendrite is more hyperpolarized than at the proximal dendrite due to KCC2 activity. These results thus demonstrate that the differential distribution of NKCC2 on the proximal dendrites and KCC2 on the distal dendrites of starburst cells results in a GABA-evoked depolarization and hyperpolarization at the NKCC2 and KCC2 compartments, respectively, and underlies the directionally selective light responses of the dendrites. The functional compartmentalization of interneuron dendrites may be an important means by which the nervous system encodes complex information at the subcellular level.

  3. GABA(B) receptors inhibit backpropagating dendritic spikes in hippocampal CA1 pyramidal cells in vivo.

    Science.gov (United States)

    Leung, L Stan; Peloquin, Pascal

    2006-01-01

    Spike backpropagation has been proposed to enhance dendritic depolarization and synaptic plasticity. However, relatively little is known about the inhibitory control of spike backpropagation in vivo. In this study, the backpropagation of the antidromic spike into the dendrites of CA1 pyramidal cells was studied by extracellular recording in urethane-anesthetized rats. The population antidromic spike (pAS) in CA1 following stimulation of the alveus was recorded simultaneously with a 16-channel silicon probe and analyzed as current source density (CSD). The pAS current sink was shown to sequentially invade the soma and then the apical and basal dendrites. When the pAS was preceded sinks were reduced and delayed. Dendritic spike suppression was large after a high-intensity CA3 conditioning stimulus that evoked a population spike, small after a low-intensity CA3 conditioning stimulus, and weak after conditioning by another pAS. The late (150-400 ms latency) inhibition of the backpropagating pAS at the apical and basal dendrites was partially relieved by a GABA(B) receptor antagonist, CGP35348 or CGP56999A, given intracerebroventricularly (icv). CGP35348 icv also decreased the latency of the antidromic spike sinks at all depths. A compartment cable model of a CA1 pyramidal cell with excitable dendrites, combined with a model of extracellular potential generation, confirms that GABA(B) receptor activation delays a backpropagating spike and blocks distal dendritic spikes. GABA(B) receptor-mediated conductance increase and hyperpolarization, amplified by removing dendritic I(A) inactivation, contribute to conditioned dendritic spike suppression. In addition, the model shows that slow Na(+) channel inactivation also participates in conditioned spike suppression, which may partly explain the small dendritic spike suppression after conditioning with a weak orthodromic stimulus or another antidromic spike. Thus, both theory and experiment confirm an important role of the GABA

  4. A novel pseudopodial component of the dendritic cell anti-fungal response: the fungipod.

    Directory of Open Access Journals (Sweden)

    Aaron K Neumann

    2010-02-01

    Full Text Available Fungal pathologies are seen in immunocompromised and healthy humans. C-type lectins expressed on immature dendritic cells (DC recognize fungi. We report a novel dorsal pseudopodial protrusion, the "fungipod", formed by DC after contact with yeast cell walls. These structures have a convoluted cell-proximal end and a smooth distal end. They persist for hours, exhibit noticeable growth and total 13.7+/-5.6 microm long and 1.8+/-0.67 microm wide at the contact. Fungipods contain clathrin and an actin core surrounded by a sheath of cortactin. The actin cytoskeleton, but not microtubules, is required for fungipod integrity and growth. An apparent rearward flow (225+/-55 nm/second exists from the zymosan contact site into the distal fungipod. The phagocytic receptor Dectin-1 is not required for fungipod formation, but CD206 (Mannose Receptor is the generative receptor for these protrusions. The human pathogen Candida parapsilosis induces DC fungipod formation strongly, but the response is species specific since the related fungal pathogens Candida tropicalis and Candida albicans induce very few and no fungipods, respectively. Our findings show that fungipods are dynamic actin-driven cellular structures involved in fungal recognition by DC. They may promote yeast particle phagocytosis by DC and are a specific response to large (i.e., 5 microm particulate ligands. Our work also highlights the importance of this novel protrusive structure to innate immune recognition of medically significant Candida yeasts in a species specific fashion.

  5. Metronomic Chemotherapy Combined with Dendritic Cell Vaccine 
Inhibits VEGF Secretion

    Directory of Open Access Journals (Sweden)

    Yan ZHOU

    2013-09-01

    Full Text Available Background and objective The survival rate of lung cancer is low, thus new methods for treating this form of cancer must be explored. This study applies immune therapy with metronomic chemotherapy to observe the effect of combined therapy on suppressing tumor. Methods Mice were inoculated with Lewis lung carcinoma cells. Different treatments, namely, saline, metronomic chemotherapy, dendritic cell (DC vaccine, and metronomic chemotherapy with DC vaccine were administered to corresponding mice groups. Basic fibroblast growth factor and vascular endothelial growth factor (VEGF were detected via microdialysis and Luminex. Results The median survival time of mice in the metronomic chemotherapy with DC vaccine group was (27.6±3.2 days, whereas that in the saline group was (13.5±2.7 days (P=0.008, that in the DC vaccine group was (13.1±2.3 days (P=0.01, and that in the metronomic chemotherapy group was (11.8±3.0 days (P=0.01. The mice in the metronomic chemotherapy with DC vaccine group exhibited longer survival time than the mice in the other groups. This result could be related to the downregulation of VEGF secretion in the tumor-bearing mice groups within 48 h to 72 h. Conclusion VEGF secretion could be downregulated in tumor-bearing mice by administering metronomic chemotherapy with DC vaccine.

  6. Growth and study of barium oxalate single crystals in agar gel

    Indian Academy of Sciences (India)

    Unknown

    by X-ray powder diffractometry, infrared spectroscopy, thermogravimetric and differential thermal analysis. An attempt is ... Quality. Transparent, opaque. Opaque. Size. 17 × 4 × 2, 4 × 3 × 2 and 4 mm diameter 4 mm diameter. Figure 1. Dendritic growth of barium oxalate. interstitial and spherulitic growth well inside the gel on.

  7. Functional changes of dendritic cells in hypersensivity reactions to amoxicillin

    Directory of Open Access Journals (Sweden)

    C.M.F. Lima

    2010-10-01

    Full Text Available A better understanding of dendritic cell (DC involvement in responses to haptenic drugs is needed, because it represents a possible approach to the development of an in vitro test, which could identify patients prone to drug allergies. There are two main DC subsets: plasmacytoid DC (pDC and myeloid DC (mDC. β-lactams form hapten-carrier conjugates and may provide a suitable model to study DC behavior in drug allergy reactions. It has been demonstrated that drugs interact differently with DC in drug allergic and non-allergic patients, but there are no studies regarding these subsets. Our aim was to assess the functional changes of mDC and pDC harvested from an amoxicillin-hypersensitive 32-year-old woman who experienced a severe maculopapular exanthema as reflected in interleukin-6 (IL-6 production after stimulation with this drug and penicillin. We also aim to demonstrate, for the first time, the feasibility of this method for dendritic cell isolation followed by in vitro stimulation for studies of drug allergy physiopathology. DC were harvested using a double Percoll density gradient, which generates a basophil-depleted cell (BDC suspension. Further, pDC were isolated by blood DC antigen 4-positive magnetic selection and gravity filtration through magnetized columns. After stimulation with amoxicillin, penicillin and positive and negative controls, IL-6 production was measured by ELISA. A positive dose-response curve for IL-6 after stimulation with amoxicillin and penicillin was observed for pDC, but not for mDC or BDC suspension. These preliminary results demonstrate the feasibility of this methodology to expand the knowledge of the effect of dendritic cell activation by drug allergens.

  8. Dendritic cell immunotherapy for HIV infection: from theory to reality.

    Science.gov (United States)

    Oshiro, Telma Miyuki; de Almeida, Alexandre; da Silva Duarte, Alberto José

    2009-11-01

    Knowledge concerning the immunology of dendritic cells (DCs) accumulated over the last few decades and the development of methodologies to generate and manipulate these cells in vitro has made their therapeutic application a reality. Currently, clinical protocols for DC-based therapeutic vaccine in HIV-infected individuals show that it is a safe and promising approach. Concomitantly, important advances continue to be made in the development of methodologies to optimize DC acquisition, as well as the selection of safe, immunogenic HIV antigens and the evaluation of immune response in treated individuals.

  9. Targeting dendritic cells in vivo for cancer therapy

    Directory of Open Access Journals (Sweden)

    Irina eCaminschi

    2012-02-01

    Full Text Available Monoclonal antibodies that recognise cell surface molecules have been used deliver antigenic cargo to dendritic cells (DC for induction of immune responses. The encouraging anti-tumour immunity elicited using this immunisation strategy suggests its suitability for clinical trials. This review discusses the complex network of DC, the functional specialisation of DC-subsets, the immunological outcomes of targeting different DC-subsets and their cell surface receptors, and the requirements for the induction of effective anti-tumour immunity. Finally, we review preclinical experiments and the progress towards targeting human DC in vivo.

