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Sample records for genetically encoded calcium

  1. Visualizing presynaptic calcium dynamics and vesicle fusion with a single genetically encoded reporter at individual synapses

    Rachel E Jackson

    2016-07-01

    Full Text Available Synaptic transmission depends on the influx of calcium into the presynaptic compartment, which drives neurotransmitter release. Genetically encoded reporters are widely used tools to understand these processes, particularly pHluorin-based reporters that report vesicle exocytosis and endocytosis through pH dependent changes in fluorescence, and genetically encoded calcium indicators (GECIs that exhibit changes in fluorescence upon binding to calcium. The recent expansion of the color palette of available indicators has made it possible to image multiple probes simultaneously within a cell. We have constructed a single molecule reporter capable of concurrent imaging of both presynaptic calcium influx and exocytosis, by fusion of sypHy, the vesicle associated protein synaptophysin containing a GFP-based pHluorin sensor, with the red-shifted GECI R-GECO1. Due to the fixed stoichiometry of the two probes, the ratio of the two responses can also be measured, providing an all optical correlate of the calcium dependence of release. Here, we have characterized stimulus-evoked sypHy-RGECO responses of hippocampal synapses in vitro, exploring the effects of different stimulus strengths and frequencies as well as variations in external calcium concentrations. By combining live sypHy-RGECO imaging with post-hoc fixation and immunofluorescence, we have also investigated correlations between structural and functional properties of synapses.

  2. Genetically encoded calcium indicators for multi-color neural activity imaging and combination with optogenetics

    Jasper eAkerboom

    2013-03-01

    Full Text Available Genetically encoded calcium indicators (GECIs are powerful tools for systems neuroscience. Here we describe red, single-wavelength GECIs, RCaMPs, engineered from circular permutation of the thermostable red fluorescent protein mRuby. High-resolution crystal structures of mRuby, the red sensor RCaMP, and the recently published red GECI R-GECO1 give insight into the chromophore environments of the Ca2+-bound state of the sensors and the engineered protein domain interfaces of the different indicators. We characterized the biophysical properties and performance of RCaMP sensors in vitro and in vivo in Caenorhabditis elegans, Drosophila larvae, and larval zebrafish. Further, we demonstrate 2-color calcium imaging both within the same cell (registering mitochondrial and somatic [Ca2+] and between two populations of cells: neurons and astrocytes. Finally, we perform integrated optogenetics experiments, wherein neural activation via channelrhodopsin-2 (ChR2 or a red-shifted variant, and activity imaging via RCaMP or GCaMP, are conducted simultaneously, with the ChR2/RCaMP pair providing independently addressable spectral channels. Using this paradigm, we measure calcium responses of naturalistic and ChR2-evoked muscle contractions in vivo in crawling C. elegans. We systematically compare the RCaMP sensors to R-GECO1, in terms of action potential-evoked fluorescence increases in neurons, photobleaching, and photoswitching. R-GECO1 displays higher Ca2+ affinity and larger dynamic range than RCaMP, but exhibits significant photoactivation with blue and green light, suggesting that integrated channelrhodopsin-based optogenetics using R-GECO1 may be subject to artifact. Finally, we create and test blue, cyan and yellow variants engineered from GCaMP by rational design. This engineered set of chromatic variants facilitates new experiments in functional imaging and optogenetics.

  3. Imaging activity in astrocytes and neurons with genetically encoded calcium indicators following in utero electroporation

    J. Michael eGee

    2015-04-01

    Full Text Available Complex interactions between networks of astrocytes and neurons are beginning to be appreciated, but remain poorly understood. Transgenic mice expressing fluorescent protein reporters of cellular activity, such as the GCaMP family of genetically encoded calcium indicators, have been used to explore network behavior. However, in some cases, it may be desirable to use long-established rat models that closely mimic particular aspects of human conditions such as Parkinson’s disease and the development of epilepsy following status epilepticus. Methods for expressing reporter proteins in the rat brain are relatively limited. Transgenic rat technologies exist but are fairly immature. Viral-mediated expression is robust but unstable, requires invasive injections, and only works well for fairly small genes (< 5 kb. In utero electroporation offers a valuable alternative. IUE is a proven method for transfecting populations of astrocytes and neurons in the rat brain without the strict limitations on transgene size. We built a toolset of IUE plasmids carrying GCaMP variants 3, 6s or 6f driven by CAG and targeted to the cytosol or the plasma membrane. Because low baseline fluorescence of GCaMP can hinder identification of transfected cells, we included the option of co-expressing a cytosolic tdTomato protein. A binary system consisting of a plasmid carrying a piggyBac inverted terminal repeat-flanked CAG-GCaMP-IRES-tdTomato cassette and a separate plasmid encoding for expression of piggyBac transposase was employed to stably express GCaMP and tdTomato. The plasmids were co-electroporated on embryonic days 13.5-14.5 and astrocytic and neuronal activity was subsequently imaged in acute or cultured brain slices prepared from the cortex or hippocampus. Large spontaneous transients were detected in slices obtained from rats of varying ages up to 127 days. In this report, we demonstrate the utility of this toolset for interrogating astrocytic and neuronal

  4. Crystallization and preliminary X-ray characterization of the genetically encoded fluorescent calcium indicator protein GCaMP2

    Rodríguez Guilbe, María M.; Alfaro Malavé, Elisa C.; Akerboom, Jasper; Marvin, Jonathan S.; Looger, Loren L.; Schreiter, Eric R.

    2008-01-01

    The genetically encoded fluorescent calcium-indicator protein GCaMP2 was crystallized in the calcium-saturated form. X-ray diffraction data were collected to 2.0 Å resolution and the structure was solved by molecular replacement. Fluorescent proteins and their engineered variants have played an important role in the study of biology. The genetically encoded calcium-indicator protein GCaMP2 comprises a circularly permuted fluorescent protein coupled to the calcium-binding protein calmodulin and a calmodulin target peptide, M13, derived from the intracellular calmodulin target myosin light-chain kinase and has been used to image calcium transients in vivo. To aid rational efforts to engineer improved variants of GCaMP2, this protein was crystallized in the calcium-saturated form. X-ray diffraction data were collected to 2.0 Å resolution. The crystals belong to space group C2, with unit-cell parameters a = 126.1, b = 47.1, c = 68.8 Å, β = 100.5° and one GCaMP2 molecule in the asymmetric unit. The structure was phased by molecular replacement and refinement is currently under way

  5. Visualisation of an nsPEF induced calcium wave using the genetically encoded calcium indicator GCaMP in U87 human glioblastoma cells.

    Carr, Lynn; Bardet, Sylvia M; Arnaud-Cormos, Delia; Leveque, Philippe; O'Connor, Rodney P

    2018-02-01

    Cytosolic, synthetic chemical calcium indicators are typically used to visualise the rapid increase in intracellular calcium ion concentration that follows nanosecond pulsed electric field (nsPEF) application. This study looks at the application of genetically encoded calcium indicators (GECIs) to investigate the spatiotemporal nature of nsPEF-induced calcium signals using fluorescent live cell imaging. Calcium responses to 44kV/cm, 10ns pulses were observed in U87-MG cells expressing either a plasma membrane targeted GECI (GCaMP5-G), or one cytosolically expressed (GCaMP6-S), and compared to the response of cells loaded with cytosolic or plasma membrane targeted chemical calcium indicators. Application of 100 pulses, to cells containing plasma membrane targeted indicators, revealed a wave of calcium across the cell initiating at the cathode side. A similar spatial wave was not observed with cytosolic indicators with mobile calcium buffering properties. The speed of the wave was related to pulse application frequency and it was not propagated by calcium induced calcium release. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Monitoring Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes with Genetically Encoded Calcium and Voltage Fluorescent Reporters

    Rami Shinnawi

    2015-10-01

    Full Text Available The advent of the human-induced pluripotent stem cell (hiPSC technology has transformed biomedical research, providing new tools for human disease modeling, drug development, and regenerative medicine. To fulfill its unique potential in the cardiovascular field, efficient methods should be developed for high-resolution, large-scale, long-term, and serial functional cellular phenotyping of hiPSC-derived cardiomyocytes (hiPSC-CMs. To achieve this goal, we combined the hiPSC technology with genetically encoded voltage (ArcLight and calcium (GCaMP5G fluorescent indicators. Expression of ArcLight and GCaMP5G in hiPSC-CMs permitted to reliably follow changes in transmembrane potential and intracellular calcium levels, respectively. This allowed monitoring short- and long-term changes in action-potential and calcium-handling properties and the development of arrhythmias in response to several pharmaceutical agents and in hiPSC-CMs derived from patients with different inherited arrhythmogenic syndromes. Combining genetically encoded fluorescent reporters with hiPSC-CMs may bring a unique value to the study of inherited disorders, developmental biology, and drug development and testing.

  7. Dual Optical Recordings for Action Potentials and Calcium Handling in Induced Pluripotent Stem Cell Models of Cardiac Arrhythmias Using Genetically Encoded Fluorescent Indicators

    Song, LouJin; Awari, Daniel W.; Han, Elizabeth Y.; Uche-Anya, Eugenia; Park, Seon-Hye E.; Yabe, Yoko A.; Chung, Wendy K.

    2015-01-01

    Reprogramming of human somatic cells to pluripotency has been used to investigate disease mechanisms and to identify potential therapeutics. However, the methods used for reprogramming, in vitro differentiation, and phenotyping are still complicated, expensive, and time-consuming. To address the limitations, we first optimized a protocol for reprogramming of human fibroblasts and keratinocytes into pluripotency using single lipofection and the episomal vectors in a 24-well plate format. This method allowed us to generate multiple lines of integration-free and feeder-free induced pluripotent stem cells (iPSCs) from seven patients with cardiac diseases and three controls. Second, we differentiated human iPSCs derived from patients with Timothy syndrome into cardiomyocytes using a monolayer differentiation method. We found that Timothy syndrome cardiomyocytes showed slower, irregular contractions and abnormal calcium handling compared with the controls. The results are consistent with previous reports using a retroviral method for reprogramming and an embryoid body-based method for cardiac differentiation. Third, we developed an efficient approach for recording the action potentials and calcium transients simultaneously in control and patient cardiomyocytes using genetically encoded fluorescent indicators, ArcLight and R-GECO1. The dual optical recordings enabled us to observe prolonged action potentials and abnormal calcium handling in Timothy syndrome cardiomyocytes. We confirmed that roscovitine rescued the phenotypes in Timothy syndrome cardiomyocytes and that these findings were consistent with previous studies using conventional electrophysiological recordings and calcium imaging with dyes. The approaches using our optimized methods and dual optical recordings will improve iPSC applicability for disease modeling to investigate mechanisms underlying cardiac arrhythmias and to test potential therapeutics. PMID:25769651

  8. Calcium imaging with genetically encoded sensor Case12: Facile analysis of α7/α9 nAChR mutants.

    Irina Shelukhina

    Full Text Available Elucidation of the structural basis of pharmacological differences for highly homologous α7 and α9 nicotinic acetylcholine receptors (nAChRs may shed light on their involvement in different physiological functions and diseases. Combination of site-directed mutagenesis and electrophysiology is a powerful tool to pinpoint the key amino-acid residues in the receptor ligand-binding site, but for α7 and α9 nAChRs it is complicated by their poor expression and fast desensitization. Here, we probed the ligand-binding properties of α7/α9 nAChR mutants by a proposed simple and fast calcium imaging method. The method is based on transient co-expression of α7/α9 nAChR mutants in neuroblastoma cells together with Ric-3 or NACHO chaperones and Case12 fluorescent calcium ion sensor followed by analysis of their pharmacology using a fluorescence microscope or a fluorometric imaging plate reader (FLIPR with a GFP filter set. The results obtained were confirmed by electrophysiology and by calcium imaging with the conventional calcium indicator Fluo-4. The affinities for acetylcholine and epibatidine were determined for human and rat α7 nAChRs, and for their mutants with homologous residues of α9 nAChR incorporated at positions 117-119, 184, 185, 187, and 189, which are anticipated to be involved in ligand binding. The strongest decrease in the affinity was observed for mutations at positions 187 and 119. The L119D mutation of α7 nAChR, showing a larger effect for epibatidine than for acetylcholine, may implicate this position in pharmacological differences between α7 and α9 nAChRs.

  9. Optical recording of neuronal activity with a genetically-encoded calcium indicator in anesthetized and freely moving mice

    Henry Lütcke

    2010-04-01

    Full Text Available Fluorescent calcium (Ca2+ indicator proteins (FCIPs are promising tools for functional imaging of cellular activity in living animals. However, they have still not reached their full potential for in vivo imaging of neuronal activity due to limitations in expression levels, dynamic range, and sensitivity for reporting action potentials. Here, we report that viral expression of the ratiometric Ca2+ sensor yellow cameleon 3.60 (YC3.60 in pyramidal neurons of mouse barrel cortex enables in vivo measurement of neuronal activity with high dynamic range and sensitivity across multiple spatial scales. By combining juxtacellular recordings and two-photon imaging in vitro and in vivo, we demonstrate that YC3.60 can resolve single action potential (AP-evoked Ca2+ transients and reliably reports bursts of APs with negligible saturation. Spontaneous and whisker-evoked Ca2+ transients were detected in individual apical dendrites and somata as well as in local neuronal populations. Moreover, bulk measurements using wide-field imaging or fiber-optics revealed sensory-evoked YC3.60 signals in large areas of the barrel field. Fiber-optic recordings in particular enabled measurements in awake, freely moving mice and revealed complex Ca2+ dynamics, possibly reflecting different behavior-related brain states. Viral expression of YC3.60 - in combination with various optical techniques - thus opens a multitude of opportunities for functional studies of the neural basis of animal behavior, from dendrites to the levels of local and large-scale neuronal populations.

  10. Probabilistic encoding of stimulus strength in astrocyte global calcium signals.

    Croft, Wayne; Reusch, Katharina; Tilunaite, Agne; Russell, Noah A; Thul, Rüdiger; Bellamy, Tomas C

    2016-04-01

    Astrocyte calcium signals can range in size from subcellular microdomains to waves that spread through the whole cell (and into connected cells). The differential roles of such local or global calcium signaling are under intense investigation, but the mechanisms by which local signals evolve into global signals in astrocytes are not well understood, nor are the computational rules by which physiological stimuli are transduced into a global signal. To investigate these questions, we transiently applied receptor agonists linked to calcium signaling to primary cultures of cerebellar astrocytes. Astrocytes repetitively tested with the same stimulus responded with global signals intermittently, indicating that each stimulus had a defined probability for triggering a response. The response probability varied between agonists, increased with agonist concentration, and could be positively and negatively modulated by crosstalk with other signaling pathways. To better understand the processes determining the evolution of a global signal, we recorded subcellular calcium "puffs" throughout the whole cell during stimulation. The key requirement for puffs to trigger a global calcium wave following receptor activation appeared to be the synchronous release of calcium from three or more sites, rather than an increasing calcium load accumulating in the cytosol due to increased puff size, amplitude, or frequency. These results suggest that the concentration of transient stimuli will be encoded into a probability of generating a global calcium response, determined by the likelihood of synchronous release from multiple subcellular sites. © 2015 Wiley Periodicals, Inc.

  11. Extraordinarily Adaptive Properties of the Genetically Encoded Amino Acids

    Ilardo, Melissa; Meringer, Markus; Freeland, Stephen; Rasulev, Bakhtiyor; Cleaves II, H. James

    2015-01-01

    Using novel advances in computational chemistry, we demonstrate that the set of 20 genetically encoded amino acids, used nearly universally to construct all coded terrestrial proteins, has been highly influenced by natural selection. We defined an adaptive set of amino acids as one whose members thoroughly cover relevant physico-chemical properties, or “chemistry space.” Using this metric, we compared the encoded amino acid alphabet to random sets of amino acids. These random sets were drawn from a computationally generated compound library containing 1913 alternative amino acids that lie within the molecular weight range of the encoded amino acids. Sets that cover chemistry space better than the genetically encoded alphabet are extremely rare and energetically costly. Further analysis of more adaptive sets reveals common features and anomalies, and we explore their implications for synthetic biology. We present these computations as evidence that the set of 20 amino acids found within the standard genetic code is the result of considerable natural selection. The amino acids used for constructing coded proteins may represent a largely global optimum, such that any aqueous biochemistry would use a very similar set. PMID:25802223

  12. Extraordinarily adaptive properties of the genetically encoded amino acids.

    Ilardo, Melissa; Meringer, Markus; Freeland, Stephen; Rasulev, Bakhtiyor; Cleaves, H James

    2015-03-24

    Using novel advances in computational chemistry, we demonstrate that the set of 20 genetically encoded amino acids, used nearly universally to construct all coded terrestrial proteins, has been highly influenced by natural selection. We defined an adaptive set of amino acids as one whose members thoroughly cover relevant physico-chemical properties, or "chemistry space." Using this metric, we compared the encoded amino acid alphabet to random sets of amino acids. These random sets were drawn from a computationally generated compound library containing 1913 alternative amino acids that lie within the molecular weight range of the encoded amino acids. Sets that cover chemistry space better than the genetically encoded alphabet are extremely rare and energetically costly. Further analysis of more adaptive sets reveals common features and anomalies, and we explore their implications for synthetic biology. We present these computations as evidence that the set of 20 amino acids found within the standard genetic code is the result of considerable natural selection. The amino acids used for constructing coded proteins may represent a largely global optimum, such that any aqueous biochemistry would use a very similar set.

  13. Imaging dynamic redox processes with genetically encoded probes.

    Ezeriņa, Daria; Morgan, Bruce; Dick, Tobias P

    2014-08-01

    Redox signalling plays an important role in many aspects of physiology, including that of the cardiovascular system. Perturbed redox regulation has been associated with numerous pathological conditions; nevertheless, the causal relationships between redox changes and pathology often remain unclear. Redox signalling involves the production of specific redox species at specific times in specific locations. However, until recently, the study of these processes has been impeded by a lack of appropriate tools and methodologies that afford the necessary redox species specificity and spatiotemporal resolution. Recently developed genetically encoded fluorescent redox probes now allow dynamic real-time measurements, of defined redox species, with subcellular compartment resolution, in intact living cells. Here we discuss the available genetically encoded redox probes in terms of their sensitivity and specificity and highlight where uncertainties or controversies currently exist. Furthermore, we outline major goals for future probe development and describe how progress in imaging methodologies will improve our ability to employ genetically encoded redox probes in a wide range of situations. This article is part of a special issue entitled "Redox Signalling in the Cardiovascular System." Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Design and development of genetically encoded fluorescent sensors to monitor intracellular chemical and physical parameters.

    Germond, Arno; Fujita, Hideaki; Ichimura, Taro; Watanabe, Tomonobu M

    2016-06-01

    Over the past decades many researchers have made major contributions towards the development of genetically encoded (GE) fluorescent sensors derived from fluorescent proteins. GE sensors are now used to study biological phenomena by facilitating the measurement of biochemical behaviors at various scales, ranging from single molecules to single cells or even whole animals. Here, we review the historical development of GE fluorescent sensors and report on their current status. We specifically focus on the development strategies of the GE sensors used for measuring pH, ion concentrations (e.g., chloride and calcium), redox indicators, membrane potential, temperature, pressure, and molecular crowding. We demonstrate that these fluroescent protein-based sensors have a shared history of concepts and development strategies, and we highlight the most original concepts used to date. We believe that the understanding and application of these various concepts will pave the road for the development of future GE sensors and lead to new breakthroughs in bioimaging.

  15. Genetically encoded probes for NAD+/NADH monitoring.

    Bilan, Dmitry S; Belousov, Vsevolod V

    2016-11-01

    NAD + and NADH participate in many metabolic reactions. The NAD + /NADH ratio is an important parameter reflecting the general metabolic and redox state of different types of cells. For a long time, in situ and in vivo NAD + /NADH monitoring has been hampered by the lack of suitable tools. The recent development of genetically encoded indicators based on fluorescent proteins linked to specific nucleotide-binding domains has already helped to address this monitoring problem. In this review, we will focus on four available indicators: Peredox, Frex family probes, RexYFP and SoNar. Each indicator has advantages and limitations. We will also discuss the most important points that should be considered when selecting a suitable indicator for certain experimental conditions. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Monitoring thioredoxin redox with a genetically encoded red fluorescent biosensor.

    Fan, Yichong; Makar, Merna; Wang, Michael X; Ai, Hui-Wang

    2017-09-01

    Thioredoxin (Trx) is one of the two major thiol antioxidants, playing essential roles in redox homeostasis and signaling. Despite its importance, there is a lack of methods for monitoring Trx redox dynamics in live cells, hindering a better understanding of physiological and pathological roles of the Trx redox system. In this work, we developed the first genetically encoded fluorescent biosensor for Trx redox by engineering a redox relay between the active-site cysteines of human Trx1 and rxRFP1, a redox-sensitive red fluorescent protein. We used the resultant biosensor-TrxRFP1-to selectively monitor perturbations of Trx redox in various mammalian cell lines. We subcellularly localized TrxRFP1 to image compartmentalized Trx redox changes. We further combined TrxRFP1 with a green fluorescent Grx1-roGFP2 biosensor to simultaneously monitor Trx and glutathione redox dynamics in live cells in response to chemical and physiologically relevant stimuli.

  17. Cyclic Concatenated Genetic Encoder: A mathematical proposal for biological inferences.

    Duarte-González, M E; Echeverri, O Y; Guevara, J M; Palazzo, R

    2018-01-01

    The organization of the genetic information and its ability to be conserved and translated to proteins with low error rates have been the subject of study by scientists from different disciplines. Recently, it has been proposed that living organisms display an intra-cellular transmission system of genetic information, similar to a model of digital communication system, in which there is the ability to detect and correct errors. In this work, the concept of Concatenated Genetic Encoder is introduced and applied to the analysis of protein sequences as a tool for exploring evolutionary relationships. For such purposes Error Correcting Codes (ECCs) are used to represent proteins. A methodology for representing or identifying proteins by use of BCH codes over ℤ 20 and F 4 ×ℤ 5 is proposed and cytochrome b6-f complex subunit 6-OS sequences, corresponding to different plants species, are analyzed according to the proposed methodology and results are contrasted to phylogenetic and taxonomic analyses. Through the analyses, it was observed that using BCH codes only some sequences are identified, all of which differ in one amino acid from the original sequence. In addition, mathematical relationships among identified sequences are established by considering minimal polynomials, where such sequences showed a close relationship as revealed in the phylogenetic reconstruction. Results, here shown, point out that communication theory may provide biology of interesting and useful tools to identify biological relationships among proteins, however the proposed methodology needs to be improved and rigorously tested in order to become into an applicable tool for biological analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Transfection of genetically encoded photoswitchable probes for STORM imaging.

    Bates, Mark; Jones, Sara A; Zhuang, Xiaowei

    2013-06-01

    Conventional fluorescence microscopy is limited by its spatial resolution, leaving many biological structures too small to be studied in detail. Stochastic optical reconstruction microscopy (STORM) is a method for superresolution fluorescence imaging based on the high accuracy localization of individual fluorophores. It uses optically switchable fluorophores: molecules that can be switched between a nonfluorescent and a fluorescent state by exposure to light. This protocol describes the transfection of genetically encoded photoswitchable probes for STORM imaging. It includes a discussion of how to choose a photoswitchable fluorescent protein; standard molecular biology techniques should be used to generate a plasmid containing the sequence of the photoswitchable protein linked to the gene of interest. Once the plasmid has been generated and has been verified, it can be introduced into cells via any standard means of gene delivery, such as lipofection or electroporation. Optimal conditions will vary considerably for different cell lines and plasmids. Here, we present an example protocol for the transfection of BS-C-1 cells with an mEos2-vimentin plasmid using the lipid-based reagent FuGENE6.

  19. Characterizing ligand-gated ion channel receptors with genetically encoded Ca2++ sensors.

    John G Yamauchi

    2011-01-01

    Full Text Available We present a cell based system and experimental approach to characterize agonist and antagonist selectivity for ligand-gated ion channels (LGIC by developing sensor cells stably expressing a Ca(2+ permeable LGIC and a genetically encoded Förster (or fluorescence resonance energy transfer (FRET-based calcium sensor. In particular, we describe separate lines with human α7 and human α4β2 nicotinic acetylcholine receptors, mouse 5-HT(3A serotonin receptors and a chimera of human α7/mouse 5-HT(3A receptors. Complete concentration-response curves for agonists and Schild plots of antagonists were generated from these sensors and the results validate known pharmacology of the receptors tested. Concentration-response relations can be generated from either the initial rate or maximal amplitudes of FRET-signal. Although assaying at a medium throughput level, this pharmacological fluorescence detection technique employs a clonal line for stability and has versatility for screening laboratory generated congeners as agonists or antagonists on multiple subtypes of ligand-gated ion channels. The clonal sensor lines are also compatible with in vivo usage to measure indirectly receptor activation by endogenous neurotransmitters.

  20. Nonlinear inversion of potential-field data using a hybrid-encoding genetic algorithm

    Chen, C.; Xia, J.; Liu, J.; Feng, G.

    2006-01-01

    Using a genetic algorithm to solve an inverse problem of complex nonlinear geophysical equations is advantageous because it does not require computer gradients of models or "good" initial models. The multi-point search of a genetic algorithm makes it easier to find the globally optimal solution while avoiding falling into a local extremum. As is the case in other optimization approaches, the search efficiency for a genetic algorithm is vital in finding desired solutions successfully in a multi-dimensional model space. A binary-encoding genetic algorithm is hardly ever used to resolve an optimization problem such as a simple geophysical inversion with only three unknowns. The encoding mechanism, genetic operators, and population size of the genetic algorithm greatly affect search processes in the evolution. It is clear that improved operators and proper population size promote the convergence. Nevertheless, not all genetic operations perform perfectly while searching under either a uniform binary or a decimal encoding system. With the binary encoding mechanism, the crossover scheme may produce more new individuals than with the decimal encoding. On the other hand, the mutation scheme in a decimal encoding system will create new genes larger in scope than those in the binary encoding. This paper discusses approaches of exploiting the search potential of genetic operations in the two encoding systems and presents an approach with a hybrid-encoding mechanism, multi-point crossover, and dynamic population size for geophysical inversion. We present a method that is based on the routine in which the mutation operation is conducted in the decimal code and multi-point crossover operation in the binary code. The mix-encoding algorithm is called the hybrid-encoding genetic algorithm (HEGA). HEGA provides better genes with a higher probability by a mutation operator and improves genetic algorithms in resolving complicated geophysical inverse problems. Another significant

  1. A genetically encoded biosensor for visualising hypoxia responses in vivo

    Tvisha Misra

    2017-02-01

    Full Text Available Cells experience different oxygen concentrations depending on location, organismal developmental stage, and physiological or pathological conditions. Responses to reduced oxygen levels (hypoxia rely on the conserved hypoxia-inducible factor 1 (HIF-1. Understanding the developmental and tissue-specific responses to changing oxygen levels has been limited by the lack of adequate tools for monitoring HIF-1 in vivo. To visualise and analyse HIF-1 dynamics in Drosophila, we used a hypoxia biosensor consisting of GFP fused to the oxygen-dependent degradation domain (ODD of the HIF-1 homologue Sima. GFP-ODD responds to changing oxygen levels and to genetic manipulations of the hypoxia pathway, reflecting oxygen-dependent regulation of HIF-1 at the single-cell level. Ratiometric imaging of GFP-ODD and a red-fluorescent reference protein reveals tissue-specific differences in the cellular hypoxic status at ambient normoxia. Strikingly, cells in the larval brain show distinct hypoxic states that correlate with the distribution and relative densities of respiratory tubes. We present a set of genetic and image analysis tools that enable new approaches to map hypoxic microenvironments, to probe effects of perturbations on hypoxic signalling, and to identify new regulators of the hypoxia response.

  2. Association of Genetic Variants Related to Serum Calcium Levels With Coronary Artery Disease and Myocardial Infarction.

    Larsson, Susanna C; Burgess, Stephen; Michaëlsson, Karl

    2017-07-25

    Serum calcium has been associated with cardiovascular disease in observational studies and evidence from randomized clinical trials indicates that calcium supplementation, which raises serum calcium levels, may increase the risk of cardiovascular events, particularly myocardial infarction. To evaluate the potential causal association between genetic variants related to elevated serum calcium levels and risk of coronary artery disease (CAD) and myocardial infarction using mendelian randomization. The analyses were performed using summary statistics obtained for single-nucleotide polymorphisms (SNPs) identified from a genome-wide association meta-analysis of serum calcium levels (N = up to 61 079 individuals) and from the Coronary Artery Disease Genome-wide Replication and Meta-analysis Plus the Coronary Artery Disease Genetics (CardiogramplusC4D) consortium's 1000 genomes-based genome-wide association meta-analysis (N = up to 184 305 individuals) that included cases (individuals with CAD and myocardial infarction) and noncases, with baseline data collected from 1948 and populations derived from across the globe. The association of each SNP with CAD and myocardial infarction was weighted by its association with serum calcium, and estimates were combined using an inverse-variance weighted meta-analysis. Genetic risk score based on genetic variants related to elevated serum calcium levels. Co-primary outcomes were the odds of CAD and myocardial infarction. Among the mendelian randomized analytic sample of 184 305 individuals (60 801 CAD cases [approximately 70% with myocardial infarction] and 123 504 noncases), the 6 SNPs related to serum calcium levels and without pleiotropic associations with potential confounders were estimated to explain about 0.8% of the variation in serum calcium levels. In the inverse-variance weighted meta-analysis (combining the estimates of the 6 SNPs), the odds ratios per 0.5-mg/dL increase (about 1 SD) in genetically

  3. Chemical fingerprints encode mother–offspring similarity, colony membership, relatedness, and genetic quality in fur seals

    Stoffel, Martin A.; Caspers, Barbara A.; Forcada, Jaume; Giannakara, Athina; Baier, Markus; Eberhart-Phillips, Luke; Müller, Caroline; Hoffman, Joseph I.

    2015-01-01

    Chemical communication underpins virtually all aspects of vertebrate social life, yet remains poorly understood because of its highly complex mechanistic basis. We therefore used chemical fingerprinting of skin swabs and genetic analysis to explore the chemical cues that may underlie mother–offspring recognition in colonially breeding Antarctic fur seals. By sampling mother–offspring pairs from two different colonies, using a variety of statistical approaches and genotyping a large panel of microsatellite loci, we show that colony membership, mother–offspring similarity, heterozygosity, and genetic relatedness are all chemically encoded. Moreover, chemical similarity between mothers and offspring reflects a combination of genetic and environmental influences, the former partly encoded by substances resembling known pheromones. Our findings reveal the diversity of information contained within chemical fingerprints and have implications for understanding mother–offspring communication, kin recognition, and mate choice. PMID:26261311

  4. Calcium

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  5. Regulating Intracellular Calcium in Plants: From Molecular Genetics to Physiology

    Sze, Heven

    2008-01-01

    To grow, develop, adapt, and reproduce, plants have evolved mechanisms to regulate the uptake, translocation and sorting of calcium ions into different cells and subcellular compartments. Yet how plants accomplish this remarkable feat is still poorly understood. The spatial and temporal changes in intracellular (Ca2+) during growth and during responses to hormonal and environmental stimuli indicate that Ca2+ influx and efflux transporters are diverse and tightly regulated in plants. The specific goals were to determine the biological roles of multiple Ca pumps (ECAs) in the model plant Arabidopsis thaliana. We had pioneered the use of K616 yeast strain to functionally express plant Ca pumps, and demonstrated two distinct types of Ca pumps in plants (Sze et al., 2000. Annu Rev Plant Biol. 51,433). ACA2 represented one type that was auto-inhibited by the N-terminal region and stimulated by calmodulin. ECA1 represented another type that was not sensitive to calmodulin and phylogenetically distinct from ACAs. The goal to determine the biological roles of multiple ECA-type Ca pumps in Arabidopsis has been accomplished. Although we demonstrated ECA1 was a Ca pump by functional expression in yeast, the in vivo roles of ECAs was unclear. A few highlights are described. ECA1 and/or ECA4 are Ca/Mn pumps localized to the ER and are highly expressed in all cell types. Using homozygous T-DNA insertional mutants of eca1, we demonstrated that the ER-bound ECA1 supports growth and confers tolerance of plants growing on medium low in Ca or containing toxic levels of Mn. This is the first genetic study to determine the in vivo function of a Ca pump in plants. A phylogenetically distinct ECA3 is also a Ca/Mn pump that is localized to endosome, such as post-Golgi compartments. Although it is expressed at lower levels than ECA1, eca3 mutants are impaired in Ca-dependent root growth and in pollen tube elongation. Increased secretion of wall proteins in mutants suggests that Ca and Mn

  6. The pmr gene, encoding a Ca2+-ATPase, is required for calcium and manganese homeostasis and normal development of hyphae and conidia in Neurospora crassa.

    Bowman, Barry J; Abreu, Stephen; Johl, Jessica K; Bowman, Emma Jean

    2012-11-01

    The pmr gene is predicted to encode a Ca(2+)-ATPase in the secretory pathway. We examined two strains of Neurospora crassa that lacked PMR: the Δpmr strain, in which pmr was completely deleted, and pmr(RIP), in which the gene was extensively mutated. Both strains had identical, complex phenotypes. Compared to the wild type, these strains required high concentrations of calcium or manganese for optimal growth and had highly branched, slow-growing hyphae. They conidiated poorly, and the shape and size of the conidia were abnormal. Calcium accumulated in the Δpmr strains to only 20% of the wild-type level. High concentrations of MnCl(2) (1 to 5 mM) in growth medium partially suppressed the morphological defects but did not alter the defect in calcium accumulation. The Δpmr Δnca-2 double mutant (nca-2 encodes a Ca(2+)-ATPase in the plasma membrane) accumulated 8-fold more calcium than the wild type, and the morphology of the hyphae was more similar to that of wild-type hyphae. Previous experiments failed to show a function for nca-1, which encodes a SERCA-type Ca(2+)-ATPase in the endoplasmic reticulum (B. J. Bowman, S. Abreu, E. Margolles-Clark, M. Draskovic, and E. J. Bowman, Eukaryot. Cell 10:654-661, 2011). The pmr(RIP) Δnca-1 double mutant accumulated small amounts of calcium, like the Δpmr strain, but exhibited even more extreme morphological defects. Thus, PMR can apparently replace NCA-1 in the endoplasmic reticulum, but NCA-1 cannot replace PMR. The morphological defects in the Δpmr strain are likely caused, in part, by insufficient concentrations of calcium and manganese in the Golgi compartment; however, PMR is also needed to accumulate normal levels of calcium in the whole cell.

  7. Functional, genetic and bioinformatic characterization of a calcium/calmodulin kinase gene in Sporothrix schenckii

    Rodriguez-del Valle Nuri

    2007-11-01

    Full Text Available Abstract Background Sporothrix schenckii is a pathogenic, dimorphic fungus, the etiological agent of sporotrichosis, a subcutaneous lymphatic mycosis. Dimorphism in S. schenckii responds to second messengers such as cAMP and calcium, suggesting the possible involvement of a calcium/calmodulin kinase in its regulation. In this study we describe a novel calcium/calmodulin-dependent protein kinase gene in S. schenckii, sscmk1, and the effects of inhibitors of calmodulin and calcium/calmodulin kinases on the yeast to mycelium transition and the yeast cell cycle. Results Using the PCR homology approach a new member of the calcium/calmodulin kinase family, SSCMK1, was identified in this fungus. The cDNA sequence of sscmk1 revealed an open reading frame of 1,221 nucleotides encoding a 407 amino acid protein with a predicted molecular weight of 45.6 kDa. The genomic sequence of sscmk1 revealed the same ORF interrupted by five introns. Bioinformatic analyses of SSCMK1 showed that this protein had the distinctive features that characterize a calcium/calmodulin protein kinase: a serine/threonine protein kinase domain and a calmodulin-binding domain. When compared to homologues from seven species of filamentous fungi, SSCMK1 showed substantial similarities, except for a large and highly variable region that encompasses positions 330 – 380 of the multiple sequence alignment. Inhibition studies using calmodulin inhibitor W-7, and calcium/calmodulin kinase inhibitors, KN-62 and lavendustin C, were found to inhibit budding by cells induced to re-enter the yeast cell cycle and to favor the yeast to mycelium transition. Conclusion This study constitutes the first evidence of the presence of a calcium/calmodulin kinase-encoding gene in S. schenckii and its possible involvement as an effector of dimorphism in this fungus. These results suggest that a calcium/calmodulin dependent signaling pathway could be involved in the regulation of dimorphism in this fungus

  8. StrigoQuant: A genetically encoded biosensor for quantifying strigolactone activity and specificity

    Samodelov, S. L.

    2016-11-05

    Strigolactones are key regulators of plant development and interaction with symbiotic fungi; however, quantitative tools for strigolactone signaling analysis are lacking. We introduce a genetically encoded hormone biosensor used to analyze strigolactone-mediated processes, including the study of the components involved in the hormone perception/signaling complex and the structural specificity and sensitivity of natural and synthetic strigolactones in Arabidopsis, providing quantitative insights into the stereoselectivity of strigolactone perception. Given the high specificity, sensitivity, dynamic range of activity, modular construction, ease of implementation, and wide applicability, the biosensor StrigoQuant will be useful in unraveling multiple levels of strigolactone metabolic and signaling networks.

  9. pHlash: a new genetically encoded and ratiometric luminescence sensor of intracellular pH.

    Zhang, Yunfei; Xie, Qiguang; Robertson, J Brian; Johnson, Carl Hirschie

    2012-01-01

    We report the development of a genetically encodable and ratiometic pH probe named "pHlash" that utilizes Bioluminescence Resonance Energy Transfer (BRET) rather than fluorescence excitation. The pHlash sensor-composed of a donor luciferase that is genetically fused to a Venus fluorophore-exhibits pH dependence of its spectral emission in vitro. When expressed in either yeast or mammalian cells, pHlash reports basal pH and cytosolic acidification in vivo. Its spectral ratio response is H(+) specific; neither Ca(++), Mg(++), Na(+), nor K(+) changes the spectral form of its luminescence emission. Moreover, it can be used to image pH in single cells. This is the first BRET-based sensor of H(+) ions, and it should allow the approximation of pH in cytosolic and organellar compartments in applications where current pH probes are inadequate.

  10. pHlash: a new genetically encoded and ratiometric luminescence sensor of intracellular pH.

    Yunfei Zhang

    Full Text Available We report the development of a genetically encodable and ratiometic pH probe named "pHlash" that utilizes Bioluminescence Resonance Energy Transfer (BRET rather than fluorescence excitation. The pHlash sensor-composed of a donor luciferase that is genetically fused to a Venus fluorophore-exhibits pH dependence of its spectral emission in vitro. When expressed in either yeast or mammalian cells, pHlash reports basal pH and cytosolic acidification in vivo. Its spectral ratio response is H(+ specific; neither Ca(++, Mg(++, Na(+, nor K(+ changes the spectral form of its luminescence emission. Moreover, it can be used to image pH in single cells. This is the first BRET-based sensor of H(+ ions, and it should allow the approximation of pH in cytosolic and organellar compartments in applications where current pH probes are inadequate.

  11. Genetic variants in nuclear-encoded mitochondrial genes influence AIDS progression.

    Sher L Hendrickson

    2010-09-01

    Full Text Available The human mitochondrial genome includes only 13 coding genes while nuclear-encoded genes account for 99% of proteins responsible for mitochondrial morphology, redox regulation, and energetics. Mitochondrial pathogenesis occurs in HIV patients and genetically, mitochondrial DNA haplogroups with presumed functional differences have been associated with differential AIDS progression.Here we explore whether single nucleotide polymorphisms (SNPs within 904 of the estimated 1,500 genes that specify nuclear-encoded mitochondrial proteins (NEMPs influence AIDS progression among HIV-1 infected patients. We examined NEMPs for association with the rate of AIDS progression using genotypes generated by an Affymetrix 6.0 genotyping array of 1,455 European American patients from five US AIDS cohorts. Successfully genotyped SNPs gave 50% or better haplotype coverage for 679 of known NEMP genes. With a Bonferroni adjustment for the number of genes and tests examined, multiple SNPs within two NEMP genes showed significant association with AIDS progression: acyl-CoA synthetase medium-chain family member 4 (ACSM4 on chromosome 12 and peroxisomal D3,D2-enoyl-CoA isomerase (PECI on chromosome 6.Our previous studies on mitochondrial DNA showed that European haplogroups with presumed functional differences were associated with AIDS progression and HAART mediated adverse events. The modest influences of nuclear-encoded mitochondrial genes found in the current study add support to the idea that mitochondrial function plays a role in AIDS pathogenesis.

  12. Engineering a genetically-encoded SHG chromophore by electrostatic targeting to the membrane

    Yuka eJinno

    2014-11-01

    Full Text Available Although second harmonic generation (SHG microscopy provides unique imaging advantages for voltage imaging and other biological applications, genetically-encoded SHG chromophores remain relatively unexplored. SHG only arises from non-centrosymmetric media, so an anisotropic arrangement of chromophores is essential to provide strong SHG signals. Here, inspired by the mechanism by which K-Ras4B associates with plasma membranes, we sought to achieve asymmetric arrangements of chromophores at the membrane-cytoplasm interface using the fluorescent protein mVenus. After adding a farnesylation motif to the C-terminus of mVenus, nine amino acids composing its -barrel surface were replaced by lysine, forming an electrostatic patch. This protein (mVe9Knus-CVIM was efficiently targeted to the plasma membrane in a geometrically defined manner and exhibited SHG in HEK293 cells. In agreement with its design, mVe9Knus-CVIM hyperpolarizability was oriented at a small angle (~7.3º from the membrane normal. Genetically-encoded SHG chromophores could serve as a molecular platform for imaging membrane potential.

  13. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons

    Joseph Valentino Raimondo

    2012-05-01

    Full Text Available The regulation of hydrogen ion concentration (pH is fundamental to cell viability, metabolism and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilised to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E2GFP and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  14. Genetically encoded proton sensors reveal activity-dependent pH changes in neurons.

    Raimondo, Joseph V; Irkle, Agnese; Wefelmeyer, Winnie; Newey, Sarah E; Akerman, Colin J

    2012-01-01

    The regulation of hydrogen ion concentration (pH) is fundamental to cell viability, metabolism, and enzymatic function. Within the nervous system, the control of pH is also involved in diverse and dynamic processes including development, synaptic transmission, and the control of network excitability. As pH affects neuronal activity, and can also itself be altered by neuronal activity, the existence of tools to accurately measure hydrogen ion fluctuations is important for understanding the role pH plays under physiological and pathological conditions. Outside of their use as a marker of synaptic release, genetically encoded pH sensors have not been utilized to study hydrogen ion fluxes associated with network activity. By combining whole-cell patch clamp with simultaneous two-photon or confocal imaging, we quantified the amplitude and time course of neuronal, intracellular, acidic transients evoked by epileptiform activity in two separate in vitro models of temporal lobe epilepsy. In doing so, we demonstrate the suitability of three genetically encoded pH sensors: deGFP4, E(2)GFP, and Cl-sensor for investigating activity-dependent pH changes at the level of single neurons.

  15. Inter-population differences in otolith morphology are genetically encoded in the killifish Aphanius fasciatus (Cyprinodontiformes

    Ali Annabi

    2013-06-01

    Full Text Available Inter-population differences in otolith shape, morphology and chemistry have been used effectively as indicators for stock assessment or for recognizing environmental adaptation in fishes. However, the precise parameters that affect otolith morphology remain incompletely understood. Here we provide the first direct support for the hypothesis that inter-population differences in otolith morphology are genetically encoded. The study is based on otolith morphology and two mitochondrial markers (D-loop, 16S rRNA of three natural populations of Aphanius fasciatus (Teleostei: Cyprinodontidae from Southeast Tunisia. Otolith and genetic data yielded congruent tree topologies. Divergence of populations likely results from isolation events in the course of the Pleistocene sea level drops. We propose that otolith morphology is a valuable tool for resolving genetic diversity also within other teleost species, which may be important for ecosystem management and conservation of genetic diversity. As reconstructions of ancient teleost fish faunas are often solely based on fossil otoliths, our discoveries may also lead to a new approach to research in palaeontology.

  16. Genetic analysis of the VP2-encoding gene of canine parvovirus strains from Africa.

    Dogonyaro, Banenat B; Bosman, Anna-Mari; Sibeko, Kgomotso P; Venter, Estelle H; van Vuuren, Moritz

    2013-08-30

    Since the emergence of canine parvovirus type-2 (CPV-2) in the early 1970s, it has been evolving into novel genetic and antigenic variants (CPV-2a, 2b and 2c) that are unevenly distributed throughout the world. Genetic characterization of CPV-2 has not been documented in Africa since 1998 apart from the study carried out in Tunisia 2009. A total of 139 field samples were collected from South Africa and Nigeria, detected using PCR and the full length VP2-encoding gene of 27 positive samples were sequenced and genetically analyzed. Nigerian samples (n=6), South Africa (n=19) and vaccine strains (n=2) were compared with existing sequences obtained from GenBank. The results showed the presence of both CPV-2a and 2b in South Africa and only CPV-2a in Nigeria. No CPV-2c strain was detected during this study. Phylogenetic analysis showed a clustering not strictly associated with the geographical origin of the analyzed strains, although most of the South African strains tended to cluster together and the viral strains analyzed in this study were not completely distinct from CPV-2 strains from other parts of the world. Amino acid analysis showed predicted amino acid changes. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. Developing a Genetically Encoded, Cross-Species Biosensor for Detecting Ammonium and Regulating Biosynthesis of Cyanophycin.

    Xiao, Yi; Jiang, Wen; Zhang, Fuzhong

    2017-10-20

    Responding to nitrogen status is essential for all living organisms. Bacteria have evolved various complex and exquisite regulatory systems to control nitrogen metabolism. However, natural nitrogen regulatory systems, owing to their complexity, often function only in their original hosts and do not respond properly when transferred to another species. By harnessing the Lactococcus GlnRA system, we developed a genetically encoded, cross-species ammonium biosensor that displays a dynamic range up to 9-fold upon detection of ammonium ion. We demonstrated applications of this ammonium biosensor in three different species (Escherichia coli, Pseudomonas putida, and Synechocystis sp.) to detect different nitrogen sources. This ammonium sensor was further used to regulate the biosynthesis of a nitrogen-rich polymer, cyanophycin, based on ammonium concentration. Given the importance of nitrogen responses, the developed biosensor should be broadly applicable to synthetic biology and bioengineering.

  18. The study of hydrogen peroxide level under cisplatin action using genetically encoded sensor hyper

    Belova, A. S.; Orlova, A. G.; Maslennikova, A. V.; Brilkina, A. A.; Balalaeva, I. V.; Antonova, N. O.; Mishina, N. M.; Shakhova, N. M.; Belousov, V. V.

    2014-03-01

    The aim of the work was to study the participation of hydrogen peroxide in reaction of cervical cancer cell line HeLa Kyoto on cisplatin action. Determination of hydrogen peroxide level was performed using genetically encoded fluorescent sensor HyPer2. The dependence of cell viability on cisplatin concentration was determined using MTT assay. Mechanisms of cell death as well as HyPer2 reaction was revealed by flow cytometry after 6-hours of incubation with cisplatin in different concentrations. Cisplatin used in low concentrations had no effect on hydrogen peroxide level in HeLa Kyoto cells. Increase of HyPer2 fluorescence was detected only after exposure with cisplatin in high concentration. The reaction was not the consequence of cell death.

  19. Interaction between genetic predisposition to obesity and dietary calcium in relation to subsequent change in body weight and waist circumference

    Larsen, Sofus C; Angquist, Lars; Ahluwalia, Tarun Veer Singh

    2014-01-01

    Studies indicate an effect of dietary calcium on change in body weight (BW) and waist circumference (WC), but the results are inconsistent. Furthermore, a relation could depend on genetic predisposition to obesity.......Studies indicate an effect of dietary calcium on change in body weight (BW) and waist circumference (WC), but the results are inconsistent. Furthermore, a relation could depend on genetic predisposition to obesity....

  20. Genetic and functional analysis of the gene encoding GAP-43 in schizophrenia.

    Shen, Yu-Chih; Tsai, Ho-Min; Cheng, Min-Chih; Hsu, Shih-Hsin; Chen, Shih-Fen; Chen, Chia-Hsiang

    2012-02-01

    In earlier reports, growth-associated protein 43 (GAP-43) has been shown to be critical for initial establishment or reorganization of synaptic connections, a process thought to be disrupted in schizophrenia. Additionally, abnormal GAP-43 expression in different brain regions has been linked to this disorder in postmortem brain studies. In this study, we investigated the involvement of the gene encoding GAP-43 in the susceptibility to schizophrenia. We searched for genetic variants in the promoter region and 3 exons (including both UTR ends) of the GAP-43 gene using direct sequencing in a sample of patients with schizophrenia (n=586) and non-psychotic controls (n=576), both being Han Chinese from Taiwan, and conducted an association and functional study. We identified 11 common polymorphisms in the GAP-43 gene. SNP and haplotype-based analyses displayed no associations with schizophrenia. Additionally, we identified 4 rare variants in 5 out of 586 patients, including 1 variant located at the promoter region (c.-258-4722G>T) and 1 synonymous (V110V) and 2 missense (G150R and P188L) variants located at exon 2. No rare variants were found in the control subjects. The results of the reporter gene assay demonstrated that the regulatory activity of construct containing c.-258-4722T was significantly lower as compared to the wild type construct (c.-258-4722G; panalysis also demonstrated the functional relevance of other rare variants. Our study lends support to the hypothesis of multiple rare mutations in schizophrenia, and it provides genetic clues that indicate the involvement of GAP-43 in this disorder. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Visualization of local Ca2+ dynamics with genetically encoded bioluminescent reporters.

    Rogers, Kelly L; Stinnakre, Jacques; Agulhon, Cendra; Jublot, Delphine; Shorte, Spencer L; Kremer, Eric J; Brûlet, Philippe

    2005-02-01

    Measurements of local Ca2+ signalling at different developmental stages and/or in specific cell types is important for understanding aspects of brain functioning. The use of light excitation in fluorescence imaging can cause phototoxicity, photobleaching and auto-fluorescence. In contrast, bioluminescence does not require the input of radiative energy and can therefore be measured over long periods, with very high temporal resolution. Aequorin is a genetically encoded Ca(2+)-sensitive bioluminescent protein, however, its low quantum yield prevents dynamic measurements of Ca2+ responses in single cells. To overcome this limitation, we recently reported the bi-functional Ca2+ reporter gene, GFP-aequorin (GA), which was developed specifically to improve the light output and stability of aequorin chimeras [V. Baubet, et al., (2000) PNAS, 97, 7260-7265]. In the current study, we have genetically targeted GA to different microdomains important in synaptic transmission, including to the mitochondrial matrix, endoplasmic reticulum, synaptic vesicles and to the postsynaptic density. We demonstrate that these reporters enable 'real-time' measurements of subcellular Ca2+ changes in single mammalian neurons using bioluminescence. The high signal-to-noise ratio of these reporters is also important in that it affords the visualization of Ca2+ dynamics in cell-cell communication in neuronal cultures and tissue slices. Further, we demonstrate the utility of this approach in ex-vivo preparations of mammalian retina, a paradigm in which external light input should be controlled. This represents a novel molecular imaging approach for non-invasive monitoring of local Ca2+ dynamics and cellular communication in tissue or whole animal studies.

  2. Genetically Encoded Biosensors Reveal PKA Hyperphosphorylation on the Myofilaments in Rabbit Heart Failure.

    Barbagallo, Federica; Xu, Bing; Reddy, Gopireddy R; West, Toni; Wang, Qingtong; Fu, Qin; Li, Minghui; Shi, Qian; Ginsburg, Kenneth S; Ferrier, William; Isidori, Andrea M; Naro, Fabio; Patel, Hemal H; Bossuyt, Julie; Bers, Donald; Xiang, Yang K

    2016-09-30

    In heart failure, myofilament proteins display abnormal phosphorylation, which contributes to contractile dysfunction. The mechanisms underlying the dysregulation of protein phosphorylation on myofilaments is not clear. This study aims to understand the mechanisms underlying altered phosphorylation of myofilament proteins in heart failure. We generate a novel genetically encoded protein kinase A (PKA) biosensor anchored onto the myofilaments in rabbit cardiac myocytes to examine PKA activity at the myofilaments in responses to adrenergic stimulation. We show that PKA activity is shifted from the sarcolemma to the myofilaments in hypertrophic failing rabbit myocytes. In particular, the increased PKA activity on the myofilaments is because of an enhanced β2 adrenergic receptor signal selectively directed to the myofilaments together with a reduced phosphodiesterase activity associated with the myofibrils. Mechanistically, the enhanced PKA activity on the myofilaments is associated with downregulation of caveolin-3 in the hypertrophic failing rabbit myocytes. Reintroduction of caveolin-3 in the failing myocytes is able to normalize the distribution of β2 adrenergic receptor signal by preventing PKA signal access to the myofilaments and to restore contractile response to adrenergic stimulation. In hypertrophic rabbit myocytes, selectively enhanced β2 adrenergic receptor signaling toward the myofilaments contributes to elevated PKA activity and PKA phosphorylation of myofilament proteins. Reintroduction of caveolin-3 is able to confine β2 adrenergic receptor signaling and restore myocyte contractility in response to β adrenergic stimulation. © 2016 American Heart Association, Inc.

  3. Visualization of Nicotine Adenine Dinucleotide Redox Homeostasis with Genetically Encoded Fluorescent Sensors.

    Zhao, Yuzheng; Zhang, Zhuo; Zou, Yejun; Yang, Yi

    2018-01-20

    Beyond their roles as redox currency in living organisms, pyridine dinucleotides (NAD + /NADH and NADP + /NADPH) are also precursors or cosubstrates of great significance in various physiologic and pathologic processes. Recent Advances: For many years, it was challenging to develop methodologies for monitoring pyridine dinucleotides in situ or in vivo. Recent advances in fluorescent protein-based sensors provide a rapid, sensitive, specific, and real-time readout of pyridine dinucleotide dynamics in single cells or in vivo, thereby opening a new era of pyridine dinucleotide bioimaging. In this article, we summarize the developments in genetically encoded fluorescent sensors for NAD + /NADH and NADP + /NADPH redox states, as well as their applications in life sciences and drug discovery. The strengths and weaknesses of individual sensors are also discussed. These sensors have the advantages of being specific and organelle targetable, enabling real-time monitoring and subcellular-level quantification of targeted molecules in living cells and in vivo. NAD + /NADH and NADP + /NADPH have distinct functions in metabolic and redox regulation, and thus, a comprehensive evaluation of metabolic and redox states must be multiplexed with a combination of various metabolite sensors in a single cell. Antioxid. Redox Signal. 28, 213-229.

  4. Fluorescent protein Dendra2 as a ratiometric genetically encoded pH-sensor.

    Pakhomov, Alexey A; Martynov, Vladimir I; Orsa, Alexander N; Bondarenko, Alena A; Chertkova, Rita V; Lukyanov, Konstantin A; Petrenko, Alexander G; Deyev, Igor E

    2017-12-02

    Fluorescent protein Dendra2 is a monomeric GFP-like protein that belongs to the group of Kaede-like photoconvertible fluorescent proteins with irreversible photoconversion from a green- to red-emitting state when exposed to violet-blue light. In an acidic environment, photoconverted Dendra2 turns green due to protonation of the phenolic group of the chromophore with pKa of about 7.5. Thus, photoconverted form of Dendra2 can be potentially used as a ratiometric pH-sensor in the physiological pH range. However, incomplete photoconversion makes ratiometric measurements irreproducible when using standard filter sets. Here, we describe the method to detect fluorescence of only photoconverted Dendra2 form, but not nonconverted green Dendra2. We show that the 350 nm excitation light induces solely the fluorescence of photoconverted protein. By measuring the red to green fluorescence ratio, we determined intracellular pH in live CHO and HEK 293 cells. Thus, Dendra2 can be used as a novel ratiometric genetically encoded pH sensor with emission maxima in the green-red spectral region, which is suitable for application in live cells. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Imaging intracellular pH in live cells with a genetically encoded red fluorescent protein sensor.

    Tantama, Mathew; Hung, Yin Pun; Yellen, Gary

    2011-07-06

    Intracellular pH affects protein structure and function, and proton gradients underlie the function of organelles such as lysosomes and mitochondria. We engineered a genetically encoded pH sensor by mutagenesis of the red fluorescent protein mKeima, providing a new tool to image intracellular pH in live cells. This sensor, named pHRed, is the first ratiometric, single-protein red fluorescent sensor of pH. Fluorescence emission of pHRed peaks at 610 nm while exhibiting dual excitation peaks at 440 and 585 nm that can be used for ratiometric imaging. The intensity ratio responds with an apparent pK(a) of 6.6 and a >10-fold dynamic range. Furthermore, pHRed has a pH-responsive fluorescence lifetime that changes by ~0.4 ns over physiological pH values and can be monitored with single-wavelength two-photon excitation. After characterizing the sensor, we tested pHRed's ability to monitor intracellular pH by imaging energy-dependent changes in cytosolic and mitochondrial pH.

  6. Flow Cytometry Enables Multiplexed Measurements of Genetically Encoded Intramolecular FRET Sensors Suitable for Screening.

    Doucette, Jaimee; Zhao, Ziyan; Geyer, Rory J; Barra, Melanie M; Balunas, Marcy J; Zweifach, Adam

    2016-07-01

    Genetically encoded sensors based on intramolecular FRET between CFP and YFP are used extensively in cell biology research. Flow cytometry has been shown to offer a means to measure CFP-YFP FRET; we suspected it would provide a unique way to conduct multiplexed measurements from cells expressing different FRET sensors, which is difficult to do with microscopy, and that this could be used for screening. We confirmed that flow cytometry accurately measures FRET signals using cells transiently transfected with an ERK activity reporter, comparing responses measured with imaging and cytometry. We created polyclonal long-term transfectant lines, each expressing a different intramolecular FRET sensor, and devised a way to bar-code four distinct populations of cells. We demonstrated the feasibility of multiplexed measurements and determined that robust multiplexed measurements can be conducted in plate format. To validate the suitability of the method for screening, we measured responses from a plate of bacterial extracts that in unrelated experiments we had determined contained the protein kinase C (PKC)-activating compound teleocidin A-1. The multiplexed assay correctly identifying the teleocidin A-1-containing well. We propose that multiplexed cytometric FRET measurements will be useful for analyzing cellular function and for screening compound collections. © 2016 Society for Laboratory Automation and Screening.

  7. Exploration of genetically encoded voltage indicators based on a chimeric voltage sensing domain

    Yukiko eMishina

    2014-09-01

    Full Text Available Deciphering how the brain generates cognitive function from patterns of electrical signals is one of the ultimate challenges in neuroscience. To this end, it would be highly desirable to monitor the activities of very large numbers of neurons while an animal engages in complex behaviours. Optical imaging of electrical activity using genetically encoded voltage indicators (GEVIs has the potential to meet this challenge. Currently prevalent GEVIs are based on the voltage-sensitive fluorescent protein (VSFP prototypical design or on the voltage dependent state transitions of microbial opsins.We recently introduced a new VSFP design in which the voltage-sensing domain (VSD is sandwiched between a FRET pair of fluorescent proteins (termed VSFP-Butterflies and also demonstrated a series of chimeric VSD in which portions of the VSD of Ciona intestinalis voltage-sensitive phosphatase (Ci-VSP are substituted by homologous portions of a voltage-gated potassium channel subunit. These chimeric VSD had faster sensing kinetics than that of the native Ci-VSD. Here, we describe a new set of VSFPs that combine chimeric VSD with the Butterfly structure. We show that these chimeric VSFP-Butterflies can report membrane voltage oscillations of up to 200 Hz in cultured cells and report sensory evoked cortical population responses in living mice. This class of GEVIs may be suitable for imaging of brain rhythms in behaving mammalians.

  8. Exploration of genetically encoded voltage indicators based on a chimeric voltage sensing domain.

    Mishina, Yukiko; Mutoh, Hiroki; Song, Chenchen; Knöpfel, Thomas

    2014-01-01

    Deciphering how the brain generates cognitive function from patterns of electrical signals is one of the ultimate challenges in neuroscience. To this end, it would be highly desirable to monitor the activities of very large numbers of neurons while an animal engages in complex behaviors. Optical imaging of electrical activity using genetically encoded voltage indicators (GEVIs) has the potential to meet this challenge. Currently prevalent GEVIs are based on the voltage-sensitive fluorescent protein (VSFP) prototypical design or on the voltage-dependent state transitions of microbial opsins. We recently introduced a new VSFP design in which the voltage-sensing domain (VSD) is sandwiched between a fluorescence resonance energy transfer pair of fluorescent proteins (termed VSFP-Butterflies) and also demonstrated a series of chimeric VSD in which portions of the VSD of Ciona intestinalis voltage-sensitive phosphatase are substituted by homologous portions of a voltage-gated potassium channel subunit. These chimeric VSD had faster sensing kinetics than that of the native Ci-VSD. Here, we describe a new set of VSFPs that combine chimeric VSD with the Butterfly structure. We show that these chimeric VSFP-Butterflies can report membrane voltage oscillations of up to 200 Hz in cultured cells and report sensory evoked cortical population responses in living mice. This class of GEVIs may be suitable for imaging of brain rhythms in behaving mammalians.