  10. Bone marrow dendritic cell-based anticancer vaccines

    Czech Academy of Sciences Publication Activity Database

    Indrová, Marie; Mendoza, Luis; Reiniš, Milan; Vonka, V.; Šmahel, M.; Němečková, Š.; Jandlová, Táňa; Bubeník, Jan

    2001-01-01

    Roč. 495, - (2001), s. 355-358 ISSN 0065-2598 R&D Projects: GA MZd NC5526; GA ČR GA312/98/0826; GA ČR GA312/99/0542; GA ČR GA301/00/0114; GA ČR GA301/01/0985; GA AV ČR IAA7052002 Institutional research plan: CEZ:AV0Z5052915 Keywords : HPV16 * dendritic cells * tumour vaccines Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 0.513, year: 2000

  11. Intracellular acidification by inhibition of the Na+/H+-exchanger leads to caspase-independent death of cerebellar granule neurons resembling paraptosis.

    Science.gov (United States)

    Schneider, D; Gerhardt, E; Bock, J; Müller, M M; Wolburg, H; Lang, F; Schulz, J B

    2004-07-01

    Potassium withdrawal is commonly used to induce caspase-mediated apoptosis in cerebellar granule neurons in vitro. However, the underlying and cell death-initiating mechanisms are unknown. We firstly investigated potassium efflux through the outward delayed rectifier K+ current (Ik) as a potential mediator. However, tetraethylammoniumchloride, an inhibitor of Ik, was ineffective to block apoptosis after potassium withdrawal. Since potassium withdrawal reduced intracellular pH (pHi) from 7.4 to 7.2, we secondly investigated the effects of intracellular acidosis. To study intracellular acidosis in cerebellar granule neurons, we inhibited the Na+/H+ exchanger (NHE) with 4-isopropyl-3-methylsulfonylbenzoyl-guanidine methanesulfonate (HOE 642) and 5-(N-ethyl-N-isopropyl)-amiloride. Both inhibitors concentration-dependently induced cell death and potentiated cell death after potassium withdrawal. Although inhibition of the NHE induced cell death with morphological criteria of apoptosis in light and electron microscopy including chromatin condensation, positive TUNEL staining and cell shrinkage, no internucleosomal DNA cleavage or activation of caspases was detected. In contrast to potassium withdrawal-induced apoptosis, cell death induced by intracellular acidification was not prevented by insulin-like growth factor-1, cyclo-adenosine-monophosphate, caspase inhibitors and transfection with an adenovirus expressing Bcl-XL. However, cycloheximide protected cerebellar granule neurons from death induced by potassium withdrawal as well as from death after treatment with HOE 642. Therefore, the molecular mechanisms leading to cell death after acidification appear to be different from the mechanisms after potassium withdrawal and resemble the biochemical but not the morphological characteristics of paraptosis.

  12. The relationship between dendritic branch dynamics and CPEB-labeled RNP granules captured in vivo

    Directory of Open Access Journals (Sweden)

    Jennifer E Bestman

    2009-01-01

    Full Text Available Cytoplasmic Polyadenylation Element Binding protein (CPEB is an RNA binding protein involved in dendritic delivery of mRNA and activity-dependent, polyadenylation-induced translation of mRNAs in the dendritic arbor. CPEB affects learning and memory and impacts neuronal morphological and synaptic plasticity. In neurons, CPEB is concentrated in ribonucleoprotein (RNP granules that distribute throughout the dendritic arbor and localize near synapses. We tagged full-length CPEB and an inactive mutant CPEB, that is incapable of triggering activity-induced mRNA translation, with fluorescent protein, then imaged rapid dendritic branch dynamics and RNP distribution using 2-photon time-lapse microscopy of neurons in the optic tectum of living Xenopus laevis tadpoles. The density of CPEB-containing RNP granules in dendrites is high and the distribution of granules does not correlate with sites of rapid dendritic branch dynamics. Nevertheless, inactive CPEB accumulates in granules in terminal dendritic branches, supporting the hypothesis that upon activation CPEB and its mRNA cargo are released from granules and are then available for dendritic translation.

  13. Phenotypical heterogeneity of testicular macrophages/dendritic cells in normal adult mice: an immunohistochemical study

    NARCIS (Netherlands)

    Itoh, M.; de rooij, D. G.; Jansen, A.; Drexhage, H. A.

    1995-01-01

    The distribution of macrophage/dendritic cell antigens was investigated immunohistochemically in frozen testis sections of normal A/J mice using a panel of rat monoclonal antibodies against murine macrophage/dendritic cell antigens (F4/80, BM8, MP23, MOMA1, MOMA2, M5/114, BMDM1 and NLDC145).

  14. Controlling T-Cell Activation with Synthetic Dendritic Cells Using the Multivalency Effect

    NARCIS (Netherlands)

    Hammink, R.; Mandal, S.; Eggermont, L.J.; Nooteboom, M.; Willems, P.H.G.M.; Tel, J.; Rowan, A.E.; Figdor, C.G.; Blank, K.G.

    2017-01-01

    Artificial antigen-presenting cells (aAPCs) have recently gained a lot of attention. They efficiently activate T cells and serve as powerful replacements for dendritic cells in cancer immunotherapy. Focusing on a specific class of polymer-based aAPCs, so-called synthetic dendritic cells (sDCs), we

  15. SK2 channel modulation contributes to compartment-specific dendritic plasticity in cerebellar Purkinje cells

    Science.gov (United States)

    Ohtsuki, Gen; Piochon, Claire; Adelman, John P.; Hansel, Christian

    2012-01-01

    Small-conductance Ca2+-activated K+ channels (SK channels) modulate excitability and curtail excitatory postsynaptic potentials (EPSPs) in neuronal dendrites. Here, we demonstrate long-lasting plasticity of intrinsic excitability (IE) in dendrites that results from changes in the gain of this regulatory mechanism. Using dendritic patch-clamp recordings from rat cerebellar Purkinje cells, we find that somatic depolarization or parallel fiber (PF) burst stimulation induce long-term amplification of synaptic responses to climbing fiber (CF) or PF stimulation, and enhance the amplitude of passively propagated sodium spikes. Dendritic plasticity is mimicked and occluded by the SK channel blocker apamin, and is absent in Purkinje cells from SK2 null mice. Triple-patch recordings from two dendritic sites and the soma, and confocal calcium imaging studies show that local stimulation limits dendritic plasticity to the activated compartment of the dendrite. This plasticity mechanism allows Purkinje cells to adjust the SK2-mediated control of dendritic excitability in an activity-dependent manner. PMID:22794265

  16. Dendritic Properties Control Energy Efficiency of Action Potentials in Cortical Pyramidal Cells.

    Science.gov (United States)

    Yi, Guosheng; Wang, Jiang; Wei, Xile; Deng, Bin

    2017-01-01

    Neural computation is performed by transforming input signals into sequences of action potentials (APs), which is metabolically expensive and limited by the energy available to the brain. The metabolic efficiency of single AP has important consequences for the computational power of the cell, which is determined by its biophysical properties and morphologies. Here we adopt biophysically-based two-compartment models to investigate how dendrites affect energy efficiency of APs in cortical pyramidal neurons. We measure the Na + entry during the spike and examine how it is efficiently used for generating AP depolarization. We show that increasing the proportion of dendritic area or coupling conductance between two chambers decreases Na + entry efficiency of somatic AP. Activating inward Ca 2+ current in dendrites results in dendritic spike, which increases AP efficiency. Activating Ca 2+ -activated outward K + current in dendrites, however, decreases Na + entry efficiency. We demonstrate that the active and passive dendrites take effects by altering the overlap between Na + influx and internal current flowing from soma to dendrite. We explain a fundamental link between dendritic properties and AP efficiency, which is essential to interpret how neural computation consumes metabolic energy and how biophysics and morphologies contribute to such consumption.

  17. Bidirectional shift in the cornu ammonis 3 pyramidal dendritic organization following brief stress

    NARCIS (Netherlands)

    Kole, M. H. P.; Costoli, T.; Koolhaas, J. M.; Fuchs, E.

    2004-01-01

    The negative impact of chronic stress at the structure of apical dendrite branches of cornu ammonis 3 (CA3) pyramidal neurons is well established. However, there is no information available on the CA3 dendritic organization related to short-lasting stress, which suffices to produce long-term

  18. Bidirectional shift in the cornu ammonis 3 pyramidal dendritic organization following brief stress

    NARCIS (Netherlands)

    Kole, MHP; Costoli, T; Koolhaas, JM; Fuchs, E

    2004-01-01

    The negative impact of chronic stress at the structure of apical dendrite branches of cornu ammonis 3 (CA3) pyramidal neurons is well established. However, there is no information available on the CA3 dendritic organization related to short-lasting stress, which suffices to produce longterm

  19. A dendrite-autonomous mechanism for direction selectivity in retinal starburst amacrine cells.

    Science.gov (United States)

    Hausselt, Susanne E; Euler, Thomas; Detwiler, Peter B; Denk, Winfried

    2007-07-01

    Detection of image motion direction begins in the retina, with starburst amacrine cells (SACs) playing a major role. SACs generate larger dendritic Ca(2+) signals when motion is from their somata towards their dendritic tips than for motion in the opposite direction. To study the mechanisms underlying the computation of direction selectivity (DS) in SAC dendrites, electrical responses to expanding and contracting circular wave visual stimuli were measured via somatic whole-cell recordings and quantified using Fourier analysis. Fundamental and, especially, harmonic frequency components were larger for expanding stimuli. This DS persists in the presence of GABA and glycine receptor antagonists, suggesting that inhibitory network interactions are not essential. The presence of harmonics indicates nonlinearity, which, as the relationship between harmonic amplitudes and holding potential indicates, is likely due to the activation of voltage-gated channels. [Ca(2+)] changes in SAC dendrites evoked by voltage steps and monitored by two-photon microscopy suggest that the distal dendrite is tonically depolarized relative to the soma, due in part to resting currents mediated by tonic glutamatergic synaptic input, and that high-voltage-activated Ca(2+) channels are active at rest. Supported by compartmental modeling, we conclude that dendritic DS in SACs can be computed by the dendrites themselves, relying on voltage-gated channels and a dendritic voltage gradient, which provides the spatial asymmetry necessary for direction discrimination.

  20. Endothelial cell-derived microparticles induce plasmacytoid dendritic cell maturation: potential implications in inflammatory diseases

    OpenAIRE

    Angelot, Fanny; Seillès, Estelle; Biichlé, Sabeha; Berda, Yael; Gaugler, Béatrice; Plumas, Joel; Chaperot, Laurence; Dignat-George, Françoise; Tiberghien, Pierre; Saas, Philippe; Garnache-Ottou, Francine

    2009-01-01

    International audience; BACKGROUND: Increased circulating endothelial microparticles, resulting from vascular endothelium dysfunction, and plasmacytoid dendritic cell activation are both encountered in common inflammatory disorders. The aim of our study was to determine whether interactions between endothelial microparticles and plasmacytoid dendritic cells could contribute to such pathologies. DESIGN AND METHODS: Microparticles generated from endothelial cell lines, platelets or activated T ...

  1. The shaping of two distinct dendritic spikes by A-type voltage-gated K+ channels

    Directory of Open Access Journals (Sweden)

    Sungchil eYang

    2015-12-01

    Full Text Available Dendritic ion channels have been a subject of intense research in neuroscience because active ion channels in dendrites shape input signals. Ca2+-permeable channels including NMDA receptors (NMDARs have been implicated in supralinear dendritic integration, and the IA conductance in sublinear integration. Despite their essential roles in dendritic integration, it has remained uncertain whether these conductances coordinate with, or counteract, each other in the process of dendritic integration. To address this question, experiments were designed in hippocampal CA1 neurons with a recent 3D digital holography system that has shown excellent performance for spatial photoactivation. The results demonstrated a role of IA as a key contributor to two distinct dendritic spikes, low- and high-threshold Ca2+ spikes, through a preferential action of IA on Ca2+-permeable channel-mediated currents, over fast AMPAR-mediated currents. It is likely that the rapid kinetics of IA provides feed-forward inhibition to counteract the delayed Ca2+ channel-mediated dendritic excitability. This research reveals one dynamic ionic mechanism of dendritic integration, and may contribute to a new understanding of neuronal hyperexcitability embedded in several neural diseases such as epilepsy, fragile X syndrome and Alzheimer's disease.

  2. A dendrite-autonomous mechanism for direction selectivity in retinal starburst amacrine cells.

    Directory of Open Access Journals (Sweden)

    Susanne E Hausselt

    2007-07-01

    Full Text Available Detection of image motion direction begins in the retina, with starburst amacrine cells (SACs playing a major role. SACs generate larger dendritic Ca(2+ signals when motion is from their somata towards their dendritic tips than for motion in the opposite direction. To study the mechanisms underlying the computation of direction selectivity (DS in SAC dendrites, electrical responses to expanding and contracting circular wave visual stimuli were measured via somatic whole-cell recordings and quantified using Fourier analysis. Fundamental and, especially, harmonic frequency components were larger for expanding stimuli. This DS persists in the presence of GABA and glycine receptor antagonists, suggesting that inhibitory network interactions are not essential. The presence of harmonics indicates nonlinearity, which, as the relationship between harmonic amplitudes and holding potential indicates, is likely due to the activation of voltage-gated channels. [Ca(2+] changes in SAC dendrites evoked by voltage steps and monitored by two-photon microscopy suggest that the distal dendrite is tonically depolarized relative to the soma, due in part to resting currents mediated by tonic glutamatergic synaptic input, and that high-voltage-activated Ca(2+ channels are active at rest. Supported by compartmental modeling, we conclude that dendritic DS in SACs can be computed by the dendrites themselves, relying on voltage-gated channels and a dendritic voltage gradient, which provides the spatial asymmetry necessary for direction discrimination.

  3. Classing it up to get noticed : MHC class 1 antigen display in dendritic cells and neuroblastoma

    NARCIS (Netherlands)

    Spel, Lotte

    2018-01-01

    In this thesis I have explored the process of MHC-1-mediated antigen presentation in two distinctive cell types: dendritic cells and neuroblastoma tumor cells. Dendritic cells (DCs) are pivotal players that bridge innate and adaptive immunity. DCs are able to engulf tumor-derived material and

  4. Specific Sorting and Post-Golgi trafficking of Dendritic Potassium Channels in Living Neurons

    DEFF Research Database (Denmark)

    Jensen, Camilla Stampe; Watanabe, Shoji; Rasmussen, Hanne Borger

    2014-01-01

    localization in distinct dendritic sub-compartments are largely unknown. Here, we developed a quantitative live-cell imaging method to analyze protein sorting and post-Golgi vesicular trafficking. We focused on two dendritic voltage-gated potassium channels which exhibit distinct localizations; Kv2...

  5. Calcium spikes and calcium plateaux evoked by differential polarization in dendrites of turtle motoneurones in vitro

    DEFF Research Database (Denmark)

    Hounsgaard, J; Kiehn, O

    1993-01-01

    The ability of dendrites in turtle motoneurones to support calcium spikes and calcium plateaux was investigated using differential polarization by applied electric fields. 2. Electric fields were generated by passing current through transverse slices of the turtle spinal cord between two plate......+ spikes and Ca2+ plateaux are present in dendrites of spinal motoneurones of the turtle....

  6. Development of Type 1 Diabetes: Monocytes and dendritic cells in the pancreas

    NARCIS (Netherlands)

    J.M.C. Welzen-Coppens (Jojanneke)

    2013-01-01

    textabstractThis thesis focuses on the presence of precursors for dendritic cells and the characterization of dendritic cell subsets in the normal pancreas in mice and humans as well as in the pancreas of the NOD mouse, a type 1 diabetes mouse model. Therefore, we give a short introduction to

  7. Exogenous dehydroisoandrosterone sulfate reverses the dendritic changes of the central neurons in aging male rats.

    Science.gov (United States)

    Chen, Jeng-Rung; Tseng, Guo-Fang; Wang, Yueh-Jan; Wang, Tsyr-Jiuan

    2014-09-01

    Sex hormones are known to help maintaining the cognitive ability in male and female rats. Hypogonadism results in the reduction of the dendritic spines of central neurons which is believed to undermine memory and cognition and cause fatigue and poor concentration. In our previous studies, we have reported age-related regression in dendrite arbors along with loss of dendritic spines in the primary somatosensory cortical neurons in female rats. Furthermore, castration caused a reduction of dendritic spines in adult male rats. In light of this, it was surmised that dendritic structures might change in normal aging male rats with advancing age. Recently, dehydroepiandrosterone sulfate (DHEAS) has been reported to have memory-enhancing properties in aged rodents. In this study, normal aging male rats, with a reduced plasma testosterone level of 75-80%, were used to explore the changes in behavioral performance of neuronal dendritic arbor and spine density. Aging rats performed poorer in spatial learning memory (Morris water maze). Concomitantly, these rats showed regressed dendritic arbors and spine loss on the primary somatosensory cortical and hippocampal CA1 pyramidal neurons. Exogenous DHEAS and testosterone treatment reversed the behavioral deficits and partially restored the spine loss of cortical neurons in aging male rats but had no effects on the dendritic arbor shrinkage of the affected neurons. It is concluded therefore that DHEAS, has the efficacy as testosterone, and that it can exert its effects on the central neuron level to effectively ameliorate aging symptoms. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. The extent to which melanoma alters tissue-resident dendritic cell function correlates with tumorigenicity

    OpenAIRE

    Hargadon, Kristian Michael

    2015-01-01

    ABSTRACT We have shown that melanoma-derived factors alter the function of differentiated tissue-resident dendritic cells (DC) in a tumorigenicity-dependent manner. Soluble factors, including TGF?1 and VEGF-A, contributed to dendritic cell dysfunction associated with a highly-aggressive melanoma and conferred a phenotype upon DC likely to favor immune escape and tumor outgrowth.