  9. Genetically encoded ratiometric fluorescent thermometer with wide range and rapid response.

    Masahiro Nakano

    Full Text Available Temperature is a fundamental physical parameter that plays an important role in biological reactions and events. Although thermometers developed previously have been used to investigate several important phenomena, such as heterogeneous temperature distribution in a single living cell and heat generation in mitochondria, the development of a thermometer with a sensitivity over a wide temperature range and rapid response is still desired to quantify temperature change in not only homeotherms but also poikilotherms from the cellular level to in vivo. To overcome the weaknesses of the conventional thermometers, such as a limitation of applicable species and a low temporal resolution, owing to the narrow temperature range of sensitivity and the thermometry method, respectively, we developed a genetically encoded ratiometric fluorescent temperature indicator, gTEMP, by using two fluorescent proteins with different temperature sensitivities. Our thermometric method enabled a fast tracking of the temperature change with a time resolution of 50 ms. We used this method to observe the spatiotemporal temperature change between the cytoplasm and nucleus in cells, and quantified thermogenesis from the mitochondria matrix in a single living cell after stimulation with carbonyl cyanide 4-(trifluoromethoxyphenylhydrazone, which was an uncoupler of oxidative phosphorylation. Moreover, exploiting the wide temperature range of sensitivity from 5°C to 50°C of gTEMP, we monitored the temperature in a living medaka embryo for 15 hours and showed the feasibility of in vivo thermometry in various living species.

  10. Genetically encoded lipid-polypeptide hybrid biomaterials that exhibit temperature-triggered hierarchical self-assembly

    Mozhdehi, Davoud; Luginbuhl, Kelli M.; Simon, Joseph R.; Dzuricky, Michael; Berger, Rüdiger; Varol, H. Samet; Huang, Fred C.; Buehne, Kristen L.; Mayne, Nicholas R.; Weitzhandler, Isaac; Bonn, Mischa; Parekh, Sapun H.; Chilkoti, Ashutosh

    2018-05-01

    Post-translational modification of proteins is a strategy widely used in biological systems. It expands the diversity of the proteome and allows for tailoring of both the function and localization of proteins within cells as well as the material properties of structural proteins and matrices. Despite their ubiquity in biology, with a few exceptions, the potential of post-translational modifications in biomaterials synthesis has remained largely untapped. As a proof of concept to demonstrate the feasibility of creating a genetically encoded biohybrid material through post-translational modification, we report here the generation of a family of three stimulus-responsive hybrid materials—fatty-acid-modified elastin-like polypeptides—using a one-pot recombinant expression and post-translational lipidation methodology. These hybrid biomaterials contain an amphiphilic domain, composed of a β-sheet-forming peptide that is post-translationally functionalized with a C14 alkyl chain, fused to a thermally responsive elastin-like polypeptide. They exhibit temperature-triggered hierarchical self-assembly across multiple length scales with varied structure and material properties that can be controlled at the sequence level.

  11. A Toolbox of Genetically Encoded FRET-Based Biosensors for Rapid l-Lysine Analysis

    Victoria Steffen

    2016-09-01

    Full Text Available Background: The fast development of microbial production strains for basic and fine chemicals is increasingly carried out in small scale cultivation systems to allow for higher throughput. Such parallelized systems create a need for new rapid online detection systems to quantify the respective target compound. In this regard, biosensors, especially genetically encoded Förster resonance energy transfer (FRET-based biosensors, offer tremendous opportunities. As a proof-of-concept, we have created a toolbox of FRET-based biosensors for the ratiometric determination of l-lysine in fermentation broth. Methods: The sensor toolbox was constructed based on a sensor that consists of an optimized central lysine-/arginine-/ornithine-binding protein (LAO-BP flanked by two fluorescent proteins (enhanced cyan fluorescent protein (ECFP, Citrine. Further sensor variants with altered affinity and sensitivity were obtained by circular permutation of the binding protein as well as the introduction of flexible and rigid linkers between the fluorescent proteins and the LAO-BP, respectively. Results: The sensor prototype was applied to monitor the extracellular l-lysine concentration of the l-lysine producing Corynebacterium glutamicum (C. glutamicum strain DM1933 in a BioLector® microscale cultivation device. The results matched well with data obtained by HPLC analysis and the Ninhydrin assay, demonstrating the high potential of FRET-based biosensors for high-throughput microbial bioprocess optimization.

  12. Fast two-photon imaging of subcellular voltage dynamics in neuronal tissue with genetically encoded indicators.

    Chamberland, Simon; Yang, Helen H; Pan, Michael M; Evans, Stephen W; Guan, Sihui; Chavarha, Mariya; Yang, Ying; Salesse, Charleen; Wu, Haodi; Wu, Joseph C; Clandinin, Thomas R; Toth, Katalin; Lin, Michael Z; St-Pierre, François

    2017-07-27

    Monitoring voltage dynamics in defined neurons deep in the brain is critical for unraveling the function of neuronal circuits but is challenging due to the limited performance of existing tools. In particular, while genetically encoded voltage indicators have shown promise for optical detection of voltage transients, many indicators exhibit low sensitivity when imaged under two-photon illumination. Previous studies thus fell short of visualizing voltage dynamics in individual neurons in single trials. Here, we report ASAP2s, a novel voltage indicator with improved sensitivity. By imaging ASAP2s using random-access multi-photon microscopy, we demonstrate robust single-trial detection of action potentials in organotypic slice cultures. We also show that ASAP2s enables two-photon imaging of graded potentials in organotypic slice cultures and in Drosophila . These results demonstrate that the combination of ASAP2s and fast two-photon imaging methods enables detection of neural electrical activity with subcellular spatial resolution and millisecond-timescale precision.

  13. Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization

    Arking, Dan E.; Pulit, Sara L.; Crotti, Lia; van der Harst, Pim; Munroe, Patricia B.; Koopmann, Tamara T.; Sotoodehnia, Nona; Rossin, Elizabeth J.; Morley, Michael; Wang, Xinchen; Johnson, Andrew D.; Lundby, Alicia; Gudbjartsson, Daníel F.; Noseworthy, Peter A.; Eijgelsheim, Mark; Bradford, Yuki; Tarasov, Kirill V.; Dörr, Marcus; Müller-Nurasyid, Martina; Lahtinen, Annukka M.; Nolte, Ilja M.; Smith, Albert Vernon; Bis, Joshua C.; Isaacs, Aaron; Newhouse, Stephen J.; Evans, Daniel S.; Post, Wendy S.; Waggott, Daryl; Lyytikäinen, Leo-Pekka; Hicks, Andrew A.; Eisele, Lewin; Ellinghaus, David; Hayward, Caroline; Navarro, Pau; Ulivi, Sheila; Tanaka, Toshiko; Tester, David J.; Chatel, Stéphanie; Gustafsson, Stefan; Kumari, Meena; Morris, Richard W.; Naluai, Åsa T.; Padmanabhan, Sandosh; Kluttig, Alexander; Strohmer, Bernhard; Panayiotou, Andrie G.; Torres, Maria; Knoflach, Michael; Hubacek, Jaroslav A.; Slowikowski, Kamil; Raychaudhuri, Soumya; Kumar, Runjun D.; Harris, Tamara B.; Launer, Lenore J.; Shuldiner, Alan R.; Alonso, Alvaro; Bader, Joel S.; Ehret, Georg; Huang, Hailiang; Kao, W.H. Linda; Strait, James B.; Macfarlane, Peter W.; Brown, Morris; Caulfield, Mark J.; Samani, Nilesh J.; Kronenberg, Florian; Willeit, Johann; Smith, J. Gustav; Greiser, Karin H.; zu Schwabedissen, Henriette Meyer; Werdan, Karl; Carella, Massimo; Zelante, Leopoldo; Heckbert, Susan R.; Psaty, Bruce M.; Rotter, Jerome I.; Kolcic, Ivana; Polašek, Ozren; Wright, Alan F.; Griffin, Maura; Daly, Mark J.; Arnar, David O.; Hólm, Hilma; Thorsteinsdottir, Unnur; Denny, Joshua C.; Roden, Dan M.; Zuvich, Rebecca L.; Emilsson, Valur; Plump, Andrew S.; Larson, Martin G.; O'Donnell, Christopher J.; Yin, Xiaoyan; Bobbo, Marco; D'Adamo, Adamo P.; Iorio, Annamaria; Sinagra, Gianfranco; Carracedo, Angel; Cummings, Steven R.; Nalls, Michael A.; Jula, Antti; Kontula, Kimmo K.; Marjamaa, Annukka; Oikarinen, Lasse; Perola, Markus; Porthan, Kimmo; Erbel, Raimund; Hoffmann, Per; Jöckel, Karl-Heinz; Kälsch, Hagen; Nöthen, Markus M.; consortium, HRGEN; den Hoed, Marcel; Loos, Ruth J.F.; Thelle, Dag S.; Gieger, Christian; Meitinger, Thomas; Perz, Siegfried; Peters, Annette; Prucha, Hanna; Sinner, Moritz F.; Waldenberger, Melanie; de Boer, Rudolf A.; Franke, Lude; van der Vleuten, Pieter A.; Beckmann, Britt Maria; Martens, Eimo; Bardai, Abdennasser; Hofman, Nynke; Wilde, Arthur A.M.; Behr, Elijah R.; Dalageorgou, Chrysoula; Giudicessi, John R.; Medeiros-Domingo, Argelia; Barc, Julien; Kyndt, Florence; Probst, Vincent; Ghidoni, Alice; Insolia, Roberto; Hamilton, Robert M.; Scherer, Stephen W.; Brandimarto, Jeffrey; Margulies, Kenneth; Moravec, Christine E.; Fabiola Del, Greco M.; Fuchsberger, Christian; O'Connell, Jeffrey R.; Lee, Wai K.; Watt, Graham C.M.; Campbell, Harry; Wild, Sarah H.; El Mokhtari, Nour E.; Frey, Norbert; Asselbergs, Folkert W.; Leach, Irene Mateo; Navis, Gerjan; van den Berg, Maarten P.; van Veldhuisen, Dirk J.; Kellis, Manolis; Krijthe, Bouwe P.; Franco, Oscar H.; Hofman, Albert; Kors, Jan A.; Uitterlinden, André G.; Witteman, Jacqueline C.M.; Kedenko, Lyudmyla; Lamina, Claudia; Oostra, Ben A.; Abecasis, Gonçalo R.; Lakatta, Edward G.; Mulas, Antonella; Orrú, Marco; Schlessinger, David; Uda, Manuela; Markus, Marcello R.P.; Völker, Uwe; Snieder, Harold; Spector, Timothy D.; Ärnlöv, Johan; Lind, Lars; Sundström, Johan; Syvänen, Ann-Christine; Kivimaki, Mika; Kähönen, Mika; Mononen, Nina; Raitakari, Olli T.; Viikari, Jorma S.; Adamkova, Vera; Kiechl, Stefan; Brion, Maria; Nicolaides, Andrew N.; Paulweber, Bernhard; Haerting, Johannes; Dominiczak, Anna F.; Nyberg, Fredrik; Whincup, Peter H.; Hingorani, Aroon; Schott, Jean-Jacques; Bezzina, Connie R.; Ingelsson, Erik; Ferrucci, Luigi; Gasparini, Paolo; Wilson, James F.; Rudan, Igor; Franke, Andre; Mühleisen, Thomas W.; Pramstaller, Peter P.; Lehtimäki, Terho J.; Paterson, Andrew D.; Parsa, Afshin; Liu, Yongmei; van Duijn, Cornelia; Siscovick, David S.; Gudnason, Vilmundur; Jamshidi, Yalda; Salomaa, Veikko; Felix, Stephan B.; Sanna, Serena; Ritchie, Marylyn D.; Stricker, Bruno H.; Stefansson, Kari; Boyer, Laurie A.; Cappola, Thomas P.; Olsen, Jesper V.; Lage, Kasper; Schwartz, Peter J.; Kääb, Stefan; Chakravarti, Aravinda; Ackerman, Michael J.; Pfeufer, Arne; de Bakker, Paul I.W.; Newton-Cheh, Christopher

    2014-01-01

    The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal Mendelian Long QT Syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals we identified 35 common variant QT interval loci, that collectively explain ∼8-10% of QT variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 novel QT loci in 298 unrelated LQTS probands identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode for proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies novel candidate genes for ventricular arrhythmias, LQTS,and SCD. PMID:24952745

  14. Nutritional rickets: vitamin D, calcium, and the genetic make-up.

    El Kholy, Mohamed; Elsedfy, Heba; Fernández-Cancio, Monica; Hamza, Rasha Tarif; Amr, Nermine Hussein; Ahmed, Alaa Youssef; Toaima, Nadin Nabil; Audí, Laura

    2017-02-01

    The prevalence of vitamin D (vitD) deficiency presenting as rickets is increasing worldwide. Insufficient sun exposure, vitD administration, and/or calcium intake are the main causes. However, vitD system-related genes may also have a role. Prospective study: 109 rachitic children completed a 6-mo study period or until rachitic manifestations disappeared. Thirty children were selected as controls. Clinical and biochemical data were evaluated at baseline in patients and controls and biochemistry re-evaluated at radiological healing. Therapy was stratified in three different protocols. Fifty-four single-nucleotide polymorphisms (SNPs) of five vitD system genes (VDR, CP2R1, CYP27B1, CYP24A1, and GC) were genotyped and their association with clinical and biochemcial data was analyzed. Therapy response was similar in terms of radiological healing although it was not so in terms of biochemical normalization. Only VDR gene (promoter, start-codon, and intronic genotypes) was rickets-associated in terms of serum 25-OH-D, calcium, radiological severity and time needed to heal. Eight patients with sufficient calcium intake and 25-OH-D levels carried a VDR genotype lacking minor allele homozygous genotypes at SNPs spread along the gene. Although patients presented epidemiologic factors strongly contributing to rickets, genetic modulation affecting predisposition, severity, and clinical course is exerted, at least in part, by VDR gene polymorphic variation.

  15. Mechanistic studies of the genetically encoded fluorescent protein voltage probe ArcLight.

    Zhou Han

    Full Text Available ArcLight, a genetically encoded fluorescent protein voltage probe with a large ΔF/ΔV, is a fusion between the voltage sensing domain of the Ciona instestinalis voltage sensitive phosphatase and super ecliptic pHluorin carrying a single mutation (A227D in the fluorescent protein. Without this mutation the probe produces only a very small change in fluorescence in response to voltage deflections (∼ 1%. The large signal afforded by this mutation allows optical detection of action potentials and sub-threshold electrical events in single-trials in vitro and in vivo. However, it is unclear how this single mutation produces a probe with such a large modulation of its fluorescence output with changes in membrane potential. In this study, we identified which residues in super ecliptic pHluorin (vs eGFP are critical for the ArcLight response, as a similarly constructed probe based on eGFP also exhibits large response amplitude if it carries these critical residues. We found that D147 is responsible for determining the pH sensitivity of the fluorescent protein used in these probes but by itself does not result in a voltage probe with a large signal. We also provide evidence that the voltage dependent signal of ArcLight is not simply sensing environmental pH changes. A two-photon polarization microscopy study showed that ArcLight's response to changes in membrane potential includes a reorientation of the super ecliptic pHluorin. We also explored different changes including modification of linker length, deletion of non-essential amino acids in the super ecliptic pHluorin, adding a farnesylation site, using tandem fluorescent proteins and other pH sensitive fluorescent proteins.

  16. Genetically-encoded tools for cAMP probing and modulation in living systems.

    Valeriy M Paramonov

    2015-09-01

    Full Text Available Intracellular 3'-5'-cyclic adenosine monophosphate (cAMP is one of the principal second messengers downstream of a manifold of signal transduction pathways, including the ones triggered by G protein-coupled receptors. Not surprisingly, biochemical assays for cAMP have been instrumental for basic research and drug discovery for decades, providing insights into cellular physiology and guiding pharmaceutical industry. However, despite impressive track record, the majority of conventional biochemical tools for cAMP probing share the same fundamental shortcoming - all the measurements require sample disruption for cAMP liberation. This common bottleneck, together with inherently low spatial resolution of measurements (as cAMP is typically analyzed in lysates of thousands of cells, underpin the ensuing limitations of the conventional cAMP assays: 1 genuine kinetic measurements of cAMP levels over time in a single given sample are unfeasible; 2 inability to obtain precise information on cAMP spatial distribution and transfer at subcellular levels, let alone the attempts to pinpoint dynamic interactions of cAMP and its effectors. At the same time, tremendous progress in synthetic biology over the recent years culminated in drastic refinement of our toolbox, allowing us not only to bypass the limitations of conventional assays, but to put intracellular cAMP life-span under tight control – something, that seemed scarcely attainable before. In this review article we discuss the main classes of modern genetically-encoded tools tailored for cAMP probing and modulation in living systems. We examine the capabilities and weaknesses of these different tools in the context of their operational characteristics and applicability to various experimental set-ups involving living cells, providing the guidance for rational selection of the best tools for particular needs.

  17. Modulating the Voltage-sensitivity of a Genetically Encoded Voltage Indicator.

    Jung, Arong; Rajakumar, Dhanarajan; Yoon, Bong-June; Baker, Bradley J

    2017-10-01

    Saturation mutagenesis was performed on a single position in the voltage-sensing domain (VSD) of a genetically encoded voltage indicator (GEVI). The VSD consists of four transmembrane helixes designated S1-S4. The V220 position located near the plasma membrane/extracellular interface had previously been shown to affect the voltage range of the optical signal. Introduction of polar amino acids at this position reduced the voltage-dependent optical signal of the GEVI. Negatively charged amino acids slightly reduced the optical signal by 33 percent while positively charge amino acids at this position reduced the optical signal by 80%. Surprisingly, the range of V220D was similar to that of V220K with shifted optical responses towards negative potentials. In contrast, the V220E mutant mirrored the responses of the V220R mutation suggesting that the length of the side chain plays in role in determining the voltage range of the GEVI. Charged mutations at the 219 position all behaved similarly slightly shifting the optical response to more negative potentials. Charged mutations to the 221 position behaved erratically suggesting interactions with the plasma membrane and/or other amino acids in the VSD. Introduction of bulky amino acids at the V220 position increased the range of the optical response to include hyperpolarizing signals. Combining The V220W mutant with the R217Q mutation resulted in a probe that reduced the depolarizing signal and enhanced the hyperpolarizing signal which may lead to GEVIs that only report neuronal inhibition.

  18. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Raimondo, Joseph V.; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E.; Srinivas, Shankar; Akerman, Colin J.

    2013-01-01

    Within the nervous system, intracellular Cl− and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl− and pH are often co-regulated, and network activity results in the movement of both Cl− and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl− and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN—a new genetically-encoded ratiometric Cl− and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl− and H+ concentrations under a variety of conditions. In addition, we establish the sensor's utility by characterizing activity-dependent ion dynamics in hippocampal neurons. PMID:24312004

  19. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system.

    Raimondo, Joseph V; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E; Srinivas, Shankar; Akerman, Colin J

    2013-01-01

    Within the nervous system, intracellular Cl(-) and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl(-) and pH are often co-regulated, and network activity results in the movement of both Cl(-) and H(+). Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl(-) and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN-a new genetically-encoded ratiometric Cl(-) and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl(-) and H(+) concentrations under a variety of conditions. In addition, we establish the sensor's utility by characterizing activity-dependent ion dynamics in hippocampal neurons.

  20. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Joseph Valentino Raimondo

    2013-11-01

    Full Text Available Within the nervous system, intracellular Cl- and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission and network excitability. Cl- and pH are often co-regulated, and network activity results in the movement of both Cl- and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl- and pH sensors have been described previously, these either lack ion specificity or are unsuitable for neuronal use. Here we present ClopHensorN - a new genetically-encoded ratiometric Cl- and pH sensor that is optimized for the nervous system. We demonstrate the ability of ClopHensorN to dissociate and simultaneously quantify Cl- and H+ concentrations under a variety of conditions. In addition, we establish the sensor’s utility by characterizing activity-dependent ion dynamics in hippocampal neurons.

  1. Molecular cloning and expression of cDNA encoding a lumenal calcium binding glycoprotein from sarcoplasmic reticulum

    Leberer, E.; Charuk, J.H.M.; MacLennan, D.H.; Green, N.M.

    1989-01-01

    Antibody screening was used to isolate a cDNA encoding the 160-kDa glycoprotein of rabbit skeletal muscle sarcoplasmic reticulum. The cDNA is identical to that encoding the 53-kDa glycoprotein except that it contains an in-frame insertion of 1,308 nucleotides near its 5' end, apparently resulting from alternative splicing. The protein encoded by the cDNA would contain a 19-residue NH 2 -terminal signal sequence and a 453-residue COOH-terminal sequence identical to the 53-kDa glycoprotein. It would also contain a 436-amino acid insert between these sequences. This insert would be highly acidic, suggesting that it might bind Ca 2+ . The purified 160-kDa glycoprotein and the glycoprotein expressed in COS-1 cells transfected with cDNA encoding the 160-kDa glycoprotein were shown to bind 45 C 2+ in a gel overlay assay. The protein was shown to be located in the lumen of the sarcoplasmic reticulum and to be associated through Ca 2+ with the membrane. The authors propose that this lumenal Ca 2+ binding glycoprotein of the sarcoplasmic reticulum be designated sarcalumenin

  2. A genetically-encoded chloride and pH sensor for dissociating ion dynamics in the nervous system

    Raimondo, Joseph V.; Joyce, Bradley; Kay, Louise; Schlagheck, Theresa; Newey, Sarah E.; Srinivas, Shankar; Akerman, Colin J.

    2013-01-01

    Within the nervous system, intracellular Cl− and pH regulate fundamental processes including cell proliferation, metabolism, synaptic transmission, and network excitability. Cl− and pH are often co-regulated, and network activity results in the movement of both Cl− and H+. Tools to accurately measure these ions are crucial for understanding their role under physiological and pathological conditions. Although genetically-encoded Cl− and pH sensors have been described previously, these either l...

  3. Engineering of a genetically encodable fluorescent voltage sensor exploiting fast Ci-VSP voltage-sensing movements.

    Lundby, Alicia; Mutoh, Hiroki; Dimitrov, Dimitar; Akemann, Walther; Knöpfel, Thomas

    2008-06-25

    Ci-VSP contains a voltage-sensing domain (VSD) homologous to that of voltage-gated potassium channels. Using charge displacement ('gating' current) measurements we show that voltage-sensing movements of this VSD can occur within 1 ms in mammalian membranes. Our analysis lead to development of a genetically encodable fluorescent protein voltage sensor (VSFP) in which the fast, voltage-dependent conformational changes of the Ci-VSP voltage sensor are transduced to similarly fast fluorescence read-outs.

  4. Calibration and functional analysis of three genetically encoded Cl−/pH sensors

    Marat eMukhtarov

    2013-04-01

    Full Text Available Monitoring of the intracellular concentrations of Cl− and H+ requires sensitive probes that allow reliable quantitative measurements without perturbation of cell functioning. For these purposes the most promising are genetically encoded fluorescent biosensors, which have become powerful tools for non-invasive intracellular monitoring of ions, molecules and enzymatic activity. A ratiometric CFP/YFP-based construct with a relatively good sensitivity to Cl− has been developed (Markova et al., 2008; Waseem et al., 2010. Recently, a combined Cl−/pH sensor (ClopHensor opened the way for simultaneous ratiometric measurement of these two ions (Arosio et al., 2010. ClopHensor was obtained by fusion of a red-fluorescent protein (DsRed-monomer to the E2GFP variant that contains a specific Cl−-binding site. This construct possesses pKa = 6.8 for H+ and Kd in the 40-50 mM range for Cl− at physiological pH (~7.3 As in the majority of cell types the intracellular Cl− concentration ([Cl−]i is about 10 mM, the development of sensors with higher sensitivity is highly desirable. Here we report the intracellular calibration and functional characterization of ClopHensor and its two derivatives: the membrane targeting PalmPalm-ClopHensor and the H148G/V224L mutant with improved Cl− affinity, reduced pH dependence and pKa shifted to more alkaline values. For functional analysis, constructs were expressed in CHO cells and [Cl−]i was changed by using pipettes with different Cl− concentrations during whole-cell recordings. Kd values for Cl− measured at 33°C and pH ~ 7.3 were, respectively, 39 mM, 47 mM and 21 mM for ClopHensor, PalmPalm-ClopHensor and the H148G/V224L mutant. PalmPalm-ClopHensor resolved responses to activation of Cl−-selective glycine receptor channels better than did ClopHensor. Our observations indicate that these different ClopHensor constructs are promising tools for non-invasive measurement of [Cl−]i in various living

  5. The Genetic and Molecular Bases for Hypertrophic Cardiomyopathy: The Role for Calcium Sensitization.

    Ren, Xianfeng; Hensley, Nadia; Brady, Mary Beth; Gao, Wei Dong

    2018-02-01

    Hypertrophic cardiomyopathy (HCM) affects millions of people around the world as one of the most common genetic heart disorders and leads to cardiac ischemia, heart failure, dysfunction of other organ systems, and increased risk for sudden unexpected cardiac deaths. HCM can be caused by single-point mutations, insertion or deletion mutations, or truncation of cardiac myofilament proteins. The molecular mechanism that leads to disease progression and presentation is still poorly understood, despite decades of investigations. However, recent research has made dramatic advances in the understanding of HCM disease development. Studies have shown that increased calcium sensitivity is a universal feature in HCM. At the molecular level, increased crossbridge force (or power) generation resulting in hypercontractility is the prominent feature. Thus, calcium sensitization/hypercontractility is emerging as the primary stimulus for HCM disease development and phenotypic expression. Cross-bridge inhibition has been shown to halt HCM presentation, and myofilament desensitization appears to reduce lethal arrhythmias in animal models of HCM. These advances in basic research will continue to deepen the knowledge of HCM pathogenesis and are beginning to revolutionize the management of HCM. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. A strategy for genetic modification of the spike-encoding segment of human reovirus T3D for reovirus targeting.

    van den Wollenberg, D J M; van den Hengel, S K; Dautzenberg, I J C; Cramer, S J; Kranenburg, O; Hoeben, R C

    2008-12-01

    Human Orthoreovirus Type 3 Dearing is not pathogenic to humans and has been evaluated clinically as an oncolytic agent. Its transduction efficiency and the tumor cell selectivity may be enhanced by incorporating ligands for alternative receptors. However, the genetic modification of reoviruses has been difficult, and genetic targeting of reoviruses has not been reported so far. Here we describe a technique for generating genetically targeted reoviruses. The propagation of wild-type reoviruses on cells expressing a modified sigma 1-encoding segment embedded in a conventional RNA polymerase II transcript leads to substitution of the wild-type genome segment by the modified version. This technique was used for generating reoviruses that are genetically targeted to an artificial receptor expressed on U118MG cells. These cells lack the junction adhesion molecule-1 and therefore resist infection by wild-type reoviruses. The targeted reoviruses were engineered to carry the ligand for this receptor at the C terminus of the sigma 1 spike protein. This demonstrates that the C terminus of the sigma 1 protein is a suitable locale for the insertion of oligopeptide ligands and that targeting of reoviruses is feasible. The genetically targeted viruses can be propagated using the modified U118MG cells as helper cells. This technique may be applicable for the improvement of human reoviruses as oncolytic agents.

  7. Imaging Intracellular pH in Live Cells with a Genetically-Encoded Red Fluorescent Protein Sensor

    Tantama, Mathew; Hung, Yin Pun; Yellen, Gary

    2011-01-01

    Intracellular pH affects protein structure and function, and proton gradients underlie the function of organelles such as lysosomes and mitochondria. We engineered a genetically-encoded pH sensor by mutagenesis of the red fluorescent protein mKeima, providing a new tool to image intracellular pH in live cells. This sensor, named pHRed, is the first ratiometric, single-protein red fluorescent sensor of pH. Fluorescence emission of pHRed peaks at 610 nm while exhibiting dual excitation peaks at...

  8. Engineering of a genetically encodable fluorescent voltage sensor exploiting fast Ci-VSP voltage-sensing movements.

    Alicia Lundby

    2008-06-01

    Full Text Available Ci-VSP contains a voltage-sensing domain (VSD homologous to that of voltage-gated potassium channels. Using charge displacement ('gating' current measurements we show that voltage-sensing movements of this VSD can occur within 1 ms in mammalian membranes. Our analysis lead to development of a genetically encodable fluorescent protein voltage sensor (VSFP in which the fast, voltage-dependent conformational changes of the Ci-VSP voltage sensor are transduced to similarly fast fluorescence read-outs.

  9. Genetic and phylogenetic characterization of the type II cyclobutane pyrimidine dimer photolyases encoded by Leporipoxviruses

    Bennett, C. James; Webb, Melissa; Willer, David O.; Evans, David H.

    2003-01-01

    Shope fibroma virus and myxoma virus encode proteins predicted to be Type II photolyases. These are enzymes that catalyze light-dependent repair of cyclobutane pyrimidine dimers (CPDs). When the Shope fibroma virus S127L gene was expressed in an Escherichia coli strain lacking functional CPD repair pathways, the expressed gene protected the bacteria from 70-75% of the ultraviolet (UV) light-induced cytotoxic DNA damage. This proportion suggests that Leporipoxvirus photolyases can only repair CPDs, which typically comprise ∼70% of the damage caused by short wavelength UV light. To test whether these enzymes can protect virus genomes from UV, we exposed virus suspensions to UV-C light followed by graded exposure to filtered visible light. Viruses encoding a deletion of the putative photolyase gene were unable to photoreactivate UV damage while this treatment again eliminated 70-90% of the lethal photoproducts in wild-type viruses. Western blotting detected photolyase protein in extracts prepared from purified virions and it can be deduced that the poxvirion interior must be fluid enough to permit diffusion of this ∼50-kDa DNA-binding protein to the sites where it catalyzes photoreactivation. Photolyase promoters are difficult to categorize using bioinformatics methods, as they do not obviously resemble any of the known poxvirus promoter motifs. By fusing the SFV promoter to DNA encoding a luciferase open reading frame, the photolyase promoter was found to exhibit very weak late promoter activity. These data show that the genomes of Leporipoxviruses, similar to that of fowlpox virus, encode catalytically active photolyases. Phylogenetic studies also confirmed the monophyletic origin of poxviruses and suggest an ancient origin for these genes and perhaps poxviruses

  10. A genetically encoded ratiometric sensor to measure extracellular pH in microdomains bounded by basolateral membranes of epithelial cells.

    Urra, Javier; Sandoval, Moisés; Cornejo, Isabel; Barros, L Felipe; Sepúlveda, Francisco V; Cid, L Pablo

    2008-10-01

    Extracellular pH, especially in relatively inaccessible microdomains between cells, affects transport membrane protein activity and might have an intercellular signaling role. We have developed a genetically encoded extracellular pH sensor capable of detecting pH changes in basolateral spaces of epithelial cells. It consists of a chimerical membrane protein displaying concatenated enhanced variants of cyan fluorescence protein (ECFP) and yellow fluorescence protein (EYFP) at the external aspect of the cell surface. The construct, termed pHCECSensor01, was targeted to basolateral membranes of Madin-Darby canine kidney (MDCK) cells by means of a sequence derived from the aquaporin AQP4. The fusion of pH-sensitive EYFP with pH-insensitive ECFP allows ratiometric pH measurements. The titration curve of pHCECSensor01 in vivo had a pK (a) value of 6.5 +/- 0.04. Only minor effects of extracellular chloride on pHCECSensor01 were observed around the physiological concentrations of this anion. In MDCK cells, the sensor was able to detect changes in pH secondary to H(+) efflux into the basolateral spaces elicited by an ammonium prepulse or lactate load. This genetically encoded sensor has the potential to serve as a noninvasive tool for monitoring changes in extracellular pH microdomains in epithelial and other tissues in vivo.

  11. Imaging of Intracellular pH in Tumor Spheroids Using Genetically Encoded Sensor SypHer2.

    Zagaynova, Elena V; Druzhkova, Irina N; Mishina, Natalia M; Ignatova, Nadezhda I; Dudenkova, Varvara V; Shirmanova, Marina V

    2017-01-01

    Intracellular pH (pHi) is one of the most important parameters that regulate the physiological state of cells and tissues. pHi homeostasis is crucial for normal cell functioning. Cancer cells are characterized by having a higher (neutral to slightly alkaline) pHi and lower (acidic) extracellular pH (pHe) compared to normal cells. This is referred to as a "reversed" pH gradient, and is essential in supporting their accelerated growth rate, invasion and migration, and in suppressing anti-tumor immunity, the promotion of metabolic coupling with fibroblasts and in preventing apoptosis. Moreover, abnormal pH, both pHi and pHe, contribute to drug resistance in cancers. Therefore, the development of methods for measuring pH in living tumor cells is likely to lead to better understanding of tumor biology and to open new ways for cancer treatment. Genetically encoded, fluorescent, pH-sensitive probes represent promising instruments enabling the subcellular measurement of pHi with unrivaled specificity and high accuracy. Here, we describe a protocol for pHi imaging at a microscopic level in HeLa tumor spheroids, using the genetically encoded ratiometric (dual-excitation) pHi indicator, SypHer2.

  12. Observational and Genetic Associations of Resting Heart Rate With Aortic Valve Calcium.

    Whelton, Seamus P; Mauer, Andreas C; Pencina, Karol M; Massaro, Joseph M; D'Agostino, Ralph B; Fox, Caroline S; Hoffmann, Udo; Michos, Erin D; Peloso, Gina M; Dufresne, Line; Engert, James C; Kathiresan, Sekar; Budoff, Matthew; Post, Wendy S; Thanassoulis, George; O'Donnell, Christopher J

    2018-05-15

    It is unknown if lifelong exposure to increased hemodynamic stress from an elevated resting heart rate (HR) may contribute to aortic valve calcium (AVC). We performed multivariate regression analyses using data from 1,266 Framingham Heart Study (FHS) Offspring cohort participants and 6,764 Multi-Ethnic Study of Atherosclerosis (MESA) participants. We constructed a genetic risk score (GRS) for HR using summary-level data in the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) AVC Consortium to investigate if there was evidence in favor of a causal relation. AVC was present in 39% of FHS Offspring cohort participants and in 13% of MESA cohort participants. In multivariate adjusted models, participants in the highest resting HR quartiles had significantly greater prevalence of AVC, with a prevalence ratio of 1.19 (95% confidence interval [CI] 0.99 to 1.44) for the FHS Offspring cohort and 1.32 (95% CI 1.12 to 1.63) for the MESA cohort, compared with those in the lowest quartile. There was a similar increase in the prevalence of AVC per standard deviation increase in resting HR in both FHS Offspring (prevalence ratio 1.08, 95% CI 1.01 to 1.15) and MESA (1.10, 95% CI 1.03 to 1.17). In contrast with these observational findings, a HR associated GRS was not significantly associated with AVC. Although our observational analysis indicates that a higher resting HR is associated with AVC, our genetic results do not support a causal relation. Unmeasured environmental and/or lifestyle factors associated with both increased resting HR and AVC that are not fully explained by covariates in our observational models may account for the association between resting HR and AVC. Copyright © 2018. Published by Elsevier Inc.

  13. Heterogeneous genetic diversity pattern in Plasmodium vivax genes encoding merozoite surface proteins (MSP) -7E, -7F and -7L.

    Garzón-Ospina, Diego; Forero-Rodríguez, Johanna; Patarroyo, Manuel A

    2014-12-13

    The msp-7 gene has become differentially expanded in the Plasmodium genus; Plasmodium vivax has the highest copy number of this gene, several of which encode antigenic proteins in merozoites. DNA sequences from thirty-six Colombian clinical isolates from P. vivax (pv) msp-7E, -7F and -7L genes were analysed for characterizing and studying the genetic diversity of these pvmsp-7 members which are expressed during the intra-erythrocyte stage; natural selection signals producing the variation pattern so observed were evaluated. The pvmsp-7E gene was highly polymorphic compared to pvmsp-7F and pvmsp-7L which were seen to have limited genetic diversity; pvmsp-7E polymorphism was seen to have been maintained by different types of positive selection. Even though these copies seemed to be species-specific duplications, a search in the Plasmodium cynomolgi genome (P. vivax sister taxon) showed that both species shared the whole msp-7 repertoire. This led to exploring the long-term effect of natural selection by comparing the orthologous sequences which led to finding signatures for lineage-specific positive selection. The results confirmed that the P. vivax msp-7 family has a heterogeneous genetic diversity pattern; some members are highly conserved whilst others are highly diverse. The results suggested that the 3'-end of these genes encode MSP-7 proteins' functional region whilst the central region of pvmsp-7E has evolved rapidly. The lineage-specific positive selection signals found suggested that mutations occurring in msp-7s genes during host switch may have succeeded in adapting the ancestral P. vivax parasite population to humans.

  14. Illumination of the Spatial Order of Intracellular pH by Genetically Encoded pH-Sensitive Sensors

    Mojca Benčina

    2013-12-01

    Full Text Available Fluorescent proteins have been extensively used for engineering genetically encoded sensors that can monitor levels of ions, enzyme activities, redox potential, and metabolites. Certain fluorescent proteins possess specific pH-dependent spectroscopic features, and thus can be used as indicators of intracellular pH. Moreover, concatenated pH-sensitive proteins with target proteins pin the pH sensors to a definite location within the cell, compartment, or tissue. This study provides an overview of the continually expanding family of pH-sensitive fluorescent proteins that have become essential tools for studies of pH homeostasis and cell physiology. We describe and discuss the design of intensity-based and ratiometric pH sensors, their spectral properties and pH-dependency, as well as their performance. Finally, we illustrate some examples of the applications of pH sensors targeted at different subcellular compartments.

  15. Rapid Cellular Phenotyping of Human Pluripotent Stem Cell-Derived Cardiomyocytes using a Genetically Encoded Fluorescent Voltage Sensor

    Jordan S. Leyton-Mange

    2014-02-01

    Full Text Available In addition to their promise in regenerative medicine, pluripotent stem cells have proved to be faithful models of many human diseases. In particular, patient-specific stem cell-derived cardiomyocytes recapitulate key features of several life-threatening cardiac arrhythmia syndromes. For both modeling and regenerative approaches, phenotyping of stem cell-derived tissues is critical. Cellular phenotyping has largely relied upon expression of lineage markers rather than physiologic attributes. This is especially true for cardiomyocytes, in part because electrophysiological recordings are labor intensive. Likewise, most optical voltage indicators suffer from phototoxicity, which damages cells and degrades signal quality. Here we present the use of a genetically encoded fluorescent voltage indicator, ArcLight, which we demonstrate can faithfully report transmembrane potentials in human stem cell-derived cardiomyocytes. We demonstrate the application of this fluorescent sensor in high-throughput, serial phenotyping of differentiating cardiomyocyte populations and in screening for drug-induced cardiotoxicity.

  16. Voltage-gated calcium flux mediates Escherichia coli mechanosensation.

    Bruni, Giancarlo N; Weekley, R Andrew; Dodd, Benjamin J T; Kralj, Joel M

    2017-08-29

    Electrically excitable cells harness voltage-coupled calcium influx to transmit intracellular signals, typically studied in neurons and cardiomyocytes. Despite intense study in higher organisms, investigations of voltage and calcium signaling in bacteria have lagged due to their small size and a lack of sensitive tools. Only recently were bacteria shown to modulate their membrane potential on the timescale of seconds, and little is known about the downstream effects from this modulation. In this paper, we report on the effects of electrophysiology in individual bacteria. A genetically encoded calcium sensor expressed in Escherichia coli revealed calcium transients in single cells. A fusion sensor that simultaneously reports voltage and calcium indicated that calcium influx is induced by voltage depolarizations, similar to metazoan action potentials. Cytoplasmic calcium levels and transients increased upon mechanical stimulation with a hydrogel, and single cells altered protein concentrations dependent on the mechanical environment. Blocking voltage and calcium flux altered mechanically induced changes in protein concentration, while inducing calcium flux reproduced these changes. Thus, voltage and calcium relay a bacterial sense of touch and alter cellular lifestyle. Although the calcium effectors remain unknown, these data open a host of new questions about E. coli , including the identity of the underlying molecular players, as well as other signals conveyed by voltage and calcium. These data also provide evidence that dynamic voltage and calcium exists as a signaling modality in the oldest domain of life, and therefore studying electrophysiology beyond canonical electrically excitable cells could yield exciting new findings.

  17. Modulating and Measuring Intracellular H2O2 Using Genetically Encoded Tools to Study Its Toxicity to Human Cells.

    Huang, Beijing K; Stein, Kassi T; Sikes, Hadley D

    2016-12-16

    Reactive oxygen species (ROS) such as H 2 O 2 play paradoxical roles in mammalian physiology. It is hypothesized that low, baseline levels of H 2 O 2 are necessary for growth and differentiation, while increased intracellular H 2 O 2 concentrations are associated with pathological phenotypes and genetic instability, eventually reaching a toxic threshold that causes cell death. However, the quantities of intracellular H 2 O 2 that lead to these different responses remain an unanswered question in the field. To address this question, we used genetically encoded constructs that both generate and quantify H 2 O 2 in a dose-response study of H 2 O 2 -mediated toxicity. We found that, rather than a simple concentration-response relationship, a combination of intracellular concentration and the cumulative metric of H 2 O 2 concentration multiplied by time (i.e., the area under the curve) determined the occurrence and level of cell death. Establishing the quantitative relationship between H 2 O 2 and cell toxicity promotes a deeper understanding of the intracellular effects of H 2 O 2 specifically as an individual reactive oxygen species, and it contributes to an understanding of its role in various redox-related diseases.

  18. Electron microscopy using the genetically encoded APEX2 tag in cultured mammalian cells

    Martell, Jeffrey D; Deerinck, Thomas J; Lam, Stephanie S; Ellisman, Mark H; Ting, Alice Y

    2018-01-01

    Electron microscopy (EM) is the premiere technique for high-resolution imaging of cellular ultrastructure. Unambiguous identification of specific proteins or cellular compartments in electron micrographs, however, remains challenging because of difficulties in delivering electron-dense contrast agents to specific subcellular targets within intact cells. We recently reported enhanced ascorbate peroxidase 2 (APEX2) as a broadly applicable genetic tag that generates EM contrast on a specific protein or subcellular compartment of interest. This protocol provides guidelines for designing and validating APEX2 fusion constructs, along with detailed instructions for cell culture, transfection, fixation, heavy-metal staining, embedding in resin, and EM imaging. Although this protocol focuses on EM in cultured mammalian cells, APEX2 is applicable to many cell types and contexts, including intact tissues and organisms, and is useful for numerous applications beyond EM, including live-cell proteomic mapping. This protocol, which describes procedures for sample preparation from cell monolayers and cell pellets, can be completed in 10 d, including time for APEX2 fusion construct validation, cell growth, and solidification of embedding resins. Notably, the only additional steps required relative to a standard EM sample preparation are cell transfection and a 2- to 45-min staining period with 3,3′-diaminobenzidine (DAB) and hydrogen peroxide (H2O2). PMID:28796234

  19. Generation of a genetically encoded marker of rod photoreceptor outer segment growth and renewal

    John J. Willoughby

    2011-10-01

    Vertebrate photoreceptors are specialized light sensing neurons. The photoreceptor outer segment is a highly modified cilium where photons of light are transduced into a chemical and electrical signal. The outer segment has the typical cilary axoneme but, in addition, it has a large number of densely packed, stacked, intramembranous discs. The molecular and cellular mechanisms that contribute to vertebrate photoreceptor outer segment morphogenesis are still largely unknown. Unlike typical cilia, the outer segment is continuously regenerated or renewed throughout the life of the animal through the combined process of distal outer segment shedding and proximal outer segment growth. The process of outer segment renewal was discovered over forty years ago, but we still lack an understanding of how photoreceptors renew their outer segments and few, if any, molecular mechanisms that regulate outer segment growth or shedding have been described. Our lack of progress in understanding how photoreceptors renew their outer segments has been hampered by the difficulty in measuring rates of renewal. We have created a new method that uses heat-shock induction of a fluorescent protein that can be used to rapidly measure outer segment growth rates. We describe this method, the stable transgenic line we created, and the growth rates observed in larval and adult rod photoreceptors using this new method. This new method will allow us to begin to define the genetic and molecular mechanisms that regulate rod outer segment renewal, a crucial aspect of photoreceptor function and, possibly, viability.

  20. Optimization of a whole-cell biocatalyst by employing genetically encoded product sensors inside nanolitre reactors

    Meyer, Andreas; Pellaux, René; Potot, Sébastien; Becker, Katja; Hohmann, Hans-Peter; Panke, Sven; Held, Martin

    2015-08-01

    Microcompartmentalization offers a high-throughput method for screening large numbers of biocatalysts generated from genetic libraries. Here we present a microcompartmentalization protocol for benchmarking the performance of whole-cell biocatalysts. Gel capsules served as nanolitre reactors (nLRs) for the cultivation and analysis of a library of Bacillus subtilis biocatalysts. The B. subtilis cells, which were co-confined with E. coli sensor cells inside the nLRs, converted the starting material cellobiose into the industrial product vitamin B2. Product formation triggered a sequence of reactions in the sensor cells: (1) conversion of B2 into flavin mononucleotide (FMN), (2) binding of FMN by a RNA riboswitch and (3) self-cleavage of RNA, which resulted in (4) the synthesis of a green fluorescent protein (GFP). The intensity of GFP fluorescence was then used to isolate B. subtilis variants that convert cellobiose into vitamin B2 with elevated efficiency. The underlying design principles of the assay are general and enable the development of similar protocols, which ultimately will speed up the optimization of whole-cell biocatalysts.

  1. Commensal E. coli as an Important Reservoir of Resistance Encoding Genetic Elements

    Azam Mahmoudi-Aznaveh

    2013-11-01

    Full Text Available Background: Diarrheagenic E. coli is the most important cause of diarrhea in children and is a public health concern in developing countries. A major public problem is acquisition and transmission of antimicrobial resistance via mobile genetic elements including plasmids, conjugative transposons, and integrons which may occur through horizontal gene transfer. Objectives: The aim of this study was to investigate the distribution of class 1 and 2 integrons among commensal and enteropathogenic E. coli isolates and assess the role of commensal E. coli population as a reservoir in the acquisition and transmission of antimicrobial resistance. Materials and Methods: Swabs were collected directly from stool samples of the children with diarrhea admitted to three hospitals in Tehran, Iran during July 2012 through October 2012. Antimicrobial susceptibility testing and PCR analysis were performed for analysis of the resistance pattern and integron content of isolates. Results: A total of 20 enteropathogenic E.coli (identified as eae+stx1-stx2- and 20 commensal E.coli were selected for analysis. The resistance pattern in commensal and pathogenic E.coli was very similar. In both groups a high rate of resistance was seen to tetracycline, streptomycin, cotrimoxazole, nalidixic acid, and minocycline. Of 20 EPEC strains, 3 strains (15 % and 1 strain (5% had positive results for int and hep genes, respectively. Among 20 commensal, 65% (13 strains and 10% (2 strains had positive results for int and hep genes, respectively. Conclusions: The higher rate of class 1 integron occurrence among commensal population proposes the commensal intestinal organisms as a potential reservoir of mobile resistance gene elements which could transfer the resistance gene cassettes to other pathogenic and/or nonpathogenic organisms in the intestinal lumen at different occasions.

  2. Construction of a genetically modified wine yeast strain expressing the Aspergillus aculeatus rhaA gene, encoding an -L-Rhamnosidase of enological interest

    Manzanares, P.; Orejas, M.; Vicente Gil, J.; Graaff, de L.H.; Visser, J.; Ramon, D.

    2003-01-01

    The Aspergillus aculeatus rhaA gene encoding an alpha-L-rhamnosidase has been expressed in both laboratory and industrial wine yeast strains. Wines produced in microvinifications, conducted using a combination of the genetically modified industrial strain expressing rhaA and another strain

  3. Response properties of the genetically encoded optical H2O2 sensor HyPer.

    Weller, Jonathan; Kizina, Kathrin M; Can, Karolina; Bao, Guobin; Müller, Michael

    2014-11-01

    Reactive oxygen species mediate cellular signaling and neuropathologies. Hence, there is tremendous interest in monitoring (sub)cellular redox conditions. We evaluated the genetically engineered redox sensor HyPer in mouse hippocampal cell cultures. Two days after lipofection, neurons and glia showed sufficient expression levels, and H2O2 reversibly and dose-dependently increased the fluorescence ratio of cytosolic HyPer. Yet, repeated H2O2 treatment caused progressively declining responses, and with millimolar doses an apparent recovery started while H2O2 was still present. Although HyPer should be H2O2 specific, it seemingly responded also to other oxidants and altered cell-endogenous superoxide production. Control experiments with the SypHer pH sensor confirmed that the HyPer ratio responds to pH changes, decreasing with acidosis and increasing during alkalosis. Anoxia/reoxygenation evoked biphasic HyPer responses reporting apparent reduction/oxidation; replacing Cl(-) exerted only negligible effects. Mitochondria-targeted HyPer readily responded to H2O2-albeit less intensely than cytosolic HyPer. With ratiometric two-photon excitation, H2O2 increased the cytosolic HyPer ratio. Time-correlated fluorescence-lifetime imaging microscopy (FLIM) revealed a monoexponential decay of HyPer fluorescence, and H2O2 decreased fluorescence lifetimes. Dithiothreitol failed to further reduce HyPer or to induce reasonable FLIM and two-photon responses. By enabling dynamic recordings, HyPer is superior to synthetic redox-sensitive dyes. Its feasibility for two-photon excitation also enables studies in more complex preparations. Based on FLIM, quantitative analyses might be possible independent of switching excitation wavelengths. Yet, because of its pronounced pH sensitivity, adaptation to repeated oxidation, and insensitivity to reducing stimuli, HyPer responses have to be interpreted carefully. For reliable data, side-by-side pH monitoring with SypHer is essential. Copyright

  4. Monitoring Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes with Genetically Encoded Calcium and Voltage Fluorescent Reporters

    Shinnawi, Rami; Huber, Irit; Maizels, Leonid; Shaheen, Naim; Gepstein, Amira; Arbel, Gil; Tijsen, Anke J.; Gepstein, Lior

    2015-01-01

    The advent of the human-induced pluripotent stem cell (hiPSC) technology has transformed biomedical research, providing new tools for human disease modeling, drug development, and regenerative medicine. To fulfill its unique potential in the cardiovascular field, efficient methods should be

  5. Method for accurate determination of dissociation constants of optical ratiometric systems: chemical probes, genetically encoded sensors, and interacting molecules.

    Pomorski, Adam; Kochańczyk, Tomasz; Miłoch, Anna; Krężel, Artur

    2013-12-03

    Ratiometric chemical probes and genetically encoded sensors are of high interest for both analytical chemists and molecular biologists. Their high sensitivity toward the target ligand and ability to obtain quantitative results without a known sensor concentration have made them a very useful tool in both in vitro and in vivo assays. Although ratiometric sensors are widely used in many applications, their successful and accurate usage depends on how they are characterized in terms of sensing target molecules. The most important feature of probes and sensors besides their optical parameters is an affinity constant toward analyzed molecules. The literature shows that different analytical approaches are used to determine the stability constants, with the ratio approach being most popular. However, oversimplification and lack of attention to detail results in inaccurate determination of stability constants, which in turn affects the results obtained using these sensors. Here, we present a new method where ratio signal is calibrated for borderline values of intensities of both wavelengths, instead of borderline ratio values that generate errors in many studies. At the same time, the equation takes into account the cooperativity factor or fluorescence artifacts and therefore can be used to characterize systems with various stoichiometries and experimental conditions. Accurate determination of stability constants is demonstrated utilizing four known optical ratiometric probes and sensors, together with a discussion regarding other, currently used methods.

  6. Genetically encoded fluorescent voltage sensors using the voltage-sensing domain of Nematostella and Danio phosphatases exhibit fast kinetics.

    Baker, Bradley J; Jin, Lei; Han, Zhou; Cohen, Lawrence B; Popovic, Marko; Platisa, Jelena; Pieribone, Vincent

    2012-07-15

    A substantial increase in the speed of the optical response of genetically encoded fluorescent protein voltage sensors (FP voltage sensors) was achieved by using the voltage-sensing phosphatase genes of Nematostella vectensis and Danio rerio. A potential N. vectensis voltage-sensing phosphatase was identified in silico. The voltage-sensing domain (S1-S4) of the N. vectensis homolog was used to create an FP voltage sensor called Nema. By replacing the phosphatase with a cerulean/citrine FRET pair, a new FP voltage sensor was synthesized with fast off kinetics (Tau(off)voltage-sensing phosphatase homolog, designated Zahra and Zahra 2, exhibited fast on and off kinetics within 2ms of the time constants observed with the organic voltage-sensitive dye, di4-ANEPPS. Mutagenesis of the S4 region of the Danio FP voltage sensor shifted the voltage dependence to more negative potentials but did not noticeably affect the kinetics of the optical signal. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Genetically-encoded fluorescent voltage sensors using the voltage-sensing domain of Nematostella and Danio phosphatases exhibit fast kinetics

    Baker, Bradley J.; Jin, Lei; Han, Zhou; Cohen, Lawrence B.; Popovic, Marko; Platisa, Jelena; Pieribone, Vincent

    2012-01-01

    A substantial increase in the speed of the optical response of genetically-encoded Fluorescent Protein voltage sensors (FP voltage sensors) was achieved by using the voltage-sensing phosphatase genes of Nematostella vectensis and Danio rerio. A potential N. vectensis voltage-sensing phosphatase was identified in silico. The voltage-sensing domain (S1–S4) of the N. vectensis homolog was used to create an FP voltage sensor called Nema. By replacing the phosphatase with a cerulean/citrine FRET pair, a new FP voltage sensor was synthesized with fast off kinetics (Tauoff voltage-sensing phosphatase homolog, designated Zahra and Zahra 2, exhibited fast on and off kinetics within 2 msec of the time constants observed with the organic voltage-sensitive dye, di4-ANEPPS. Mutagenesis of the S4 region of the Danio FP voltage sensor shifted the voltage dependence to more negative potentials but did not noticeably affect the kinetics of the optical signal. PMID:22634212

  8. Real-time determination of intracellular oxygen in bacteria using a genetically encoded FRET-based biosensor

    Potzkei Janko

    2012-03-01

    Full Text Available Abstract Background Molecular oxygen (O2 is one of the key metabolites of all obligate and facultative aerobic pro- and eukaryotes. It plays a fundamental role in energy homeostasis whereas oxygen deprivation, in turn, broadly affects various physiological and pathophysiological processes. Therefore, real-time monitoring of cellular oxygen levels is basically a prerequisite for the analysis of hypoxia-induced processes in living cells and tissues. Results We developed a genetically encoded Förster resonance energy transfer (FRET-based biosensor allowing the observation of changing molecular oxygen concentrations inside living cells. This biosensor named FluBO (fluorescent protein-based biosensor for oxygen consists of the yellow fluorescent protein (YFP that is sensitive towards oxygen depletion and the hypoxia-tolerant flavin-binding fluorescent protein (FbFP. Since O2 is essential for the formation of the YFP chromophore, efficient FRET from the FbFP donor domain to the YFP acceptor domain only occurs in the presence but not in the absence of oxygen. The oxygen biosensor was used for continuous real-time monitoring of temporal changes of O2 levels in the cytoplasm of Escherichia coli cells during batch cultivation. Conclusions FluBO represents a unique FRET-based oxygen biosensor which allows the non-invasive ratiometric readout of cellular oxygen. Thus, FluBO can serve as a novel and powerful probe for investigating the occurrence of hypoxia and its effects on a variety of (pathophysiological processes in living cells.

  9. Long-term fluorescence lifetime imaging of a genetically encoded sensor for caspase-3 activity in mouse tumor xenografts

    Zherdeva, Victoria; Kazachkina, Natalia I.; Shcheslavskiy, Vladislav; Savitsky, Alexander P.

    2018-03-01

    Caspase-3 is known for its role in apoptosis and programmed cell death regulation. We detected caspase-3 activation in vivo in tumor xenografts via shift of mean fluorescence lifetimes of a caspase-3 sensor. We used the genetically encoded sensor TR23K based on the red fluorescent protein TagRFP and chromoprotein KFP linked by 23 amino acid residues (TagRFP-23-KFP) containing a specific caspase cleavage DEVD motif to monitor the activity of caspase-3 in tumor xenografts by means of fluorescence lifetime imaging-Forster resonance energy transfer. Apoptosis was induced by injection of paclitaxel for A549 lung adenocarcinoma and etoposide and cisplatin for HEp-2 pharynx adenocarcinoma. We observed a shift in lifetime distribution from 1.6 to 1.9 ns to 2.1 to 2.4 ns, which indicated the activation of caspase-3. Even within the same tumor, the lifetime varied presumably due to the tumor heterogeneity and the different depth of tumor invasion. Thus, processing time-resolved fluorescence images allows detection of both the cleaved and noncleaved states of the TR23K sensor in real-time mode during the course of several weeks noninvasively. This approach can be used in drug screening, facilitating the development of new anticancer agents as well as improvement of chemotherapy efficiency and its adaptation for personal treatment.

  10. A New Genetically Encoded Single-Chain Biosensor for Cdc42 Based on FRET, Useful for Live-Cell Imaging

    Cox, Dianne; Hodgson, Louis

    2014-01-01

    Cdc42 is critical in a myriad of cellular morphogenic processes, requiring precisely regulated activation dynamics to affect specific cellular events. To facilitate direct observations of Cdc42 activation in live cells, we developed and validated a new biosensor of Cdc42 activation. The biosensor is genetically encoded, of single-chain design and capable of correctly localizing to membrane compartments as well as interacting with its upstream regulators including the guanine nucleotide dissociation inhibitor. We characterized this new biosensor in motile mouse embryonic fibroblasts and observed robust activation dynamics at leading edge protrusions, similar to those previously observed for endogenous Cdc42 using the organic dye-based biosensor system. We then extended our validations and observations of Cdc42 activity to macrophages, and show that this new biosensor is able to detect differential activation patterns during phagocytosis and cytokine stimulation. Furthermore, we observe for the first time, a highly transient and localized activation of Cdc42 during podosome formation in macrophages, which was previously hypothesized but never directly visualized. PMID:24798463

  11. Clinical characterization of a novel calcium sensing receptor genetic alteration in a Greek patient with autosomal dominant hypocalcemia type 1.

    Papadopoulou, Anna; Gole, Evangelia; Melachroinou, Katerina; Trangas, Theoni; Bountouvi, Evaggelia; Papadimitriou, Anastasios

    2017-04-01

    Autosomal dominant hypocalcemia (ADH) is a rare familial or sporadic syndrome associated with activating mutations in the calcium sensing receptor (CaSR) gene. The aim of this study was to assess the functional significance of a novel CaSR mutation and, moreover, to present the clinical characteristics and the bone mineral density (BMD) progression from early childhood to late puberty in a patient with ADH. Genetic analysis of the CaSR gene was performed in a patient who presented in the neonatal period with hypocalcemic seizures and biochemical features of ADH. The functional impact of the novel mutation identified was assessed in cultured HEK 293T cells, transfected with either the wild type (WT) or mutant CaSR, by evaluating intracellular calcium ([Ca2+]i) influx after stimulation with extracellular calcium (Ca2+). Several BMD measurements were performed during the patient's follow-up until late puberty. A novel CaSR mutation (p.L123S) was identified, which, as demonstrated by functional analysis, renders CaSR more sensitive to extracellular changes of Ca2+ compared with the WT, although the difference is not statistically significant. BMD measurements, from early childhood to late puberty, revealed high normal to elevated BMD. We present the first Greek patient, to our knowledge, with sporadic ADH due to a novel gain-of-function mutation of the CaSR gene.

  12. Multiparameter imaging of calcium and abscisic acid and high-resolution quantitative calcium measurements using R-GECO1-mTurquoise in Arabidopsis.

    Waadt, Rainer; Krebs, Melanie; Kudla, Jörg; Schumacher, Karin

    2017-10-01

    Calcium signals occur in specific spatio-temporal patterns in response to various stimuli and are coordinated with, for example, hormonal signals, for physiological and developmental adaptations. Quantification of calcium together with other signalling molecules is required for correlative analyses and to decipher downstream calcium-decoding mechanisms. Simultaneous in vivo imaging of calcium and abscisic acid has been performed here to investigate the interdependence of the respective signalling processes in Arabidopsis thaliana roots. Advanced ratiometric genetically encoded calcium indicators have been generated and in vivo calcium calibration protocols were established to determine absolute calcium concentration changes in response to auxin and ATP. In roots, abscisic acid induced long-term basal calcium concentration increases, while auxin triggered rapid signals in the elongation zone. The advanced ratiometric calcium indicator R-GECO1-mTurquoise exhibited an increased calcium signal resolution compared to commonly used Förster resonance energy transfer-based indicators. Quantitative calcium measurements in Arabidopsis root tips using R-GECO1-mTurquoise revealed detailed maps of absolute calcium concentration changes in response to auxin and ATP. Calcium calibration protocols using R-GECO1-mTurquoise enabled high-resolution quantitative imaging of resting cytosolic calcium concentrations and their dynamic changes that revealed distinct hormonal and ATP responses in roots. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  13. Live imaging of intra- and extracellular pH in plants using pHusion, a novel genetically encoded biosensor

    Gjetting, Kisten Sisse Krag; Ytting, Cecilie Karkov; Schulz, Alexander; Fuglsang, Anja Thoe

    2012-01-01

    Changes in pH are now widely accepted as a signalling mechanism in cells. In plants, proton pumps in the plasma membrane and tonoplast play a key role in regulation of intracellular pH homeostasis and maintenance of transmembrane proton gradients. Proton transport in response to external stimuli can be expected to be finely regulated spatially and temporally. With the ambition to follow such changes live, a new genetically encoded sensor, pHusion, has been developed. pHusion is especially designed for apoplastic pH measurements. It was constitutively expressed in Arabidopsis and targeted for expression in either the cytosol or the apoplast including intracellular compartments. pHusion consists of the tandem concatenation of enhanced green fluorescent protein (EGFP) and monomeric red fluorescent protein (mRFP1), and works as a ratiometric pH sensor. Live microscopy at high spatial and temporal resolution is highly dependent on appropriate immobilization of the specimen for microscopy. Medical adhesive often used in such experiments destroys cell viability in roots. Here a novel system for immobilizing Arabidopsis seedling roots for perfusion experiments is presented which does not impair cell viability. With appropriate immobilization, it was possible to follow changes of the apoplastic and cytosolic pH in mesophyll and root tissue. Rapid pH homeostasis upon external pH changes was reflected by negligible cytosolic pH fluctuations, while the apoplastic pH changed drastically. The great potential for analysing pH regulation in a whole-tissue, physiological context is demonstrated by the immediate alkalinization of the subepidermal apoplast upon external indole-3-acetic acid administration. This change is highly significant in the elongation zone compared with the root hair zone and control roots. PMID:22407646

  14. Live imaging of intra- and extracellular pH in plants using pHusion, a novel genetically encoded biosensor.

    Gjetting, Kisten Sisse Krag; Ytting, Cecilie Karkov; Schulz, Alexander; Fuglsang, Anja Thoe

    2012-05-01

    Changes in pH are now widely accepted as a signalling mechanism in cells. In plants, proton pumps in the plasma membrane and tonoplast play a key role in regulation of intracellular pH homeostasis and maintenance of transmembrane proton gradients. Proton transport in response to external stimuli can be expected to be finely regulated spatially and temporally. With the ambition to follow such changes live, a new genetically encoded sensor, pHusion, has been developed. pHusion is especially designed for apoplastic pH measurements. It was constitutively expressed in Arabidopsis and targeted for expression in either the cytosol or the apoplast including intracellular compartments. pHusion consists of the tandem concatenation of enhanced green fluorescent protein (EGFP) and monomeric red fluorescent protein (mRFP1), and works as a ratiometric pH sensor. Live microscopy at high spatial and temporal resolution is highly dependent on appropriate immobilization of the specimen for microscopy. Medical adhesive often used in such experiments destroys cell viability in roots. Here a novel system for immobilizing Arabidopsis seedling roots for perfusion experiments is presented which does not impair cell viability. With appropriate immobilization, it was possible to follow changes of the apoplastic and cytosolic pH in mesophyll and root tissue. Rapid pH homeostasis upon external pH changes was reflected by negligible cytosolic pH fluctuations, while the apoplastic pH changed drastically. The great potential for analysing pH regulation in a whole-tissue, physiological context is demonstrated by the immediate alkalinization of the subepidermal apoplast upon external indole-3-acetic acid administration. This change is highly significant in the elongation zone compared with the root hair zone and control roots.

  15. Genetic encoding of a bicyclo[6.1.0]nonyne-charged amino acid enables fast cellular protein imaging by metal-free ligation.

    Borrmann, Annika; Milles, Sigrid; Plass, Tilman; Dommerholt, Jan; Verkade, Jorge M M; Wiessler, Manfred; Schultz, Carsten; van Hest, Jan C M; van Delft, Floris L; Lemke, Edward A

    2012-09-24

    Visualizing biomolecules by fluorescent tagging is a powerful method for studying their behaviour and function inside cells. We prepared and genetically encoded an unnatural amino acid (UAA) that features a bicyclononyne moiety. This UAA offered exceptional reactivity in strain-promoted azide-alkyne cycloadditions. Kinetic measurements revealed that the UAA reacted also remarkably fast in the inverse-electron-demand Diels-Alder cycloaddition with tetrazine-conjugated dyes. Genetic encoding of the new UAA inside mammalian cells and its subsequent selective labeling at low dye concentrations demonstrate the usefulness of the new amino acid for future imaging studies. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Utilisation of ISA Reverse Genetics and Large-Scale Random Codon Re-Encoding to Produce Attenuated Strains of Tick-Borne Encephalitis Virus within Days.

    de Fabritus, Lauriane; Nougairède, Antoine; Aubry, Fabien; Gould, Ernest A; de Lamballerie, Xavier

    2016-01-01

    Large-scale codon re-encoding is a new method of attenuating RNA viruses. However, the use of infectious clones to generate attenuated viruses has inherent technical problems. We previously developed a bacterium-free reverse genetics protocol, designated ISA, and now combined it with large-scale random codon-re-encoding method to produce attenuated tick-borne encephalitis virus (TBEV), a pathogenic flavivirus which causes febrile illness and encephalitis in humans. We produced wild-type (WT) and two re-encoded TBEVs, containing 273 or 273+284 synonymous mutations in the NS5 and NS5+NS3 coding regions respectively. Both re-encoded viruses were attenuated when compared with WT virus using a laboratory mouse model and the relative level of attenuation increased with the degree of re-encoding. Moreover, all infected animals produced neutralizing antibodies. This novel, rapid and efficient approach to engineering attenuated viruses could potentially expedite the development of safe and effective new-generation live attenuated vaccines.

  17. a permutation encoding te algorithm solution of reso tation encoding

    eobe

    Keywords: Genetic algorithm, resource constrained. 1. INTRODUCTION. 1. .... Nigerian Journal of Technology. Vol. 34, No. 1, January 2015. 128 ... 4. ENCODING OF CHROMOSOME. ENCODING OF CHROMOSOME .... International Multi conference of Engineers and ... method”, Naval Research Logistics, vol 48, issue 2,.

  18. Genetically encoded pH-indicators reveal activity-dependent cytosolic acidification of Drosophila motor nerve termini in vivo

    Rossano, Adam J; Chouhan, Amit K; Macleod, Gregory T

    2013-01-01

    All biochemical processes, including those underlying synaptic function and plasticity, are pH sensitive. Cytosolic pH (pHcyto) shifts are known to accompany nerve activity in situ, but technological limitations have prevented characterization of such shifts in vivo. Genetically encoded pH-indicators (GEpHIs) allow for tissue-specific in vivo measurement of pH. We expressed three different GEpHIs in the cytosol of Drosophila larval motor neurons and observed substantial presynaptic acidification in nerve termini during nerve stimulation in situ. SuperEcliptic pHluorin was the most useful GEpHI for studying pHcyto shifts in this model system. We determined the resting pH of the nerve terminal cytosol to be 7.30 ± 0.02, and observed a decrease of 0.16 ± 0.01 pH units when the axon was stimulated at 40 Hz for 4 s. Realkalinization occurred upon cessation of stimulation with a time course of 20.54 ± 1.05 s (τ). The chemical pH-indicator 2′,7′-bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein corroborated these changes in pHcyto. Bicarbonate-derived buffering did not contribute to buffering of acid loads from short (≤4 s) trains of action potentials but did buffer slow (∼60 s) acid loads. The magnitude of cytosolic acid transients correlated with cytosolic Ca2+ increase upon stimulation, and partial inhibition of the plasma membrane Ca2+-ATPase, a Ca2+/H+ exchanger, attenuated pHcyto shifts. Repeated stimulus trains mimicking motor patterns generated greater cytosolic acidification (∼0.30 pH units). Imaging through the cuticle of intact larvae revealed spontaneous pHcyto shifts in presynaptic termini in vivo, similar to those seen in situ during fictive locomotion, indicating that presynaptic pHcyto shifts cannot be dismissed as artifacts of ex vivo preparations. PMID:23401611

  19. Expression and testing in plants of ArcLight, a genetically-encoded voltage indicator used in neuroscience research.

    Matzke, Antonius J M; Matzke, Marjori

    2015-10-12

    It is increasingly appreciated that electrical controls acting at the cellular and supra-cellular levels influence development and initiate rapid responses to environmental cues. An emerging method for non-invasive optical imaging of electrical activity at cell membranes uses genetically-encoded voltage indicators (GEVIs). Developed by neuroscientists to chart neuronal circuits in animals, GEVIs comprise a fluorescent protein that is fused to a voltage-sensing domain. One well-known GEVI, ArcLight, undergoes strong shifts in fluorescence intensity in response to voltage changes in mammalian cells. ArcLight consists of super-ecliptic (SE) pHluorin (pH-sensitive fluorescent protein) with an A227D substitution, which confers voltage sensitivity in neurons, fused to the voltage-sensing domain of the voltage-sensing phosphatase of C iona i ntestinalis (Ci-VSD). In an ongoing effort to adapt tools of optical electrophysiology for plants, we describe here the expression and testing of ArcLight and various derivatives in different membranes of root cells in Arabidopsis thaliana. Transgenic constructs were designed to express ArcLight and various derivatives targeted to the plasma membrane and nuclear membranes of Arabidopsis root cells. In transgenic seedlings, changes in fluorescence intensity of these reporter proteins following extracellular ATP (eATP) application were monitored using a fluorescence microscope equipped with a high speed camera. Coordinate reductions in fluorescence intensity of ArcLight and Ci-VSD-containing derivatives were observed at both the plasma membrane and nuclear membranes following eATP treatments. However, similar responses were observed for derivatives lacking the Ci-VSD. The dispensability of the Ci-VSD suggests that in plants, where H(+) ions contribute substantially to electrical activities, the voltage-sensing ability of ArcLight is subordinate to the pH sensitivity of its SEpHluorin base. The transient reduction of Arc

  20. Genetic polymorphisms in calcitonin receptor gene and risk for recurrent kidney calcium stone disease.

    Shakhssalim, Nasser; Basiri, Abbas; Houshmand, Massoud; Pakmanesh, Hamid; Golestan, Banafsheh; Azadvari, Mohaddeseh; Aryan, Hajar; Kashi, Amir H

    2014-01-01

    In this study the full sequence of the calcitonin receptor gene (CALCR) in a group of Iranian males suffering from recurrent calcium urinary stones was compared with that of a control group. Serum and urinary biochemistry related to urolithiasis were evaluated in 105 males diagnosed with recurrent kidney calcium stones and 101 age-matched healthy control males. The polymerase chain reaction single-strand conformation polymorphism method was used to detect new polymorphisms in the CALCR. Nine polymorphisms were detected; seven were in the non-coding and two in the coding region. The T allele associated with the 3'UTR+18C>T polymorphism was observed exclusively in the stone formers. The exact odds ratio for the T allele in this locus for those at risk of stone formation was 36.72 (95% CI 4.95-272.0) (p C and IVS1insA polymorphisms in intron 1 were associated with kidney stone disease (p T and intron 1 polymorphisms in the CALCR and the risk of kidney stone disease. 2013 S. Karger AG, Basel.

  1. Genetic parameters of calcium, phosphorus, magnesium, and potassium serum concentrations during the first 8 days after calving in Holstein cows.

    Tsiamadis, V; Banos, G; Panousis, N; Kritsepi-Konstantinou, M; Arsenos, G; Valergakis, G E

    2016-07-01

    Calcium, Mg, P, and K are of great importance for the health and productivity of dairy cows after calving. So far genetic studies have focused on clinical hypocalcemia, leaving the genetic parameters of these macroelements unstudied. Our objective was to estimate the genetic parameters of Ca, Mg, P, and K serum concentrations and their changes during the first 8d after calving. The study was conducted in 9 herds located in northern Greece, with 1,021 Holstein cows enrolled from November 2010 until November 2012. No herd used any kind of preventive measures for hypocalcemia. Pedigree information for all cows was available. A total of 35 cows were diagnosed and treated for periparturient paresis and, therefore, excluded from the study. The remaining 986 cows were included in genetic analysis. The distribution of cows across parities was 459 (parity 1), 234 (parity 2), 158 (parity 3), and 135 (parity ≥4). A sample of blood was taken from each cow on d1, 2, 4, and 8 after calving and serum concentrations of Ca, P, Mg, and K were measured in each sample. A final data set of 15,390 biochemical records was created consisting of 3,903 Ca, 3,902 P, 3,903Mg, and 3,682K measurements. Moreover, changes of these concentrations between d1 and 4 as well as 1 and 8 after calving were calculated and treated as different traits. Random regression models were used to analyze the data. Results showed that daily heritabilities of Ca, P, and Mg concentrations traits were moderate to high (0.20-0.43), whereas those of K were low to moderate (0.12-0.23). Regarding concentration changes, only Mg change between d1 and 8 after calving had a significant heritability of 0.18. Genetic correlations between Ca, P, Mg, and K concentrations and their concentration changes from d1 to 4 and 1 to 8 after calving were not significantly different from zero. Most phenotypic correlations among Ca, P, Mg, and K concentrations were positive and low (0.09-0.16), whereas the correlation between P and Mg was

  2. Intracellular pH imaging in cancer cells in vitro and tumors in vivo using the new genetically encoded sensor SypHer2.

    Shirmanova, Marina V; Druzhkova, Irina N; Lukina, Maria M; Matlashov, Mikhail E; Belousov, Vsevolod V; Snopova, Ludmila B; Prodanetz, Natalia N; Dudenkova, Varvara V; Lukyanov, Sergey A; Zagaynova, Elena V

    2015-09-01

    Measuring intracellular pH (pHi) in tumors is essential for the monitoring of cancer progression and the response of cancer cells to various treatments. The purpose of the study was to develop a method for pHi mapping in living cancer cells in vitro and in tumors in vivo, using the novel genetically encoded indicator, SypHer2. A HeLa Kyoto cell line stably expressing SypHer2 in the cytoplasm was used, to perform ratiometric (dual excitation) imaging of the probe in cell culture, in 3D tumor spheroids and in tumor xenografts in living mice. Using SypHer2, pHi was demonstrated to be 7.34±0.11 in monolayer HeLa cells in vitro under standard cultivation conditions. An increasing pHi gradient from the center to the periphery of the spheroids was displayed. We obtained fluorescence ratio maps for HeLa tumors in vivo and ex vivo. Comparison of the map with the pathomorphology and with hypoxia staining of the tumors revealed a correspondence of the zones with higher pHi to the necrotic and hypoxic areas. Our results demonstrate that pHi imaging with the genetically encoded pHi indicator, SypHer2, can be a valuable tool for evaluating tumor progression in xenograft models. We have demonstrated, for the first time, the possibility of using the genetically encoded sensor SypHer2 for ratiometric pH imaging in cancer cells in vitro and in tumors in vivo. SypHer2 shows great promise as an instrument for pHi monitoring able to provide high accuracy and spatiotemporal resolution. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Visualization of Plasticity in Fear-Evoked Calcium Signals in Midbrain Dopamine Neurons

    Gore, Bryan B.; Soden, Marta E.; Zweifel, Larry S.

    2014-01-01

    Dopamine is broadly implicated in fear-related processes, yet we know very little about signaling dynamics in these neurons during active fear conditioning. We describe the direct imaging of calcium signals of dopamine neurons during Pavlovian fear conditioning using fiber-optic confocal microscopy coupled with the genetically encoded calcium…

  4. cDNAs encoding [D-Ala2]deltorphin precursors from skin of Phyllomedusa bicolor also contain genetic information for three dermorphin-related opioid peptides.

    Richter, K; Egger, R; Negri, L; Corsi, R; Severini, C; Kreil, G

    1990-01-01

    We present the structure of four precursors for [D-Ala2]deltorphins I and II as deduced from cDNAs cloned from skin of the frog Phyllomedusa bicolor. These contain the genetic information for one copy of [D-Ala2]deltorphin II and zero, one, or three copies of [D-Ala2]deltorphin I. In each case, the D-alanine of the end product is encoded by a normal GCG codon for L-alanine. In addition, the existence of three peptides related to dermorphin was predicted from the amino acid sequence of the pre...

  5. Genetics and Molecular Biology of Epstein-Barr Virus-Encoded BART MicroRNA: A Paradigm for Viral Modulation of Host Immune Response Genes and Genome Stability

    David H. Dreyfus

    2017-01-01

    Full Text Available Epstein-Barr virus, a ubiquitous human herpesvirus, is associated through epidemiologic evidence with common autoimmune syndromes and cancers. However, specific genetic mechanisms of pathogenesis have been difficult to identify. In this review, the author summarizes evidence that recently discovered noncoding RNAs termed microRNA encoded by Epstein-Barr virus BARF (BamHI A right frame termed BART (BamHI A right transcripts are modulators of human immune response genes and genome stability in infected and bystander cells. BART expression is apparently regulated by complex feedback loops with the host immune response regulatory NF-κB transcription factors. EBV-encoded BZLF-1 (ZEBRA protein could also regulate BART since ZEBRA contains a terminal region similar to ankyrin proteins such as IκBα that regulate host NF-κB. BALF-2 (BamHI A left frame transcript, a viral homologue of the immunoglobulin and T cell receptor gene recombinase RAG-1 (recombination-activating gene-1, may also be coregulated with BART since BALF-2 regulatory sequences are located near the BART locus. Viral-encoded microRNA and viral mRNA transferred to bystander cells through vesicles, defective viral particles, or other mechanisms suggest a new paradigm in which bystander or hit-and-run mechanisms enable the virus to transiently or chronically alter human immune response genes as well as the stability of the human genome.

  6. Towards PDT with Genetically Encoded Photosensitizer KillerRed: A Comparison of Continuous and Pulsed Laser Regimens in an Animal Tumor Model.

    Marina Shirmanova

    Full Text Available The strong phototoxicity of the red fluorescent protein KillerRed allows it to be considered as a potential genetically encoded photosensitizer for the photodynamic therapy (PDT of cancer. The advantages of KillerRed over chemical photosensitizers are its expression in tumor cells transduced with the appropriate gene and direct killing of cells through precise damage to any desired cell compartment. The ability of KillerRed to affect cell division and to induce cell death has already been demonstrated in cancer cell lines in vitro and HeLa tumor xenografts in vivo. However, the further development of this approach for PDT requires optimization of the method of treatment. In this study we tested the continuous wave (593 nm and pulsed laser (584 nm, 10 Hz, 18 ns modes to achieve an antitumor effect. The research was implemented on CT26 subcutaneous mouse tumors expressing KillerRed in fusion with histone H2B. The results showed that the pulsed mode provided a higher rate of photobleaching of KillerRed without any temperature increase on the tumor surface. PDT with the continuous wave laser was ineffective against CT26 tumors in mice, whereas the pulsed laser induced pronounced histopathological changes and inhibition of tumor growth. Therefore, we selected an effective regimen for PDT when using the genetically encoded photosensitizer KillerRed and pulsed laser irradiation.

  7. Noradrenergic mechanisms and high blood pressure maintenance in genetic hypertension: The role of Gi proteins and voltage-dependent calcium channels

    Zicha, Josef; Pintérová, Mária; Líšková, Silvia; Dobešová, Zdenka; Kuneš, Jaroslav

    2007-01-01

    Roč. 29, č. 4 (2007), s. 229-229 ISSN 1064-1963. [International symposium on SHR /12./. 20.10.2006-21.10.2006, Kyoto] R&D Projects: GA MZd(CZ) NR7786 Institutional research plan: CEZ:AV0Z50110509 Keywords : genetic hypertension * noradrenergic mechanisms * Gi proteins * voltage-dependent calcium channels Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  8. Genetic association analysis of 13 nuclear-encoded mitochondrial candidate genes with type II diabetes mellitus: The DAMAGE study

    Reiling, Erwin; van Vliet-Ostaptchouk, Jana V; van 't Riet, Esther

    2009-01-01

    ). After a meta-analysis, only one SNP in SIRT4 (rs2522138) remained significant (P=0.01). Extending the second stage with samples from the Danish Steno Study (n=1220 participants) resulted in a common odds ratio (OR) of 0.92 (0.85-1.00), P=0.06. Moreover, in a large meta-analysis of three genome......Mitochondria play an important role in many processes, like glucose metabolism, fatty acid oxidation and ATP synthesis. In this study, we aimed to identify association of common polymorphisms in nuclear-encoded genes involved in mitochondrial protein synthesis and biogenesis with type II diabetes...

  9. Mapping the Binding Site for Escitalopram and Paroxetine in the Human Serotonin Transporter Using Genetically Encoded Photo-Cross-Linkers

    Rannversson, Hafsteinn; Andersen, Jacob; Bang-Andersen, Benny

    2017-01-01

    amber codon suppression in hSERT to encode the photo-cross-linking unnatural amino acid p-azido-l-phenylalanine into the suggested high- and low-affinity binding sites. We then employ UV-induced cross-linking with azF to map the binding site of escitalopram and paroxetine, two prototypical selective...... serotonin reuptake inhibitors (SSRIs). We find that the two antidepressant drugs exclusively cross-link to azF incorporated at the high-affinity binding site of hSERT, while cross-linking is not observed at the low-affinity binding site. Combined with previous homology models and recent structural data on h...

  10. Local adaptations in bryophytes revisited: the genetic structure of the calcium-tolerant peatmoss Sphagnum warnstorfii along geographic and pH gradients

    Mikulášková, Eva; Hájek, Michal; Veleba, Adam; Johnson, Matthew G; Hájek, Tomáš; Shaw, Jonathan A

    2015-01-01

    Bryophytes dominate some ecosystems despite their extraordinary sensitivity to habitat quality. Nevertheless, some species behave differently across various regions. The existence of local adaptations is questioned by a high dispersal ability, which is thought to redistribute genetic variability among populations. Although Sphagnum warnstorfii is an important ecosystem engineer in fen peatlands, the causes of its rather wide niche along the pH/calcium gradient are poorly understood. Here, we studied the genetic variability of its global populations, with a detailed focus on the wide pH/calcium gradient in Central Europe. Principal coordinates analysis of 12 polymorphic microsatellite loci revealed a significant gradient coinciding with water pH, but independent of geography; even samples from the same fens were clearly separated along this gradient. However, most of the genetic variations remained unexplained, possibly because of the introgression from phylogenetically allied species. This explanation is supported by the small heterogeneous cluster of samples that appeared when populations morphologically transitional to S. subnites, S. rubellum, or S. russowii were included into the analysis. Alternatively, this unexplained variation might be attributed to a legacy of glacial refugia with recently dissolved ecological and biogeographic consequences. Isolation by distance appeared at the smallest scale only (up to 43 km). Negative spatial correlations occurred more frequently, mainly at long distances (up to 950 km), implying a genetic similarity among samples which are very distant geographically. Our results confirm the high dispersal ability of peatmosses, but simultaneously suggested that their ability to cope with a high pH/calcium level is at least partially determined genetically, perhaps via specific physiological mechanisms or a hummock-forming ability. PMID:25628880

  11. Long-term correction of obesity and diabetes in genetically obese mice by a single intramuscular injection of recombinant adeno-associated virus encoding mouse leptin

    Murphy, John E.; Zhou, Shangzhen; Giese, Klaus; Williams, Lewis T.; Escobedo, Jaime A.; Dwarki, Varavani J.

    1997-01-01

    The ob/ob mouse is genetically deficient in leptin and exhibits a phenotype that includes obesity and non-insulin-dependent diabetes melitus. This phenotype closely resembles the morbid obesity seen in humans. In this study, we demonstrate that a single intramuscular injection of a recombinant adeno-associated virus (AAV) vector encoding mouse leptin (rAAV-leptin) in ob/ob mice leads to prevention of obesity and diabetes. The treated animals show normalization of metabolic abnormalities including hyperglycemia, insulin resistance, impaired glucose tolerance, and lethargy. The effects of a single injection have lasted through the 6-month course of the study. At all time points measured the circulating levels of leptin in the serum were similar to age-matched control C57 mice. These results demonstrate that maintenance of normal levels of leptin (2–5 ng/ml) in the circulation can prevent both the onset of obesity and associated non-insulin-dependent diabetes. Thus a single injection of a rAAV vector expressing a therapeutic gene can lead to complete and long-term correction of a genetic disorder. Our study demonstrates the long-term correction of a disease caused by a genetic defect and proves the feasibility of using rAAV-based vectors for the treatment of chronic disorders like obesity. PMID:9391128

  12. cDNAs encoding [D-Ala2]deltorphin precursors from skin of Phyllomedusa bicolor also contain genetic information for three dermorphin-related opioid peptides.

    Richter, K; Egger, R; Negri, L; Corsi, R; Severini, C; Kreil, G

    1990-06-01

    We present the structure of four precursors for [D-Ala2]deltorphins I and II as deduced from cDNAs cloned from skin of the frog Phyllomedusa bicolor. These contain the genetic information for one copy of [D-Ala2]deltorphin II and zero, one, or three copies of [D-Ala2]deltorphin I. In each case, the D-alanine of the end product is encoded by a normal GCG codon for L-alanine. In addition, the existence of three peptides related to dermorphin was predicted from the amino acid sequence of the precursors. These peptides were synthesized with a D-alanine in position 2 and their pharmacological properties were tested. Two of them, [Lys7]dermorphin-OH and [Trp4,Asn7]dermorphin-OH, were found to have roughly the same affinity and selectivity for mu-type opioid receptors as dermorphin.

  13. Genetic variations of VDR/NR1I1 encoding vitamin D receptor in a Japanese population.

    Ukaji, Maho; Saito, Yoshiro; Fukushima-Uesaka, Hiromi; Maekawa, Keiko; Katori, Noriko; Kaniwa, Nahoko; Yoshida, Teruhiko; Nokihara, Hiroshi; Sekine, Ikuo; Kunitoh, Hideo; Ohe, Yuichiro; Yamamoto, Noboru; Tamura, Tomohide; Saijo, Nagahiro; Sawada, Jun-ichi

    2007-12-01

    The vitamin D receptor (VDR) is a transcriptional factor responsive to 1alpha,25-dihydroxyvitamin D(3) and lithocholic acid, and induces expression of drug metabolizing enzymes CYP3A4, CYP2B6 and CYP2C9. In this study, the promoter regions, 14 exons (including 6 exon 1's) and their flanking introns of VDR were comprehensively screened for genetic variations in 107 Japanese subjects. Sixty-one genetic variations including 25 novel ones were found: 9 in the 5'-flanking region, 2 in the 5'-untranslated region (UTR), 7 in the coding exons (5 synonymous and 2 nonsynonymous variations), 12 in the 3'-UTR, 19 in the introns between the exon 1's, and 12 in introns 2 to 8. Of these, one novel nonsynonymous variation, 154A>G (Met52Val), was detected with an allele frequency of 0.005. The single nucleotide polymorphisms (SNPs) that increase VDR expression or activity, -29649G>A, 2T>C and 1592((*)308)C>A tagging linked variations in the 3'-UTR, were detected at 0.430, 0.636, and 0.318 allele frequencies, respectively. Another SNP, -26930A>G, with reduced VDR transcription was found at a 0.028 frequency. These findings would be useful for association studies on VDR variations in Japanese.

  14. Basal and Activated Calcium Sensitization Mediated by RhoA/Rho Kinase Pathway in Rats with Genetic and Salt Hypertension

    Behuliak, Michal; Bencze, Michal; Vaněčková, Ivana; Kuneš, Jaroslav; Zicha, Josef

    2017-01-01

    Roč. 2017, January (2017), č. článku 8029728. ISSN 2314-6133 R&D Projects: GA ČR(CZ) GP14-16225P; GA MZd(CZ) NV15-25396A Institutional support: RVO:67985823 Keywords : calcium sensitization * RhoA/Rho kinase * fasudil * calcium influx * nifedipine * BAY K8644 Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery OBOR OECD: Cardiac and Cardiovascular systems Impact factor: 2.476, year: 2016

  15. The T-type calcium channel antagonist Z944 rescues impairments in crossmodal and visual recognition memory in Genetic Absence Epilepsy Rats from Strasbourg.

    Marks, Wendie N; Cain, Stuart M; Snutch, Terrance P; Howland, John G

    2016-10-01

    Childhood absence epilepsy (CAE) is often comorbid with behavioral and cognitive symptoms, including impaired visual memory. Genetic Absence Epilepsy Rats from Strasbourg (GAERS) is an animal model closely resembling CAE; however, cognition in GAERS is poorly understood. Crossmodal object recognition (CMOR) is a recently developed memory task that examines not only purely visual and tactile memory, but also requires rodents to integrate sensory information about objects gained from tactile exploration to enable visual recognition. Both the visual and crossmodal variations of the CMOR task rely on the perirhinal cortex, an area with dense expression of T-type calcium channels. GAERS express a gain-in-function missense mutation in the Cav3.2 T-type calcium channel gene. Therefore, we tested whether the T-type calcium channel blocker Z944 dose dependently (1, 3, 10mg/kg; i.p.) altered CMOR memory in GAERS compared to the non-epileptic control (NEC) strain. GAERS demonstrated recognition memory deficits in the visual and crossmodal variations of the CMOR task that were reversed by the highest dose of Z944. Electroencephalogram recordings determined that deficits in CMOR memory in GAERS were not the result of seizures during task performance. In contrast, NEC showed a decrease in CMOR memory following Z944 treatment. These findings suggest that T-type calcium channels mediate CMOR in both the GAERS and NEC strains. Future research into the therapeutic potential of T-type calcium channel regulation may be particularly fruitful for the treatment of CAE and other disorders characterized by visual memory deficits. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Partitioning of genetic variation between regulatory and coding gene segments: the predominance of software variation in genes encoding introvert proteins.

    Mitchison, A

    1997-01-01

    In considering genetic variation in eukaryotes, a fundamental distinction can be made between variation in regulatory (software) and coding (hardware) gene segments. For quantitative traits the bulk of variation, particularly that near the population mean, appears to reside in regulatory segments. The main exceptions to this rule concern proteins which handle extrinsic substances, here termed extrovert proteins. The immune system includes an unusually large proportion of this exceptional category, but even so its chief source of variation may well be polymorphism in regulatory gene segments. The main evidence for this view emerges from genome scanning for quantitative trait loci (QTL), which in the case of the immune system points to a major contribution of pro-inflammatory cytokine genes. Further support comes from sequencing of major histocompatibility complex (Mhc) class II promoters, where a high level of polymorphism has been detected. These Mhc promoters appear to act, in part at least, by gating the back-signal from T cells into antigen-presenting cells. Both these forms of polymorphism are likely to be sustained by the need for flexibility in the immune response. Future work on promoter polymorphism is likely to benefit from the input from genome informatics.

  17. Fluorescence-based characterization of genetically encoded peptides that fold in live cells: progress toward a generic hairpin scaffold

    Cheng, Zihao; Campbell, Robert E.

    2007-02-01

    Binding proteins suitable for expression and high affinity molecular recognition in the cytoplasm or nucleus of live cells have numerous applications in the biological sciences. In an effort to add a new minimal motif to the growing repertoire of validated non-immunoglobulin binding proteins, we have undertaken the development of a generic protein scaffold based on a single β-hairpin that can fold efficiently in the cytoplasm. We have developed a method, based on the measurement of fluorescence resonance energy transfer (FRET) between a genetically fused cyan fluorescent protein (CFP) and yellow fluorescent protein (YFP), that allows the structural stability of recombinant β-hairpin peptides to be rapidly assessed both in vitro and in vivo. We have previously reported the validation of this method when applied to a 16mer tryptophan zipper β-hairpin. We now describe the use of this method to evaluate the potential of a designed 20mer β-hairpin peptide with a 3rd Trp/Trp cross-strand pair to function as a generic protein scaffold. Quantitative analysis of the FRET efficiency, resistance to proteolysis (assayed by loss of FRET), and circular dichroism spectra revealed that the 20mer peptide is significantly more tolerant of destabilizing mutations than the 16mer peptide. Furthermore, we experimentally demonstrate that the in vitro determined β-hairpin stabilities are well correlated with in vivo β-hairpin stabilities as determined by FRET measurements of colonies of live bacteria expressing the recombinant peptides flanked by CFP and YFP. Finally, we report on our progress to develop highly folded 24mer and 28mer β-hairpin peptides through the use of fluorescence-based library screening.

  18. Displacement encoder

    Hesketh, T.G.

    1983-01-01

    In an optical encoder, light from an optical fibre input A is encoded by means of the encoding disc and is subsequently collected for transmission via optical fibre B. At some point in the optical path between the fibres A and B, the light is separated into component form by means of a filtering or dispersive system and each colour component is associated with a respective one of the coding channels of the disc. In this way, the significance of each bit of the coded information is represented by a respective colour thereby enabling the components to be re-combined for transmission by the fibre B without loss of information. (author)

  19. The genetic background affects the vascular response in T-type calcium channels 3.2 deficient mice

    Svenningsen, Per; Hansen, Pernille B L

    2016-01-01

    -type channels are the dominant Ca(2+) entry pathway in vascular smooth muscle cells, however, T-type calcium channels are also expressed in the cardiovascular system where they play a functional role in the regulation of both contraction and vasodilation in (Chen et al. 2003; Hansen et al. 2001). This article...... is protected by copyright. All rights reserved....

  20. Long-term In Vivo Calcium Imaging of Astrocytes Reveals Distinct Cellular Compartment Responses to Sensory Stimulation.

    Stobart, Jillian L; Ferrari, Kim David; Barrett, Matthew J P; Stobart, Michael J; Looser, Zoe J; Saab, Aiman S; Weber, Bruno

    2018-01-01

    Localized, heterogeneous calcium transients occur throughout astrocytes, but the characteristics and long-term stability of these signals, particularly in response to sensory stimulation, remain unknown. Here, we used a genetically encoded calcium indicator and an activity-based image analysis scheme to monitor astrocyte calcium activity in vivo. We found that different subcellular compartments (processes, somata, and endfeet) displayed distinct signaling characteristics. Closer examination of individual signals showed that sensory stimulation elevated the number of specific types of calcium peaks within astrocyte processes and somata, in a cortical layer-dependent manner, and that the signals became more synchronous upon sensory stimulation. Although mice genetically lacking astrocytic IP3R-dependent calcium signaling (Ip3r2-/-) had fewer signal peaks, the response to sensory stimulation was sustained, suggesting other calcium pathways are also involved. Long-term imaging of astrocyte populations revealed that all compartments reliably responded to stimulation over several months, but that the location of the response within processes may vary. These previously unknown characteristics of subcellular astrocyte calcium signals provide new insights into how astrocytes may encode local neuronal circuit activity. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  1. Real-time monitoring of the Trojan-horse effect of silver nanoparticles by using a genetically encoded fluorescent cell sensor.

    You, Fang; Tang, Wenqin; Yung, Lin-Yue Lanry

    2018-04-26

    Silver nanoparticles (AgNPs) are widely incorporated into commercial products due to their antimicrobial properties. As a consequence, concerns about the adverse effects induced by AgNPs to humans and the environment need to be carefully examined. The existing literature reveals that AgNPs exhibit certain toxic effects, but it remains to be proved whether AgNPs or the ionic silver (Ag+) released from AgNPs are the main toxic species. Here, a genetically encoded fluorescent protein sensor with high affinity to Ag+ was developed. The resulting sensor, MT2a-FRET, was found to be ratiometric, sensitive and selective toward only Ag+ but inert against AgNPs. This makes this sensor a potential useful tool for monitoring the real-time intracellular dissolutions of AgNPs. Our data supported that AgNPs display the "Trojan-horse" mechanism, where AgNPs are internalized by cells and undergo dissolution intracellularly. We further found that cells exhibited a detoxification ability to remove active Ag+ from cells in 48 hours.

  2. Combinatorial mutagenesis of the voltage-sensing domain enables the optical resolution of action potentials firing at 60 Hz by a genetically encoded fluorescent sensor of membrane potential.

    Piao, Hong Hua; Rajakumar, Dhanarajan; Kang, Bok Eum; Kim, Eun Ha; Baker, Bradley J

    2015-01-07

    ArcLight is a genetically encoded fluorescent voltage sensor using the voltage-sensing domain of the voltage-sensing phosphatase from Ciona intestinalis that gives a large but slow-responding optical signal in response to changes in membrane potential (Jin et al., 2012). Fluorescent voltage sensors using the voltage-sensing domain from other species give faster yet weaker optical signals (Baker et al., 2012; Han et al., 2013). Sequence alignment of voltage-sensing phosphatases from different species revealed conserved polar and charged residues at 7 aa intervals in the S1-S3 transmembrane segments of the voltage-sensing domain, suggesting potential coil-coil interactions. The contribution of these residues to the voltage-induced optical signal was tested using a cassette mutagenesis screen by flanking each transmembrane segment with unique restriction sites to allow for the testing of individual mutations in each transmembrane segment, as well as combinations in all four transmembrane segments. Addition of a counter charge in S2 improved the kinetics of the optical response. A double mutation in the S4 domain dramatically reduced the slow component of the optical signal seen in ArcLight. Combining that double S4 mutant with the mutation in the S2 domain yielded a probe with kinetics voltage-sensing domain could potentially lead to fluorescent sensors capable of optically resolving neuronal inhibition and subthreshold synaptic activity. Copyright © 2015 the authors 0270-6474/15/350372-15$15.00/0.

  3. Calcium supplements

    ... this page: //medlineplus.gov/ency/article/007477.htm Calcium supplements To use the sharing features on this page, please enable JavaScript. WHO SHOULD TAKE CALCIUM SUPPLEMENTS? Calcium is an important mineral for the ...

  4. A genetically-encoded YFP sensor with enhanced chloride sensitivity, photostability and reduced ph interference demonstrates augmented transmembrane chloride movement by gerbil prestin (SLC26a5.

    Sheng Zhong

    Full Text Available Chloride is the major anion in cells, with many diseases arising from disordered Cl- regulation. For the non-invasive investigation of Cl- flux, YFP-H148Q and its derivatives chameleon and Cl-Sensor previously were introduced as genetically encoded chloride indicators. Neither the Cl- sensitivity nor the pH-susceptibility of these modifications to YFP is optimal for precise measurements of Cl- under physiological conditions. Furthermore, the relatively poor photostability of YFP derivatives hinders their application for dynamic and quantitative Cl- measurements. Dynamic and accurate measurement of physiological concentrations of chloride would significantly affect our ability to study effects of chloride on cellular events.In this study, we developed a series of YFP derivatives to remove pH interference, increase photostability and enhance chloride sensitivity. The final product, EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP, has a chloride Kd of 14 mM and pKa of 5.9. The bleach time constant of 175 seconds is over 15-fold greater than wild-type EYFP. We have used the sensor fused to the transmembrane protein prestin (gerbil prestin, SLC26a5, and shown for the first time physiological (mM chloride flux in HEK cells expressing this protein. This modified fluorescent protein will facilitate investigations of dynamics of chloride ions and their mediation of cell function.Modifications to YFP (EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP results in a photostable fluorescent protein that allows measurement of physiological changes in chloride concentration while remaining minimally affected by changes in pH.

  5. A genetically-encoded YFP sensor with enhanced chloride sensitivity, photostability and reduced ph interference demonstrates augmented transmembrane chloride movement by gerbil prestin (SLC26a5).

    Zhong, Sheng; Navaratnam, Dhasakumar; Santos-Sacchi, Joseph

    2014-01-01

    Chloride is the major anion in cells, with many diseases arising from disordered Cl- regulation. For the non-invasive investigation of Cl- flux, YFP-H148Q and its derivatives chameleon and Cl-Sensor previously were introduced as genetically encoded chloride indicators. Neither the Cl- sensitivity nor the pH-susceptibility of these modifications to YFP is optimal for precise measurements of Cl- under physiological conditions. Furthermore, the relatively poor photostability of YFP derivatives hinders their application for dynamic and quantitative Cl- measurements. Dynamic and accurate measurement of physiological concentrations of chloride would significantly affect our ability to study effects of chloride on cellular events. In this study, we developed a series of YFP derivatives to remove pH interference, increase photostability and enhance chloride sensitivity. The final product, EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP), has a chloride Kd of 14 mM and pKa of 5.9. The bleach time constant of 175 seconds is over 15-fold greater than wild-type EYFP. We have used the sensor fused to the transmembrane protein prestin (gerbil prestin, SLC26a5), and shown for the first time physiological (mM) chloride flux in HEK cells expressing this protein. This modified fluorescent protein will facilitate investigations of dynamics of chloride ions and their mediation of cell function. Modifications to YFP (EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP) results in a photostable fluorescent protein that allows measurement of physiological changes in chloride concentration while remaining minimally affected by changes in pH.

  6. Biosynthesis of the 22nd Genetically Encoded Amino Acid Pyrrolysine: Structure and Reaction Mechanism of PylC at 1.5Å Resolution

    Quitterer, Felix; List, Anja; Beck, Philipp; Bacher, Adelbert; Groll, Michael

    2012-01-01

    The second step in the biosynthesis of the 22nd genetically encoded amino acid pyrrolysine (Pyl) is catalyzed by PylC that forms the pseudopeptide l-lysine-Nε-3R-methyl-d-ornithine. Here, we present six crystal structures of the monomeric active ligase in complex with substrates, reaction intermediates, and products including ATP, the non-hydrolyzable ATP analogue 5′-adenylyl-β-γ-imidodiphosphate, ADP, d-ornithine (d-Orn), l-lysine (Lys), phosphorylated d-Orn, l-lysine-Nε-d-ornithine, inorganic phosphate, carbonate, and Mg2 +. The overall structure of PylC reveals similarities to the superfamily of ATP-grasp enzymes; however, there exist unique structural and functional features for a topological control of successive substrate entry and product release. Furthermore, the presented high-resolution structures provide detailed insights into the reaction mechanism of isopeptide bond formation starting with phosphorylation of d-Orn by transfer of a phosphate moiety from activated ATP. The binding of Lys to the enzyme complex is then followed by an SN2 reaction resulting in l-lysine-Nε-d-ornithine and inorganic phosphate. Surprisingly, PylC harbors two adenine nucleotides bound at the active site, what has not been observed in any ATP-grasp protein analyzed to date. Whereas one ATP molecule is involved in catalysis, the second adenine nucleotide functions as a selective anchor for the C- and N-terminus of the Lys substrate and is responsible for protein stability as shown by mutagenesis. © 2012 Elsevier Ltd.

  7. Chimeric Feline Coronaviruses That Encode Type II Spike Protein on Type I Genetic Background Display Accelerated Viral Growth and Altered Receptor Usage▿

    Tekes, Gergely; Hofmann-Lehmann, Regina; Bank-Wolf, Barbara; Maier, Reinhard; Thiel, Heinz-Jürgen; Thiel, Volker

    2010-01-01

    Persistent infection of domestic cats with feline coronaviruses (FCoVs) can lead to a highly lethal, immunopathological disease termed feline infectious peritonitis (FIP). Interestingly, there are two serotypes, type I and type II FCoVs, that can cause both persistent infection and FIP, even though their main determinant of host cell tropism, the spike (S) protein, is of different phylogeny and displays limited sequence identity. In cell culture, however, there are apparent differences. Type II FCoVs can be propagated to high titers by employing feline aminopeptidase N (fAPN) as a cellular receptor, whereas the propagation of type I FCoVs is usually difficult, and the involvement of fAPN as a receptor is controversial. In this study we have analyzed the phenotypes of recombinant FCoVs that are based on the genetic background of type I FCoV strain Black but encode the type II FCoV strain 79-1146 S protein. Our data demonstrate that recombinant FCoVs expressing a type II FCoV S protein acquire the ability to efficiently use fAPN for host cell entry and corroborate the notion that type I FCoVs use another main host cell receptor. We also observed that recombinant FCoVs display a large-plaque phenotype and, unexpectedly, accelerated growth kinetics indistinguishable from that of type II FCoV strain 79-1146. Thus, the main phenotypic differences for type I and type II FCoVs in cell culture, namely, the growth kinetics and the efficient usage of fAPN as a cellular receptor, can be attributed solely to the FCoV S protein. PMID:19906918

  8. Biosynthesis of the 22nd Genetically Encoded Amino Acid Pyrrolysine: Structure and Reaction Mechanism of PylC at 1.5Å Resolution

    Quitterer, Felix

    2012-12-01

    The second step in the biosynthesis of the 22nd genetically encoded amino acid pyrrolysine (Pyl) is catalyzed by PylC that forms the pseudopeptide l-lysine-Nε-3R-methyl-d-ornithine. Here, we present six crystal structures of the monomeric active ligase in complex with substrates, reaction intermediates, and products including ATP, the non-hydrolyzable ATP analogue 5′-adenylyl-β-γ-imidodiphosphate, ADP, d-ornithine (d-Orn), l-lysine (Lys), phosphorylated d-Orn, l-lysine-Nε-d-ornithine, inorganic phosphate, carbonate, and Mg2 +. The overall structure of PylC reveals similarities to the superfamily of ATP-grasp enzymes; however, there exist unique structural and functional features for a topological control of successive substrate entry and product release. Furthermore, the presented high-resolution structures provide detailed insights into the reaction mechanism of isopeptide bond formation starting with phosphorylation of d-Orn by transfer of a phosphate moiety from activated ATP. The binding of Lys to the enzyme complex is then followed by an SN2 reaction resulting in l-lysine-Nε-d-ornithine and inorganic phosphate. Surprisingly, PylC harbors two adenine nucleotides bound at the active site, what has not been observed in any ATP-grasp protein analyzed to date. Whereas one ATP molecule is involved in catalysis, the second adenine nucleotide functions as a selective anchor for the C- and N-terminus of the Lys substrate and is responsible for protein stability as shown by mutagenesis. © 2012 Elsevier Ltd.

  9. Genetic diversity of EBV-encoded LMP1 in the Swiss HIV Cohort Study and implication for NF-Κb activation.

    Emilie Zuercher

    Full Text Available Epstein-Barr virus (EBV is associated with several types of cancers including Hodgkin's lymphoma (HL and nasopharyngeal carcinoma (NPC. EBV-encoded latent membrane protein 1 (LMP1, a multifunctional oncoprotein, is a powerful activator of the transcription factor NF-κB, a property that is essential for EBV-transformed lymphoblastoid cell survival. Previous studies reported LMP1 sequence variations and induction of higher NF-κB activation levels compared to the prototype B95-8 LMP1 by some variants. Here we used biopsies of EBV-associated cancers and blood of individuals included in the Swiss HIV Cohort Study (SHCS to analyze LMP1 genetic diversity and impact of sequence variations on LMP1-mediated NF-κB activation potential. We found that a number of variants mediate higher NF-κB activation levels when compared to B95-8 LMP1 and mapped three single polymorphisms responsible for this phenotype: F106Y, I124V and F144I. F106Y was present in all LMP1 isolated in this study and its effect was variant dependent, suggesting that it was modulated by other polymorphisms. The two polymorphisms I124V and F144I were present in distinct phylogenetic groups and were linked with other specific polymorphisms nearby, I152L and D150A/L151I, respectively. The two sets of polymorphisms, I124V/I152L and F144I/D150A/L151I, which were markers of increased NF-κB activation in vitro, were not associated with EBV-associated HL in the SHCS. Taken together these results highlighted the importance of single polymorphisms for the modulation of LMP1 signaling activity and demonstrated that several groups of LMP1 variants, through distinct mutational paths, mediated enhanced NF-κB activation levels compared to B95-8 LMP1.

  10. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    Sergeant, C. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France)]. E-mail: sergeant@cenbg.in2p3.fr; Vesvres, M.H. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France); Deves, G. [CNRS-Universite de Bordeaux I, UMR 5084, Chimie Nucleaire Analytique et Bio environnementale, Le Haut Vigneau, BP120, 33175 Bordeaux-Gradignan (France); Guillou, F. [INRA-CNRS-Universite de Tours-Haras nationaux, UMR 6175, Physiologie de la Reproduction et des Comportements, 37380 Nouzilly (France)

    2005-04-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter.

  11. Calcium, potassium, iron, copper and zinc concentrations in the white and gray matter of the cerebellum and corpus callosum in brain of four genetic mouse strains

    Sergeant, C.; Vesvres, M.H.; Deves, G.; Guillou, F.

    2005-01-01

    In the central nervous system, metallic cations are involved in oligodendrocyte maturation and myelinogenesis. Moreover, the metallic cations have been associated with pathogenesis, particularly multiple sclerosis and malignant gliomas. The brain is vulnerable to either a deficit or an excess of available trace elements. Relationship between trace metals and myelinogenesis is important in understanding a severe human pathology : the multiple sclerosis, which remains without efficient treatment. One approach to understand this disease has used mutant or transgenic mice presenting myelin deficiency or excess. But to date, the concentration of trace metals and mineral elements in white and gray matter areas in wild type brain is unknown. The aim of this study is to establish the reference concentrations of trace metals (iron, copper and zinc) and minerals (potassium and calcium) in the white and gray matter of the mouse cerebellum and corpus callosum. The brains of four different genetic mouse strains (C57Black6/SJL, C57Black6/D2, SJL and C3H) were analyzed. The freeze-dried samples were prepared to allow PIXE (Proton-induced X-ray emission) and RBS (Rutherford backscattering spectrometry) analyses with the nuclear microprobe in Bordeaux. The results obtained give the first reference values. Furthermore, one species out of the fours testes exhibited differences in calcium, iron and zinc concentrations in the white matter

  12. Voltage-Gated Calcium Channels

    Zamponi, Gerald Werner

    Voltage Gated Calcium Channels is the first comprehensive book in the calcium channel field, encompassing over thirty years of progress towards our understanding of calcium channel structure, function, regulation, physiology, pharmacology, and genetics. This book balances contributions from many of the leading authorities in the calcium channel field with fresh perspectives from risings stars in the area, taking into account the most recent literature and concepts. This is the only all-encompassing calcium channel book currently available, and is an essential resource for academic researchers at all levels in the areas neuroscience, biophysics, and cardiovascular sciences, as well as to researchers in the drug discovery area.

  13. Calcium absorption

    Carlmark, B.; Reizenstein, P.; Dudley, R.A.

    1976-01-01

    The methods most commonly used to measure the absorption and retention of orally administered calcium are reviewed. Nearly all make use of calcium radioisotopes. The magnitude of calcium absorption and retention depends upon the chemical form and amount of calcium administered, and the clinical and nutritional status of the subject; these influences are briefly surveyed. (author)

  14. Calcium - ionized

    ... diuretics Thrombocytosis (high platelet count) Tumors Vitamin A excess Vitamin D excess Lower-than-normal levels may be due to: Hypoparathyroidism Malabsorption Osteomalacia Pancreatitis Renal failure Rickets Vitamin D deficiency Alternative Names Free calcium; Ionized calcium ...

  15. Calcium Carbonate

    ... Calcium is needed by the body for healthy bones, muscles, nervous system, and heart. Calcium carbonate also ... to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in ...

  16. The Association between Genetic Variations of CHI3L1, Levels of the Encoded Glycoprotein YKL-40 and the Lipid Profile in a Danish Population

    Thomsen, Stine Brinkløv; Rathcke, Camilla Noelle; Skaaby, Tea

    2012-01-01

    The inflammatory biomarker YKL-40 seems to play a role in atherosclerosis and is elevated in patients with obesity, cardiovascular disease and type 2 diabetes. Single nucleotide polymorphisms (SNPs) of the YKL-40 encoding gene, CHI3L1, are associated with inter-individual YKL-40 levels. One study...... of the differentiated lipid profile in a Danish general population....

  17. Simultaneous mapping of membrane voltage and calcium in zebrafish heart in vivo reveals chamber-specific developmental transitions in ionic currents

    Jennifer H Hou

    2014-09-01

    Full Text Available The cardiac action potential (AP and the consequent cytosolic Ca2+ transient are key indicators of cardiac function. Natural developmental processes, as well as many drugs and pathologies change the waveform, propagation, or variability (between cells or over time of these parameters. Here we apply a genetically encoded dual-function calcium and voltage reporter (CaViar to study the development of the zebrafish heart in vivo between 1.5 and 4 days post fertilization (dpf. We developed a high-sensitivity spinning disk confocal microscope and associated software for simultaneous three-dimensional optical mapping of voltage and calcium. We produced a transgenic zebrafish line expressing CaViar under control of the heart-specific cmlc2 promoter, and applied ion channel blockers at a series of developmental stages to map the maturation of the action potential in vivo. Early in development, the AP initiated via a calcium current through L-type calcium channels. Between 90 – 102 hours post fertilization (hpf, the ventricular AP switched to a sodium-driven upswing, while the atrial AP remained calcium driven. In the adult zebrafish heart, a sodium current drives the AP in both the atrium and ventricle. Simultaneous voltage and calcium imaging with genetically encoded reporters provides a new approach for monitoring cardiac development, and the effects of drugs on cardiac function.

  18. In vivo calcium imaging from dentate granule cells with wide-field fluorescence microscopy.

    Yuichiro Hayashi

    Full Text Available A combination of genetically-encoded calcium indicators and micro-optics has enabled monitoring of large-scale dynamics of neuronal activity from behaving animals. In these studies, wide-field microscopy is often used to visualize neural activity. However, this method lacks optical sectioning capability, and therefore its axial resolution is generally poor. At present, it is unclear whether wide-field microscopy can visualize activity of densely packed small neurons at cellular resolution. To examine the applicability of wide-field microscopy for small-sized neurons, we recorded calcium activity of dentate granule cells having a small soma diameter of approximately 10 micrometers. Using a combination of high numerical aperture (0.8 objective lens and independent component analysis-based image segmentation technique, activity of putative single granule cell activity was separated from wide-field calcium imaging data. The result encourages wider application of wide-field microscopy in in vivo neurophysiology.

  19. Genetic analysis of the pelA-pelE cluster encoding the acidic and basic pectate lyases in Erwinia chrysanthemi EC16.

    Barras, F; Chatterjee, A K

    1987-10-01

    In Erwinia chrysanthemi (EC16) the clustered pelA and pelE genes encode an acidic (pI 4.2) and a basic (pI 10.0) pectate lyase (Pel), respectively. The pelA gene has been isolated on a 1.2 kb restriction fragment and the direction of transcription determined. DNA hybridization analysis showed that the pelE sequence shares DNA homology with pelA but not with pelB or pelC, two genes encoding other Pel species in EC16. Since Pel A and Pel E enzymes showed little similarity in terms of catalytic properties, it is proposed that pelA and pelE are duplicates which have highly diverged.

  20. Calcium waves.

    Jaffe, Lionel F

    2008-04-12

    Waves through living systems are best characterized by their speeds at 20 degrees C. These speeds vary from those of calcium action potentials to those of ultraslow ones which move at 1-10 and/or 10-20 nm s(-1). All such waves are known or inferred to be calcium waves. The two classes of calcium waves which include ones with important morphogenetic effects are slow waves that move at 0.2-2 microm s(-1) and ultraslow ones. Both may be propagated by cycles in which the entry of calcium through the plasma membrane induces subsurface contraction. This contraction opens nearby stretch-sensitive calcium channels. Calcium entry through these channels propagates the calcium wave. Many slow waves are seen as waves of indentation. Some are considered to act via cellular peristalsis; for example, those which seem to drive the germ plasm to the vegetal pole of the Xenopus egg. Other good examples of morphogenetic slow waves are ones through fertilizing maize eggs, through developing barnacle eggs and through axolotl embryos during neural induction. Good examples of ultraslow morphogenetic waves are ones during inversion in developing Volvox embryos and across developing Drosophila eye discs. Morphogenetic waves may be best pursued by imaging their calcium with aequorins.

  1. Filamin and phospholipase C-ε are required for calcium signaling in the Caenorhabditis elegans spermatheca.

    Ismar Kovacevic

    2013-05-01

    Full Text Available The Caenorhabditis elegans spermatheca is a myoepithelial tube that stores sperm and undergoes cycles of stretching and constriction as oocytes enter, are fertilized, and exit into the uterus. FLN-1/filamin, a stretch-sensitive structural and signaling scaffold, and PLC-1/phospholipase C-ε, an enzyme that generates the second messenger IP3, are required for embryos to exit normally after fertilization. Using GCaMP, a genetically encoded calcium indicator, we show that entry of an oocyte into the spermatheca initiates a distinctive series of IP3-dependent calcium oscillations that propagate across the tissue via gap junctions and lead to constriction of the spermatheca. PLC-1 is required for the calcium release mechanism triggered by oocyte entry, and FLN-1 is required for timely initiation of the calcium oscillations. INX-12, a gap junction subunit, coordinates propagation of the calcium transients across the spermatheca. Gain-of-function mutations in ITR-1/IP3R, an IP3-dependent calcium channel, and loss-of-function mutations in LFE-2, a negative regulator of IP3 signaling, increase calcium release and suppress the exit defect in filamin-deficient animals. We further demonstrate that a regulatory cassette consisting of MEL-11/myosin phosphatase and NMY-1/non-muscle myosin is required for coordinated contraction of the spermatheca. In summary, this study answers long-standing questions concerning calcium signaling dynamics in the C. elegans spermatheca and suggests FLN-1 is needed in response to oocyte entry to trigger calcium release and coordinated contraction of the spermathecal tissue.

  2. Division of Giardia isolates from humans into two genetically distinct assemblages by electrophoretic analysis of enzymes encoded at 27 loci and comparison with Giardia muris.

    Mayrhofer, G; Andrews, R H; Ey, P L; Chilton, N B

    1995-07-01

    Giardia that infect humans are known to be heterogeneous but they are assigned currently to a single species, Giardia intestinalis (syn. G. lamblia). The genetic differences that exist within G. intestinalis have not yet been assessed quantitatively and neither have they been compared in magnitude with those that exist between G. intestinalis and species that are morphologically similar (G. duodenalis) or morphologically distinct (e.g. G. muris). In this study, 60 Australian isolates of G. intestinalis were analysed electrophoretically at 27 enzyme loci and compared with G. muris and a feline isolate of G. duodenalis. Isolates of G. intestinalis were distinct genetically from both G. muris (approximately 80% fixed allelic differences) and the feline G. duodenalis isolate (approximately 75% fixed allelic differences). The G. intestinalis isolates were extremely heterogeneous but they fell into 2 major genetic assemblages, separated by fixed allelic differences at approximately 60% of loci examined. The magnitude of the genetic differences between the G. intestinalis assemblages approached the level that distinguished the G. duodenalis isolate from the morphologically distinct G. muris. This raises important questions about the evolutionary relationships of the assemblages with Homo sapiens, the possibility of ancient or contemporary transmission from animal hosts to humans and the biogeographical origins of the two clusters.

  3. Development and implementation of a high-throughput compound screening assay for targeting disrupted ER calcium homeostasis in Alzheimer's disease.

    Kamran Honarnejad

    Full Text Available Disrupted intracellular calcium homeostasis is believed to occur early in the cascade of events leading to Alzheimer's disease (AD pathology. Particularly familial AD mutations linked to Presenilins result in exaggerated agonist-evoked calcium release from endoplasmic reticulum (ER. Here we report the development of a fully automated high-throughput calcium imaging assay utilizing a genetically-encoded FRET-based calcium indicator at single cell resolution for compound screening. The established high-throughput screening assay offers several advantages over conventional high-throughput calcium imaging technologies. We employed this assay for drug discovery in AD by screening compound libraries consisting of over 20,000 small molecules followed by structure-activity-relationship analysis. This led to the identification of Bepridil, a calcium channel antagonist drug in addition to four further lead structures capable of normalizing the potentiated FAD-PS1-induced calcium release from ER. Interestingly, it has recently been reported that Bepridil can reduce Aβ production by lowering BACE1 activity. Indeed, we also detected lowered Aβ, increased sAPPα and decreased sAPPβ fragment levels upon Bepridil treatment. The latter findings suggest that Bepridil may provide a multifactorial therapeutic modality for AD by simultaneously addressing multiple aspects of the disease.

  4. Enhanced proteolysis of thiopurine S-methyltransferase (TPMT) encoded by mutant alleles in humans (TPMT∗3A, TPMT∗2): Mechanisms for the genetic polymorphism of TPMT activity

    Tai, Hung-Liang; Krynetski, Eugene Y.; Schuetz, Erin G.; Yanishevski, Yuri; Evans, William E.

    1997-01-01

    TPMT is a cytosolic enzyme that catalyzes the S-methylation of aromatic and heterocyclic sulfhydryl compounds, including medications such as mercaptopurine and thioguanine. TPMT activity exhibits autosomal codominant genetic polymorphism, and patients inheriting TPMT deficiency are at high risk of potentially fatal hematopoietic toxicity. The most prevalent mutant alleles associated with TPMT deficiency in humans have been cloned and characterized (TPMT∗2 and TPMT∗3A), but the mechanisms for ...

  5. Calcium Electroporation

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha

    2015-01-01

    BACKGROUND: Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill...... efficacy-and normal cell sensitivity. METHODS: Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780......), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). RESULTS: The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (p

  6. Molecular genetic analysis of the calcium sensing receptor gene in patients clinically suspected to have familial hypocalciuric hypercalcemia: phenotypic variation and mutation spectrum in a Danish population

    Nissen, Peter H; Christensen, Signe E; Heickendorff, Lene

    2007-01-01

    CONTEXT: The autosomal dominantly inherited condition familial hypocalciuric hypercalcemia (FHH) is characterized by elevated plasma calcium levels, relative or absolute hypocalciuria, and normal to moderately elevated plasma PTH. The condition is difficult to distinguish clinically from primary...... hyperparathyroidism and is caused by inactivating mutations in the calcium sensing receptor (CASR) gene. OBJECTIVE: We sought to define the mutation spectrum of the CASR gene in a Danish FHH population and to establish genotype-phenotype relationships regarding the different mutations. DESIGN AND PARTICIPANTS...

  7. Serum Brain-Derived Neurotrophic Factor is Related to Platelet Reactivity but not to Genetic Polymorphisms within BDNF Encoding Gene in Patients with Type 2 Diabetes.

    Eyileten, Ceren; Zaremba, Małgorzata; Janicki, Piotr K; Rosiak, Marek; Cudna, Agnieszka; Kapłon-Cieślicka, Agnieszka; Opolski, Grzegorz; Filipiak, Krzysztof J; Kosior, Dariusz A; Mirowska-Guzel, Dagmara; Postula, Marek

    2016-01-07

    The aim of this study was to investigate the association between serum concentrations of the brain-derived neurotrophic factor (BDNF), platelet reactivity and inflammatory markers, as well as its association with BDNF encoding gene variants in type 2 diabetic patients (T2DM) during acetylsalicylic acid (ASA) therapy. This retrospective, open-label study enrolled 91 patients. Serum BDNF, genotype variants, hematological, biochemical, and inflammatory markers were measured. Blood samples were taken in the morning 2-3 h after the last ASA dose. The BDNF genotypes for selected variants were analyzed by use of the iPLEX Sequenom assay. In multivariate linear regression analysis, CADP-CT >74 sec (pBDNF. In multivariate logistic regression analysis, CADP-CT >74 sec (p=0.02) and IL-6 concentration (p=0.03) were risk factors for serum BDNF above the median. Non-significant differences were observed between intronic SNP rs925946, missense SNP rs6265, and intronic SNP rs4923463 allelic groups and BDNF concentrations in the investigated cohort. Chronic inflammatory condition and enhanced immune system are associated with the production of BDNF, which may be why the serum BDNF level in T2DM patients with high platelet reactivity was higher compared to subjects with normal platelet reactivity in this study.