  9. The extent to which melanoma alters tissue-resident dendritic cell function correlates with tumorigenicity.

    Science.gov (United States)

    Hargadon, Kristian Michael

    We have shown that melanoma-derived factors alter the function of differentiated tissue-resident dendritic cells (DC) in a tumorigenicity-dependent manner. Soluble factors, including TGFβ1 and VEGF-A, contributed to dendritic cell dysfunction associated with a highly-aggressive melanoma and conferred a phenotype upon DC likely to favor immune escape and tumor outgrowth.

  10. CD1 and major histocompatibility complex II molecules follow a different course during dendritic cell maturation

    NARCIS (Netherlands)

    van der Wel, Nicole N.; Sugita, Masahiko; Fluitsma, Donna M.; Cao, Xaiochun; Schreibelt, Gerty; Brenner, Michael B.; Peters, Peter J.

    2003-01-01

    The maturation of dendritic cells is accompanied by the redistribution of major histocompatibility complex (MHC) class II molecules from the lysosomal MHC class IT compartment to the plasma membrane to mediate presentation of peptide antigens. Besides MHC molecules, dendritic cells also express CD1

  11. EVIDENCE OF CELL-NONAUTONOMOUS CHANGES IN DENDRITE AND DENDRITIC SPINE MORPHOLOGY IN THE MET-SIGNALING DEFICIENT MOUSE FOREBRAIN

    Science.gov (United States)

    Judson, Matthew C.; Eagleson, Kathie L.; Wang, Lily; Levitt, Pat

    2010-01-01

    Human genetic findings and murine neuroanatomical expression mapping have intersected to implicate Met receptor tyrosine kinase signaling in the development of forebrain circuits controlling social and emotional behaviors that are atypical in autism spectrum disorders (ASD). To clarify roles for Met signaling during forebrain circuit development in vivo, we generated mutant mice (Emx1Cre/Metfx/fx) with an Emx1-Cre-driven deletion of signaling-competent Met in dorsal pallially-derived forebrain neurons. Morphometric analyses of Lucifer Yellow-injected pyramidal neurons in postnatal day 40 anterior cingulate cortex (ACC) revealed no statistically significant changes in total dendritic length, but a selective reduction in apical arbor length distal to the soma in Emx1Cre/Metfx/fx neurons relative to wild type, consistent with a decrease in the total tissue volume sampled by individual arbors in the cortex. The effects on dendritic structure appear to be circuit-selective, as basal arbor length was increased in Emx1Cre/Metfx/fx layer 2/3 neurons. Spine number was not altered on Emx1Cre/Metfx/fx pyramidal cell populations studied, but spine head volume was significantly increased (~20%). Cell-nonautonomous, circuit-level influences of Met signaling on dendritic development were confirmed by studies of medium spiny neurons (MSN), which do not express Met, but receive Met-expressing corticostriatal afferents during development. Emx1Cre/Metfx/fx MSN exhibited robust increases in total arbor length (~20%). Like in the neocortex, average spine head volume was also increased (~12%). These data demonstrate that a developmental loss of presynaptic Met receptor signaling can affect postsynaptic morphogenesis and suggest a mechanism whereby attenuated Met signaling could disrupt both local and long-range connectivity within circuits relevant to ASD. PMID:20853516

  12. Numerical study of a cylinder model of the diffusion MRI signal for neuronal dendrite trees

    Science.gov (United States)

    Van Nguyen, Dang; Grebenkov, Denis; Le Bihan, Denis; Li, Jing-Rebecca

    2015-03-01

    We study numerically how the neuronal dendrite tree structure can affect the diffusion magnetic resonance imaging (dMRI) signal in brain tissue. For a large set of randomly generated dendrite trees, synthetic dMRI signals are computed and fitted to a cylinder model to estimate the effective longitudinal diffusivity DL in the direction of neurites. When the dendrite branches are short compared to the diffusion length, DL depends significantly on the ratio between the average branch length and the diffusion length. In turn, DL has very weak dependence on the distribution of branch lengths and orientations of a dendrite tree, and the number of branches per node. We conclude that the cylinder model which ignores the connectivity of the dendrite tree, can still be adapted to describe the apparent diffusion coefficient in brain tissue.

  13. Synthesis of palladium dendritic nanostructures on amidoxime modified polyacrylonitrile fibers through a complexing-reducing method

    International Nuclear Information System (INIS)

    Wu, Zhichuan; Zhang, Yong; Wang, Bo; Qian, Guixiang; Tao, Tingxian

    2013-01-01

    Highlights: • We report the assembly of Pd dendritic nanostructures on amidoxime modified polyacrylonitrile fibers. • The supply rate of the metallic Pd plays a critical role in the morphology of Pd nanostructures. • The possible mechanism of Pd dendritic nanostructures on fibers was proposed. -- Abstract: In this paper, three-dimensional fern-leaf-like palladium (Pd) dendritic nanostructures were successfully synthesized on amidoxime modified polyacrylonitrile fibers via a simple and efficient complexing-reducing method. The influence of reaction time, temperature, and concentrations of N 2 H 4 and Fe 3+ on the morphology and structure of Pd nanostructures was investigated. The results indicate that the supply rate of metallic Pd atoms plays a crucial role in the formation of the dendritic nanostructures. The formation mechanism of Pd dendritic nanostructures was proposed

  14. Synthesis of palladium dendritic nanostructures on amidoxime modified polyacrylonitrile fibers through a complexing-reducing method

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Zhichuan; Zhang, Yong; Wang, Bo; Qian, Guixiang; Tao, Tingxian, E-mail: tingxiantao@yahoo.cn

    2013-08-20

    Highlights: • We report the assembly of Pd dendritic nanostructures on amidoxime modified polyacrylonitrile fibers. • The supply rate of the metallic Pd plays a critical role in the morphology of Pd nanostructures. • The possible mechanism of Pd dendritic nanostructures on fibers was proposed. -- Abstract: In this paper, three-dimensional fern-leaf-like palladium (Pd) dendritic nanostructures were successfully synthesized on amidoxime modified polyacrylonitrile fibers via a simple and efficient complexing-reducing method. The influence of reaction time, temperature, and concentrations of N{sub 2}H{sub 4} and Fe{sup 3+} on the morphology and structure of Pd nanostructures was investigated. The results indicate that the supply rate of metallic Pd atoms plays a crucial role in the formation of the dendritic nanostructures. The formation mechanism of Pd dendritic nanostructures was proposed.

  15. Hierarchical Pd-Sn alloy nanosheet dendrites: an economical and highly active catalyst for ethanol electrooxidation.

    Science.gov (United States)

    Ding, Liang-Xin; Wang, An-Liang; Ou, Yan-Nan; Li, Qi; Guo, Rui; Zhao, Wen-Xia; Tong, Ye-Xiang; Li, Gao-Ren

    2013-01-01

    Hierarchical alloy nanosheet dendrites (ANSDs) are highly favorable for superior catalytic performance and efficient utilization of catalyst because of the special characteristics of alloys, nanosheets, and dendritic nanostructures. In this paper, we demonstrate for the first time a facile and efficient electrodeposition approach for the controllable synthesis of Pd-Sn ANSDs with high surface area. These synthesized Pd-Sn ANSDs exhibit high electrocatalytic activity and superior long-term cycle stability toward ethanol oxidation in alkaline media. The enhanced electrocataytic activity of Pd-Sn ANSDs may be attributed to Pd-Sn alloys, nanosheet dendrite induced promotional effect, large number of active sites on dendrite surface, large surface area, and good electrical contact with the base electrode. Because of the simple implement and high flexibility, the proposed approach can be considered as a general and powerful strategy to synthesize the alloy electrocatalysts with high surface areas and open dendritic nanostructures.

  16. Dual Functionalities of Carbon Nanotube Films for Dendrite-Free and High Energy-High Power Lithium-Sulfur Batteries.

    Science.gov (United States)

    Xie, Keyu; Yuan, Kai; Zhang, Kun; Shen, Chao; Lv, Weibang; Liu, Xingrui; Wang, Jian-Gan; Wei, Bingqing

    2017-02-08

    As a promising Li-metal battery, Li-S battery has an ultrahigh theoretical energy density of 2600 Wh kg -1 . However, most of the previous work has mainly focused on tackling the "polysulfide shuttle" originating from the S cathode, while the dendrite problem coming from the Li-metal anode has often been overlooked. Herein, to solve the issues arising from both the cathode and anode simultaneously, we propose a novel cell configuration for the first time by inserting CNT films on both sides of the separator in Li-S batteries, in which the cathode-side CNT film works as a shield to suppress the "polysulfide shuttle" and the anode-side CNT film acts as a powerful shield to prevent the Li dendrite growth. In the new cell configuration, the S/rGO cathode with a high S loading of about 4.0 mg cm -2 displays a high specific capacity (1336 mAh g -1 at 0.2 C), excellent rate ability (1070, 833, 656, and 444 mAh g -1 at 0.5, 1, 2, and 5 C, respectively), and sustainable cycling stability for 150 cycles with high Coulombic efficiency (>99%) at 1 C, while the Li metal anode displays an ultrasmooth surface. We believe this work will aid in developing other metal-based (e.g., Na, K, Zn, and Al) batteries.