  8. A genetic association study of the FXYD domain containing ion transport regulator 6 (FXYD6) gene, encoding phosphohippolin, in susceptibility to schizophrenia in a Japanese population.

    Ito, Yoshihito; Nakamura, Yukako; Takahashi, Nagahide; Saito, Shinichi; Aleksic, Branko; Iwata, Nakao; Inada, Toshiya; Ozaki, Norio

    2008-06-13

    The FXYD domain containing ion transport regulator 6 (FXYD6) gene is located within a region of chromosome 11 (11q23.3) that has been shown by a number of genome scans to be one of the most well-established linkages to schizophrenia. FXYD6 encodes the protein phosphohippolin, which is primarily expressed in the brain. Phosphohippolin modulates the kinetic activity of Na,K-ATPase and has long-term physiological importance in maintaining cation homeostasis. A recent study reported that FXYD6 was associated with schizophrenia in the United Kingdom samples. Applying the gene-based association concept, we carried out an association study regarding FXYD6 and schizophrenia in a Japanese population, with a sample consisting of 2026 subjects (906 schizophrenics and 1120 controls). After linkage disequilibrium analysis, 23 single nucleotide polymorphisms (SNPs) were genotyped using 5'-exonuclease allelic discrimination assay. We found a significant association of two SNPs (rs11216573; genotypic P value: 0.022 and rs555577; genotypic P value: 0.026, allelic P value: 0.011, uncorrected). Nominal P values did not survive correction for multiple testing (rs11216573; genotypic P value: 0.47 and rs555577; genotypic P value: 0.55, allelic P value: 0.24, after SNPSpD correction). No association was observed between schizophrenia patients and controls in allelic, genotypic and haplotypic analyses. Our findings suggest that FXYD6 is unlikely to be related to the development of schizophrenia in a Japanese population.

  9. Transgenic plants with increased calcium stores

    Wyatt, Sarah (Inventor); Tsou, Pei-Lan (Inventor); Robertson, Dominique (Inventor); Boss, Wendy (Inventor)

    2004-01-01

    The present invention provides transgenic plants over-expressing a transgene encoding a calcium-binding protein or peptide (CaBP). Preferably, the CaBP is a calcium storage protein and over-expression thereof does not have undue adverse effects on calcium homeostasis or biochemical pathways that are regulated by calcium. In preferred embodiments, the CaBP is calreticulin (CRT) or calsequestrin. In more preferred embodiments, the CaBP is the C-domain of CRT, a fragment of the C-domain, or multimers of the foregoing. In other preferred embodiments, the CaBP is localized to the endoplasmic reticulum by operatively associating the transgene encoding the CaBP with an endoplasmic reticulum localization peptide. Alternatively, the CaBP is targeted to any other sub-cellular compartment that permits the calcium to be stored in a form that is biologically available to the plant. Also provided are methods of producing plants with desirable phenotypic traits by transformation of the plant with a transgene encoding a CaBP. Such phenotypic traits include increased calcium storage, enhanced resistance to calcium-limiting conditions, enhanced growth and viability, increased disease and stress resistance, enhanced flower and fruit production, reduced senescence, and a decreased need for fertilizer production. Further provided are plants with enhanced nutritional value as human food or animal feed.

  10. Genetics

    Hubitschek, H.E.

    1975-01-01

    Progress is reported on the following research projects: genetic effects of high LET radiations; genetic regulation, alteration, and repair; chromosome replication and the division cycle of Escherichia coli; effects of radioisotope decay in the DNA of microorganisms; initiation and termination of DNA replication in Bacillus subtilis; mutagenesis in mouse myeloma cells; lethal and mutagenic effects of near-uv radiation; effect of 8-methoxypsoralen on photodynamic lethality and mutagenicity in Escherichia coli; DNA repair of the lethal effects of far-uv; and near uv irradiation of bacterial cells

  11. PLA2G6, encoding a phospholipase A2, is mutated in neurodegenerative disorders with high brain iron

    Morgan, Neil V; Westaway, Shawn K; Morton, Jenny E V; Gregory, Allison; Gissen, Paul; Sonek, Scott; Cangul, Hakan; Coryell, Jason; Canham, Natalie; Nardocci, Nardo; Zorzi, Giovanna; Pasha, Shanaz; Rodriguez, Diana; Desguerre, Isabelle; Mubaidin, Amar; Bertini, Enrico; Trembath, Richard C; Simonati, Alessandro; Schanen, Carolyn; Johnson, Colin A; Levinson, Barbara; Woods, C Geoffrey; Wilmot, Beth; Kramer, Patricia; Gitschier, Jane; Maher, Eamonn R; Hayflick, Susan J

    2007-01-01

    Neurodegenerative disorders with high brain iron include Parkinson disease, Alzheimer disease and several childhood genetic disorders categorized as neuroaxonal dystrophies. We mapped a locus for infantile neuroaxonal dystrophy (INAD) and neurodegeneration with brain iron accumulation (NBIA) to chromosome 22q12-q13 and identified mutations in PLA2G6, encoding a calcium-independent group VI phospholipase A2, in NBIA, INAD and the related Karak syndrome. This discovery implicates phospholipases in the pathogenesis of neurodegenerative disorders with iron dyshomeostasis. PMID:16783378

  12. Genetical and functional investigation of fliC genes encoding flagellar serotype H4 in wildtype strains of Escherichia coli and in a laboratory E. coli K-12 strain expressing flagellar antigen type H48

    Schaudinn Christoph

    2005-01-01

    Full Text Available Abstract Background Serotyping of O-(lipopolysaccharide and H-(flagellar antigens is a wideley used method for identification of pathogenic strains and clones of Escherichia coli. At present, 176 O- and 53 H-antigens are described for E. coli which occur in different combinations in the strains. The flagellar antigen H4 is widely present in E. coli strains of different O-serotypes and pathotypes and we have investigated the genetic relationship between H4 encoding fliC genes by PCR, nucleotide sequencing and expression studies. Results The complete nucleotide sequence of fliC genes present in E. coli reference strains U9-41 (O2:K1:H4 and P12b (O15:H17 was determined and both were found 99.3% (1043 of 1050 nucleotides identical in their coding sequence. A PCR/RFLP protocol was developed for typing of fliC-H4 strains and 88 E. coli strains reacting with H4 antiserum were investigated. Nucleotide sequencing of complete fliC genes of six E. coli strains which were selected based on serum agglutination titers, fliC-PCR genotyping and reference data revealed 96.6 to 100% identity on the amino acid level. The functional expression of flagellin encoded by fliC-H4 from strain U9-41 and from our strain P12b which is an H4 expressing variant type was investigated in the E. coli K-12 strain JM109 which encodes flagellar type H48. The fliC recombinant plasmid carrying JM109 strains reacted with both H4 and H48 specific antisera whereas JM109 reacted only with the H48 antiserum. By immunoelectron microscopy, we could show that the flagella made by the fliC-H4 recombinant plasmid carrying strain are constituted of H48 and H4 flagellins which are co-assembled into functional flagella. Conclusion The flagellar serotype H4 is encoded by closely related fliC genes present in serologically different types of E. coli strainswhich were isolated at different time periods and geographical locations. Our expression studies show for the first time, that flagellins of

  13. Genetics

    Christensen, Kaare; McGue, Matt

    2016-01-01

    The sequenced genomes of individuals aged ≥80 years, who were highly educated, self-referred volunteers and with no self-reported chronic diseases were compared to young controls. In these data, healthy ageing is a distinct phenotype from exceptional longevity and genetic factors that protect...

  14. A Preliminary Study of DBH (Encoding Dopamine Beta-Hydroxylase) Genetic Variation and Neural Correlates of Emotional and Motivational Processing in Individuals With and Without Pathological Gambling.

    Yang, Bao-Zhu; Balodis, Iris M; Lacadie, Cheryl M; Xu, Jiansong; Potenza, Marc N

    2016-06-01

    Background and aims Corticostriatal-limbic neurocircuitry, emotional and motivational processing, dopaminergic and noradrenergic systems and genetic factors have all been implicated in pathological gambling (PG). However, allelic variants of genes influencing dopaminergic and noradrenergic neurotransmitters have not been investigated with respect to the neural correlates of emotional and motivational states in PG. Dopamine beta-hydroxylase (DBH) converts dopamine to norepinephrine; the T allele of a functional single-nucleotide polymorphism rs1611115 (C-1021T) in the DBH gene is associated with less DBH activity and has been linked to emotional processes and addiction. Here, we investigate the influence of rs1611115 on the neural correlates of emotional and motivational processing in PG and healthy comparison (HC) participants. Methods While undergoing functional magnetic resonance imaging, 18 PG and 25 HC participants, all European Americans, viewed gambling-, sad-, and cocaine-related videotapes. Analyses focused on brain activation differences related to DBH genotype (CC/T-carrier [i.e., CT and TT]) and condition (sad/gambling/cocaine). Results CC participants demonstrated greater recruitment of corticostriatal-limbic regions, relative to T-carriers. DBH variants were also associated with altered corticostriatal-limbic activations across the different videotape conditions, and this association appeared to be driven by greater activation in CC participants relative to T-carriers during the sad condition. CC relative to T-carrier subjects also reported greater subjective sadness to the sad videotapes. Conclusions Individual differences in genetic composition linked to aminergic function contribute significantly to emotional regulation across diagnostic groups and warrant further investigation in PG.

  15. ALG-2, a multifunctional calcium binding protein?

    Tarabykina, Svetlana; Mollerup, Jens; Winding Gojkovic, P.

    2004-01-01

    ALG-2 was originally discovered as a pro-apoptotic protein in a genetic screen. Due to its ability to bind calcium with high affinity it was postulated to provide a link between the known effect of calcium in programmed cell death and the molecular death execution machinery. This review article...

  16. Local adaptations in bryophytes revisited: the genetic structure of the calcium-tolerant peatmoss Sphagnum warnstorfii along geographic and pH gradients

    Mikulášková, E.; Hájek, Michal; Veleba, A.; Johnson, M. G.; Hájek, Tomáš; Shaw, J. A.

    2015-01-01

    Roč. 5, č. 1 (2015), s. 229-242 ISSN 2045-7758 R&D Projects: GA ČR GAP505/10/0638 Institutional support: RVO:67985939 Keywords : Calcium tolerance * hybridization * population structure Subject RIV: EH - Ecology, Behaviour Impact factor: 2.537, year: 2015

  17. Calcium-sensing beyond neurotransmitters

    Gustavsson, Natalia; Han, Weiping

    2009-01-01

    Neurotransmitters, neuropeptides and hormones are released through the regulated exocytosis of SVs (synaptic vesicles) and LDCVs (large dense-core vesicles), a process that is controlled by calcium. Synaptotagmins are a family of type 1 membrane proteins that share a common domain structure. Most....... Also, we discuss potential roles of synaptotagmins in non-traditional endocrine systems....... synaptotagmins are located in brain and endocrine cells, and some of these synaptotagmins bind to phospholipids and calcium at levels that trigger regulated exocytosis of SVs and LDCVs. This led to the proposed synaptotagmin-calcium-sensor paradigm, that is, members of the synaptotagmin family function...... as calcium sensors for the regulated exocytosis of neurotransmitters, neuropeptides and hormones. Here, we provide an overview of the synaptotagmin family, and review the recent mouse genetic studies aimed at understanding the functions of synaptotagmins in neurotransmission and endocrine-hormone secretion...

  18. Get Enough Calcium

    ... Calcium Print This Topic En español Get Enough Calcium Browse Sections The Basics Overview Foods and Vitamins ... women, don't get enough calcium. How much calcium do I need every day? Women: If you ...

  19. Calcium - urine

    ... Female urinary tract Male urinary tract Calcium urine test References Bringhurst FR, Demay MB, Kronenberg HM. Hormones and disorders of mineral metabolism. In: Melmed S, Polonsky KS, Larsen PR, Kronenberg HM, eds. Williams Textbook of Endocrinology . 13th ed. Philadelphia, PA: Elsevier; ...

  20. Heat transfer analysis of unsteady graphene oxide nanofluid flow using a fuzzy identifier evolved by genetically encoded mutable smart bee algorithm

    Mohammadreza Azimi

    2015-03-01

    Full Text Available In the current research, the unsteady two dimensional Graphene Oxide water based nanofluid heat transfer between two moving parallel plates is analyzed using an intelligent black-box identifier. The developed intelligent tool is known as evolvable evolutionary fuzzy inference system (EE-FIS which is based on the integration of low-level fuzzy programming and hyper-level evolutionary computing concepts. Here, the authors propose the use of a modified evolutionary algorithm (EA which is called hybrid genetic mutable smart bee algorithm (HGMSBA. The proposed HGMSBA is used to evolve both antecedent and consequent parts of fuzzy rule base. Besides, it tries to prune the rule base of fuzzy inference system (FIS to decrease its computational complexity and increase its interpretability. By considering the prediction error of the fuzzy identifier as the objective function of HGMSBA, an automatic soft interpolation machine is developed which can intuitively increase the robustness and accuracy of the final model. Here, HGMSBA-FIS is used to provide a nonlinear map between inputs, i.e. nanoparticles solid volume fraction (ϕ, Eckert number (Ec and a moving parameter which describes the movements of plates (S, and output, i.e. Nusselt number (Nu. Prior to proceeding with the modeling process, a comprehensive numerical comparative study is performed to investigate the potentials of the proposed model for nonlinear system identification. After demonstrating the efficacy of HGMSBA for training the FIS, the system is applied to the considered problem. Based on the obtained results, it can be inferred that the developed HGMSBA-FIS black-box identifier can be used as a very authentic tool with respect to accuracy and robustness. Besides, as the proposed black-box is not a physics-based identifier, it frees experts from the cumbersome mathematical formulations, and can be used for advanced real-time applications such as model-based control. The simulations

  1. Support for calcium channel gene defects in autism spectrum disorders

    Lu Ake Tzu-Hui

    2012-12-01

    Full Text Available Abstract Background Alternation of synaptic homeostasis is a biological process whose disruption might predispose children to autism spectrum disorders (ASD. Calcium channel genes (CCG contribute to modulating neuronal function and evidence implicating CCG in ASD has been accumulating. We conducted a targeted association analysis of CCG using existing genome-wide association study (GWAS data and imputation methods in a combined sample of parent/affected child trios from two ASD family collections to explore this hypothesis. Methods A total of 2,176 single-nucleotide polymorphisms (SNP (703 genotyped and 1,473 imputed covering the genes that encode the α1 subunit proteins of 10 calcium channels were tested for association with ASD in a combined sample of 2,781 parent/affected child trios from 543 multiplex Caucasian ASD families from the Autism Genetics Resource Exchange (AGRE and 1,651 multiplex and simplex Caucasian ASD families from the Autism Genome Project (AGP. SNP imputation using IMPUTE2 and a combined reference panel from the HapMap3 and the 1,000 Genomes Project increased coverage density of the CCG. Family-based association was tested using the FBAT software which controls for population stratification and accounts for the non-independence of siblings within multiplex families. The level of significance for association was set at 2.3E-05, providing a Bonferroni correction for this targeted 10-gene panel. Results Four SNPs in three CCGs were associated with ASD. One, rs10848653, is located in CACNA1C, a gene in which rare de novo mutations are responsible for Timothy syndrome, a Mendelian disorder that features ASD. Two others, rs198538 and rs198545, located in CACN1G, and a fourth, rs5750860, located in CACNA1I, are in CCGs that encode T-type calcium channels, genes with previous ASD associations. Conclusions These associations support a role for common CCG SNPs in ASD.

  2. Oxidized Low-density Lipoprotein (ox-LDL) Cholesterol Induces the Expression of miRNA-223 and L-type Calcium Channel Protein in Atrial Fibrillation

    He, Fengping; Xu, Xin; Yuan, Shuguo; Tan, Liangqiu; Gao, Lingjun; Ma, Shaochun; Zhang, Shebin; Ma, Zhanzhong; Jiang, Wei; Liu, Fenglian; Chen, Baofeng; Zhang, Beibei; Pang, Jungang; Huang, Xiuyan; Weng, Jiaqiang

    2016-08-01

    Atrial fibrillation (AF) is the most common sustained arrhythmia causing high morbidity and mortality. While changing of the cellular calcium homeostasis plays a critical role in AF, the L-type calcium channel α1c protein has suggested as an important regulator of reentrant spiral dynamics and is a major component of AF-related electrical remodeling. Our computational modeling predicted that miRNA-223 may regulate the CACNA1C gene which encodes the cardiac L-type calcium channel α1c subunit. We found that oxidized low-density lipoprotein (ox-LDL) cholesterol significantly up-regulates both the expression of miRNA-223 and L-type calcium channel protein. In contrast, knockdown of miRNA-223 reduced L-type calcium channel protein expression, while genetic knockdown of endogenous miRNA-223 dampened AF vulnerability. Transfection of miRNA-223 by adenovirus-mediated expression enhanced L-type calcium currents and promoted AF in mice while co-injection of a CACNA1C-specific miR-mimic counteracted the effect. Taken together, ox-LDL, as a known factor in AF-associated remodeling, positively regulates miRNA-223 transcription and L-type calcium channel protein expression. Our results implicate a new molecular mechanism for AF in which miRNA-223 can be used as an biomarker of AF rheumatic heart disease.

  3. Mammary-Specific Ablation of the Calcium-Sensing Receptor During Lactation Alters Maternal Calcium Metabolism, Milk Calcium Transport, and Neonatal Calcium Accrual

    Mamillapalli, Ramanaiah; VanHouten, Joshua; Dann, Pamela; Bikle, Daniel; Chang, Wenhan; Brown, Edward

    2013-01-01

    To meet the demands for milk calcium, the lactating mother adjusts systemic calcium and bone metabolism by increasing dietary calcium intake, increasing bone resorption, and reducing renal calcium excretion. As part of this adaptation, the lactating mammary gland secretes PTHrP into the maternal circulation to increase bone turnover and mobilize skeletal calcium stores. Previous data have suggested that, during lactation, the breast relies on the calcium-sensing receptor (CaSR) to coordinate PTHrP secretion and milk calcium transport with calcium availability. To test this idea genetically, we bred BLG-Cre mice with CaSR-floxed mice to ablate the CaSR specifically from mammary epithelial cells only at the onset of lactation (CaSR-cKO mice). Loss of the CaSR in the lactating mammary gland did not disrupt alveolar differentiation or milk production. However, it did increase the secretion of PTHrP into milk and decreased the transport of calcium from the circulation into milk. CaSR-cKO mice did not show accelerated bone resorption, but they did have a decrease in bone formation. Loss of the mammary gland CaSR resulted in hypercalcemia, decreased PTH secretion, and increased renal calcium excretion in lactating mothers. Finally, loss of the mammary gland CaSR resulted in decreased calcium accrual by suckling neonates, likely due to the combination of increased milk PTHrP and decreased milk calcium. These results demonstrate that the mammary gland CaSR coordinates maternal bone and calcium metabolism, calcium transport into milk, and neonatal calcium accrual during lactation. PMID:23782944

  4. Calcium paradox and calcium entry blockers

    Ruigrok, T.J.C.; Slade, A.M.; Nayler, W.G.; Meijler, F.L.

    1984-01-01

    Reperfusion of isolated hearts with calcium-containing solution after a short period of calcium-free perfusion results in irreversible cell damage (calcium paradox). This phenomenon is characterized by an excessive influx of calcium into the cells, the rapid onset of myocardial contracture,

  5. Function of endoplasmic reticulum calcium ATPase in innate immunity-mediated programmed cell death

    Zhu, Xiaohong; Caplan, Jeffrey; Mamillapalli, Padmavathi; Czymmek, Kirk; Dinesh-Kumar, Savithramma P

    2010-01-01

    Programmed cell death (PCD) initiated at the pathogen-infected sites during the plant innate immune response is thought to prevent the development of disease. Here, we describe the identification and characterization of an ER-localized type IIB Ca2+-ATPase (NbCA1) that function as a regulator of PCD. Silencing of NbCA1 accelerates viral immune receptor N- and fungal-immune receptor Cf9-mediated PCD, as well as non-host pathogen Pseudomonas syringae pv. tomato DC3000 and the general elicitor cryptogein-induced cell death. The accelerated PCD rescues loss-of-resistance phenotype of Rar1, HSP90-silenced plants, but not SGT1-silenced plants. Using a genetically encoded calcium sensor, we show that downregulation of NbCA1 results in the modulation of intracellular calcium signalling in response to cryptogein elicitor. We further show that NbCAM1 and NbrbohB function as downstream calcium decoders in N-immune receptor-mediated PCD. Our results indicate that ER-Ca2+-ATPase is a component of the calcium efflux pathway that controls PCD during an innate immune response. PMID:20075858

  6. Genetically encoded fluorescent coumarin amino acids

    Wang, Jiangyun; Xie, Jianming; Schultz, Peter G.

    2010-10-05

    The invention relates to orthogonal pairs of tRNAs and aminoacyl-tRNA synthetases that can incorporate the coumarin unnatural amino acid L-(7-hydroxycoumarin-4-yl) ethylglycine into proteins produced in eubacterial host cells such as E. coli. The invention provides, for example but not limited to, novel orthogonal synthetases, methods for identifying and making the novel synthetases, methods for producing proteins containing the unnatural amino acid L-(7-hydroxycoumarin-4-yl)ethylglycine and related translation systems.

  7. Genetically encoded fluorescent probe to visualize phosphatidylinositol

    Eisenreichová, Andrea; Humpolíčková, Jana; Bouřa, Evžen

    2017-01-01

    Roč. 284, Suppl 1 (2017), s. 364-365 ISSN 1742-464X. [FEBS Congress /42./ From Molecules to Cells and Back. 10.09.2017-14.09.2017, Jerusalem] R&D Projects: GA ČR GJ15-21030Y; GA MŠk LO1302 Institutional support: RVO:61388963 Keywords : phosphatidylinositol * fluorescent probe Subject RIV: CE - Biochemistry

  8. Meta-analysis of genome-wide association studies identifies six new Loci for serum calcium concentrations.

    Conall M O'Seaghdha

    Full Text Available Calcium is vital to the normal functioning of multiple organ systems and its serum concentration is tightly regulated. Apart from CASR, the genes associated with serum calcium are largely unknown. We conducted a genome-wide association meta-analysis of 39,400 individuals from 17 population-based cohorts and investigated the 14 most strongly associated loci in ≤ 21,679 additional individuals. Seven loci (six new regions in association with serum calcium were identified and replicated. Rs1570669 near CYP24A1 (P = 9.1E-12, rs10491003 upstream of GATA3 (P = 4.8E-09 and rs7481584 in CARS (P = 1.2E-10 implicate regions involved in Mendelian calcemic disorders: Rs1550532 in DGKD (P = 8.2E-11, also associated with bone density, and rs7336933 near DGKH/KIAA0564 (P = 9.1E-10 are near genes that encode distinct isoforms of diacylglycerol kinase. Rs780094 is in GCKR. We characterized the expression of these genes in gut, kidney, and bone, and demonstrate modulation of gene expression in bone in response to dietary calcium in mice. Our results shed new light on the genetics of calcium homeostasis.

  9. Peripheral serotonin regulates maternal calcium trafficking in mammary epithelial cells during lactation in mice.

    Jimena Laporta

    Full Text Available Lactation is characterized by massive transcellular flux of calcium, from the basolateral side of the mammary alveolar epithelium (blood into the ductal lumen (milk. Regulation of calcium transport during lactation is critical for maternal and neonatal health. The monoamine serotonin (5-HT is synthesized by the mammary gland and functions as a homeostatic regulation of lactation. Genetic ablation of tryptophan hydroxylase 1 (Tph1, which encodes the rate-limiting enzyme in non-neuronal serotonin synthesis, causes a deficiency in circulating serotonin. As a consequence maternal calcium concentrations decrease, mammary epithelial cell morphology is altered, and cell proliferation is decreased during lactation. Here we demonstrate that serotonin deficiency decreases the expression and disrupts the normal localization of calcium transporters located in the apical (PMCA2 and basolateral (CaSR, ORAI-1 membranes of the lactating mammary gland. In addition, serotonin deficiency decreases the mRNA expression of calcium transporters located in intracellular compartments (SERCA2, SPCA1 and 2. Mammary expression of serotonin receptor isoform 2b and its downstream pathways (PLCβ3, PKC and MAP-ERK1/2 are also decreased by serotonin deficiency, which might explain the numerous phenotypic alterations described above. In most cases, addition of exogenous 5-hydroxy-L-tryptophan to the Tph1 deficient mice rescued the phenotype. Our data supports the hypothesis that serotonin is necessary for proper mammary gland structure and function, to regulate blood and mammary epithelial cell transport of calcium during lactation. These findings can be applicable to the treatment of lactation-induced hypocalcemia in dairy cows and can have profound implications in humans, given the wide-spread use of selective serotonin reuptake inhibitors as antidepressants during pregnancy and lactation.

  10. A Genetically-Encoded YFP Sensor with Enhanced Chloride Sensitivity, Photostability and Reduced pH Interference Demonstrates Augmented Transmembrane Chloride Movement by Gerbil Prestin (SLC26a5)

    Zhong, Sheng; Navaratnam, Dhasakumar; Santos-Sacchi, Joseph

    2014-01-01

    Background Chloride is the major anion in cells, with many diseases arising from disordered Cl− regulation. For the non-invasive investigation of Cl− flux, YFP-H148Q and its derivatives chameleon and Cl-Sensor previously were introduced as genetically encoded chloride indicators. Neither the Cl− sensitivity nor the pH-susceptibility of these modifications to YFP is optimal for precise measurements of Cl− under physiological conditions. Furthermore, the relatively poor photostability of YFP derivatives hinders their application for dynamic and quantitative Cl− measurements. Dynamic and accurate measurement of physiological concentrations of chloride would significantly affect our ability to study effects of chloride on cellular events. Methodology/Principal Findings In this study, we developed a series of YFP derivatives to remove pH interference, increase photostability and enhance chloride sensitivity. The final product, EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP), has a chloride Kd of 14 mM and pKa of 5.9. The bleach time constant of 175 seconds is over 15-fold greater than wild-type EYFP. We have used the sensor fused to the transmembrane protein prestin (gerbil prestin, SLC26a5), and shown for the first time physiological (mM) chloride flux in HEK cells expressing this protein. This modified fluorescent protein will facilitate investigations of dynamics of chloride ions and their mediation of cell function. Conclusions Modifications to YFP (EYFP-F46L/Q69K/H148Q/I152L/V163S/S175G/S205V/A206K (monomeric Cl-YFP) results in a photostable fluorescent protein that allows measurement of physiological changes in chloride concentration while remaining minimally affected by changes in pH. PMID:24901231

  11. Enhanced anti-tumor effect of a gene gun-delivered DNA vaccine encoding the human papillomavirus type 16 oncoproteins genetically fused to the herpes simplex virus glycoprotein D

    M.O. Diniz

    2011-05-01

    Full Text Available Anti-cancer DNA vaccines have attracted growing interest as a simple and non-invasive method for both the treatment and prevention of tumors induced by human papillomaviruses. Nonetheless, the low immunogenicity of parenterally administered vaccines, particularly regarding the activation of cytotoxic CD8+ T cell responses, suggests that further improvements in both vaccine composition and administration routes are still required. In the present study, we report the immune responses and anti-tumor effects of a DNA vaccine (pgD-E7E6E5 expressing three proteins (E7, E6, and E5 of the human papillomavirus type 16 genetically fused to the glycoprotein D of the human herpes simplex virus type 1, which was administered to mice by the intradermal (id route using a gene gun. A single id dose of pgD-E7E6E5 (2 µg/dose induced a strong activation of E7-specific interferon-γ (INF-γ-producing CD8+ T cells and full prophylactic anti-tumor effects in the vaccinated mice. Three vaccine doses inhibited tumor growth in 70% of the mice with established tumors. In addition, a single vaccine dose consisting of the co-administration of pgD-E7E6E5 and the vector encoding interleukin-12 or granulocyte-macrophage colony-stimulating factor further enhanced the therapeutic anti-tumor effects and conferred protection to 60 and 50% of the vaccinated mice, respectively. In conclusion, id administration of pgD-E7E6E5 significantly enhanced the immunogenicity and anti-tumor effects of the DNA vaccine, representing a promising administration route for future clinical trials.

  12. Calcium blood test

    ... page: //medlineplus.gov/ency/article/003477.htm Calcium blood test To use the sharing features on this page, please enable JavaScript. The calcium blood test measures the level of calcium in the blood. ...

  13. Calcium source (image)

    Getting enough calcium to keep bones from thinning throughout a person's life may be made more difficult if that person has ... as a tendency toward kidney stones, for avoiding calcium-rich food sources. Calcium deficiency also effects the ...

  14. Calcium Pyrophosphate Deposition (CPPD)

    ... Patient / Caregiver Diseases & Conditions Calcium Pyrophosphate Deposition (CPPD) Calcium Pyrophosphate Deposition (CPPD) Fast Facts The risk of ... young people, too. Proper diagnosis depends on detecting calcium pyrophosphate crystals in the fluid of an affected ...

  15. Calcium carbonate overdose

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Products that contain calcium carbonate are certain: Antacids (Tums, Chooz) Mineral supplements Hand lotions Vitamin and mineral supplements Other products may also contain ...

  16. Calcium and bones (image)

    Calcium is one of the most important minerals for the growth, maintenance, and reproduction of the human ... body, are continually being re-formed and incorporate calcium into their structure. Calcium is essential for the ...

  17. Calcium hydroxide poisoning

    Hydrate - calcium; Lime milk; Slaked lime ... Calcium hydroxide ... These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement ...

  18. Dopaminergic neurons encode a distributed, asymmetric representation of temperature in Drosophila.

    Tomchik, Seth M

    2013-01-30

    Dopaminergic circuits modulate a wide variety of innate and learned behaviors in animals, including olfactory associative learning, arousal, and temperature-preference behavior. It is not known whether distinct or overlapping sets of dopaminergic neurons modulate these behaviors. Here, I have functionally characterized the dopaminergic circuits innervating the Drosophila mushroom body with in vivo calcium imaging and conditional silencing of genetically defined subsets of neurons. Distinct subsets of PPL1 dopaminergic neurons innervating the vertical lobes of the mushroom body responded to decreases in temperature, but not increases, with rapidly adapting bursts of activity. PAM neurons innervating the horizontal lobes did not respond to temperature shifts. Ablation of the antennae and maxillary palps reduced, but did not eliminate, the responses. Genetic silencing of dopaminergic neurons innervating the vertical mushroom body lobes substantially reduced behavioral cold avoidance, but silencing smaller subsets of these neurons had no effect. These data demonstrate that overlapping dopaminergic circuits encode a broadly distributed, asymmetric representation of temperature that overlays regions implicated previously in learning, memory, and forgetting. Thus, diverse behaviors engage overlapping sets of dopaminergic neurons that encode multimodal stimuli and innervate a single anatomical target, the mushroom body.

  19. Calcium in Urine Test

    ... K. Brunner & Suddarth's Handbook of Laboratory and Diagnostic Tests. 2 nd Ed, Kindle. Philadelphia: Wolters Kluwer Health, Lippincott Williams & Wilkins; c2014. Calcium, Serum; Calcium and Phosphates, Urine; ...

  20. Transcellular transport of calcium

    Terepka, A R; Coleman, J R; Armbrecht, H J; Gunter, T E

    1976-01-01

    Studies of two calcium transporting epithelia, embryonic chick chorioallantoic membrane and the small intestine of rat and chick, have strongly suggested that the transfer of calcium across a cell involves processes distinctly different from intracellular calcium ion regulation. In the proposed model, transcellular calcium transport is considered as a specialized process developed only by certain cells in those tissues charged with bulk transfer of calcium. The overall effect of the endocytotic mechanism is bulk calcium movement across a cell, protection of mitochondria from exposure to high concentrations of calcium, and the avoidance of wide and potentially toxic fluctuations in cytosol ionic calcium levels. (MFB)

  1. Genetic and nongenetic variation in concentration of selenium, calcium, potassium, zinc, magnesium, and phosphorus in milk of Dutch Holstein-Friesian cows

    Hulzen, van K.J.E.; Sprong, R.C.; Meer, van der R.; Arendonk, van J.A.M.

    2009-01-01

    Minerals found in milk, such as Se, Ca, K, Zn, Mg, and P, contribute to several vital physiological processes. The aim of this study was to quantify the genetic variation in levels of Se, Ca, K, Zn, Mg, and P in milk and to quantify the between-herd variation in the levels of these minerals in milk.

  2. Landscape encodings enhance optimization.

    Konstantin Klemm

    Full Text Available Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state.

  3. Landscape Encodings Enhance Optimization

    Klemm, Konstantin; Mehta, Anita; Stadler, Peter F.

    2012-01-01

    Hard combinatorial optimization problems deal with the search for the minimum cost solutions (ground states) of discrete systems under strong constraints. A transformation of state variables may enhance computational tractability. It has been argued that these state encodings are to be chosen invertible to retain the original size of the state space. Here we show how redundant non-invertible encodings enhance optimization by enriching the density of low-energy states. In addition, smooth landscapes may be established on encoded state spaces to guide local search dynamics towards the ground state. PMID:22496860

  4. Non-invasive phenotyping and drug testing in single cardiomyocytes or beta-cells by calcium imaging and optogenetics.

    Yu-Fen Chang

    Full Text Available Identification of drug induced electrical instability of the heart curtails development, and introduction, of potentially proarrhythmic drugs. This problem usually requires complimentary contact based approaches such as patch-clamp electrophysiology combined with field stimulation electrodes to observe and control the cell. This produces data with high signal to noise but requires direct physical contact generally preventing high-throughput, or prolonged, phenotyping of single cells or tissues. Combining genetically encoded optogenetic control and spectrally compatible calcium indicator tools into a single adenoviral vector allows the analogous capability for cell control with simultaneous cellular phenotyping without the need for contact. This combination can be applied to single rodent primary adult cardiomyocytes, and human stem cell derived cardiomyocytes, enabling contactless small molecule evaluation for inhibitors of sodium, potassium and calcium channels suggesting it may be useful for early toxicity work. In pancreatic beta-cells it reveals the effects of glucose and the KATP inhibitor gliclazide.

  5. Blind encoding into qudits

    Shaari, J.S.; Wahiddin, M.R.B.; Mancini, S.

    2008-01-01

    We consider the problem of encoding classical information into unknown qudit states belonging to any basis, of a maximal set of mutually unbiased bases, by one party and then decoding by another party who has perfect knowledge of the basis. Working with qudits of prime dimensions, we point out a no-go theorem that forbids 'shift' operations on arbitrary unknown states. We then provide the necessary conditions for reliable encoding/decoding

  6. An encoding device and a method of encoding

    2012-01-01

    The present invention relates to an encoding device, such as an optical position encoder, for encoding input from an object, and a method for encoding input from an object, for determining a position of an object that interferes with light of the device. The encoding device comprises a light source...... in the area in the space and may interfere with the light, which interference may be encoded into a position or activation....

  7. Calcium sensing in exocytosis

    Gustavsson, Natalia; Wu, Bingbing; Han, Weiping

    2012-01-01

    an increase in intracellular calcium levels. Besides the triggering role, calcium signaling modulates the precise amount and kinetics of vesicle release. Thus, it is a central question to understand the molecular machineries responsible for calcium sensing in exocytosis. Here we provide an overview of our...... current understanding of calcium sensing in neurotransmitter release and hormone secretion....

  8. Calcium fluoride

    King, C.W.; Nestor, O.H.

    1989-01-01

    A new process for producing large, single, oriented crystals of calcium fluoride (CaF 2 ) has been developed which overcomes the limitations of current growing methods. This process has been reduced to practice and has yielded oriented crystals 17.5 x 17.5 x 5 cm 3 . Currently nearing completion is a system for producing 35 x 35 x 7.5 cm 3 single crystals. A scale up to one-meter-square is considered feasible. This crystal growing process makes possible the fabrication of very large CaF 2 windows. Suitability for very high power lasers, however, requires attention to properties beyond mere size. A process to generate higher purity growth stock (starting material) was also developed. The additional purification of the growth stock contributes to lower bulk absorption, the absence of color centers and increased radiation hardness. Also identified were several specific impurities which correlate with radiation hardness. A correlation was found between color centers induced by laser radiation and ionizing radiation. Other CaF 2 crystal properties such as tensile strength, absorption and laser damage thresholds were studied and are discussed

  9. All-optical functional synaptic connectivity mapping in acute brain slices using the calcium integrator CaMPARI.

    Zolnik, Timothy A; Sha, Fern; Johenning, Friedrich W; Schreiter, Eric R; Looger, Loren L; Larkum, Matthew E; Sachdev, Robert N S

    2017-03-01

    The genetically encoded fluorescent calcium integrator calcium-modulated photoactivatable ratiobetric integrator (CaMPARI) reports calcium influx induced by synaptic and neural activity. Its fluorescence is converted from green to red in the presence of violet light and calcium. The rate of conversion - the sensitivity to activity - is tunable and depends on the intensity of violet light. Synaptic activity and action potentials can independently initiate significant CaMPARI conversion. The level of conversion by subthreshold synaptic inputs is correlated to the strength of input, enabling optical readout of relative synaptic strength. When combined with optogenetic activation of defined presynaptic neurons, CaMPARI provides an all-optical method to map synaptic connectivity. The calcium-modulated photoactivatable ratiometric integrator (CaMPARI) is a genetically encoded calcium integrator that facilitates the study of neural circuits by permanently marking cells active during user-specified temporal windows. Permanent marking enables measurement of signals from large swathes of tissue and easy correlation of activity with other structural or functional labels. One potential application of CaMPARI is labelling neurons postsynaptic to specific populations targeted for optogenetic stimulation, giving rise to all-optical functional connectivity mapping. Here, we characterized the response of CaMPARI to several common types of neuronal calcium signals in mouse acute cortical brain slices. Our experiments show that CaMPARI is effectively converted by both action potentials and subthreshold synaptic inputs, and that conversion level is correlated to synaptic strength. Importantly, we found that conversion rate can be tuned: it is linearly related to light intensity. At low photoconversion light levels CaMPARI offers a wide dynamic range due to slower conversion rate; at high light levels conversion is more rapid and more sensitive to activity. Finally, we employed Ca

  10. Calcium signaling in liver.

    Gaspers, Lawrence D; Thomas, Andrew P

    2005-01-01

    In hepatocytes, hormones linked to the formation of the second messenger inositol 1,4,5-trisphosphate (InsP3) evoke transient increases or spikes in cytosolic free calcium ([Ca2+]i), that increase in frequency with the agonist concentration. These oscillatory Ca2+ signals are thought to transmit the information encoded in the extracellular stimulus to down-stream Ca2+-sensitive metabolic processes. We have utilized both confocal and wide field fluorescence microscopy techniques to study the InsP3-dependent signaling pathway at the cellular and subcellular levels in the intact perfused liver. Typically InsP3-dependent [Ca2+]i spikes manifest as Ca2+ waves that propagate throughout the entire cytoplasm and nucleus, and in the intact liver these [Ca2+]i increases are conveyed through gap junctions to encompass entire lobular units. The translobular movement of Ca2+ provides a means to coordinate the function of metabolic zones of the lobule and thus, liver function. In this article, we describe the characteristics of agonist-evoked [Ca2+]i signals in the liver and discuss possible mechanisms to explain the propagation of intercellular Ca2+ waves in the intact organ.

  11. Haploinsufficiency of the 22q11.2 microdeletion gene Mrpl40 disrupts short-term synaptic plasticity and working memory through dysregulation of mitochondrial calcium.

    Devaraju, P; Yu, J; Eddins, D; Mellado-Lagarde, M M; Earls, L R; Westmoreland, J J; Quarato, G; Green, D R; Zakharenko, S S

    2017-09-01

    Hemizygous deletion of a 1.5- to 3-megabase region on chromosome 22 causes 22q11.2 deletion syndrome (22q11DS), which constitutes one of the strongest genetic risks for schizophrenia. Mouse models of 22q11DS have abnormal short-term synaptic plasticity that contributes to working-memory deficiencies similar to those in schizophrenia. We screened mutant mice carrying hemizygous deletions of 22q11DS genes and identified haploinsufficiency of Mrpl40 (mitochondrial large ribosomal subunit protein 40) as a contributor to abnormal short-term potentiation (STP), a major form of short-term synaptic plasticity. Two-photon imaging of the genetically encoded fluorescent calcium indicator GCaMP6, expressed in presynaptic cytosol or mitochondria, showed that Mrpl40 haploinsufficiency deregulates STP via impaired calcium extrusion from the mitochondrial matrix through the mitochondrial permeability transition pore. This led to abnormally high cytosolic calcium transients in presynaptic terminals and deficient working memory but did not affect long-term spatial memory. Thus, we propose that mitochondrial calcium deregulation is a novel pathogenic mechanism of cognitive deficiencies in schizophrenia.

  12. A light- and calcium-gated transcription factor for imaging and manipulating activated neurons.

    Wang, Wenjing; Wildes, Craig P; Pattarabanjird, Tanyaporn; Sanchez, Mateo I; Glober, Gordon F; Matthews, Gillian A; Tye, Kay M; Ting, Alice Y

    2017-09-01

    Activity remodels neurons, altering their molecular, structural, and electrical characteristics. To enable the selective characterization and manipulation of these neurons, we present FLARE, an engineered transcription factor that drives expression of fluorescent proteins, opsins, and other genetically encoded tools only in the subset of neurons that experienced activity during a user-defined time window. FLARE senses the coincidence of elevated cytosolic calcium and externally applied blue light, which together produce translocation of a membrane-anchored transcription factor to the nucleus to drive expression of any transgene. In cultured rat neurons, FLARE gives a light-to-dark signal ratio of 120 and a high- to low-calcium signal ratio of 10 after 10 min of stimulation. Opsin expression permitted functional manipulation of FLARE-marked neurons. In adult mice, FLARE also gave light- and motor-activity-dependent transcription in the cortex. Due to its modular design, minute-scale temporal resolution, and minimal dark-state leak, FLARE should be useful for the study of activity-dependent processes in neurons and other cells that signal with calcium.

  13. Genetic Heterogeneity in Spondylo- epi- metaphyseal Dysplasias

    rme

    Human Genetics & Genome Research Division, National Research Centre and3 ... assessment, IQ, echocardiography, abdominopelvic ultrasound, serum level of calcium, phosphorus, alkaline ..... the brain showed cortical brain atrophy.

  14. NMDA receptors and memory encoding.

    Morris, Richard G M

    2013-11-01

    It is humbling to think that 30 years have passed since the paper by Collingridge, Kehl and McLennan showing that one of Jeff Watkins most interesting compounds, R-2-amino-5-phosphonopentanoate (d-AP5), blocked the induction of long-term potentiation in vitro at synapses from area CA3 of the hippocampus to CA1 without apparent effect on baseline synaptic transmission (Collingridge et al., 1983). This dissociation was one of the key triggers for an explosion of interest in glutamate receptors, and much has been discovered since that collectively contributes to our contemporary understanding of glutamatergic synapses - their biophysics and subunit composition, of the agonists and antagonists acting on them, and their diverse functions in different networks of the brain and spinal cord. It can be fairly said that Collingridge et al.'s (1983) observation was the stimulus that has led, on the one hand, to structural biological work at the atomic scale describing the key features of NMDA receptors that enables their coincidence function to happen; and, on the other, to work with whole animals investigating the contributions that calcium signalling via this receptor can have on rhythmical activities controlled by spinal circuits, memory encoding in the hippocampus (the topic of this article), visual cortical plasticity, sensitization in pain, and other functions. In this article, I lay out how my then interest in long-term potentiation (LTP) as a model of memory enabled me to recognise the importance of Collingridge et al.'s discovery - and how I and my colleagues endeavoured to take things forward in the area of learning and memory. This is in some respects a personal story, and I tell it as such. The idea that NMDA receptor activation is essential for memory encoding, though not for storage, took time to develop and to be accepted. Along the way, there have been confusions, challenges, and surprises surrounding the idea that activation of NMDA receptors can

  15. Calcium and magnesium determination

    Bhattacharya, S.K.

    1982-01-01

    The roles of calcium and magnesium in human health and disease have been extensively studied. Calcium and magnesium have been determined in biological specimens by atomic absorption spectroscopy using stiochiometric nitrous oxide-acetylene flame

  16. Fenoprofen calcium overdose

    ... page: //medlineplus.gov/ency/article/002649.htm Fenoprofen calcium overdose To use the sharing features on this page, please enable JavaScript. Fenoprofen calcium is a type of medicine called a nonsteroidal ...

  17. Calcium channel blocker overdose

    ... this page: //medlineplus.gov/ency/article/002580.htm Calcium-channel blocker overdose To use the sharing features on this page, please enable JavaScript. Calcium-channel blockers are a type of medicine used ...

  18. Calcium and Mitosis

    Hepler, P.

    1983-01-01

    Although the mechanism of calcium regulation is not understood, there is evidence that calcium plays a role in mitosis. Experiments conducted show that: (1) the spindle apparatus contains a highly developed membrane system that has many characteristics of sarcoplasmic reticulum of muscle; (2) this membrane system contains calcium; and (3) there are ionic fluxes occurring during mitosis which can be seen by a variety of fluorescence probes. Whether the process of mitosis can be modulated by experimentally modulating calcium is discussed.

  19. Calcium en cardioplegie

    Ruigrok, T.J.C.; Meijler, F.L.

    1985-01-01

    Coronary perfusion with a calcium-free solution, followed by reperfusion with a calcium containing solution, may result in acute myocardial cell death and in irreversible loss of the e1ectrical and mechanical activity of the heart. This phenomenon is known as the calcium paradox. A number of

  20. Applications of Genetic Programming

    Gaunholt, Hans; Toma, Laura

    1996-01-01

    In this report a study of genetic programming (GP) has been performed with respect to a number of applications such as Symbolic function regression, Solving Symbolic Differential Equations, Image encoding, the ant problem etc.......In this report a study of genetic programming (GP) has been performed with respect to a number of applications such as Symbolic function regression, Solving Symbolic Differential Equations, Image encoding, the ant problem etc....

  1. Calcium dynamics in root cells of Arabidopsis thaliana visualized with selective plane illumination microscopy.

    Alex Costa

    Full Text Available Selective Plane Illumination Microscopy (SPIM is an imaging technique particularly suited for long term in-vivo analysis of transparent specimens, able to visualize small organs or entire organisms, at cellular and eventually even subcellular resolution. Here we report the application of SPIM in Calcium imaging based on Förster Resonance Energy Transfer (FRET. Transgenic Arabidopsis plants expressing the genetically encoded-FRET-based Ca(2+ probe Cameleon, in the cytosol or nucleus, were used to demonstrate that SPIM enables ratiometric fluorescence imaging at high spatial and temporal resolution, both at tissue and single cell level. The SPIM-FRET technique enabled us to follow nuclear and cytosolic Ca(2+ dynamics in Arabidopsis root tip cells, deep inside the organ, in response to different stimuli. A relevant physiological phenomenon, namely Ca(2+ signal percolation, predicted in previous studies, has been directly visualized.

  2. Parallel encoders for pixel detectors

    Nikityuk, N.M.

    1991-01-01

    A new method of fast encoding and determining the multiplicity and coordinates of fired pixels is described. A specific example construction of parallel encodes and MCC for n=49 and t=2 is given. 16 refs.; 6 figs.; 2 tabs

  3. Interactions of Mitochondria/Metabolism and Calcium Regulation in Alzheimer's Disease: A Calcinist Point of View.

    Gibson, Gary E; Thakkar, Ankita

    2017-06-01

    Decades of research suggest that alterations in calcium are central to the pathophysiology of Alzheimer's Disease (AD). Highly reproducible changes in calcium dynamics occur in cells from patients with both genetic and non-genetic forms of AD relative to controls. The most robust change is an exaggerated release of calcium from internal stores. Detailed analysis of these changes in animal and cell models of the AD-causing presenilin mutations reveal robust changes in ryanodine receptors, inositol tris-phosphate receptors, calcium leak channels and store activated calcium entry. Similar anomalies in calcium result when AD-like changes in mitochondrial enzymes or oxidative stress are induced experimentally. The calcium abnormalities can be directly linked to the altered tau phosphorylation, amyloid precursor protein processing and synaptic dysfunction that are defining features of AD. A better understanding of these changes is required before using calcium abnormalities as therapeutic targets.

  4. Differential calcium sensitivity in NaV 1.5 mixed syndrome mutants.

    Abdelsayed, Mena; Baruteau, Alban-Elouen; Gibbs, Karen; Sanatani, Shubhayan; Krahn, Andrew D; Probst, Vincent; Ruben, Peter C

    2017-09-15

    SCN5a mutations may express gain-of-function (Long QT Syndrome-3), loss-of-function (Brugada Syndrome 1) or both (mixed syndromes), depending on the mutation and environmental triggers. One such trigger may be an increase in cytosolic calcium, accompanying exercise. Many mixed syndromes mutants, including ∆KPQ, E1784K, 1795insD and Q1909R, are found in calcium-sensitive regions. Elevated cytosolic calcium attenuates gain-of-function properties in ∆KPQ, 1795insD and Q1909R, but not in E1784K. By contrast, elevated cytosolic calcium further exacerbates gain-of-function in E1784K by destabilizing slow inactivation. Action potential modelling, using a modified O'Hara Rudy model, suggests that elevated heart rate rescues action potential duration in ∆KPQ, 1795insD and Q1909R, but not in E1784K. Action potential simulations suggest that E1784K carriers have an increased intracellular sodium-to-calcium ratio under bradycardia and tachycardia conditions. Elevated cytosolic calcium, which is common during high heart rates, ameliorates or exacerbates the mixed syndrome phenotype depending on the genetic signature. Inherited arrhythmias may arise from mutations in the gene for SCN5a, which encodes the cardiac voltage-gated sodium channel, Na V 1.5. Mutants in Na V 1.5 result in Brugada Syndrome (BrS1), Long-QT Syndrome (LQT3) or mixed syndromes (an overlap of BrS1/LQT3). Exercise is a potential arrhythmogenic trigger in mixed syndromes. We aimed to determine the effects of elevated cytosolic calcium, which is common during exercise, in mixed syndrome Na V 1.5 mutants. We used whole-cell patch clamp to assess the biophysical properties of Na V 1.5 wild-type (WT), ∆KPQ, E1784K, 1795insD and Q1909R mutants in human embryonic kidney 293 cells transiently transfected with the Na V 1.5 α subunit (WT or mutants), β1 subunit and enhanced green fluorescent protein. Voltage-dependence and kinetics were measured at cytosolic calcium levels of approximately 0, 500 and 2500

  5. Calcium absorption and achlorhydria

    Recker, R.R.

    1985-01-01

    Defective absorption of calcium has been thought to exist in patients with achlorhydria. The author compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects. Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier. Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001). Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant). Absorption of calcium from carbonate in patients with achlorhydria was significantly lower than in the normal subjects and was lower than absorption from citrate in either group; absorption from citrate in those with achlorhydria was significantly higher than in the normal subjects, as well as higher than absorption from carbonate in either group. Administration of calcium carbonate as part of a normal breakfast resulted in completely normal absorption in the achlorhydric subjects. These results indicate that calcium absorption from carbonate is impaired in achlorhydria under fasting conditions. Since achlorhydria is common in older persons, calcium carbonate may not be the ideal dietary supplement

  6. Calcium and Egg Activation in Drosophila

    Sartain, Caroline V.; Wolfner, Mariana F.

    2012-01-01

    Summary In many animals, a rise in intracellular calcium levels is the trigger for egg activation, the process by which an arrested mature oocyte transitions to prepare for embryogenesis. In nearly all animals studied to date, this calcium rise, and thus egg activation, is triggered by the fertilizing sperm. However in the insects that have been examined, fertilization is not necessary to activate their oocytes. Rather, these insects’ eggs activate as they transit through the female’s reproductive tract, regardless of male contribution. Recent studies in Drosophila have shown that egg activation nevertheless requires calcium and that the downstream events and molecules of egg activation are also conserved, despite the difference in initial trigger. Genetic studies have uncovered essential roles for the calcium-dependent enzyme calcineurin and its regulator calcipressin, and have hinted at roles for calmodulin, in Drosophila egg activation. Physiological and in vitro studies have led to a model in which mechanical forces that impact the Drosophila oocyte as it moves through the reproductive tract triggers the influx of calcium from the external environment, thereby initiating egg activation. Future research will aim to test this model, as well as to determine the spatiotemporal dynamics of cytoplasmic calcium flux and mode of signal propagation in this unique system. PMID:23218670

  7. Calcium channel blocker poisoning

    Miran Brvar

    2005-04-01

    Full Text Available Background: Calcium channel blockers act at L-type calcium channels in cardiac and vascular smooth muscles by preventing calcium influx into cells with resultant decrease in vascular tone and cardiac inotropy, chronotropy and dromotropy. Poisoning with calcium channel blockers results in reduced cardiac output, bradycardia, atrioventricular block, hypotension and shock. The findings of hypotension and bradycardia should suggest poisoning with calcium channel blockers.Conclusions: Treatment includes immediate gastric lavage and whole-bowel irrigation in case of ingestion of sustainedrelease products. All patients should receive an activated charcoal orally. Specific treatment includes calcium, glucagone and insulin, which proved especially useful in shocked patients. Supportive care including the use of catecholamines is not always effective. In the setting of failure of pharmacological therapy transvenous pacing, balloon pump and cardiopulmonary by-pass may be necessary.

  8. Dengue and Calcium

    Shivanthan, Mitrakrishnan C; Rajapakse, Senaka

    2014-01-01

    Dengue is potentially fatal unless managed appropriately. No specific treatment is available and the mainstay of treatment is fluid management with careful monitoring, organ support, and correction of metabolic derangement. Evidence with regards to the role of calcium homeostasis in dengue is limited. Low blood calcium levels have been demonstrated in dengue infection and hypocalcemia maybe more pronounced in more severe forms. The cause of hypocalcemia is likely to be multifactorial. Calcium...

  9. Calcium Channel Blockers

    ... Certain calcium channel blockers interact with grapefruit products. Kaplan NM, et al. Treatment of hypertension: Drug therapy. In: Kaplan's Clinical Hypertension. 11th ed. Philadelphia, Pa.: Wolters Kluwer ...

  10. Purification and Genetic Characterization of Enterocin I from Enterococcus faecium 6T1a, a Novel Antilisterial Plasmid-Encoded Bacteriocin Which Does Not Belong to the Pediocin Family of Bacteriocins

    Floriano, Belén; Ruiz-Barba, José L.; Jiménez-Díaz, Rufino

    1998-01-01

    Enterocin I (ENTI) is a novel bacteriocin produced by Enterococcus faecium 6T1a, a strain originally isolated from a Spanish-style green olive fermentation. The bacteriocin is active against many olive spoilage and food-borne gram-positive pathogenic bacteria, including clostridia, propionibacteria, and Listeria monocytogenes. ENTI was purified to homogeneity by ammonium sulfate precipitation, binding to an SP-Sepharose fast-flow column, and phenyl-Sepharose CL-4B and C2/C18 reverse-phase chromatography. The purification procedure resulted in a final yield of 954% and a 170,000-fold increase in specific activity. The primary structure of ENTI was determined by amino acid and nucleotide sequencing. ENTI consists of 44 amino acids and does not show significant sequence similarity with any other previously described bacteriocin. Sequencing of the entI structural gene, which is located on the 23-kb plasmid pEF1 of E. faecium 6T1a, revealed the absence of a leader peptide at the N-terminal region of the gene product. A second open reading frame, ORF2, located downstream of entI, encodes a putative protein that is 72.7% identical to ENTI. entI and ORF2 appear to be cotranscribed, yielding an mRNA of ca. 0.35 kb. A gene encoding immunity to ENTI was not identified. However, curing experiments demonstrated that both enterocin production and immunity are conferred by pEF1. PMID:9835578

  11. Genome-Wide Association Study of Calcium Accumulation in Grains of European Wheat Cultivars

    Dalia Z. Alomari

    2017-10-01

    Full Text Available Mineral concentrations in cereals are important for human health, especially for people who depend mainly on consuming cereal diet. In this study, we carried out a genome-wide association study (GWAS of calcium concentrations in wheat (Triticum aestivum L. grains using a European wheat diversity panel of 353 varieties [339 winter wheat (WW plus 14 of spring wheat (SW] and phenotypic data based on two field seasons. High genotyping densities of single-nucleotide polymorphism (SNP markers were obtained from the application of the 90k iSELECT ILLUMINA chip and a 35k Affymetrix chip. Inductively coupled plasma optical emission spectrometry (ICP-OES was used to measure the calcium concentrations of the wheat grains. Best linear unbiased estimates (BLUEs for calcium were calculated across the seasons and ranged from 288.20 to 647.50 among the varieties (μg g-1 DW with a mean equaling 438.102 (μg g-1 DW, and the heritability was 0.73. A total of 485 SNP marker–trait associations (MTAs were detected in data obtained from grains cultivated in both of the two seasons and BLUE values by considering associations with a -log10 (P-value ≥3.0. Among these SNP markers, we detected 276 markers with a positive allele effect and 209 markers with a negative allele effect. These MTAs were found on all chromosomes except chromosomes 3D, 4B, and 4D. The most significant association was located on chromosome 5A (114.5 cM and was linked to a gene encoding cation/sugar symporter activity as a potential candidate gene. Additionally, a number of candidate genes for the uptake or transport of calcium were located near significantly associated SNPs. This analysis highlights a number of genomic regions and candidate genes for further analysis as well as the challenges faced when mapping environmentally variable traits in genetically highly diverse variety panels. The research demonstrates the feasibility of the GWAS approach for illuminating the genetic architecture of

  12. Selecting Operations for Assembler Encoding

    Tomasz Praczyk

    2010-04-01

    Full Text Available Assembler Encoding is a neuro-evolutionary method in which a neural network is represented in the form of a simple program called Assembler Encoding Program. The task of the program is to create the so-called Network Definition Matrix which maintains all the information necessary to construct the network. To generate Assembler Encoding Programs and the subsequent neural networks evolutionary techniques are used.
    The performance of Assembler Encoding strongly depends on operations used in Assembler Encoding Programs. To select the most effective operations, experiments in the optimization and the predator-prey problem were carried out. In the experiments, Assembler Encoding Programs equipped with different types of operations were tested. The results of the tests are presented at the end of the paper.

  13. Acidosis and Urinary Calcium Excretion

    Alexander, R Todd; Cordat, Emmanuelle; Chambrey, Régine

    2016-01-01

    Metabolic acidosis is associated with increased urinary calcium excretion and related sequelae, including nephrocalcinosis and nephrolithiasis. The increased urinary calcium excretion induced by metabolic acidosis predominantly results from increased mobilization of calcium out of bone and inhibi...

  14. Calcium D-saccharate

    Garcia, André Castilho; Hedegaard, Martina Vavrusova; Skibsted, Leif Horsfelt

    2016-01-01

    Molar conductivity of saturated aqueous solutions of calcium d-saccharate, used as a stabilizer of beverages fortified with calcium d-gluconate, increases strongly upon dilution, indicating complex formation between calcium and d-saccharate ions, for which, at 25 °C, Kassoc = 1032 ± 80, ΔHassoc......° = -34 ± 6 kJ mol-1, and ΔSassoc° = -55 ± 9 J mol-1 K-1, were determined electrochemically. Calcium d-saccharate is sparingly soluble, with a solubility product, Ksp, of (6.17 ± 0.32) × 10-7 at 25 °C, only moderately increasing with the temperature: ΔHsol° = 48 ± 2 kJ mol-1, and ΔSassoc° = 42 ± 7 J mol-1...... K-1. Equilibria in supersaturated solutions of calcium d-saccharate seem only to adjust slowly, as seen from calcium activity measurements in calcium d-saccharate solutions made supersaturated by cooling. Solutions formed by isothermal dissolution of calcium d-gluconate in aqueous potassium d...

  15. Calcium metabolism in birds.

    de Matos, Ricardo

    2008-01-01

    Calcium is one of the most important plasma constituents in mammals and birds. It provides structural strength and support (bones and eggshell) and plays vital roles in many of the biochemical reactions in the body. The control of calcium metabolism in birds is highly efficient and closely regulated in a number of tissues, primarily parathyroid gland, intestine, kidney, and bone. The hormones with the greatest involvement in calcium regulation in birds are parathyroid hormone, 1,25-dihydroxyvitamin D(3) (calcitriol), and estrogen, with calcitonin playing a minor and uncertain role. The special characteristics of calcium metabolism in birds, mainly associated with egg production, are discussed, along with common clinical disorders secondary to derangements in calcium homeostasis.

  16. HYPERTHERMIA, INTRACELLULAR FREE CALCIUM AND CALCIUM IONOPHORES

    STEGE, GJJ; WIERENGA, PK; KAMPINGA, HH; KONINGS, AWT

    1993-01-01

    It is shown that heat-induced increase of intracellular calcium does not correlate with hyperthermic cell killing. Six different cell lines were investigated; in four (EAT, HeLa S3, L5178Y-R and L5178Y-S) heat treatments killing 90% of the cells did not affect the levels of intracellular free

  17. Calcium response to vitamin D supplementation

    Francisco R. Spivacow

    2018-01-01

    Full Text Available Several studies show the importance of serum vitamin D sufficient levels to prevent multiple chronic diseases. However, vitamin D supplementation and its effects on urine calcium excretion remain controversial. The objective of this prospective and interventional study was to evaluate urine calcium excretion in women with normal calciuria or hypercalciuria, once serum vitamin D sufficiency was achieved. We studied 63 women with idiopathic hypercalciuria, (9 with renal lithiasis and 50 normocalciuric women. Both groups had serum vitamin D levels low (deficiency or insufficiency. Baseline urine calcium excretion was measured before being supplemented with vitamin D2 or D3 weekly or vitamin D3 100.000 IU monthly. Once serum vitamin D levels were corrected achieving at least 30 ng/ml, a second urine calcium excretion was obtained. Although in the whole sample we did not observe significant changes in urine calcium excretion according to the way of supplementation, some of those with weekly supplementation had significant higher urine calcium excretion, 19% (n = 12 of hypercalciuric women and 12% (n = 6 of the normocalciuric group. Monthly doses, also showed higher urine calcium excretion in 40% of hypercalciuric women (n = 4/10 and in 44% (n = 4/9 of the renal lithiasis hypercalciuric patients. In conclusion, different ways of vitamin D supplementation and adequate serum levels are safe in most patients, although it should be taken into account a subgroup, mainly with monthly loading doses, that could increase the calciuria significantly eventually rising renal lithiasis risk or bone mass loss, if genetically predisposed.

  18. Identification and characterization of a gene encoding a putative ...

    2012-10-30

    Oct 30, 2012 ... Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China. 2Institute of ... Its encoding gene is an essential candidate for oil crops to .... higher level in leaves than in other organs (Kim and Huang. 2004) ...

  19. DIHYDROPYRIDINE CALCIUM- CHANNELBLOCKERSFOR ...

    Furthermore, the controversy over the role of calci~-channel blockers as first-line ..... group trials while fully accounting for placebo effects as well as interindividual ..... Reducing calcium overload in the ischemic brain. N Engl JMed. 1999; 341 ...

  20. Calcium and Your Child

    ... calcium-set tofu edamame (soybeans) broccoli, collard greens, kale, chard, Chinese cabbage, and other leafy greens almonds ... more dark green, leafy vegetables (such as broccoli, kale, collard greens, or Chinese cabbage) with meals. Kids ...

  1. Improved humoral and cellular immune response against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatites B surface antigen

    Fomsgaard, A.; Nielsen, H.V.; Bryder, K.

    1998-01-01

    response and a uniform strong anti-HBs CTL response already 1 week p.i. in all mice. DNA vaccination with the chimeric MN V2/HBsAg plasmid elicited humoral responses against both viruses within 3-6 weeks which peaked at 6-12 weeks and remained stable for at least 25 weeks. In addition, specific CTL...... responses were induced in all mice against both MN V3 and HBsAg already within the first 3 weeks, lasting at least 11 weeks. Thus, HBsAg acts as a `genetic vaccine adjuvant' augmenting and accelerating the cellular and humoral immune response against the inserted MN V3 loop. Such chimeric HIV-HbsAg plasmid...

  2. Improved humoral and cellular immune responses against the gp120 V3 loop of HIV-1 following genetic immunization with a chimeric DNA vaccine encoding the V3 inserted into the hepatitis B surface antigen

    Fomsgaard, A; Nielsen, H V; Bryder, K

    1998-01-01

    response and a uniform strong anti-HBs CTL response already 1 week p.i. in all mice. DNA vaccination with the chimeric MN V3/HBsAg plasmid elicited humoral responses against both viruses within 3-6 weeks which peaked at 6-12 weeks and remained stable for at least 25 weeks. In addition, specific CTL...... responses were induced in all mice against both MN V3 and HBsAg already within the first 3 weeks, lasting at least 11 weeks. Thus, HBsAg acts as a 'genetic vaccine adjuvant' augmenting and accelerating the cellular and humoral immune response against the inserted MN V3 loop. Such chimeric HIV-HBsAg plasmid...

  3. Rapid and Localized Mechanical Stimulation and Adhesion Assay: TRPM7 Involvement in Calcium Signaling and Cell Adhesion.

    Wagner Shin Nishitani

    Full Text Available A cell mechanical stimulation equipment, based on cell substrate deformation, and a more sensitive method for measuring adhesion of cells were developed. A probe, precisely positioned close to the cell, was capable of a vertical localized mechanical stimulation with a temporal frequency of 207 Hz, and strain magnitude of 50%. This setup was characterized and used to probe the response of Human Umbilical Endothelial Vein Cells (HUVECs in terms of calcium signaling. The intracellular calcium ion concentration was measured by the genetically encoded Cameleon biosensor, with the Transient Receptor Potential cation channel, subfamily M, member 7 (TRPM7 expression inhibited. As TRPM7 expression also regulates adhesion, a relatively simple method for measuring adhesion of cells was also developed, tested and used to study the effect of adhesion alone. Three adhesion conditions of HUVECs on polyacrylamide gel dishes were compared. In the first condition, the substrate is fully treated with Sulfo-SANPAH crosslinking and fibronectin. The other two conditions had increasingly reduced adhesion: partially treated (only coated with fibronectin, with no use of Sulfo-SANPAH, at 5% of the normal amount and non-treated polyacrylamide gels. The cells showed adhesion and calcium response to the mechanical stimulation correlated to the degree of gel treatment: highest for fully treated gels and lowest for non-treated ones. TRPM7 inhibition by siRNA on HUVECs caused an increase in adhesion relative to control (no siRNA treatment and non-targeting siRNA, but a decrease to 80% of calcium response relative to non-targeting siRNA which confirms the important role of TRPM7 in mechanotransduction despite the increase in adhesion.

  4. Calcium binding by dietary fibre

    James, W.P.T.; Branch, W.J.; Southgate, D.A.T.

    1978-01-01

    Dietary fibre from plants low in phytate bound calcium in proportion to its uronic-acid content. This binding by the non-cellulosic fraction of fibre reduces the availability of calcium for small-intestinal absorption, but the colonic microbial digestion of uronic acids liberates the calcium. Thus the ability to maintain calcium balance on high-fibre diets may depend on the adaptive capacity on the colon for calcium. (author)

  5. Association of genetic variants in the promoter region of genes encoding p22phox (CYBA and glutamate cysteine ligase catalytic subunit (GCLC and renal disease in patients with type 1 diabetes mellitus

    Pavin Elizabeth J

    2011-09-01

    Full Text Available Abstract Background Oxidative stress is recognized as a major pathogenic factor of cellular damage caused by hyperglycemia. NOX/NADPH oxidases generate reactive oxygen species and NOX1, NOX2 and NOX4 isoforms are expressed in kidney and require association with subunit p22phox (encoded by the CYBA gene. Increased expression of p22phox was described in animal models of diabetic nephropathy. In the opposite direction, glutathione is one of the main endogenous antioxidants whose plasmatic concentrations were reported to be reduced in diabetes patients. The aim of the present investigation was to test whether functional single nucleotide polymorphisms (SNPs in genes involved in the generation of NADPH-dependent O2•- (-675 T → A in CYBA, unregistered and in glutathione metabolism (-129 C → T in GCLC [rs17883901] and -65 T → C in GPX3 [rs8177412] confer susceptibility to renal disease in type 1 diabetes patients. Methods 401 patients were sorted into two groups according to the presence (n = 104 or absence (n = 196 of overt diabetic nephropathy or according to glomerular filtration rate (GFR estimated by Modification of Diet in Renal Disease (MDRD equation: ≥ 60 mL (n = 265 or 2 (n = 136 and were genotyped. Results No differences were found in the frequency of genotypes between diabetic and non-diabetic subjects. The frequency of GFR CYBA genotypes T/A+A/A (18.7% than in the group carrying the T/T genotype (35.3% (P = 0.0143 and the frequency of GFR GCLC genotypes C/T+T/T (47.1% than in the group carrying the C/C genotype (31.1% (p = 0.0082. Logistic regression analysis identified the presence of at least one A allele of the CYBA SNP as an independent protection factor against decreased GFR (OR = 0.38, CI95% 0.14-0.88, p = 0.0354 and the presence of at least one T allele of the GCLC rs17883901 SNP as an independent risk factor for decreased GFR (OR = 2.40, CI95% 1.27-4.56, p = 0.0068. Conclusions The functional SNPs CYBA -675 T → A and

  6. A model of propagating calcium-induced calcium release mediated by calcium diffusion

    Backx, P. H.; de Tombe, P. P.; van Deen, J. H.; Mulder, B. J.; ter Keurs, H. E.

    1989-01-01

    The effect of sudden local fluctuations of the free sarcoplasmic [Ca++]i in cardiac cells on calcium release and calcium uptake by the sarcoplasmic reticulum (SR) was calculated with the aid of a simplified model of SR calcium handling. The model was used to evaluate whether propagation of calcium

  7. [Calcium suppletion for patients who use gastric acid inhibitors: calcium citrate or calcium carbonate?].

    Jonge, H.J. de; Gans, R.O.; Huls, G.A.

    2012-01-01

    Various calcium supplements are available for patients who have an indication for calcium suppletion. American guidelines and UpToDate recommend prescribing calcium citrate to patients who use antacids The rationale for this advice is that water-insoluble calcium carbonate needs acid for adequate

  8. Analysing and Comparing Encodability Criteria

    Kirstin Peters

    2015-08-01

    Full Text Available Encodings or the proof of their absence are the main way to compare process calculi. To analyse the quality of encodings and to rule out trivial or meaningless encodings, they are augmented with quality criteria. There exists a bunch of different criteria and different variants of criteria in order to reason in different settings. This leads to incomparable results. Moreover it is not always clear whether the criteria used to obtain a result in a particular setting do indeed fit to this setting. We show how to formally reason about and compare encodability criteria by mapping them on requirements on a relation between source and target terms that is induced by the encoding function. In particular we analyse the common criteria full abstraction, operational correspondence, divergence reflection, success sensitiveness, and respect of barbs; e.g. we analyse the exact nature of the simulation relation (coupled simulation versus bisimulation that is induced by different variants of operational correspondence. This way we reduce the problem of analysing or comparing encodability criteria to the better understood problem of comparing relations on processes.

  9. Calcium in plant cells

    V. V. Schwartau

    2014-04-01

    Full Text Available The paper gives the review on the role of calcium in many physiological processes of plant organisms, including growth and development, protection from pathogenic influences, response to changing environmental factors, and many other aspects of plant physiology. Initial intake of calcium ions is carried out by Ca2+-channels of plasma membrane and they are further transported by the xylem owing to auxins’ attractive ability. The level of intake and selectivity of calcium transport to ove-ground parts of the plant is controlled by a symplast. Ca2+enters to the cytoplasm of endoderm cells through calcium channels on the cortical side of Kaspary bands, and is redistributed inside the stele by the symplast, with the use of Ca2+-АТPases and Ca2+/Н+-antiports. Owing to regulated expression and activity of these calcium transporters, calclum can be selectively delivered to the xylem. Important role in supporting calcium homeostasis is given to the vacuole which is the largest depo of calcium. Regulated quantity of calcium movement through the tonoplast is provided by a number of potential-, ligand-gated active transporters and channels, like Ca2+-ATPase and Ca2+/H+ exchanger. They are actively involved in the inactivation of the calcium signal by pumping Ca2+ to the depo of cells. Calcium ATPases are high affinity pumps that efficiently transfer calcium ions against the concentration gradient in their presence in the solution in nanomolar concentrations. Calcium exchangers are low affinity, high capacity Ca2+ transporters that are effectively transporting calcium after raising its concentration in the cell cytosol through the use of protons gradients. Maintaining constant concentration and participation in the response to stimuli of different types also involves EPR, plastids, mitochondria, and cell wall. Calcium binding proteins contain several conserved sequences that provide sensitivity to changes in the concentration of Ca2+ and when you

  10. New Role of P/Q-type Voltage-gated Calcium Channels

    Hansen, Pernille B L

    2015-01-01

    Voltage-gated calcium channels are important for the depolarization-evoked contraction of vascular smooth muscle cells (SMCs), with L-type channels being the classical channel involved in this mechanism. However, it has been demonstrated that the CaV2.1 subunit, which encodes a neuronal isoform...... of the voltage-gated calcium channels (P/Q-type), is also expressed and contributes functionally to contraction of renal blood vessels in both mice and humans. Furthermore, preglomerular vascular SMCs and aortic SMCs coexpress L-, P-, and Q-type calcium channels within the same cell. Calcium channel blockers...... are widely used as pharmacological treatments. However, calcium channel antagonists vary in their selectivity for the various calcium channel subtypes, and the functional contribution from P/Q-type channels as compared with L-type should be considered. Confirming the presence of P/Q-type voltage...

  11. Genetic Variants Associated with Circulating Parathyroid Hormone.

    Robinson-Cohen, Cassianne; Lutsey, Pamela L; Kleber, Marcus E; Nielson, Carrie M; Mitchell, Braxton D; Bis, Joshua C; Eny, Karen M; Portas, Laura; Eriksson, Joel; Lorentzon, Mattias; Koller, Daniel L; Milaneschi, Yuri; Teumer, Alexander; Pilz, Stefan; Nethander, Maria; Selvin, Elizabeth; Tang, Weihong; Weng, Lu-Chen; Wong, Hoi Suen; Lai, Dongbing; Peacock, Munro; Hannemann, Anke; Völker, Uwe; Homuth, Georg; Nauk, Matthias; Murgia, Federico; Pattee, Jack W; Orwoll, Eric; Zmuda, Joseph M; Riancho, Jose Antonio; Wolf, Myles; Williams, Frances; Penninx, Brenda; Econs, Michael J; Ryan, Kathleen A; Ohlsson, Claes; Paterson, Andrew D; Psaty, Bruce M; Siscovick, David S; Rotter, Jerome I; Pirastu, Mario; Streeten, Elizabeth; März, Winfried; Fox, Caroline; Coresh, Josef; Wallaschofski, Henri; Pankow, James S; de Boer, Ian H; Kestenbaum, Bryan

    2017-05-01

    Parathyroid hormone (PTH) is a primary calcium regulatory hormone. Elevated serum PTH concentrations in primary and secondary hyperparathyroidism have been associated with bone disease, hypertension, and in some studies, cardiovascular mortality. Genetic causes of variation in circulating PTH concentrations are incompletely understood. We performed a genome-wide association study of serum PTH concentrations among 29,155 participants of European ancestry from 13 cohort studies ( n =22,653 and n =6502 in discovery and replication analyses, respectively). We evaluated the association of single nucleotide polymorphisms (SNPs) with natural log-transformed PTH concentration adjusted for age, sex, season, study site, and principal components of ancestry. We discovered associations of SNPs from five independent regions with serum PTH concentration, including the strongest association with rs6127099 upstream of CYP24A1 ( P =4.2 × 10 -53 ), a gene that encodes the primary catabolic enzyme for 1,25-dihydroxyvitamin D and 25-dihydroxyvitamin D. Each additional copy of the minor allele at this SNP associated with 7% higher serum PTH concentration. The other SNPs associated with serum PTH concentration included rs4074995 within RGS14 ( P =6.6 × 10 -17 ), rs219779 adjacent to CLDN14 ( P =3.5 × 10 -16 ), rs4443100 near RTDR1 ( P =8.7 × 10 -9 ), and rs73186030 near CASR ( P =4.8 × 10 -8 ). Of these five SNPs, rs6127099, rs4074995, and rs219779 replicated. Thus, common genetic variants located near genes involved in vitamin D metabolism and calcium and renal phosphate transport associated with differences in circulating PTH concentrations. Future studies could identify the causal variants at these loci, and the clinical and functional relevance of these variants should be pursued. Copyright © 2017 by the American Society of Nephrology.

  12. Calcium Biofortification: Three Pronged Molecular Approaches for Dissecting Complex Trait of Calcium Nutrition in Finger Millet (Eleusine coracana) for Devising Strategies of Enrichment of Food Crops.

    Sharma, Divya; Jamra, Gautam; Singh, Uma M; Sood, Salej; Kumar, Anil

    2016-01-01

    Calcium is an essential macronutrient for plants and animals and plays an indispensable role in structure and signaling. Low dietary intake of calcium in humans has been epidemiologically linked to various diseases which can have serious health consequences over time. Major staple food-grains are poor source of calcium, however, finger millet [ Eleusine coracana (L.) Gaertn.], an orphan crop has an immense potential as a nutritional security crop due to its exceptionally high calcium content. Understanding the existing genetic variation as well as molecular mechanisms underlying the uptake, transport, accumulation of calcium ions (Ca 2+ ) in grains is of utmost importance for development of calcium bio-fortified crops. In this review, we have discussed molecular mechanisms involved in calcium accumulation and transport thoroughly, emphasized the role of molecular breeding, functional genomics and transgenic approaches to understand the intricate mechanism of calcium nutrition in finger millet. The objective is to provide a comprehensive up to date account of molecular mechanisms regulating calcium nutrition and highlight the significance of bio-fortification through identification of potential candidate genes and regulatory elements from finger millet to alleviate calcium malnutrition. Hence, finger millet could be used as a model system for explaining the mechanism of elevated calcium (Ca 2+ ) accumulation in its grains and could pave way for development of nutraceuticals or designer crops.

  13. Genetic Diversity of the fliC Genes Encoding the Flagellar Antigen H19 of Escherichia coli and Application to the Specific Identification of Enterohemorrhagic E. coli O121:H19

    Beutin, Lothar; Delannoy, Sabine

    2015-01-01

    Enterohemorrhagic Escherichia coli (EHEC) O121:H19 belong to a specific clonal type distinct from other classical EHEC and major enteropathogenic E. coli groups and is regarded as one of the major EHEC serogroups involved in severe infections in humans. Sequencing of the fliC genes associated with the flagellar antigen H19 (fliCH19) revealed the genetic diversity of the fliCH19 gene sequences in E. coli. A cluster analysis of 12 fliCH19 sequences, 4 from O121 and 8 from non-O121 E. coli strains, revealed five different genotypes. All O121:H19 strains fell into one cluster, whereas a second cluster was formed by five non-O121:H19 strains. Cluster 1 and cluster 2 strains differ by 27 single nucleotide exchanges in their fliCH19 genes (98.5% homology). Based on allele discrimination of the fliCH19 genes, a real-time PCR test was designed for specific identification of EHEC O121:H19. The O121 fliCH19 PCR tested negative in 73 E. coli H19 strains that belonged to serogroups other than O121, including 28 different O groups, O-nontypeable H19, and O-rough:H19 strains. The O121 fliCH19 PCR reacted with all 16 tested O121:H19 strains and 1 O-rough:H19 strain which was positive for the O121 wzx gene. A cross-reaction was observed only with E. coli H32 strains which share sequence similarities in the target region of the O121 fliCH19 PCR. The combined use of O-antigen genotyping (O121 wzx) and the detection of O121 fliCH19 allele type contributes to improving the identification and molecular serotyping of EHEC O121:H19 motile and nonmotile strains and variants of these strains lacking stx genes. PMID:25862232

  14. Multidimensionally encoded magnetic resonance imaging.

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

  15. Virally encoded 7TM receptors

    Rosenkilde, M M; Waldhoer, M; Lüttichau, H R

    2001-01-01

    expression of this single gene in certain lymphocyte cell lineages leads to the development of lesions which are remarkably similar to Kaposi's sarcoma, a human herpesvirus 8 associated disease. Thus, this and other virally encoded 7TM receptors appear to be attractive future drug targets.......A number of herpes- and poxviruses encode 7TM G-protein coupled receptors most of which clearly are derived from their host chemokine system as well as induce high expression of certain 7TM receptors in the infected cells. The receptors appear to be exploited by the virus for either immune evasion...

  16. Calcium ferrite formation from the thermolysis of calcium tris (maleato)

    For preparing calcium ferrite, calcium tris (maleato) ferrate(III) precursor was prepared by mixing aqueous solutions of iron(III) maleate, calcium maleate and maleic acid. Various physico-chemical techniques i.e. TG, DTG, DTA, Mössbauer, XRD, IR etc have been used to study the decomposition behaviour from ambient to ...

  17. A sensor for calcium uptake

    Collins, Sean; Meyer, Tobias

    2011-01-01

    Mitochondria — the cell’s power plants — increase their energy production in response to calcium signals in the cytoplasm. A regulator of the elusive mitochondrial calcium channel has now been identified. PMID:20844529

  18. Children's Bone Health and Calcium

    ... Twitter Pinterest Email Print Children's Bone Health and Calcium: Condition Information What is bone health and how ... straight, walk, run, and lead an active life. Calcium is one of the key dietary building blocks ...

  19. Calcium – how and why?

    Unknown

    biological processes because of its unusual physical and chemical properties. 1. History of calcium ... cellular roles of calcium has established the importance of this ion ..... Ca2+ ion, for example in regulating enzyme activity (Price. 1975 ...

  20. Genetic basis of chronic pancreatitis

    Jansen, JBMJ; Morsche, RT; van Goor, Harry; Drenth, JPH

    2002-01-01

    Background: Pancreatitis has a proven genetic basis in a minority of patients. Methods: Review of the literature on genetics of pancreatitis. Results: Ever since the discovery that in most patients with hereditary pancreatitis a mutation in the gene encoding for cationic trypsinogen (R122H) was

  1. Solar Imagery - Chromosphere - Calcium

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset consists of full-disk images of the sun in Calcium (Ca) II K wavelength (393.4 nm). Ca II K imagery reveal magnetic structures of the sun from about 500...

  2. Antenatal calcium intake in Malaysia.

    Mahdy, Zaleha Abdullah; Basri, Hashimah; Md Isa, Zaleha; Ahmad, Shuhaila; Shamsuddin, Khadijah; Mohd Amin, Rahmah

    2014-04-01

    To determine the adequacy of antenatal calcium intake in Malaysia, and the influencing factors. A cross-sectional study was conducted among postnatal women who delivered in two tertiary hospitals. Data were collected from antenatal cards, hospital documents and diet recall on daily milk and calcium intake during pregnancy. SPSS version 19.0 was used for statistical analyses. A total of 150 women were studied. The total daily calcium intake was 834 ± 43 mg (mean ± standard error of the mean), but the calcium intake distribution curve was skewed to the right with a median intake of 725 mg daily. When calcium intake from milk and calcium supplements was excluded, the daily dietary calcium intake was only 478 ± 25 mg. Even with inclusion of milk and calcium supplements, more than a third (n=55 or 36.7%) of the women consumed less than 600 mg calcium in their daily diet. The adequacy of daily calcium intake was not influenced by maternal age, ethnicity, income or maternal job or educational status as well as parity. The daily dietary calcium intake of the Malaysian antenatal population is far from adequate without the addition of calcium supplements and milk. © 2013 The Authors. Journal of Obstetrics and Gynaecology Research © 2013 Japan Society of Obstetrics and Gynecology.

  3. The Plasma Membrane Calcium Pump

    Rasmussen, H.

    1983-01-01

    Three aspect of cellular calcium metabolism in animal cells was discussed including the importance of the plasma membrane in calcium homeostasis, experiments dealing with the actual mechanism of the calcium pump, and the function of the pump in relationship to the mitochondria and to the function of calmodulin in the intact cell.

  4. Genetically Engineered Cyanobacteria

    Zhou, Ruanbao (Inventor); Gibbons, William (Inventor)

    2015-01-01

    The disclosed embodiments provide cyanobacteria spp. that have been genetically engineered to have increased production of carbon-based products of interest. These genetically engineered hosts efficiently convert carbon dioxide and light into carbon-based products of interest such as long chained hydrocarbons. Several constructs containing polynucleotides encoding enzymes active in the metabolic pathways of cyanobacteria are disclosed. In many instances, the cyanobacteria strains have been further genetically modified to optimize production of the carbon-based products of interest. The optimization includes both up-regulation and down-regulation of particular genes.

  5. Calcium and bone health in children: a review.

    Stallings, V A

    1997-01-01

    The recent national survey shows that dietary calcium intake is variable in children and adolescents, with about half consuming less than the intake recommended by the Recommended Dietary Allowances or the National Institutes of Health Consensus Panel on Optimal Calcium Intake. Osteoporosis is a major disease in adults, resulting in 1.5 million fractures and over $10 billion in medical expenditures annually. Osteoporosis is of growing interest in the research, public health, and health consumer-lay communities and to the many primary care and specialty physicians and other health care professionals who work directly with patients with osteoporosis. Treatment of osteoporosis to prevent fracture is improving with newly introduced medications and approaches, but it is not as effective as needed. Effective prevention strategies are critical to decreasing the morbidity and mortality of the disease. Peak bone mass, obtained during childhood and adolescent growth, is one of the major determinants for the risk of developing osteoporosis and fracture. Genetic potential, gender, ethnic origins, nutritional factors such as calcium and vitamin D intake, growth patterns, and physical activity influence the accretion of bone mineral during childhood and determine the peak bone mass. Randomized, placebo-controlled intervention trials conducted in healthy children who are consuming amounts of dietary calcium in accordance with the US recommendations show that bone mass can be increased by calcium supplementation. Retrospective studies in adults suggest that childhood calcium intake is associated with risk of later osteoporosis and fracture. In addition, common childhood clinical conditions, such as low calcium intake related to lactose intolerance or the use of glucocorticoid medications for chronic illness, are risk factors for the development of osteoporosis in childhood, not just in adulthood. An approach for physicians and other pediatric care providers for screening children

  6. Encoding information into precipitation structures

    Martens, Kirsten; Bena, Ioana; Droz, Michel; Rácz, Zoltan

    2008-01-01

    Material design at submicron scales would be profoundly affected if the formation of precipitation patterns could be easily controlled. It would allow the direct building of bulk structures, in contrast to traditional techniques which consist of removing material in order to create patterns. Here, we discuss an extension of our recent proposal of using electrical currents to control precipitation bands which emerge in the wake of reaction fronts in A + + B – → C reaction–diffusion processes. Our main result, based on simulating the reaction–diffusion–precipitation equations, is that the dynamics of the charged agents can be guided by an appropriately designed time-dependent electric current so that, in addition to the control of the band spacing, the width of the precipitation bands can also be tuned. This makes straightforward the encoding of information into precipitation patterns and, as an amusing example, we demonstrate the feasibility by showing how to encode a musical rhythm

  7. Genome-wide analysis of wheat calcium ATPases and potential role of selected ACAs and ECAs in calcium stress.

    Aslam, Roohi; Williams, Lorraine E; Bhatti, Muhammad Faraz; Virk, Nasar

    2017-10-27

    P 2 - type calcium ATPases (ACAs-auto inhibited calcium ATPases and ECAs-endoplasmic reticulum calcium ATPases) belong to the P- type ATPase family of active membrane transporters and are significantly involved in maintaining accurate levels of Ca 2+ , Mn 2+ and Zn 2+ in the cytosol as well as playing a very important role in stress signaling, stomatal opening and closing and pollen tube growth. Here we report the identification and possible role of some of these ATPases from wheat. In this study, ACA and ECA sequences of six species (belonging to Poaceae) were retrieved from different databases and a phylogenetic tree was constructed. A high degree of evolutionary relatedness was observed among P 2 sequences characterized in this study. Members of the respective groups from different plant species were observed to fall under the same clade. This pattern highlights the common ancestry of P 2- type calcium ATPases. Furthermore, qRT-PCR was used to analyse the expression of selected ACAs and ECAs from Triticum aestivum (wheat) under calcium toxicity and calcium deficiency. The data indicated that expression of ECAs is enhanced under calcium stress, suggesting possible roles of these ATPases in calcium homeostasis in wheat. Similarly, the expression of ACAs was significantly different in plants grown under calcium stress as compared to plants grown under control conditions. This gives clues to the role of ACAs in signal transduction during calcium stress in wheat. Here we concluded that wheat genome consists of nine P 2B and three P 2A -type calcium ATPases. Moreover, gene loss events in wheat ancestors lead to the loss of a particular homoeolog of a gene in wheat. To elaborate the role of these wheat ATPases, qRT-PCR was performed. The results indicated that when plants are exposed to calcium stress, both P 2A and P 2B gene expression get enhanced. This further gives clues about the possible role of these ATPases in wheat in calcium management. These findings can be

  8. The mechanical environment modulates intracellular calcium oscillation activities of myofibroblasts.

    Charles Godbout

    Full Text Available Myofibroblast contraction is fundamental in the excessive tissue remodeling that is characteristic of fibrotic tissue contractures. Tissue remodeling during development of fibrosis leads to gradually increasing stiffness of the extracellular matrix. We propose that this increased stiffness positively feeds back on the contractile activities of myofibroblasts. We have previously shown that cycles of contraction directly correlate with periodic intracellular calcium oscillations in cultured myofibroblasts. We analyze cytosolic calcium dynamics using fluorescent calcium indicators to evaluate the possible impact of mechanical stress on myofibroblast contractile activity. To modulate extracellular mechanics, we seeded primary rat subcutaneous myofibroblasts on silicone substrates and into collagen gels of different elastic modulus. We modulated cell stress by cell growth on differently adhesive culture substrates, by restricting cell spreading area on micro-printed adhesive islands, and depolymerizing actin with Cytochalasin D. In general, calcium oscillation frequencies in myofibroblasts increased with increasing mechanical challenge. These results provide new insight on how changing mechanical conditions for myofibroblasts are encoded in calcium oscillations and possibly explain how reparative cells adapt their contractile behavior to the stresses occurring in normal and pathological tissue repair.

  9. CBL-CIPK network for calcium signaling in higher plants

    Luan, Sheng

    Plants sense their environment by signaling mechanisms involving calcium. Calcium signals are encoded by a complex set of parameters and decoded by a large number of proteins including the more recently discovered CBL-CIPK network. The calcium-binding CBL proteins specifi-cally interact with a family of protein kinases CIPKs and regulate the activity and subcellular localization of these kinases, leading to the modification of kinase substrates. This represents a paradigm shift as compared to a calcium signaling mechanism from yeast and animals. One example of CBL-CIPK signaling pathways is the low-potassium response of Arabidopsis roots. When grown in low-K medium, plants develop stronger K-uptake capacity adapting to the low-K condition. Recent studies show that the increased K-uptake is caused by activation of a specific K-channel by the CBL-CIPK network. A working model for this regulatory pathway will be discussed in the context of calcium coding and decoding processes.

  10. Transcriptome wide identification and validation of calcium sensor gene family in the developing spikes of finger millet genotypes for elucidating its role in grain calcium accumulation.

    Uma M Singh

    Full Text Available BACKGROUND: In finger millet, calcium is one of the important and abundant mineral elements. The molecular mechanisms involved in calcium accumulation in plants remains poorly understood. Transcriptome sequencing of genetically diverse genotypes of finger millet differing in grain calcium content will help in understanding the trait. PRINCIPAL FINDING: In this study, the transcriptome sequencing of spike tissues of two genotypes of finger millet differing in their grain calcium content, were performed for the first time. Out of 109,218 contigs, 78 contigs in case of GP-1 (Low Ca genotype and out of 120,130 contigs 76 contigs in case of GP-45 (High Ca genotype, were identified as calcium sensor genes. Through in silico analysis all 82 unique calcium sensor genes were classified into eight calcium sensor gene family viz., CaM & CaMLs, CBLs, CIPKs, CRKs, PEPRKs, CDPKs, CaMKs and CCaMK. Out of 82 genes, 12 were found diverse from the rice orthologs. The differential expression analysis on the basis of FPKM value resulted in 24 genes highly expressed in GP-45 and 11 genes highly expressed in GP-1. Ten of the 35 differentially expressed genes could be assigned to three documented pathways involved mainly in stress responses. Furthermore, validation of selected calcium sensor responder genes was also performed by qPCR, in developing spikes of both genotypes grown on different concentration of exogenous calcium. CONCLUSION: Through de novo transcriptome data assembly and analysis, we reported the comprehensive identification and functional characterization of calcium sensor gene family. The calcium sensor gene family identified and characterized in this study will facilitate in understanding the molecular basis of calcium accumulation and development of calcium biofortified crops. Moreover, this study also supported that identification and characterization of gene family through Illumina paired-end sequencing is a potential tool for generating the

  11. Transcriptome wide identification and validation of calcium sensor gene family in the developing spikes of finger millet genotypes for elucidating its role in grain calcium accumulation.

    Singh, Uma M; Chandra, Muktesh; Shankhdhar, Shailesh C; Kumar, Anil

    2014-01-01

    In finger millet, calcium is one of the important and abundant mineral elements. The molecular mechanisms involved in calcium accumulation in plants remains poorly understood. Transcriptome sequencing of genetically diverse genotypes of finger millet differing in grain calcium content will help in understanding the trait. In this study, the transcriptome sequencing of spike tissues of two genotypes of finger millet differing in their grain calcium content, were performed for the first time. Out of 109,218 contigs, 78 contigs in case of GP-1 (Low Ca genotype) and out of 120,130 contigs 76 contigs in case of GP-45 (High Ca genotype), were identified as calcium sensor genes. Through in silico analysis all 82 unique calcium sensor genes were classified into eight calcium sensor gene family viz., CaM & CaMLs, CBLs, CIPKs, CRKs, PEPRKs, CDPKs, CaMKs and CCaMK. Out of 82 genes, 12 were found diverse from the rice orthologs. The differential expression analysis on the basis of FPKM value resulted in 24 genes highly expressed in GP-45 and 11 genes highly expressed in GP-1. Ten of the 35 differentially expressed genes could be assigned to three documented pathways involved mainly in stress responses. Furthermore, validation of selected calcium sensor responder genes was also performed by qPCR, in developing spikes of both genotypes grown on different concentration of exogenous calcium. Through de novo transcriptome data assembly and analysis, we reported the comprehensive identification and functional characterization of calcium sensor gene family. The calcium sensor gene family identified and characterized in this study will facilitate in understanding the molecular basis of calcium accumulation and development of calcium biofortified crops. Moreover, this study also supported that identification and characterization of gene family through Illumina paired-end sequencing is a potential tool for generating the genomic information of gene family in non-model species.

  12. Transcriptome Wide Identification and Validation of Calcium Sensor Gene Family in the Developing Spikes of Finger Millet Genotypes for Elucidating Its Role in Grain Calcium Accumulation

    Singh, Uma M.; Chandra, Muktesh; Shankhdhar, Shailesh C.; Kumar, Anil

    2014-01-01

    Background In finger millet, calcium is one of the important and abundant mineral elements. The molecular mechanisms involved in calcium accumulation in plants remains poorly understood. Transcriptome sequencing of genetically diverse genotypes of finger millet differing in grain calcium content will help in understanding the trait. Principal Finding In this study, the transcriptome sequencing of spike tissues of two genotypes of finger millet differing in their grain calcium content, were performed for the first time. Out of 109,218 contigs, 78 contigs in case of GP-1 (Low Ca genotype) and out of 120,130 contigs 76 contigs in case of GP-45 (High Ca genotype), were identified as calcium sensor genes. Through in silico analysis all 82 unique calcium sensor genes were classified into eight calcium sensor gene family viz., CaM & CaMLs, CBLs, CIPKs, CRKs, PEPRKs, CDPKs, CaMKs and CCaMK. Out of 82 genes, 12 were found diverse from the rice orthologs. The differential expression analysis on the basis of FPKM value resulted in 24 genes highly expressed in GP-45 and 11 genes highly expressed in GP-1. Ten of the 35 differentially expressed genes could be assigned to three documented pathways involved mainly in stress responses. Furthermore, validation of selected calcium sensor responder genes was also performed by qPCR, in developing spikes of both genotypes grown on different concentration of exogenous calcium. Conclusion Through de novo transcriptome data assembly and analysis, we reported the comprehensive identification and functional characterization of calcium sensor gene family. The calcium sensor gene family identified and characterized in this study will facilitate in understanding the molecular basis of calcium accumulation and development of calcium biofortified crops. Moreover, this study also supported that identification and characterization of gene family through Illumina paired-end sequencing is a potential tool for generating the genomic information of

  13. Calcium, essential for health

    Martínez de Victoria, Emilio

    2016-07-12

    Calcium (Ca) is the most abundant mineral element in our body. It accounts for about 2% of body weight. The functions of calcium are: a) functions skeletal and b) regulatory functions. Bone consists of a protein matrix that mineralizes mainly with calcium (the most abundant), phosphate and magnesium, for it is essential an adequate dietary intake of Ca, phosphorus and vitamin D. The ionic Ca (Ca2+) is essential to maintain and / or perform different specialized functions of, virtually, all body cells cellular. Because of its important functions Ca2+ must be closely regulated, keeping plasma concentrations within narrow ranges. For this reason there is an accurate response against hypocalcemia or hypercalcemia in which the parathormone, calcitriol, calcitonin and vitamin K are involved. Ca intakes in the Spanish population are low in a significant percentage of the older adult’s population, especially in women. The main source of Ca in the diet is milk and milk derivatives. Green leafy vegetables, fruits and legumes can be important sources of Ca in a Mediterranean dietary pattern. The bioavailability of dietary Ca depends on physiological and dietary factors. Physiological include age, physiological status (gestation and lactation) Ca and vitamin D status and disease. Several studies relate Ca intake in the diet and various diseases, such as osteoporosis, cancer, cardiovascular disease and obesity.

  14. Models of calcium signalling

    Dupont, Geneviève; Kirk, Vivien; Sneyd, James

    2016-01-01

    This book discusses the ways in which mathematical, computational, and modelling methods can be used to help understand the dynamics of intracellular calcium. The concentration of free intracellular calcium is vital for controlling a wide range of cellular processes, and is thus of great physiological importance. However, because of the complex ways in which the calcium concentration varies, it is also of great mathematical interest.This book presents the general modelling theory as well as a large number of specific case examples, to show how mathematical modelling can interact with experimental approaches, in an interdisciplinary and multifaceted approach to the study of an important physiological control mechanism. Geneviève Dupont is FNRS Research Director at the Unit of Theoretical Chronobiology of the Université Libre de Bruxelles;Martin Falcke is head of the Mathematical Cell Physiology group at the Max Delbrück Center for Molecular Medicine, Berlin;Vivien Kirk is an Associate Professor in the Depar...

  15. Determination of percent calcium carbonate in calcium chromate

    Middleton, H.W.

    1979-01-01

    The precision, accuracy and reliability of the macro-combustion method is superior to the Knorr alkalimetric method, and it is faster. It also significantly reduces the calcium chromate waste accrual problem. The macro-combustion method has been adopted as the official method for determination of percent calcium carbonate in thermal battery grade anhydrous calcium chromate and percent calcium carbonate in quicklime used in the production of calcium chromate. The apparatus and procedure can be used to measure the percent carbonate in inorganic materials other than calcium chromate. With simple modifications in the basic apparatus and procedure, the percent carbon and hydrogen can be measured in many organic material, including polymers and polymeric formulations. 5 figures, 5 tables

  16. Calcium oxalate stone and gout.

    Marickar, Y M Fazil

    2009-12-01

    Gout is well known to be produced by increased uric acid level in blood. The objective of this paper is to assess the relationship between gout and calcium oxalate stone formation in the humans. 48 patients with combination of gout and calcium oxalate stone problem were included. The biochemical values of this group were compared with 38 randomly selected uric acid stone patients with gout, 43 stone patients with gout alone, 100 calcium oxalate stone patients without gout and 30 controls, making a total of 259 patients. Various biochemical parameters, namely serum calcium, phosphorus and uric acid and 24-h urine calcium, phosphorus, uric acid, oxalate, citrate and magnesium were analysed. ANOVA and Duncan's multiple-range tests were performed to assess statistical significance of the variations. The promoters of stone formation, namely serum calcium (P stone patients and gouty calcium oxalate stone patients compared to the non-gouty patients and controls. Urine oxalate (P stones patients. The inhibitor urine citrate (P stone gouty patients, followed by the gouty uric acid stone formers and gouty calcium oxalate stone patients. The high values of promoters, namely uric acid and calcium in the gouty stone patients indicate the tendency for urinary stone formation in the gouty stone patients. There is probably a correlation between gout and calcium oxalate urinary stone. We presume this mechanism is achieved through the uric acid metabolism. The findings point to the summation effect of metabolic changes in development of stone disease.

  17. Calcium Signaling in Taste Cells

    Medler, Kathryn F.

    2014-01-01

    The sense of taste is a common ability shared by all organisms and is used to detect nutrients as well as potentially harmful compounds. Thus taste is critical to survival. Despite its importance, surprisingly little is known about the mechanisms generating and regulating responses to taste stimuli. All taste responses depend on calcium signals to generate appropriate responses which are relayed to the brain. Some taste cells have conventional synapses and rely on calcium influx through voltage-gated calcium channels. Other taste cells lack these synapses and depend on calcium release to formulate an output signal through a hemichannel. Beyond establishing these characteristics, few studies have focused on understanding how these calcium signals are formed. We identified multiple calcium clearance mechanisms that regulate calcium levels in taste cells as well as a calcium influx that contributes to maintaining appropriate calcium homeostasis in these cells. Multiple factors regulate the evoked taste signals with varying roles in different cell populations. Clearly, calcium signaling is a dynamic process in taste cells and is more complex than has previously been appreciated. PMID:25450977

  18. A deep auto-encoder model for gene expression prediction.

    Xie, Rui; Wen, Jia; Quitadamo, Andrew; Cheng, Jianlin; Shi, Xinghua

    2017-11-17

    Gene expression is a key intermediate level that genotypes lead to a particular trait. Gene expression is affected by various factors including genotypes of genetic variants. With an aim of delineating the genetic impact on gene expression, we build a deep auto-encoder model to assess how good genetic variants will contribute to gene expression changes. This new deep learning model is a regression-based predictive model based on the MultiLayer Perceptron and Stacked Denoising Auto-encoder (MLP-SAE). The model is trained using a stacked denoising auto-encoder for feature selection and a multilayer perceptron framework for backpropagation. We further improve the model by introducing dropout to prevent overfitting and improve performance. To demonstrate the usage of this model, we apply MLP-SAE to a real genomic datasets with genotypes and gene expression profiles measured in yeast. Our results show that the MLP-SAE model with dropout outperforms other models including Lasso, Random Forests and the MLP-SAE model without dropout. Using the MLP-SAE model with dropout, we show that gene expression quantifications predicted by the model solely based on genotypes, align well with true gene expression patterns. We provide a deep auto-encoder model for predicting gene expression from SNP genotypes. This study demonstrates that deep learning is appropriate for tackling another genomic problem, i.e., building predictive models to understand genotypes' contribution to gene expression. With the emerging availability of richer genomic data, we anticipate that deep learning models play a bigger role in modeling and interpreting genomics.

  19. Hall effect encoding of brushless dc motors

    Berard, C. A.; Furia, T. J.; Goldberg, E. A.; Greene, R. C.

    1970-01-01

    Encoding mechanism integral to the motor and using the permanent magnets embedded in the rotor eliminates the need for external devices to encode information relating the position and velocity of the rotating member.

  20. Characterization of calcium oxalate biominerals in Pereskia species (Cactaceae).

    Monje, Paula V; Baran, Enrique J

    2009-01-01

    Calcium oxalate druses were isolated from the stems and leaves of six Pereskioideae family members and investigated by infrared spectroscopy, showing that in all samples the biomineral was present in the form of whewellite, CaC2O4 x H2O. As Pereskia is thought to represent the "ancestral" condition of the leafless stem-succulent cacti, these results suggest that the biomineralization of calcium oxalate in Cactaceae represents a primitive characteristic of the group and also support a close genetic relationship between Pereskia and Opuntia.

  1. Flipped-Adversarial AutoEncoders

    Zhang, Jiyi; Dang, Hung; Lee, Hwee Kuan; Chang, Ee-Chien

    2018-01-01

    We propose a flipped-Adversarial AutoEncoder (FAAE) that simultaneously trains a generative model G that maps an arbitrary latent code distribution to a data distribution and an encoder E that embodies an "inverse mapping" that encodes a data sample into a latent code vector. Unlike previous hybrid approaches that leverage adversarial training criterion in constructing autoencoders, FAAE minimizes re-encoding errors in the latent space and exploits adversarial criterion in the data space. Exp...

  2. Cardiovascular Effects of Calcium Supplements

    Ian R. Reid

    2013-07-01

    Full Text Available Calcium supplements reduce bone turnover and slow the rate of bone loss. However, few studies have demonstrated reduced fracture incidence with calcium supplements, and meta-analyses show only a 10% decrease in fractures, which is of borderline statistical and clinical significance. Trials in normal older women and in patients with renal impairment suggest that calcium supplements increase the risk of cardiovascular disease. To further assess their safety, we recently conducted a meta-analysis of trials of calcium supplements, and found a 27%–31% increase in risk of myocardial infarction, and a 12%–20% increase in risk of stroke. These findings are robust because they are based on pre-specified analyses of randomized, placebo-controlled trials and are consistent across the trials. Co-administration of vitamin D with calcium does not lessen these adverse effects. The increased cardiovascular risk with calcium supplements is consistent with epidemiological data relating higher circulating calcium concentrations to cardiovascular disease in normal populations. There are several possible pathophysiological mechanisms for these effects, including effects on vascular calcification, vascular cells, blood coagulation and calcium-sensing receptors. Thus, the non-skeletal risks of calcium supplements appear to outweigh any skeletal benefits, and are they appear to be unnecessary for the efficacy of other osteoporosis treatments.

  3. SR calcium handling and calcium after-transients in a rabbit model of heart failure

    Baartscheer, Antonius; Schumacher, Cees A.; Belterman, Charly N. W.; Coronel, Ruben; Fiolet, Jan W. T.

    2003-01-01

    Objective: After-depolarization associated arrhythmias are frequently observed in heart failure and associated with spontaneous calcium release from sarcoplasmic reticulum (SR), calcium after-transients. We hypothesize that disturbed SR calcium handling underlies calcium after-transients in heart

  4. Optimization of a GCaMP calcium indicator for neural activity imaging.

    Akerboom, Jasper; Chen, Tsai-Wen; Wardill, Trevor J; Tian, Lin; Marvin, Jonathan S; Mutlu, Sevinç; Calderón, Nicole Carreras; Esposti, Federico; Borghuis, Bart G; Sun, Xiaonan Richard; Gordus, Andrew; Orger, Michael B; Portugues, Ruben; Engert, Florian; Macklin, John J; Filosa, Alessandro; Aggarwal, Aman; Kerr, Rex A; Takagi, Ryousuke; Kracun, Sebastian; Shigetomi, Eiji; Khakh, Baljit S; Baier, Herwig; Lagnado, Leon; Wang, Samuel S-H; Bargmann, Cornelia I; Kimmel, Bruce E; Jayaraman, Vivek; Svoboda, Karel; Kim, Douglas S; Schreiter, Eric R; Looger, Loren L

    2012-10-03

    Genetically encoded calcium indicators (GECIs) are powerful tools for systems neuroscience. Recent efforts in protein engineering have significantly increased the performance of GECIs. The state-of-the art single-wavelength GECI, GCaMP3, has been deployed in a number of model organisms and can reliably detect three or more action potentials in short bursts in several systems in vivo. Through protein structure determination, targeted mutagenesis, high-throughput screening, and a battery of in vitro assays, we have increased the dynamic range of GCaMP3 by severalfold, creating a family of "GCaMP5" sensors. We tested GCaMP5s in several systems: cultured neurons and astrocytes, mouse retina, and in vivo in Caenorhabditis chemosensory neurons, Drosophila larval neuromuscular junction and adult antennal lobe, zebrafish retina and tectum, and mouse visual cortex. Signal-to-noise ratio was improved by at least 2- to 3-fold. In the visual cortex, two GCaMP5 variants detected twice as many visual stimulus-responsive cells as GCaMP3. By combining in vivo imaging with electrophysiology we show that GCaMP5 fluorescence provides a more reliable measure of neuronal activity than its predecessor GCaMP3. GCaMP5 allows more sensitive detection of neural activity in vivo and may find widespread applications for cellular imaging in general.

  5. 21 CFR 573.240 - Calcium periodate.

    2010-04-01

    ... with calcium hydroxide or calcium oxide to form a substance consisting of not less than 60 percent by... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium periodate. 573.240 Section 573.240 Food... Additive Listing § 573.240 Calcium periodate. The food additive calcium periodate may be safely used in...

  6. 21 CFR 573.260 - Calcium silicate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium silicate. 573.260 Section 573.260 Food and... Listing § 573.260 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely used as an anticaking agent in animal feed, provided that the amount of calcium silicate does not...

  7. Expression analysis of a ''Cucurbita'' cDNA encoding endonuclease

    Szopa, J.

    1995-01-01

    The nuclear matrices of plant cell nuclei display intrinsic nuclease activity which consists in nicking supercoiled DNA. A cDNA encoding a 32 kDa endonuclease has been cloned and sequenced. The nucleotide and deduced amino-acid sequences show high homology to known 14-3-3-protein sequences from other sources. The amino-acid sequence shows agreement with consensus sequences for potential phosphorylation by protein kinase A and C and for calcium, lipid and membrane-binding sites. The nucleotide-binding site is also present within the conserved part of the sequence. By Northern blot analysis, the differential expression of the corresponding mRNA was detected; it was the strongest in sink tissues. The endonuclease activity found on DNA-polyacrylamide gel electrophoresis coincided with mRNA content and was the highest in tuber. (author). 22 refs, 6 figs

  8. 21 CFR 172.330 - Calcium pantothenate, calcium chloride double salt.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium pantothenate, calcium chloride double salt... FOOD FOR HUMAN CONSUMPTION Special Dietary and Nutritional Additives § 172.330 Calcium pantothenate, calcium chloride double salt. The food additive calcium chloride double salt of calcium pantothenate may...

  9. The Effects of Dietary Calcium and/or Iron Deficiency upon Murine Intestinal Calcium Binding Protein Activity and Calcium Absorption

    McDonald, Catherine M.

    1980-01-01

    Iron deficiency has been shown to impair calcium absorption, leading to decreased bone mass. Vitamin D3-dependent calcium binding protein (CaBP) has been demonstrated to be necessary for the active transport of calcium in the intestine of numerous species. Iron deficiency might affect the activity of the calcium binding protein. Four experimental diets were formulated as follows: Diet 1, iron adequate, calcium adequate; Diet 2, iron deficient, calcium adequate; Diet 3, iron adequate, calci...

  10. Amplifying genetic logic gates.

    Bonnet, Jerome; Yin, Peter; Ortiz, Monica E; Subsoontorn, Pakpoom; Endy, Drew

    2013-05-03

    Organisms must process information encoded via developmental and environmental signals to survive and reproduce. Researchers have also engineered synthetic genetic logic to realize simpler, independent control of biological processes. We developed a three-terminal device architecture, termed the transcriptor, that uses bacteriophage serine integrases to control the flow of RNA polymerase along DNA. Integrase-mediated inversion or deletion of DNA encoding transcription terminators or a promoter modulates transcription rates. We realized permanent amplifying AND, NAND, OR, XOR, NOR, and XNOR gates actuated across common control signal ranges and sequential logic supporting autonomous cell-cell communication of DNA encoding distinct logic-gate states. The single-layer digital logic architecture developed here enables engineering of amplifying logic gates to control transcription rates within and across diverse organisms.

  11. Calcium, vitamin D, and your bones

    ... page: //medlineplus.gov/ency/patientinstructions/000490.htm Calcium, vitamin D, and your bones To use the sharing ... and maintain strong bones. How Much Calcium and Vitamin D do I Need? Amounts of calcium are ...

  12. Calcium Supplements: Do Men Need Them Too?

    ... Lifestyle Nutrition and healthy eating Should men take calcium supplements? Answers from Katherine Zeratsky, R.D., L. ... Most healthy men don't need to take calcium supplements. Calcium is important for men for optimal ...

  13. Calcium transport in turtle bladder

    Sabatini, S.; Kurtzman, N.A.

    1987-01-01

    Unidirectional 45 Ca fluxes were measured in the turtle bladder under open-circuit and short-circuit conditions. In the open-circuited state net calcium flux (J net Ca ) was secretory (serosa to mucosa). Ouabain reversed J net Ca to an absorptive flux. Amiloride reduced both fluxes such that J net Ca was not significantly different from zero. Removal of mucosal sodium caused net calcium absorption; removal of serosal sodium caused calcium secretion. When bladders were short circuited, J net Ca decreased to approximately one-third of control value but remained secretory. When ouabain was added under short-circuit conditions, J net Ca was similar in magnitude and direction to ouabain under open-circuited conditions (i.e., absorptive). Tissue 45 Ca content was ≅30-fold lower when the isotope was placed in the mucosal bath, suggesting that the apical membrane is the resistance barrier to calcium transport. The results obtained in this study are best explained by postulating a Ca 2+ -ATPase on the serosa of the turtle bladder epithelium and a sodium-calcium antiporter on the mucosa. In this model, the energy for calcium movement would be supplied, in large part, by the Na + -K + -ATPase. By increasing cell sodium, ouabain would decrease the activity of the mucosal sodium-calcium exchanger (or reverse it), uncovering active calcium transport across the serosa

  14. Calcium chromate process related investigations

    Dillard, B.M.

    1979-01-01

    A pilot plant for production of calcium chromate has been scaled up to a small production facility at the General Electric Neutron Devices Department. In preparation for this scale-up, the process and final product were studied in order to evaluate problems not considered previously. The variables and processes studied included: (1) the determination of optimum drying temperature and time for product analysis; (2) the effect of the grade of lime used as the precipitating agent on the purity of the calcium chromate; (3) product purity when calcium chromate is precipitated by the addition of ammonium chromate to slaked lime; (4) the reagents best suited for cleaning calcium chromate spills; and (5) methods for determining hydroxide ion concentration in calcium chromate. The optimum drying time for the product before analysis is four hours at 600 0 C. Gases evolved at various temperatures during the drying process were carbon dioxide and water vapor. Technical grade lime produced calcium chromate of the highest purity. Both nitric and acetic acids were efficient dissolvers of calcium chromate spills. Direct titration of hydroxide ion with sulfuric acid gave an average recovery of 93% for samples spiked with calcium hydroxide. 1 figure, 17 tables

  15. Genetic architecture of wild soybean (Glycine soja) response to soybean cyst nematode (Heterodera glycines).

    Zhang, Hengyou; Song, Qijian; Griffin, Joshua D; Song, Bao-Hua

    2017-12-01

    The soybean cyst nematode (SCN) is one of the most destructive pathogens of soybean plants worldwide. Host-plant resistance is an environmentally friendly method to mitigate SCN damage. To date, the resistant soybean cultivars harbor limited genetic variation, and some are losing resistance. Thus, a better understanding of the genetic mechanisms of the SCN resistance, as well as developing diverse resistant soybean cultivars, is urgently needed. In this study, a genome-wide association study (GWAS) was conducted using 1032 wild soybean (Glycine soja) accessions with over 42,000 single-nucleotide polymorphisms (SNPs) to understand the genetic architecture of G. soja resistance to SCN race 1. Ten SNPs were significantly associated with the response to race 1. Three SNPs on chromosome 18 were localized within the previously identified quantitative trait loci (QTLs), and two of which were localized within a strong linkage disequilibrium block encompassing a nucleotide-binding (NB)-ARC disease resistance gene (Glyma.18G102600). Genes encoding methyltransferases, the calcium-dependent signaling protein, the leucine-rich repeat kinase family protein, and the NB-ARC disease resistance protein, were identified as promising candidate genes. The identified SNPs and candidate genes can not only shed light on the molecular mechanisms underlying SCN resistance, but also can facilitate soybean improvement employing wild genetic resources.

  16. Tagging, Encoding, and Jones Optimality

    Danvy, Olivier; Lopez, Pablo E. Martinez

    2003-01-01

    A partial evaluator is said to be Jones-optimal if the result of specializing a self-interpreter with respect to a source program is textually identical to the source program, modulo renaming. Jones optimality has already been obtained if the self-interpreter is untyped. If the selfinterpreter...... is typed, however, residual programs are cluttered with type tags. To obtain the original source program, these tags must be removed. A number of sophisticated solutions have already been proposed. We observe, however, that with a simple representation shift, ordinary partial evaluation is already Jones......-optimal, modulo an encoding. The representation shift amounts to reading the type tags as constructors for higherorder abstract syntax. We substantiate our observation by considering a typed self-interpreter whose input syntax is higher-order. Specializing this interpreter with respect to a source program yields...

  17. Calcium addition in straw gasification

    Risnes, H.; Fjellerup, Jan Søren; Henriksen, Ulrik Birk

    2003-01-01

    The present work focuses on the influence of calcium addition in gasification. The inorganic¿organic element interaction as well as the detailed inorganic¿inorganic elements interaction has been studied. The effect of calcium addition as calcium sugar/molasses solutions to straw significantly...... affected the ash chemistry and the ash sintering tendency but much less the char reactivity. Thermo balance test are made and high-temperature X-ray diffraction measurements are performed, the experimental results indicate that with calcium addition major inorganic¿inorganic reactions take place very late...... in the char conversion process. Comprehensive global equilibrium calculations predicted important characteristics of the inorganic ash residue. Equilibrium calculations predict the formation of liquid salt if sufficient amounts of Ca are added and according to experiments as well as calculations calcium binds...

  18. Emotional arousal and memory after deep encoding.

    Leventon, Jacqueline S; Camacho, Gabriela L; Ramos Rojas, Maria D; Ruedas, Angelica

    2018-05-22

    Emotion often enhances long-term memory. One mechanism for this enhancement is heightened arousal during encoding. However, reducing arousal, via emotion regulation (ER) instructions, has not been associated with reduced memory. In fact, the opposite pattern has been observed: stronger memory for emotional stimuli encoded with an ER instruction to reduce arousal. This pattern may be due to deeper encoding required by ER instructions. In the current research, we examine the effects of emotional arousal and deep-encoding on memory across three studies. In Study 1, adult participants completed a writing task (deep-encoding) for encoding negative, neutral, and positive picture stimuli, whereby half the emotion stimuli had the ER instruction to reduce the emotion. Memory was strong across conditions, and no memory enhancement was observed for any condition. In Study 2, adult participants completed the same writing task as Study 1, as well as a shallow-encoding task for one-third of negative, neutral, and positive trials. Memory was strongest for deep vs. shallow encoding trials, with no effects of emotion or ER instruction. In Study 3, adult participants completed a shallow-encoding task for negative, neutral, and positive stimuli, with findings indicating enhanced memory for negative emotional stimuli. Findings suggest that deep encoding must be acknowledged as a source of memory enhancement when examining manipulations of emotion-related arousal. Copyright © 2018. Published by Elsevier B.V.

  19. Evolution of the Calcium Paradigm: The Relation between Vitamin D, Serum Calcium and Calcium Absorption

    Borje E. Christopher Nordin

    2010-09-01

    Full Text Available Osteoporosis is the index disease for calcium deficiency, just as rickets/osteomalacia is the index disease for vitamin D deficiency, but there is considerable overlap between them. The common explanation for this overlap is that hypovitaminosis D causes malabsorption of calcium which then causes secondary hyperparathyroidism and is effectively the same thing as calcium deficiency. This paradigm is incorrect. Hypovitaminosis D causes secondary hyperparathyroidism at serum calcidiol levels lower than 60 nmol/L long before it causes malabsorption of calcium because serum calcitriol (which controls calcium absorption is maintained until serum calcidiol falls below 20 nmol/L. This secondary hyperparathyroidism, probably due to loss of a “calcaemic” action of vitamin D on bone first described in 1957, destroys bone and explains why vitamin D insufficiency is a risk factor for osteoporosis. Vitamin D thus plays a central role in the maintenance of the serum (ionised calcium, which is more important to the organism than the preservation of the skeleton. Bone is sacrificed when absorbed dietary calcium does not match excretion through the skin, kidneys and bowel which is why calcium deficiency causes osteoporosis in experimental animals and, by implication, in humans.

  20. Automated Video-Based Analysis of Contractility and Calcium Flux in Human-Induced Pluripotent Stem Cell-Derived Cardiomyocytes Cultured over Different Spatial Scales.

    Huebsch, Nathaniel; Loskill, Peter; Mandegar, Mohammad A; Marks, Natalie C; Sheehan, Alice S; Ma, Zhen; Mathur, Anurag; Nguyen, Trieu N; Yoo, Jennie C; Judge, Luke M; Spencer, C Ian; Chukka, Anand C; Russell, Caitlin R; So, Po-Lin; Conklin, Bruce R; Healy, Kevin E

    2015-05-01

    Contractile motion is the simplest metric of cardiomyocyte health in vitro, but unbiased quantification is challenging. We describe a rapid automated method, requiring only standard video microscopy, to analyze the contractility of human-induced pluripotent stem cell-derived cardiomyocytes (iPS-CM). New algorithms for generating and filtering motion vectors combined with a newly developed isogenic iPSC line harboring genetically encoded calcium indicator, GCaMP6f, allow simultaneous user-independent measurement and analysis of the coupling between calcium flux and contractility. The relative performance of these algorithms, in terms of improving signal to noise, was tested. Applying these algorithms allowed analysis of contractility in iPS-CM cultured over multiple spatial scales from single cells to three-dimensional constructs. This open source software was validated with analysis of isoproterenol response in these cells, and can be applied in future studies comparing the drug responsiveness of iPS-CM cultured in different microenvironments in the context of tissue engineering.

  1. SnoVault and encodeD: A novel object-based storage system and applications to ENCODE metadata.

    Benjamin C Hitz

    Full Text Available The Encyclopedia of DNA elements (ENCODE project is an ongoing collaborative effort to create a comprehensive catalog of functional elements initiated shortly after the completion of the Human Genome Project. The current database exceeds 6500 experiments across more than 450 cell lines and tissues using a wide array of experimental techniques to study the chromatin structure, regulatory and transcriptional landscape of the H. sapiens and M. musculus genomes. All ENCODE experimental data, metadata, and associated computational analyses are submitted to the ENCODE Data Coordination Center (DCC for validation, tracking, storage, unified processing, and distribution to community resources and the scientific community. As the volume of data increases, the identification and organization of experimental details becomes increasingly intricate and demands careful curation. The ENCODE DCC has created a general purpose software system, known as SnoVault, that supports metadata and file submission, a database used for metadata storage, web pages for displaying the metadata and a robust API for querying the metadata. The software is fully open-source, code and installation instructions can be found at: http://github.com/ENCODE-DCC/snovault/ (for the generic database and http://github.com/ENCODE-DCC/encoded/ to store genomic data in the manner of ENCODE. The core database engine, SnoVault (which is completely independent of ENCODE, genomic data, or bioinformatic data has been released as a separate Python package.