  17. A Novel Long Non-coding RNA, durga Modulates Dendrite Density and Expression of kalirin in Zebrafish

    Science.gov (United States)

    Sarangdhar, Mayuresh A.; Chaubey, Divya; Bhatt, Abhishek; KM, Monisha; Kumar, Manish; Ranjan, Shashi; Pillai, Beena

    2017-01-01

    Kalirin, a key player in axonal development, nerve growth and synaptic re-modeling, is implicated in many pathological conditions like schizophrenia and autism-spectrum disorders. Alternative promoters and splicing lead to functionally distinct isoforms, but the post-transcriptional regulation of Kalirin has not been studied. Here, we report a novel non-coding RNA, which we name durga, arising from the first exon of kalirin a (kalrna) in the antisense orientation in zebrafish. The kalrna and durga transcripts are barely detectable during early development, but steadily increase by 24 hours post-fertilization (hpf) as the brain develops. Over-expression of durga in the zebrafish embryo led to an increase in kalrna expression. The morphology of the neurons cultured from durga injected embryos had significantly fewer and shorter dendrites. Although durga has no apparent sequence homolog in mammals, based on gene synteny, we found a non-coding RNA arising from the 5′ end of the human Kalrn gene and expressed in the human neuronal cell line, SH-SY5Y. We propose that the zebrafish lncRNA durga maintains dendritic length and density through regulation of kalrna expression and this may have further implications in mammalian systems. PMID:28442991

  18. Alterations in apical dendrite bundling in the somatosensory cortex of 5-HT3A receptor knockout mice.

    NARCIS (Netherlands)

    Smit-Rigter, L.A.; Wadman, W.J.; van Hooft, J.A.

    2011-01-01

    In various species and areas of the cerebral cortex, apical dendrites of pyramidal neurons form clusters which extend through several layers of the cortex also known as dendritic bundles. Previously, it has been shown that 5-HT3A receptor knockout mice show hypercomplex apical dendrites of cortical

  19. DMPD: Plasmacytoid dendritic cells: sensing nucleic acids in viral infection andautoimmune diseases. [Dynamic Macrophage Pathway CSML Database

    Lifescience Database Archive (English)

    Full Text Available 18641647 Plasmacytoid dendritic cells: sensing nucleic acids in viral infection andauto... (.csml) Show Plasmacytoid dendritic cells: sensing nucleic acids in viral infection andautoimmune diseases.... PubmedID 18641647 Title Plasmacytoid dendritic cells: sensing nucleic acids in viral infection andauto

  20. Arsenic and Growth of Amphistegina gibbosa

    Directory of Open Access Journals (Sweden)

    Elise Keister

    2009-01-01

    Full Text Available A laboratory tested various concentrations of arsenic on the growth of foraminifera and recorded their findings. Upon examination, the plotted probability density function for each of these trials resembled a similar shape. The plots were then characterized in a general model composed of linear segments. Using calculus, statistics such as the expected value, variance and standard deviation were calculated to interpret the collected data. The statistics revealed that arsenic limits the growth of ocean life.

  1. Cdk5 Is Essential for Amphetamine to Increase Dendritic Spine Density in Hippocampal Pyramidal Neurons

    Directory of Open Access Journals (Sweden)

    Soledad Ferreras

    2017-11-01

    Full Text Available Psychostimulant drugs of abuse increase dendritic spine density in reward centers of the brain. However, little is known about their effects in the hippocampus, where activity-dependent changes in the density of dendritic spine are associated with learning and memory. Recent reports suggest that Cdk5 plays an important role in drug addiction, but its role in psychostimulant’s effects on dendritic spines in hippocampus remain unknown. We used in vivo and in vitro approaches to demonstrate that amphetamine increases dendritic spine density in pyramidal neurons of the hippocampus. Primary cultures and organotypic slice cultures were used for cellular, molecular, pharmacological and biochemical analyses of the role of Cdk5/p25 in amphetamine-induced dendritic spine formation. Amphetamine (two-injection protocol increased dendritic spine density in hippocampal neurons of thy1-green fluorescent protein (GFP mice, as well as in hippocampal cultured neurons and organotypic slice cultures. Either genetic or pharmacological inhibition of Cdk5 activity prevented the amphetamine–induced increase in dendritic spine density. Amphetamine also increased spine density in neurons overexpressing the strong Cdk5 activator p25. Finally, inhibition of calpain, the protease necessary for the conversion of p35 to p25, prevented amphetamine’s effect on dendritic spine density. We demonstrate, for the first time, that amphetamine increases the density of dendritic spine in hippocampal pyramidal neurons in vivo and in vitro. Moreover, we show that the Cdk5/p25 signaling and calpain activity are both necessary for the effect of amphetamine on dendritic spine density. The identification of molecular mechanisms underlying psychostimulant effects provides novel and promising therapeutic approaches for the treatment of drug addiction.

  2. Functional Identification of Dendritic Cells in the Teleost Model, Rainbow Trout (Oncorhynchus mykiss)

    Science.gov (United States)

    Bassity, Elizabeth; Clark, Theodore G.

    2012-01-01

    Dendritic cells are specialized antigen presenting cells that bridge innate and adaptive immunity in mammals. This link between the ancient innate immune system and the more evolutionarily recent adaptive immune system is of particular interest in fish, the oldest vertebrates to have both innate and adaptive immunity. It is unknown whether dendritic cells co-evolved with the adaptive response, or if the connection between innate and adaptive immunity relied on a fundamentally different cell type early in evolution. We approached this question using the teleost model organism, rainbow trout (Oncorhynchus mykiss), with the aim of identifying dendritic cells based on their ability to stimulate naïve T cells. Adapting mammalian protocols for the generation of dendritic cells, we established a method of culturing highly motile, non-adherent cells from trout hematopoietic tissue that had irregular membrane processes and expressed surface MHCII. When side-by-side mixed leukocyte reactions were performed, these cells stimulated greater proliferation than B cells or macrophages, demonstrating their specialized ability to present antigen and therefore their functional homology to mammalian dendritic cells. Trout dendritic cells were then further analyzed to determine if they exhibited other features of mammalian dendritic cells. Trout dendritic cells were found to have many of the hallmarks of mammalian DCs including tree-like morphology, the expression of dendritic cell markers, the ability to phagocytose small particles, activation by toll-like receptor-ligands, and the ability to migrate in vivo. As in mammals, trout dendritic cells could be isolated directly from the spleen, or larger numbers could be derived from hematopoietic tissue and peripheral blood mononuclear cells in vitro. PMID:22427987

  3. Viral piracy: HIV-1 targets dendritic cells for transmission.

    Science.gov (United States)

    Lekkerkerker, Annemarie N; van Kooyk, Yvette; Geijtenbeek, Teunis B H

    2006-04-01

    Dendritic cells (DCs), the professional antigen presenting cells, are critical for host immunity by inducing specific immune responses against a broad variety of pathogens. Remarkably the human immunodeficiency virus-1 (HIV-1) subverts DC function leading to spread of the virus. At an early phase of HIV-1 transmission, DCs capture HIV-1 at mucosal surfaces and transmit the virus to T cells in secondary lymphoid tissues. Capture of the virus on DCs takes place via C-type lectins of which the dendritic cell-specific intercellular adhesion molecule-3 (ICAM-3) grabbing nonintegrin (DC-SIGN) is the best studied. DC-SIGN-captured HIV-1 particles accumulate in CD81(+) multivesicular bodies (MVBs) in DCs and are subsequently transmitted to CD4+ T cells resulting in infection of T cells. The viral cell-to-cell transmission takes place at the DC-T cell interface termed the infectious synapse. Recent studies demonstrate that direct infection of DCs contributes to the transmission to T cells at a later phase. Moreover, the infected DCs may function as cellular reservoirs for HIV-1. This review discusses the different processes that govern viral piracy of DCs by HIV-1, emphasizing the intracellular routing of the virus from capture on the cell surface to egress in the infectious synapse.