  2. Encoder designed to work in harsh environments

    Toop, L.

    2007-05-15

    Dynapar has developed the Acuro AX71 absolute encoder for use on offshore or land-based oil rig operations. It provides feedback on the operation of automated systems such as draw works, racking systems, rotary tables and top drives. By ensuring that automated systems function properly, this encoder responds to a need by the oil and gas industry to keep workers safe and improve efficiency, particularly for operations in rugged situations. The encoder provides feedback from motor systems to controllers, giving information about position and speed of downhole drill bits. This newly developed encoder is better than commonly used incremental encoders which are not precise in strong electrical noise environments. Rather, the absolute encoder uses a different method of reporting to the controller. A digital signal is transmitted constantly as the device operates. It is less susceptible to noise issues. It is highly accurate, tolerant of noise and is not affected by power outages. However, the absolute encoder is generally more delicate in drilling applications with high ambient temperatures and shock levels. Dynapar addressed this issue by developing compact stainless steel housing that is useful for corrosion resistance in marine applications. The AX71 absolute encoder can withstand up to 100 G of mechanical shock and ambient temperatures of up to 60 degrees C. The encoder is ATEX certified without barriers, and offers the high resolution feedback of 4,000 counts of multiturn rotation and 16,000 counts of position. 1 fig.

  3. Calcium and Calcium Supplements: Achieving the Right Balance

    ... may have on heart attack risk. A similar controversy surrounds calcium and prostate cancer. Some studies have ... your agreement to the Terms and Conditions and Privacy Policy linked below. Terms and Conditions Privacy Policy ...

  4. Calcium signals in olfactory neurons.

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.

  5. Why Calcium? How Calcium Became the Best Communicator*

    Carafoli, Ernesto; Krebs, Joachim

    2016-01-01

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations,...

  6. Isomorfic Substitutions of Calcium by Strontium in Calcium Hydroxyapatite

    Christensen, Hilbert

    1962-12-01

    By means of homogeneous precipitation it has been possible to synthesize crystalline solid solutions of calcium strontium hydroxyapatite from aqueous solutions. The lattice constants for the solid solutions were measured in the range Ca 9 Sr(PO 4 ) 6 (OH) 2 - CaSr 9 (PO 4 ) 6 (OH) 2 . The investigations show that the discrimination of strontium against calcium is considerably smaller than reported elsewhere (1). Strontium is preferentially built into the c-axis direction of the apatite lattice

  7. Influence of dietary calcium on bone calcium utilization

    Farmer, M.; Roland, D.A. Sr.; Clark, A.J.

    1986-01-01

    In Experiment 1, 10 microCi 45 Ca/day were administered to 125 hens for 10 days. Hens were then allocated to five treatments with calcium levels ranging from .08 to 3.75% of the diet. In Experiment 2, hens with morning oviposition times were randomly allocated to 11 treatments that were periods of time postoviposition ranging from 6 hr to 24 hr, in 2-hr increments (Experiment 2). At the end of each 2-hr period, eggs from 25 hens were removed from the uterus. The 18-, 20-, and 22-hr treatments were replicated three times. In Experiment 3, hens were fed either ad libitum or feed was withheld the last 5 or 6 hr before oviposition. In Experiment 4, hens were fed 10 microCi of 45 Ca for 15 days to label skeletal calcium. Hens were divided into two groups and fed a .08 or 3.75% calcium diet for 2 days. On the second day, 25 hens fed the 3.75% calcium diet were intubated with 7 g of the same diet containing .5 g calcium at 1700, 2100, 0100, 0500, and 0700 hr. The measurements used were egg weight, shell weight, and 45 Ca content of the egg shell. Results indicated a significant linear or quadratic regression of dietary calcium levels on 45 Ca accumulation in eggshells and eggshell weight (Experiment 1). As the calcium level of the diet increased, eggshell weight increased and 45 Ca recovery decreased. Utilization of skeletal calcium for shell formation ranged from 28 to 96%. In Experiment 2, the rate of shell calcification was not constant throughout the calcification process but varied significantly

  8. Bacteriophages encode factors required for protection in a symbiotic mutualism.

    Oliver, Kerry M; Degnan, Patrick H; Hunter, Martha S; Moran, Nancy A

    2009-08-21

    Bacteriophages are known to carry key virulence factors for pathogenic bacteria, but their roles in symbiotic bacteria are less well understood. The heritable symbiont Hamiltonella defensa protects the aphid Acyrthosiphon pisum from attack by the parasitoid Aphidius ervi by killing developing wasp larvae. In a controlled genetic background, we show that a toxin-encoding bacteriophage is required to produce the protective phenotype. Phage loss occurs repeatedly in laboratory-held H. defensa-infected aphid clonal lines, resulting in increased susceptibility to parasitism in each instance. Our results show that these mobile genetic elements can endow a bacterial symbiont with benefits that extend to the animal host. Thus, phages vector ecologically important traits, such as defense against parasitoids, within and among symbiont and animal host lineages.

  9. 21 CFR 172.410 - Calcium silicate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium silicate. 172.410 Section 172.410 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Agents § 172.410 Calcium silicate. Calcium silicate, including synthetic calcium silicate, may be safely...

  10. A Crash Course in Calcium Channels.

    Zamponi, Gerald W

    2017-12-20

    Much progress has been made in understanding the molecular physiology and pharmacology of calcium channels. Recently, there have been tremendous advances in learning about calcium channel structure and function through crystallography and cryo-electron microscopy studies. Here, I will give an overview of our knowledge about calcium channels, and highlight two recent studies that give important insights into calcium channel structure.

  11. Calcium phosphates for biomedical applications

    Maria Canillas

    2017-05-01

    Full Text Available The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies.

  12. Functions of vitamin D / Calcium

    First page Back Continue Last page Overview Graphics. Excitation-contraction coupling,. Cardiac functions. Hormonal secretion. Control of enzymatic reactions. Mitotic division. Maintenance of cell integrity. Ciliary motility. Notes: Calcium is a vital second messenger.

  13. Calcium signals in planetary embryos

    Morbidelli, Alessandro

    2018-03-01

    The calcium-isotope composition of planetary bodies in the inner Solar System correlates with the masses of such objects. This finding could have implications for our understanding of how the Solar System formed.

  14. Calcium homeostasis in diabetes mellitus.

    Ahn, Changhwan; Kang, Ji-Houn; Jeung, Eui-Bae

    2017-09-30

    Diabetes mellitus (DM) is becoming a lifestyle-related pandemic disease. Diabetic patients frequently develop electrolyte disorders, especially diabetic ketoacidosis or nonketotic hyperglycemic hyperosmolar syndrome. Such patients show characteristic potassium, magnesium, phosphate, and calcium depletion. In this review, we discuss a homeostatic mechanism that links calcium and DM. We also provide a synthesis of the evidence in favor or against this linking mechanism by presenting recent clinical indications, mainly from veterinary research. There are consistent results supporting the use of calcium and vitamin D supplementation to reduce the risk of DM. Clinical trials support a marginal reduction in circulating lipids, and some meta-analyses support an increase in insulin sensitivity, following vitamin D supplementation. This review provides an overview of the calcium and vitamin D disturbances occurring in DM and describes the underlying mechanisms. Such elucidation will help indicate potential pathophysiology-based precautionary and therapeutic approaches and contribute to lowering the incidence of DM.

  15. Calcium phosphates for biomedical applications

    Canillas, M.; Pena, P.; Aza, A.H. de; Rodriguez, M.A.

    2017-07-01

    The history of calcium phosphates in the medicine field starts in 1769 when the first evidence of its existence in the bone tissue is discovered. Since then, the interest for calcium phosphates has increased among the scientific community. Their study has been developed in parallel with new advances in materials sciences, medicine or tissue engineering areas. Bone tissue engineering is the field where calcium phosphates have had a great importance. While the first bioceramics are selected according to bioinert, biocompatibility and mechanical properties with the aim to replace bone tissue damaged, calcium phosphates open the way to the bone tissue regeneration challenge. Nowadays, they are present in the majority of commercial products directed to repair or regenerate damaged bone tissue. Finally, in the last few decades, they have been suggested and studied as drug delivering devices and as vehicles of DNA and RNA for the future generation therapies. (Author)

  16. Learning Intelligent Genetic Algorithms Using Japanese Nonograms

    Tsai, Jinn-Tsong; Chou, Ping-Yi; Fang, Jia-Cen

    2012-01-01

    An intelligent genetic algorithm (IGA) is proposed to solve Japanese nonograms and is used as a method in a university course to learn evolutionary algorithms. The IGA combines the global exploration capabilities of a canonical genetic algorithm (CGA) with effective condensed encoding, improved fitness function, and modified crossover and…

  17. Journal of Genetics | Indian Academy of Sciences

    Home; Journals; Journal of Genetics. Chetana Sachidanandan. Articles written in Journal of Genetics. Volume 92 Issue 3 December 2013 pp 695-701 Perspectives. Time for the zebrafish ENCODE · Sridhar Sivasubbu Chetana Sachidanandan Vinod Scaria · More Details Fulltext PDF ...

  18. Effects of diphosphonate on kidney calcium content and duodenal absorption of 45calcium

    Goulding, A.; Cameron, V.

    1978-01-01

    In rats the relationships between EHDP-induced changes in serum calcium concentration, kidney calcium content and duodenal transport of 45 calcium were studied. Body weights and kidney weights were similar in all groups. EHDP administration was associated with an increase in serum calcium concentration and kidney calcium content, and a decrease in duodenal 45 calcium transport. In the EHDP-treated rats, there was a significant negative correlation between kidney calcium concentration and duodenal 45 calcium transport but no correlation between either kidney calcium content and serum calcium concentration (r = 0.116) or between serum calcium concentration and duodenal 45 calcium transport (r = 0.02). Further experiments will be needed to determine whether the demonstrated increase in kidney calcium content induced by EHDP administration was the cause of, or was secondary to, inhibition of 1, 25(OH) 2 D 3 synthesis. (orig./AJ) [de

  19. Research of calcium oxide hydration in calcium nitrate solutions

    M.A. Oliynyk

    2016-09-01

    Full Text Available Mineral fertilizers are one of the important factors of agriculture intensification and increasing of food products quantity. The volume of fertilizers production and its domestic consumption in Ukraine indicate that nitrogen fertilizer using only comes nearer to the required number of science-based. One of the most widespread artificial fertilizers is the calcium nitrate. Aim: The aim is to study and theoretically substantiate the processes occurring in the preparation of suspensions of calcium hydroxide Са(ОН2 in solution of calcium nitrate Ca(NО32. Materials and Methods: The technical calcium oxide (quicklime DSTU BV.2.7-90-99, solutions of calcium nitrate of 15, 20, 25, 30, 35 and 40% Ca(NО32 concentrations were used in the work. The content of lime in the preparation of a suspension in the solution changed (in terms of calcium oxide CaO from 150 g/dm3 to the maximum possible. Each of these solutions saturated at 40°С in lime to maximum concentration. Suitable for use in these experiments and in the technology of calcium nitrate obtaining are considered the solutions (suspensions that within 12 hours did not lose their mobility (transportability. Results: The experimental results show that increasing of the concentration of calcium nitrate in solution within the range 15...40%, the amount of lime that you can put into the solution without loss of transportability decreases. Further increasing of lime quantity in solutions concentrations causes to its solidifying, loss of mobility (transportability. Calculations showed that in the presence of calcium nitrate the solubility of Са(ОН2 is reduced nearly by order that can lead to the formation of calcium oxide CaO the solid phase Са(ОН2 on the surface, which also can form hydrogen bonds with the components of the solution. As the probability of formation of hydrogen bonds in solutions is high, there is a possibility of formation of clusters.

  20. Hulled and hull-less barley grains with the genetic trait for low-phytic acid increased the apparent total-tract digestibility of phosphorus and calcium in diets for young swine.

    Veum, T L; Raboy, V

    2016-03-01

    A 35-d experiment was conducted using 63 crossbred pigs (35 barrows and 28 gilts) with an initial average BW of 7.0 kg and age of 28 d to evaluate the efficacy of the low-phytic acid (LPA) genetic trait in hulled or hull-less barley in isocaloric diets. Hulled barleys were the normal barley (NB) cultivar Harrington and the near-isogenic LPA mutant 955 (M955) with P availabilities of 36 and 95%, respectively. Hull-less lines were produced by crossing NB and the LPA mutant 422 line with a hull-less line, producing hull-less NB (HNB) and hull-less mutant 422 (HM422) with P availabilities of 41 and 66%, respectively. Pigs were in individual metabolism cages or pens for Phase 1 (d 0 to 14) and Phase 2 (d 14 to 35). Diets defined as NB, HNB, HM422, or M955 with no added inorganic P (iP) had available P (aP) concentrations of 0.27, 0.28, 0.35, and 0.40% for Phase 1 and 0.15, 0.17, 0.23, and 0.31% for Phase 2, respectively. Only diet M955 was adequate in aP. Therefore, iP was added to the P-deficient diets to make diets NB + iP, HNB + iP, and HM422 + iP with aP equal to that in diet M955. Overall (d 0 to 35), ADG and G:F were greater ( hulled and hull-less barley in isocaloric diets fed to young pigs. Pigs fed the diet with LPA M955 consumed 31% less P and excreted 78% less fecal P and 30% less fecal Ca than pigs fed the diet with NB + iP that was equal to diet M955 in aP. Therefore, LPA barley, especially M955 with 95% aP, will reduce the use of iP in swine diets, reduce P pollution from swine manure, and support the goal of achieving global P sustainability.

  1. Antisense expression of a gene encoding a calcium-binding protein ...

    PRAKASH

    using the transgenic approach. The transformation of ... methods using EhCaBP or AtCaM3 gene-specific primers in ... acetone) was added, mixed and incubated for 15–18 h in the dark at .... as expected from the design of the AtCaM3 antisense construct .... Thus, there seems to be a positive qualitative correlation between ...

  2. Calcium Orthophosphate Cements and Concretes

    Sergey V. Dorozhkin

    2009-03-01

    Full Text Available In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are a bioactive and biodegradable grafting material in the form of a powder and a liquid. Both phases form after mixing a viscous paste that after being implanted, sets and hardens within the body as either a non-stoichiometric calcium deficient hydroxyapatite (CDHA or brushite, sometimes blended with unreacted particles and other phases. As both CDHA and brushite are remarkably biocompartible and bioresorbable (therefore, in vivo they can be replaced with newly forming bone, calcium orthophosphate cements represent a good correction technique for non-weight-bearing bone fractures or defects and appear to be very promising materials for bone grafting applications. Besides, these cements possess an excellent osteoconductivity, molding capabilities and easy manipulation. Furthermore, reinforced cement formulations are available, which in a certain sense might be described as calcium orthophosphate concretes. The concepts established by calcium orthophosphate cement pioneers in the early 1980s were used as a platform to initiate a new generation of bone substitute materials for commercialization. Since then, advances have been made in the composition, performance and manufacturing; several beneficial formulations have already been introduced as a result. Many other compositions are in experimental stages. In this review, an insight into calcium orthophosphate cements and concretes, as excellent biomaterials suitable for both dental and bone grafting application, has been provided.

  3. Economic modeling using evolutionary algorithms : the effect of binary encoding of strategies

    Waltman, L.R.; Eck, van N.J.; Dekker, Rommert; Kaymak, U.

    2011-01-01

    We are concerned with evolutionary algorithms that are employed for economic modeling purposes. We focus in particular on evolutionary algorithms that use a binary encoding of strategies. These algorithms, commonly referred to as genetic algorithms, are popular in agent-based computational economics

  4. Nucleases Encoded by Integraded Elements CJIE2 and CJIE4 Inhibit Natural Transformation of Campylobacter Jejuni

    Gaasbeek, E.J.; Wagenaar, J.A.; Guilhabert, M.R.; Putten, van J.P.; Parker, C.T.; Wal, van der F.J.

    2010-01-01

    The species Campylobacter jejuni is naturally competent for DNA uptake; nevertheless, nonnaturally transformable strains do exist. For a subset of strains we previously showed that a periplasmic DNase, encoded by dns, inhibits natural transformation in C. jejuni. In the present study, genetic

  5. The Arabic Diatessaron Project: Digitalizing, Encoding, Lemmatization

    Giuliano Lancioni

    2016-04-01

    Full Text Available The Arabic Diatessaron Project (henceforth ADP is an international research project in Digital Humanities that aims to collect, digitalise and encode all known manuscripts of the Arabic Diatessaron (henceforth AD, a text that has been relatively neglected in scholarly research. ADP’s final goal is to provide a number of tools that can enable scholars to effectively query, compare and investigate all known variants of the text that will be encoded as far as possible in compliance with the Text Encoding Initiative (TEI guidelines. The paper addresses a number of issues involved in the process of digitalising manuscripts included in the two existing editions (Ciasca 1888 and Marmardji 1935, adding variants in unedited manuscripts, encoding and lemmatising the text. Issues involved in the design of the ADP include presentation of variants, choice of the standard text, applicability of TEI guidelines, automatic translation between different encodings, cross-edition concordances and principles of lemmatisation.

  6. 21 CFR 184.1207 - Calcium lactate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium lactate. 184.1207 Section 184.1207 Food and... Substances Affirmed as GRAS § 184.1207 Calcium lactate. (a) Calcium lactate (C6H10CaO6.xH2O, where x is any... calcium carbonate or calcium hydroxide. (b) The ingredient meets the specifications of the Food Chemicals...

  7. Mitochondrial Calcium Dysregulation Contributes to Dendrite Degeneration Mediated by PD/LBD-Associated LRRK2 Mutants.

    Verma, Manish; Callio, Jason; Otero, P Anthony; Sekler, Israel; Wills, Zachary P; Chu, Charleen T

    2017-11-15

    common features of Parkinson's disease (PD), causing significant disability. Mutations in LRRK2 represent the most common known genetic cause of PD. We found that PD-linked LRRK2 mutations increased dendritic and mitochondrial calcium uptake in cortical neurons and familial PD patient fibroblasts, accompanied by increased expression of the mitochondrial calcium transporter MCU. Blocking the ERK1/2-dependent upregulation of MCU conferred protection against mutant LRRK2-elicited dendrite shortening, as did inhibiting MCU-mediated calcium import. Conversely, stimulating the export of calcium from mitochondria was also neuroprotective. These results implicate increased susceptibility to mitochondrial calcium overload in LRRK2-driven neurodegeneration, and suggest possible interventions that may slow the progression of cognitive dysfunction in PD. Copyright © 2017 the authors 0270-6474/17/3711152-15$15.00/0.

  8. An Encoding Technique for Multiobjective Evolutionary Algorithms Applied to Power Distribution System Reconfiguration

    J. L. Guardado

    2014-01-01

    Full Text Available Network reconfiguration is an alternative to reduce power losses and optimize the operation of power distribution systems. In this paper, an encoding scheme for evolutionary algorithms is proposed in order to search efficiently for the Pareto-optimal solutions during the reconfiguration of power distribution systems considering multiobjective optimization. The encoding scheme is based on the edge window decoder (EWD technique, which was embedded in the Strength Pareto Evolutionary Algorithm 2 (SPEA2 and the Nondominated Sorting Genetic Algorithm II (NSGA-II. The effectiveness of the encoding scheme was proved by solving a test problem for which the true Pareto-optimal solutions are known in advance. In order to prove the practicability of the encoding scheme, a real distribution system was used to find the near Pareto-optimal solutions for different objective functions to optimize.

  9. An encoding technique for multiobjective evolutionary algorithms applied to power distribution system reconfiguration.

    Guardado, J L; Rivas-Davalos, F; Torres, J; Maximov, S; Melgoza, E

    2014-01-01

    Network reconfiguration is an alternative to reduce power losses and optimize the operation of power distribution systems. In this paper, an encoding scheme for evolutionary algorithms is proposed in order to search efficiently for the Pareto-optimal solutions during the reconfiguration of power distribution systems considering multiobjective optimization. The encoding scheme is based on the edge window decoder (EWD) technique, which was embedded in the Strength Pareto Evolutionary Algorithm 2 (SPEA2) and the Nondominated Sorting Genetic Algorithm II (NSGA-II). The effectiveness of the encoding scheme was proved by solving a test problem for which the true Pareto-optimal solutions are known in advance. In order to prove the practicability of the encoding scheme, a real distribution system was used to find the near Pareto-optimal solutions for different objective functions to optimize.

  10. Selection of common bean lines with high grain yield and high grain calcium and iron concentrations

    Nerinéia Dalfollo Ribeiro

    2014-02-01

    Full Text Available Genetic improvement of common bean nutritional quality has advantages in marketing and can contribute to society as a food source. The objective of this study was to evaluate the genetic variability for grain yield, calcium and iron concentrations in grains of inbred common bean lines obtained by different breeding methods. For this, 136 F7 inbred lines were obtained using the Pedigree method and 136 F7 inbred lines were obtained using the Single-Seed Descent (SSD method. The lines showed genetic variability for grain yield, and concentrations of calcium and iron independently of the method of advancing segregating populations. The Pedigree method allows obtaining a greater number of lines with high grain yield. Selection using the SSD method allows the identification of a larger number of lines with high concentrations of calcium and iron in grains. Weak negative correlations were found between grain yield and calcium concentration (r = -0.0994 and grain yield and iron concentration (r = -0.3926. Several lines show genetic superiority for grain yield and concentrations of calcium and iron in grains and their selection can result in new common bean cultivars with high nutritional quality.

  11. A model for visual memory encoding.

    Rodolphe Nenert

    Full Text Available Memory encoding engages multiple concurrent and sequential processes. While the individual processes involved in successful encoding have been examined in many studies, a sequence of events and the importance of modules associated with memory encoding has not been established. For this reason, we sought to perform a comprehensive examination of the network for memory encoding using data driven methods and to determine the directionality of the information flow in order to build a viable model of visual memory encoding. Forty healthy controls ages 19-59 performed a visual scene encoding task. FMRI data were preprocessed using SPM8 and then processed using independent component analysis (ICA with the reliability of the identified components confirmed using ICASSO as implemented in GIFT. The directionality of the information flow was examined using Granger causality analyses (GCA. All participants performed the fMRI task well above the chance level (>90% correct on both active and control conditions and the post-fMRI testing recall revealed correct memory encoding at 86.33 ± 5.83%. ICA identified involvement of components of five different networks in the process of memory encoding, and the GCA allowed for the directionality of the information flow to be assessed, from visual cortex via ventral stream to the attention network and then to the default mode network (DMN. Two additional networks involved in this process were the cerebellar and the auditory-insular network. This study provides evidence that successful visual memory encoding is dependent on multiple modules that are part of other networks that are only indirectly related to the main process. This model may help to identify the node(s of the network that are affected by a specific disease processes and explain the presence of memory encoding difficulties in patients in whom focal or global network dysfunction exists.

  12. A model for visual memory encoding.

    Nenert, Rodolphe; Allendorfer, Jane B; Szaflarski, Jerzy P

    2014-01-01

    Memory encoding engages multiple concurrent and sequential processes. While the individual processes involved in successful encoding have been examined in many studies, a sequence of events and the importance of modules associated with memory encoding has not been established. For this reason, we sought to perform a comprehensive examination of the network for memory encoding using data driven methods and to determine the directionality of the information flow in order to build a viable model of visual memory encoding. Forty healthy controls ages 19-59 performed a visual scene encoding task. FMRI data were preprocessed using SPM8 and then processed using independent component analysis (ICA) with the reliability of the identified components confirmed using ICASSO as implemented in GIFT. The directionality of the information flow was examined using Granger causality analyses (GCA). All participants performed the fMRI task well above the chance level (>90% correct on both active and control conditions) and the post-fMRI testing recall revealed correct memory encoding at 86.33 ± 5.83%. ICA identified involvement of components of five different networks in the process of memory encoding, and the GCA allowed for the directionality of the information flow to be assessed, from visual cortex via ventral stream to the attention network and then to the default mode network (DMN). Two additional networks involved in this process were the cerebellar and the auditory-insular network. This study provides evidence that successful visual memory encoding is dependent on multiple modules that are part of other networks that are only indirectly related to the main process. This model may help to identify the node(s) of the network that are affected by a specific disease processes and explain the presence of memory encoding difficulties in patients in whom focal or global network dysfunction exists.

  13. Drosophila wing imaginal discs respond to mechanical injury via slow InsP3R-mediated intercellular calcium waves

    Restrepo, Simon; Basler, Konrad

    2016-08-01

    Calcium signalling is a highly versatile cellular communication system that modulates basic functions such as cell contractility, essential steps of animal development such as fertilization and higher-order processes such as memory. We probed the function of calcium signalling in Drosophila wing imaginal discs through a combination of ex vivo and in vivo imaging and genetic analysis. Here we discover that wing discs display slow, long-range intercellular calcium waves (ICWs) when mechanically stressed in vivo or cultured ex vivo. These slow imaginal disc intercellular calcium waves (SIDICs) are mediated by the inositol-3-phosphate receptor, the endoplasmic reticulum (ER) calcium pump SERCA and the key gap junction component Inx2. The knockdown of genes required for SIDIC formation and propagation negatively affects wing disc recovery after mechanical injury. Our results reveal a role for ICWs in wing disc homoeostasis and highlight the utility of the wing disc as a model for calcium signalling studies.

  14. Why Calcium? How Calcium Became the Best Communicator*

    Carafoli, Ernesto; Krebs, Joachim

    2016-01-01

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations, e.g. magnesium. Its free concentration within cells can thus be maintained at the very low levels demanded by the signaling function. A large cadre of proteins has evolved to bind or transport calcium. They all contribute to buffer it within cells, but a number of them also decode its message for the benefit of the target. The most important of these “calcium sensors” are the EF-hand proteins. Calcium is an ambivalent messenger. Although essential to the correct functioning of cell processes, if not carefully controlled spatially and temporally within cells, it generates variously severe cell dysfunctions, and even cell death. PMID:27462077

  15. Why Calcium? How Calcium Became the Best Communicator.

    Carafoli, Ernesto; Krebs, Joachim

    2016-09-30

    Calcium carries messages to virtually all important functions of cells. Although it was already active in unicellular organisms, its role became universally important after the transition to multicellular life. In this Minireview, we explore how calcium ended up in this privileged position. Most likely its unique coordination chemistry was a decisive factor as it makes its binding by complex molecules particularly easy even in the presence of large excesses of other cations, e.g. magnesium. Its free concentration within cells can thus be maintained at the very low levels demanded by the signaling function. A large cadre of proteins has evolved to bind or transport calcium. They all contribute to buffer it within cells, but a number of them also decode its message for the benefit of the target. The most important of these "calcium sensors" are the EF-hand proteins. Calcium is an ambivalent messenger. Although essential to the correct functioning of cell processes, if not carefully controlled spatially and temporally within cells, it generates variously severe cell dysfunctions, and even cell death. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

  16. Testosterone increases urinary calcium excretion and inhibits expression of renal calcium transport proteins.

    Hsu, Y.J.; Dimke, H.; Schoeber, J.P.H.; Hsu, S.C.; Lin, S.H.; Chu, P.; Hoenderop, J.G.J.; Bindels, R.J.M.

    2010-01-01

    Although gender differences in the renal handling of calcium have been reported, the overall contribution of androgens to these differences remains uncertain. We determined here whether testosterone affects active renal calcium reabsorption by regulating calcium transport proteins. Male mice had

  17. Calcium: the molecular basis of calcium action in biology and medicine

    Pochet, Roland; Donato, Rosario

    2000-01-01

    ... of Calcium Calcium Signalling in Excitable Cells Ca2+ Release in Muscle Cells by N. Macrez and J. Mironneau Calcium Signalling in Neurons Exemplified by Rat Sympathetic Ganglion Cells by S.J. M...

  18. Encoding of coordination complexes with XML.

    Vinoth, P; Sankar, P

    2017-09-01

    An in-silico system to encode structure, bonding and properties of coordination complexes is developed. The encoding is achieved through a semantic XML markup frame. Composition of the coordination complexes is captured in terms of central atom and ligands. Structural information of central atom is detailed in terms of electron status of valence electron orbitals. The ligands are encoded with specific reference to the electron environment of ligand centre atoms. Behaviour of ligands to form low or high spin complexes is accomplished by assigning a Ligand Centre Value to every ligand based on the electronic environment of ligand centre atom. Chemical ontologies are used for categorization purpose and to control different hybridization schemes. Complexes formed by the central atoms of transition metal, non-transition elements belonging to s-block, p-block and f-block are encoded with a generic encoding platform. Complexes of homoleptic, heteroleptic and bridged types are also covered by this encoding system. Utility of the encoded system to predict redox electron transfer reaction in the coordination complexes is demonstrated with a simple application. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Eye movements of the murine P/Q calcium channel mutant Tottering, and the impact of aging

    J.S. Stahl (J.); R.A. James (Robert); B.S. Oommen (Brian); F.E. Hoebeek (Freek); C.I. de Zeeuw (Chris)

    2006-01-01

    textabstractMice carrying mutations of the gene encoding the ion pore of the P/Q calcium channel (Cacna1a) are an instance in which cerebellar dysfunction may be attributable to altered electrophysiology and thus provide an opportunity to study how neuronal intrinsic properties dictate signal

  20. Genetic algorithms

    Wang, Lui; Bayer, Steven E.

    1991-01-01

    Genetic algorithms are mathematical, highly parallel, adaptive search procedures (i.e., problem solving methods) based loosely on the processes of natural genetics and Darwinian survival of the fittest. Basic genetic algorithms concepts are introduced, genetic algorithm applications are introduced, and results are presented from a project to develop a software tool that will enable the widespread use of genetic algorithm technology.

  1. Encoding entanglement-assisted quantum stabilizer codes

    Wang Yun-Jiang; Bai Bao-Ming; Li Zhuo; Xiao He-Ling; Peng Jin-Ye

    2012-01-01

    We address the problem of encoding entanglement-assisted (EA) quantum error-correcting codes (QECCs) and of the corresponding complexity. We present an iterative algorithm from which a quantum circuit composed of CNOT, H, and S gates can be derived directly with complexity O(n 2 ) to encode the qubits being sent. Moreover, we derive the number of each gate consumed in our algorithm according to which we can design EA QECCs with low encoding complexity. Another advantage brought by our algorithm is the easiness and efficiency of programming on classical computers. (general)

  2. Stochastic Simulation of Cardiac Ventricular Myocyte Calcium Dynamics and Waves

    Tuan, Hoang-Trong Minh; Williams, George S. B.; Chikando, Aristide C.; Sobie, Eric A.; Lederer, W. Jonathan; Jafri, M. Saleet

    2011-01-01

    A three dimensional model of calcium dynamics in the rat ventricular myocyte was developed to study the mechanism of calcium homeostasis and pathological calcium dynamics during calcium overload. The model contains 20,000 calcium release units (CRUs) each containing 49 ryanodine receptors. The model simulates calcium sparks with a realistic spontaneous calcium spark rate. It suggests that in addition to the calcium spark-based leak, there is an invisible calcium leak caused by the stochastic ...

  3. Lead in calcium supplements (abstract)

    Rehman, S.; Khalid, N.

    2011-01-01

    Lead present in calcium supplements is of grave concern as some lead levels have been measured up to the extent of regulatory limit set by the United States. Calcium supplements inevitably get contaminated with lead as both are naturally occurring elements. Therefore, it is imperative to indicate its level in these supplements in order to create awareness among consumers. In this study, a sophisticated analytical technique, atomic absorption spectrometry was used to analyze Pb contents in 27 commonly consumed Ca supplements manufactured by different national and multinational companies. The daily intake of lead through these supplements was calculated. Only 10% of the calcium supplements analyzed met the criteria of acceptable Pb levels (1.5 mu g/daily dose) in supplements/consumer products set by the United States. It was also found that Pb intake was highest in chelated calcium supplements 28.5 mu g/daily dose, whereas lowest 0.47 mu g/daily dose through calcium supplements with vitamin D formulation. In order to validate our results from the study conducted, IAEA-certified reference material (animal bone, H-5) was analyzed for its Pb levels. The levels of Pb determined were quite in good agreement with the certified values. (author)

  4. Isomorfic Substitutions of Calcium by Strontium in Calcium Hydroxyapatite

    Christensen, Hilbert

    1962-12-15

    By means of homogeneous precipitation it has been possible to synthesize crystalline solid solutions of calcium strontium hydroxyapatite from aqueous solutions. The lattice constants for the solid solutions were measured in the range Ca{sub 9}Sr(PO{sub 4}){sub 6}(OH){sub 2} - CaSr{sub 9}(PO{sub 4}){sub 6}(OH){sub 2}. The investigations show that the discrimination of strontium against calcium is considerably smaller than reported elsewhere (1). Strontium is preferentially built into the c-axis direction of the apatite lattice.

  5. LKB1 Regulates Mitochondria-Dependent Presynaptic Calcium Clearance and Neurotransmitter Release Properties at Excitatory Synapses along Cortical Axons.

    Kwon, Seok-Kyu; Sando, Richard; Lewis, Tommy L; Hirabayashi, Yusuke; Maximov, Anton; Polleux, Franck

    2016-07-01

    Individual synapses vary significantly in their neurotransmitter release properties, which underlie complex information processing in neural circuits. Presynaptic Ca2+ homeostasis plays a critical role in specifying neurotransmitter release properties, but the mechanisms regulating synapse-specific Ca2+ homeostasis in the mammalian brain are still poorly understood. Using electrophysiology and genetically encoded Ca2+ sensors targeted to the mitochondrial matrix or to presynaptic boutons of cortical pyramidal neurons, we demonstrate that the presence or absence of mitochondria at presynaptic boutons dictates neurotransmitter release properties through Mitochondrial Calcium Uniporter (MCU)-dependent Ca2+ clearance. We demonstrate that the serine/threonine kinase LKB1 regulates MCU expression, mitochondria-dependent Ca2+ clearance, and thereby, presynaptic release properties. Re-establishment of MCU-dependent mitochondrial Ca2+ uptake at glutamatergic synapses rescues the altered neurotransmitter release properties characterizing LKB1-null cortical axons. Our results provide novel insights into the cellular and molecular mechanisms whereby mitochondria control neurotransmitter release properties in a bouton-specific way through presynaptic Ca2+ clearance.

  6. The functions of store-operated calcium channels.

    Putney, James W; Steinckwich-Besançon, Natacha; Numaga-Tomita, Takuro; Davis, Felicity M; Desai, Pooja N; D'Agostin, Diane M; Wu, Shilan; Bird, Gary S

    2017-06-01

    Store-operated calcium channels provide calcium signals to the cytoplasm of a wide variety of cell types. The basic components of this signaling mechanism include a mechanism for discharging Ca 2+ stores (commonly but not exclusively phospholipase C and inositol 1,4,5-trisphosphate), a sensor in the endoplasmic reticulum that also serves as an activator of the plasma membrane channel (STIM1 and STIM2), and the store-operated channel (Orai1, 2 or 3). The advent of mice genetically altered to reduce store-operated calcium entry globally or in specific cell types has provided important tools to understand the functions of these widely encountered channels in specific and clinically important physiological systems. This review briefly discusses the history and cellular properties of store-operated calcium channels, and summarizes selected studies of their physiological functions in specific physiological or pathological contexts. This article is part of a Special Issue entitled: ECS Meeting edited by Claus Heizmann, Joachim Krebs and Jacques Haiech. Published by Elsevier B.V.

  7. Can natural selection encode Bayesian priors?

    Ramírez, Juan Camilo; Marshall, James A R

    2017-08-07

    The evolutionary success of many organisms depends on their ability to make decisions based on estimates of the state of their environment (e.g., predation risk) from uncertain information. These decision problems have optimal solutions and individuals in nature are expected to evolve the behavioural mechanisms to make decisions as if using the optimal solutions. Bayesian inference is the optimal method to produce estimates from uncertain data, thus natural selection is expected to favour individuals with the behavioural mechanisms to make decisions as if they were computing Bayesian estimates in typically-experienced environments, although this does not necessarily imply that favoured decision-makers do perform Bayesian computations exactly. Each individual should evolve to behave as if updating a prior estimate of the unknown environment variable to a posterior estimate as it collects evidence. The prior estimate represents the decision-maker's default belief regarding the environment variable, i.e., the individual's default 'worldview' of the environment. This default belief has been hypothesised to be shaped by natural selection and represent the environment experienced by the individual's ancestors. We present an evolutionary model to explore how accurately Bayesian prior estimates can be encoded genetically and shaped by natural selection when decision-makers learn from uncertain information. The model simulates the evolution of a population of individuals that are required to estimate the probability of an event. Every individual has a prior estimate of this probability and collects noisy cues from the environment in order to update its prior belief to a Bayesian posterior estimate with the evidence gained. The prior is inherited and passed on to offspring. Fitness increases with the accuracy of the posterior estimates produced. Simulations show that prior estimates become accurate over evolutionary time. In addition to these 'Bayesian' individuals, we also

  8. Genetic Mapping

    ... greatly advanced genetics research. The improved quality of genetic data has reduced the time required to identify a ... cases, a matter of months or even weeks. Genetic mapping data generated by the HGP's laboratories is freely accessible ...

  9. Chemical Space of DNA-Encoded Libraries.

    Franzini, Raphael M; Randolph, Cassie

    2016-07-28

    In recent years, DNA-encoded chemical libraries (DECLs) have attracted considerable attention as a potential discovery tool in drug development. Screening encoded libraries may offer advantages over conventional hit discovery approaches and has the potential to complement such methods in pharmaceutical research. As a result of the increased application of encoded libraries in drug discovery, a growing number of hit compounds are emerging in scientific literature. In this review we evaluate reported encoded library-derived structures and identify general trends of these compounds in relation to library design parameters. We in particular emphasize the combinatorial nature of these libraries. Generally, the reported molecules demonstrate the ability of this technology to afford hits suitable for further lead development, and on the basis of them, we derive guidelines for DECL design.

  10. Encoding information using laguerre gaussian modes

    Trichili, A

    2015-08-01

    Full Text Available The authors experimentally demonstrate an information encoding protocol using the two degrees of freedom of Laguerre Gaussian modes having different radial and azimuthal components. A novel method, based on digital holography, for information...

  11. Molecular mechanisms for protein-encoded inheritance

    Wiltzius, Jed J. W.; Landau, Meytal; Nelson, Rebecca; Sawaya, Michael R.; Apostol, Marcin I.; Goldschmidt, Lukasz; Soriaga, Angela B.; Cascio, Duilio; Rajashankar, Kanagalaghatta; Eisenberg, David

    2013-01-01

    Strains are phenotypic variants, encoded by nucleic acid sequences in chromosomal inheritance and by protein “conformations” in prion inheritance and transmission. But how is a protein “conformation” stable enough to endure transmission between cells or organisms? Here new polymorphic crystal structures of segments of prion and other amyloid proteins offer structural mechanisms for prion strains. In packing polymorphism, prion strains are encoded by alternative packings (polymorphs) of β-sheets formed by the same segment of a protein; in a second mechanism, segmental polymorphism, prion strains are encoded by distinct β-sheets built from different segments of a protein. Both forms of polymorphism can produce enduring “conformations,” capable of encoding strains. These molecular mechanisms for transfer of information into prion strains share features with the familiar mechanism for transfer of information by nucleic acid inheritance, including sequence specificity and recognition by non-covalent bonds. PMID:19684598

  12. Electrophysical properties of calcium vanadates

    Krasnenko, T.I.; Fotiev, A.A.

    1983-01-01

    Electrophysical properties of calcium vanadates are studied for the case of alteration of external parameters of the medium (PO 2 , T). It is lshown that structural transformations bring about changes in the nature of electrophysical properties of Ca 2 V 2 O 7 , Ca 3 (VO 4 ) 2 , this being the reason for charge redistribution in anion groupings. It is obvious, that the general conductivity of calcium methavanadate is mainly caused by ion transport. Ca(VO 3 ) 2 possesses amphoteric character of semiconducting properties: the type of conductivity changes from ''p'' to ''n'' with temperature increase. Polytherms of conductivity and sums of ion numbers of Ca 2 V 2 O 7 transition are given. It is established that calcium pyrovanadate has a mixed electron-ion conductivity

  13. Preparation of calcium phosphate paste

    Mohd Reusmaazran Yusof; Norzita Yaacob; Idris Besar; Che Seman Mahmood; Rusnah Mustafa

    2010-01-01

    Calcium phosphate paste were prepared by mixing between calcium sodium potassium phosphate, Ca 2 NaK (PO 4 ) 2 (CSPP) and monocalcium phosphate monohydrate, Ca(H 2 PO 4 ) 2 .H 2 O (MCPM). CSPP were obtained by reaction between calcium hydrogen phosphate (CaHPO 4 ), potassium carbonate (K 2 CO 3 ) and sodium carbonate (Na 2 CO 3 ) in solid state sintering process followed by quenching in air at 1000 degree Celsius. The paste was aging in simulated body fluid (SBF) for 0.5, 1, 3, 6, 12, 24, 48 hrs, 3, 7 and 14 days. The morphological investigation indicated the formation of apatite crystal were first growth after 24 hours. The obvious growth of apatite crystal was shown at 3 days. The obvious growth of apatite crystal was shown in 7 and 14 days indicated the prediction of paste would have rapid reaction with bone after implantation. (author)

  14. A linear-encoding model explains the variability of the target morphology in regeneration

    Lobo, Daniel; Solano, Mauricio; Bubenik, George A.; Levin, Michael

    2014-01-01

    A fundamental assumption of today's molecular genetics paradigm is that complex morphology emerges from the combined activity of low-level processes involving proteins and nucleic acids. An inherent characteristic of such nonlinear encodings is the difficulty of creating the genetic and epigenetic information that will produce a given self-assembling complex morphology. This ‘inverse problem’ is vital not only for understanding the evolution, development and regeneration of bodyplans, but also for synthetic biology efforts that seek to engineer biological shapes. Importantly, the regenerative mechanisms in deer antlers, planarian worms and fiddler crabs can solve an inverse problem: their target morphology can be altered specifically and stably by injuries in particular locations. Here, we discuss the class of models that use pre-specified morphological goal states and propose the existence of a linear encoding of the target morphology, making the inverse problem easy for these organisms to solve. Indeed, many model organisms such as Drosophila, hydra and Xenopus also develop according to nonlinear encodings producing linear encodings of their final morphologies. We propose the development of testable models of regeneration regulation that combine emergence with a top-down specification of shape by linear encodings of target morphology, driving transformative applications in biomedicine and synthetic bioengineering. PMID:24402915

  15. Quantum Logical Operations on Encoded Qubits

    Zurek, W.H.; Laflamme, R.

    1996-01-01

    We show how to carry out quantum logical operations (controlled-not and Toffoli gates) on encoded qubits for several encodings which protect against various 1-bit errors. This improves the reliability of these operations by allowing one to correct for 1-bit errors which either preexisted or occurred in the course of operation. The logical operations we consider allow one to carry out the vast majority of the steps in the quantum factoring algorithm. copyright 1996 The American Physical Society

  16. Using XML to encode TMA DES metadata

    Oliver Lyttleton

    2011-01-01

    Full Text Available Background: The Tissue Microarray Data Exchange Specification (TMA DES is an XML specification for encoding TMA experiment data. While TMA DES data is encoded in XML, the files that describe its syntax, structure, and semantics are not. The DTD format is used to describe the syntax and structure of TMA DES, and the ISO 11179 format is used to define the semantics of TMA DES. However, XML Schema can be used in place of DTDs, and another XML encoded format, RDF, can be used in place of ISO 11179. Encoding all TMA DES data and metadata in XML would simplify the development and usage of programs which validate and parse TMA DES data. XML Schema has advantages over DTDs such as support for data types, and a more powerful means of specifying constraints on data values. An advantage of RDF encoded in XML over ISO 11179 is that XML defines rules for encoding data, whereas ISO 11179 does not. Materials and Methods: We created an XML Schema version of the TMA DES DTD. We wrote a program that converted ISO 11179 definitions to RDF encoded in XML, and used it to convert the TMA DES ISO 11179 definitions to RDF. Results: We validated a sample TMA DES XML file that was supplied with the publication that originally specified TMA DES using our XML Schema. We successfully validated the RDF produced by our ISO 11179 converter with the W3C RDF validation service. Conclusions: All TMA DES data could be encoded using XML, which simplifies its processing. XML Schema allows datatypes and valid value ranges to be specified for CDEs, which enables a wider range of error checking to be performed using XML Schemas than could be performed using DTDs.

  17. Using XML to encode TMA DES metadata.

    Lyttleton, Oliver; Wright, Alexander; Treanor, Darren; Lewis, Paul

    2011-01-01

    The Tissue Microarray Data Exchange Specification (TMA DES) is an XML specification for encoding TMA experiment data. While TMA DES data is encoded in XML, the files that describe its syntax, structure, and semantics are not. The DTD format is used to describe the syntax and structure of TMA DES, and the ISO 11179 format is used to define the semantics of TMA DES. However, XML Schema can be used in place of DTDs, and another XML encoded format, RDF, can be used in place of ISO 11179. Encoding all TMA DES data and metadata in XML would simplify the development and usage of programs which validate and parse TMA DES data. XML Schema has advantages over DTDs such as support for data types, and a more powerful means of specifying constraints on data values. An advantage of RDF encoded in XML over ISO 11179 is that XML defines rules for encoding data, whereas ISO 11179 does not. We created an XML Schema version of the TMA DES DTD. We wrote a program that converted ISO 11179 definitions to RDF encoded in XML, and used it to convert the TMA DES ISO 11179 definitions to RDF. We validated a sample TMA DES XML file that was supplied with the publication that originally specified TMA DES using our XML Schema. We successfully validated the RDF produced by our ISO 11179 converter with the W3C RDF validation service. All TMA DES data could be encoded using XML, which simplifies its processing. XML Schema allows datatypes and valid value ranges to be specified for CDEs, which enables a wider range of error checking to be performed using XML Schemas than could be performed using DTDs.

  18. Using XML to encode TMA DES metadata

    Lyttleton, Oliver; Wright, Alexander; Treanor, Darren; Lewis, Paul

    2011-01-01

    Background: The Tissue Microarray Data Exchange Specification (TMA DES) is an XML specification for encoding TMA experiment data. While TMA DES data is encoded in XML, the files that describe its syntax, structure, and semantics are not. The DTD format is used to describe the syntax and structure of TMA DES, and the ISO 11179 format is used to define the semantics of TMA DES. However, XML Schema can be used in place of DTDs, and another XML encoded format, RDF, can be used in place of ISO 11179. Encoding all TMA DES data and metadata in XML would simplify the development and usage of programs which validate and parse TMA DES data. XML Schema has advantages over DTDs such as support for data types, and a more powerful means of specifying constraints on data values. An advantage of RDF encoded in XML over ISO 11179 is that XML defines rules for encoding data, whereas ISO 11179 does not. Materials and Methods: We created an XML Schema version of the TMA DES DTD. We wrote a program that converted ISO 11179 definitions to RDF encoded in XML, and used it to convert the TMA DES ISO 11179 definitions to RDF. Results: We validated a sample TMA DES XML file that was supplied with the publication that originally specified TMA DES using our XML Schema. We successfully validated the RDF produced by our ISO 11179 converter with the W3C RDF validation service. Conclusions: All TMA DES data could be encoded using XML, which simplifies its processing. XML Schema allows datatypes and valid value ranges to be specified for CDEs, which enables a wider range of error checking to be performed using XML Schemas than could be performed using DTDs. PMID:21969921

  19. Uptake of radiactive calcium by groundnut (Arachis hypogaea L. ) and efficiency of utilisation of applied calcium

    Loganathan, S; Krishnamoorthy, K K [Tamil Nadu Agricultural Univ., Coimbatore (India). Dept. of Soil Science and Agricultural Chemistry

    1977-04-01

    A pot experiment was conducted with groundnut applying labelled calcium as its sulphate and carbonate at two levels namely 75 and 150 kg Ca per ha with varying levels of P, K and Mg. Plant samples were taken at different stages of crop growth and analysed for the content of radioactive calcium. Calcium sulphate treatment has resulted in larger uptake of calcium compared to calcium carbonate. An application of 150 kg Ca per ha has caused significantly higher uptake by groundnut plant than 75 kg Ca per ha. The percentage of utilisation of added calcium ranged from 2.2 to 5.4 Recovery of calcium by plants was more in calcium sulphate treatment rather than in calcium carbonate. The plants showed a preference for absorbing applied calcium rather than native calcium.

  20. Uptake of radiactive calcium by groundnut (Arachis hypogaea L.) and efficiency of utilisation of applied calcium

    Loganathan, S.; Krishnamoorthy, K.K.

    1977-01-01

    A pot experiment was conducted with groundnut applying labelled calcium as its sulphate and carbonate at two levels namely 75 and 150 kg Ca per ha with varying levels of P, K and Mg. Plant samples were taken at different stages of crop growth and analysed for the content of radioactive calcium. Calcium sulphate treatment has resulted in larger uptake of calcium compared to calcium carbonate. An application of 150 kg Ca per ha has caused significantly higher uptake by groundnut plant than 75 kg Ca per ha. The percentage of utilisation of added calcium ranged from 2.2 to 5.4 Recovery of calcium by plants was more in calcium sulphate treatment rather than in calcium carbonate. The plants showed a preference for absorbing applied calcium rather than native calcium

  1. The effect of habitat geology on calcium intake and calcium status of wild rodents.

    Shore, R F; Balment, R J; Yalden, D W

    1991-12-01

    Calcium is essential for normal physiological function, reproduction and growth in mammals but its distribution in the natural environment is heterogeneous. Spatial variation in calcium soil content is especially marked in the Peak District, United Kingdom, where both calcium-rich limestone and calcium-poor gritstone rock types occur. Wood mice Apodemus sylvaticus (L) and bank voles Clethrionomys glareolus (Schreber 1780) from limestone areas had significantly higher calcium concentrations in stomach contents and in faeces compared with their counterparts from gritstone areas. Calcium status was assessed from serum calcium concentration, femur weight, ash content of the body, calcium concentration in the femur and body ash. There was no significant difference in serum calcium concentration, femur calcium concentration and body ash calcium concentration between animals from the limestone and the gritstone. However, on the limestone, bank voles, but not wood mice, had significantly heavier femora and a greater proportion of ash in the body compared with their gritstone counterparts.

  2. Calcium and Bone Metabolism Indices.

    Song, Lu

    2017-01-01

    Calcium and inorganic phosphate are of critical importance for many body functions, thus the regulations of their plasma concentrations are tightly controlled by the concerted actions of reabsorption/excretion in the kidney, absorption in the intestines, and exchange from bone, the major reservoir for calcium and phosphate in the body. Parathyroid hormone (PTH) and 1,25-dihydroxyvitamin D (1,25(OH) 2 D) control calcium homeostasis, whereas PTH, 1,25(OH) 2 D, and bone-derived fibroblast growth factor 23 (FGF 23) control phosphate homeostasis. Hypoparathyroidism can cause hypocalcemia and hyperphosphatemia, whereas deficient vitamin D actions can cause osteomalacia in adults and rickets in children. Hyperparathyroidism, alternatively, can cause hypercalcemia and hypophosphatemia. Laboratory tests of calcium, phosphate, PTH, and 25-hydroxyvitamin D are very useful in the diagnosis of abnormalities associated with calcium and/or phosphate metabolisms. Bone is constantly remodeled throughout life in response to mechanical stress and a need for calcium in extracellular fluids. Metabolic bone diseases such as osteoporosis, osteomalacia in adults or rickets in children, and renal osteodystrophy develop when bone resorption exceeds bone formation. Bone turnover markers (BTM) such as serum N-terminal propeptide of type I procollagen (P1NP) and C-terminal collagen cross-link (CTX) may be useful in predicting future fracture risk or monitoring the response to anti-resorptive therapy. There is a need to standardize sample collection protocols because certain BTMs exhibit large circadian variations and tend to be influenced by food intakes. In the United States, a project to standardize BTM sample collection protocols and to establish the reference intervals for serum P1NP and serum CTX is ongoing. We anticipate the outcome of this project to shine lights on the standardization of BTM assays, sample collection protocols, reference intervals in relation to age, sex, and ethnic

  3. Magnetically responsive calcium carbonate microcrystals.

    Fakhrullin, Rawil F; Bikmullin, Aidar G; Nurgaliev, Danis K

    2009-09-01

    Here we report the fabrication of magnetically responsive calcium carbonate microcrystals produced by coprecipitation of calcium carbonate in the presence of citrate-stabilized iron oxide nanoparticles. We demonstrate that the calcite microcrystals obtained possess superparamagnetic properties due to incorporated magnetite nanoparticles and can be manipulated by an external magnetic field. The microcrystals doped with magnetic nanoparticles were utilized as templates for the fabrication of hollow polyelectrolyte microcapsules, which retain the magnetic properties of the sacrificial cores and might be spatially manipulated using a permanent magnet, thus providing the magnetic-field-facilitated delivery and separation of materials templated on magnetically responsive calcite microcrystals.

  4. Genetic privacy.

    Sankar, Pamela

    2003-01-01

    During the past 10 years, the number of genetic tests performed more than tripled, and public concern about genetic privacy emerged. The majority of states and the U.S. government have passed regulations protecting genetic information. However, research has shown that concerns about genetic privacy are disproportionate to known instances of information misuse. Beliefs in genetic determinacy explain some of the heightened concern about genetic privacy. Discussion of the debate over genetic testing within families illustrates the most recent response to genetic privacy concerns.

  5. Intercellular calcium signaling is regulated by morphogens during Drosophila wing development

    Chen, Danny; Levis, Megan; Arredondo-Walsh, Ninfamaria; Zartman, Jeremiah; Brodskiy, Pavel; Wu, Qinfeng; Huizar, Francisco; Soundarrajan, Dharsan; Narciso, Cody; Chen, Jianxu; Liang, Peixian

    2017-01-01

    Organ development is driven by a set of patterned inductive signals. However, how these signals are integrated to coordinate tissue patterning is still poorly understood. Calcium ions (Ca2+) are critical signaling components involved in signal integration and are regulated by a core Ca2+ signaling toolkit. Ca2+ signaling encodes a significant fraction of information in cells through both amplitude and frequency-dependent regulation of transcription factors and key regulatory enzymes. A range ...

  6. Current View on Phytoplasma Genomes and Encoded Metabolism

    Michael Kube

    2012-01-01

    Full Text Available Phytoplasmas are specialised bacteria that are obligate parasites of plant phloem tissue and insects. These bacteria have resisted all attempts of cell-free cultivation. Genome research is of particular importance to analyse the genetic endowment of such bacteria. Here we review the gene content of the four completely sequenced ‘Candidatus Phytoplasma’ genomes that include those of ‘Ca. P. asteris’ strains OY-M and AY-WB, ‘Ca. P. australiense,’ and ‘Ca. P. mali’. These genomes are characterized by chromosome condensation resulting in sizes below 900 kb and a G + C content of less than 28%. Evolutionary adaption of the phytoplasmas to nutrient-rich environments resulted in losses of genetic modules and increased host dependency highlighted by the transport systems and limited metabolic repertoire. On the other hand, duplication and integration events enlarged the chromosomes and contribute to genome instability. Present differences in the content of membrane and secreted proteins reflect the host adaptation in the phytoplasma strains. General differences are obvious between different phylogenetic subgroups. ‘Ca. P. mali’ is separated from the other strains by its deviating chromosome organization, the genetic repertoire for recombination and excision repair of nucleotides or the loss of the complete energy-yielding part of the glycolysis. Apart from these differences, comparative analysis exemplified that all four phytoplasmas are likely to encode an alternative pathway to generate pyruvate and ATP.

  7. Automated quantification of neuronal networks and single-cell calcium dynamics using calcium imaging.

    Patel, Tapan P; Man, Karen; Firestein, Bonnie L; Meaney, David F

    2015-03-30

    Recent advances in genetically engineered calcium and membrane potential indicators provide the potential to estimate the activation dynamics of individual neurons within larger, mesoscale networks (100s-1000+neurons). However, a fully integrated automated workflow for the analysis and visualization of neural microcircuits from high speed fluorescence imaging data is lacking. Here we introduce FluoroSNNAP, Fluorescence Single Neuron and Network Analysis Package. FluoroSNNAP is an open-source, interactive software developed in MATLAB for automated quantification of numerous biologically relevant features of both the calcium dynamics of single-cells and network activity patterns. FluoroSNNAP integrates and improves upon existing tools for spike detection, synchronization analysis, and inference of functional connectivity, making it most useful to experimentalists with little or no programming knowledge. We apply FluoroSNNAP to characterize the activity patterns of neuronal microcircuits undergoing developmental maturation in vitro. Separately, we highlight the utility of single-cell analysis for phenotyping a mixed population of neurons expressing a human mutant variant of the microtubule associated protein tau and wild-type tau. We show the performance of semi-automated cell segmentation using spatiotemporal independent component analysis and significant improvement in detecting calcium transients using a template-based algorithm in comparison to peak-based or wavelet-based detection methods. Our software further enables automated analysis of microcircuits, which is an improvement over existing methods. We expect the dissemination of this software will facilitate a comprehensive analysis of neuronal networks, promoting the rapid interrogation of circuits in health and disease. Copyright © 2015. Published by Elsevier B.V.

  8. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes.

    Samigullin, Dmitry; Fatikhov, Nijaz; Khaziev, Eduard; Skorinkin, Andrey; Nikolsky, Eugeny; Bukharaeva, Ellya

    2014-01-01

    At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers-which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal-has hitherto been technically impossible. With the aim of quantifying both Ca(2+) currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 pA and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 μM and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity.

  9. Estimation of presynaptic calcium currents and endogenous calcium buffers at the frog neuromuscular junction with two different calcium fluorescent dyes

    Dmitry eSamigullin

    2015-01-01

    Full Text Available At the frog neuromuscular junction, under physiological conditions, the direct measurement of calcium currents and of the concentration of intracellular calcium buffers—which determine the kinetics of calcium concentration and neurotransmitter release from the nerve terminal—has hitherto been technically impossible. With the aim of quantifying both Ca2+ currents and the intracellular calcium buffers, we measured fluorescence signals from nerve terminals loaded with the low-affinity calcium dye Magnesium Green or the high-affinity dye Oregon Green BAPTA-1, simultaneously with microelectrode recordings of nerve-action potentials and end-plate currents. The action-potential-induced fluorescence signals in the nerve terminals developed much more slowly than the postsynaptic response. To clarify the reasons for this observation and to define a spatiotemporal profile of intracellular calcium and of the concentration of mobile and fixed calcium buffers, mathematical modeling was employed. The best approximations of the experimental calcium transients for both calcium dyes were obtained when the calcium current had an amplitude of 1.6 ± 0.08 рА and a half-decay time of 1.2 ± 0.06 ms, and when the concentrations of mobile and fixed calcium buffers were 250 ± 13 µM and 8 ± 0.4 mM, respectively. High concentrations of endogenous buffers define the time course of calcium transients after an action potential in the axoplasm, and may modify synaptic plasticity.

  10. Calcium electroporation in three cell lines; a comparison of bleomycin and calcium, calcium compounds, and pulsing conditions

    Frandsen, Stine Krog; Gissel, Hanne; Hojman, Pernille

    2013-01-01

    offers several advantages over standard treatment options: calcium is inexpensive and may readily be applied without special precautions, as is the case with cytostatic drugs. Therefore, details on the use of calcium electroporation are essential for carrying out clinical trials comparing calcium...

  11. Calcium fertilization increases the concentration of calcium in sapwood and calcium oxalate in foliage of red spruce

    Kevin T. Smith; Walter C. Shortle; Jon H. Connolly; Rakesh Minocha; Jody Jellison

    2009-01-01

    Calcium cycling plays a key role in the health and productivity of red spruce forests in the northeastern US. A portion of the flowpath of calcium within forests includes translocation as Ca2+ in sapwood and accumulation as crystals of calcium oxalate in foliage. Concentrations of Ca in these tree tissues have been used as markers of...

  12. Automated Functional Analysis of Astrocytes from Chronic Time-Lapse Calcium Imaging Data.

    Wang, Yinxue; Shi, Guilai; Miller, David J; Wang, Yizhi; Wang, Congchao; Broussard, Gerard; Wang, Yue; Tian, Lin; Yu, Guoqiang

    2017-01-01

    Recent discoveries that astrocytes exert proactive regulatory effects on neural information processing and that they are deeply involved in normal brain development and disease pathology have stimulated broad interest in understanding astrocyte functional roles in brain circuit. Measuring astrocyte functional status is now technically feasible, due to recent advances in modern microscopy and ultrasensitive cell-type specific genetically encoded Ca 2+ indicators for chronic imaging. However, there is a big gap between the capability of generating large dataset via calcium imaging and the availability of sophisticated analytical tools for decoding the astrocyte function. Current practice is essentially manual, which not only limits analysis throughput but also risks introducing bias and missing important information latent in complex, dynamic big data. Here, we report a suite of computational tools, called Functional AStrocyte Phenotyping (FASP), for automatically quantifying the functional status of astrocytes. Considering the complex nature of Ca 2+ signaling in astrocytes and low signal to noise ratio, FASP is designed with data-driven and probabilistic principles, to flexibly account for various patterns and to perform robustly with noisy data. In particular, FASP explicitly models signal propagation, which rules out the applicability of tools designed for other types of data. We demonstrate the effectiveness of FASP using extensive synthetic and real data sets. The findings by FASP were verified by manual inspection. FASP also detected signals that were missed by purely manual analysis but could be confirmed by more careful manual examination under the guidance of automatic analysis. All algorithms and the analysis pipeline are packaged into a plugin for Fiji (ImageJ), with the source code freely available online at https://github.com/VTcbil/FASP.

  13. An amplified promoter system for targeted expression of calcium indicator proteins in the cerebellar cortex

    Bernd eKuhn

    2012-07-01

    Full Text Available Recording of identified neuronal network activity using genetically encoded calcium indicators (GECIs requires labeling that is cell type-specific and bright enough for the detection of functional signals. However, specificity and strong expression are often not achievable using the same promoter. Here we present a combinatorial approach for targeted expression and single-cell-level quantification in which a weak promoter is used to drive trans-amplification under a strong general promoter. We demonstrated this approach using recombinant adeno-associated viruses (rAAVs to deliver the sequence of the GECI D3cpv in the mouse cerebellar cortex. Direct expression under the human synapsin promoter (hSYN led to high levels of expression (50-100 µM in five interneuron types of the cerebellar cortex but not in Purkinje cells (PCs (≤10 μM, yielding sufficient contrast to allow functional signals to be recorded from somata and processes in awake animals using two-photon microscopy. When the hSYN promoter was used to drive expression of the tetracycline transactivator (tTA, a second rAAV containing the bidirectional TET promoter (Ptetbi could drive strong D3cpv expression in PCs (10-300 µM, enough to allow reliable complex spike detection in the dendritic arbor. An amplified approach should be of use in monitoring neural processing in selected cell types and boosting expression of optogenetic probes. Additionally, we overcome cell toxicity associated with rAAV injection and/or local GECI overexpression by combining the virus injection with systemic pre-injection of hyperosmotic D-mannitol, and by this double the time window for functional imaging.

  14. Vitamin D, Calcium, and Bone Health

    ... Bone Health Featured Resource Find an Endocrinologist Search Vitamin D, Calcium, and Bone Health Download PDFs English ... also helps keep your bones strong. Why are vitamin D and calcium important to bone health? Vitamin ...

  15. Complex formation ions calcium with macromolecules pectin

    Khalikova, M.D.; Avloev, Kh.Kh.; Muhiddinov, Z.K.

    2005-01-01

    In clause the mechanism of sorption of ions of calcium by macromolecules of pectin is opened. Is shown, that the linkage of ions of calcium descends on acid bunches of pectin, and process carries cooperative character

  16. Atomic layer deposition of calcium oxide and calcium hafnium oxide films using calcium cyclopentadienyl precursor

    Kukli, Kaupo; Ritala, Mikko; Sajavaara, Timo; Haenninen, Timo; Leskelae, Markku

    2006-01-01

    Calcium oxide and calcium hafnium oxide thin films were grown by atomic layer deposition on borosilicate glass and silicon substrates in the temperature range of 205-300 o C. The calcium oxide films were grown from novel calcium cyclopentadienyl precursor and water. Calcium oxide films possessed refractive index 1.75-1.80. Calcium oxide films grown without Al 2 O 3 capping layer occurred hygroscopic and converted to Ca(OH) 2 after exposure to air. As-deposited CaO films were (200)-oriented. CaO covered with Al 2 O 3 capping layers contained relatively low amounts of hydrogen and re-oriented into (111) direction upon annealing at 900 o C. In order to examine the application of CaO in high-permittivity dielectric layers, mixtures of Ca and Hf oxides were grown by alternate CaO and HfO 2 growth cycles at 230 and 300 o C. HfCl 4 was used as a hafnium precursor. When grown at 230 o C, the films were amorphous with equal amounts of Ca and Hf constituents (15 at.%). These films crystallized upon annealing at 750 o C, showing X-ray diffraction peaks characteristic of hafnium-rich phases such as Ca 2 Hf 7 O 16 or Ca 6 Hf 19 O 44 . At 300 o C, the relative Ca content remained below 8 at.%. The crystallized phase well matched with rhombohedral Ca 2 Hf 7 O 16 . The dielectric films grown on Si(100) substrates possessed effective permittivity values in the range of 12.8-14.2

  17. Kinetics of calcium sulfoaluminate formation from tricalcium aluminate, calcium sulfate and calcium oxide

    Li, Xuerun; Zhang, Yu; Shen, Xiaodong; Wang, Qianqian; Pan, Zhigang

    2014-01-01

    The formation kinetics of tricalcium aluminate (C 3 A) and calcium sulfate yielding calcium sulfoaluminate (C 4 A 3 $) and the decomposition kinetics of calcium sulfoaluminate were investigated by sintering a mixture of synthetic C 3 A and gypsum. The quantitative analysis of the phase composition was performed by X-ray powder diffraction analysis using the Rietveld method. The results showed that the formation reaction 3Ca 3 Al 2 O 6 + CaSO 4 → Ca 4 Al 6 O 12 (SO 4 ) + 6CaO was the primary reaction 4 Al 6 O 12 (SO 4 ) + 10CaO → 6Ca 3 Al 2 O 6 + 2SO 2 ↑ + O 2 ↑ primarily occurred beyond 1350 °C with an activation energy of 792 ± 64 kJ/mol. The optimal formation region for C 4 A 3 $ was from 1150 °C to 1350 °C and from 6 h to 1 h, which could provide useful information on the formation of C 4 A 3 $ containing clinkers. The Jander diffusion model was feasible for the formation and decomposition of calcium sulfoaluminate. Ca 2+ and SO 4 2− were the diffusive species in both the formation and decomposition reactions. -- Highlights: •Formation and decomposition of calcium sulphoaluminate were studied. •Decomposition of calcium sulphoaluminate combined CaO and yielded C 3 A. •Activation energy for formation was 231 ± 42 kJ/mol. •Activation energy for decomposition was 792 ± 64 kJ/mol. •Both the formation and decomposition were controlled by diffusion

  18. ERP Correlates of Encoding Success and Encoding Selectivity in Attention Switching

    Yeung, Nick

    2016-01-01

    Long-term memory encoding depends critically on effective processing of incoming information. The degree to which participants engage in effective encoding can be indexed in electroencephalographic (EEG) data by studying event-related potential (ERP) subsequent memory effects. The current study investigated ERP correlates of memory success operationalised with two different measures—memory selectivity and global memory—to assess whether previously observed ERP subsequent memory effects reflect focused encoding of task-relevant information (memory selectivity), general encoding success (global memory), or both. Building on previous work, the present study combined an attention switching paradigm—in which participants were presented with compound object-word stimuli and switched between attending to the object or the word across trials—with a later recognition memory test for those stimuli, while recording their EEG. Our results provided clear evidence that subsequent memory effects resulted from selective attentional focusing and effective top-down control (memory selectivity) in contrast to more general encoding success effects (global memory). Further analyses addressed the question of whether successful encoding depended on similar control mechanisms to those involved in attention switching. Interestingly, differences in the ERP correlates of attention switching and successful encoding, particularly during the poststimulus period, indicated that variability in encoding success occurred independently of prestimulus demands for top-down cognitive control. These results suggest that while effects of selective attention and selective encoding co-occur behaviourally their ERP correlates are at least partly dissociable. PMID:27907075

  19. Multichannel compressive sensing MRI using noiselet encoding.

    Kamlesh Pawar

    Full Text Available The incoherence between measurement and sparsifying transform matrices and the restricted isometry property (RIP of measurement matrix are two of the key factors in determining the performance of compressive sensing (CS. In CS-MRI, the randomly under-sampled Fourier matrix is used as the measurement matrix and the wavelet transform is usually used as sparsifying transform matrix. However, the incoherence between the randomly under-sampled Fourier matrix and the wavelet matrix is not optimal, which can deteriorate the performance of CS-MRI. Using the mathematical result that noiselets are maximally incoherent with wavelets, this paper introduces the noiselet unitary bases as the measurement matrix to improve the incoherence and RIP in CS-MRI. Based on an empirical RIP analysis that compares the multichannel noiselet and multichannel Fourier measurement matrices in CS-MRI, we propose a multichannel compressive sensing (MCS framework to take the advantage of multichannel data acquisition used in MRI scanners. Simulations are presented in the MCS framework to compare the performance of noiselet encoding reconstructions and Fourier encoding reconstructions at different acceleration factors. The comparisons indicate that multichannel noiselet measurement matrix has better RIP than that of its Fourier counterpart, and that noiselet encoded MCS-MRI outperforms Fourier encoded MCS-MRI in preserving image resolution and can achieve higher acceleration factors. To demonstrate the feasibility of the proposed noiselet encoding scheme, a pulse sequences with tailored spatially selective RF excitation pulses was designed and implemented on a 3T scanner to acquire the data in the noiselet domain from a phantom and a human brain. The results indicate that noislet encoding preserves image resolution better than Fouirer encoding.

  20. Calcium channel blockers and Alzheimer's disease★

    Tan, Yi; Deng, Yulin; Qing, Hong

    2012-01-01

    Alzheimer's disease is characterized by two pathological hallmarks: amyloid plaques and neurofibrillary tangles. In addition, calcium homeostasis is disrupted in the course of human aging. Recent research shows that dense plaques can cause functional alteration of calcium signals in mice with Alzheimer's disease. Calcium channel blockers are effective therapeutics for treating Alzheimer's disease. This review provides an overview of the current research of calcium channel blockers involved in Alzheimer's disease therapy. PMID:25767489

  1. 21 CFR 184.1210 - Calcium oxide.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium oxide. 184.1210 Section 184.1210 Food and... Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8) is also known as lime, quick lime, burnt lime, or calx. It is produced from calcium carbonate, limestone, or...

  2. Oxalic acid decreases calcium absorption in rats

    Weaver, C.M.; Martin, B.R.; Ebner, J.S.; Krueger, C.A.

    1987-01-01

    Calcium absorption from salts and foods intrinsically labeled with 45 Ca was determined in the rat model. Calcium bioavailability was nearly 10 times greater for low oxalate kale, CaCO 3 and CaCl 2 than from CaC 2 O 4 (calcium oxalate) and spinach (high in oxalates). Extrinsic and intrinsic labeling techniques gave a similar assessment of calcium bioavailability from kale but not from spinach

  3. Calcium and Nuclear Signaling in Prostate Cancer

    Ivan V. Maly; Wilma A. Hofmann

    2018-01-01

    Recently, there have been a number of developments in the fields of calcium and nuclear signaling that point to new avenues for a more effective diagnosis and treatment of prostate cancer. An example is the discovery of new classes of molecules involved in calcium-regulated nuclear import and nuclear calcium signaling, from the G protein-coupled receptor (GPCR) and myosin families. This review surveys the new state of the calcium and nuclear signaling fields with the aim of identifying the un...

  4. 21 CFR 184.1195 - Calcium citrate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium citrate. 184.1195 Section 184.1195 Food and... Substances Affirmed as GRAS § 184.1195 Calcium citrate. (a) Calcium citrate (Ca3(C6H5O7)2·4H2O, CAS Reg. No. 813-0994-095) is the calcium salt of citric acid. It is prepared by neutralizing citric acid with...

  5. 21 CFR 184.1185 - Calcium acetate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may be...

  6. 21 CFR 184.1229 - Calcium stearate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium stearate. 184.1229 Section 184.1229 Food... Specific Substances Affirmed as GRAS § 184.1229 Calcium stearate. (a) Calcium stearate (Ca(C17H35COO)2, CAS Reg. No. 1529-23-0) is the calcium salt of stearic acid derived from edible sources. It is prepared as...

  7. Calcium Balance in Chronic Kidney Disease.

    Hill Gallant, Kathleen M; Spiegel, David M

    2017-06-01

    The kidneys play a critical role in the balance between the internal milieu and external environment. Kidney failure is known to disrupt a number of homeostatic mechanisms that control serum calcium and normal bone metabolism. However, our understanding of calcium balance throughout the stages of chronic kidney disease is limited and the concept of balance itself, especially with a cation as complex as calcium, is often misunderstood. Both negative and positive calcium balance have important implications in patients with chronic kidney disease, where negative balance may increase risk of osteoporosis and fracture and positive balance may increase risk of vascular calcification and cardiovascular events. Here, we examine the state of current knowledge about calcium balance in adults throughout the stages of chronic kidney disease and discuss recommendations for clinical strategies to maintain balance as well as future research needs in this area. Recent calcium balance studies in adult patients with chronic kidney disease show that neutral calcium balance is achieved with calcium intake near the recommended daily allowance. Increases in calcium through diet or supplements cause high positive calcium balance, which may put patients at risk for vascular calcification. However, heterogeneity in calcium balance exists among these patients. Given the available calcium balance data in this population, it appears clinically prudent to aim for recommended calcium intakes around 1000 mg/day to achieve neutral calcium balance and avoid adverse effects of either negative or positive calcium balance. Assessment of patients' dietary calcium intake could further equip clinicians to make individualized recommendations for meeting recommended intakes.

  8. 21 CFR 184.1193 - Calcium chloride.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium chloride. 184.1193 Section 184.1193 Food... Specific Substances Affirmed as GRAS § 184.1193 Calcium chloride. (a) Calcium chloride (CaCl2·2H2O, CAS Reg. No. 10035-04-8) or anhydrous calcium chloride (CaCl2, CAS Reg. No. 10043-52-4) may be commercially...

  9. The Electronic Structure of Calcium

    Jan, J.-P.; Skriver, Hans Lomholt

    1981-01-01

    The electronic structure of calcium under pressure is re-examined by means of self-consistent energy band calculations based on the local density approximation and using the linear muffin-tin orbitals (LMTO) method with corrections to the atomic sphere approximation included. At zero pressure...

  10. The impact of calcium assay change on a local adjusted calcium equation.

    Davies, Sarah L; Hill, Charlotte; Bailey, Lisa M; Davison, Andrew S; Milan, Anna M

    2016-03-01

    Deriving and validating local adjusted calcium equations is important for ensuring appropriate calcium status classification. We investigated the impact on our local adjusted calcium equation of a change in calcium method by the manufacturer from cresolphthalein complexone to NM-BAPTA. Calcium and albumin results from general practice requests were extracted from the Laboratory Information Management system for a three-month period. Results for which there was evidence of disturbance in calcium homeostasis were excluded leaving 13,482 sets of results for analysis. The adjusted calcium equation was derived following least squares regression analysis of total calcium on albumin and normalized to the mean calcium concentration of the data-set. The revised equation (NM-BAPTA calcium method) was compared with the previous equation (cresolphthalein complexone calcium method). The switch in calcium assay resulted in a small change in the adjusted calcium equation but was not considered to be clinically significant. The calcium reference interval differed from that proposed by Pathology Harmony in the UK. Local adjusted calcium equations should be re-assessed following changes in the calcium method. A locally derived reference interval may differ from the consensus harmonized reference interval. © The Author(s) 2015.

  11. Genome-wide comparative analysis of NBS-encoding genes between Brassica species and Arabidopsis thaliana.

    Yu, Jingyin; Tehrim, Sadia; Zhang, Fengqi; Tong, Chaobo; Huang, Junyan; Cheng, Xiaohui; Dong, Caihua; Zhou, Yanqiu; Qin, Rui; Hua, Wei; Liu, Shengyi

    2014-01-03

    triplication analysis in B. oleracea, B. rapa and A. thaliana genomes, our study provides insight into the evolutionary history of NBS-encoding genes after divergence of A. thaliana and the Brassica lineage. These results together with expression pattern analysis of NBS-encoding orthologous genes provide useful resource for functional characterization of these genes and genetic improvement of relevant crops.

  12. Absorbability of calcium from calcium-bound phosphoryl oligosaccharides in comparison with that from various calcium compounds in the rat ligated jejunum loop.

    To-o, Kenji; Kamasaka, Hiroshi; Nishimura, Takahisa; Kuriki, Takashi; Saeki, Shigeru; Nakabou, Yukihiro

    2003-08-01

    Calcium-bound phosphoryl oligosaccharides (POs-Ca) were prepared from potato starch. Their solubility and in situ absorbability as a calcium source were investigated by comparing with the soluble calcium compounds, calcium chloride and calcium lactate, or insoluble calcium compounds, calcium carbonate and dibasic calcium phosphate. The solubility of POs-Ca was as high as that of calcium chloride and about 3-fold higher than that of calcium lactate. An in situ experiment showed that the intestinal calcium absorption rate of POs-Ca was almost comparable with that of the soluble calcium compounds, and was significantly higher (pcalcium groups. Moreover, the total absorption rate of a 1:1 mixture of the calcium from POs-Ca and a whey mineral complex (WMC) was significantly higher (psoluble calcium source with relatively high absorption in the intestinal tract.

  13. 21 CFR 582.1210 - Calcium oxide.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium oxide. 582.1210 Section 582.1210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1210 Calcium oxide. (a) Product. Calcium oxide. (b) Conditions of use. This substance is generally...

  14. 21 CFR 582.5210 - Calcium oxide.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium oxide. 582.5210 Section 582.5210 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS... 1 § 582.5210 Calcium oxide. (a) Product. Calcium oxide. (b) Conditions of use. This substance is...

  15. Lactulose stimulates calcium absorption in postmenopausal women

    Heuvel, E.G.H.M. van den; Muijs, T.; Dokkum, W. van; Schaafsma, G.

    1999-01-01

    Animal studies have indicated that calcium absorption is increased by lactulose, a synthetic disaccharide. Therefore, the influence of lactulose on calcium absorption was measured in postmenopausal women who may benefit from the possible enhancing effect of lactulose on calcium absorption. Twelve

  16. 21 CFR 182.3225 - Calcium sorbate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium sorbate. 182.3225 Section 182.3225 Food and... CONSUMPTION (CONTINUED) SUBSTANCES GENERALLY RECOGNIZED AS SAFE Chemical Preservatives § 182.3225 Calcium sorbate. (a) Product. Calcium sorbate. (b) Conditions of use. This substance is generally recognized as...

  17. 21 CFR 582.5230 - Calcium sulfate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sulfate. 582.5230 Section 582.5230 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5230 Calcium sulfate. (a) Product. Calcium sulfate. (b) Conditions of use. This substance...

  18. 21 CFR 582.6185 - Calcium acetate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium acetate. 582.6185 Section 582.6185 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium acetate. (a) Product. Calcium acetate. (b) Conditions of use. This substance is generally...

  19. 21 CFR 582.5195 - Calcium citrate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.5195 Section 582.5195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Supplements 1 § 582.5195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance...

  20. 21 CFR 582.3225 - Calcium sorbate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium sorbate. 582.3225 Section 582.3225 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL....3225 Calcium sorbate. (a) Product. Calcium sorbate. (b) Conditions of use. This substance is generally...

  1. 21 CFR 582.6195 - Calcium citrate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.6195 Section 582.6195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is generally...

  2. 21 CFR 582.6219 - Calcium phytate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium phytate. 582.6219 Section 582.6219 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium phytate. (a) Product. Calcium phytate. (b) Conditions of use. This substance is generally...

  3. 21 CFR 582.1207 - Calcium lactate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium lactate. 582.1207 Section 582.1207 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1207 Calcium lactate. (a) Product. Calcium lactate. (b) Conditions of use. This substance is...

  4. 21 CFR 182.2227 - Calcium silicate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium silicate. 182.2227 Section 182.2227 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR... Calcium silicate. (a) Product. Calcium silicate. (b) Tolerance. 2 percent and 5 percent. (c) Limitations...

  5. 21 CFR 582.1195 - Calcium citrate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium citrate. 582.1195 Section 582.1195 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1195 Calcium citrate. (a) Product. Calcium citrate. (b) Conditions of use. This substance is...

  6. 21 CFR 582.7187 - Calcium alginate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium alginate. 582.7187 Section 582.7187 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium alginate. (a) Product. Calcium alginate. (b) Conditions of use. This substance is generally...

  7. 21 CFR 582.2227 - Calcium silicate.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium silicate. 582.2227 Section 582.2227 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium silicate. (a) Product. Calcium silicate. (b) Tolerance. 2 percent and 5 percent. (c) Limitations...

  8. Mechanism of store-operated calcium entry

    Activation of receptors coupled to the phospholipase C/IP3 signalling pathway results in a rapid release of calcium from its intracellular stores, eventually leading to depletion of these stores. Calcium store depletion triggers an influx of extracellular calcium across the plasma membrane, a mechanism known as the ...

  9. 21 CFR 201.70 - Calcium labeling.

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Calcium labeling. 201.70 Section 201.70 Food and... LABELING Labeling Requirements for Over-the-Counter Drugs § 201.70 Calcium labeling. (a) The labeling of over-the-counter (OTC) drug products intended for oral ingestion shall contain the calcium content per...

  10. Preparation and properties of calcium zirconate

    Dudek, M.; Bucko, M.; Rog, G.

    2001-01-01

    Dense samples of calcium zirconate were prepared. Electrical conductivity of the samples were measured in the temperature range 873 - 1273 K by both the d.c. four probe and the impedance spectroscopy methods. Calcium zirconate with small excess of calcium oxide appeared to be oxygen ion conductor. It was applied as an electrolyte in solid-state galvanic cells. (author)

  11. Calcium dynamics in vascular smooth muscle

    Amberg, Gregory C.; Navedo, Manuel F.

    2013-01-01

    Smooth muscle cells are ultimately responsible for determining vascular luminal diameter and blood flow. Dynamic changes in intracellular calcium are a critical mechanism regulating vascular smooth muscle contractility. Processes influencing intracellular calcium are therefore important regulators of vascular function with physiological and pathophysiological consequences. In this review we discuss the major dynamic calcium signals identified and characterized in vascular smooth muscle cells....

  12. 21 CFR 582.6193 - Calcium chloride.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium chloride. 582.6193 Section 582.6193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance is generally...

  13. 21 CFR 582.1193 - Calcium chloride.

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Calcium chloride. 582.1193 Section 582.1193 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL... Additives § 582.1193 Calcium chloride. (a) Product. Calcium chloride. (b) Conditions of use. This substance...

  14. 7 CFR 58.434 - Calcium chloride.

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Calcium chloride. 58.434 Section 58.434 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Material § 58.434 Calcium chloride. Calcium chloride, when used, shall meet the requirements of the Food...

  15. Genetic Causes of Rickets

    Acar, Sezer; Demir, Korcan; Shi, Yufei

    2017-01-01

    Rickets is a metabolic bone disease that develops as a result of inadequate mineralization of growing bone due to disruption of calcium, phosphorus and/or vitamin D metabolism. Nutritional rickets remains a significant child health problem in developing countries. In addition, several rare genetic causes of rickets have also been described, which can be divided into two groups. The first group consists of genetic disorders of vitamin D biosynthesis and action, such as vitamin D-dependent rickets type 1A (VDDR1A), vitamin D-dependent rickets type 1B (VDDR1B), vitamin D-dependent rickets type 2A (VDDR2A), and vitamin D-dependent rickets type 2B (VDDR2B). The second group involves genetic disorders of excessive renal phosphate loss (hereditary hypophosphatemic rickets) due to impairment in renal tubular phosphate reabsorption as a result of FGF23-related or FGF23-independent causes. In this review, we focus on clinical, laboratory and genetic characteristics of various types of hereditary rickets as well as differential diagnosis and treatment approaches. PMID:29280738

  16. Cloud-based uniform ChIP-Seq processing tools for modENCODE and ENCODE.

    Trinh, Quang M; Jen, Fei-Yang Arthur; Zhou, Ziru; Chu, Kar Ming; Perry, Marc D; Kephart, Ellen T; Contrino, Sergio; Ruzanov, Peter; Stein, Lincoln D

    2013-07-22

    Funded by the National Institutes of Health (NIH), the aim of the Model Organism ENCyclopedia of DNA Elements (modENCODE) project is to provide the biological research community with a comprehensive encyclopedia of functional genomic elements for both model organisms C. elegans (worm) and D. melanogaster (fly). With a total size of just under 10 terabytes of data collected and released to the public, one of the challenges faced by researchers is to extract biologically meaningful knowledge from this large data set. While the basic quality control, pre-processing, and analysis of the data has already been performed by members of the modENCODE consortium, many researchers will wish to reinterpret the data set using modifications and enhancements of the original protocols, or combine modENCODE data with other data sets. Unfortunately this can be a time consuming and logistically challenging proposition. In recognition of this challenge, the modENCODE DCC has released uniform computing resources for analyzing modENCODE data on Galaxy (https://github.com/modENCODE-DCC/Galaxy), on the public Amazon Cloud (http://aws.amazon.com), and on the private Bionimbus Cloud for genomic research (http://www.bionimbus.org). In particular, we have released Galaxy workflows for interpreting ChIP-seq data which use the same quality control (QC) and peak calling standards adopted by the modENCODE and ENCODE communities. For convenience of use, we have created Amazon and Bionimbus Cloud machine images containing Galaxy along with all the modENCODE data, software and other dependencies. Using these resources provides a framework for running consistent and reproducible analyses on modENCODE data, ultimately allowing researchers to use more of their time using modENCODE data, and less time moving it around.

  17. Interactions between calcium and phosphorus in the regulation of the production of fibroblast growth factor 23 in vivo

    Quinn, Stephen J.; Thomsen, Alex R. B.; Pang, Jian L.; Kantham, Lakshmi; Bräuner-Osborne, Hans; Pollak, Martin; Goltzman, David

    2013-01-01

    Calcium and phosphorus homeostasis are highly interrelated and share common regulatory hormones, including FGF23. However, little is known about calcium's role in the regulation of FGF23. We sought to investigate the regulatory roles of calcium and phosphorus in FGF23 production using genetic mouse models with targeted inactivation of PTH (PTH KO) or both PTH and the calcium-sensing receptor (CaSR; PTH-CaSR DKO). In wild-type, PTH KO, and PTH-CaSR DKO mice, elevation of either serum calcium or phosphorus by intraperitoneal injection increased serum FGF23 levels. In PTH KO and PTH-CaSR DKO mice, however, increases in serum phosphorus by dietary manipulation were accompanied by severe hypocalcemia, which appeared to blunt stimulation of FGF23 release. Increases in dietary phosphorus in PTH-CaSR DKO mice markedly decreased serum 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] despite no change in FGF23, suggesting direct regulation of 1,25(OH)2D3 synthesis by serum phosphorus. Calcium-mediated increases in serum FGF23 required a threshold level of serum phosphorus of about 5 mg/dl. Analogously, phosphorus-elicited increases in FGF23 were markedly blunted if serum calcium was less than 8 mg/dl. The best correlation between calcium and phosphorus and serum FGF23 was found between FGF23 and the calcium × phosphorus product. Since calcium stimulated FGF23 production in the PTH-CaSR DKO mice, this effect cannot be mediated by the full-length CaSR. Thus the regulation of FGF23 by both calcium and phosphorus appears to be fundamentally important in coordinating the serum levels of both mineral ions and ensuring that the calcium × phosphorus product remains within a physiological range. PMID:23233539

  18. Effect of anions or foods on absolute bioavailability of calcium from calcium salts in mice by pharmacokinetics

    Zenei Taira, Zenei; Ueda,Yukari

    2013-01-01

    Yukari Ueda, Zenei TairaFaculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, JapanAbstract: We studied the absolute bioavailability of calcium from calcium L-lactate in mice using pharmacokinetics, and reviewed the absolute bioavailability of calcium from three other calcium salts in mice previously studied: calcium chloride, calcium acetate, and calcium ascorbate. The results showed that calcium metabolism is linear between intravenous administration of 15 mg/kg and 30 ...

  19. Noise level and MPEG-2 encoder statistics

    Lee, Jungwoo

    1997-01-01

    Most software in the movie and broadcasting industries are still in analog film or tape format, which typically contains random noise that originated from film, CCD camera, and tape recording. The performance of the MPEG-2 encoder may be significantly degraded by the noise. It is also affected by the scene type that includes spatial and temporal activity. The statistical property of noise originating from camera and tape player is analyzed and the models for the two types of noise are developed. The relationship between the noise, the scene type, and encoder statistics of a number of MPEG-2 parameters such as motion vector magnitude, prediction error, and quant scale are discussed. This analysis is intended to be a tool for designing robust MPEG encoding algorithms such as preprocessing and rate control.

  20. Indirect Encoding in Neuroevolutionary Ship Handling

    Miroslaw Lacki

    2018-03-01

    Full Text Available In this paper the author compares the efficiency of two encoding schemes for artificial intelligence methods used in the neuroevolutionary ship maneuvering system. This may be also be seen as the ship handling system that simulates a learning process of a group of artificial helmsmen - autonomous control units, created with an artificial neural network. The helmsman observes input signals derived form an enfironment and calculates the values of required parameters of the vessel maneuvering in confined waters. In neuroevolution such units are treated as individuals in population of artificial neural networks, which through environmental sensing and evolutionary algorithms learn to perform given task efficiently. The main task of this project is to evolve a population of helmsmen with indirect encoding and compare results of simulation with direct encoding method.

  1. An Information Theoretic Characterisation of Auditory Encoding

    Overath, Tobias; Cusack, Rhodri; Kumar, Sukhbinder; von Kriegstein, Katharina; Warren, Jason D; Grube, Manon; Carlyon, Robert P; Griffiths, Timothy D

    2007-01-01

    The entropy metric derived from information theory provides a means to quantify the amount of information transmitted in acoustic streams like speech or music. By systematically varying the entropy of pitch sequences, we sought brain areas where neural activity and energetic demands increase as a function of entropy. Such a relationship is predicted to occur in an efficient encoding mechanism that uses less computational resource when less information is present in the signal: we specifically tested the hypothesis that such a relationship is present in the planum temporale (PT). In two convergent functional MRI studies, we demonstrated this relationship in PT for encoding, while furthermore showing that a distributed fronto-parietal network for retrieval of acoustic information is independent of entropy. The results establish PT as an efficient neural engine that demands less computational resource to encode redundant signals than those with high information content. PMID:17958472

  2. Radioisotope 45Ca labeling four calcium chemical compounds and tracing calcium bioavailability

    Zheng Hui; Zhen Rong; Niu Huisheng; Li Huaifen

    2004-01-01

    Objective: To build up a new method of the radioisotope 45 Ca labeling four calcium chemical compounds, observe and tracing bioavailability change of calcium labeled with radioisotope 45 Ca. Methods: The calcium gluconate (Ca-Glu), calcium citrate (Ca-Cit), calcium carbonate (Ca-Car) and calcium L-threonate (Ca-Thr)were labeled by radioisotope 45 Ca. Four calcium chemical compounds of 45 Ca labeling were used of calcium content 200 mg/kg in the rats and measure the absorption content and bioavailability of calcium in tissue of heart, lever spleen, stomach, kidney, brain, intestine, whole blood, urine, faeces. Results: 1) Radioisotope 45 Ca labeling calcium chemical compound has high radio intensity, more steady standard curve and recover rate. 2) The absorption of organic calcium chemical compounds is higher than the inorganic calcium chemical compound in the study of calcium bioavailability. Conclusion: The method of tracing with radioisotope 45 Ca labeling calcium chemical compounds has the characteristic of the sensitive, objective, accurate and steady in the study of calcium bioavailability

  3. Incremental phonological encoding during unscripted sentence production

    Florian T Jaeger

    2012-11-01

    Full Text Available We investigate phonological encoding during unscripted sentence production, focusing on the effect of phonological overlap on phonological encoding. Previous work on this question has almost exclusively employed isolated word production or highly scripted multiword production. These studies have led to conflicting results: some studies found that phonological overlap between two words facilitates phonological encoding, while others found inhibitory effects. One worry with many of these paradigms is that they involve processes that are not typical to everyday language use, which calls into question to what extent their findings speak to the architectures and mechanisms underlying language production. We present a paradigm to investigate the consequences of phonological overlap between words in a sentence while leaving speakers much of the lexical and structural choices typical in everyday language use. Adult native speakers of English described events in short video clips. We annotated the presence of disfluencies and the speech rate at various points throughout the sentence, as well as the constituent order. We find that phonological overlap has an inhibitory effect on phonological encoding. Specifically, if adjacent content words share their phonological onset (e.g., hand the hammer, they are preceded by production difficulty, as reflected in fluency and speech rate. We also find that this production difficulty affects speakers’ constituent order preferences during grammatical encoding. We discuss our results and previous works to isolate the properties of other paradigms that resulted in facilitatory or inhibitory results. The data from our paradigm also speak to questions about the scope of phonological planning in unscripted speech and as to whether phonological and grammatical encoding interact.

  4. Optical encoder based on a nondiffractive beam

    Lutenberg, Ariel; Perez-Quintian, Fernando; Rebollo, Maria A.

    2008-01-01

    Optical encoders are used in industrial and laboratory motion equipment to measure rotations and linear displacements. We introduce a design of an optical encoder based on a nondiffractive beam. We expect that the invariant profile and radial symmetry of the nondiffractive beam provide the design with remarkable tolerance to mechanical perturbations. We experimentally demonstrate that the proposed design generates a suitable output sinusoidal signal with low harmonic distortion. Moreover, we present a numerical model of the system based on the angular spectrum approximation whose predictions are in excellent agreement with the experimental results

  5. Calcium regulation and Alzheimer’s disease

    Deepthi Rapaka

    2014-09-01

    Full Text Available Activation of the neuron induces transient fluctuations in [Ca2+]i. This transient rise in [Ca2+]i is dependent on calcium entry via calcium channels and release of calcium from intracellular stores, finally resulting in increase in calcium levels, which activates calcium regulatory proteins to restore the resting calcium levels by binding to the calcium-binding proteins, sequestration into the endoplasmic reticulum and the mitochondria, and finally extrusion of calcium spike potential from the cell by adenosine triphosphate-driven Ca2+ pumps and the Na+/Ca2+ exchanger. Improper regulation of calcium signaling, sequentially, likely contributes to synaptic dysfunction and excitotoxic and/or apoptotic death of the vulnerable neuronal populations. The cognitive decline associated with normal aging is not only due to neuronal loss, but is fairly the result of synaptic connectivity. Many evidences support that Ca2+ dyshomeostasis is implicated in normal brain aging. Thus the chief factor associated with Alzheimer’s disease was found to be increase in the levels of free intracellular calcium, demonstrating that the excessive levels might lead to cell death, which provides a key target for the calcium channel blockers might be used as the neuroprotective agents in Alzheimer’s disease.

  6. Presynaptic calcium signalling in cerebellar mossy fibres

    Thomsen, Louiza Bohn; Jörntell, Henrik; Midtgaard, Jens

    2010-01-01

    Whole-cell recordings were obtained from mossy fibre terminals in adult turtles in order to characterize the basic membrane properties. Calcium imaging of presynaptic calcium signals was carried out in order to analyse calcium dynamics and presynaptic GABA B inhibition. A tetrodotoxin (TTX......)-sensitive fast Na(+) spike faithfully followed repetitive depolarizing pulses with little change in spike duration or amplitude, while a strong outward rectification dominated responses to long-lasting depolarizations. High-threshold calcium spikes were uncovered following addition of potassium channel blockers....... Calcium imaging using Calcium-Green dextran revealed a stimulus-evoked all-or-none TTX-sensitive calcium signal in simple and complex rosettes. All compartments of a complex rosette were activated during electrical activation of the mossy fibre, while individual simple and complex rosettes along an axon...

  7. Seasonal Variations in Mercury's Dayside Calcium Exosphere

    Burger, Matthew H.; Killen, Rosemary M.; McClintock, William E.; Merkel, Aimee W.; Vervack, Ronald J., Jr.; Cassidy, Timothy A.; Sarantos, Menelaos

    2014-01-01

    The Mercury Atmospheric and Surface Composition Spectrometer on the MESSENGER spacecraft has observed calcium emission in Mercury's exosphere on a near-daily basis since March 2011. During MESSENGER's primary and first extended missions (March 2011 - March 2013) the dayside calcium exosphere was measured over eight Mercury years. We have simulated these data with a Monte Carlo model of exospheric source processes to show that (a) there is a persistent source of energetic calcium located in the dawn equatorial region, (b) there is a seasonal dependence in the calcium source rate, and (c) there are no obvious year-to-year variations in the near-surface dayside calcium exosphere. Although the precise mechanism responsible for ejecting the calcium has not yet been determined, the most likely process is the dissociation of Ca-bearing molecules produced in micrometeoroid impact plumes to form energetic, escaping calcium atoms.

  8. Intracellular sphingosine releases calcium from lysosomes.

    Höglinger, Doris; Haberkant, Per; Aguilera-Romero, Auxiliadora; Riezman, Howard; Porter, Forbes D; Platt, Frances M; Galione, Antony; Schultz, Carsten

    2015-11-27

    To elucidate new functions of sphingosine (Sph), we demonstrate that the spontaneous elevation of intracellular Sph levels via caged Sph leads to a significant and transient calcium release from acidic stores that is independent of sphingosine 1-phosphate, extracellular and ER calcium levels. This photo-induced Sph-driven calcium release requires the two-pore channel 1 (TPC1) residing on endosomes and lysosomes. Further, uncaging of Sph leads to the translocation of the autophagy-relevant transcription factor EB (TFEB) to the nucleus specifically after lysosomal calcium release. We confirm that Sph accumulates in late endosomes and lysosomes of cells derived from Niemann-Pick disease type C (NPC) patients and demonstrate a greatly reduced calcium release upon Sph uncaging. We conclude that sphingosine is a positive regulator of calcium release from acidic stores and that understanding the interplay between Sph homeostasis, calcium signaling and autophagy will be crucial in developing new therapies for lipid storage disorders such as NPC.

  9. Genetic variation in KCNA5

    Christophersen, Ingrid E; Olesen, Morten S; Liang, Bo

    2012-01-01

    AimsGenetic factors may be important in the development of atrial fibrillation (AF) in the young. KCNA5 encodes the potassium channel a-subunit K(V)1.5, which underlies the voltage-gated atrial-specific potassium current I(Kur). KCNAB2 encodes K(V)ß2, a ß-subunit of K(V)1.5, which increases I......(Kur). Three studies have identified loss-of-function mutations in KCNA5 in patients with idiopathic AF. We hypothesized that early-onset lone AF is associated with high prevalence of genetic variants in KCNA5 and KCNAB2.Methods and resultsThe coding sequences of KCNA5 and KCNAB2 were sequenced in 307 patients...

  10. Exopolysaccharides regulate calcium flow in cariogenic biofilms

    Varenganayil, Muth M.; Decho, Alan W.

    2017-01-01

    Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS) provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya’s agar. Calcium tolerance was assessed by isothermal microcalorimetry (IMC) by adding CaCl2 to the bacterial cultures. Acid-base titration and Fourier transform infrared (FTIR) spectroscopy were used to identify possible functional groups responsible for calcium binding, which was assessed by isothermal titration calorimetry (ITC). Lactobacillus spp. and mutans streptococci demonstrated calcium dissolution in the presence of different carbohydrates. All strains that demonstrated high dissolution rates also revealed higher rates of calcium tolerance by IMC. In addition, acidic functional groups were predominantly identified as possible binding sites for calcium ions by acid-base titration and FTIR. Finally, ITC revealed EPS to have a higher binding affinity for calcium compared, for example, to lactic acid. In conclusion, this study illustrates the role of EPS in terms of the calcium tolerance of cariogenic microbiota by determining the ability of EPS to control free calcium concentrations within the biofilms as a self-regulating mode of action in the pathogenesis of dental caries. PMID:29023506

  11. Exopolysaccharides regulate calcium flow in cariogenic biofilms.

    Monika Astasov-Frauenhoffer

    Full Text Available Caries-associated biofilms induce loss of calcium from tooth surfaces in the presence of dietary carbohydrates. Exopolysaccharides (EPS provide a matrix scaffold and an abundance of primary binding sites within biofilms. The role of EPS in binding calcium in cariogenic biofilms is only partially understood. Thus, the aim of the present study is to investigate the relationship between the calcium dissolution rates and calcium tolerance of caries-associated bacteria and yeast as well as to examine the properties of EPS to quantify its binding affinity for dissolved calcium. Calcium dissolution was measured by dissolution zones on Pikovskaya's agar. Calcium tolerance was assessed by isothermal microcalorimetry (IMC by adding CaCl2 to the bacterial cultures. Acid-base titration and Fourier transform infrared (FTIR spectroscopy were used to identify possible functional groups responsible for calcium binding, which was assessed by isothermal titration calorimetry (ITC. Lactobacillus spp. and mutans streptococci demonstrated calcium dissolution in the presence of different carbohydrates. All strains that demonstrated high dissolution rates also revealed higher rates of calcium tolerance by IMC. In addition, acidic functional groups were predominantly identified as possible binding sites for calcium ions by acid-base titration and FTIR. Finally, ITC revealed EPS to have a higher binding affinity for calcium compared, for example, to lactic acid. In conclusion, this study illustrates the role of EPS in terms of the calcium tolerance of cariogenic microbiota by determining the ability of EPS to control free calcium concentrations within the biofilms as a self-regulating mode of action in the pathogenesis of dental caries.

  12. Monitoring changes in genetic diversity

    Bruford, MW

    2018-01-01

    Full Text Available has thrived in many different environments over the billions of years, encoding its solutions into DNA—the heredity material. Thanks to this genetic patrimony, many species are equipped with sufficient evolutionary resi- lience to overcome rapid... for food, shelter, medicines, fuel and ecotourism income but may also include those that are ecologically important providing other key ecosystem services such as 120 M.W. Bruford et al. pollination, nutrient cycling and pest regulation (Bailey 2011...

  13. Trafficking of neuronal calcium channels

    Weiss, Norbert; Zamponi, G. W.

    2017-01-01

    Roč. 1, č. 1 (2017), č. článku NS20160003. ISSN 2059-6553 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : calcium channel * neuron * trafficing Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) http://www.neuronalsignaling.org/content/1/1/NS20160003

  14. Surfactant Protein-D-Encoding Gene Variant Polymorphisms Are Linked to Respiratory Outcome in Premature Infants

    Sorensen, Grith Lykke; Dahl, Marianne; Tan, Qihua

    2014-01-01

    OBJECTIVE: Associations between the genetic variation within or downstream of the surfactant protein-D-encoding gene (SFTPD), which encodes the collectin surfactant protein-D (SP-D) and may lead to respiratory distress syndrome or bronchopulmonary dysplasia, recently were reported. Our aim...... were used to associate genetic variation to SP-D, respiratory distress (RD), oxygen requirement, and respiratory support. RESULTS: The 5'-upstream SFTPD SNP rs1923534 and the 3 structural SNPs rs721917, rs2243639, and rs3088308 were associated with the SP-D level. The same SNPs were associated with RD......, a requirement for supplemental oxygen, and a requirement for respiratory support. Haplotype analyses identified 3 haplotypes that included the minor alleles of rs1923534, rs721917, and rs3088308 that exhibited highly significant associations with decreased SP-D levels and decreased ORs for RD, oxygen...

  15. Constraining Calcium Production in Novae

    Tiwari, Pranjal; C. Fry, C. Wrede Team; A. Chen, J. Liang Collaboration; S. Bishop, T. Faestermann, D. Seiler Collaboration; R. Hertenberger, H. Wirth Collaboration

    2017-09-01

    Calcium is an element that can be produced by thermonuclear reactions in the hottest classical novae. There are discrepancies between the abundance of Calcium observed in novae and expectations based on astrophysical models. Unbound states 1 MeV above the proton threshold affect the production of Calcium in nova models because they act as resonances in the 38 K(p , γ) 39 Ca reaction present. This work describes an experiment to measure the energies of the excited states of 39 Ca . We will bombard a thin target of 40 Ca with a beam of 22 MeV deuterons, resulting in tritons and 39Ca. We will use a Q3D magnetic spectrograph from the MLL in Garching, Germany to momenta analyze the tritons to observe the excitation energies of the resulting 39 Ca states. Simulations have been run to determine the optimal spectrograph settings. We decided to use a chemically stable target composed of CaF2 , doing so resulted in an extra contaminant, Fluorine, which is dealt with by measuring the background from a LiF target. These simulations have led to settings and targets that will result in the observation of the 39 Ca states of interest with minimal interference from contaminants. Preliminary results from this experiment will be presented. National Sciences and Engineering Research Council of Canada and U.S. National Science Foundation.

  16. Enhanced immunogenicity of DNA fusion vaccine encoding secreted hepatitis B surface antigen and chemokine RANTES

    Kim, Seung Jo; Suh, Dongchul; Park, Sang Eun; Park, Jeong-Sook; Byun, Hyang-Min; Lee, Chan; Lee, Sun Young; Kim, Inho; Oh, Yu-Kyoung

    2003-01-01

    To increase the potency of DNA vaccines, we constructed genetic fusion vaccines encoding antigen, secretion signal, and/or chemokine RANTES. The DNA vaccines encoding secreted hepatitis B surface antigen (HBsAg) were constructed by inserting HBsAg gene into an expression vector with an endoplasmic reticulum (ER)-targeting secretory signal sequence. The plasmid encoding secretory HBsAg (pER/HBs) was fused to cDNA of RANTES, generating pER/HBs/R. For comparison, HBsAg genes were cloned into pVAX1 vector with no signal sequence (pHBs), and further linked to the N-terminus of RANTES (pHBs/R). Immunofluorescence study showed the cytoplasmic localization of HBsAg protein expressed from pHBs and pHBs/R, but not from pER/HBs and pER/HBs/R at 48 h after transfection. In mice, RANTES-fused DNA vaccines more effectively elicited the levels of HBsAg-specific IgG antibodies than pHBs. All the DNA vaccines induced higher levels of IgG 2a rather than IgG 1 antibodies. Of RANTES-fused vaccines, pER/HBs/R encoding the secreted fusion protein revealed much higher humoral and CD8 + T cell-stimulating responses compared to pHBs/R. These results suggest that the immunogenicity of DNA vaccines could be enhanced by genetic fusion to a secretory signal peptide sequence and RANTES

  17. RNAi suppressors encoded by pathogenic human viruses

    de Vries, Walter; Berkhout, Ben

    2008-01-01

    RNA silencing or RNAi interference (RNAi) serves as an innate antiviral mechanism in plants, fungi and animals. Human viruses, like plant viruses, encode suppressor proteins or RNAs that block or modulate the RNAi pathway. This review summarizes the mechanisms by which pathogenic human viruses

  18. Visual Memory : The Price of Encoding Details

    Nieuwenstein, Mark; Kromm, Maria

    2017-01-01

    Studies on visual long-term memory have shown that we have a tremendous capacity for remembering pictures of objects, even at a highly detailed level. What remains unclear, however, is whether encoding objects at such a detailed level comes at any cost. In the current study, we examined how the

  19. Encoders for block-circulant LDPC codes

    Divsalar, Dariush (Inventor); Abbasfar, Aliazam (Inventor); Jones, Christopher R. (Inventor); Dolinar, Samuel J. (Inventor); Thorpe, Jeremy C. (Inventor); Andrews, Kenneth S. (Inventor); Yao, Kung (Inventor)

    2009-01-01

    Methods and apparatus to encode message input symbols in accordance with an accumulate-repeat-accumulate code with repetition three or four are disclosed. Block circulant matrices are used. A first method and apparatus make use of the block-circulant structure of the parity check matrix. A second method and apparatus use block-circulant generator matrices.

  20. 47 CFR 11.32 - EAS Encoder.

    2010-10-01

    ... Telecommunication FEDERAL COMMUNICATIONS COMMISSION GENERAL EMERGENCY ALERT SYSTEM (EAS) Equipment Requirements § 11... operation. (vi) Indicator Display. The encoder shall be provided with a visual and/or aural indicator which... to +50 degrees C and a range of relative humidity of up to 95%. (c) Primary Supply Voltage Variation...

  1. Toward Chemical Implementation of Encoded Combinatorial Libraries

    Nielsen, John; Janda, Kim D.

    1994-01-01

    The recent application of "combinatorial libraries" to supplement existing drug screening processes might simplify and accelerate the search for new lead compounds or drugs. Recently, a scheme for encoded combinatorial chemistry was put forward to surmount a number of the limitations possessed...

  2. Pharmacological modulation of mitochondrial calcium homeostasis.

    Arduino, Daniela M; Perocchi, Fabiana

    2018-01-10

    Mitochondria are pivotal organelles in calcium (Ca 2+ ) handling and signalling, constituting intracellular checkpoints for numerous processes that are vital for cell life. Alterations in mitochondrial Ca 2+ homeostasis have been linked to a variety of pathological conditions and are critical in the aetiology of several human diseases. Efforts have been taken to harness mitochondrial Ca 2+ transport mechanisms for therapeutic intervention, but pharmacological compounds that direct and selectively modulate mitochondrial Ca 2+ homeostasis are currently lacking. New avenues have, however, emerged with the breakthrough discoveries on the genetic identification of the main players involved in mitochondrial Ca 2+ influx and efflux pathways and with recent hints towards a deep understanding of the function of these molecular systems. Here, we review the current advances in the understanding of the mechanisms and regulation of mitochondrial Ca 2+ homeostasis and its contribution to physiology and human disease. We also introduce and comment on the recent progress towards a systems-level pharmacological targeting of mitochondrial Ca 2+ homeostasis. © 2018 The Authors. The Journal of Physiology © 2018 The Physiological Society.

  3. Mitochondrially-Encoded Adenosine Triphosphate Synthase 6 Gene Haplotype Variation among World Population during 2003-2013

    Steven Steven; Yoni F Syukriani; Julius B Dewanto

    2016-01-01

    Background: Adaptation and natural selection serve as an important part of evolution. Adaptation in molecular level can lead to genetic drift which causes mutation of genetic material; one of which is polymorphism of mitochondrial DNA (mtDNA). The aim of this study is to verify the polymorphism of mitochondrially-encoded Adenosine Triphosphate synthase6gene (MT-ATP6) as one of mtDNA building blocks among tropic, sub-tropic, and polar areas. Methods: This descriptive quantitative research used...

  4. Expression of genes encoding multi-transmembrane proteins in specific primate taste cell populations.

    Bryan D Moyer

    Full Text Available BACKGROUND: Using fungiform (FG and circumvallate (CV taste buds isolated by laser capture microdissection and analyzed using gene arrays, we previously constructed a comprehensive database of gene expression in primates, which revealed over 2,300 taste bud-associated genes. Bioinformatics analyses identified hundreds of genes predicted to encode multi-transmembrane domain proteins with no previous association with taste function. A first step in elucidating the roles these gene products play in gustation is to identify the specific taste cell types in which they are expressed. METHODOLOGY/PRINCIPAL FINDINGS: Using double label in situ hybridization analyses, we identified seven new genes expressed in specific taste cell types, including sweet, bitter, and umami cells (TRPM5-positive, sour cells (PKD2L1-positive, as well as other taste cell populations. Transmembrane protein 44 (TMEM44, a protein with seven predicted transmembrane domains with no homology to GPCRs, is expressed in a TRPM5-negative and PKD2L1-negative population that is enriched in the bottom portion of taste buds and may represent developmentally immature taste cells. Calcium homeostasis modulator 1 (CALHM1, a component of a novel calcium channel, along with family members CALHM2 and CALHM3; multiple C2 domains; transmembrane 1 (MCTP1, a calcium-binding transmembrane protein; and anoctamin 7 (ANO7, a member of the recently identified calcium-gated chloride channel family, are all expressed in TRPM5 cells. These proteins may modulate and effect calcium signalling stemming from sweet, bitter, and umami receptor activation. Synaptic vesicle glycoprotein 2B (SV2B, a regulator of synaptic vesicle exocytosis, is expressed in PKD2L1 cells, suggesting that this taste cell population transmits tastant information to gustatory afferent nerve fibers via exocytic neurotransmitter release. CONCLUSIONS/SIGNIFICANCE: Identification of genes encoding multi-transmembrane domain proteins

  5. Calcium Unresponsive Hypocalcemic Tetany: Gitelman Syndrome with Hypocalcemia

    Madhav Desai

    2013-01-01

    Full Text Available Introduction. Gitelman’s syndrome (GS is autosomal recessive renal tubular disorder characterized by hypokalemia, hypomagnesemia, hypocalciuria, metabolic alkalosis, and hyperreninemic hyperaldosteronism. It is usually associated with normal serum calcium. We report a patient presented with hypocalcemic tetany, and evaluation showed Gitelman’s syndrome with hypocalcemia. Case Report. A 28-year-old woman presented with cramps of the arms, legs, fatigue, and carpal spasms of one week duration. She has history of similar episodes on and off for the past two years. Her blood pressure was 98/66 mmHg. Chvostek’s sign and Trousseau’s sign were positive. Evaluation showed hypokalemia, hypocalcemia, hypomagnesemia, metabolic alkalosis, and hypocalciuria. Self-medication, diuretic use, laxative abuse, persistent vomiting, and diarrhoea were ruled out. Urinary prostaglandins and genetic testing could not be done because of nonavailability. To differentiate Gitelman syndrome from Bartter’s syndrome (BS, thiazide loading test was done. It showed blunted fractional chloride excretion. GS was confirmed and patient was treated with spironolactone along with magnesium, calcium, and potassium supplementation. Symptomatically, she improved and did not develop episodes of tetany again. Conclusion. In tetany patient along with serum calcium measurement, serum magnesium, serum potassium, and arterial blood gases should be measured. Even though hypocalcemia in Gitelman syndrome is rare, it still can occur.

  6. Natural products induce a G protein-mediated calcium pathway activating p53 in cancer cells

    Ginkel, Paul R. van; Yan, Michael B. [UW Carbone Cancer Center, University of Wisconsin, Madison, WI 53792 (United States); Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI 53792 (United States); Bhattacharya, Saswati [UW Carbone Cancer Center, University of Wisconsin, Madison, WI 53792 (United States); Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI 53792 (United States); Department of Pediatrics, University of Wisconsin, Madison, WI 53792 (United States); Polans, Arthur S., E-mail: aspolans@wisc.edu [UW Carbone Cancer Center, University of Wisconsin, Madison, WI 53792 (United States); Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI 53792 (United States); Kenealey, Jason D. [UW Carbone Cancer Center, University of Wisconsin, Madison, WI 53792 (United States); Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, WI 53792 (United States); Department of Nutrition, Dietetics and Food Science, Brigham Young University, Provo, UT 84602 (United States)

    2015-11-01

    Paclitaxel, etoposide, vincristine and doxorubicin are examples of natural products being used as chemotherapeutics but with adverse side effects that limit their therapeutic window. Natural products derived from plants and having low toxicity, such as quercetin, resveratrol, epigallocatechin gallate and piceatannol, have been shown to inhibit tumor cell growth both in vitro and in pre-clinical models of cancer, but their mechanisms of action have not been fully elucidated, thus restricting their use as prototypes for developing synthetic analogs with improved anti-cancer properties. We and others have demonstrated that one of the earliest and consistent events upon exposure of tumor cells to these less toxic natural products is a rise in cytoplasmic calcium, activating several pro-apoptotic pathways. We describe here a G protein/inositol 1,4,5-trisphosphate pathway (InsP3) in MDA-MB-231 human breast cancer cells that mediates between these less toxic natural products and the release of calcium from the endoplasmic reticulum. Further, we demonstrate that this elevation of intracellular calcium modulates p53 activity and the subsequent transcription of several pro-apoptotic genes encoding PIG8, CD95, PIDD, TP53INP, RRM2B, Noxa, p21 and PUMA. We conclude from our findings that less toxic natural products likely bind to a G protein coupled receptor that activates a G protein-mediated and calcium-dependent pathway resulting selectively in tumor cell death. - Highlights: • Natural products having low toxicity increase cytoplasmic calcium in cancer cells. • A G-protein/IP{sub 3} pathway mediates the release of calcium from the ER. • The elevation of intracellular calcium modulates p53 activity. • p53 and other Ca{sup 2+}-dependent pro-apoptotic pathways inhibit cancer cell growth.

  7. Natural products induce a G protein-mediated calcium pathway activating p53 in cancer cells

    Ginkel, Paul R. van; Yan, Michael B.; Bhattacharya, Saswati; Polans, Arthur S.; Kenealey, Jason D.

    2015-01-01

    Paclitaxel, etoposide, vincristine and doxorubicin are examples of natural products being used as chemotherapeutics but with adverse side effects that limit their therapeutic window. Natural products derived from plants and having low toxicity, such as quercetin, resveratrol, epigallocatechin gallate and piceatannol, have been shown to inhibit tumor cell growth both in vitro and in pre-clinical models of cancer, but their mechanisms of action have not been fully elucidated, thus restricting their use as prototypes for developing synthetic analogs with improved anti-cancer properties. We and others have demonstrated that one of the earliest and consistent events upon exposure of tumor cells to these less toxic natural products is a rise in cytoplasmic calcium, activating several pro-apoptotic pathways. We describe here a G protein/inositol 1,4,5-trisphosphate pathway (InsP3) in MDA-MB-231 human breast cancer cells that mediates between these less toxic natural products and the release of calcium from the endoplasmic reticulum. Further, we demonstrate that this elevation of intracellular calcium modulates p53 activity and the subsequent transcription of several pro-apoptotic genes encoding PIG8, CD95, PIDD, TP53INP, RRM2B, Noxa, p21 and PUMA. We conclude from our findings that less toxic natural products likely bind to a G protein coupled receptor that activates a G protein-mediated and calcium-dependent pathway resulting selectively in tumor cell death. - Highlights: • Natural products having low toxicity increase cytoplasmic calcium in cancer cells. • A G-protein/IP 3 pathway mediates the release of calcium from the ER. • The elevation of intracellular calcium modulates p53 activity. • p53 and other Ca 2+ -dependent pro-apoptotic pathways inhibit cancer cell growth.

  8. Genetic modification and genetic determinism

    Resnik, David B; Vorhaus, Daniel B

    2006-01-01

    In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions. PMID:16800884

  9. Rapid screening assay for calcium bioavailability studies

    Luhrsen, K.R.; Hudepohl, G.R.; Smith, K.T.

    1986-01-01

    Calcium bioavailability has been studied by numerous techniques. The authors report here the use of the gamma emitting isotope of calcium ( 47 Ca) in a whole body retention assay system. In this system, calcium sources are administered by oral gavage and subsequent counts are determined and corrected for isotopic decay. Unlike iron and zinc retention curves, which exhibit a 2-3 day equilibration period, calcium reaches equilibration after 24 hours. Autoradiographic analysis of the femurs indicate that the newly absorbed calcium is rapidly distributed to the skeletal system. Moreover, the isotope is distributed along the entire bone. Comparisons of calcium bioavailability were made using intrinsic/extrinsic labeled milk from two species i.e. rat and goat as well as CaCO 3 . In addition, extrinsic labeled cow milk was examined. In the rat, the extrinsic labeled calcium from milk was better absorbed than the intrinsic calcium. This was not the case in goat milk or the calcium carbonate which exhibited no significant differences. Chromatographic analysis of the labeled milk indicates a difference in distribution of the 47 Ca. From these data, the authors recommend the use of this assay system in calcium bioavailability studies. The labeling studies and comparisons indicate caution should be used, however, in labeling techniques and species milk comparison

  10. The Role of Calcium in Osteoporosis

    Arnaud, C. D.; Sanchez, S. D.

    1991-01-01

    Calcium requirements may vary throughout the lifespan. During the growth years and up to age 25 to 30, it is important to maximize dietary intake of calcium to maintain positive calcium balance and achieve peak bone mass, thereby possibly decreasing the risk of fracture when bone is subsequently lost. Calcium intake need not be greater than 800 mg/day during the relatively short period of time between the end of bone building and the onset of bone loss (30 to 40 years). Starting at age 40 to 50, both men and women lose bone slowly, but women lose bone more rapidly around the menopause and for about 10 years after. Intestinal calcium absorption and the ability to adapt to low calcium diets are impaired in many postmenopausal women and elderly persons owing to a suspected functional or absolute decrease in the ability of the kidney to produce 1,25(OH)2D2. The bones then become more and more a source of calcium to maintain critical extracellular fluid calcium levels. Excessive dietary intake of protein and fiber may induce significant negative calcium balance and thus increase dietary calcium requirements. Generally, the strongest risk factors for osteoporosis are uncontrollable (e.g., sex, age, and race) or less controllable (e.g., disease and medications). However, several factors such as diet, physical activity, cigarette smoking, and alcohol use are lifestyle related and can be modified to help reduce the risk of osteoporosis.

  11. The Risks and Benefits of Calcium Supplementation

    Chan Soo Shin

    2015-03-01

    Full Text Available The association between calcium supplementation and adverse cardiovascular events has recently become a topic of debate due to the publication of two epidemiological studies and one meta-analysis of randomized controlled clinical trials. The reports indicate that there is a significant increase in adverse cardiovascular events following supplementation with calcium; however, a number of experts have raised several issues with these reports such as inconsistencies in attempts to reproduce the findings in other populations and questions concerning the validity of the data due to low compliance, biases in case ascertainment, and/or a lack of adjustment. Additionally, the Auckland Calcium Study, the Women's Health Initiative, and many other studies included in the meta-analysis obtained data from calcium-replete subjects and it is not clear whether the same risk profile would be observed in populations with low calcium intakes. Dietary calcium intake varies widely throughout the world and it is especially low in East Asia, although the risk of cardiovascular events is less prominent in this region. Therefore, clarification is necessary regarding the occurrence of adverse cardiovascular events following calcium supplementation and whether this relationship can be generalized to populations with low calcium intakes. Additionally, the skeletal benefits from calcium supplementation are greater in subjects with low calcium intakes and, therefore, the risk-benefit ratio of calcium supplementation is likely to differ based on the dietary calcium intake and risks of osteoporosis and cardiovascular diseases of various populations. Further studies investigating the risk-benefit profiles of calcium supplementation in various populations are required to develop population-specific guidelines for individuals of different genders, ages, ethnicities, and risk profiles around the world.