  4. Induction and identification of rabbit peripheral blood derived dendritic cells

    Science.gov (United States)

    Zhou, Jing; Yang, FuYuan; Chen, WenLi

    2012-03-01

    Purpose: To study a method of the induction of dendritic cells (DCs) from rabbit peripheral blood. Methods: Peripheral blood cells were removed from rabbit, filtered through nylon mesh. Peripheral blood mononuclear cells (PBMC) were isolated from the blood cells by Ficoll-Hypaque centrifugation (density of 1.077g/cm3).To obtain DCs, PBMC were cultured in RPMI1640 medium containing 10% fetal calf serum, 50U/mL penicillin and streptomycin, referred to subsequently as complete medium, at 37°C in 5% CO2 atmosphere for 4 hours. Nonadherent cells were aspirated, adherent cells were continued incubated in complete medium, supplemented with granulocyte/macrophage colony-stimulating factor (GM-CSF, 50ng/ml),and interleukin 4 (IL-4, 50ng/ml) for 9 days. Fluorescein labeled antibodies(anti-CD14, anti-HLA-DR, anti-CD86) were used to sign cells cultured for 3,6,9 days respectively, Then flow cytometry was performed. Results: Ratio of anti-HLA-DR and anti-CD86 labeled cells increased with induction time extension, in contrast with anti-CD14. Conclusion: Dendritic cells can be effectively induced by the method of this experiment, cell maturation status increased with induction time extension.

  5. Resistivity and thickness effects in dendritic web silicon solar cells

    Science.gov (United States)

    Meier, D. L.; Hwang, J. M.; Greggi, J.; Campbell, R. B.

    1987-01-01

    The decrease of minority carrier lifetime as resistivity decreases in dendritic-web silicon solar cells is addressed. This variation is shown to be consistent with the presence of defect levels in the bandgap which arise from extended defects in the web material. The extended defects are oxide precipitates (SiOx) and the dislocation cores they decorate. Sensitivity to this background distribution of defect levels increases with doping because the Fermi level moves closer to the majority carrier band edge. For high-resistivity dendritic-web silicon, which has a low concentration of these extended defects, cell efficiencies as high as 16.6 percent (4 sq cm, 40 ohm-cm boron-doped base, AM1.5 global, 100 mW/sq cm, 25 C JPL LAPSS1 measurement) and a corresponding electron lifetime of 38 microsec have been obtained. Thickness effects occur in bifacial cell designs and in designs which use light trapping. In some cases, the dislocation/precipitate defect can be passivated through the full thickness of web cells by hydrogen ion implantation.

  6. Stress, anxiety, and dendritic spines: what are the connections?

    Science.gov (United States)

    Leuner, B; Shors, T J

    2013-10-22

    Stressful life events, especially those that induce fear, can produce a state of anxiety that is useful for avoiding similar fearful and potentially dangerous situations in the future. However, they can also lead to exaggerated states, which over time can produce mental illness. These changing states of readiness versus illness are thought to be regulated, at least in part, by alterations in dendritic and synaptic structure within brain regions known to be involved in anxiety. These regions include the amygdala, hippocampus, and prefrontal cortex. In this article, we review the reciprocal relationships between the expression of stress- and anxiety-related behaviors and stress-induced morphological plasticity as detected by changes in dendrites and spines in these three brain regions. We begin by highlighting the acute and chronic effects of stress on synaptic morphology in each area and describe some of the putative mechanisms that have been implicated in these effects. We then discuss the functional consequences of stress-induced structural plasticity focusing on synaptic plasticity as well as cognitive and emotional behaviors. Finally, we consider how these structural changes may contribute to adaptive behaviors as well as maladaptive responses associated with anxiety. Copyright © 2012 IBRO. Published by Elsevier Ltd. All rights reserved.

  7. Blastic plasmacytoid dendritic cell neoplasm: challenges and future prospects

    Directory of Open Access Journals (Sweden)

    Trottier AM

    2017-12-01

    Full Text Available Amy M Trottier, Sonia Cerquozzi, Carolyn J Owen Division of Hematology and Hematological Malignancies, University of Calgary, Foothills Medical Centre, Calgary, AB, Canada Abstract: Blastic plasmacytoid dendritic cell neoplasm (BPDCN is a rare CD4+ CD56+ myeloid malignancy that is challenging to diagnose and treat. BPDCN typically presents with nonspecific cutaneous lesions with or without extra-cutaneous manifestations before progressing to leukemia. Currently, there is no standard of care for the treatment of BPDCN and various approaches have been used including acute myeloid leukemia, acute lymphoblastic leukemia, and lymphoma-based regimens with or without stem cell transplantation. Despite these treatment approaches, the prognosis of BPDCN remains poor and there is a lack of prospective data upon which to base treatment decisions. Recent work examining the mutational landscape and gene expression profiles of BPDCN has identified a number of potential therapeutic targets. One such target is CD123, the α subunit of the human interleukin-3 receptor, which is the subject of intervention studies using the novel agent SL-401. Other investigational therapies include UCART123, T-cell immunotherapy, and venetoclax. Prospective trials are needed to determine the best treatment for this uncommon and aggressive neoplasm. Keywords: BPDCN, myeloid, neoplasm, cutaneous, dendritic cell

  8. Dendritic spine morphology and dynamics in health and disease

    Directory of Open Access Journals (Sweden)

    Lee S

    2015-06-01

    Full Text Available Stacey Lee,1 Huaye Zhang,2 Donna J Webb1,3,4 1Department of Biological Sciences, Vanderbilt University, Nashville, TN, 2Department of Neuroscience and Cell Biology, Rutgers Robert Wood Johnson Medical School, Piscataway, NJ, 3Department of Cancer Biology, 4Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University, Nashville, TN, USA Abstract: Dendritic spines are actin-rich structures that form the postsynaptic terminals of excitatory synapses in the brain. The development and plasticity of spines are essential for cognitive processes, such as learning and memory, and defects in their density, morphology, and size underlie a number of neurological disorders. In this review, we discuss the contribution and regulation of the actin cytoskeleton in spine formation and plasticity as well as learning and memory. We also highlight the role of key receptors and intracellular signaling pathways in modulating the development and morphology of spines and cognitive function. Moreover, we provide insight into spine/synapse defects associated with several neurological disorders and the molecular mechanisms that underlie these spine defects. Keywords: dendritic spines, synapses, synaptic plasticity, actin cytoskeleton, glutamate receptors, neurological disorders

  9. An Investigation into the Mechanics of Windblown Dust Entrainment from Nickel Slag Surfaces Resembling Armoured Desert Pavements

    Science.gov (United States)

    Sanderson, Robert Steven

    The purpose of this thesis is to investigate the dynamics of PM 10 emission from a nickel slag stockpile that closely resembles a desert pavement in physical characteristics. In the field, it was observed that slag surfaces develop by natural processes into a well-armoured surface over some period of time. The surface then consists of two distinct layers; a surficial armour layer containing only non-erodible gravel and cobble-sized clasts, and an underlying dust-laden layer, which contains a wide size range of slag particles, from clay-sized to cobble-sized. This surficial armour layer protects the underlying fines from wind entrainment, at least under typical wind conditions; however, particle emissions still do occur under high wind speeds. The dynamics of particle entrainment from within these surfaces are investigated herein. It is shown that the dynamics of the boundary layer flow over these lag surfaces are influenced by the inherent roughness and permeability of the surficial armour layer, such that the flow resembles those observed over and within vegetation canopies, and those associated with permeable gravel-bed river channels. Restriction of air flow within the permeable surface produces a high-pressure zone within the pore spaces, resulting in a Kelvin-Helmholtz shear instability, which triggers coherent motions in the form of repeating burst-sweep cycles. Using Laser Doppler Anemometry (LDA), it is demonstrated that the lower boundary layer is characterized by both Q4 sweeping motions and Q2 bursting motions, while the upper boundary layer is dominated by Q2 bursts. Pore air motions within the slag material were measured using buried pressure ports. It is shown that the mean pressure gradient which forms within the slag material results in net upward displacement of air, or wind pumping. However, this net upward motion is a result of rapid oscillatory motions which are directly driven by coherent boundary layer motions. It is also demonstrated that

  10. Muscle-type nicotinic receptor modulation by 2,6-dimethylaniline, a molecule resembling the hydrophobic moiety of lidocaine

    Directory of Open Access Journals (Sweden)

    Armando Alberola-Die

    2016-11-01

    Full Text Available To identify the molecular determinants responsible for lidocaine blockade of muscle-type nAChRs, we have studied the effects on this receptor of 2,6-dimethylaniline (DMA, which resembles lidocaine’s hydrophobic moiety. Torpedo marmorata nAChRs were microtransplanted to Xenopus oocytes and currents elicited by ACh (IACh, either alone or co-applied with DMA, were recorded. DMA reversibly blocked IACh and, similarly to lidocaine, exerted a closed-channel blockade, as evidenced by the enhancement of IACh blockade when DMA was pre-applied before its co-application with ACh, and hastened IACh decay. However, there were marked differences among its mechanisms of nAChR inhibition and those mediated by either the entire lidocaine molecule or diethylamine (DEA, a small amine resembling lidocaine’s hydrophilic moiety. Thereby, the IC50 for DMA, estimated from the dose-inhibition curve, was in the millimolar range, which is one order of magnitude higher than that for either DEA or lidocaine. Besides, nAChR blockade by DMA was voltage-independent in contrast to the increase of IACh inhibition at negative potentials caused by the more polar lidocaine or DEA molecules. Accordingly, virtual docking assays of DMA on nAChRs showed that this molecule binds predominantly at intersubunit crevices of the transmembrane-spanning domain, but also at the extracellular domain. Furthermore, DMA interacted with residues inside the channel pore, although only in the open-channel conformation. Interestingly, co-application of ACh with DEA and DMA, at their IC50s, had additive inhibitory effects on IACh and the extent of blockade was similar to that predicted by the allotopic model of interaction, suggesting that DEA and DMA bind to nAChRs at different loci. These results indicate that DMA mainly mimics the low potency and non-competitive actions of lidocaine on nAChRs, as opposed to the high potency and voltage-dependent block by lidocaine, which is emulated by the

  11. Vaginal microbiota of adolescent girls prior to the onset of menarche resemble those of reproductive-age women.

    Science.gov (United States)

    Hickey, Roxana J; Zhou, Xia; Settles, Matthew L; Erb, Julie; Malone, Kristin; Hansmann, Melanie A; Shew, Marcia L; Van Der Pol, Barbara; Fortenberry, J Dennis; Forney, Larry J

    2015-03-24

    Puberty is an important developmental stage wherein hormonal shifts mediate the physical and physiological changes that lead to menarche, but until now, the bacterial composition of vaginal microbiota during this period has been poorly characterized. We performed a prospective longitudinal study of perimenarcheal girls to gain insight into the timing and sequence of changes that occur in the vaginal and vulvar microbiota during puberty. The study enrolled 31 healthy, premenarcheal girls between the ages of 10 and 12 years and collected vaginal and vulvar swabs quarterly for up to 3 years. Bacterial composition was characterized by Roche 454 pyrosequencing and classification of regions V1 to V3 of 16S rRNA genes. Contrary to expectations, lactic acid bacteria, primarily Lactobacillus spp., were dominant in the microbiota of most girls well before the onset of menarche in the early to middle stages of puberty. Gardnerella vaginalis was detected at appreciable levels in approximately one-third of subjects, a notable finding considering that this organism is commonly associated with bacterial vaginosis in adults. Vulvar microbiota closely resembled vaginal microbiota but often exhibited additional taxa typically associated with skin microbiota. Our findings suggest that the vaginal microbiota of girls begin to resemble those of adults well before the onset of menarche. This study addresses longitudinal changes in vaginal and vulvar microbial communities prior to and immediately following menarche. The research is significant because microbial ecology of the vagina is an integral aspect of health, including resistance to infections. The physiologic changes of puberty and initiation of cyclic menstruation are likely to have profound effects on vaginal microbiota, but almost nothing is known about changes that normally occur during this time. Our understanding has been especially hampered by the lack of thorough characterization of microbial communities using techniques

  12. Genomic patterns resembling BRCA1- and BRCA2-mutated breast cancers predict benefit of intensified carboplatin-based chemotherapy

    Science.gov (United States)

    2014-01-01

    Introduction BRCA-mutated breast cancer cells lack the DNA-repair mechanism homologous recombination that is required for error-free DNA double-strand break (DSB) repair. Homologous recombination deficiency (HRD) may cause hypersensitivity to DNA DSB-inducing agents, such as bifunctional alkylating agents and platinum salts. HRD can be caused by BRCA mutations, and by other mechanisms. To identify HRD, studies have focused on triple-negative (TN) breast cancers as these resemble BRCA1-mutated breast cancer closely and might also share this hypersensitivity. However, ways to identify HRD in non-BRCA-mutated, estrogen receptor (ER)-positive breast cancers have remained elusive. The current study provides evidence that genomic patterns resembling BRCA1- or BRCA2-mutated breast cancers can identify breast cancer patients with TN as well as ER-positive, HER2-negative tumors that are sensitive to intensified, DSB-inducing chemotherapy. Methods Array comparative genomic hybridization (aCGH) was used to classify breast cancers. Patients with tumors with similar aCGH patterns as BRCA1- and/or BRCA2-mutated breast cancers were defined as having a BRCA-likeCGH status, others as non-BCRA-likeCGH. Stage-III patients (n = 249) had participated in a randomized controlled trial of adjuvant high-dose (HD) cyclophosphamide-thiotepa-carboplatin (CTC) versus 5-fluorouracil-epirubicin-cyclophosphamide (FE90C) chemotherapy. Results Among patients with BRCA-likeCGH tumors (81/249, 32%), a significant benefit of HD-CTC compared to FE90C was observed regarding overall survival (adjusted hazard ratio 0.19, 95% CI: 0.08 to 0.48) that was not seen for patients with non-BRCA-likeCGH tumors (adjusted hazard ratio 0.90, 95% CI: 0.53 to 1.54) (P = 0.004). Half of all BRCA-likeCGH tumors were ER-positive. Conclusions Distinct aCGH patterns differentiated between HER2-negative patients with a markedly improved outcome after adjuvant treatment with an intensified DNA-DSB-inducing regimen

  13. Tectonic resemblance of the Indian Platform, Pakistan with the Moesian Platform, Romania and strategy for exploration of hydrocarbons

    International Nuclear Information System (INIS)

    Memon, A.D.

    1994-01-01

    There is a remarkable tectonic resemblance between the indian Platform (Pakistan) and the Moesian Platform (Romania). As viewed in global tectonic perspective Moeslan and Indian Plates have played important role in Alpine Himalayan Orogeny; Moesian and Indian Platforms are extension of these respective plates. Characteristics features of both the platforms are block faulting which has effected not only the general tectonic framework but has also played important role in oil accumulation. Main producing rocks in the Moesian platform are Jurassic sandstones and cretaceous limestones while in the indian platform cretaceous sandstones are important reservoirs. The average geothermal gradient in the indian platform is 2.45 C/100m with the higher gradients in the central gas producing region. Geothermal gradients in the Moesian platform have an average value of 3 C/100m with higher gradients in the northern in the northern part. Some of the producing structures in both the platforms are remarkably similar, traps associated with normal faults are very important. Extensive exploration carried in the Moesian Platform makes it very important oil producing region of Romania. After the discovery of oil lower Sindh, serious exploration is being carried in the Indian platform. The paper deals with the similarities between these two important platforms. In the light of the studies of the Moesian platform, strategies or exploration of oil and gas in the Indian Platform are suggested. (author)

  14. Resting-state fMRI in sleeping infants more closely resembles adult sleep than adult wakefulness.

    Directory of Open Access Journals (Sweden)

    Anish Mitra

    Full Text Available Resting state functional magnetic resonance imaging (rs-fMRI in infants enables important studies of functional brain organization early in human development. However, rs-fMRI in infants has universally been obtained during sleep to reduce participant motion artifact, raising the question of whether differences in functional organization between awake adults and sleeping infants that are commonly attributed to development may instead derive, at least in part, from sleep. This question is especially important as rs-fMRI differences in adult wake vs. sleep are well documented. To investigate this question, we compared functional connectivity and BOLD signal propagation patterns in 6, 12, and 24 month old sleeping infants with patterns in adult wakefulness and non-REM sleep. We find that important functional connectivity features seen during infant sleep closely resemble those seen during adult sleep, including reduced default mode network functional connectivity. However, we also find differences between infant and adult sleep, especially in thalamic BOLD signal propagation patterns. These findings highlight the importance of considering sleep state when drawing developmental inferences in infant rs-fMRI.

  15. Phenotypically resembling myeloid derived suppressor cells are increased in children with HIV and exposed/infected with Mycobacterium tuberculosis.

    Science.gov (United States)

    Du Plessis, Nelita; Jacobs, Ruschca; Gutschmidt, Andrea; Fang, Zhuo; van Helden, Paul D; Lutz, Manfred B; Hesseling, Anneke C; Walzl, Gerhard

    2017-01-01

    Increased disease susceptibility during early life has been linked to immune immaturity, regulatory T-cell/TH2 immune biasing and hyporesponsiveness. The contribution of myeloid derived suppressor cells (MDSCs) remains uninvestigated. Here, we assessed peripheral MDSC in HIV-infected and -uninfected children with tuberculosis (TB) disease before, during and after TB treatment, along with matched household contacts (HHCs), HIV-exposed, -infected and -uninfected children without recent TB exposure. Serum analytes and enzymes associated with MDSC accumulation/activation/function were measured by colorimetric- and fluorescence arrays. Peripheral frequencies of cells phenotypically resembling MDSCs were significantly increased in HIV-exposed uninfected (HEU) and M.tb-infected children, but peaked in children with TB disease and remained high following treatment. MDSC in HIV-infected (HI) children were similar to unexposed uninfected controls; however, HAART-mediated MDSC restoration to control levels could not be disregarded. Increased MDSC frequencies in HHC coincided with enhanced indoleamine-pyrrole-2,3-dioxygenase (IDO), whereas increased MDSC in TB cases were linked to heightened IDO and arginase-1. Increased MDSC were paralleled by reduced plasma IP-10 and thrombospondin-2 levels in HEU and significantly increased plasma IL-6 in HI HHC. Current investigations into MDSC-targeted treatment strategies, together with functional analyses of MDSCs, could endorse these cells as novel innate immune regulatory mechanism of infant HIV/TB susceptibility. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Primary new-onset hydroceles presenting in late childhood and pre-adolescent patients resemble the adult type hydrocele pathology.