  12. Pareto-optimal multi-objective dimensionality reduction deep auto-encoder for mammography classification.

    Taghanaki, Saeid Asgari; Kawahara, Jeremy; Miles, Brandon; Hamarneh, Ghassan

    2017-07-01

    Feature reduction is an essential stage in computer aided breast cancer diagnosis systems. Multilayer neural networks can be trained to extract relevant features by encoding high-dimensional data into low-dimensional codes. Optimizing traditional auto-encoders works well only if the initial weights are close to a proper solution. They are also trained to only reduce the mean squared reconstruction error (MRE) between the encoder inputs and the decoder outputs, but do not address the classification error. The goal of the current work is to test the hypothesis that extending traditional auto-encoders (which only minimize reconstruction error) to multi-objective optimization for finding Pareto-optimal solutions provides more discriminative features that will improve classification performance when compared to single-objective and other multi-objective approaches (i.e. scalarized and sequential). In this paper, we introduce a novel multi-objective optimization of deep auto-encoder networks, in which the auto-encoder optimizes two objectives: MRE and mean classification error (MCE) for Pareto-optimal solutions, rather than just MRE. These two objectives are optimized simultaneously by a non-dominated sorting genetic algorithm. We tested our method on 949 X-ray mammograms categorized into 12 classes. The results show that the features identified by the proposed algorithm allow a classification accuracy of up to 98.45%, demonstrating favourable accuracy over the results of state-of-the-art methods reported in the literature. We conclude that adding the classification objective to the traditional auto-encoder objective and optimizing for finding Pareto-optimal solutions, using evolutionary multi-objective optimization, results in producing more discriminative features. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Adaptations in Maternofetal Calcium Transport in Relation to Placental Size and Fetal Sex in Mice

    Christina E. Hayward

    2017-12-01

    Full Text Available Appropriate placental transport of calcium is essential for normal fetal skeletal mineralization. In fetal growth restriction (FGR, the failure of a fetus to achieve its growth potential, a number of placental nutrient transport systems show reduced activity but, in the case of calcium, placental transport is increased. In a genetic mouse model of FGR this increase, or adaptation, maintains appropriate fetal calcium content, relative to the size of the fetus, despite a small, dysfunctional placenta. It is unknown whether such an adaptation is also apparent in small, but normally functioning placentas. We tested the hypothesis that calcium transfer would be up-regulated in the lightest vs. heaviest placentas in the same C57Bl/6J wild-type (WT mouse litter. Since lightest placentas are often from females, we also assessed whether fetal sex influenced placental calcium transfer. Placentas and fetuses were collected at embryonic day (E16.5 and 18.5; the lightest and heaviest placentas, and female and male fetuses, were identified. Unidirectional maternofetal calcium clearance (CaKmf was assessed following 45Ca administration to the dam and subsequent radiolabel counts within the fetuses. Placental expression of calcium pathway components was measured by Western blot. Data (median are lightest placenta expressed as percentage of the heaviest within a litter and analyzed by Wilcoxon signed-rank test. In WT mice having normally grown fetuses, CaKmf, per gram placenta near term, in the lightest placentas was increased (126%; P < 0.05 in association with reduced fetal calcium accretion earlier in gestation (92%; P < 0.05, that was subsequently normalized near term. Increased placental expression of calbindin-D9K, an important calcium binding protein, was observed in the lightest placentas near term (122%; P < 0.01. There was no difference in fetal calcium accretion between male and female littermates but a trend toward higher CaKmf in females (P = 0

  14. Calcium signals can freely cross the nuclear envelope in hippocampal neurons: somatic calcium increases generate nuclear calcium transients

    Bading Hilmar

    2007-07-01

    Full Text Available Abstract Background In hippocampal neurons, nuclear calcium signaling is important for learning- and neuronal survival-associated gene expression. However, it is unknown whether calcium signals generated by neuronal activity at the cell membrane and propagated to the soma can unrestrictedly cross the nuclear envelope to invade the nucleus. The nuclear envelope, which allows ion transit via the nuclear pore complex, may represent a barrier for calcium and has been suggested to insulate the nucleus from activity-induced cytoplasmic calcium transients in some cell types. Results Using laser-assisted uncaging of caged calcium compounds in defined sub-cellular domains, we show here that the nuclear compartment border does not represent a barrier for calcium signals in hippocampal neurons. Although passive diffusion of molecules between the cytosol and the nucleoplasm may be modulated through changes in conformational state of the nuclear pore complex, we found no evidence for a gating mechanism for calcium movement across the nuclear border. Conclusion Thus, the nuclear envelope does not spatially restrict calcium transients to the somatic cytosol but allows calcium signals to freely enter the cell nucleus to trigger genomic events.

  15. From Genetics to Genetic Algorithms

    Genetic algorithms (GAs) are computational optimisation schemes with an ... The algorithms solve optimisation problems ..... Genetic Algorithms in Search, Optimisation and Machine. Learning, Addison-Wesley Publishing Company, Inc. 1989.

  16. From Genetics to Genetic Algorithms

    artificial genetic system) string feature or ... called the genotype whereas it is called a structure in artificial genetic ... assigned a fitness value based on the cost function. Better ..... way it has produced complex, intelligent living organisms capable of ...

  17. Mouse Y-Encoded Transcription Factor Zfy2 Is Essential for Sperm Head Remodelling and Sperm Tail Development

    Vernet, Nadege; Mahadevaiah, Shantha K.; Decarpentrie, Fanny; Longepied, Guy; de Rooij, Dirk G.; Burgoyne, Paul S.; Mitchell, Michael J.

    2016-01-01

    A previous study indicated that genetic information encoded on the mouse Y chromosome short arm (Yp) is required for efficient completion of the second meiotic division (that generates haploid round spermatids), restructuring of the sperm head, and development of the sperm tail. Using mouse models

  18. A Single Nucleotide Polymorphism (rs4236480 in TRPV5 Calcium Channel Gene Is Associated with Stone Multiplicity in Calcium Nephrolithiasis Patients

    Anas Khaleel

    2015-01-01

    Full Text Available Nephrolithiasis is characterized by calcification of stones in the kidneys from an unknown cause. Animal models demonstrated the functional roles of the transient receptor potential vanilloid member 5 (TRPV5 gene in calcium renal reabsorption and hypercalciuria. Therefore, TRPV5 was suggested to be involved in calcium homeostasis. However, whether genetic polymorphisms of TRPV5 are associated with kidney stone multiplicity or recurrence is unclear. In this study, 365 Taiwanese kidney-stone patients were recruited. Both biochemical data and DNA samples were collected. Genotyping was performed by a TaqMan allelic discrimination assay. We found that a TRPV5 polymorphism (rs4236480 was observed to be associated with stone multiplicity of calcium nephrolithiasis, as the risk of stone multiplicity was higher in patients with the TT+CT genotype than in patients with the CC genotype (p=0.0271. In summary, despite the complexity of nephrolithiasis and the potential association of numerous calcium homeostatic absorption/reabsorption factors, TRPV5 plays an important role in the pathogenesis of calcium nephrolithiasis.

  19. About Genetic Counselors

    ... clinical care in many areas of medicine. Assisted Reproductive Technology/Infertility Genetics Cancer Genetics Cardiovascular Genetics Cystic Fibrosis Genetics Fetal Intervention and Therapy Genetics Hematology Genetics Metabolic Genetics ...

  20. Brain calcium - Role in temperature regulation.

    Hanegan, J. L.; Williams, B. A.

    1973-01-01

    Perfusion of the preoptic-anterior hypothalamus with excess calcium ion in ground squirrels produces a drop in core temperature. The magnitude of the drop is directly dependent on ambient temperature. Respiration, heart rate, and oxygen consumption are also reduced during perfusion of calcium ion. It is concluded that the depression of body temperature during calcium ion perfusion is due to generalized depression of the neurons of the preoptic-anterior hypothalamus.

  1. Familial hypocalciuric hypercalcemia and calcium sensing receptor

    Mrgan, Monija; Nielsen, Sanne; Brixen, Kim

    2014-01-01

    Familial hypocalciuric hypercalcemia (FHH) is a lifelong, benign autosomal dominant disease characterized by hypercalcemia, normal to increased parathyroid hormone level, and a relatively low renal calcium excretion. Inactivation of the calcium-sensing receptor in heterozygous patients results...... in FHH, while in homozygous patients as well as in compound heterozygous or dominant negative heterozygous patients, it may result in neonatal severe hyperparathyroidism (NSHPT). Parathyroid surgery is not indicated in FHH and does not lower plasma calcium unless total parathyroidectomy is performed...

  2. The total synthesis of calcium atorvastatin.

    Dias, Luiz C; Vieira, Adriano S; Barreiro, Eliezer J

    2016-02-21

    A practical and convergent asymmetric route to calcium atorvastatin (1) is reported. The synthesis of calcium atorvastatin (1) was performed using the remote 1,5-anti asymmetric induction in the boron-mediated aldol reaction of β-alkoxy methylketone (4) with pyrrolic aldehyde (3) as a key step. Calcium atorvastatin was obtained from aldehyde (3) after 6 steps, with a 41% overall yield.

  3. 21 CFR 184.1206 - Calcium iodate.

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium iodate. 184.1206 Section 184.1206 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN... Substances Affirmed as GRAS § 184.1206 Calcium iodate. (a) Calcium iodate [Ca(IO3)2·H2O, CAS Reg. No. 7789-80...

  4. An Intensional Concurrent Faithful Encoding of Turing Machines

    Thomas Given-Wilson

    2014-10-01

    Full Text Available The benchmark for computation is typically given as Turing computability; the ability for a computation to be performed by a Turing Machine. Many languages exploit (indirect encodings of Turing Machines to demonstrate their ability to support arbitrary computation. However, these encodings are usually by simulating the entire Turing Machine within the language, or by encoding a language that does an encoding or simulation itself. This second category is typical for process calculi that show an encoding of lambda-calculus (often with restrictions that in turn simulates a Turing Machine. Such approaches lead to indirect encodings of Turing Machines that are complex, unclear, and only weakly equivalent after computation. This paper presents an approach to encoding Turing Machines into intensional process calculi that is faithful, reduction preserving, and structurally equivalent. The encoding is demonstrated in a simple asymmetric concurrent pattern calculus before generalised to simplify infinite terms, and to show encodings into Concurrent Pattern Calculus and Psi Calculi.

  5. Calcium hydroxide isotope effect in calcium isotope enrichment by ion exchange

    Jepson, B.E.; Shockey, G.C.

    1984-01-01

    The enrichment of calcium isotopes has been observed in ion-exchange chromatography with an aqueous phase of calcium hydroxide and a solid phase of sulfonic acid resin. The band front was exceedingly sharp as a result of the acid-base reaction occuring at the front of the band. Single-stage separation coefficients were found to be epsilon( 44 Ca/ 40 Ca) = 11 x 10 -4 and epsilon( 48 Ca/ 40 Ca) = 18 x 10 -4 . The maximum column separation factors achieved were 1.05 for calcium-44 and 1.09 for calcium-48 with the heavy isotopes enriching in the fluid phase. The calcium isotope effect between fully hydrated aqueous calcium ions and undissociated aqueous calcium hydroxide was estimated. For the calcium-44/40 isotope pair the separation coefficient was 13 x 10 -4 . 20 references, 2 figures

  6. Calcium isotope fractionation between soft and mineralized tissues as a monitor of calcium use in vertebrates

    Skulan, Joseph; DePaolo, Donald J.

    1999-01-01

    Calcium from bone and shell is isotopically lighter than calcium of soft tissue from the same organism and isotopically lighter than source (dietary) calcium. When measured as the 44Ca/40Ca isotopic ratio, the total range of variation observed is 5.5‰, and as much as 4‰ variation is found in a single organism. The observed intraorganismal calcium isotopic variations and the isotopic differences between tissues and diet indicate that isotopic fractionation occurs mainly as a result of mineralization. Soft tissue calcium becomes heavier or lighter than source calcium during periods when there is net gain or loss of mineral mass, respectively. These results suggest that variations of natural calcium isotope ratios in tissues may be useful for assessing the calcium and mineral balance of organisms without introducing isotopic tracers. PMID:10570137

  7. Temporal information encoding in dynamic memristive devices

    Ma, Wen; Chen, Lin; Du, Chao; Lu, Wei D., E-mail: wluee@eecs.umich.edu [Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, Michigan 48109 (United States)

    2015-11-09

    We show temporal and frequency information can be effectively encoded in memristive devices with inherent short-term dynamics. Ag/Ag{sub 2}S/Pd based memristive devices with low programming voltage (∼100 mV) were fabricated and tested. At weak programming conditions, the devices exhibit inherent decay due to spontaneous diffusion of the Ag atoms. When the devices were subjected to pulse train inputs emulating different spiking patterns, the switching probability distribution function diverges from the standard Poisson distribution and evolves according to the input pattern. The experimentally observed switching probability distributions and the associated cumulative probability functions can be well-explained using a model accounting for the short-term decay effects. Such devices offer an intriguing opportunity to directly encode neural signals for neural information storage and analysis.

  8. DNA-Encoded Dynamic Combinatorial Chemical Libraries.

    Reddavide, Francesco V; Lin, Weilin; Lehnert, Sarah; Zhang, Yixin

    2015-06-26

    Dynamic combinatorial chemistry (DCC) explores the thermodynamic equilibrium of reversible reactions. Its application in the discovery of protein binders is largely limited by difficulties in the analysis of complex reaction mixtures. DNA-encoded chemical library (DECL) technology allows the selection of binders from a mixture of up to billions of different compounds; however, experimental results often show low a signal-to-noise ratio and poor correlation between enrichment factor and binding affinity. Herein we describe the design and application of DNA-encoded dynamic combinatorial chemical libraries (EDCCLs). Our experiments have shown that the EDCCL approach can be used not only to convert monovalent binders into high-affinity bivalent binders, but also to cause remarkably enhanced enrichment of potent bivalent binders by driving their in situ synthesis. We also demonstrate the application of EDCCLs in DNA-templated chemical reactions. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Storing data encoded DNA in living organisms

    Wong,; Pak C. , Wong; Kwong K. , Foote; Harlan, P [Richland, WA

    2006-06-06

    Current technologies allow the generation of artificial DNA molecules and/or the ability to alter the DNA sequences of existing DNA molecules. With a careful coding scheme and arrangement, it is possible to encode important information as an artificial DNA strand and store it in a living host safely and permanently. This inventive technology can be used to identify origins and protect R&D investments. It can also be used in environmental research to track generations of organisms and observe the ecological impact of pollutants. Today, there are microorganisms that can survive under extreme conditions. As well, it is advantageous to consider multicellular organisms as hosts for stored information. These living organisms can provide as memory housing and protection for stored data or information. The present invention provides well for data storage in a living organism wherein at least one DNA sequence is encoded to represent data and incorporated into a living organism.

  10. Bacillus caldolyticus prs gene encoding phosphoribosyldiphosphate synthase

    Krath, Britta N.; Hove-Jensen, Bjarne

    1996-01-01

    The prs gene, encoding phosphoribosyl-diphosphate (PRPP) synthase, as well as the flanking DNA sequences were cloned and sequenced from the Gram-positive thermophile, Bacillus caldolyticus. Comparison with the homologous sequences from the mesophile, Bacillus subtilis, revealed a gene (gca......D) encoding N-acetylglucosamine-l-phosphate uridyltransferase upstream of prs, and a gene homologous to ctc downstream of prs. cDNA synthesis with a B. caldolyticus gcaD-prs-ctc-specified mRNA as template, followed by amplification utilising the polymerase chain reaction indicated that the three genes are co......-transcribed. Comparison of amino acid sequences revealed a high similarity among PRPP synthases across a wide phylogenetic range. An E. coli strain harbouring the B. caldolyticus prs gene in a multicopy plasmid produced PRPP synthase activity 33-fold over the activity of a haploid B. caldolyticus strain. B. caldolyticus...

  11. Nucleic acid compositions and the encoding proteins

    Preston, III, James F.; Chow, Virginia; Nong, Guang; Rice, John D.; St. John, Franz J.

    2014-09-02

    The subject invention provides at least one nucleic acid sequence encoding an aldouronate-utilization regulon isolated from Paenibacillus sp. strain JDR-2, a bacterium which efficiently utilizes xylan and metabolizes aldouronates (methylglucuronoxylosaccharides). The subject invention also provides a means for providing a coordinately regulated process in which xylan depolymerization and product assimilation are coupled in Paenibacillus sp. strain JDR-2 to provide a favorable system for the conversion of lignocellulosic biomass to biobased products. Additionally, the nucleic acid sequences encoding the aldouronate-utilization regulon can be used to transform other bacteria to form organisms capable of producing a desired product (e.g., ethanol, 1-butanol, acetoin, 2,3-butanediol, 1,3-propanediol, succinate, lactate, acetate, malate or alanine) from lignocellulosic biomass.

  12. Asymmetric synthesis using chiral-encoded metal

    Yutthalekha, Thittaya; Wattanakit, Chularat; Lapeyre, Veronique; Nokbin, Somkiat; Warakulwit, Chompunuch; Limtrakul, Jumras; Kuhn, Alexander

    2016-08-01

    The synthesis of chiral compounds is of crucial importance in many areas of society and science, including medicine, biology, chemistry, biotechnology and agriculture. Thus, there is a fundamental interest in developing new approaches for the selective production of enantiomers. Here we report the use of mesoporous metal structures with encoded geometric chiral information for inducing asymmetry in the electrochemical synthesis of mandelic acid as a model molecule. The chiral-encoded mesoporous metal, obtained by the electrochemical reduction of platinum salts in the presence of a liquid crystal phase and the chiral template molecule, perfectly retains the chiral information after removal of the template. Starting from a prochiral compound we demonstrate enantiomeric excess of the (R)-enantiomer when using (R)-imprinted electrodes and vice versa for the (S)-imprinted ones. Moreover, changing the amount of chiral cavities in the material allows tuning the enantioselectivity.

  13. Calcium and magnesium silicate hydrates

    Lothenbach, B.; L'Hopital, E.; Nied, D.; Achiedo, G.; Dauzeres, A.

    2015-01-01

    Deep geological disposals are planed to discard long-lived intermediate-level and high-level radioactive wastes. Clay-based geological barriers are expected to limit the ingress of groundwater and to reduce the mobility of radioelements. In the interaction zone between the cement and the clay based material alteration can occur. Magnesium silicate hydrates (M-S-H) have been observed due to the reaction of magnesium sulfate containing groundwater with cements or in the interaction zone between low-pH type cement and clays. M-S-H samples synthesized in the laboratory showed that M-S-H has a variable composition within 0.7 ≤ Mg/Si ≤ 1.5. TEM/EDS analyses show an homogeneous gel with no defined structure. IR and 29 Si NMR data reveal a higher polymerization degree of the silica network in M-S-H compared to calcium silicate hydrates (C-S-H). The presence of mainly Q 3 silicate tetrahedrons in M-S-H indicates a sheet like or a triple-chain silica structure while C-S-H is characterised by single chain-structure. The clear difference in the silica structure and the larger ionic radius of Ca 2+ (1.1 Angstrom) compared to Mg 2+ (0.8 Angstrom) make the formation of an extended solid solution between M-S-H and C-S-H gel improbable. In fact, the analyses of synthetic samples containing both magnesium and calcium in various ratios indicate the formation of separate M-S-H and C-S-H gels with no or very little uptake of magnesium in CS-H or calcium in M-S-H

  14. PKA controls calcium influx into motor neurons during a rhythmic behavior.

    Han Wang

    Full Text Available Cyclic adenosine monophosphate (cAMP has been implicated in the execution of diverse rhythmic behaviors, but how cAMP functions in neurons to generate behavioral outputs remains unclear. During the defecation motor program in C. elegans, a peptide released from the pacemaker (the intestine rhythmically excites the GABAergic neurons that control enteric muscle contractions by activating a G protein-coupled receptor (GPCR signaling pathway that is dependent on cAMP. Here, we show that the C. elegans PKA catalytic subunit, KIN-1, is the sole cAMP target in this pathway and that PKA is essential for enteric muscle contractions. Genetic analysis using cell-specific expression of dominant negative or constitutively active PKA transgenes reveals that knockdown of PKA activity in the GABAergic neurons blocks enteric muscle contractions, whereas constitutive PKA activation restores enteric muscle contractions to mutants defective in the peptidergic signaling pathway. Using real-time, in vivo calcium imaging, we find that PKA activity in the GABAergic neurons is essential for the generation of synaptic calcium transients that drive GABA release. In addition, constitutively active PKA increases the duration of calcium transients and causes ectopic calcium transients that can trigger out-of-phase enteric muscle contractions. Finally, we show that the voltage-gated calcium channels UNC-2 and EGL-19, but not CCA-1 function downstream of PKA to promote enteric muscle contractions and rhythmic calcium influx in the GABAergic neurons. Thus, our results suggest that PKA activates neurons during a rhythmic behavior by promoting presynaptic calcium influx through specific voltage-gated calcium channels.

  15. PKA Controls Calcium Influx into Motor Neurons during a Rhythmic Behavior

    Wang, Han; Sieburth, Derek

    2013-01-01

    Cyclic adenosine monophosphate (cAMP) has been implicated in the execution of diverse rhythmic behaviors, but how cAMP functions in neurons to generate behavioral outputs remains unclear. During the defecation motor program in C. elegans, a peptide released from the pacemaker (the intestine) rhythmically excites the GABAergic neurons that control enteric muscle contractions by activating a G protein-coupled receptor (GPCR) signaling pathway that is dependent on cAMP. Here, we show that the C. elegans PKA catalytic subunit, KIN-1, is the sole cAMP target in this pathway and that PKA is essential for enteric muscle contractions. Genetic analysis using cell-specific expression of dominant negative or constitutively active PKA transgenes reveals that knockdown of PKA activity in the GABAergic neurons blocks enteric muscle contractions, whereas constitutive PKA activation restores enteric muscle contractions to mutants defective in the peptidergic signaling pathway. Using real-time, in vivo calcium imaging, we find that PKA activity in the GABAergic neurons is essential for the generation of synaptic calcium transients that drive GABA release. In addition, constitutively active PKA increases the duration of calcium transients and causes ectopic calcium transients that can trigger out-of-phase enteric muscle contractions. Finally, we show that the voltage-gated calcium channels UNC-2 and EGL-19, but not CCA-1 function downstream of PKA to promote enteric muscle contractions and rhythmic calcium influx in the GABAergic neurons. Thus, our results suggest that PKA activates neurons during a rhythmic behavior by promoting presynaptic calcium influx through specific voltage-gated calcium channels. PMID:24086161

  16. Optimal Achievable Encoding for Brain Machine Interface

    2017-12-22

    dictionary-based encoding approach to translate a visual image into sequential patterns of electrical stimulation in real time , in a manner that...including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and...networks, and by applying linear decoding to complete recorded populations of retinal ganglion cells for the first time . Third, we developed a greedy

  17. Calcium carboorthovanadate - a new compound with the apa

    Slobodin, B.V.; Dmitrieva, O.I.; Fotiev, A.A.

    1977-01-01

    Data on calcium carboorthovanadate, Ca 10 (VO 4 ) 6 CO 3 , a new compound with an appatite structure based on calcium orthovanadate, are reported. The synthesis has been conducted in a stoichiometric mixture of finely ground calcium carbonate and calcium orthovanadate. It is found that calcium carboorthovanadate belongs to the hexagonal syngony and has an apatite structure. An analysis of the infrared spectra of initial compounds and calcium carboorthovanadate confirmed the presence of carbonate (CO 3 ) 2- and orthovanadate (VO 4 ) 3 groupings in the latter. On heating in air, beginning with 450 deg C calcium carboorthovanadate decomposes at a slow rate into calcium oxide, calcium orthovanadate, and carbon dioxide

  18. Regulation of cardiomyocyte autophagy by calcium.

    Shaikh, Soni; Troncoso, Rodrigo; Criollo, Alfredo; Bravo-Sagua, Roberto; García, Lorena; Morselli, Eugenia; Cifuentes, Mariana; Quest, Andrew F G; Hill, Joseph A; Lavandero, Sergio

    2016-04-15

    Calcium signaling plays a crucial role in a multitude of events within the cardiomyocyte, including cell cycle control, growth, apoptosis, and autophagy. With respect to calcium-dependent regulation of autophagy, ion channels and exchangers, receptors, and intracellular mediators play fundamental roles. In this review, we discuss calcium-dependent regulation of cardiomyocyte autophagy, a lysosomal mechanism that is often cytoprotective, serving to defend against disease-related stress and nutrient insufficiency. We also highlight the importance of the subcellular distribution of calcium and related proteins, interorganelle communication, and other key signaling events that govern cardiomyocyte autophagy. Copyright © 2016 the American Physiological Society.

  19. How calcium makes endocytic receptors attractive

    Andersen, Christian B F; Moestrup, Søren K

    2014-01-01

    of the receptor. Endosomal acidification and calcium efflux lead to the essential ligand-receptor affinity switch and separation. Recent data, including crystal structures of receptor-ligand complexes, now reveal how calcium, in different types of domain scaffolds, functions in a common way as a removable...... 'lynchpin' that stabilizes favorable positioning of ligand-attractive receptor residues. In addition to explaining how calcium depletion can cause ligand-receptor dissociation, the new data add further insight into how acidification contributes to dissociation through structural changes that affect...... the receptor calcium sites....

  20. Diuretics and disorders of calcium homeostasis.

    Grieff, Marvin; Bushinsky, David A

    2011-11-01

    Diuretics commonly are administered in disorders of sodium balance. Loop diuretics inhibit the Na-K-2Cl transporter and also increase calcium excretion. They are often used in the treatment of hypercalcemia. Thiazide diuretics block the thiazide-sensitive NaCl transporter in the distal convoluted tubule, and can decrease calcium excretion. They are often used in the treatment of nephrolithiasis. Carbonic anhydrase inhibitors decrease bicarbonate absorption and the resultant metabolic acidosis can increase calcium excretion. Their use can promote nephrocalcinosis and nephrolithiasis. This review will address the use of diuretics on disorders of calcium homeostasis. Copyright © 2011 Elsevier Inc. All rights reserved.

  1. Role of polyhydroxybutyrate in mitochondrial calcium uptake

    Smithen, Matthew; Elustondo, Pia A.; Winkfein, Robert; Zakharian, Eleonora; Abramov, Andrey Y.; Pavlov, Evgeny

    2013-01-01

    Polyhydroxybutyrate (PHB) is a biological polymer which belongs to the class of polyesters and is ubiquitously present in all living organisms. Mammalian mitochondrial membranes contain PHB consisting of up to 120 hydroxybutyrate residues. Roles played by PHB in mammalian mitochondria remain obscure. It was previously demonstrated that PHB of the size similar to one found in mitochondria mediates calcium transport in lipid bilayer membranes. We hypothesized that the presence of PHB in mitochondrial membrane might play a significant role in mitochondrial calcium transport. To test this, we investigated how the induction of PHB hydrolysis affects mitochondrial calcium transport. Mitochondrial PHB was altered enzymatically by targeted expression of bacterial PHB hydrolyzing enzyme (PhaZ7) in mitochondria of mammalian cultured cells. The expression of PhaZ7 induced changes in mitochondrial metabolism resulting in decreased mitochondrial membrane potential in HepG2 but not in U87 and HeLa cells. Furthermore, it significantly inhibited mitochondrial calcium uptake in intact HepG2, U87 and HeLa cells stimulated by the ATP or by the application of increased concentrations of calcium to the digitonin permeabilized cells. Calcium uptake in PhaZ7 expressing cells was restored by mimicking calcium uniporter properties with natural electrogenic calcium ionophore - ferutinin. We propose that PHB is a previously unrecognized important component of the mitochondrial calcium uptake system. PMID:23702223

  2. Trace mineral interactions during elevated calcium consumption

    Smith, K.T.; Luhrsen, K.R.

    1986-01-01

    Elevated calcium consumption is reported to affect trace mineral bioavailability. The authors examined this phenomenon in both single dose radio-label test meals and an eight week feeding trial in rats. In the single dose studies, human milk, cows milk, and various calcium sources were examined in relation to radio-iron and radio-zinc retention. 59 Fe retention was greater from human milk than cows milk. However, when the calcium content of human milk was adjusted (with CaHPO 4 or CaCO 3 ) to equal the level in cows milk, iron retention was depressed. Similarly, when calcium sources (CaCO 3 , CaHPO 4 , hydroxy-apatite, bone meal) were examined at different calcium:metal molar ratios, the degree of inhibition on metal retention varied. In general, phosphate salts were more inhibiting than carbonates. In the feeding trial, calcium was fed in diets at normal (0.5%) or elevated (1.5%) levels. Serum, liver, kidney, and bone trace mineral profiles were obtained. In general, most trace elements showed decreased levels in the tissues. Zinc and iron were most striking, followed by magnesium with minor changes in copper. A high calcium:high mineral supplemented group was also fed. Mixed mineral supplementation prevented all calcium interactions. These data indicate the importance of calcium mineral interactions in bioavailability considerations in both milk sources and in mineral supplementation

  3. [Calcium hypothesis of Alzheimer disease].

    Riazantseva, M A; Mozhaeva, G N; Kaznacheeva, E V

    2012-01-01

    Alzheimer's disease is the most common neurodegenerative disorder characterized by progressive memory and cognitive abilities loss. The etiology of Alzheimer's disease is poorly understood. In this regard, there is no effective treatment for the disease. Various hypotheses to explain the nature of the pathology of Alzheimer's disease led to the development of appropriate therapeutics. Despite of decades of research and clinical trials available therapeutics, at best, can only slow down the progression of the disease, but cannot cure it. This review dedicated to the one of modern hypotheses of Alzheimer's disease pathogenesis implied the impairment of calcium homeostasis as a key event for the development of neurodegenerative processes.

  4. Calcium

    ... of new bone. People with lactose intolerance cannot digest this natural sugar found in milk and experience ... Disclaimer | FOIA | Información en español Download free Acrobat Reader Term Selected: Select the term below that you' ...

  5. Unnatural reactive amino acid genetic code additions

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, Christopher J.; Schultz, Peter G.

    2017-10-25

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  6. Encoded libraries of chemically modified peptides.

    Heinis, Christian; Winter, Greg

    2015-06-01

    The use of powerful technologies for generating and screening DNA-encoded protein libraries has helped drive the development of proteins as pharmaceutical ligands. However the development of peptides as pharmaceutical ligands has been more limited. Although encoded peptide libraries are typically several orders of magnitude larger than classical chemical libraries, can be more readily screened, and can give rise to higher affinity ligands, their use as pharmaceutical ligands is limited by their intrinsic properties. Two of the intrinsic limitations include the rotational flexibility of the peptide backbone and the limited number (20) of natural amino acids. However these limitations can be overcome by use of chemical modification. For example, the libraries can be modified to introduce topological constraints such as cyclization linkers, or to introduce new chemical entities such as small molecule ligands, fluorophores and photo-switchable compounds. This article reviews the chemistry involved, the properties of the peptide ligands, and the new opportunities offered by chemical modification of DNA-encoded peptide libraries. Copyright © 2015. Published by Elsevier Ltd.

  7. Encoding and decoding messages with chaotic lasers

    Alsing, P.M.; Gavrielides, A.; Kovanis, V.; Roy, R.; Thornburg, K.S. Jr.

    1997-01-01

    We investigate the structure of the strange attractor of a chaotic loss-modulated solid-state laser utilizing return maps based on a combination of intensity maxima and interspike intervals, as opposed to those utilizing Poincare sections defined by the intensity maxima of the laser (I=0,Ie<0) alone. We find both experimentally and numerically that a simple, intrinsic relationship exists between an intensity maximum and the pair of preceding and succeeding interspike intervals. In addition, we numerically investigate encoding messages on the output of a chaotic transmitter laser and its subsequent decoding by a similar receiver laser. By exploiting the relationship between the intensity maxima and the interspike intervals, we demonstrate that the method utilized to encode the message is vital to the system close-quote s ability to hide the signal from unwanted deciphering. In this work alternative methods are studied in order to encode messages by modulating the magnitude of pumping of the transmitter laser and also by driving its loss modulation with more than one frequency. copyright 1997 The American Physical Society

  8. cGMP-Dependent Protein Kinase Inhibition Extends the Upper Temperature Limit of Stimulus-Evoked Calcium Responses in Motoneuronal Boutons of Drosophila melanogaster Larvae.

    Krill, Jennifer L; Dawson-Scully, Ken

    2016-01-01

    While the mammalian brain functions within a very narrow range of oxygen concentrations and temperatures, the fruit fly, Drosophila melanogaster, has employed strategies to deal with a much wider range of acute environmental stressors. The foraging (for) gene encodes the cGMP-dependent protein kinase (PKG), has been shown to regulate thermotolerance in many stress-adapted species, including Drosophila, and could be a potential therapeutic target in the treatment of hyperthermia in mammals. Whereas previous thermotolerance studies have looked at the effects of PKG variation on Drosophila behavior or excitatory postsynaptic potentials at the neuromuscular junction (NMJ), little is known about PKG effects on presynaptic mechanisms. In this study, we characterize presynaptic calcium ([Ca2+]i) dynamics at the Drosophila larval NMJ to determine the effects of high temperature stress on synaptic transmission. We investigated the neuroprotective role of PKG modulation both genetically using RNA interference (RNAi), and pharmacologically, to determine if and how PKG affects presynaptic [Ca2+]i dynamics during hyperthermia. We found that PKG activity modulates presynaptic neuronal Ca2+ responses during acute hyperthermia, where PKG activation makes neurons more sensitive to temperature-induced failure of Ca2+ flux and PKG inhibition confers thermotolerance and maintains normal Ca2+ dynamics under the same conditions. Targeted motoneuronal knockdown of PKG using RNAi demonstrated that decreased PKG expression was sufficient to confer thermoprotection. These results demonstrate that the PKG pathway regulates presynaptic motoneuronal Ca2+ signaling to influence thermotolerance of presynaptic function during acute hyperthermia.

  9. Cross-talk between signaling pathways can generate robust oscillations in calcium and cAMP.

    Fernando Siso-Nadal

    Full Text Available BACKGROUND: To control and manipulate cellular signaling, we need to understand cellular strategies for information transfer, integration, and decision-making. A key feature of signal transduction is the generation of only a few intracellular messengers by many extracellular stimuli. METHODOLOGY/PRINCIPAL FINDINGS: Here we model molecular cross-talk between two classic second messengers, cyclic AMP (cAMP and calcium, and show that the dynamical complexity of the response of both messengers increases substantially through their interaction. In our model of a non-excitable cell, both cAMP and calcium concentrations can oscillate. If mutually inhibitory, cross-talk between the two second messengers can increase the range of agonist concentrations for which oscillations occur. If mutually activating, cross-talk decreases the oscillation range, but can generate 'bursting' oscillations of calcium and may enable better filtering of noise. CONCLUSION: We postulate that this increased dynamical complexity allows the cell to encode more information, particularly if both second messengers encode signals. In their native environments, it is unlikely that cells are exposed to one stimulus at a time, and cross-talk may help generate sufficiently complex responses to allow the cell to discriminate between different combinations and concentrations of extracellular agonists.

  10. Rare variants in calcium homeostasis modulator 1 (CALHM1 found in early onset Alzheimer's disease patients alter calcium homeostasis.

    Fanny Rubio-Moscardo

    Full Text Available Calcium signaling in the brain is fundamental to the learning and memory process and there is evidence to suggest that its dysfunction is involved in the pathological pathways underlying Alzheimer's disease (AD. Recently, the calcium hypothesis of AD has received support with the identification of the non-selective Ca(2+-permeable channel CALHM1. A genetic polymorphism (p. P86L in CALHM1 reduces plasma membrane Ca(2+ permeability and is associated with an earlier age-at-onset of AD. To investigate the role of CALHM1 variants in early-onset AD (EOAD, we sequenced all CALHM1 coding regions in three independent series comprising 284 EOAD patients and 326 controls. Two missense mutations in patients (p.G330D and p.R154H and one (p.A213T in a control individual were identified. Calcium imaging analyses revealed that while the mutation found in a control (p.A213T behaved as wild-type CALHM1 (CALHM1-WT, a complete abolishment of the Ca(2+ influx was associated with the mutations found in EOAD patients (p.G330D and p.R154H. Notably, the previously reported p. P86L mutation was associated with an intermediate Ca(2+ influx between the CALHM1-WT and the p.G330D and p.R154H mutations. Since neither expression of wild-type nor mutant CALHM1 affected amyloid ß-peptide (Aß production or Aß-mediated cellular toxicity, we conclude that rare genetic variants in CALHM1 lead to Ca(2+ dysregulation and may contribute to the risk of EOAD through a mechanism independent from the classical Aß cascade.

  11. Impaired body calcium metabolism with low bone density and compensatory colonic calcium absorption in cecectomized rats

    Jongwattanapisan, P.; Suntornsaratoon, P.; Wongdee, K.; Dorkkam, N.; Krishnamra, N.; Charoenphandhu, N.

    2012-01-01

    An earlier study reported that cecal calcium absorption contributes less than 10% of total calcium absorbed by the intestine, although the cecum has the highest calcium transport rate compared with other intestinal segments. Thus, the physiological significance of the cecum pertaining to body

  12. Effect of lowering dietary calcium intake on fractional whole body calcium retention

    Dawson-Hughes, B.; Stern, D.T.; Shipp, C.C.; Rasmussen, H.M.

    1988-01-01

    Although fractional calcium absorption is known to vary inversely with calcium intake, the extent and timing of individual hormonal and calcium absorption responses to altered calcium intake have not been defined. We measured fractional whole body retention of orally ingested 47 Ca, an index of calcium absorption, in nine normal women after they had eaten a 2000-mg calcium diet for 8 weeks and a 300-mg calcium diet for 1, 2, 4, and 8 weeks. After the diet change, serum intact PTH (32.2% increase; P = 0.005), serum 1,25-dihydroxyvitamin D [1,25-(OH)2D; 43.8% increase; P = 0.003], and fractional whole body calcium retention (42.8% increase; P = 0.004) increased within 1 week. Although the PTH and calcium retention responses remained fairly constant throughout the low calcium intake period, serum 1,25-(OH)2D concentrations declined toward baseline after week 1. Thus, the late increase in calcium retention may have resulted from calcium absorption that was independent of 1,25-(OH)2D stimulation

  13. Short communication: Urinary oxalate and calcium excretion by dogs and cats diagnosed with calcium oxalate urolithiasis

    Dijcker, J.C.; Kummeling, A.; Hagen-Plantinga, E.A.; Hendriks, W.H.

    2012-01-01

    Introduction Urine concentrations of oxalate and calcium play an important role in calcium oxalate (CaOx) urolith formation in dogs and cats, with high excretions of both substances increasing the chance of CaOx urolithiasis. In 17 CaOx-forming dogs, urine calcium:creatinine ratio (Ca:Cr) was found

  14. An overview of techniques for the measurement of calcium distribution, calcium fluxes, and cytosolic free calcium in mammalian cells

    Borle, A.B.

    1990-01-01

    An array of techniques can be used to study cell calcium metabolism that comprises several calcium compartments and many types of transport systems such as ion channels, ATP-dependent pumps, and antiporters. The measurement of total call calcium brings little information of value since 60 to 80% of total cell calcium is actually bound to the extracellular glycocalyx. Cell fractionation and differential centrifugation have been used to study intracellular Ca 2+ compartmentalization, but the methods suffer from the possibility of Ca 2+ loss or redistribution among cell fractions. Steady-state kinetic analyses of 45 Ca uptake or desaturation curves have been used to study the distribution of Ca 2+ among various kinetic pools in living cells and their rate of Ca 2+ exchange, but the analyses are constrained by many limitations. Nonsteady-state tracer studies can provide information about rapid changes in calcium influx or efflux in and out of the cell. Zero-time kinetics of 45 Ca uptake can detect instantaneous changes in calcium influx, while 45 Ca fractional efflux ratio, can detect rapid stimulations or inhibitions of calcium efflux out of cells. The best strategy to study cell calcium metabolism is to use several different methods that focus on a specific problem from widely different angles

  15. Research applications of calcium-47

    1962-01-01

    The possibility of using the isotope calcium-47 for calcium metabolism investigation was discussed. It seemed particularly suited for this purpose since it has a half-life of only 4.7 days; it is, moreover, a strong gamma-emitter which permits easy detection of very small quantities from outside the body. It was, however, produced on an experimental basis only and at a price of US $1400 per mC which was beyond the financial possibilities of almost any medical research institution or hospital. In view of IAEA's mandate to promote isotope research in the fields of radiobiology and medicine the participants asked the Agency to carry out a programme of encouraging research that might lead to cheaper methods of producing this isotope and of assisting in its practical applications in diagnosis and clinical research. The Agency took up this suggestion and the way it has pursued the project might be considered characteristic of its methods of dealing with such problems on an international scale

  16. Research applications of calcium-47

    NONE

    1962-04-15

    The possibility of using the isotope calcium-47 for calcium metabolism investigation was discussed. It seemed particularly suited for this purpose since it has a half-life of only 4.7 days; it is, moreover, a strong gamma-emitter which permits easy detection of very small quantities from outside the body. It was, however, produced on an experimental basis only and at a price of US $1400 per mC which was beyond the financial possibilities of almost any medical research institution or hospital. In view of IAEA's mandate to promote isotope research in the fields of radiobiology and medicine the participants asked the Agency to carry out a programme of encouraging research that might lead to cheaper methods of producing this isotope and of assisting in its practical applications in diagnosis and clinical research. The Agency took up this suggestion and the way it has pursued the project might be considered characteristic of its methods of dealing with such problems on an international scale

  17. Genetics of osteoporosis

    Urano, Tomohiko [Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655 (Japan); Inoue, Satoshi, E-mail: INOUE-GER@h.u-tokyo.ac.jp [Department of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655 (Japan); Department of Anti-Aging Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655 (Japan); Division of Gene Regulation and Signal Transduction, Research Center for Genomic Medicine, Saitama Medical University, Saitama (Japan)

    2014-09-19

    Highlights: • Single-nucleotide polymorphisms (SNPs) associated with osteoporosis were identified. • SNPs mapped close to or within VDR and ESR1 are associated with bone mineral density. • WNT signaling pathway plays a pivotal role in regulating bone mineral density. • Genetic studies will be useful for identification of new therapeutic targets. - Abstract: Osteoporosis is a skeletal disease characterized by low bone mineral density (BMD) and microarchitectural deterioration of bone tissue, which increases susceptibility to fractures. BMD is a complex quantitative trait with normal distribution and seems to be genetically controlled (in 50–90% of the cases), according to studies on twins and families. Over the last 20 years, candidate gene approach and genome-wide association studies (GWAS) have identified single-nucleotide polymorphisms (SNPs) that are associated with low BMD, osteoporosis, and osteoporotic fractures. These SNPs have been mapped close to or within genes including those encoding nuclear receptors and WNT-β-catenin signaling proteins. Understanding the genetics of osteoporosis will help identify novel candidates for diagnostic and therapeutic targets.

  18. Genetics of Vitiligo

    Spritz, Richard; Andersen, Genevieve

    2016-01-01

    Synopsis Vitiligo is “complex disorder” (also termed polygenic and multifactorial), reflecting simultaneous contributions of multiple genetic risk factors and environmental triggers. Large-scale genome-wide association studies, principally in European-derived whites and in Chinese, have discovered approximately 50 different genetic loci that contribute to vitiligo risk, some of which also contribute to other autoimmune diseases that are epidemiologically associated with vitiligo. At many of these vitiligo susceptibility loci the corresponding relevant genes have now been identified, and for some of these genes the specific DNA sequence variants that contribute to vitiligo risk are also now known. A large fraction of these genes encode proteins involved in immune regulation, a number of others play roles in cellular apoptosis, and still others are involved in regulating functions of melanocytes. For this last group, there appears to be an opposite relationship between susceptibility to vitiligo and susceptibility to melanoma, suggesting that vitiligo may engage a normal mechanism of immune surveillance for melanoma. While many of the specific biologic mechanisms through which these genetic factors operate to cause vitiligo remain to be elucidated, it is now clear that vitiligo is an autoimmune disease involving a complex relationship between programming and function of the immune system, aspects of the melanocyte autoimmune target, and dysregulation of the immune response. PMID:28317533

  19. Codissolution of calcium hydrogenphosphate and sodium hydrogencitrate in water. Spontaneous supersaturation of calcium citrate increasing calcium bioavailability

    Hedegaard, Martina Vavrusova; Danielsen, Bente Pia; Garcia, André Castilho

    2018-01-01

    The sparingly soluble calcium hydrogenphosphate dihydrate, co-dissolving in water during dissolution of freely soluble sodium hydrogencitrate sesquihydrate as caused by proton transfer from hydrogencitrate to hydrogenphosphate, was found to form homogenous solutions supersaturated by a factor up...... to 8 in calcium citrate tetrahydrate. A critical hydrogencitrate concentration for formation of homogeneous solutions was found to depend linearly on dissolved calcium hydrogenphosphate: [HCitr2-] = 14[CaHPO4] - 0.05 at 25 °C. The lag phase for precipitation of calcium citrate tetrahydrate......, as identified from FT-IR spectra, from these spontaneously formed supersaturated solutions was several hours, and the time to reach solubility equilibrium was several days. Initial calcium ion activity was found to be almost independent of the degree of supersaturation as determined electrochemically...

  20. CALCIUM AND THE PREVENTION OF COLON CANCER

    WELBERG, JWM; KLEIBEUKER, JH; VANDERMEER, R; MULDER, NH; DEVRIES, EGE

    1991-01-01

    Diet is a major determinant of colon cancer risk. Calcium may protect against colon cancer, presumably by binding cytotoxic bile acids and fatty acids. Numerous studies support this proposition. In subjects at risk for colon cancer oral calcium supplementation has been shown to reduce rectal

  1. Comparison of Serum Calcium and Magnesium Between ...

    Background: Evidence suggests the involvement of calcium and magnesium metabolism in the pathophysiology of preeclampsia. However, findings from studies are heterogenous and inconsistent. Aim: The study aimed to compare the total serum calcium and magnesium levels in preeclamptic women with that of ...

  2. Fast kinetics of calcium dissociation from calsequestrin

    MARIANELA BELTRÁN

    2006-01-01

    Full Text Available We measured the kinetics of calcium dissociation from calsequestrin in solution or forming part of isolated junctional sarcoplasmic reticulum membranes by mixing calsequestrin equilibrated with calcium with calcium-free solutions in a stopped-flow system. In parallel, we measured the kinetics of the intrinsic fluorescence changes that take place following calcium dissociation from calsequestrin. We found that at 25ºC calcium dissociation was 10-fold faster for calsequestrin attached to junctional membranes (k = 109 s-1 than in solution. These results imply that calcium dissociation from calsequestrin in vivo is not rate limiting during excitation-contraction coupling. In addition, we found that the intrinsic fluorescence decrease for calsequestrin in solution or forming part of junctional membranes was significantly slower than the rates of calcium dissociation. The kinetics of intrinsic fluorescence changes had two components for calsequestrin associated to junctional membranes and only one for calsequestrin in solution; the faster component was 8-fold faster (k = 54.1 s-1 than the slower component (k = 6.9 s-1, which had the same k value as for calsequestrin in solution. These combined results suggest that the presence of calsequestrin at high concentrations in a restricted space, such as when bound to the junctional membrane, accelerates calcium dissociation and the resulting structural changes, presumably as a result of cooperative molecular interactions.

  3. Calcium, snails, and birds: a case study

    R. Mänd

    2000-10-01

    Full Text Available Recent studies have shown that wild birds breeding in acidified areas have difficulties with obtaining sufficient calcium for their eggshells, and that the cause of it is the shortage of land snails. Many birds have to search for Ca-rich snail shells on a daily basis during egg production. Molluscs depend on litter calcium, which has decreased due to acidification of the environment. Calcium limitation may be a widespread phenomenon also in non-acidified, naturally Ca-poor areas. The problem is that while in the latter areas the time for development of specific adaptations may have been sufficient, then in acidified areas, on the contrary, calcium shortage is a recent phenomenon. Therefore, since the extent of calcium limitation in non-acidified areas is hard to derive from observational data, experimental approach is needed. We provide experimental evidence that specific calcium deficit does affect reproductive traits also in the birds breeding in naturally base-poor habitats. Our study was conducted in a heterogeneous woodland area in Estonia containing deciduous forest patches as well as base-poor pine forest with low snail abundance. Ca supplementation, using snail shell and chicken eggshell fragments, was carried out for pied flycatchers and great tits. Extra calcium affected positively several reproductive traits like egg volume and eggshell thickness, start of breeding, and fledglings’ parameters. The negative relationship between calcium availability and lay-date suggests that birds adjust their breeding tactics to conditions of Ca deficiency, for example, by postponing laying.

  4. In vivo calcium metabolism by IRMS

    Public policy initiatives related to enhancing the health of populations, increasingly seek to identify meaningful biological outcomes on which to determine age-related nutritional requirements. For calcium, the primary outcome of interest is the availability of calcium in the diet for bone formatio...

  5. 21 CFR 172.715 - Calcium lignosulfonate.

    2010-04-01

    ... Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) FOOD ADDITIVES PERMITTED FOR DIRECT ADDITION TO FOOD FOR HUMAN CONSUMPTION Other Specific Usage Additives § 172.715 Calcium lignosulfonate. Calcium lignosulfonate may be...

  6. Sensory analysis of calcium-biofortified lettuce

    Vegetables represent an attractive means of providing increased calcium nutrition to the public. In this study, it was demonstrated that lettuce expressing the deregulated Arabidopsis H(+)/Ca(2+) transporter sCAX1 (cation exchanger 1) contained 25-32% more calcium than controls. These biofortified l...

  7. 21 CFR 184.1187 - Calcium alginate.

    2010-04-01

    ... ingredient is used in food only within the following specific limitations: Category of food Maximum level of... other food categories 0.3 Do. (d) Prior sanctions for calcium alginate different from the uses... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium alginate. 184.1187 Section 184.1187 Food...

  8. Calcium supplementation in osteoporosis: useful or harmful?

    Chiodini, Iacopo; Bolland, Mark J

    2018-04-01

    Osteoporosis and fragility fractures are important social and economic problems worldwide and are due to both the loss of bone mineral density and sarcopenia. Indeed, fragility fractures are associated with increased disability, morbidity and mortality. It is known that a normal calcium balance together with a normal vitamin D status is important for maintaining well-balanced bone metabolism, and for many years, calcium and vitamin D have been considered crucial in the prevention and treatment of osteoporosis. However, recently, the usefulness of calcium supplementation (alone or with concomitant vitamin D) has been questioned, since some studies reported only weak efficacy of these supplementations in reducing fragility fracture risk. On the other hand, besides the gastrointestinal side effects of calcium supplements and the risk of kidney stones related to use of co-administered calcium and vitamin D supplements, other recent data suggested potential adverse cardiovascular effects from calcium supplementation. This debate article is focused on the evidence regarding both the possible usefulness for bone health and the potential harmful effects of calcium and/or calcium with vitamin D supplementation. © 2018 European Society of Endocrinology.

  9. Elements from chlorine to calcium nuclear reactions

    Kunz, Wunibald

    1968-01-01

    Nuclear Tables: Part II Nuclear Reactions, Volume 3: The Elements from Chlorine to Calcium contains tabulations of the nuclear reaction values of elements chlorine, argon, potassium, and calcium. These tabulations provide the calculated Q-values of the elements and their isotopes. This book will be of value to general chemistry researchers.

  10. Oligofructose stimulates calcium absorption in adolescents

    Heuvel, E.G.H.M. van den; Muys, T.; Dokkum, W. van; Schaafsma, G.

    1999-01-01

    Background: In rats, nondigestible oligosaccharides stimulate calcium absorption. Recently, this effect was also found in human subjects. Objective: The objective of the study was to investigate whether consumption of 15 g oligofructose/d stimulates calcium absorption in male adolescents. Design:

  11. Rates of calcium carbonate removal from soils.

    Breemen, van N.; Protz, R.

    1988-01-01

    Mean annual rates of calcium carbonate removal from soils in a subarctic climate estimated from data on two chronosequences of calcareous storm ridges, appeared to be relatively constant through time. Concentrations of dissolved calcium carbonate in the soil solution in the study sites calculated

  12. Role of Virus-Encoded microRNAs in Avian Viral Diseases

    Yongxiu Yao

    2014-03-01

    Full Text Available With total dependence on the host cell, several viruses have adopted strategies to modulate the host cellular environment, including the modulation of microRNA (miRNA pathway through virus-encoded miRNAs. Several avian viruses, mostly herpesviruses, have been shown to encode a number of novel miRNAs. These include the highly oncogenic Marek’s disease virus-1 (26 miRNAs, avirulent Marek’s disease virus-2 (36 miRNAs, herpesvirus of turkeys (28 miRNAs, infectious laryngotracheitis virus (10 miRNAs, duck enteritis virus (33 miRNAs and avian leukosis virus (2 miRNAs. Despite the closer antigenic and phylogenetic relationship among some of the herpesviruses, miRNAs encoded by different viruses showed no sequence conservation, although locations of some of the miRNAs were conserved within the repeat regions of the genomes. However, some of the virus-encoded miRNAs showed significant sequence homology with host miRNAs demonstrating their ability to serve as functional orthologs. For example, mdv1-miR-M4-5p, a functional ortholog of gga-miR-155, is critical for the oncogenicity of Marek’s disease virus. Additionally, we also describe the potential association of the recently described avian leukosis virus subgroup J encoded E (XSR miRNA in the induction of myeloid tumors in certain genetically-distinct chicken lines. In this review, we describe the advances in our understanding on the role of virus-encoded miRNAs in avian diseases.

  13. Calcium homeostasis modulator (CALHM) ion channels.

    Ma, Zhongming; Tanis, Jessica E; Taruno, Akiyuki; Foskett, J Kevin

    2016-03-01

    Calcium homeostasis modulator 1 (CALHM1), formerly known as FAM26C, was recently identified as a physiologically important plasma membrane ion channel. CALHM1 and its Caenorhabditis elegans homolog, CLHM-1, are regulated by membrane voltage and extracellular Ca(2+) concentration ([Ca(2+)]o). In the presence of physiological [Ca(2+)]o (∼1.5 mM), CALHM1 and CLHM-1 are closed at resting membrane potentials but can be opened by strong depolarizations. Reducing [Ca(2+)]o increases channel open probability, enabling channel activation at negative membrane potentials. Together, voltage and Ca(2+) o allosterically regulate CALHM channel gating. Through convergent evolution, CALHM has structural features that are reminiscent of connexins and pannexins/innexins/LRRC8 (volume-regulated anion channel (VRAC)) gene families, including four transmembrane helices with cytoplasmic amino and carboxyl termini. A CALHM1 channel is a hexamer of CALHM1 monomers with a functional pore diameter of ∼14 Å. CALHM channels discriminate poorly among cations and anions, with signaling molecules including Ca(2+) and ATP able to permeate through its pore. CALHM1 is expressed in the brain where it plays an important role in cortical neuron excitability induced by low [Ca(2+)]o and in type II taste bud cells in the tongue that sense sweet, bitter, and umami tastes where it functions as an essential ATP release channel to mediate nonsynaptic neurotransmitter release. CLHM-1 is expressed in C. elegans sensory neurons and body wall muscles, and its genetic deletion causes locomotion defects. Thus, CALHM is a voltage- and Ca(2+) o-gated ion channel, permeable to large cations and anions, that plays important roles in physiology.

  14. Genetic modification and genetic determinism

    Vorhaus Daniel B

    2006-06-01

    Full Text Available Abstract In this article we examine four objections to the genetic modification of human beings: the freedom argument, the giftedness argument, the authenticity argument, and the uniqueness argument. We then demonstrate that each of these arguments against genetic modification assumes a strong version of genetic determinism. Since these strong deterministic assumptions are false, the arguments against genetic modification, which assume and depend upon these assumptions, are therefore unsound. Serious discussion of the morality of genetic modification, and the development of sound science policy, should be driven by arguments that address the actual consequences of genetic modification for individuals and society, not by ones propped up by false or misleading biological assumptions.

  15. The calcium and vitamin D controversy

    Abrahamsen, Bo

    2017-01-01

    Areas of the world where vitamin D levels are low for months of the year and intakes of calcium are high have a high prevalence of osteoporosis and cardiovascular disease. This suggests a public health message of avoiding calcium supplements and increasing vitamin D intake. No message could be more...... welcome as vitamin D can be given as a bolus while calcium must be taken daily and may be poorly tolerated. This approach is based on no evidence from intervention studies. Randomized controlled trials (RCTs) suggest that vitamin D given with calcium elicits a small reduction in fracture risk and deaths....... This has not been demonstrated for D given alone. The cardiovascular safety of calcium and vitamin D (CaD) supplements is difficult to ascertain due to weaknesses in RCT designs and adjudication that cannot be remedied by subanalysis. Moreover, no major new RCTs are in process to provide better evidence...

  16. Application of Calcium Phosphate Materials in Dentistry

    Jabr S. Al-Sanabani

    2013-01-01

    Full Text Available Calcium phosphate materials are similar to bone in composition and in having bioactive and osteoconductive properties. Calcium phosphate materials in different forms, as cements, composites, and coatings, are used in many medical and dental applications. This paper reviews the applications of these materials in dentistry. It presents a brief history, dental applications, and methods for improving their mechanical properties. Notable research is highlighted regarding (1 application of calcium phosphate into various fields in dentistry; (2 improving mechanical properties of calcium phosphate; (3 biomimetic process and functionally graded materials. This paper deals with most common types of the calcium phosphate materials such as hydroxyapatite and tricalcium phosphate which are currently used in dental and medical fields.

  17. Evaluating standard terminologies for encoding allergy information.

    Goss, Foster R; Zhou, Li; Plasek, Joseph M; Broverman, Carol; Robinson, George; Middleton, Blackford; Rocha, Roberto A

    2013-01-01

    Allergy documentation and exchange are vital to ensuring patient safety. This study aims to analyze and compare various existing standard terminologies for representing allergy information. Five terminologies were identified, including the Systemized Nomenclature of Medical Clinical Terms (SNOMED CT), National Drug File-Reference Terminology (NDF-RT), Medication Dictionary for Regulatory Activities (MedDRA), Unique Ingredient Identifier (UNII), and RxNorm. A qualitative analysis was conducted to compare desirable characteristics of each terminology, including content coverage, concept orientation, formal definitions, multiple granularities, vocabulary structure, subset capability, and maintainability. A quantitative analysis was also performed to compare the content coverage of each terminology for (1) common food, drug, and environmental allergens and (2) descriptive concepts for common drug allergies, adverse reactions (AR), and no known allergies. Our qualitative results show that SNOMED CT fulfilled the greatest number of desirable characteristics, followed by NDF-RT, RxNorm, UNII, and MedDRA. Our quantitative results demonstrate that RxNorm had the highest concept coverage for representing drug allergens, followed by UNII, SNOMED CT, NDF-RT, and MedDRA. For food and environmental allergens, UNII demonstrated the highest concept coverage, followed by SNOMED CT. For representing descriptive allergy concepts and adverse reactions, SNOMED CT and NDF-RT showed the highest coverage. Only SNOMED CT was capable of representing unique concepts for encoding no known allergies. The proper terminology for encoding a patient's allergy is complex, as multiple elements need to be captured to form a fully structured clinical finding. Our results suggest that while gaps still exist, a combination of SNOMED CT and RxNorm can satisfy most criteria for encoding common allergies and provide sufficient content coverage.

  18. Oral calcium carbonate affects calcium but not phosphorus balance in stage 3–4 chronic kidney disease

    Hill, Kathleen M.; Martin, Berdine R.; Wastney, Meryl; McCabe, George P.; Moe, Sharon M.; Weaver, Connie M.; Peacock, Munro

    2014-01-01

    Chronic kidney disease (CKD) patients are given calcium carbonate to bind dietary phosphorus and reduce phosphorus retention, and to prevent negative calcium balance. Data are limited on calcium and phosphorus balance in CKD to support this. The aim of this study was to determine calcium and phosphorus balance and calcium kinetics with and without calcium carbonate in CKD patients. Eight stage 3/4 CKD patients, eGFR 36 mL/min, participated in two 3-week balances in a randomized placebo-controlled cross-over study of calcium carbonate (1500 mg/d calcium). Calcium and phosphorus balance were determined on a controlled diet. Oral and intravenous 45calcium with blood sampling and urine and fecal collections were used for calcium kinetics. Fasting blood and urine were collected at baseline and end of each week of each balance period for biochemical analyses. Results showed that patients were in neutral calcium and phosphorus balance while on placebo. Calcium carbonate produced positive calcium balance, did not affect phosphorus balance, and produced only a modest reduction in urine phosphorus excretion compared with placebo. Calcium kinetics demonstrated positive net bone balance but less than overall calcium balance suggesting tissue deposition. Fasting biochemistries of calcium and phosphate homeostasis were unaffected by calcium carbonate. If they can be extrapolated to effects of chronic therapy, these data caution against the use of calcium carbonate as a phosphate binder. PMID:23254903

  19. 2D Barcode for DNA Encoding

    Elena Purcaru; Cristian Toma

    2011-01-01

    The paper presents a solution for endcoding/decoding DNA information in 2D barcodes. First part focuses on the existing techniques and symbologies in 2D barcodes field. The 2D barcode PDF417 is presented as starting point. The adaptations and optimizations on PDF417 and on DataMatrix lead to the solution - DNA2DBC - DeoxyriboNucleic Acid Two Dimensional Barcode. The second part shows the DNA2DBC encoding/decoding process step by step. In conclusions are enumerated the most important features ...

  20. Dual beam encoded extended fractional Fourier transform security ...

    This paper describes a simple method for making dual beam encoded extended fractional Fourier transform (EFRT) security holograms. The hologram possesses different stages of encoding so that security features are concealed and remain invisible to the counterfeiter. These concealed and encoded anticounterfeit ...