    Science.gov (United States)

    Koutsoumis, Georgios; Patoulias, Ioannis; Kaselas, Christos

    2014-11-01

    The aim of this study was to investigate the presence of a patent processus vaginalis (PPV) in children of late childhood and pre-adolescence presenting with new onset hydrocele. All males with hydrocele presenting at our department from January 2011 to January 2013 were followed. Patients with secondary hydroceles were excluded. Demographic data, medical history, clinical symptoms and signs relative to their pathology and U/S findings were recorded. According to their indications, patients were either operated or followed up. Patients surgically treated, consisted our study group. Sixty patients were identified. Thirteen were followed until resolution of their hydrocele. Forty-seven patients were surgically treated. Twenty-seven had right sided hydrocele (57.44%), 13 had left sided hydrocele (27.66%) whereas in 7 patients the hydroceles were bilateral (14.9%). All patients were operated by an inguinal approach. In all 9 patients (19.14%) presenting with new-onset hydrocele at the age >10 years (range: 10-15 years), intraoperative exploration did not reveal a PPV. All patients were followed at least for 6 months post-operatively. Early evidence shows that primary new onset hydroceles presenting in late childhood and pre-adolescence seem to be non-communicating and resemble the adult type hydrocele pathology. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. Combined exposure to bacteria and cigarette smoke resembles characteristic phenotypes of human COPD in a murine disease model.

    Science.gov (United States)

    Herr, Christian; Han, Gang; Li, Dong; Tschernig, Thomas; Dinh, Quoc Thai; Beißwenger, Christoph; Bals, Robert

    2015-03-01

    Abundant microbial colonization is a hallmark of COPD and smoke exposure likely increases the susceptibility to colonization and infection. The aim of the present study was to characterize the pulmonary changes of a combined exposure to cigarette smoke (CS) and microbial challenge in a preclinical murine COPD model. Animals were exposed to CS for 2 weeks, 3, and 6 months. Low and high doses of heat inactivated nontypeable Haemophilus influenzae (NTHi) were administered by inhalation during the whole exposure time. Pulmonary changes were analyzed by stereology, pulmonary function tests, measurements of inflammatory cells and mediators, and histopathology. Exposure of smoke in a relatively low concentration caused COPD-like changes of pulmonary function and only little inflammation. The coadministration of low dose NTHi (ld-NTHi) augmented a macrophage dominated inflammatory profile, while high dose NTHi (hd-NTHi) induced a neutrophilic inflammatory pattern. IL-17A secretion was solely dependent on the exposure to NTHi. Also goblet cell metaplasia and the formation of lymphoid aggregates depended on exposure to bacteria. In conclusion, the combination of exposure to smoke and bacterial compounds resulted in a mouse model that resembles several aspects of human disease. Exposure to microbial structural components appears necessary to model important pathologic features of the disease and the quantity of the exposure with microorganisms has a strong effect on the phenotype. Copyright © 2015 Elsevier GmbH. All rights reserved.

  18. Chemoresistance of human monocyte-derived dendritic cells is regulated by IL-17A.

    Directory of Open Access Journals (Sweden)

    Selma Olsson Åkefeldt

    Full Text Available Dendritic cells initiate adaptive immune responses, leading either to control cancer by effector T cells or to exacerbate cancer by regulatory T cells that inhibit IFN-γ-mediated Th1-type response. Dendritic cells can also induce Th17-type immunity, mediated by IL-17A. However, the controversial role of this cytokine in cancer requires further investigations. We generated dendritic cells from peripheral blood monocytes to investigate lifespan, phenotype and chemoresistance of dendritic cells, treated with IL-17A with or without IFN-γ. Studying the expression of Bcl-2 family members, we demonstrated that dendritic cells constitutively express one pro-survival Bcl-2 member: MCL1. Immature dendritic cells were CD40(lowHLADR(low CD1a(+ MCL1(+, did not express CD14, CD68 or BCL2A1, and displayed a short 2-day lifespan. IL-17A-treated DC exhibited a semi-mature (CD40(high HLADR(low pre-M2 (CCL22(+ CD206(+ CD163(+ IL1RN(+ IL-10(- CXCL10(- IL-12(- mixed (CD1a(+ CD14+ CD68(+ macrophage-dendritic cell phenotype. They efficiently exerted mannose receptor-mediated endocytosis and did not produce superoxide anions, in the absence of TLR engagement. Interestingly, IL-17A promoted a long-term survival of dendritic cells, beyond 12 days, that correlated to BCL2A1 induction, a pro-survival Bcl-2 family member. BCL2A1 transcription was activated by NF-κB, downstream of IL-17A transduction. Thus, immature dendritic cells only express MCL1, whereas IL-17A-treated dendritic cells concomitantly expressed two pro-survival Bcl-2 family members: MCL1 and BCL2A1. These latter developed chemoresistance to 11 of the 17 chemotherapy agents tested. However, high doses of either vinblastine or cytarabine decreased MCL1 expression and induced dendritic cell death. When IL-17A is produced in vivo, administration of anti-IL-17A biotherapy may impair dendritic cell survival by targeting BCL2A1 expression. Consequently, depending on the effector or regulatory role of dendritic

  19. Antibacterial Compounds of Canadian Honeys Target Bacterial Cell Wall Inducing Phenotype Changes, Growth Inhibition and Cell Lysis That Resemble Action of β-Lactam Antibiotics

    OpenAIRE

    Brudzynski, Katrina; Sjaarda, Calvin

    2014-01-01

    Honeys show a desirable broad spectrum activity against Gram-positive and negative bacteria making antibacterial activity an intrinsic property of honey and a desirable source for new drug development. The cellular targets and underlying mechanism of action of honey antibacterial compounds remain largely unknown. To facilitate the target discovery, we employed a method of phenotypic profiling by directly comparing morphological changes in Escherichia coli induced by honeys to that of ampicill...

  20. Inorganic arsenic impairs differentiation and functions of human dendritic cells

    Energy Technology Data Exchange (ETDEWEB)

    Macoch, Mélinda; Morzadec, Claudie [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Fardel, Olivier [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France); Pôle Biologie, Centre Hospitalier Universitaire (CHU) Rennes, 2 rue Henri Le Guilloux, 35033 Rennes (France); Vernhet, Laurent, E-mail: laurent.vernhet@univ-rennes1.fr [UMR INSERM U1085, Institut de Recherche sur la Santé, l' Environnement et le Travail (IRSET), Université de Rennes 1, 2 avenue du Professeur Léon Bernard, 35043 Rennes (France)

    2013-01-15

    Experimental studies have demonstrated that the antileukemic trivalent inorganic arsenic prevents the development of severe pro-inflammatory diseases mediated by excessive Th1 and Th17 cell responses. Differentiation of Th1 and Th17 subsets is mainly regulated by interleukins (ILs) secreted from dendritic cells (DCs) and the ability of inorganic arsenic to impair interferon-γ and IL-17 secretion by interfering with the physiology of DCs is unknown. In the present study, we demonstrate that high concentrations of sodium arsenite (As(III), 1–2 μM) clinically achievable in plasma of arsenic-treated patients, block differentiation of human peripheral blood monocytes into immature DCs (iDCs) by inducing their necrosis. Differentiation of monocytes in the presence of non-cytotoxic concentrations of As(III) (0.1 to 0.5 μM) only slightly impacts endocytotic activity of iDCs or expression of co-stimulatory molecules in cells activated with lipopolysaccharide. However, this differentiation in the presence of As(III) strongly represses secretion of IL-12p70 and IL-23, two major regulators of Th1 and Th17 activities, from iDCs stimulated with different toll-like receptor (TLR) agonists in metalloid-free medium. Such As(III)-exposed DCs also exhibit reduced mRNA levels of IL12A and/or IL12B genes when activated with TLR agonists. Finally, differentiation of monocytes with non-cytotoxic concentrations of As(III) subsequently reduces the ability of activated DCs to stimulate the release of interferon-γ and IL-17 from Th cells. In conclusion, our results demonstrate that clinically relevant concentrations of inorganic arsenic markedly impair in vitro differentiation and functions of DCs, which may contribute to the putative beneficial effects of the metalloid towards inflammatory autoimmune diseases. Highlights: ► Inorganic arsenic impairs differentiation and functions of human dendritic cells (DCs) ► Arsenite (> 1 μM) blocks differentiation of dendritic cells by